eScholarship@UMMS

The impact of age on the incidence and prognosis of initial acute myocardial infarction: the Worcester Heart Attack Study.

Robert J. Goldberg — Thu, 05 Nov 2009 13:44:19 PST

As part of a community-wide study examining time trends in the incidence and case-fatality rates (CFR) of patients hospitalized with acute myocardial infarction (MI) in sixteen hospitals in the Worcester, Massachusetts metropolitan area, the association of age to the incidence rates of initial acute MI and to in-hospital and long-term survival among 2115 patients with validated acute MI was examined. After selected age-specific changes in the incidence rates of initial events of acute MI between 1975 and 1981, the incidence rates of acute MI markedly declined between 1981 and 1984, resulting in decreases in the age-specific incidence rates of initial acute MI between 1975 and 1984. For the combined study periods, the in-hospital CFR of acute MI increased from 5.0% in patients less than 55 years of age to 7.9% in those 55 to 64 years, to 16.1% in those 65 to 74 years and to 32.1% in patients 75 years of age and older. Among discharged hospital survivors, increasing age was related to poorer long-term survival over a 5-year follow-up period. The results of this population-based study reinforce the need for, and importance of, modification of coronary risk factors in both young and older individuals, and of focused therapeutic efforts to salvage jeopardized myocardium in elderly patients hospitalized with acute MI.

Old age--is it a risk for adverse drug reactions?

Jerry H. Gurwitz — Thu, 05 Nov 2009 13:44:18 PST

Pharmacotherapy is often the single most important medical intervention in the care of the elderly. However, there are obvious concerns about the vulnerability of this group to adverse drug reactions (ADRs). A rapidly accumulating literature regarding changes in pharmacokinetics and pharmacodynamics with advancing age suggests a strong pharmacologic basis for such concerns. Yet, the results of epidemiologic studies exploring the relationship between age and ADRs are ambiguous. Interpretation of the results of these studies is limited by inconsistent definitions of outcomes of interest and failure to control for important age-related covariates including the clinical status of the patient and the number of medications that a patient is receiving. Some recent studies have investigated age-related aspects of specific adverse consequences of drug therapy. For example, age, in and of itself, does not appear to be a risk factor for bleeding complications of warfarin therapy. Older patients may actually be at less risk than younger patients to experience depression associated with beta-blocker therapy. Although examination of data from premarketing studies might be considered a promising strategy to explore the relationship between age and ADR risk, the small number of truly elderly subjects included in these studies greatly limits their usefulness. Postmarketing studies utilizing databases containing clinical data for large numbers of older patients may provide the optimal approach for investigating whether old age is an independent risk factor for ADRs.

Improving medication prescribing and utilization in the nursing home.

Jerry H. Gurwitz — Thu, 05 Nov 2009 13:44:16 PST

There is ample and compelling evidence to suggest that medications are frequently used inappropriately in the nursing home. The occurrence of avoidable adverse drug reactions is the most serious consequence of inappropriate prescribing; economic implications are also of interest. With increasing concern over the quality of care in nursing homes, and with the revision of regulations governing such care by the Health Care Financing Administration, it is important to consider the experience thus far in monitoring and improving drug use in nursing homes. A number of studies have investigated approaches designed to reduce inappropriate prescribing and drug utilization in this setting. In contrast to the wide range of approaches that have been evaluated and implemented in the hospital setting, interventions in the nursing home have centered primarily around consultant-pharmacist activities. Although these activities are now federally mandated in all nursing homes, there is little evidence from adequately controlled studies to document their impact or cost-effectiveness. By contrast, face-to-face educational interventions directed at physicians ("academic detailing") have been shown to be effective in improving prescribing for some medications. The prominent role played by the nursing staff in the utilization of many medications in the nursing home implies that an educational intervention excluding nursing staff would be insufficient to influence drug utilization positively in many situations (eg, psychoactive medications and laxatives). Future research efforts must pay greater attention to adequate study design considerations as well as to the clinical outcomes of such interventions and their cost-effectiveness.

Nonsteroidal anti-inflammatory drug-associated azotemia in the very old.

Jerry H. Gurwitz — Thu, 05 Nov 2009 13:44:15 PST

We conducted a prospective study in 114 elderly patients to determine the renal effects of short-term therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) in the very old. Study subjects were patients in a long-term care facility (mean age, 87 years) newly begun on a regimen of NSAID therapy. For the study group as a whole, the serum urea nitrogen level rose 1.7 mmol/L 5 to 7 days after initiation of therapy, with no significant changes in serum creatinine or potassium levels. In a comparison group of 45 patients not receiving NSAID therapy, no significant change in the serum urea nitrogen level was noted during a similar period. A subgroup of 15 patients (13%) experienced a greater than 50% increase in the serum urea nitrogen level during NSAID therapy, with a mean increase of 89% (8.6 mmol/L). A return to the baseline level occurred within 14 days after discontinuation of NSAID therapy. Two factors were significantly predictors of a greater than 50% increase in the serum urea nitrogen level: concurrent loop diuretic therapy (odds ratio, 2.2) and high NSAID dose (odds ratio, 2.0). These findings suggest that reversible azotemia develops in a sizable proportion of the very old who are treated with short-term NSAID therapy.

Coronary thrombolysis for the elderly?

Jerry H. Gurwitz — Thu, 05 Nov 2009 13:44:14 PST

The ambiguous relation between aging and adverse drug reactions.

Jerry H. Gurwitz — Thu, 05 Nov 2009 13:44:12 PST

PURPOSE: To examine the evidence for a relation between advancing patient age and the risk for adverse drug reactions. DATA SOURCE: A computer-assisted search of the English-language literature (MEDLINE, 1966 to 1990) followed by selective review of all pertinent articles. STUDY SELECTION: Studies that stratified data on adverse drug reactions by patient age were screened for review. Article selection was not limited by study design; the relation between age and the occurrence of adverse drug reactions did not have to be a primary focus of the study. DATA EXTRACTION: Pertinent data were abstracted from the results of case-control and cohort studies and from clinical trials. The methodologic strengths and weaknesses of these studies are discussed with particular reference to gerontologic issues. RESULTS OF DATA SYNTHESIS: Most studies have neglected the issue of whether the increased frequency of adverse drug reactions in the elderly is attributable to age alone or to the fact that older patients are more likely to have coexisting illnesses and to be taking several medications. Studies that combine all drug exposures for each patient and report the risk for any adverse effect provide little useful information about the risks associated with specific drug therapies in the elderly. The association between age and the risk for adverse drug reactions is best examined for individual pharmacologic agents. However, the exclusion of elderly subjects from clinical trials makes the determination of age effects impossible in many studies. Where subjects do represent an adequate age range, most studies fail to control for important clinical differences among subjects of different ages to distinguish the independent effects of chronologic age. CONCLUSION: Conventional clinical wisdom suggests that the risk for adverse drug reactions increases with advancing age, but available data do not confirm this "truism" of geriatric medicine. The inter-individual variability of the aging process, including the non-uniform nature of the pharmacokinetic and pharmacodynamic changes that occur with aging, indicates that clinical reality is far more complex. Patient-specific physiologic and functional characteristics are probably more important than any chronologic measure in predicting both adverse and beneficial outcomes associated with specific drug therapies.

Chromatin immunoprecipitation (ChIP) coupled to detection by quantitative real-time PCR to study transcription factor binding to DNA in Caenorhabditis elegans

Arnab Mukhopadhyay — Thu, 05 Nov 2009 11:35:45 PST

In order to determine how signaling pathways differentially regulate gene expression, it is necessary to identify the interactions between transcription factors (TFs) and their cognate cis-regulatory DNA elements. Here, we have outlined a chromatin immunoprecipitation (ChIP) protocol for use in whole Caenorhabditis elegans extracts. We discuss optimization of the procedure, including growth and harvesting of the worms, formaldehyde fixation, TF immunoprecipitation and analysis of bound sequences through real-time PCR. It takes approximately 10-12 d to obtain the worm culture for ChIP; the ChIP procedure is spaced out over a period of 2.5 d with two overnight incubations.

Dantrolene: mechanisms of neuroprotection and possible clinical applications in the neurointensive care unit

Susanne Muehlschlegel — Thu, 05 Nov 2009 11:35:40 PST

Calcium plays a central role in neuronal function and injury. Dantrolene, an inhibitor of the ryanodine receptor, inhibits intracellular calcium release from the sarco-endoplasmic reticulum. We review the available data of dantrolene as a potential neuroprotective agent and briefly summarize its other pharmacologic effects that may have potential applications for patients in the neurointensive care unit (NICU). Areas with the need for continued research are identified.

Dantrolene mediates vasorelaxation in cerebral vasoconstriction: a case series

Susanne Muehlschlegel — Thu, 05 Nov 2009 11:35:35 PST

INTRODUCTION: Cerebral vasoconstriction syndromes such as vasospasm after subarachnoid hemorrhage (SAH) and trauma, or Call-Fleming syndrome are difficult to treat, and can lead to substantial disability and death. Dantrolene, a ryanodine receptor antagonist, inhibits intracellular calcium release from the sarco-endoplasmic reticulum. We examined the effect of dantrolene on middle cerebral artery (MCA) blood flow velocities as measured by transcranial Doppler (TCD). METHODS: Three consecutive patients with elevated MCA TCD velocities receiving dantrolene (2.5 mg/kg i.v. q6h) were retrospectively reviewed. Average MCA peak systolic, mean flow velocities, and the pulsatility index (PI) before and after the dantrolene infusion were compared within patients. Systemic physiological parameters (blood pressure, heart rate, central venous pressure, intracranial pressure, body temperature, and cooling water temperature) were retrospectively collected 6 h before and after the dantrolene infusion. RESULTS: MCA peak systolic velocities (mean +/- SE) for the three patients were 297 +/- 3, 248 +/- 8, and 268 +/- 19 cm/s before dantrolene and 159 +/- 9, 169 +/- 8, and 216 +/- 12 cm/s after dantrolene. Average mean flow velocities showed the same trend. Interestingly, the PI increased slightly from 0.6, 0.52, and 0.67 before dantrolene, to 1.17, 0.71, and 0.77 after dantrolene. Systemic physiological parameters remained stable in all three patients. CONCLUSION: Dantrolene attenuated cerebral vasoconstriction as measured by TCD without altering systemic physiological parameters. This suggests that intracellular calcium release from ryanodine channels in smooth muscle might play a role in vasospasm. A prospective study is underway to test this hypothesis.

Loss of miRNA biogenesis induces p19Arf-p53 signaling and senescence in primary cells

Rajini R. Mudhasani — Thu, 05 Nov 2009 11:35:30 PST

Dicer, an enzyme involved in microRNA (miRNA) maturation, is required for proper cell differentiation and embryogenesis in mammals. Recent evidence indicates that Dicer and miRNA may also regulate tumorigenesis. To better characterize the role of miRNA in primary cell growth, we generated Dicer-conditional mice. Ablation of Dicer and loss of mature miRNAs in embryonic fibroblasts up-regulated p19(Arf) and p53 levels, inhibited cell proliferation, and induced a premature senescence phenotype that was also observed in vivo after Dicer ablation in the developing limb and in adult skin. Furthermore, deletion of the Ink4a/Arf or p53 locus could rescue fibroblasts from premature senescence induced by Dicer ablation. Although levels of Ras and Myc oncoproteins appeared unaltered, loss of Dicer resulted in increased DNA damage and p53 activity in these cells. These results reveal that loss of miRNA biogenesis activates a DNA damage checkpoint, up-regulates p19(Arf)-p53 signaling, and induces senescence in primary cells.

Trp53 deletion stimulates the formation of metastatic pancreatic tumors

Jennifer P. Morton — Thu, 05 Nov 2009 11:35:24 PST

The presence of distant metastases is a common finding on diagnosis of pancreatic cancer; however, the mechanisms underlying the dissemination of this tumor type remain poorly understood. Loss of the p53 tumor suppressor protein has been associated with tumor progression and metastasis in several tumor types including pancreatic ductal adenocarcinoma. Here, we describe the generation of a progressive and metastatic pancreatic cancer mouse model after the somatic and sporadic delivery of avian retroviruses encoding the mouse polyoma virus middle T antigen to elastase-tv-a transgenic mice with a pancreas-specific deletion of the Trp53 tumor suppressor locus. In this model, the tumors metastasize most frequently to the liver, consistent with human pancreatic carcinomas. Analysis of metastatic lesions demonstrated that concomitant loss of the Ink4a/Arf locus was not required for metastasis; however, pancreas-specific deletion of a single Ink4a/Arf allele cooperated with Trp53 deletion in a haploinsufficient manner to accelerate tumor development. Thus, our findings illustrate the potential role of p53 loss of function in pancreatic tumor progression, demonstrate the feasibility of modeling pancreatic cancer metastasis after somatic and sporadic oncogene activation, and indicate that our model may provide a useful experimental system for investigation of the molecular mechanisms underlying pancreatic cancer progression and metastasis.

P2Y12 antagonism: promises and challenges

Alan D. Michelson — Thu, 05 Nov 2009 11:35:19 PST

The P2Y12 antagonist clopidogrel has a well-established role as an antithrombotic agent in the settings of percutaneous coronary intervention and acute coronary syndromes. However, several challenges remain, including the relatively slow onset of action of clopidogrel and the phenomenon of clopidogrel response variability or "resistance". Novel P2Y12 antagonists, including prasugrel, AZD6140, and cangrelor, have a faster onset of action, as well as more potent, and less variable, inhibition of platelet function ex vivo. Whether this promise will be translated into clinical benefit for patients will be determined by the results of ongoing phase 3 clinical trials.

An Assessment of a Low-Cost Visual Tracking System (VTS) to Detect and Compensate for Patient Motion during SPECT

Joseph E. McNamara — Thu, 05 Nov 2009 11:35:14 PST

Patient motion is inevitable in SPECT and PET due to the lengthy period of time patients are imaged and patient motion can degrade diagnostic accuracy. The goal of our studies is to perfect a methodology for tracking and correcting patient motion when it occurs. In this paper we report on enhancements to the calibration, camera stability, accuracy of motion tracking, and temporal synchronization of a low-cost visual tracking system (VTS) we are developing. The purpose of the VTS is to track the motion of retro-reflective markers on stretchy bands wrapped about the chest and abdomen of patients. We have improved the accuracy of 3D spatial calibration by using a MATLAB optical camera calibration package with a planar calibration pattern. This allowed us to determine the intrinsic and extrinsic parameters for stereo-imaging with our CCD cameras. Locations in the VTS coordinate system are transformed to the SPECT coordinate system by a VTS/SPECT mapping using a phantom of 7 retro-reflective spheres each filled with a drop of Tc(99m). We switched from pan, tilt and zoom (PTZ) network cameras to fixed network cameras to reduce the amount of camera drift. The improved stability was verified by tracking the positions of fixed retro-reflective markers on a wall. The ability of our VTS to track movement, on average, with sub-millimeter and sub-degree accuracy was established with the 7-sphere phantom for 1 cm vertical and axial steps as well as for an arbitrary rotation and translation. The difference in the time of optical image acquisition as decoded from the image headers relative to synchronization signals sent to the SPECT system was used to establish temporal synchrony between optical and list-mode SPECT acquisition. Two experiments showed better than 100 ms agreement between VTS and SPECT observed motion for three axial translations. We were able to track 3 reflective markers on an anthropomorphic phantom with a precision that allowed us to correct motion such that no loss in visual quality was noted in motion corrected slices relative to motion free slices.

MdmX regulates transformation and chromosomal stability in p53-deficient cells

Zdenka Matijasevic — Thu, 05 Nov 2009 11:35:09 PST

The cellular homologues Mdm2 and MdmX play critical roles in regulating the activity of the p53 tumor suppressor in damaged and non-damaged cells and during development in mice. Recently, we have utilized genetically defined primary cells and mice to reveal that endogenous levels of MdmX can also suppress multipolar mitosis and transformation in hyperploid p53-deficient cells and tumorigenesis in p53-deficient mice. These MdmX functions are not shared by Mdm2, and are distinct from the well-established ability of MdmX to complex with and inhibit p53 activity. Here we discuss some of the ramifications of MdmX loss in p53-deficient cells and mice, and we explore further the fate of MdmX/p53-double null embryonic fibroblasts undergoing multi-polar cell division using time-lapse video microscopy. We also discuss the relationship between chromosomal loss, cell proliferation, and the tumorigenic potential of p53-deficient cells lacking MdmX.

Robust intrapulmonary CD8 T cell responses and protection with an attenuated N1L deleted vaccinia virus

Anuja Mathew — Thu, 05 Nov 2009 11:35:04 PST

BACKGROUND: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the immunogenicity of an attenuated strain of vaccinia virus engineered to inactivate the N1L gene (vGK5). Using the intranasal route, this recombinant virus was 2 logs less virulent compared to the wildtype VACV-WR. Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs. VACV-specific antibodies were also detected in the sera of mice infected 3-5 months prior with the attenuated vGK5 virus. Finally, mice immunized with vGK5 were significantly protected when challenged with a lethal dose of VACV-WR. CONCLUSIONS: These results indicate that the attenuated vGK5 virus protects against subsequent infection and suggest that the N1L protein limits the strength of the early antiviral CD8 T cell response following respiratory infection.

A chromatin assay for human brain tissue

Anouch Matevossian — Thu, 05 Nov 2009 11:34:58 PST

Chronic neuropsychiatric illnesses such as schizophrenia, bipolar disease and autism are thought to result from a combination of genetic and environmental factors that might result in epigenetic alterations of gene expression and other molecular pathology. Traditionally, however, expression studies in postmortem brain were confined to quantification of mRNA or protein. The limitations encountered in postmortem brain research such as variabilities in autolysis time and tissue integrities are also likely to impact any studies of higher order chromatin structures. However, the nucleosomal organization of genomic DNA including DNA:core histone binding - appears to be largely preserved in representative samples provided by various brain banks. Therefore, it is possible to study the methylation pattern and other covalent modifications of the core histones at defined genomic loci in postmortem brain. Here, we present a simplified native chromatin immunoprecipitation (NChIP) protocol for frozen (never-fixed) human brain specimens. Starting with micrococcal nuclease digestion of brain homogenates, NChIP followed by qPCR can be completed within three days. The methodology presented here should be useful to elucidate epigenetic mechanisms of gene expression in normal and diseased human brain.

Neuronal nuclei isolation from human postmortem brain tissue

Anouch Matevossian — Thu, 05 Nov 2009 11:34:53 PST

Neurons in the human brain become postmitotic largely during prenatal development, and thus maintain their nuclei throughout the full lifespan. However, little is known about changes in neuronal chromatin and nuclear organization during the course of development and aging, or in chronic neuropsychiatric disease. However, to date most chromatin and DNA based assays (other than FISH) lack single cell resolution. To this end, the considerable cellular heterogeneity of brain tissue poses a significant limitation, because typically various subpopulations of neurons are intermingled with different types of glia and other non-neuronal cells. One possible solution would be to grow cell-type specific cultures, but most CNS cells, including neurons, are ex vivo sustainable, at best, for only a few weeks and thus would provide an incomplete model for epigenetic mechanisms potentially operating across the full lifespan. Here, we provide a protocol to extract and purify nuclei from frozen (never fixed) human postmortem brain. The method involves extraction of nuclei in hypotonic lysis buffer, followed by ultracentrifugation and immunotagging with anti-NeuN antibody. Labeled neuronal nuclei are then collected separately using fluorescence-activated sorting. This method should be applicable to any brain region in a wide range of species and suitable for chromatin immunoprecipitation studies with site- and modification-specific anti-histone antibodies, and for DNA methylation and other assays.

Genome-scale spatiotemporal analysis of Caenorhabditis elegans microRNA promoter activity

Natalia Julia Martinez — Thu, 05 Nov 2009 11:34:48 PST

The Caenorhabditis elegans genome encodes more than 100 microRNAs (miRNAs). Genetic analyses of miRNA deletion mutants have only provided limited insights into miRNA function. To gain insight into the function of miRNAs, it is important to determine their spatiotemporal expression pattern. Here, we use miRNA promoters driving the expression of GFP as a proxy for miRNA expression. We describe a set of 73 transgenic C. elegans strains, each expressing GFP under the control of a miRNA promoter. Together, these promoters control the expression of 89 miRNAs (66% of all predicted miRNAs). We find that miRNA promoters drive GFP expression in a variety of tissues and that, overall, their activity is similar to that of protein-coding gene promoters. However, miRNAs are expressed later in development, which is consistent with functions after initial body-plan specification. We find that miRNA members belonging to families are more likely to be expressed in overlapping tissues than miRNAs that do not belong to the same family, and provide evidence that intronic miRNAs may be controlled by their own, rather than a host gene promoter. Finally, our data suggest that post-transcriptional mechanisms contribute to differential miRNA expression. The data and strains described here will provide a valuable guide and resource for the functional analysis of C. elegans miRNAs.

Interleukin-4 activates large-conductance, calcium-activated potassium (BKCa) channels in human airway smooth muscle cells

Gilles E. Martin — Thu, 05 Nov 2009 11:34:43 PST

Large-conductance, calcium-activated potassium (BK(Ca)) channels are regulated by voltage and near-membrane calcium concentrations and are determinants of membrane potential and excitability in airway smooth muscle cells. Since the T helper-2 (Th2) cytokine, interleukin (IL)-4, is an important mediator of airway inflammation, we investigated whether IL-4 rapidly regulated BK(Ca) activity in normal airway smooth muscle cells. On-cell voltage clamp recordings were made on subconfluent, cultured human bronchial smooth muscle cells (HBSMC). Interleukin-4 (50 ng ml(-1)), IL-13 (50 ng ml(-1)) or histamine (10 microm) was added to the bath during the recordings. Immunofluorescence studies with selective antibodies against the alpha and beta1 subunits of BK(Ca) were also performed. Both approaches demonstrated that HBSMC membranes contained large-conductance channels (>200 pS) with both calcium and voltage sensitivity, all of which is characteristic of the BK(Ca) channel. Histamine caused a rapid increase in channel activity, as expected. A new finding was that perfusion with IL-4 stimulated rapid, large increases in BK(Ca) channel activity (77.2 +/- 63.3-fold increase, P < 0.05, n = 18). This large potentiation depended on the presence of external calcium. In contrast, IL-13 (50 ng ml(-1)) had little effect on BK(Ca) channel activity, but inhibited the effect of IL-4. Thus, HBSMC contain functional BK(Ca) channels whose activity is rapidly potentiated by the cytokine, IL-4, but not by IL-13. These findings are consistent with a model in which IL-4 rapidly increases near-membrane calcium concentrations to regulate BK(Ca) activity.

Hypercholesterolemia impairs immunity to tuberculosis

Gregory W. Martens — Thu, 05 Nov 2009 11:34:38 PST

We demonstrate that apolipoprotein E -deficient (ApoE(-/-)) mice are highly susceptible to tuberculosis and that their susceptibility depends on the severity of hypercholesterolemia. Wild-type (WT) mice and ApoE(-/-) mice fed a low-cholesterol (LC) or high-cholesterol (HC) diet were infected with approximately 50 CFU Mycobacterium tuberculosis Erdman by aerosol. ApoE(-/-) LC mice were modestly more susceptible to tuberculosis than WT LC mice. In contrast, ApoE(-/-) HC mice were extremely susceptible, as evidenced by 100% mortality after 4 weeks with tuberculosis. The lung pathology of ApoE(-/-) HC mice was remarkable for giant abscess-like lesions, massive infiltration by granulocytes, elevated inflammatory cytokine production, and a mean bacterial load approximately 2 log units higher than that of WT HC mice. Compared to WT HC mice, the gamma interferon response of splenocytes restimulated ex vivo with M. tuberculosis culture filtrate protein was delayed in ApoE(-/-) HC mice, and they failed to control M. tuberculosis growth in the lung. OT-II cells adoptively transferred into uninfected ApoE(-/-) HC mice had a weak proliferative response to their antigen, indicating impaired priming of the adaptive immune response. Our studies show that ApoE(-/-) deficiency is associated with delayed expression of adaptive immunity to tuberculosis caused by defective priming of the adaptive immune response and that elevated serum cholesterol is responsible for this effect.

Idd loci synergize to prolong islet allograft survival induced by costimulation blockade in NOD mice

Julie A. Mangada — Thu, 05 Nov 2009 11:34:33 PST

OBJECTIVE: NOD mice model human type 1 diabetes and are used to investigate tolerance induction protocols for islet transplantation in a setting of autoimmunity. However, costimulation blockade-based tolerance protocols have failed in prolonging islet allograft survival in NOD mice. RESEARCH DESIGN AND METHODS: To investigate the underlying mechanisms, we studied the ability of costimulation blockade to prolong islet allograft survival in congenic NOD mice bearing insulin-dependent diabetes (Idd) loci that reduce the frequency of diabetes. RESULTS: The frequency of diabetes is reduced in NOD.B6 Idd3 mice and is virtually absent in NOD.B6/B10 Idd3 Idd5 mice. Islet allograft survival in NOD.B6 Idd3 mice treated with costimulation blockade is prolonged compared with NOD mice, and in NOD.B6/B10 Idd3 Idd5, mice islet allograft survival is similar to that achieved in C57BL/6 mice. Conversely, some Idd loci were not beneficial for the induction of transplantation tolerance. Alloreactive CD8 T-cell depletion in (NOD x CBA)F1 mice treated with costimulation blockade was impaired compared with similarly treated (C57BL/6.H2(g7) x CBA)F1 mice. Injection of exogenous interleukin (IL)-2 into NOD mice treated with costimulation prolonged islet allograft survival. NOD.B6 Idd3 mice treated with costimulation blockade deleted alloreactive CD8 T-cells and exhibited prolonged islet allograft survival. CONCLUSIONS: Il2 is the Idd3 diabetes susceptibility gene and can influence the outcome of T-cell deletion and islet allograft survival in mice treated with costimulation blockade. These data suggest that Idd loci can facilitate induction of transplantation tolerance by costimulation blockade and that IL-2/Idd3 is a critical component in this process.

Engineered intermonomeric disulfide bonds in the globular domain of Newcastle disease virus hemagglutinin-neuraminidase protein: implications for the mechanism of fusion promotion

Paul J. Mahon — Thu, 05 Nov 2009 11:34:28 PST

The promotion of membrane fusion by Newcastle disease virus (NDV) requires an interaction between the viral hemagglutinin-neuraminidase (HN) and fusion (F) proteins, although the mechanism by which this interaction regulates fusion is not clear. The NDV HN protein exists as a tetramer composed of a pair of dimers. Based on X-ray crystallographic studies of the NDV HN globular domain (S. Crennell et al., Nat. Struct. Biol. 7:1068-1074, 2000), it was proposed that the protein undergoes a significant conformational change from an initial structure having minimal intermonomeric contacts to a structure with a much more extensive dimer interface. This conformational change was predicted to be integral to fusion promotion with the minimal interface form required to maintain F in its prefusion state until HN binds receptors. However, no evidence for such a conformational change exists for any other paramyxovirus attachment protein. To test the NDV model, we have engineered a pair of intermonomeric disulfide bonds across the dimer interface in the globular domain of an otherwise non-disulfide-linked NDV HN protein by the introduction of cysteine substitutions for residues T216 and D230. The disulfide-linked dimer is formed both intracellularly and in the absence of receptor binding and is efficiently expressed at the cell surface. The disulfide bonds preclude formation of the minimal interface form of the protein and yet enhance both receptor-binding activity at 37 degrees C and fusion promotion. These results confirm that neither the minimal interface form of HN nor the proposed drastic conformational change in the protein is required for fusion.

A randomized clinical trial comparing low-glycemic index versus ADA dietary education among individuals with type 2 diabetes

Yunsheng Ma — Thu, 05 Nov 2009 11:34:22 PST

OBJECTIVE: We compared the effects of a low glycemic index (GI) diet with the American Diabetes Association (ADA) diet on glycosylated hemoglobin (HbA1c) among individuals with type 2 diabetes. METHODS: Forty individuals with poorly controlled type 2 diabetes were randomized to a low-GI or an ADA diet. The intervention, consisting of eight educational sessions (monthly for the first 6 mo and then at months 8 and 10), focused on a low-GI or an ADA diet. Data on demographics, diet, physical activity, psychosocial factors, and diabetes medication use were assessed at baseline and 6 and 12 mo. Generalized linear mixed models were used to compare the two groups on HbA1c, diabetic medication use, blood lipids, weight, diet, and physical activity. RESULTS: Participants (53% female, mean age 53.5 y) were predominantly white with a mean body mass index of 35.8 kg/m(2). Although both interventions achieved similar reductions in mean HbA1c at 6 mo and 12 mo, the low-GI diet group was less likely to add or increase dosage of diabetic medications (odds ratio 0.26, P = 0.01). Improvements in high-density lipoprotein cholesterol, triacylglycerols, and weight loss were similar between groups. CONCLUSION: Compared with the ADA diet, the low-GI diet achieved equivalent control of HbA1c using less diabetic medication. Despite its limited size, this trial suggests that a low-GI diet is a viable alternative to the ADA diet. Findings should be evaluated in a larger randomized controlled trial.

Dietary quality 1 year after diagnosis of coronary heart disease

Yunsheng Ma — Thu, 05 Nov 2009 11:34:17 PST

OBJECTIVE: The purpose of this ancillary study is to determine the quality of diets in patients with documented coronary heart disease (CHD). DESIGN: Dietary data were originally collected using a 24-hour dietary recall in 555 patients with CHD, 1 year after a diagnostic coronary angiography. Data used for this investigation were collected between March 2001 and November 2003. SUBJECTS/SETTING: Patients were participants in a clinical trial to improve adherence to lipid-lowering medications. The Alternate Healthy Eating Index, an instrument designed to evaluate the degree to which a diet has the potential to prevent cardiovascular disease, measured dietary quality. MAIN OUTCOME MEASURES: Linear regression models were used to assess the association of dietary quality with patients' sociodemographic and clinical characteristics. RESULTS: Mean age of participants was 61 years, with an average body mass index of 30 (calculated as kg/m(2)). Sixty percent were men. Average daily caloric intake was 1,775 kcal, with 50% of calories derived from carbohydrates, 18% from protein, and 32% from total fat. Average Alternate Healthy Eating Index score was 30.8 out of a possible maximum score of 80. Only 12.4% of subjects met the recommended consumption of vegetables, 7.8% for fruit, 8% for cereal fiber, and 5.2% for trans-fat intake. Lower dietary quality was associated with lower total caloric intake, as well as with smoking, obesity, and lower educational level. CONCLUSIONS: A high proportion of patients reported poor dietary quality 1 year after experiencing a coronary event. Our data support continued efforts to enhance healthful dietary changes over time for secondary prevention of CHD. Dietary change should be emphasized with CHD patients who are less educated, smokers, or obese.

Association between dietary fiber and markers of systemic inflammation in the Women's Health Initiative Observational Study

Yunsheng Ma — Thu, 05 Nov 2009 11:34:12 PST

OBJECTIVE: Systemic inflammation may play an important role in the development of atherosclerosis, type 2 diabetes, and some cancers. Few studies have comprehensively assessed the direct relations between dietary fiber and inflammatory cytokines, especially in minority populations. Using baseline data from 1958 postmenopausal women enrolled in the Women's Health Initiative Observational Study, we examined cross-sectional associations between dietary fiber intake and markers of systemic inflammation (including serum high-sensitivity C-reactive protein [hs-CRP], interleukin-6 [IL-6], and tumor necrosis factor-alpha receptor-2 [TNF-alpha-R2]) in addition to differences in these associations by ethnicity. METHODS: Multiple linear regression models were used to assess the relation between fiber intake and makers of systemic inflammation. RESULTS: After adjustment for covariates, intakes of dietary fiber were inversely associated with IL-6 (P values for trend were 0.01 for total fiber, 0.004 for soluble fiber, and 0.001 for insoluble fiber) and TNF-alpha-R2 (P values for trend were 0.002 for total, 0.02 for soluble, and <0.001 for insoluble fibers). Although the samples were small in minority Americans, results were generally consistent with those found among European Americans. We did not observe any significant association between intake of dietary fiber and hs-CRP. CONCLUSION: These findings lend support to the hypothesis that a high-fiber diet is associated with lower plasma levels of IL-6 and TNF-alpha-R2. Contrary to previous reports, however, there was no association between fiber and hs-CRP among postmenopausal women. Future studies on the influence of diet on inflammation should include IL-6 and TNF-alpha-R2 and enroll participants from ethnic minorities.

Nucleophosmin is a binding partner of nucleostemin in human osteosarcoma cells

Hanhui Ma — Thu, 05 Nov 2009 11:34:07 PST

Nucleostemin (NS) is expressed in the nucleoli of adult and embryonic stem cells and in many tumors and tumor-derived cell lines. In coimmunoprecipitation experiments, nucleostemin is recovered with the tumor suppressor p53, and more recently we have demonstrated that nucleostemin exerts its role in cell cycle progression via a p53-dependent pathway. Here, we report that in human osteosarcoma cells, nucleostemin interacts with nucleophosmin, a nucleolar protein believed to possess oncogenic potential. Nucleostemin (NS) and nucleophosmin (NPM) displayed an extremely high degree of colocalization in the granular component of the nucleolus during interphase, and both proteins associated with prenucleolar bodies in late mitosis before the reformation of nucleoli. Coimmunoprecipitation experiments revealed that NS and NPM co-reside in complexes, and yeast two-hybrid experiments confirmed that they are interactive proteins, revealing the NPM-interactive region to be the 46-amino acid N-terminal domain of NS. In bimolecular fluorescence complementation studies, bright nucleolar signals were observed, indicating that these two proteins directly interact in the nucleolus in vivo. These results support the notion that cell cycle regulatory proteins congress and interact in the nucleolus, adding to the emerging concept that this nuclear domain has functions beyond ribosome production.

Analysis of integrin beta4 expression in human breast cancer: association with basal-like tumors and prognostic significance

Shaolei Lu — Thu, 05 Nov 2009 11:34:02 PST

PURPOSE: The beta4 integrin has been implicated in functions associated with the genesis and progression of carcinomas based on data obtained from cell lines and mouse models. Data on its expression and relevance to human carcinomas, however, are relatively scant. The aim of this study was to assess its expression and prognostic significance in human breast carcinomas. EXPERIMENTAL DESIGN: We integrated data on beta4 expression from multiple gene profiling studies of breast tumors of known clinical outcome with immunohistochemical analysis of 105 breast carcinomas, and we identified genes whose expression correlates with that of beta4. RESULTS: The expression of both beta4 mRNA and protein is not homogeneous in breast cancer and it associates most significantly with the "basal-like" subtype of breast tumors (P = 0.008). No association between beta4 and HER2 expression was evident from either gene profiling or immunohistochemical analysis. To gain insight into the relevance of beta4 expression to human breast carcinomas, we generated a 65-gene "beta4 signature" based on integration of four published gene profiling studies that included the top 0.1% of genes that correlated with beta4, either positively or negatively. This beta4 signature predicted decreased time to tumor recurrence and survival of patients when applied to four data sets including two independent ones. CONCLUSIONS: These observations indicate that beta4 expression in human breast cancer is restricted and associated with basal-like cancers, and they support the hypothesis that beta4 may function in concert with a discrete set of proteins to facilitate the aggressive behavior of a subset of tumors.

Linking SNPs to CAG repeat length in Huntington's disease patients

Wanzhao Liu — Thu, 05 Nov 2009 11:33:57 PST

Allele-specific silencing using small interfering RNAs targeting heterozygous single-nucleotide polymorphisms (SNPs) is a promising therapy for human trinucleotide repeat diseases such as Huntington's disease. Linking SNP identities to the two HTT alleles, normal and disease-causing, is a prerequisite for allele-specific RNA interference. Here we describe a method, SNP linkage by circularization (SLiC), to identify linkage between CAG repeat length and nucleotide identity of heterozygous SNPs using Huntington's disease patient peripheral blood samples.

An experimental and theoretical evaluation of the influence of pretargeting antibody on the tumor accumulation of effector

Guozheng Liu — Thu, 05 Nov 2009 11:33:51 PST

In treating tumors by pretargeting, the antitumor antibody and the cytotoxic effector (e.g., toxins and radioactivity) are separately administered. Therefore, pretargeting is more complicated with many variables. We are conducting studies to understand the influence of each variable using a novel recognition pair of mutually complementary phosphorodiamidate morpholino oligomers (MORF/cMORF). Earlier we developed a semi-empirical model capable of accurately predicting the behavior of a radiolabeled cMORF effector with variations in dosages and timing. We have now extended the model to predict the effector behavior, in particular, its maximum percent tumor accumulation (MPTA) in mice pretargeted with three different MORF-conjugated antibodies (MN14, B72.3, and CC49). The MN14 and the CC49 target different antigens in the same tumor, whereas the CC49 and the B72.3 target the same antigen but with very different tumor accumulation. By comparing the pretargeting results of these three antibodies with our prediction, we confirmed that the MPTA of the radiolabeled cMORF effector in the LS174T tumor is independent of the antibodies. In conclusion, the MPTA cannot be improved through the use of different pretargeting antibodies, although different antibodies may improve the maximum absolute tumor accumulation, the heterogeneity, and/or the tumor-to-normal tissue ratios of the effector. This conclusion will apply equally well to effectors carrying a fluorescent probe, an anticancer agent, or a radioactive imaging agent.

BRCA-FA pathway as a target for anti-tumor drugs

Rachel Litman — Thu, 05 Nov 2009 11:33:46 PST

Promising research on DNA repair signaling pathways predicts a new age of anti-tumor drugs. This research was initiated through the discovery and characterization of proteins that functioned together in signaling pathways to sense, respond, and repair DNA damage. It was realized that tumor cells often lacked distinct DNA repair pathways, but simultaneously relied heavily on compensating pathways. More recently, researchers have begun to manipulate these compensating pathways to reign in and kill tumor cells. In a striking example it was shown that tumors derived from mutations in the DNA repair genes, of BRCA-FA pathway, were selectively sensitive to inhibition of the base excision repair pathway. These findings suggest that tumors derived from defects in DNA repair genes will be easier to treat clinically, providing a streamlined and targeted therapy that spares healthy cells. In the future, identifying patients with susceptible tumors and discovering additional DNA repair targets amenable to anti-tumor drugs will have a major impact on the course of cancer treatment.

Apolipoprotein D in CD34-positive and CD34-negative cutaneous neoplasms: a useful marker in differentiating superficial acral fibromyxoma from dermatofibrosarcoma protuberans

Mikhail Lisovsky — Thu, 05 Nov 2009 11:33:41 PST

More recent techniques to characterize the genetic profile of soft-tissue tumors include the use of gene arrays. Using this technique, Apolipoprotein D (Apo D), a 33-kDa glycoprotein component of high-density lipoprotein, has been found to be highly expressed in dermatofibrosarcoma protuberans. To corroborate these results, we sought to ascertain the utility of Apo D by investigating its sensitivity and specificity in a variety of CD34-positive and CD34-negative cutaneous neoplasms including superficial acral fibromyxoma, sclerotic fibromas, and cellular dermatofibromas. Of interest, we found absence of Apo D expression in all four cases of superficial acral fibromyxoma. Of the remaining CD34-positive lesions, Apo D expression was noted in 35/36 (97%) cases of dermatofibrosarcoma protuberans, 3/5 (60%) giant-cell fibroblastomas, 4/4 (100%) sclerotic fibromas, 8/8 (100%) neurofibromas, and 1/1 (100%) solitary fibrous tumor. Of the CD34-negative lesions, Apo D expression was noted in 2/22 (9%) regular dermatofibroma, 23/45 (51%) cellular dermatofibroma, 10/10 (100%) malignant fibrous histiocytoma, 9/10 (90%) atypical fibroxanthoma, 7/8 (86%) cellular neurothekeoma, 9/9 (100%) malignant melanoma, 8/8 (100%) melanocytic nevi (100%), 0/2 superficial angiomyxoma, 0/15 fibromatosis, 0/1 nodular fasciitis, and 1/2 (50%) desmoplastic fibroblastomas. In summary, our findings indicate that Apo D expression is not specific to dermatofibrosarcoma protuberans. Its principal use as an immunohistochemical adjunct lies in its utility in differentiating superficial acral fibromyxoma from dermatofibrosarcoma protuberans. Although strong positive staining of Apo D in a markedly atypical fibrohistiocytic lesion is suggestive of atypical fibroxanthoma and/or malignant fibrous histiocytoma, further studies with the inclusion of other atypical spindled cell neoplasms are required to conclusively prove the same.

A NOVEL METHOD FOR TEACHING THE FIRST INSTANCES OF SIMPLE DISCRIMINATION TO NONVERBAL CHILDREN WITH AUTISM IN A LABORATORY ENVIRONMENT

Karen M. Lionello-Denolf — Thu, 05 Nov 2009 11:33:37 PST

A novel method for initiating discrimination training with nonverbal children combines a delayed S+ procedure that requires children to refrain from responding to either of 2 physically different choice stimuli until a prompt stimulus is added onto 1 of the choices, and a delayed prompting procedure that presents the same 2-choice stimulus display, but stimuli are initially added onto both choices. After a short delay, the added stimulus on the S- is removed, and the choice of the S+ is thus prompted. If the children learn to observe and respond to the defining features of the S+ choice stimulus, then they may respond to the S+ prior to the added-stimulus removal. Implementation was successful with 8 nonverbal children who had not previously exhibited simple simultaneous discrimination, suggesting a useful methodology for initiating discrimination training with populations for whom verbal instruction is ineffective.

Effect of adenosine A2 receptor stimulation on platelet activation-aggregation: differences between canine and human models

Matthew D. Linden — Thu, 05 Nov 2009 11:33:31 PST

INTRODUCTION: Adenosine A(2) agonists improve arterial patency in experimental models of recurrent thrombosis, an effect purportedly triggered by stimulation of platelet A(2) receptors and subsequent down-regulation of platelet function. However: (i) there is no direct evidence to substantiate this premise; and (ii) given the recognized differences among species in platelet signaling, it is possible that the mechanisms of A(2) receptor stimulation may be model-dependent. Accordingly, we applied an integrated in vivo and in vitro approach, using both canine and human models, to test the hypothesis that the anti-thrombotic effects of A(2) agonist treatment are due in part to inhibition of platelet activation. METHODS: In Protocol 1, recurrent coronary thrombosis was triggered in anesthetized dogs by application of a stenosis at a site of arterial injury. Coronary patency and flow cytometric indices of platelet activation (P-selectin expression; formation of heterotypic aggregates) were compared in dogs pre-treated with the A(2) agonist CGS 21680 versus controls. In Protocols 2 and 3, blood samples were obtained from dogs and human volunteers. In vitro aggregation and platelet activation (assessed by impedance aggregometry and flow cytometry, respectively) were quantified in paired aliquots pre-incubated with CGS versus vehicle. RESULTS: In the canine models, CGS improved in vivo coronary patency and attenuated in vitro aggregation but, contrary to our hypothesis, did not evoke a down-regulation in platelet activation. In contrast, in human blood samples, CGS attenuated both in vitro aggregation and flow cytometric markers of platelet activation-aggregation. CONCLUSION: The mechanisms contributing to the anti-thrombotic effect of A(2) agonist treatment are species-dependent: adenosine A(2) receptor stimulation inhibits platelet activation in human, but not canine, models.

Immune system derived from homeostatic proliferation generates normal CD8 T-cell memory but altered repertoires and diminished heterologous immune responses

Sue-Jane Lin — Thu, 05 Nov 2009 11:33:27 PST

The host responds to lymphopenic environments by acute homeostatic proliferation of T lymphocytes, which acquire phenotypes similar to memory cells. Using T-cell knockout (KO) mice adoptively reconstituted with splenocytes from immunologically naive mice, we examined the immune responses of an immune system derived from homeostatically proliferating (HP) T cells. HP cells mounted relatively normal acute CD8 T-cell responses to lymphocytic choriomeningitis virus (LCMV), but with altered T-cell receptor (TCR) repertoires, and they became functional memory cells capable of recall responses. Although homeostatic proliferation does not normally fully restore T-cell numbers, the CD8(+) T-cell pool was completely restored in T-cell KO mice after LCMV infection. CD4 T-cell responses were lower and not fully restored but seemed sufficient to allow for complete differentiation of CD8 memory T cells. The LCMV-immune HP mouse had an immune repertoire heavily biased with LCMV epitope-specific T cells with oligoclonal expansions. LCMV-immune HP mice had reduced cross-reactive and non-cross-reactive CD8 T-cell responses when challenged with a T cell-cross-reactive virus. Thus, whereas an HP immune system is capable of mounting relatively normal acute and memory CD8 T-cell responses, the narrowing of the T-cell repertoire may reduce immune responses to subsequently encountered pathogens.

The globular tail domain puts on the brake to stop the ATPase cycle of myosin Va

Xiang-Dong Li — Thu, 05 Nov 2009 11:33:22 PST

Myosin Va is a well known processive motor involved in transport of organelles. A tail-inhibition model is generally accepted for the regulation of myosin Va: inhibited myosin Va is in a folded conformation such that the tail domain interacts with and inhibits myosin Va motor activity. Recent studies indicate that it is the C-terminal globular tail domain (GTD) that directly inhibits the motor activity of myosin Va. In the present study, we identified a conserved acidic residue in the motor domain (Asp-136) and two conserved basic residues in the GTD (Lys-1706 and Lys-1779) as critical residues for this regulation. Alanine mutations of these conserved charged residues not only abolished the inhibition of motor activity by the GTD but also prevented myosin Va from forming a folded conformation. We propose that Asp-136 forms ionic interactions with Lys-1706 and Lys-1779. This assignment locates the GTD-binding site in a pocket of the motor domain, formed by the N-terminal domain, converter, and the calmodulin in the first IQ motif. We propose that binding of the GTD to the motor domain prevents the movement of the converter/lever arm during ATP hydrolysis cycle, thus inhibiting the chemical cycle of the motor domain.

Arthroscopic debridement of the osteoarthritic knee combined with hyaluronic acid (Orthovisc(R)) treatment: A case series and review of the literature

Xinning Li — Thu, 05 Nov 2009 11:33:16 PST

ABSTRACT: OBJECTIVE: An evaluation of safety and efficacy of high molecular weight hyaluronan (HA) delivered at the time of arthroscopic debridement of the osteoarthritic knee. METHODS: Thirty consecutive patients who met inclusion and exclusion criteria underwent arthroscopic debridement by a single surgeon and concomitant delivery of 6 ml/90 mg HA (Orthovisc(R)). These patients were evaluated preoperatively, at 6 weeks, 3 and 6 months post-operatively. Evaluations consisted of WOMAC pain score, SF-36 Physical Component Summary (PCS) score and complications. RESULTS: No complications occurred during this study. Pre-op average WOMAC pain score was 6.8 +/- 3.5 (n = 30) with a reduction to 3.4 +/- 3.1 at 6 weeks (n = 27). Final average WOMAC pain score improved to 3.2 +/- 3.8 at six months (n = 23). No patients had deterioration of the WOMAC pain score. Mean pre-operative SF-36 PCS score was 39.0 +/- 10.4 with SF-36 PCS score of the bottom 25th percentile at 29.9 (n = 30). Post procedure and HA delivery, mean PCS score at 6 weeks improved to 43.7 +/- 8.0 with the bottom 25th percentile at 37.5 (n = 27). At 6 months, mean PCS score was 48.0 +/- 9.8 with the bottom 25th percentile improved to 45.8 (n = 23). CONCLUSION: The results show that concomitant delivery of high molecular weight hyaluronan (Orthovisc(R) - 6 ml/90 mg) is safe when given at the time of arthroscopic debridement of the osteoarthritic knee. By delivering HA (Orthovisc(R)) at the time of the arthroscopic debridement, there may be a decreased risk of joint infection and/or injection site pain. Furthermore, the combination of both procedures show efficacy in reducing WOMAC pain scores and improving SF-36 PCS scores over a six month period.

Should adjustment for covariates be used in prevalence estimations

Wenjun Li — Thu, 05 Nov 2009 11:33:11 PST

ABSTRACT: BACKGROUND: Adjustment for covariates (also called auxiliary variables in survey sampling literature) is commonly applied in health surveys to reduce the variances of the prevalence estimators. In theory, adjusted prevalence estimators are more accurate when variance components are known. In practice, variance components needed to achieve the adjustment are unknown and their sample estimators are used instead. The uncertainty introduced by estimating variance components may overshadow the reduction in the variance of the prevalence estimators due to adjustment. We present empirical guidelines indicating when adjusted prevalence estimators should be considered, using gender adjusted and unadjusted smoking prevalence as an illustration. METHODS: We compare the accuracy of adjusted and unadjusted prevalence estimators via simulation. We simulate simple random samples from hypothetical populations with the proportion of males ranging from 30% to 70%, the smoking prevalence ranging from 15% to 35%, and the ratio of male to female smoking prevalence ranging from 1 to 4. The ranges of gender proportions and smoking prevalences reflect the conditions in 1999-2003 Behavioral Risk Factors Surveillance System (BRFSS) data for Massachusetts. From each population, 10,000 samples are selected and the ratios of the variance of the adjusted prevalence estimators to the variance of the unadjusted (crude) ones are computed and plotted against the proportion of males by population prevalence, as well as by population and sample sizes. The prevalence ratio thresholds, above which adjusted prevalence estimators have smaller variances, are determined graphically. RESULTS: In many practical settings, gender adjustment results in less accuracy. Whether or not there is better accuracy with adjustment depends on sample sizes, gender proportions and ratios between male and female prevalences. In populations with equal number of males and females and smoking prevalence of 20%, the adjusted prevalence estimators are more accurate when the ratios of male to female prevalences are above 2.4, 1.8, 1.6, 1.4 and 1.3 for sample sizes of 25, 50, 100, 150 and 200, respectively. CONCLUSION: Adjustment for covariates will not result in more accurate prevalence estimator when ratio of male to female prevalences is close to one, sample size is small and risk factor prevalence is low. For example, when reporting smoking prevalence based on simple random sampling, gender adjustment is recommended only when sample size is greater than 200.

Fas Ag-FasL coupling leads to ERK1/2-mediated proliferation of gastric mucosal cells

Hanchen Li — Thu, 05 Nov 2009 11:33:06 PST

When cells within the gastric mucosa progress from metaplasia to dysplasia to cancer, they acquire a Fas Ag apoptosis-resistant phenotype. It is unusual to completely abolish the pathway, suggesting other forms of Fas Ag signaling may be important or even necessary for gastric cancer to progress. Little is known about alternate signaling of the Fas Ag pathway in gastric mucosal cells. Using a cell culture model of rat gastric mucosal cells, we show that gastric mucosal cells utilize a type II signaling pathway for apoptosis. Under conditions of low receptor stimulation or under conditions where apoptosis is blocked downstream of the death-inducing signal complex, Fas Ag signaling proceeds toward proliferative signaling. Under conditions favoring proliferative signaling, cFLIP is recruited to the Fas-associated death domain-like interleukin-1beta-converting enzyme at the death-inducing signal complex and activates ERK1/2. ERK1/2 in turn activates NF-kappaB. ERK1/2 stimulates proliferation, whereas NF-kappaB activation results in upregulation of the antiapoptotic protein survivin, further promoting proliferation over apoptosis. These results suggest that factors that inhibit apoptosis confer a growth advantage to the cells beyond the survival advantage of avoiding apoptosis and in effect convert the Fas Ag signaling pathway from a tumor suppressor to a tumor promoter.

Fournier gangrene: role of imaging

Robin B. Levenson — Thu, 05 Nov 2009 11:33:01 PST

Fournier gangrene is a rapidly progressing necrotizing fasciitis involving the perineal, perianal, or genital regions and constitutes a true surgical emergency with a potentially high mortality rate. Although the diagnosis of Fournier gangrene is often made clinically, emergency computed tomography (CT) can lead to early diagnosis with accurate assessment of disease extent. CT not only helps evaluate the perineal structures that can become involved by Fournier gangrene, but also helps assess the retroperitoneum, to which the disease can spread. Findings at CT include asymmetric fascial thickening, subcutaneous emphysema, fluid collections, and abscess formation. Subcutaneous emphysema is the hallmark of Fournier gangrene but is not seen in all cases. Compared with radiography and ultrasonography, CT provides a higher specificity for the diagnosis of Fournier gangrene and superior evaluation of disease extent; however, diagnosis and evaluation can also be performed with these other modalities. The administration of broad-spectrum antibiotics and aggressive surgical debridement of the nonviable tissue are both essential for successful treatment. An awareness of the CT features of Fournier gangrene is imperative for prompt diagnosis and effective treatment planning.

Non-genomic actions of thyroid hormone in brain development

Jack L. Leonard — Thu, 05 Nov 2009 11:32:56 PST

Thyroid hormone (TH) is essential for neuronal migration and synaptogenesis in the developing brain. Assembly of neuronal circuits depends on guidance cues provided by the extracellular matrix. These cues are interpreted by the migrating neuron and its growing neurites through transmembrane signaling proteins anchored in place by the actin cytoskeleton. One of the best examples of a non-genomic action of thyroid hormone is its dynamic regulation of the number and quantity of actin fibers in astrocytes. Thyroxine (T4) and its transcriptionally inactive metabolite, 3',5',3-triiodothyronine (reverse T3) are responsible for modulating microfilament organization, while the transcriptional activator, 3',3,5-triiodothyronine (T3) is inert. The biological consequence of the loss of the actin filaments in astrocytes is the inability of the cell to anchor laminin, to its cell surface, and the loss of this key guidance molecule interrupts neurite pathfinding and neuronal migration. These data provide the essentials to construct a physiological pathway where TH-dependent regulation of the polymerization state of actin in the astrocyte and the developing neuron modulates the production and recognition of guidance cues--cues that if disrupted lead to abnormal neuronal migration and neuronal process formation--and lead to the morphological deficits observed in the cretinous brain.

Sorting of EGF and transferrin at the plasma membrane and by cargo-specific signaling to EEA1-enriched endosomes

Deborah Leonard — Thu, 05 Nov 2009 11:32:51 PST

The biological function of receptors is determined by their appropriate trafficking through the endosomal pathway. Following internalization, the transferrin (Tf) receptor quantitatively recycles to the plasma membrane, whereas the epidermal growth factor (EGF) receptor undergoes degradation. To determine how Tf and EGF engage these two different pathways we imaged their binding and early endocytic pathway in live cells using total internal reflection fluorescence microscopy (TIRF-M). We find that EGF and Tf bind to distinct plasma membrane regions and are incorporated into different endocytic vesicles. After internalization, both EGF-enriched and Tf-enriched vesicles interact with endosomes containing early endosome antigen 1 (EEA1). EGF is incorporated and retained in these endosomes, while Tf-containing vesicles rapidly dissociate and move to a juxtanuclear compartment. Endocytic vesicles carrying EGF recruit more Rab5 GTPase than those carrying Tf, which, by strengthening their association with EEA1-enriched endosomes, may provide a mechanism for the observed cargo-specific sorting. These results reveal pre-endocytic sorting of Tf and EGF, a specialized role for EEA1-enriched endosomes in EGF trafficking, and a potential mechanism for cargo-specified sorting of endocytic vesicles by these endosomes.

A functional Notch-survivin gene signature in basal breast cancer

Connie Wing-Ching Lee — Thu, 05 Nov 2009 11:32:46 PST

INTRODUCTION: Basal-type, or triple-negative, breast cancer (lacking estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 expression) is a high-risk disease for which no molecular therapies are currently available. We studied genetic signatures of basal breast cancer potentially suitable for therapeutic intervention. METHODS: We analyzed protein expression of the Notch-1 intracellular domain and survivin by immunohistochemistry in a series of basal breast cancer patients. A hierarchical clustering and overall survival analysis was carried out on a microarray mRNA database of 232 breast cancer patients. Fifteen published mRNA datasets containing estrogen receptor-negative or estrogen receptor-positive samples were subjected to meta-analysis for co-segregated gene expression. Experiments of plasmid transfection and gene silencing were carried out in estrogen receptor-negative MDA-MB-231 breast cancer cells. RESULTS: The developmental signaling regulator Notch-1 was highly expressed in breast cancer, compared with normal tissue, and was segregated with basal disease. Higher Notch-1 levels correlated with progressively abbreviated overall survival, and with increased expression of survivin, a tumor-associated cell death and mitotic regulator implicated in stem cell viability. Analysis of Pearson's correlation coefficient indicated that Notch-1 and survivin co-segregated in basal breast cancer. Notch-1 stimulation in MDA-MB-231 cells increased survivin expression, whereas silencing Notch reduced survivin levels. CONCLUSIONS: A Notch-1-survivin functional gene signature is a hallmark of basal breast cancer, and may contribute to disease pathogenesis. Antagonists of Notch and survivin currently in the clinic may be tested as novel molecular therapy for these recurrence-prone patients.

Molecular dependence of estrogen receptor-negative breast cancer on a notch-survivin signaling axis

Connie Wing-Ching Lee — Thu, 05 Nov 2009 11:32:41 PST

Despite progress in the management of breast cancer, the molecular underpinnings of clinically aggressive subtypes of the disease are not well-understood. Here, we show that activation of Notch developmental signaling in estrogen receptor (ER)-negative breast cancer cells results in direct transcriptional up-regulation of the apoptosis inhibitor and cell cycle regulator survivin. This response is associated with increased expression of survivin at mitosis, enhanced cell proliferation, and heightened viability at cell division. Conversely, targeting Notch signaling with a peptidyl gamma-secretase inhibitor suppressed survivin levels, induced apoptosis, abolished colony formation in soft agar, and inhibited localized and metastatic tumor growth in mice, without organ or systemic toxicity. In contrast, ER+ breast cancer cells, or various normal cell types, were insensitive to Notch stimulation. Therefore, ER- breast cancer cells become dependent on Notch-survivin signaling for their maintenance, in vivo. Therapeutic targeting of this pathway may be explored for individualized treatment of patients with clinically aggressive, ER- breast cancer.

Cbfbeta-SMMHC impairs differentiation of common lymphoid progenitors and reveals an essential role for RUNX in early B-cell development

Ya-Huei Kuo — Thu, 05 Nov 2009 11:32:36 PST

The core-binding factor (CBF)-associated leukemia fusion protein CBFbeta-SMMHC impairs myeloid and lymphoid differentiation. By inhibiting RUNX function, the fusion oncoprotein predisposes specifically to acute myeloid leukemia in both patients and mouse models. We have shown that Cbfbeta-SMMHC expression leads to a sustained reduction of circulating B lymphocytes in the mouse. In this study, we demonstrate that the activation of Cbfbeta-SMMHC reduces pre-pro-B cells approximately 3-fold and pre-B cells more than 10-fold and that this differentiation block is cell-autonomous. The reduction of pre-pro-B cells coincided with an increase in apoptosis in this population. The number of common lymphoid progenitors (CLPs) were not affected; however, the expression of critical early B-cell factors Ebf1, Tcfe2a, and Pax5 was significantly reduced. In addition, Cbfbeta-SMMHC reduced Rag1 and Rag2 expression and impaired V(D)J recombination in the CLPs. Furthermore, CLPs expressing Cbfbeta-SMMHC also show inhibition of B cell-specific genes Cd79a, Igll1, VpreB1, and Blk. These results demonstrate that CBF/RUNX function is essential for the function of CLPs, the survival of pre-pro-B cells, and the establishment of a B lineage-specific transcriptional program. This study also provides a mechanistic basis for the myeloid-lineage bias of CBFbeta-SMMHC-associated leukemia.

Binding of ATP to UAP56 is necessary for mRNA export

Krishna P. Kota — Thu, 05 Nov 2009 11:32:31 PST

The major-histocompatibility-complex protein UAP56 (BAT1) is a DEAD-box helicase that is deposited on mRNA during splicing. UAP56 is retained on spliced mRNA in an exon junction complex (EJC) or, alternatively, with the TREX complex at the 5' end, where it might facilitate the export of the spliced mRNA to the cytoplasm. Using confocal microscopy, UAP56 was found to be concentrated in RNA-splicing speckled domains of nuclei but was also enriched in adjacent nuclear regions, sites at which most mRNA transcription and splicing occur. At speckled domains, UAP56 was in complexes with the RNA-splicing and -export protein SRm160, and, as measured by FRAP, was in a dynamic binding equilibrium. The application of an in vitro FRAP assay, in which fluorescent nuclear proteins are photobleached in digitonin-extracted cells, revealed that the equilibrium binding of UAP56 in complexes at speckled domains was directly regulated by ATP binding. This was confirmed using a point mutant of UAP56 that did not bind ATP. Point mutation of UAP56 to eliminate ATP binding did not affect RNA splicing, but strongly inhibited the export of mRNA to the cytoplasm.

The effects of Tween-80 on the integrity of solutions of capsaicin: useful information for performing tussigenic challenges

Scott E. Kopec — Thu, 05 Nov 2009 11:32:26 PST

ABSTRACT: BACKGROUND: Because variable results of capsaicin challenges may be due to the incomplete solubility of capsaicin, we sought to determine if the use of Tween-80 in solutions of capsaicin improves actual concentrations of freshly prepared and stored solutions. METHODS: Capsaicin solutions ranging from 0.5-128 muM were mixed with and without Tween-80. Samples of various concentrations were then stored under 4 environmental conditions: 4 degrees C, protected from light; room temperature, protected from light; room temperature, exposed to light; -20 degrees C. All samples were analyzed initially, and at 2 and 4 months. RESULTS: While freshly prepared solutions with Tween-80 had consistently higher concentrations than those prepared without Tween-80 (83% vs. 69%), Tween-80 does not facilitate complete solubility. For solutions stored at 4 degrees C and protected from light, there was a significant decrease after 2 months in low concentration solutions of both the Tween-80 and non-Tween-80 solutions. Both Tween-80 and non-Tween-80 containing solutions significantly decreased in concentration after 2 months when stored at room temperature and protected from light, room temperature and exposed to light, and -20 degrees C. Concentrations of solutions made of 4 muM or higher are stable when stored at 4 degrees C and protected from light for 4 months. CONCLUSION: While the inherent difficulty of forcing capsaicin into solution cannot be eliminated, it can be improved with Tween-80. However, the addition of Tween-80 does not prevent the breakdown of stored capsaicin solutions. We recommend preparing and storing capsaicin solutions according to the methods and results of this study.

The safety and tolerability of an HIV-1 DNA prime-protein boost vaccine (DP6-001) in healthy adult volunteers

Jeffrey S. Kennedy — Thu, 05 Nov 2009 11:32:21 PST

This report describes the safety observations following administration of a polyvalent DNA prime-protein boost HIV-1 vaccine formulated with adjuvant QS21. Local injection site reactions were the most common (65% of subjects), and included type IV delayed-type hypersensitivity (DTH) reactions at prior DNA inoculation sites in 12 of 28 (43%) subjects following protein vaccination. Systemic reactions revealed two cases of vasculitis temporally related to inoculation with recombinant Env protein+QS21 adjuvant. Questions remain regarding the cause of the vasculitis, but the unique DTH observation may have contributed to the high level of immune responses previously reported for this vaccine.

Head-head and head-tail interaction: a general mechanism for switching off myosin II activity in cells

HyunSuk Jung — Thu, 05 Nov 2009 11:32:16 PST

Intramolecular interaction between myosin heads, blocking key sites involved in actin-binding and ATPase activity, appears to be a critical mechanism for switching off vertebrate smooth-muscle myosin molecules, leading to relaxation. We have tested the hypothesis that this interaction is a general mechanism for switching off myosin II-based motile activity in both muscle and nonmuscle cells. Electron microscopic images of negatively stained myosin II molecules were analyzed by single particle image processing. Molecules from invertebrate striated muscles with phosphorylation-dependent regulation showed head-head interactions in the off-state similar to those in vertebrate smooth muscle. A similar structure was observed in nonmuscle myosin II (also phosphorylation-regulated). Surprisingly, myosins from vertebrate skeletal and cardiac muscle, which are not intrinsically regulated, undergo similar head-head interactions in relaxing conditions. In all of these myosins, we also observe conserved interactions between the 'blocked' myosin head and the myosin tail, which may contribute to the switched-off state. These results suggest that intramolecular head-head and head-tail interactions are a general mechanism both for inducing muscle relaxation and for switching off myosin II-based motile activity in nonmuscle cells. These interactions are broken when myosin is activated.

Oncofetal protein IMP3: a novel molecular marker that predicts metastasis of papillary and chromophobe renal cell carcinomas

Zhong Jiang — Thu, 05 Nov 2009 11:32:11 PST

BACKGROUND: Whether an oncofetal protein, IMP3, can serve as a prognostic biomarker to predict metastasis for patients with localized papillary and chromophobe subtypes of renal cell carcinomas (RCCs) was investigated. METHODS: The expression of IMP3 in 334 patients with primary papillary and chromophobe RCC from multiple medical centers was evaluated by immunohistochemistry. The 317 patients with localized papillary and chromophobe RCCs were further evaluated for outcome analyses. RESULTS: IMP3 was significantly increased in a subset of localized papillary and chromophobe RCCs that subsequently metastasized. Patients with localized IMP3-positive tumors (n=33; 10%) were over 10 times more likely to metastasize (risk ratio [RR], 11.38; 95% confidence interval [CI], 5.40-23.96; P<.001) and were nearly twice as likely to die (RR, 1.91; 95% CI, 1.13-3.22; P=.016) compared with patients with localized IMP3 negative tumors. The 5-year metastasis-free and overall survival rates were 64% and 58% for patients with IMP3-positive localized papillary and chromophobe RCCs compared with 98% and 85% for patients with IMP3 negative tumors, respectively. In multivariable analysis adjusting for the TNM stage and nuclear grade, patients with IMP3-positive tumors were still over 10 times more likely to progress to distant metastasis (RR, 13.45; 95% CI, 6.00-30.14; P<.001) and were still nearly twice as likely die (RR, 1.95; 95% CI, 1.15-3.31; P=.013) compared with patients with IMP3-negative tumors. CONCLUSIONS: IMP3 is an independent prognostic biomarker that can be used to identify a subgroup of patients with localized papillary and chromophobe RCC who are at high risk for developing distant metastasis.

An interaction between the SRP receptor and the translocon is critical during cotranslational protein translocation

Ying Jiang — Thu, 05 Nov 2009 11:32:06 PST

The signal recognition particle (SRP)-dependent targeting pathway facilitates rapid, efficient delivery of the ribosome-nascent chain complex (RNC) to the protein translocation channel. We test whether the SRP receptor (SR) locates a vacant protein translocation channel by interacting with the yeast Sec61 and Ssh1 translocons. Surprisingly, the slow growth and cotranslational translocation defects caused by deletion of the transmembrane (TM) span of yeast SRbeta (SRbeta-DeltaTM) are exaggerated when the SSH1 gene is disrupted. Disruption of the SBH2 gene, which encodes the beta subunit of the Ssh1p complex, likewise causes a growth defect when combined with SRbeta-DeltaTM. Cotranslational translocation defects in the ssh1DeltaSRbeta-DeltaTM mutant are explained by slow and inefficient in vivo gating of translocons by RNCs. A critical function for translocation channel beta subunits in the SR-channel interaction is supported by the observation that simultaneous deletion of Sbh1p and Sbh2p causes a defect in the cotranslational targeting pathway that is similar to the translocation defect caused by deletion of either subunit of the SR.

Epigenetics in the nervous system

Yan Jiang — Thu, 05 Nov 2009 11:32:01 PST

It is becoming increasingly clear that epigenetic modifications are critical factors in the regulation of gene expression. With regard to the nervous system, epigenetic alterations play a role in a diverse set of processes and have been implicated in a variety of disorders. Gaining a more complete understanding of the essential components and underlying mechanisms involved in epigenetic regulation could lead to novel treatments for a number of neurological and psychiatric conditions.

Phagocytosis and intracellular killing of MD-2 opsonized gram-negative bacteria depend on TLR4 signaling

Vishal Jain — Thu, 05 Nov 2009 11:31:56 PST

Both Toll-like receptor 4 (TLR4)- and MD-2-deficient mice succumb to otherwise nonfatal gram-negative bacteria inocula, demonstrating the pivotal role played by these proteins in antibacterial defense in mammals. MD-2 is a soluble endogenous ligand for TLR4 and a receptor for lipopolysaccharide (LPS). LPS-bound MD-2 transmits an activating signal onto TLR4. In this report, we show that both recombinant and endogenous soluble MD-2 bind tightly to the surface of live gram-negative bacteria. As a consequence, MD-2 enhances cellular activation, bacterial internalization, and intracellular killing, all in a TLR4-dependent manner. The enhanced internalization of MD-2-coated bacteria was not observed in macrophages expressing Lps(d), a signaling-incompetent mutant form of TLR4, suggesting that the enhanced phagocytosis observed is dependent on signal transduction. The data confirm the notion that soluble MD-2 is a genuine opsonin that enhances proinflammatory opsonophagocytosis by bridging live gram-negative bacteria to the LPS transducing complex. The presented results extend our understanding of the role of the TLR4/MD-2 signaling axis in bacterial recognition by phagocytes.

Overexpression of thiol/disulfide isomerases enhances membrane fusion directed by the Newcastle disease virus fusion protein

Surbhi Jain — Thu, 05 Nov 2009 11:31:51 PST

Newcastle disease virus (NDV) fusion (F) protein directs membrane fusion, which is required for virus entry and cell-cell fusion. We have previously shown that free thiols are present in cell surface-expressed NDV F protein and that blocking the production of free thiols by thiol-disulfide exchange inhibitors inhibited the membrane fusion mediated by F protein (J Virol. 81:2328-2339, 2007). Extending these observations, we evaluated the role of the overexpression of two disulfide bond isomerases, protein disulfide isomerase (PDI) and ERdj5, in cell-cell fusion mediated by NDV glycoproteins. The overexpression of these isomerases resulted in significantly increased membrane fusion, as measured by syncytium formation and content mixing. The overexpression of these isomerases enhanced the production of free thiols in F protein when expressed without hemagglutination-neuraminidase (HN) protein but decreased free thiols in F protein expressed with HN protein. By evaluating the binding of conformation-sensitive antibodies, we found that the overexpression of these isomerases favored a postfusion conformation of surface-expressed F protein in the presence of HN protein. These results suggest that isomerases belonging to the PDI family catalyze the production of free thiols in F protein, and free thiols in F protein facilitate membrane fusion mediated by F protein.

Role of thiol/disulfide exchange in newcastle disease virus entry

Surbhi Jain — Thu, 05 Nov 2009 11:31:46 PST

Newcastle disease virus (NDV) entry into host cells is mediated by the hemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins. We previously showed that production of free thiols in F protein is required for membrane fusion directed by F protein (S. Jain et al., J. Virol. 81:2328-2339, 2007). In the present study we evaluated the oxidation state of F protein in virions and virus-like particles and its relationship to activation of F protein by HN protein, F protein conformational intermediates, and virus-cell fusion. F protein, in particles, does not have free thiols, but free thiols were produced upon binding of particles to target cells. Free thiols were produced at 16 degrees C in F protein in virions bound to the target cells. They also appeared in different fusion defective mutant F proteins. Free thiols were produced in the presence of mutant HN proteins that are defective in F protein activation but are attachment competent. These results suggest that free thiols appear prior to any of the proposed major conformational changes in F protein which accompany fusion activation. These results also indicate that HN protein binding to its receptor likely facilitates the interaction between F protein and host cell isomerases, leading to reduction of disulfide bonds in F protein. Taken together, these results show that free thiols are produced in F protein at a very early stage during the onset of fusion and that the production of free thiols is required for fusion in addition to activation by HN protein.

Paramyxoviruses: different receptors - different mechanisms of fusion

Ronald M. Iorio — Thu, 05 Nov 2009 11:31:42 PST

Paramyxovirus-mediated membrane fusion usually requires an interaction between the viral-attachment and -fusion proteins. The mechanism by which this interaction regulates fusion differs between paramyxoviruses that bind to sialic acid-containing receptors and those that recognize specific proteins. The recently solved structure of the globular head of the measles virus hemagglutinin suggests that this difference might be related to the location of the receptor-binding sites on the attachment proteins of the two classes of paramyxoviruses.

Design principles for phase-splitting behaviour of coupled cellular oscillators: clues from hamsters with 'split' circadian rhythms

Premananda Indic — Thu, 05 Nov 2009 11:31:37 PST

Nonlinear interactions among coupled cellular oscillators are likely to underlie a variety of complex rhythmic behaviours. Here we consider the case of one such behaviour, a doubling of rhythm frequency caused by the spontaneous splitting of a population of synchronized oscillators into two subgroups each oscillating in anti-phase (phase-splitting). An example of biological phase-splitting is the frequency doubling of the circadian locomotor rhythm in hamsters housed in constant light, in which the pacemaker in the suprachiasmatic nucleus (SCN) is reconfigured with its left and right halves oscillating in anti-phase. We apply the theory of coupled phase oscillators to show that stable phase-splitting requires the presence of negative coupling terms, through delayed and/or inhibitory interactions. We also find that the inclusion of real biological constraints (that the SCN contains a finite number of non-identical noisy oscillators) implies the existence of an underlying non-uniform network architecture, in which the population of oscillators must interact through at least two types of connections. We propose that a key design principle for the frequency doubling of a population of biological oscillators is inhomogeneity of oscillator coupling.

Multisite phosphorylation regulates Bim stability and apoptotic activity

Anette Hubner — Thu, 05 Nov 2009 11:31:32 PST

The proapoptotic BH3-only protein Bim is established to be an important mediator of signaling pathways that induce cell death. Multisite phosphorylation of Bim by several members of the MAP kinase group is implicated as a regulatory mechanism that controls the apoptotic activity of Bim. To test the role of Bim phosphorylation in vivo, we constructed mice with a series of mutant alleles that express phosphorylation-defective Bim proteins. We show that mutation of the phosphorylation site Thr-112 causes decreased binding of Bim to the antiapoptotic protein Bcl2 and can increase cell survival. In contrast, mutation of the phosphorylation sites Ser-55, Ser-65, and Ser-73 can cause increased apoptosis because of reduced proteasomal degradation of Bim. Together, these data indicate that phosphorylation can regulate Bim by multiple mechanisms and that the phosphorylation of Bim on different sites can contribute to the sensitivity of cellular apoptotic responses.

Spectrum of medium-chain acyl-CoA dehydrogenase deficiency detected by newborn screening

Ho-Wen Hsu — Thu, 05 Nov 2009 11:31:27 PST

OBJECTIVE: Our goal was to describe the clinical spectrum of medium-chain acyl-CoA dehydrogenase deficiency detected by routine newborn screening and assess factors associated with elevations of octanoylcarnitine in newborns and characteristics associated with adverse clinical consequences of medium-chain acyl-CoA dehydrogenase deficiency. METHODS: The first 47 medium-chain acyl-CoA dehydrogenase deficiency cases detected by the New England Newborn Screening Program were classified according to initial and follow-up octanoylcarnitine values, octanoylcarnitine-decanoylcarnitine ratios, medium-chain acyl-CoA dehydrogenase genotype, follow-up biochemical parameters, and feeding by breast milk or formula. RESULTS: All 20 patients who were homozygous for 985A-->G had high initial octanoylcarnitine values (7.0-36.8 microM) and octanoylcarnitine-decanoylcarnitine ratios (7.0-14.5), whereas the 27 patients with 0 to 1 copy of 985A-->G exhibited a wide range of octanoylcarnitine values (0.5-28.6 microM) and octanoylcarnitine-decanoylcarnitine ratios (0.8-12.7). Initial newborn octanoylcarnitine values decreased by days 5 to 8, but the octanoylcarnitine-decanoylcarnitine ratio generally remained stable. Among 985A-->G homozygotes, breastfed newborns had higher initial octanoylcarnitine values than newborns who received formula. Adverse events occurred in 5 children, 4 985A-->G homozygotes and 1 compound heterozygote with a very high initial octanoylcarnitine: 2 survived severe neonatal hypoglycemia, 1 survived a severe hypoglycemic episode at 15 months of age, and 2 died as a result of medium-chain acyl-CoA dehydrogenase deficiency at ages 11 and 33 months. CONCLUSION: Newborn screening for medium-chain acyl-CoA dehydrogenase deficiency has detected cases with a wide range of genotypes and biochemical abnormalities. Although most children do well, adverse outcomes have not been entirely avoided. Assessment of potential risk and determination of appropriate treatment remain a challenge.

Design and delivery of antisense oligonucleotides to block microRNA function in cultured Drosophila and human cells

Michael D. Horwich — Thu, 05 Nov 2009 11:31:22 PST

MicroRNAs (miRNAs), approximately 22-nt RNAs that mediate post-transcriptional regulation of mRNAs in animals and plants, are a diverse class of regulatory genes whose specific biological functions are largely unknown. Here we detail a protocol to design and introduce into cultured Drosophila and human cells sequence-specific antisense oligonucleotides (ASOs) that block the function of individual miRNAs. Coupled with recent studies that catalog the miRNAs expressed in diverse cultured cells, our method offers a rapid (<1 week) approach to validate miRNA targets and to study the cellular functions of individual human and Drosophila miRNAs. ASO-based inactivation of miRNAs is faster and simpler than comparable genetic or 'sponge'-based approaches, for which extensive recombinant DNA manipulation is required. We present our ASO design principles and an optimized transfection protocol in which transfection efficiency of Drosophila Schneider 2 cells can approach 100%. Our 3'-cholesterol-modified ASOs have enhanced potency, allowing miRNA inhibition for at least 7 d from a single transfection.

Microcystic adnexal carcinoma: an immunohistochemical reappraisal

Mai P. Hoang — Thu, 05 Nov 2009 11:31:16 PST

Even though immunohistochemical comparisons of microcystic adnexal carcinoma vs infiltrative basal cell carcinoma and desmoplastic trichoepithelioma exist, they are mostly restricted to the use of a single stain. In addition, a comparison with squamous cell carcinoma has not been reported previously. In this study, we compare the expression of cytokeratin (CK) 15, CK7, CK20, CK903, carcinoembryonic antigen (CEA), CD10, CD15 and BerEP4 in 13 microcystic adnexal carcinoma, eight desmoplastic trichoepithelioma, 10 infiltrative basal cell carcinoma, and eight squamous cell carcinoma of which five exhibited ductal differentiation. We found that the majority of microcystic adnexal carcinoma (92%) and desmoplastic trichoepithelioma (100%) cases expressed CK15 while the infiltrative basal cell carcinoma and squamous cell carcinoma cases were all negative. Forty percent of infiltrative basal cell carcinoma expressed CK7; while only two microcystic adnexal carcinoma cases (15%) and one squamous cell carcinoma with ductal differentiation (12%) expressed CK7 in the remaining three tumor categories. None of the desmoplastic trichoepithelioma expressed CK7. All tumors were strongly positive for CK903. While the neoplastic cells were negative, luminal staining of ductal structures was noted for CK7, CD15 and CEA in some of the microcystic adnexal carcinoma, desmoplastic trichoepithelioma and squamous cell carcinoma with ductal differentiation cases. Sixty percent of infiltrative basal cell carcinoma, 31% of microcystic adnexal carcinoma, and 25% of squamous cell carcinoma express CD10. BerEP4 expression was noted in 38% of microcystic adnexal carcinoma, 57% of desmoplastic trichoepithelioma, 100% of infiltrative basal cell carcinoma, and 38% of squamous cell carcinoma. In conclusion, we found CK15 to be a useful marker in distinguishing microcystic adnexal carcinoma from infiltrative basal cell carcinoma and squamous cell carcinoma with ductal differentiation. Our experience indicates that microcystic adnexal carcinoma and desmoplastic trichoepithelioma have a similar immunohistochemical profile that is, CK15+ and BerEP4+/-; thus, additional studies are needed to separate these two entities.

CD40 on APCs is needed for optimal programming, maintenance, and recall of CD8+ T cell memory even in the absence of CD4+ T cell help

Maria Genevieve H. Hernandez — Thu, 05 Nov 2009 11:31:11 PST

CD40 stimulation is one of the many signals that can activate APCs and we have recently shown it to have a unique function in generating maximum primary CD8(+) T cell responses. However, whether CD40 signaling plays a role in memory CD8(+) T cell responses is still not completely understood. In this study, we show that in the absence of CD40 on all APCs or specifically on dendritic cells, memory CD8(+) T cells are generated but at significantly reduced levels. This reduction is due to a contribution of CD40 at several different steps in the generation of CD8(+) memory. In the initial T cell response, CD40 contributes to maximizing not only the number of effector cells that are generated but also the programming of ones that will differentiate into memory. Subsequently, CD40 is needed to maintain maximal numbers of the committed memory cells in a manner that is independent of the immunizing Ag. Finally, when memory CD8(+) T cells are reactivated there is a variable requirement for CD40 depending on whether CD40 or CD4(+) Th cells were present during the primary response. Therefore, CD40 signaling on APCs plays an important role in all phases of a memory CD8(+) T cell response.

Outer-membrane transport of aromatic hydrocarbons as a first step in biodegradation

Elizabeth M. Hearn — Thu, 05 Nov 2009 11:31:06 PST

Bacterial biodegradation of hydrocarbons, an important process for environmental remediation, requires the passage of hydrophobic substrates across the cell membrane. Here, we report crystal structures of two outer membrane proteins, Pseudomonas putida TodX and Ralstonia pickettii TbuX, which have been implicated in hydrocarbon transport and are part of a subfamily of the FadL fatty acid transporter family. The structures of TodX and TbuX show significant differences with those previously determined for Escherichia coli FadL, which may provide an explanation for the substrate-specific transport of TodX and TbuX observed with in vivo transport assays. The TodX and TbuX structures revealed 14-stranded beta-barrels with an N-terminal hatch domain blocking the barrel interior. A hydrophobic channel with bound detergent molecules extends from the extracellular surface and is contiguous with a passageway through the hatch domain, lined by both hydrophobic and polar or charged residues. The TodX and TbuX structures support a mechanism for transport of hydrophobic substrates from the extracellular environment to the periplasm via a channel through the hatch domain.

Targeted mutation of mouse skeletal muscle sodium channel produces myotonia and potassium-sensitive weakness

Lawrence J. Hayward — Thu, 05 Nov 2009 11:31:00 PST

Hyperkalemic periodic paralysis (HyperKPP) produces myotonia and attacks of muscle weakness triggered by rest after exercise or by K+ ingestion. We introduced a missense substitution corresponding to a human familial HyperKPP mutation (Met1592Val) into the mouse gene encoding the skeletal muscle voltage-gated Na+ channel NaV1.4. Mice heterozygous for this mutation exhibited prominent myotonia at rest and muscle fiber-type switching to a more oxidative phenotype compared with controls. Isolated mutant extensor digitorum longus muscles were abnormally sensitive to the Na+/K+ pump inhibitor ouabain and exhibited age-dependent changes, including delayed relaxation and altered generation of tetanic force. Moreover, rapid and sustained weakness of isolated mutant muscles was induced when the extracellular K+ concentration was increased from 4 mM to 10 mM, a level observed in the muscle interstitium of humans during exercise. Mutant muscle recovered from stimulation-induced fatigue more slowly than did control muscle, and the extent of recovery was decreased in the presence of high extracellular K+ levels. These findings demonstrate that expression of the Met1592ValNa+ channel in mouse muscle is sufficient to produce important features of HyperKPP, including myotonia, K+-sensitive paralysis, and susceptibility to delayed weakness during recovery from fatigue.

A Rictor-Myo1c complex participates in dynamic cortical actin events in 3T3-L1 adipocytes

G. Nana Hagan — Thu, 05 Nov 2009 11:30:55 PST

Insulin signaling through phosphatidylinositol 3-kinase (PI 3-kinase) activates the protein kinase Akt through phosphorylation of its threonine 308 and serine 473 residues by the PDK1 protein kinase and the Rictor-mammalian target of rapamycin complex (mTORC2), respectively. Remarkably, we show here that the Rictor protein is also present in cultured adipocytes in complexes containing Myo1c, a molecular motor that promotes cortical actin remodeling. Interestingly, the Rictor-Myo1c complex is biochemically distinct from the previously reported mTORC2 and can be immunoprecipitated independently of mTORC2. Furthermore, while RNA interference-directed silencing of Rictor results in the expected attenuation of Akt phosphorylation at serine 473, depletion of Myo1c is without effect. In contrast, loss of either Rictor or Myo1c inhibits phosphorylation of the actin filament regulatory protein paxillin at tyrosine 118. Furthermore, Myo1c-induced membrane ruffling of 3T3-L1 adipocytes is also compromised following Rictor knockdown. Interestingly, neither the mTORC2 inhibitor rapamycin nor the PI 3-kinase inhibitor wortmannin affects paxillin tyrosine 118 phosphorylation. Taken together, our findings suggest that the Rictor-Myo1c complex is distinct from mTORC2 and that Myo1c, in conjunction with Rictor, participates in cortical actin remodeling events.

Transcription factor functionality and transcription regulatory networks

Christian A. Grove — Thu, 05 Nov 2009 11:30:49 PST

Now that numerous high-quality complete genome sequences are available, many efforts are focusing on the "second genomic code", namely the code that determines how the precise temporal and spatial expression of each gene in the genome is achieved. In this regard, the elucidation of transcription regulatory networks that describe combined transcriptional circuits for an organism of interest has become valuable to our understanding of gene expression at a systems level. Such networks describe physical and regulatory interactions between transcription factors (TFs) and the target genes they regulate under different developmental, physiological, or pathological conditions. The mapping of high-quality transcription regulatory networks depends not only on the accuracy of the experimental or computational method chosen, but also relies on the quality of TF predictions. Moreover, the total repertoire of TFs is not only determined by the protein-coding capacity of the genome, but also by different protein properties, including dimerization, co-factor interactions and post-translational modifications. Here, we discuss the factors that influence TF functionality and, hence, the functionality of the networks in which they operate.

Association between dietary glycemic index, glycemic load, and high-sensitivity C-reactive protein

Jennifer A. Griffith — Thu, 05 Nov 2009 11:30:43 PST

OBJECTIVE: This study examined the relation between quality of dietary carbohydrate intake, as measured by glycemic index (GI) and glycemic load (GL), and serum high-sensitivity C-reactive protein (hs-CRP) levels. METHODS: During a 1-y observational study, data were collected at baseline and at each quarter thereafter. GI and GL were calculated from multiple 24-h dietary recalls (24HRs), 3 randomly selected 24HRs at every quarter, with up to 15 24HRs per participant. The hs-CRP was measured in blood samples collected at baseline and each of the four quarterly measurement points. Multivariable linear mixed models were used to examine the cross-sectional and longitudinal associations of GI, GL, and hs-CRP. RESULTS: Among 582 adult men and women with at least two measurements of diet and hs-CRP, average daily GI score (white bread = 100) was 85 and average GL was 198, and average hs-CRP was 1.84 mg/L. Overall, there was no association between GI or GL and hs-CRP. Subgroup analyses revealed an inverse association between GL and hs-CRP among obese individuals (body mass index > or =30 kg/m(2)). CONCLUSION: Quality of dietary carbohydrates does not appear to be associated with serum hs-CRP levels. Among obese individuals, higher dietary GL appears to be related to lower hs-CRP levels. Due to the limited number of studies on this topic and their conflicting results, further investigation is warranted.

Runx2 induces acute myeloid leukemia in cooperation with Cbfbeta-SMMHC in mice

Ya-Huei Kuo — Wed, 04 Nov 2009 10:30:03 PST

The core-binding factor (CBF) is a master regulator of developmental and differentiation programs, and CBF alterations are frequently associated with acute leukemia. The role of the CBF member RUNX2 in hematopoiesis is poorly understood. Genetic evidence suggests that deregulation of Runx2 may cause myeloid leukemia in mice expressing the fusion oncogene Cbfb-MYH11. In this study, we show that sustained expression of Runx2 modulates Cbfbeta-smooth muscle myosin heavy chain (SMMHC)-mediated myeloid leukemia development. Expression of Runx2 is high in the hematopoietic stem cell compartment and decreases during myeloid differentiation. Sustained Runx2 expression hinders myeloid progenitor differentiation capacity and represses expression of CBF targets Csf1R, Mpo, Cebpd, the cell cycle inhibitor Cdkn1a, and myeloid markers Cebpa and Gfi1. In addition, full-length Runx2 cooperates with Cbfbeta-SMMHC in leukemia development in transplantation assays. Furthermore, we show that the nuclear matrix-targeting signal and DNA-binding runt-homology domain of Runx2 are essential for its leukemogenic activity. Conversely, Runx2 haplo-insufficiency delays the onset and reduces the incidence of acute myeloid leukemia. Together, these results indicate that Runx2 is expressed in the stem cell compartment, interferes with differentiation and represses CBF targets in the myeloid compartment, and modulates the leukemogenic function of Cbfbeta-SMMHC in mouse leukemia.

Transcription-factor-mediated epigenetic control of cell fate and lineage commitment

Gary S. Stein — Wed, 04 Nov 2009 10:30:02 PST

Epigenetic control is required to maintain competency for the activation and suppression of genes during cell division. The association between regulatory proteins and target gene loci during mitosis is a parameter of the epigenetic control that sustains the transcriptional regulatory machinery that perpetuates gene-expression signatures in progeny cells. The mitotic retention of phenotypic regulatory factors with cell cycle, cell fate, and tissue-specific genes supports the coordinated control that governs the proliferation and differentiation of cell fate and lineage commitment.

Organization, integration, and assembly of genetic and epigenetic regulatory machinery in nuclear microenvironments: implications for biological control in cancer

Gary S. Stein — Wed, 04 Nov 2009 10:30:00 PST

There is growing awareness that the fidelity of gene expression necessitates coordination of transcription factor metabolism and organization of genes and regulatory proteins within the three-dimensional context of nuclear architecture. The regulatory machinery that governs genetic and epigenetic control of gene expression is compartmentalized in nuclear microenvironments. Temporal and spatial parameters of regulatory complex organization and assembly are functionally linked to biological control and are compromised with the onset and progression of tumorigenesis. High throughput imaging of cells, tissues, and tumors, including live cell analysis, is expanding research's capabilities toward translating components of nuclear organization into novel strategies for cancer diagnosis and therapy.

Altered Runx1 subnuclear targeting enhances myeloid cell proliferation and blocks differentiation by activating a miR-24/MKP-7/MAPK network

Sayyed K. Zaidi — Wed, 04 Nov 2009 10:29:59 PST

Disruption of Runx1/AML1 subnuclear localization, either by a single amino acid substitution or by a chromosomal translocation [e.g., t(8;21)], is linked to the etiology of acute myeloid leukemia (AML). Here, we show that this defect induces a select set of micro-RNAs (miR) in myeloid progenitor cells and AML patients with t(8;21). Both Runx1 and the t(8;21)-encoded AML1-ETO occupy the miR-24-23-27 locus and reciprocally control miR-24 transcription. miR-24 directly downregulates mitogen-activated protein kinase (MAPK) phosphatase-7 and enhances phosphorylation of both c-jun-NH(2)-kinase and p38 kinases. Expression of miR-24 stimulates myeloid cell growth, renders proliferation independent of interleukin-3, and blocks granulocytic differentiation. Thus, compromised Runx1 function induces a miR-dependent mechanism that, through MAPK signaling, enhances myeloid proliferation but blocks differentiation--key steps that contribute to leukemia.

Barium enemas in the frail elderly.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:31 PST

PURPOSE: The objective of this investigation was to determine the frequency of and predictors for inadequate barium enemas in the frail elderly. PATIENTS AND METHODS: The medical and radiologic records of 171 elderly institutionalized patients (mean age = 85.3 years), who underwent barium enema examinations, were retrospectively reviewed. The study outcome of primary interest was the radiologist's report of the adequacy of examination as indicated in the written summary of the results of the barium enema procedure. RESULTS: Eighty-eight (51.5%) of the 171 studies were deemed inadequate, with poor bowel preparation a primary or contributing factor in 89.7% of the inadequate studies. Among a variety of demographic and clinical factors, only long-term laxative and/or cathartic use was associated with an inadequate study (odds ratio = 7.0; 95% confidence interval 2.7 to 18.0). CONCLUSION: These results demonstrate a very high frequency of inadequate barium enema examinations in the very old and suggest a need for improved methods of bowel preparation in this patient population, especially in those who are long-term users of laxatives and cathartics.

Diagnostic testing in acute myocardial infarction: does patient age influence utilization patterns? The Worcester Heart Attack Study.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:31 PST

To assess the impact of patient age on the use of diagnostic testing in the management of acute myocardial infarction, the authors reviewed the hospital charts of 4,109 patients hospitalized for validated acute myocardial infarction in the Worcester, Massachusetts, metropolitan area during selected years between 1975 and 1986. Older patients were more likely to be female and to have a prior history of angina, hypertension, and diabetes mellitus (p less than 0.001). Acute myocardial infarctions among older patients were more likely to be recurrent, anterior in location, non-Q wave, smaller as reflected by peak creatine kinase levels, and complicated by congestive heart failure, cardiogenic shock, and atrial fibrillation (p less than 0.001). In-hospital mortality was directly related to increasing patient age (p less than 0.001). Patterns of utilization of the following diagnostic tests were examined: Holter monitoring, radionuclide ventriculography, echocardiography, exercise testing, pulmonary artery catheterization, and coronary arteriography. After adjustment for differences in demographic and clinical characteristics and in-hospital mortality, patients aged 65 years and older were significantly less likely to undergo exercise testing than were patients less than age 55. Patients older than age 75 were significantly less likely to undergo radionuclide ventriculography, pulmonary artery catheterization, and coronary arteriography than were younger patients. Sex-specific analyses did not produce results substantially different from those for the overall study population. The results of this community-wide study suggest that among patients hospitalized for acute myocardial infarction, chronologic age may be an independent determinant of utilization patterns of diagnostic testing. These findings suggest the need for a prospective evaluation of this issue, with an additional emphasis placed on the contributions of functional status and noncardiovascular illness to decision-making in the clinical management of acute myocardial infarction patients.

Potassium homeostasis with indomethacin therapy in normal subjects.

David M. Clive — Tue, 03 Nov 2009 11:04:29 PST

In an attempt to delineate effects of prostaglandin (PG) synthesis inhibition on potassium metabolism in normal subjects, we challenged 13 young, healthy volunteers with a potassium chloride infusion before and after a 4-day course of indomethacin (25 mg orally, three times a day). The plasma potassium level was monitored at 10-minute intervals throughout the 50-minute infusion and for a total of 180 minutes. The maximal increment in plasma potassium level was 0.82 +/- 0.07 mmol/L (mEq/L) in the untreated state, and 0.86 +/- 0.08 mmol/L with indomethacin treatment. The basal potassium level before infusion was higher in the indomethacin-treated than the control state (3.83 +/- 0.07 v 3.68 +/- 0.07 mmol/L; P less than 0.01). Urinary potassium excretion over the 3-hour study period equalled the potassium load administered, and was unaffected by indomethacin therapy. Indomethacin did not alter insulin or aldosterone levels during the study. PGE2 excretion over the 3 hours was lower in the indomethacin than the control phase, although it was higher than normal in both phases. In an additional experiment, the comparative effects of a saline versus saline-potassium infusion on PG excretion were studied. No differences were seen between the excretion patterns of PGE2 or 6-keto-PGF1a with the two infusions. We conclude that (1) although basal serum potassium level is slightly higher in healthy young people during indomethacin treatment, there is little effect on handling of an acute potassium load; (2) the aldosterone response to hyperkalemia is PG-independent; (3) urinary PG excretion increases in response to a saline-based infusion, but the effect is not enhanced by acute potassium loading.

Reducing the use of H2-receptor antagonists in the long-term-care setting.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:28 PST

OBJECTIVES: To examine the patterns of H2 blocker use in the long-term-care setting and to assess the effect of educational interventions designed to improve H2 blocker utilization patterns. DESIGN: Time-series quasi-experimental study and retrospective chart review. SETTING: A large academically-oriented long-term-care facility. PATIENTS: Institutionalized elderly patients with a mean age of 88 years receiving H2 blocker therapy. INTERVENTIONS: Two interventions involving group discussions with the medical staff, supporting educational materials, and physician-specific listings of patients receiving H2 blockers were employed sequentially over a 32-month period. RESULTS: Each intervention resulted in substantial reductions in medication use (59.6% and 32.1%, respectively). Indications for H2 blocker use were determined retrospectively for patients identified as receiving therapy prior to the interventions (n = 110). Forty-one percent were found to be receiving therapy for reasons unsubstantiated by the medical literature. These patients were more likely to be discontinued from therapy than those receiving therapy for substantiated indications (P less than 0.01), consistent with the primary focus of the educational interventions. CONCLUSIONS: These results suggest that the excessive use of H2 blocker therapy in the long-term care setting responds to educational interventions with therapeutically appropriate reductions in utilization. Repeated interventions are necessary to maintain such reductions over time although there may be some reduction in the effectiveness of the intervention with repetition.

Aging and the anticoagulant response to warfarin therapy.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:27 PST

OBJECTIVE: To assess the effect of aging on the anticoagulant response to warfarin. DESIGN: Retrospective cohort study. SETTING: A university hospital outpatient anticoagulation clinic. PATIENTS: All patients (n = 530) monitored in the anticoagulation clinic over a 10-year period (1980 to 1990). The 530 study patients had a mean age of 61.5 (+/- 14.7) years (age range, 12 to 90 years). The patients were stratified into four age groups: younger than 50 years (n = 97); 50 to 59 years (n = 107); 60 to 69 years (n = 149); and 70 years or older (n = 177). MEASUREMENTS: For each patient, a dose-adjusted mean prothrombin time ratio was calculated by dividing the mean prothrombin time ratio by the mean daily warfarin dose. RESULTS: Older patients were more likely to be female (P less than 0.001), to have more medical problems (P less than 0.001), to be taking more medications (P less than 0.001), and to weigh less than younger patients (P less than 0.001). Across age groups, there were no significant differences in the use of medications that potentiated or inhibited the anticoagulant effects of warfarin. The prothrombin time ratio, when adjusted for dose, was significantly increased in older patients (P less than 0.001). The increased anticoagulant response to warfarin seen with increasing patient age persisted even after simultaneously controlling for relevant demographic and clinical variables in a multivariate model. Other factors significantly associated with an increased sensitivity to warfarin included use of a medication with a potentiating interactive effect with warfarin, female gender, and overall medication use. Increased body weight and duration of warfarin use exceeding 6 months were found to be inversely related to anticoagulant response. CONCLUSION: The anticoagulant response to warfarin is exaggerated with advancing age. This finding emphasizes the need for close monitoring of older patients treated with warfarin therapy.

The exclusion of the elderly and women from clinical trials in acute myocardial infarction.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:26 PST

OBJECTIVE--To determine the extent to which the elderly have been excluded from trials of drug therapies used in the treatment of acute myocardial infarction, to identify factors associated with such exclusions, and to explore the relationship between the exclusion of elderly and the representation of women. DATA SOURCES--We conducted a systematic search of the English-language literature from January 1960 through September 1991 to identify all relevant studies of specific pharmacotherapies employed in the treatment of acute myocardial infarction. To accomplish this, we searched MEDLINE, major cardiology textbooks, meta-analyses, reviews, editorials, and the bibliographies of all identified articles. STUDY SELECTION--Only trials in which patients were randomly allocated to receive a specific therapeutic regimen or a placebo or nonplacebo control regimen were included for review. DATA EXTRACTION--Studies were abstracted for year of publication, source of support, performance location, drug therapies to which patients were randomized, use of invasive diagnostic tests or therapeutic procedures, exclusion criteria, size and demographic characteristics of the randomized study population, and principal outcome measures. DATA SYNTHESIS--A total of 214 trials met inclusion criteria, involving 150,920 study subjects. Over 60% of trials excluded persons over the age of 75 years. Studies published after 1980 were more likely to have age-based exclusions compared with studies published before 1980 (adjusted odds ratio, 4.92; 95% confidence interval, 2.33 to 10.54). Trials of thrombolytic therapy involving an invasive procedure were more likely to exclude elderly patients compared with other studies (adjusted odds ratio, 2.45; 95% confidence interval, 1.10 to 5.47). Studies with age-based exclusions had a smaller percentage of women compared with those without such exclusions (18% vs 23%; P = .0002), with the mean age of the study population significantly associated with the proportion of women participants (P = .0001, R2 = .29). CONCLUSIONS--Age-based exclusions are frequently used in clinical trials of medications used in the treatment of acute myocardial infarction. Such exclusions limit the ability to generalize study findings to the patient population that experiences the most morbidity and mortality from acute myocardial infarction.

Beta-blocker therapy in acute myocardial infarction: evidence for underutilization in the elderly.

Jerry H. Gurwitz — Tue, 03 Nov 2009 11:04:24 PST

PURPOSE: To assess the impact of patient age on the use of beta-blocker therapy in the management of acute myocardial infarction. PATIENTS AND METHODS: The population studied consisted of 4,762 patients hospitalized with validated acute myocardial infarction in 16 hospitals in the Worcester, Massachusetts, Standard Metropolitan Statistical Area during the years 1975, 1978, 1981, 1984, 1986, and 1988. Logistic regression analysis was employed to control for relevant demographic and clinical variables in evaluating the independent effect of patient age as a determinant of receipt of beta-blocker therapy during the hospitalization. RESULTS: A consistent trend toward reduced use of beta-blocker therapy in older patients was demonstrated. After adjustment for demographic and clinical variables (gender; prior history of angina, hypertension, or diabetes mellitus; myocardial infarction characteristics; complications including congestive heart failure and shock; and use of digoxin and diuretics), odds ratios for receipt of beta-blocker therapy relative to patients less than 55 years of age were 0.61 for those 55 to 64; 0.52 for those 65 to 74; 0.36 for those 75 to 84; and 0.26 for those 85 or older. Analyses performed for each study year demonstrated results consistent with those for the overall study population. CONCLUSION: The results of this population-based study suggest that there are substantial opportunities for expanded use of beta-blocker therapy in elderly patients who have sustained an acute myocardial infarction.

Antihypertensive drug therapy and the initiation of treatment for diabetes mellitus.

Jerry H. Gurwitz — Mon, 02 Nov 2009 13:17:09 PST

OBJECTIVE: To quantify the risk for the occurrence of hyperglycemia requiring initiation of therapy among patients taking various antihypertensive regimens. DESIGN: Case-control study. SETTING: New Jersey Medicaid program. PATIENTS: The study included New Jersey Medicaid enrollees 35 years of age or older. The 11,855 case patients were newly started on a hypoglycemic agent (oral agent or insulin) between 1981 and 1990. The 11,855 controls were selected randomly from among other Medicaid enrollees. MEASUREMENTS AND MAIN RESULTS: The frequency of initiation of hypoglycemic therapy was increased for users of virtually all antihypertensive agents relative to nonusers after adjustment for age, gender, race, nursing home residency, number of days hospitalized, total number of prescriptions, and selected medication exposures. The estimated relative risk for initiation of hypoglycemic therapy was 1.40 for patients receiving thiazide diuretics (95% CI, 1.26 to 1.58) and ranged from 1.56 to 1.77 for patients receiving other antihypertensive medications, depending on the medication category. A higher risk was associated with multiple-agent regimens, whether they excluded a thiazide diuretic (odds ratio, 1.76; CI, 1.49 to 2.07) or included one (odds ratio, 1.93; CI, 1.75 to 2.13). When the analysis was restricted to users of antihypertensive agents (n = 8005), the risk associated with other single-agent antihypertensive regimens was not significantly different from that associated with thiazide diuretics. However, patients receiving multiple-agent regimens continued to be at increased risk for hyperglycemia requiring hypoglycemic therapy relative to those who used thiazide diuretic therapy alone. CONCLUSION: The association between antihypertensive therapy and the initiation of treatment for diabetes mellitus is more closely related to the intensity of therapy than to the individual agent used. Our data do not support the hypothesis that thiazide diuretics are more strongly associated with the initiation of hypoglycemic therapy than are other antihypertensive agents.

Treatment for glaucoma: adherence by the elderly.

Jerry H. Gurwitz — Mon, 02 Nov 2009 13:17:08 PST

OBJECTIVES. The purpose of this study was to determine the extent of nonadherence to treatment for glaucoma among elderly patients. METHODS. This was a retrospective cohort study of 2440 patients older than age 65 who were enrolled in the New Jersey Medicaid Program and who were newly initiated on a topical agent for the treatment of glaucoma. Two patient-specific measures of nonadherence were employed: (1) no filled prescription for any glaucoma medication over a 12-month period after the initiation of therapy and (2) number of days without therapy for glaucoma during this 12-month period. RESULTS. By the first measure, 569 patients (23%) were found to be nonadherent. The mean number of days without therapy during the study year was 112. Factors associated with nonadherence included the use of glaucoma medication requiring more than 2 administrations per day and the presence of multiple other medications in the patient's drug regimen. Patients started on multiple glaucoma medication were more adherent than those started on a single agent. Age and sex were not found to be predictors of nonadherence. CONCLUSIONS. Substantial nonadherence was found to be common in this population. More attention to the issue of nonadherence could result in important benefits in the preservation of sight.

Old age and race as determinants of initiation of glaucoma therapy.

Robert J. Glynn — Mon, 02 Nov 2009 11:18:14 PST

Demographic differences in the prevalence of blindness may be partly due to undertreatment of susceptible population subgroups. The authors examined the relation of age, race, and other demographic characteristics with initiation of treatment for glaucoma and compared treatment rates with expected rates based on known disease prevalence. Data were from Medicaid enrollees aged 65-99 years in New Jersey between March 1981 and February 1990. Based on review of all claims for prescription medications and laser and incisional surgery, there were 6,173 cases with at least 6 months of documented system eligibility before their initial treatment for glaucoma. The overall rate of new treatment was 11.5 cases per 1,000 person-years, and increased throughout the 1980s. The age-adjusted relative rate of new treatment was 1.58 times higher in blacks compared with whites; however, this was less than half the relative rate expected based on estimated relative incidence rates. Similarly, enrollees aged 70-99 years had only 7% to 27% higher treatment rates than those aged 65-69 years, substantially less than expected. Treatment for glaucoma was also less likely to be initiated in nursing home residents, compared with those living in the community. Blacks and the very old are much less likely to have treatment for glaucoma initiated than would be predicted based on the magnitude of disease burden in these populations.

Constipation in the elderly.

Danielle Harari — Mon, 02 Nov 2009 11:18:12 PST

OBJECTIVE: To explore the distinction between true clinical constipation and the subjective complaint of constipation in elderly people and to review the pathophysiology, symptoms, diagnosis, causes, and treatment. DATA SOURCES: A computer-assisted and manual search of the English language literature using MEDLINE 1966-1991, Index Medicus 1988-1992, reference lists of selected articles, and relevant textbooks. STUDY SELECTION: Studies that provide information on lower bowel function and laxative and enema use in the elderly subjects were reviewed. Article selection was not limited by study design. DATA EXTRACTION: Relevant data were abstracted from the results of physiological, cohort and case-control studies, and clinical trials. The text discusses the methodological strengths and flaws of these studies and excludes management approaches formulated from uncontrolled clinical observation. RESULTS OF DATA SYNTHESIS: Constipation of the elderly is not well defined in the current literature. Self-reported constipation and laxative use increase with age, while a similar escalation in true clinical constipation is not shown. Physiological changes in the lower bowel predisposing toward constipation do not occur with normal aging. Patient selection criteria for studies examining the pathophysiology of constipation differ in their definition of constipation and their inclusion of coexisting chronic illness. Nevertheless, there is consistent evidence for prolonged transit through the sigmoid colon and rectum, especially in frail elderly patients, and reduced rectal tone with impaired sensation, particularly in patients with rectal impaction. Few studies rigorously examine "risk factors" and non-pharmacological interventions in constipation. The results of most laxative trials require cautious interpretation because of inclusion of patients without diagnostically proven constipation, use of combined laxative preparations, and unreliable outcome measures. Certain laxative agents however appear more appropriate for use in elderly people. CONCLUSION: Although the subjective complaint of constipation and habitual laxative use increase with age, the epidemiological data suggest that true clinical constipation does not. Physiological changes predisposing toward constipation are not an inevitable consequence of aging, but appear to be specific to the condition. The available data do not confirm many suspected "risk factors" nor the benefits of commonly used non-pharmacological and pharmacological treatments, but they do provide enough information to formulate a practical approach to constipation in elderly persons.

Examining product risk in context. Market withdrawal of zomepirac as a case study.

Dennis Ross-Degnan — Mon, 02 Nov 2009 11:18:10 PST

OBJECTIVE--To examine changes in the prescribing of analgesics after the market entry and subsequent withdrawal of zomepirac sodium, a nonsteroidal anti-inflammatory drug (NSAID), following repeated reports of zomepirac-related deaths. DESIGN--To evaluate this natural quasi experiment, we conducted time-series analyses to compare prescribing in two cohorts of primary care physicians from July 1980 through September 1983. SETTING--Study physicians provided outpatient pharmaceutical care to patients enrolled in the New Jersey Medicaid program. PARTICIPANTS--We identified 260 primary care physicians who provided 10 or more prescriptions for zomepirac (zomepirac prescribers) and 308 who provided 10 or more prescriptions for NSAIDs other than zomepirac (other-NSAID prescribers) in Medicaid during the study period. MAIN OUTCOME MEASURES--Monthly rates of prescribing for zomepirac and several categories of substitute analgesics among Medicaid patients seen by study physicians. MAIN RESULTS--Zomepirac accounted for a stable 11.0% of analgesic prescribing among the zomepirac-prescriber cohort; label changes and manufacturer product-risk warnings 11 months before the product's withdrawal from the market had no impact on use. After market entry, zomepirac prescribers reduced use of other NSAIDs and propoxyphene (hydrochloride or napsylate) in comparison with other-NSAID prescribers (-8.1% and -2.8% of total analgesic prescribing, respectively; P < .001). After the product's withdrawal from the market, zomepirac prescribers showed significant increases in relative prescribing of other NSAIDs (+6.8%; P < .001), propoxyphene (+2.1%; P < .05), and analgesics containing barbiturates (+2.7%; P < .001). CONCLUSIONS--The sudden withdrawal of zomepirac from the market resulted in substitutions not only of other NSAIDs, but also of alternative analgesics that carry risks of habituation and adverse effects. Apparent gains in patient safety resulting from market withdrawal of medications must be evaluated in comparison with risks of medications likely to be substituted.

Topical glaucoma medications and cardiovascular risk in the elderly.

Mark Monane — Mon, 02 Nov 2009 11:18:09 PST

OBJECTIVE: To determine the frequency of congestive heart failure and cardiac conduction disturbances in elderly patients treated with topical glaucoma medications. METHODS: These case-control studies were conducted among participants in the New Jersey Medicaid and Medicare program from 1986 to 1990. A total of 35,445 subjects (ages 65 to 99 years) were included in the congestive heart failure analysis, and 4278 subjects were included in the conduction disorder analysis. RESULTS: The frequency of initiation of congestive heart failure therapy, defined as the new use of digoxin or furosemide, was not increased for users of topical glaucoma medications. The frequency of pacemaker placement was also not increased for topical glaucoma medication users. Analyses were adjusted for age, race, gender, nursing home or hospital status, number of prescription medications, and selected medication exposures. Advanced age and heavy use of other prescription medications were associated with an increased likelihood of both cardiovascular outcomes. CONCLUSION: Major cardiovascular side effects did not occur at an increased rate among patients using topical beta-blockers or other glaucoma medications compared with control subjects. This population-based study places findings from case reports and small clinical trials in a broader context to help with clinical assessment of the risks and benefits of glaucoma therapy in the elderly.

The appropriateness of oral fluoroquinolone-prescribing in the long-term care setting.

Terri-Diann Pickering — Mon, 02 Nov 2009 11:18:07 PST

OBJECTIVE: To evaluate the appropriateness of ciprofloxacin-prescribing in the long-term care setting. DESIGN: Retrospective chart review. SETTING: A large academically oriented long-term care facility. PATIENTS: Institutionalized elderly patients with a mean age of 88 years. METHODS: One hundred orders were randomly selected for review from all ciprofloxacin orders initiated over a 3-year period. Criteria for appropriateness of ciprofloxacin-prescribing were developed based on a comprehensive review of the medical literature. Evaluation of appropriateness of prescribing was based on the indication for therapy and the availability of more effective and/or less expensive alternative antibiotic regimens. Only information available to the physician at the time of the order was used to judge appropriateness. Abstracted medical records were evaluated independently by a geriatrician and an infectious diseases specialist. RESULTS: With respect to site of infection, the urinary tract accounted for 43% of all ciprofloxacin orders; the lower respiratory tract, 28%; and skin and soft-tissue infections, 17%. Only 25% of orders were judged appropriate. Twenty-three percent of orders were judged less than appropriate based on indication, and 49% due to the availability of a more effective and/or less expensive alternative antibiotic choice. There was insufficient information in the medical record to judge 3% of the orders. CONCLUSION: These results indicate less than optimal prescribing of oral fluoroquinolones in the long-term care setting, with potential consequences including the development of resistant bacterial strains and increased health care costs.

The epidemiology of adverse and unexpected events in the long-term care setting.

Jerry H. Gurwitz — Mon, 02 Nov 2009 11:18:05 PST

OBJECTIVE: To describe the adverse and unexpected events reported by staff over a 1-year period in a large, long-term care institution. DESIGN: A retrospective review of resident incident reports. SETTING: A 703-bed, academically oriented, long-term care facility. PATIENTS: Residents of the facility have a mean age of 88.5 years, are 76% female, and have an average length of stay of 4.3 years. MEASUREMENTS AND MAIN RESULTS: Of the 3,390 adverse and unexpected events reports over the 1-year study period, falls (with and without associated injury) were the most frequently reported incidents, followed by non-fall-related injuries, medication-related events, and wandering episodes. While a large proportion of falls occurred in ambulating residents (47%), the majority occurred under different circumstances including falls from bed, wheelchair, and commode/toilet. Bruises and skin tears were the most frequently reported fall- and non-fall-related injuries. The annual incidence rates for falls, fall-related injuries, and non-fall-related injuries varied according to resident care unit level, with semi-dependent residents experiencing the highest rates of falls and dependent residents experiencing the highest rates of non-fall-related injuries. Circadian patterns in the incidence of these events varied according to resident care level. CONCLUSIONS: Information regarding adverse and unexpected events in the long-term care setting can be organized into databases that allow analysis of patterns and trends. The results of these analyses may be helpful in targeting limited resources to areas of greatest need within an individual institution and for comparing quality of care across different long-term care facilities.

Glucocorticoids and the risk for initiation of hypoglycemic therapy.

Jerry H. Gurwitz — Mon, 02 Nov 2009 11:18:03 PST

PURPOSE: To quantify risk for the occurrence of hyperglycemia requiring initiation of hypoglycemic therapy in patients treated with oral glucocorticoids. PATIENTS AND METHODS: A case-control study of enrollees in the New Jersey Medicaid program 35 years of age or older. The 11,855 case patients had newly initiated treatment with a hypoglycemic agent (oral or insulin) between 1981 and 1990. The 11,855 controls represented a random sample of other Medicaid enrollees. RESULTS: In patients using oral glucocorticoids, the estimated relative risk for development of hyperglycemia requiring treatment was 2.23 (95% confidence interval, 1.92 to 2.59) as compared with nonusers. Risk increased with increasing average daily steroid dose, in hydrocortisone-equivalent milligrams; the odds ratio was 1.77 for 1 to 39 mg/d, 3.02 for 40 to 79 mg/d, 5.82 for 80 to 119 mg/d, and 10.34 for 120 mg/d or more. The estimated effects persisted after adjustment for a variety of potentially confounding demographic, health service utilization, and medication use variables. CONCLUSION: The findings of this population-based study quantify the risk of developing hyperglycemia requiring hypoglycemic therapy after oral glucocorticoid use. The magnitude of risk increases substantially with increasing glucocorticoid dose. These findings demonstrate the utility of large-scale health claims databases in defining the risk of important adverse drug effects.

Frequency of inclusion of patients with cardiogenic shock in trials of thrombolytic therapy.

Nananda F. Col — Mon, 02 Nov 2009 11:18:01 PST

The purpose of this study was to determine the extent to which patients with cardiogenic shock have participated in trials of thrombolytic therapy, to examine factors associated with their exclusion from these trials, and to summarize data on the efficacy of thrombolysis in these patients. Previous publications were searched for all randomized, controlled studies involving the use of thrombolytic medications used in the treatment of acute myocardial infarction. Data were abstracted for year of trial publication, performance location, sample size, maximal allowable delay between symptom onset and treatment, and exclusion criteria. Of the 94 trials included in the analysis, 22% included patients with cardiogenic shock, 37% excluded them, and the remainder contained no information on their inclusion or exclusion. Only 2 trials provided data on the efficacy of thrombolytic therapy in patients with cardiogenic shock. Multivariate analysis revealed that studies conducted exclusively in the U.S. were significantly more likely to exclude patients in cardiogenic shock than those conducted outside of the U.S., as were studies that excluded patients with a previous myocardial infarction, studies published more recently, and smaller trials. Patients with cardiogenic shock have frequently been excluded from clinical trials of thrombolytic agents. As a result, data on the efficacy of thrombolytic agents in these patients is extremely limited.

A study of manufacturer-supported trials of nonsteroidal anti-inflammatory drugs in the treatment of arthritis.

Paula A. Rochon — Mon, 02 Nov 2009 11:17:59 PST

BACKGROUND: To study the relation between reported drug performance in published trials and support of the trials by the manufacturer of the drug under evaluation, we studied a sample of trials of nonsteroidal anti-inflammatory drugs (NSAIDs) used in the treatment of arthritis. METHODS: All randomized control trials of NSAIDs published between September 1987 and May 1990 identified by MEDLINE were reviewed. If an article met the following criteria (n = 61), it was selected: trials involving adult patients with osteoarthritis or rheumatoid arthritis (n = 180), use of nonsalicylate NSAIDs marketed in the United States (n = 101), randomized control trial (n = 81), duration of the trial 4 or more days (n = 78), and use of an efficacy outcome measure (n = 61). Reviewers, "blinded" to manufacturer status, evaluated the narrative interpretation of results and extracted numeric data on efficacy and toxicity. Manufacturer-associated trials were defined as those that acknowledged an association with a pharmaceutical manufacturer. Because of the scarcity of non-manufacturer-associated trials (n = 9), we report only on the manufacturer-associated articles. RESULTS: Fifty-two publications (85.2%) representing 56 trials were associated with a manufacturer. The manufacturer-associated drug was reported as comparable with (71.4%) or superior to (28.6%) the comparison drug in all 56 trials. These narrative claims of superiority were usually justified with trial data. Of the trials identifying one drug as less toxic (n = 22), the manufacturer-associated drug's safety was reported as superior to the comparison drug in 86.4% of cases. Justification for the narrative interpretation of the trial findings regarding less toxicity was provided in only 12 (54.5%) of 22 trials. CONCLUSION: The manufacturer-associated NSAID is almost always reported as being equal or superior in efficacy and toxicity to the comparison drug. These claims of superiority, especially in regard to side effect profiles, are often not supported by trial data. These data raise concerns about selective publication or biased interpretation of results in manufacturer-associated trials.

Noncompliance with congestive heart failure therapy in the elderly.

Mark Monane — Mon, 02 Nov 2009 11:17:58 PST

BACKGROUND: Noncompliance with long-term medication regimens, such as those employed in the treatment of congestive heart failure (CHF), has been found to be approximately 50%. However, no evaluation has been performed on a population-based cohort of elderly patients beginning the use of digoxin and followed up longitudinally for an extended observation period. METHODS: To study patterns of medication compliance, we conducted a retrospective follow-up of 7247 outpatients aged 65 to 99 years newly prescribed digoxin between 1981 and 1991, with the use of the complete prescription claims file of the New Jersey Medicaid program. Noncompliance was measured in terms of the number of days during the 12-month period after an initial digoxin prescription in which no CHF medication was available to the patient. RESULTS: Patients started on a regimen of digoxin were without digoxin or any other common alternative CHF drug for an average of 111 of the 365 days of follow-up. Only 10% of the population filled enough prescriptions to have daily CHF medication available for the entire year of follow-up. Compliance rates were higher in patients over 85 years of age, women, those taking multiple medications, and those with hospital or nursing home stays before the initiation of therapy. CONCLUSIONS: A large proportion of patients who begin digoxin therapy end CHF therapy or consume substantially less medication than expected in the first year of therapy. Such high rates of cessation could represent an important impediment to effective CHF therapy.

Controversies surrounding the use of beta-blockers in older patients with cardiovascular disease.

R. W. Jansen — Mon, 02 Nov 2009 11:17:56 PST

Reduction of bacteriuria and pyuria after ingestion of cranberry juice.

Jerry Avorn — Mon, 02 Nov 2009 11:17:54 PST

OBJECTIVE--To determine the effect of regular intake of cranberry juice beverage on bacteriuria and pyuria in elderly women. DESIGN--Randomized, double-blind, placebo-controlled trial. SUBJECTS--Volunteer sample of 153 elderly women (mean age, 78.5 years). INTERVENTION--Subjects were randomly assigned to consume 300 mL per day of a commercially available standard cranberry beverage or a specially prepared synthetic placebo drink that was indistinguishable in taste, appearance, and vitamin C content but lacked cranberry content. OUTCOME MEASURES--A baseline urine sample and six clean-voided study urine samples were collected at approximately 1-month intervals and tested quantitatively for bacteriuria and the presence of white blood cells. RESULTS--Subjects randomized to the cranberry beverage had odds of bacteriuria (defined as organisms numbering > or = 10(5)/mL) with pyuria that were only 42% of the odds in the control group (P = .004). Their odds of remaining bacteriuric-pyuric, given that they were bacteriuric-pyuric in the previous month, were only 27% of the odds in the control group (P = .006). CONCLUSIONS--These findings suggest that use of a cranberry beverage reduces the frequency of bacteriuria with pyuria in older women. Prevalent beliefs about the effects of cranberry juice on the urinary tract may have microbiologic justification.

Evaluating the quality of articles published in journal supplements compared with the quality of those published in the parent journal.

Paula A. Rochon — Mon, 02 Nov 2009 11:17:52 PST

OBJECTIVES--To determine the relationship between the quality of articles and whether they were published in a supplement or in the parent journal. DATA SOURCES AND STUDY SELECTION--All randomized control trials of drug therapies in adults published in the American Journal of Cardiology, the American Journal of Medicine and the American Heart Journal from January 1990 and obtained in November 1992 by means of a MEDLINE search. A total of 318 abstracts appeared to meet our inclusion criteria, and these articles were obtained and reviewed in further detail. An additional 76 were excluded. DATA EXTRACTION--Three reviewers who were "blinded" and thus unaware of supplement status independently assessed the quality of each of the remaining 242 articles according to a standard quality scoring system. DATA SYNTHESIS--Overall, 67 (27.7%) of the articles were published in journal supplements. Article quality scores ranged from 4.2% to 87.5%, with a mean (+/- SD) score of 37.2% +/- 13.1%. Quality scores were lower in articles published in journal supplements than in those published in the parent journal (t[240] = 2.61, P = .01). The mean quality score for articles published in journal supplements was 33.6% +/- 12.8% compared with a score of 38.5% +/- 13.1% for articles published in the parent journal. Supplement articles included in their final analysis a smaller proportion of the patients initially randomized (t[75] = 2.8, P = .007). CONCLUSION--Our findings suggest that randomized control trials published in journal supplements are generally of inferior quality compared with articles published in the parent journal. The review process surrounding the publication of journal supplements should be consistent with that of the parent journal.

Suboptimal medication use in the elderly. The tip of the iceberg.

Jerry H. Gurwitz — Mon, 02 Nov 2009 11:17:48 PST

Constipation: assessment and management in an institutionalized elderly population.

Danielle Harari — Fri, 30 Oct 2009 12:04:57 PDT

OBJECTIVES: To examine prescribing and utilization patterns of laxatives, stool softeners, and enemas in a large, long-term care facility, to compare self-reports of constipation with specific, bowel-related symptoms in residents of this facility, and to examine concordance between bowel symptoms reported by residents and the assessments of the nursing staff. DESIGN: Cross-sectional study. SETTING AND SUBJECTS: All individuals residing in an academically oriented long-term care facility in the United States for at least 1 month (n = 694). MEASUREMENTS: Clinical, functional, and medication data were abstracted from the medical and nursing records. Individual interviews regarding bowel-related symptoms were conducted with all able participants (n = 456 (66%)) and their respective primary nurses, and concordance was determined. The study definition of symptom-specific constipation was no more than 2 bowel movements per week and/or straining on more than 1 in 4 bowel movements. RESULTS: Fifty percent (n = 367) of all residents used at least 1 daily laxative, stool softener or enema during a 1-month study period. Over half of all laxative users (n = 200) took more than 60 doses per month. Stool softeners were most commonly prescribed, followed by saline laxatives, stimulant laxatives, hyperosmolar laxatives, and bulk laxatives. Forty-seven percent (n = 213) of the 456 interview responders reported constipation ("self-reporters"), but only 62% of self-reporters met the study criteria for symptom-specific constipation. Concordance between resident's and nurse's report regarding specific bowel symptoms was only fair to slight (kappa 0.12-0.38). Self-reporters of constipation took almost twice as many laxatives, stool softeners, and enemas as residents who did not report constipation.

Initiation of antihypertensive treatment during nonsteroidal anti-inflammatory drug therapy.

Jerry H. Gurwitz — Fri, 30 Oct 2009 12:04:55 PDT

OBJECTIVE--To determine whether there is an increased risk for the initiation of antihypertensive therapy in older persons prescribed nonaspirin, nonsteroidal anti-inflammatory drugs (NSAIDs). DESIGN--Case-control study. SETTING--New Jersey Medicaid program. PATIENTS--Medicaid enrollees aged 65 years and older. The 9411 case patients were newly started on an antihypertensive medication between November 1981 and February 1990. A similar number of controls were randomly selected among other enrollees. MAIN OUTCOME MEASURES--We used logistic regression to determine the odds ratio for the initiation of antihypertensive therapy in patients using NSAIDs relative to nonusers, after adjusting for age, sex, race, nursing home residence, number of prescriptions filled, intensity of physician utilization, and days hospitalized. RESULTS--The adjusted odds ratio for the initiation of antihypertensive therapy for recent NSAID users compared with nonusers was 1.66 (95% confidence interval, 1.54 to 1.80). The odds ratio increased with increasing daily NSAID dose: the adjusted odds ratio for users of low average daily doses relative to nonusers was 1.55 (95% CI, 1.38 to 1.74), that for medium-dose users was 1.64 (95% CI, 1.44 to 1.87), and that for high-dose users was 1.82 (95% CI, 1.62 to 2.05). CONCLUSIONS--Use of NSAIDs may increase the risk for initiation of antihypertensive therapy in older persons. Given the high prevalence of NSAID use by elderly persons, this association may have important public health implications for the management of hypertension in the older population.

Collaborative Cross-Institutional Model for Faculty and Librarians Teaching Evidence-Based Practice: A Future Fusion Recipe?

Irena Bond — Fri, 30 Oct 2009 11:03:38 PDT

Poster presented at: What's Cooking? A Taste of the Future 2009 NAHSL Annual Meeting Samoset Resort, October 25-27, Rockport, ME This poster describes the development of a novel cross-institutional collaboration between librarians and faculty from a pharmacy school and a medical school to enhance the teaching of Evidence-Based Practice (EBP) in each other's school. Specifically, it focuses on the librarians' active role in bringing shared cross-institutional and cross-disciplinary expertise to the table. Collaboration initiatives described include the joint development of EBP educational modules, EBP pharmacotherapy case studies, EBP Pharmacology elective course, formal and informal meetings, campus visits, and teaching observations. The poster provides a roadmap of starting such collaboration. In addition, it highlights the value of building strategic relationships between faculty and librarians across institutions to share expertise and teaching responsibility to advance student learning.