418 research outputs found
Portfolio-based appraisal: superficial or useful?
This paper outlines the growing role played by performance appraisal within medical regulation, supported by learning portfolios. It investigates if these are superficial or useful tools. In doing so it argues that caution must be exercised in promoting such tools to help modernise medical regulatory frameworks
Interleukin-1 regulates multiple atherogenic mechanisms in response to fat feeding
Background: Atherosclerosis is an inflammatory process that develops in individuals with known risk factors that include hypertension and hyperlipidaemia, influenced by diet. However, the interplay between diet, inflammatory mechanisms and vascular risk factors requires further research. We hypothesised that interleukin-1 (IL-1) signaling in the vessel wall would raise arterial blood pressure and promote atheroma.
Methodology/Principal Findings: Apoe(-/-) and Apoe(-/-)/IL-1R1(-/-) mice were fed high fat diets for 8 weeks, and their blood pressure and atherosclerosis development measured. Apoe(-/-)/IL-R1(-/-) mice had a reduced blood pressure and significantly less atheroma than Apoe(-/-) mice. Selective loss of IL-1 signaling in the vessel wall by bone marrow transplantation also reduced plaque burden (p<0.05). This was associated with an IL-1 mediated loss of endothelium-dependent relaxation and an increase in vessel wall Nox 4. Inhibition of IL-1 restored endothelium-dependent vasodilatation and reduced levels of arterial oxidative stress.
Conclusions/Significance: The IL-1 cytokine system links atherogenic environmental stimuli with arterial inflammation, oxidative stress, increased blood pressure and atherosclerosis. This is the first demonstration that inhibition of a single cytokine can block the rise in blood pressure in response to an environmental stimulus. IL-1 inhibition may have profound beneficial effects on atherogenesis in man
Comparison of pharmacist managed anticoagulation with usual medical care in a family medicine clinic
Background
The beneficial outcomes of oral anticoagulation therapy are dependent upon achieving and maintaining an optimal INR therapeutic range. There is growing evidence that better outcomes are achieved when anticoagulation is managed by a pharmacist with expertise in anticoagulation management rather than usual care by family physicians. This study compared a pharmacist managed anticoagulation program (PC) to usual physician care (UC) in a family medicine clinic.
Methods
A retrospective cohort study was carried out in a family medicine clinic which included a clinical pharmacist. In 2006, the pharmacist assumed anticoagulation management. For a 17-month period, the PC group (n = 112) of patients on warfarin were compared to the UC patients (n = 81) for a similar period prior to 2006. The primary outcome was the percentage of time patients' INR was in the therapeutic range (TTR). Secondary outcomes were the percentage of time in therapeutic range within ± 0.3 units of the recommended range (expanded TTR) and percentage of time the INR was >5.0 or <1.5.
Results
The baseline characteristics were similar between the groups. Fifty-five percent of the PC group was male with a mean age of 67 years; 51% of the UC group was male with a mean age of 71 years. The most common indications for warfarin in both groups were atrial fibrillation, mechanical heart valves and deep vein thrombosis. The TTR was 73% for PC and 65% for UC (p 5 were 0.3% for PC patients and 0.1% for UC (p < 0.0001).
Conclusion
The pharmacist-managed anticoagulation program within a family practice clinic compared to usual care by the physicians achieved significantly better INR control as measured by the percentage of time patients' INR values were kept in both the therapeutic and expanded range. Based on the results of this study, a collaborative family practice clinic using pharmacists and physicians may be an effective model for anticoagulation management with these results verified in future prospective randomized studies
Sarcolemma-localized nNOS is required to maintain activity after mild exercise
Many neuromuscular conditions are characterized by an exaggerated exercise- induced fatigue response that is disproportionate to activity level. This fatigue is not necessarily correlated with greater central or peripheral fatigue in patients(1), and some patients experience severe fatigue without any demonstrable somatic disease(2). Except in myopathies that are due to specific metabolic defects, the mechanism underlying this type of fatigue remains unknown(2). With no treatment available, this form of inactivity is a major determinant of disability(3). Here we show, using mouse models, that this exaggerated fatigue response is distinct from a loss in specific force production by muscle, and that sarcolemma-localized signalling by neuronal nitric oxide synthase ( nNOS) in skeletal muscle is required to maintain activity after mild exercise. We show that nNOS- null mice do not have muscle pathology and have no loss of muscle- specific force after exercise but do display this exaggerated fatigue response to mild exercise. In mouse models of nNOS mislocalization from the sarcolemma, prolonged inactivity was only relieved by pharmacologically enhancing the cGMP signal that results from muscle nNOS activation during the nitric oxide signalling response to mild exercise. Our findings suggest that the mechanism underlying the exaggerated fatigue response to mild exercise is a lack of contraction- induced signalling from sarcolemma- localized nNOS, which decreases cGMP- mediated vasomodulation in the vessels that supply active muscle after mild exercise. Sarcolemmal nNOS staining was decreased in patient biopsies from a large number of distinct myopathies, suggesting a common mechanism of fatigue. Our results suggest that patients with an exaggerated fatigue response to mild exercise would show clinical improvement in response to treatment strategies aimed at improving exercise- induced signalling.Paul D. Wellstone Muscular Dystrophy Cooperative Research Center Grant ; University of Iowa Cardiovascular Interdisciplinary Research ; National Research Service Award ; National Institute of Arthritis and Musculoskeletal and Skin Diseases ; National Institutes of Health ; Senator Paul D. Wellstone Fellowship ; Muscular Dystrophy Association Development Grant ; Howard Hughes Medical InstituteWe thank M. Anderson and M. Henry for comments, and M. M. Kilburg, K. Uppal, B. J. Steinmann and S. Watkins and members of the Campbell laboratory for scientific contributions. This work was supported in part by a Paul D. Wellstone Muscular Dystrophy Cooperative Research Center Grant. Y.M.K. was supported by grants from the University of Iowa Cardiovascular Interdisciplinary Research/ National Research Service Award (NRSA) Fellowship, from an individual NRSA Fellowship from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, from the National Institutes of Health (NIH), and from a Senator Paul D. Wellstone Fellowship. E.P.R. was supported by a Muscular Dystrophy Association Development Grant. R.M.W. was supported by the NIH. K.P.C. is an investigator of the Howard Hughes Medical Institute.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62850/1/nature07414.pd
Characterization of RNase MRP RNA and novel snoRNAs from Giardia intestinalis and Trichomonas vaginalis
<p>Abstract</p> <p>Background</p> <p>Eukaryotic cells possess a complex network of RNA machineries which function in RNA-processing and cellular regulation which includes transcription, translation, silencing, editing and epigenetic control. Studies of model organisms have shown that many ncRNAs of the RNA-infrastructure are highly conserved, but little is known from non-model protists. In this study we have conducted a genome-scale survey of medium-length ncRNAs from the protozoan parasites <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>.</p> <p>Results</p> <p>We have identified the previously 'missing' <it>Giardia </it>RNase MRP RNA, which is a key ribozyme involved in pre-rRNA processing. We have also uncovered 18 new H/ACA box snoRNAs, expanding our knowledge of the H/ACA family of snoRNAs.</p> <p>Conclusions</p> <p>Results indicate that <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>, like their distant multicellular relatives, contain a rich infrastructure of RNA-based processing. From here we can investigate the evolution of RNA processing networks in eukaryotes.</p
SUMOylation of Syntaxin1A regulates presynaptic endocytosis
Neurotransmitter release from the presynaptic terminal is under very precise spatial and temporal control. Following neurotransmitter release, synaptic vesicles are recycled by endocytosis and refilled with neurotransmitter. During the exocytosis event leading to release, SNARE proteins provide most of the mechanical force for membrane fusion. Here, we show one of these proteins, Syntaxin1A, is SUMOylated near its C-terminal transmembrane domain in an activity-dependent manner. Preventing SUMOylation of Syntaxin1A reduces its interaction with other SNARE proteins and disrupts the balance of synaptic vesicle endo/exocytosis, resulting in an increase in endocytosis. These results indicate that SUMOylation regulates the emerging role of Syntaxin1A in vesicle endocytosis, which in turn, modulates neurotransmitter release and synaptic function
Increased Phosphorylation of Vimentin in Noninfiltrative Meningiomas
International audienceBACKGROUND: Tissue invasion or tissue infiltration are clinical behaviors of a poor-prognosis subset of meningiomas. We carried out proteomic analyses of tissue extracts to discover new markers to accurately distinguish between infiltrative and noninfiltrative meningiomas. METHODOLOGY/PRINCIPAL FINDINGS: Protein lysates of 64 different tissue samples (including two brain-invasive and 32 infiltrative tumors) were submitted to SELDI-TOF mass spectrometric analysis. Mass profiles were used to build up both unsupervised and supervised hierarchical clustering. One marker was found at high levels in noninvasive and noninfiltrative tumors and appeared to be a discriminative marker for clustering infiltrative and/or invasive meningiomas versus noninvasive meningiomas in two distinct subsets. Sensitivity and specificity were 86.7% and 100%, respectively. This marker was purified and identified as a multiphosphorylated form of vimentin, a cytoskeletal protein expressed in meningiomas. CONCLUSIONS/SIGNIFICANCE: Specific forms of vimentin can be surrogate molecular indicators of the invasive/infiltrative phenotype in tumors
Antiangiogenic agents in the treatment of recurrent or newly diagnosed glioblastoma: Analysis of single-agent and combined modality approaches
Surgical resection followed by radiotherapy and temozolomide in newly diagnosed glioblastoma can prolong survival, but it is not curative. For patients with disease progression after frontline therapy, there is no standard of care, although further surgery, chemotherapy, and radiotherapy may be used. Antiangiogenic therapies may be appropriate for treating glioblastomas because angiogenesis is critical to tumor growth. In a large, noncomparative phase II trial, bevacizumab was evaluated alone and with irinotecan in patients with recurrent glioblastoma; combination treatment was associated with an estimated 6-month progression-free survival (PFS) rate of 50.3%, a median overall survival of 8.9 months, and a response rate of 37.8%. Single-agent bevacizumab also exceeded the predetermined threshold of activity for salvage chemotherapy (6-month PFS rate, 15%), achieving a 6-month PFS rate of 42.6% (p < 0.0001). On the basis of these results and those from another phase II trial, the US Food and Drug Administration granted accelerated approval of single-agent bevacizumab for the treatment of glioblastoma that has progressed following prior therapy. Potential antiangiogenic agents-such as cilengitide and XL184-also show evidence of single-agent activity in recurrent glioblastoma. Moreover, the use of antiangiogenic agents with radiation at disease progression may improve the therapeutic ratio of single-modality approaches. Overall, these agents appear to be well tolerated, with adverse event profiles similar to those reported in studies of other solid tumors. Further research is needed to determine the role of antiangiogenic therapy in frontline treatment and to identify the optimal schedule and partnering agents for use in combination therapy
Lentivirus-meditated frataxin gene delivery reverses genome instability in Friedreich ataxia patient and mouse model fibroblasts
Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by deficiency of frataxin protein, with the primary sites of pathology being the large sensory neurons of the dorsal root ganglia and the cerebellum. FRDA is also often accompanied by severe cardiomyopathy and diabetes mellitus. Frataxin is important in mitochondrial iron–sulfur cluster (ISC) biogenesis and low-frataxin expression is due to a GAA repeat expansion in intron 1 of the FXN gene. FRDA cells are genomically unstable, with increased levels of reactive oxygen species and sensitivity to oxidative stress. Here we report the identification of elevated levels of DNA double strand breaks (DSBs) in FRDA patient and YG8sR FRDA mouse model fibroblasts compared to normal fibroblasts. Using lentivirus FXN gene delivery to FRDA patient and YG8sR cells, we obtained long-term overexpression of FXN mRNA and frataxin protein levels with reduced DSB levels towards normal. Furthermore, γ-irradiation of FRDA patient and YG8sR cells revealed impaired DSB repair that was recovered on FXN gene transfer. This suggests that frataxin may be involved in DSB repair, either directly by an unknown mechanism, or indirectly via ISC biogenesis for DNA repair enzymes, which may be essential for the prevention of neurodegeneration.Ataxia UK, FARA Australasia and FARA US
- …