2,005 research outputs found
Contributions of lean mass and fat mass to bone mineral density: a study in postmenopausal women
<p>Abstract</p> <p>Background</p> <p>The relative contribution of lean and fat to the determination of bone mineral density (BMD) in postmenopausal women is a contentious issue. The present study was undertaken to test the hypothesis that lean mass is a better determinant of BMD than fat mass.</p> <p>Methods</p> <p>This cross-sectional study involved 210 postmenopausal women of Vietnamese background, aged between 50 and 85 years, who were randomly sampled from various districts in Ho Chi Minh City (Vietnam). Whole body scans, femoral neck, and lumbar spine BMD were measured by DXA (QDR 4500, Hologic Inc., Waltham, MA). Lean mass (LM) and fat mass (FM) were derived from the whole body scan. Furthermore, lean mass index (LMi) and fat mass index (FMi) were calculated as ratio of LM or FM to body height in metre squared (m<sup>2</sup>).</p> <p>Results</p> <p>In multiple linear regression analysis, both LM and FM were independent and significant predictors of BMD at the spine and femoral neck. Age, lean mass and fat mass collectively explained 33% variance of lumbar spine and 38% variance of femoral neck BMD. Replacing LM and FM by LMi and LMi did not alter the result. In both analyses, the influence of LM or LMi was greater than FM and FMi. Simulation analysis suggested that a study with 1000 individuals has a 78% chance of finding the significant effects of both LM and FM, and a 22% chance of finding LM alone significant, and zero chance of finding the effect of fat mass alone.</p> <p>Conclusions</p> <p>These data suggest that both lean mass and fat mass are important determinants of BMD. For a given body size -- measured either by lean mass or height --women with greater fat mass have greater BMD.</p
Aneurysm of an autologous aorta to right coronary artery reverse saphenous vein graft presenting as a mediastinal mass: a case report
Aneurysmal dilation of saphenous vein grafts is a relatively rare complication of the now common surgical procedure of coronary artery bypass graft (CABG) surgery. The true prevalence of this condition is not clear, however, literature review by Jorgensen et. al. between 1975 and 2002 revealed only 76 published cases. [1] Recent review of literature, utilizing OVID (search terms: saphenous vein, aneurysm, graft, pseudoaneurysm, coronary bypass) suggests a significantly higher prevalence with 14 such cases published in a variety of multinational journals during the period of 2006 to April 2007. The causes of this dramatic increase is likely multifactorial, however, in the author's opinion, likely reflects the increased sophistication and utilization of cross sectional imaging modalities. Regardless of the true prevalence of the condition, there is little debate that the potential for serious morbidity and mortality in this patient population is significant, and that increased detection and discussion of viable therapeutic options is critical. [1] Therefore, we present a case report and discussion of a patient with symptomatic cardiac ischemia, found to have a large saphenous vein graft aneurysm (SVGA) on coronary CTA
Recommended from our members
The combined diabetes and renal control trial (C-DIRECT) - a feasibility randomised controlled trial to evaluate outcomes in multi-morbid patients with diabetes and on dialysis using a mixed methods approach
Background: This cluster randomised controlled trial set out to investigate the feasibility and acceptability of the “Combined Diabetes and Renal Control Trial” (C-DIRECT) intervention, a nurse-led intervention based on motivational interviewing and self-management in patients with coexisting end stage renal diseases and diabetes mellitus (DM ESRD). Its efficacy to improve glycaemic control, as well as psychosocial and self-care outcomes were also evaluated as secondary outcomes.
Methods: An assessor-blinded, clustered randomised-controlled trial was conducted with 44 haemodialysis patients with DM ESRD and ≥ 8% glycated haemoglobin (HbA1c), in dialysis centres across Singapore. Patients were randomised according to dialysis shifts. 20 patients were assigned to intervention and 24 were in usual care. The C-DIRECT intervention consisted of three weekly chair-side sessions delivered by diabetes specialist nurses. Data on recruitment, randomisation, and retention, and secondary outcomes such as clinical endpoints, emotional distress, adherence, and self-management skills measures were obtained at baseline and at 12 weeks follow-up. A qualitative evaluation using interviews was conducted at the end of the trial.
Results: Of the 44 recruited at baseline, 42 patients were evaluated at follow-up. One patient died, and one discontinued the study due to deteriorating health. Recruitment, retention, and acceptability rates of C-DIRECT were generally satisfactory HbA1c levels decreased in both groups, but C-DIRECT had more participants with HbA1c < 8% at follow up compared to usual care. Significant improvements in role limitations due to physical health were noted for C-DIRECT whereas levels remained stable in usual care. No statistically significant differences between groups were observed for other clinical markers and other patient-reported outcomes. There were no adverse effects.
Conclusions: The trial demonstrated satisfactory feasibility. A brief intervention delivered on bedside as part of routine dialysis care showed some benefits in glycaemic control and on QOL domain compared with usual care, although no effect was observed in other secondary outcomes. Further research is needed to design and assess interventions to promote diabetes self-management in socially vulnerable patients
Oxidative damages in tubular epithelial cells in IgA nephropathy: role of crosstalk between angiotensin II and aldosterone
<p>Abstract</p> <p>Background</p> <p>Inhibition of the renin-angiotensin-aldosterone system (RAAS) slows down the progression of chronic renal diseases (CKD) including IgA nephropathy (IgAN). Herein, we studied the pathogenetic roles of aldosterone (Aldo) in IgAN.</p> <p>Methods</p> <p>Human mesangial cells (HMC) was activated with polymeric IgA (pIgA) from IgAN patients and the effects on the expression of RAAS components and TGF-β synthesis examined. To study the roles of RAAS in the glomerulotubular communication, proximal tubular epithelial cells (PTEC) was cultured with conditioned medium from pIgA-activated HMC with eplerenone or PD123319, the associated apoptotic event was measured by the generation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and reactive oxygen species (ROS).</p> <p>Results</p> <p>Polymeric IgA up-regulated the Aldo synthesis and aldosterone synthase expression by HMC. The release of TGF-β by HMC was up-regulated synergistically by AngII and Aldo and this was inhibited by incubation of HMC with losartan plus eplerenone. Cultured PTEC express the mineralocorticoid receptor, but not synthesizing aldosterone. Apoptosis, demonstrated by cleaved PARP expression and caspase 3 activity, was induced in PTEC activated by conditioned medium prepared from HMC cultured with pIgA from IgAN patients. This apoptotic event was associated with increased generation of NADPH oxidase and ROS. Pre-incubation of PTEC with PD123319 and eplerenone achieved complete inhibition of PTEC apoptosis.</p> <p>Conclusions</p> <p>Our data suggest that AngII and Aldo, released by pIgA activated HMC, served as mediators for inducing apoptosis of PTEC in glomerulo-tubular communications. Crosstalk between AngII and Aldo could participate in determining the tubular pathology of IgAN.</p
Impact of PDF uncertainties at large x on heavy boson production
We explore the sensitivity of W and Z boson production in hadronic collisions
to uncertainties in parton distribution functions (PDFs) at large x arising
from uncertainties in nuclear corrections when using deuterium data in global
QCD fits. The W and Z differential cross sections show increasing influence of
nuclear corrections at high boson rapidities, particularly for the d quark,
which is diluted somewhat in the decay lepton rapidity distributions. The
effects of PDF uncertainties on heavy W' and Z' bosons beyond the Standard
Model become progressively more important for larger boson masses or
rapidities, both in p-p collisions at the LHC and in p-pbar scattering at the
Tevatron.Comment: 23 pages, 9 figures; to appear in JHE
Image informatics strategies for deciphering neuronal network connectivity
Brain function relies on an intricate network of highly dynamic neuronal connections that rewires dramatically under the impulse of various external cues and pathological conditions. Among the neuronal structures that show morphologi- cal plasticity are neurites, synapses, dendritic spines and even nuclei. This structural remodelling is directly connected with functional changes such as intercellular com- munication and the associated calcium-bursting behaviour. In vitro cultured neu- ronal networks are valuable models for studying these morpho-functional changes. Owing to the automation and standardisation of both image acquisition and image analysis, it has become possible to extract statistically relevant readout from such networks. Here, we focus on the current state-of-the-art in image informatics that enables quantitative microscopic interrogation of neuronal networks. We describe the major correlates of neuronal connectivity and present workflows for analysing them. Finally, we provide an outlook on the challenges that remain to be addressed, and discuss how imaging algorithms can be extended beyond in vitro imaging studies
Gender effect on clinical features of achalasia: a prospective study
BACKGROUND: Achalasia is a well-characterized esophageal motor disorder but the rarity of the disease limits performing large studies on its demographic and clinical features. METHODS: Prospectively, 213 achalasia patients (110 men and 103 women) were enrolled in the study. The diagnosis established by clinical, radiographic, and endoscopic as well as manometry criteria. All patients underwent a pre-designed clinical evaluation before and within 6 months after the treatment. RESULTS: Solid dysphagia was the most common clinical symptom in men and women. Chest pain was the only symptom which was significantly different between two groups and was more complained by women than men (70.9% vs. 54.5% P value= 0.03). Although the occurrence of chest pain significantly reduced after treatment in both groups (P < 0.001), it was still higher among women (32% vs. 20.9% P value= 0.04). In both sexes, chest pain did not relate to the symptom duration, LES pressure and type of treatment patients received. Also no significant relation was found between chest pain and other symptoms expressed by men and women before and after treatment. Chest pain was less frequently reported by patients over 56 yrs of age in comparison to those less than 56 yrs (p < 0.05). CONCLUSION: It seems that chest pain is the distinct symptom of achalasia which is affected by sex as well as age and does not relate to the duration of illness, LESP and the type of treatment achalasia patients receive
Difficulties in assessing cytomegalovirus-associated gastric perforation in an HIV-infected patient
BACKGROUND: Active Cytomegalovirus (CMV) infection is a common complication in advanced symptomatic Human Immunodeficiency Virus (HIV) infection. CMV-induced intestinal perforations are hard to diagnose and may be observed throughout the gastrointestinal tract. Isolated stomach perforation is exceptional. CASE PRESENTATION: A 47-year-old man was admitted to our intensive care unit with multiorgan failure. Gastrointestinal endoscopic examination showed erythematous gastritis but normal duodenum and colon. CMV blood culture was positive. Histologic examination of a gastric biopsy showed inflammatory infiltrate and immunostaining typical intranuclear CMV inclusion bodies. Concomitant abdominal CT scan disclosed large peripancreatic hypodensities without pneumoperitoneum. The patient died despite supportive therapies and ganciclovir infusion. Postmortem examination showed a 4-cm gastric perforation adhering to the transverse colon and liver, with a thick necrotic inflammatory coating around the pancreas. The whole GI tract, except the stomach, was normal. As other causes, especially Helicobacter pylori infection could be ruled out, a causal relationship between CMV and gastric disease was assumed. CONCLUSION: CMV may be responsible for gastric perforations, with difficulties in assessing the diagnosis. Early diagnosis based on cautious endoscopy and histopathologic examination is needed to make a favorable outcome possible
Simvastatin ameliorates established pulmonary hypertension through a heme oxygenase-1 dependent pathway in rats
<p>Abstract</p> <p>Background</p> <p>Simvastatin has been shown to ameliorate pulmonary hypertension by several mechanisms in experimental animal models. In this study, we hypothesized that the major benefits of simvastatin in pulmonary hypertension occur via the heme oxygenase-1 pathway.</p> <p>Methods</p> <p>Simvastatin (10 mg/kgw/day) was tested in two rat models of pulmonary hypertension (PH): monocrotaline administration and chronic hypoxia. The hemodynamic changes, right heart hypertrophy, HO-1 protein expression, and heme oxygenase (HO) activity in lungs were measured in both models with and without simvastatin treatment. Tin-protoporphyrin (SnPP, 20 μmol/kg w/day), a potent inhibitor of HO activity, was used to confirm the role of HO-1.</p> <p>Results</p> <p>Simvastatin significantly ameliorated pulmonary arterial hypertension from 38.0 ± 2.2 mm Hg to 22.1 ± 1.9 mm Hg in monocrotaline-induced PH (MCT-PH) and from 33.3 ± 0.8 mm Hg to 17.5 ± 2.9 mm Hg in chronic hypoxia-induced PH (CH-PH) rats. The severity of right ventricular hypertrophy was significantly reduced by simvastatin in MCT-PH and CH-PH rats. Co-administration with SnPP abolished the benefits of simvastatin. Simvastatin significantly increased HO-1 protein expression and HO activity in the lungs of rats with PH; however co-administration of SnPP reduced HO-1 activity only. These observations indicate that the simvastatin-induced amelioration of pulmonary hypertension was directly related to the activity of HO-1, rather than its expression.</p> <p>Conclusion</p> <p>This study demonstrated that simvastatin treatment ameliorates established pulmonary hypertension primarily through an HO-1-dependent pathway.</p
Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways
It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers
- …