203 research outputs found

    Study of cosolvent-induced α-chymotrypsin fibrillogenesis: Does protein surface hydrophobicity trigger early stages of aggregation reaction?

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    The misfolding of specific proteins is often associated with their assembly into fibrillar aggregates, commonly termed amyloid fibrils. Despite the many efforts expended to characterize amyloid formation in vitro, there is no deep knowledge about the environment (in which aggregation occurs) as well as mechanism of this type of protein aggregation. Alpha-chymotrypsin was recently driven toward amyloid aggregation by the addition of intermediate concentrations of trifluoroethanol. In the present study, approaches such as turbidimetric, thermodynamic, intrinsic fluorescence and quenching studies as well as chemical modification have been successfully used to elucidate the underlying role of hydrophobic interactions (involved in early stages of amyloid formation) in α-chymotrypsin-based experimental system. © 2009 Springer Science+Business Media, LLC

    Quantifying the relative roles of selective and neutral processes in defining eukaryotic microbial communities

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    We have a limited understanding of the relative contributions of different processes that regulate microbial communities, which are crucial components of both natural and agricultural ecosystems. The contributions of selective and neutral processes in defining community composition are often confounded in field studies because as one moves through space, environments also change. Managed ecosystems provide an excellent opportunity to control for this and evaluate the relative strength of these processes by minimising differences between comparable niches separated at different geographic scales. We use next-generation sequencing to characterize the variance in fungal communities inhabiting adjacent fruit, soil and bark in comparable vineyards across 1000 kms in New Zealand. By compartmentalizing community variation, we reveal that niche explains at least four times more community variance than geographic location. We go beyond merely demonstrating that different communities are found in both different niches and locations by quantifying the forces that define these patterns. Overall, selection unsurprisingly predominantly shapes these microbial communities, but we show the balance of neutral processes also have a significant role in defining community assemblage in eukaryotic microbes

    Immediate versus staged revascularisation of non-culprit arteries in patients with acute coronary syndrome: a systematic review and meta-analysis

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    Although there is robust evidence that revascularisation of non-culprit vessels should be pursued in patients presenting with an acute coronary syndrome (ACS) and multivessel coronary artery disease (MVD), the optimal timing of complete revascularisation remains disputed. In this systematic review and meta-analysis our results suggest that outcomes are comparable for immediate and staged complete revascularisation in patients with ACS and MVD. However, evidence from randomised controlled trials remains scarce and cautious interpretation of these results is recommended. More non-biased evidence is necessary to aid future decision making on the optimal timing of complete revascularisation

    The risk of child and adolescent overweight is related to types of food consumed

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    <p>Abstract</p> <p>Background/Aims</p> <p>To investigate the association between the risk of overweight and the consumption of food groups in children and adolescents.</p> <p>Methods</p> <p>We studied 1764 healthy children and adolescents (age 6-19y) attending 16 Seventh-Day Adventist schools and 13 public schools using a 106-item non-quantitative food frequency questionnaire from the late 1980 Child-Adolescent Blood Pressure Study. Logistic regression models were used to compute the risk of overweight according to consumption of grains, nuts, vegetables, fruits, meats/fish/eggs, dairy, and, low nutrient-dense foods (LNDF).</p> <p>Results</p> <p>The frequency of consumption of grains, nuts, vegetables and LNDF were inversely related to the risk of being overweight and dairy increased the risk. Specifically, the odds ratio (95% CI) for children in the highest quartile or tertile of consumption compared with the lowest quartile or tertile were as follows: grains 0.59(0.41-0.83); nuts 0.60(0.43-0.85); vegetables 0.67(0.48-0.94); LNDF 0.43(0.29-0.63); and, dairy 1.36(0.97, 1.92).</p> <p>Conclusion</p> <p>The regular intake of specific plant foods may prevent overweight among children and adolescents.</p

    Idiopathic sclerosing mesenteritis in paediatrics: Report of a successfully treated case and a review of literature

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    A 6 year old female with symptoms of small bowel obstruction underwent an exploratory laparotomy which revealed widespread evidence of inflammatory fibrotic adhesions involving the jejunal mesentery. In view of persistent growth failure, chronic anaemia, elevated acute phase reactants and imaging evidence of a diffuse progressive inflammatory process, the child was treated with corticosteroids and methotrexate with complete response. The literature on juvenile idiopathic sclerosing mesenteritis has been reviewed

    Prognostic Impact of Nutritional Status After Transcatheter Edge-to-Edge Mitral Valve Repair: The MIVNUT Registry

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    Background Malnutrition is associated with poor prognosis in several cardiovascular diseases. However, its prognostic impact in patients undergoing transcatheter edge-to-edge mitral valve repair (TEER) is not well known. This study sought to assess the prevalence, clinical associations, and prognostic consequences of malnutrition in patients undergoing TEER. Methods and Results A total of 892 patients undergoing TEER from the international MIVNUT (Mitral Valve Repair and Nutritional Status) registry were studied. Malnutrition status was assessed with the Controlling Nutritional Status score. The association of nutritional status with mortality was analyzed with multivariable Cox regression models, whereas the association with heart failure admission was assessed by Fine-Gray models, with death as a competing risk. According to the Controlling Nutritional Status score, 74.4% of patients with TEER had any degree of malnutrition at the time of TEER (75.1% in patients with body mass index <25?kg/m2, 72.1% in those with body mass index ?25?kg/m2). However, only 20% had moderate-severe malnutrition. TEER was successful in most of patients (94.2%). During a median follow-up of 1.6?years (interquartile range, 0.6-3.0), 267 (29.9%) patients died and 256 patients (28.7%) were admitted for heart failure after TEER. Compared with normal nutritional status moderate-severe malnutrition resulted a strong predictor of mortality (adjusted hazard ratio [HR], 2.1 [95% CI, 1.1-2.4]; P<0.001) and heart failure admission (adjusted subdistribution HR, 1.6 [95% CI, 1.1-2.4]; P=0.015). Conclusions Malnutrition is common among patients submitted to TEER, and moderate-severe malnutrition is strongly associated with increased mortality and heart failure readmission. Assessment of nutritional status in these patients may help to improve risk stratification

    Clinical outcomes of state-of-the-art percutaneous coronary revascularization in patients with de novo three vessel disease : 1-year results of the SYNTAX II study

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    Contains fulltext : 182263.pdf (Publisher’s version ) (Open Access)Aims: To investigate if recent technical and procedural developments in percutaneous coronary intervention (PCI) significantly influence outcomes in appropriately selected patients with three-vessel (3VD) coronary artery disease. Methods and results: The SYNTAX II study is a multicenter, all-comers, open-label, single arm study that investigated the impact of a contemporary PCI strategy on clinical outcomes in patients with 3VD in 22 centres from four European countries. The SYNTAX-II strategy includes: heart team decision-making utilizing the SYNTAX Score II (a clinical tool combining anatomical and clinical factors), coronary physiology guided revascularisation, implantation of thin strut bioresorbable-polymer drug-eluting stents, intravascular ultrasound (IVUS) guided stent implantation, contemporary chronic total occlusion revascularisation techniques and guideline-directed medical therapy. The rate of major adverse cardiac and cerebrovascular events (MACCE [composite of all-cause death, cerebrovascular event, any myocardial infarction and any revascularisation]) at one year was compared to a predefined PCI cohort from the original SYNTAX-I trial selected on the basis of equipoise 4-year mortality between CABG and PCI. As an exploratory endpoint, comparisons were made with the historical CABG cohort of the original SYNTAX-I trial. Overall 708 patients were screened and discussed within the heart team; 454 patients were deemed appropriate to undergo PCI. At one year, the SYNTAX-II strategy was superior to the equipoise-derived SYNTAX-I PCI cohort (MACCE SYNTAX-II 10.6% vs. SYNTAX-I 17.4%; HR 0.58, 95% CI 0.39-0.85, P = 0.006). This difference was driven by a significant reduction in the incidence of MI (HR 0.27, 95% CI 0.11-0.70, P = 0.007) and revascularisation (HR 0.57, 95% CI 0.37-0.9, P = 0.015). Rates of all-cause death (HR 0.69, 95% CI 0.27-1.73, P = 0.43) and stroke (HR 0.69, 95% CI 0.10-4.89, P = 0.71) were similar. The rate of definite stent thrombosis was significantly lower in SYNTAX-II (HR 0.26, 95% CI 0.07-0.97, P = 0.045). Conclusion: At one year, clinical outcomes with the SYNTAX-II strategy were associated with improved clinical results compared to the PCI performed in comparable patients from the original SYNTAX-I trial. Longer term follow-up is awaited and a randomized clinical trial with contemporary CABG is warranted. ClinicalTrials.gov Identifier: NCT02015832

    Plasma Hormones Facilitated the Hypermotility of the Colon in a Chronic Stress Rat Model

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    Objective: To study the relationship between brain-gut peptides, gastrointestinal hormones and altered motility in a rat model of repetitive water avoidance stress (WAS), which mimics the irritable bowel syndrome (IBS). Methods: Male Wistar rats were submitted daily to 1-h of water avoidance stress (WAS) or sham WAS (SWAS) for 10 consecutive days. Plasma hormones were determined using Enzyme Immunoassay Kits. Proximal colonic smooth muscle (PCSM) contractions were studied in an organ bath system. PCSM cells were isolated by enzymatic digestion and IKv and IBKca were recorded by the patch-clamp technique. Results: The number of fecal pellets during 1 h of acute restraint stress and the plasma hormones levels of substance P (SP), thyrotropin-releasing hormone (TRH), motilin (MTL), and cholecystokinin (CCK) in WAS rats were significantly increased compared with SWAS rats, whereas vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and corticotropin releasing hormone (CRH) in WAS rats were not significantly changed and peptide YY (PYY) in WAS rats was significantly decreased. Likewise, the amplitudes of spontaneous contractions of PCSM in WAS rats were significantly increased comparing with SWAS rats. The plasma of WAS rats (100 ml) decreased the amplitude of spontaneous contractions of controls. The IKv and IBKCa of PCSMs were significantly decreased in WAS rats compared with SWAS rats and the plasma of WAS rats (100 ml) increased the amplitude of IKv and IBKCa in normal rats
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