170 research outputs found

    Key interaction patterns in proteins revealed by cluster expansion of the partition function

    Full text link
    The native conformation of structured proteins is stabilized by a complex network of interactions. We analyzed the elementary patterns that constitute such network and ranked them according to their importance in shaping protein sequence design. To achieve this goal, we employed a cluster expansion of the partition function in the space of sequences and evaluated numerically the statistical importance of each cluster. An important feature of this procedure is that it is applied to a dense, finite system. We found that patterns that contribute most to the partition function are cycles with even numbers of nodes, while cliques are typically detrimental. Each cluster also gives a contribute to the sequence entropy, which is a measure of the evolutionary designability of a fold. We compared the entropies associated with different interaction patterns to their abundances in the native structures of real proteins

    Hepatic vein pressure determination and phlebography in the evaluation of portal hypertension

    Get PDF
    Click on the link to view

    MORPHOLOGICAL AND BIOMECHANICAL CORRELATION IN THE TENNIS ELBOW

    Get PDF
    With the definition of 'Tennis Elbow' are rubricated a series of pathologies which recognize a common origin in a damage on a level of the myotendon jointing apparatus. A decodification in biochemical molecular key of the jointing apparatus consents to identify a series of microstructures which develop specific functions of a connection between the motory unity and the tendon system. These formations ty ambient such as the one assured by proteoglicanic matrix in which perform the nervous formations wich are appointed to the peripheric control of the rnyotendon jointing. The morphological research led on a level of the myotendon jointings in normal conditions and in the course of insertional pathologia, has displayed howat an insertional level, it takes place deep structural changes characterized by progressive loss of the visco-elasticity . These dates have been put in relation to study of the elbow and wrist joints, in normal conditions and in course of 'tennis elbow'. In particular it has been inquired, in isokinetic, the relation of force of / the 'motor muscles' which control the motory unities of the elbow and wrist joints. In has been observed significative alteration of case control in the peak torque ratio (%) of the an d flex muscles of the wrist (80 vs 40) in the relation of pronators/supinators (138 vs 88). The results of this study suggest how at the base of “tennis elbow' there are biological and biomechanical conditions which determine the arising of pathologia, they condition the evolution and constitute the potential 'target' of the therapy

    The Impact of L-NAME and L-arginine Chronic Toxicity Induced Lesions on Ascites – Pulmonary Hypertension Syndrome Development in Broiler Chickens

    Get PDF
    The impact of L-arginine (LA), a precursor for synthesis of nitric oxide (NO), and N-w -nitro-L-arginine methyl ester (L-NAME, LN), a non-selective inhibitor of the enzyme producing nitric oxide (nitric oxide synthase; NOS) chronic toxicity induced lesions on Ascites – Pulmonary hypertension syndrome (PHS) development was investigated in 140 one-day- -old male broiler chickens (ROSS) during the first 5 weeks of life. Every second day the animals were treated intraperitoneally (ip) with L-NAME (10 mg/kg of body weight; BW), L-arginine (100 mg/kg BW), L-arginine and L-NAME in combination (100 mg/kg BW and 10 mg/kg BW, respectively), and with physiological saline (0.90% w/v of NaCl; 0.5 mL/kg BW). Seven birds from each group were euthanized every week. The histopathological examination of the heart, the liver, the lungs, the blood vessels and the lymphoid organs, was performed. Also the organ index values were determined. At the end of the experiment the pre-ascitic condition or ascites – PHS was confirmed in five dead animals in the L-NAME-treated group. In the same group the edema was the most prominent histopathological change confirmed in the heart and in the lungs of the sacrificed chickens. In L-arginine-treated group the congestion and the haemorrhages were the striking changes in the same organs with the highest degree in the last two weeks of trial. While the focal disruption of myocardiofibriole and hepatocytes were predominant lesions in L-NAME-treated chickens (5thand 4th weeks, respectively), in L-NAME/L-arginine-treated group only the mild focal myocardial degeneration was seen. According to the most of the results of present investigation, it was concluded that the consecutive treatment with L-NAME provoked ascites – PHS, while L-arginine has protective effect in this animal model of disease

    ADAMTS1 alters blood vessel morphology and TSP1 levels in LNCaP and LNCaP-19 prostate tumors

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Decreased expression of the angiogenesis inhibitor ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif, 1) has previously been reported during prostate cancer progression. The aim of this study was to investigate the function of ADAMTS1 in prostate tumors.</p> <p>Methods</p> <p>ADAMTS1 was downregulated by shRNA technology in the human prostate cancer cell line LNCaP (androgen-dependent), originally expressing ADAMTS1, and was upregulated by transfection in its subline LNCaP-19 (androgen-independent), expressing low levels of ADAMTS1. Cells were implanted subcutaneously in nude mice and tumor growth, microvessel density (MVD), blood vessel morphology, pericyte coverage and thrombospondin 1 (TSP1) were studied in the tumor xenografts.</p> <p>Results</p> <p>Modified expression of ADAMTS1 resulted in altered blood vessel morphology in the tumors. Low expression levels of ADAMTS1 were associated with small diameter blood vessels both in LNCaP and LNCaP-19 tumors, while high levels of ADAMTS1 were associated with larger vessels. In addition, TSP1 levels in the tumor xenografts were inversely related to ADAMTS1 expression. MVD and pericyte coverage were not affected. Moreover, upregulation of ADAMTS1 inhibited tumor growth of LNCaP-19, as evidenced by delayed tumor establishment. In contrast, downregulation of ADAMTS1 in LNCaP resulted in reduced tumor growth rate.</p> <p>Conclusions</p> <p>The present study demonstrates that ADAMTS1 is an important regulatory factor of angiogenesis and tumor growth in prostate tumors, where modified ADAMTS1 expression resulted in markedly changed blood vessel morphology, possibly related to altered TSP1 levels.</p

    Repositioning of the global epicentre of non-optimal cholesterol

    Get PDF
    High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe

    Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

    Get PDF
    Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

    Get PDF
    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe
    corecore