66 research outputs found
Structure and Stability of the Spinach Aquaporin SoPIP2;1 in Detergent Micelles and Lipid Membranes
Background: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. Methodology/Principal Finding: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein solubilized with octyl-beta-D-glucopyranoside (OG) or reconstituted into lipid membranes formed by E. coli lipids, diphytanoylphosphatidylcholine (DPhPC), or reconstituted into lipid membranes formed from mixtures of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylserine (POPS), and ergosterol. Generally, SoPIP2;1 secondary structure was found to be predominantly a-helical in accordance with crystallographic data. The protein has a high thermal structural stability in detergent solutions, with an irreversible thermal unfolding occurring at a melting temperature of 58 degrees C. Incorporation of the protein into lipid membranes increases the structural stability as evidenced by an increased melting temperature of up to 70 degrees C. Conclusion/Significance: The results of this study provide insights into SoPIP2;1 stability in various host membranes and suggest suitable choices of detergent and lipid composition for reconstitution of SoPIP2;1 into biomimetic membranes for biotechnological applications
Tobacco use induces anti-apoptotic, proliferative patterns of gene expression in circulating leukocytes of Caucasian males
Abstract Background Strong epidemiologic evidence correlates tobacco use with a variety of serious adverse health effects, but the biological mechanisms that produce these effects remain elusive. Results We analyzed gene transcription data to identify expression spectra related to tobacco use in circulating leukocytes of 67 Caucasian male subjects. Levels of cotinine, a nicotine metabolite, were used as a surrogate marker for tobacco exposure. Significance Analysis of Microarray and Gene Set Analysis identified 109 genes in 16 gene sets whose transcription levels were differentially regulated by nicotine exposure. We subsequently analyzed this gene set by hyperclustering, a technique that allows the data to be clustered by both expression ratio and gene annotation (e.g. Gene Ontologies). Conclusion Our results demonstrate that tobacco use affects transcription of groups of genes that are involved in proliferation and apoptosis in circulating leukocytes. These transcriptional effects include a repertoire of transcriptional changes likely to increase the incidence of neoplasia through an altered expression of genes associated with transcription and signaling, interferon responses and repression of apoptotic pathways
A Metagenomic Approach to Characterization of the Vaginal Microbiome Signature in Pregnancy
While current major national research efforts (i.e., the NIH Human Microbiome Project) will enable comprehensive metagenomic characterization of the adult human microbiota, how and when these diverse microbial communities take up residence in the host and during reproductive life are unexplored at a population level. Because microbial abundance and diversity might differ in pregnancy, we sought to generate comparative metagenomic signatures across gestational age strata. DNA was isolated from the vagina (introitus, posterior fornix, midvagina) and the V5V3 region of bacterial 16S rRNA genes were sequenced (454FLX Titanium platform). Sixty-eight samples from 24 healthy gravidae (18 to 40 confirmed weeks) were compared with 301 non-pregnant controls (60 subjects). Generated sequence data were quality filtered, taxonomically binned, normalized, and organized by phylogeny and into operational taxonomic units (OTU); principal coordinates analysis (PCoA) of the resultant beta diversity measures were used for visualization and analysis in association with sample clinical metadata. Altogether, 1.4 gigabytes of data containing >2.5 million reads (averaging 6,837 sequences/sample of 493 nt in length) were generated for computational analyses. Although gravidae were not excluded by virtue of a posterior fornix pH >4.5 at the time of screening, unique vaginal microbiome signature encompassing several specific OTUs and higher-level clades was nevertheless observed and confirmed using a combination of phylogenetic, non-phylogenetic, supervised, and unsupervised approaches. Both overall diversity and richness were reduced in pregnancy, with dominance of Lactobacillus species (L. iners crispatus, jensenii and johnsonii, and the orders Lactobacillales (and Lactobacillaceae family), Clostridiales, Bacteroidales, and Actinomycetales. This intergroup comparison using rigorous standardized sampling protocols and analytical methodologies provides robust initial evidence that the vaginal microbial 16S rRNA gene catalogue uniquely differs in pregnancy, with variance of taxa across vaginal subsite and gestational age
A randomised controlled trial of compression therapies for the treatment of venous leg ulcers (VenUS 6) : study protocol for a pragmatic, multicentre, parallel group, three arm randomised controlled trial
Background Venous leg ulcer(s), are common, recurring, open wounds on the lower leg, resulting from diseased or damaged leg veins impairing blood flow. Wound healing is the primary treatment aim for venous leg ulceration, alongside management of pain, wound exudate and infection. Full (high) compression therapy delivering 40mmHg of pressure at the ankle is the recommended first line treatment for venous leg ulcers. There are several different forms of compression therapy available including wraps, two-layer hosiery, and two-layer or four-layer bandages. There is good evidence for the clinical and cost effectiveness of four-layer bandage and two-layer hosiery but more limited evidence for other treatments (two-layer bandage and compression wraps). Robust evidence is required to compare clinical and cost effectiveness of these and to investigate which is the best compression treatment for reducing time to healing of venous leg ulcers whilst offering value for money. VenUS 6 will therefore investigate the clinical and cost effectiveness of evidence-based compression, two-layer bandage and compression wraps for time to healing of venous leg ulcers. Methods VenUS 6 is a pragmatic, multi-centre, three arm, parallel group, randomised controlled trial. Adult patients with a venous leg ulcer will be randomised to receive 1) compression wraps, 2) two-layer bandage or 3) evidence-based compression (two-layer hosiery or four-layer bandage). Participants will followed up for between 4 and 12 months. The primary outcome will be time to healing (full epithelial cover in absence of a scab) in days since randomisation. Secondary outcomes will include key clinical events (e.g., healing of the reference leg; ulcer recurrence; ulcer/skin deterioration, amputation, admission/discharge, surgery to close/remove incompetent superficial veins, infection, or death), treatment changes, adherence and ease of use, ulcer related pain, health-related quality of life and resource use. Discussion VenUS 6 will provide robust evidence on the clinical and cost-effectiveness of the different forms of compression therapies for venous leg ulceration. VenUS 6 opened to recruitment in January 2021 and is currently recruiting across 30 participating centres. Clinical Trial Registry: ISRCTN 67321719 (https://doi.org/10.1186/ISRCTN67321719). Prospectively Registered: 14.09.202
Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study
Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life
Diffusion and Adoption of Oat NARC Variety in Rainfed Area, Pakistan
The present study was planned to estimate the extent of diffusion (spread) and adoption of fodder variety Oat NARC developed by Fodder Programe NARC. For this study, farm level information was collected through a formal survey method. For the official survey, an organized and well-structured questionnaire was designed. Mainly oat area of Pothwar region was the study domain. Overall from all selected tehsils, 65 farmers were taken as sample farmers. The findings of present study that includes frequency, descriptive analysis, oat adoption rate and also identified adopters and non adopters. Technical, extension, financial, agro-colmatic and marketing factors constraining adoption of Oat NARC variety also acknowledged. Main objective of this study is to determine the factors affecting the adoption of Oat NARC variety through probit model. Factors like fodder area, soil type, cultivated land , nearest grain market (distance in km), farming experience (years), present level of involvement in farming, availability of credit for purchasing inputs, different varieties you have tested at your farm have positive role in the adoption of Oat NARC variety. The above mentioned variables positively affecting the adoption of oat NARC. This model also show that the area wheat, input market (distance in km), area for local variety, distance from market, lack of knowledge of market information and do you prefer change of varieties grown affects the adoption of Oat negatively
Association of angiotensin-converting enzyme gene dimorphisms with severity of lupus disease.
Angiotensin-converting enzyme (ACE) plays an important role in the development of systemic lupus erythematosus (SLE) because its end-product, angiotensin II, plays an integral role in the regulatory system responsible for endothelial control and vascular tone, systems that are commonly affected in Patients with SLE. Additionally, ACE inhibitors have been shown to retard the progression of SLE and lupus nephritis. Our goal was to investigate whether ACE gene polymorphisms are associated with increasing severity of SLE. We genotyped 39 SLE Patients of varying disease severity from a homogenous Asian population and 79 control subjects for ACE I/D and 2350 G \u3e A dimorphisms. All Patients met the American College of Rheumatology (ACR) criteria for SLE and their disease severity was measured using Systemic Lupus Activity Measure (SLAM). The A allele was found to be associated with increase in severity of SLE with the AA genotype present only in severe disease. No association with SLE in general, compared to healthy subjects, was found with either dimorphism. We also examined the transmission of haplotypes as defined by these polymorphisms. The D and A alleles were found in strong linkage disequilibrium especially in severe SLE. The DA-haplotype was more frequent in severe SLE, than mild to moderate disease. Our findings suggest that DNA sequence variation in the ACE gene influences disease progression and severity of SLE
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