2,857,881 research outputs found
Replacement of dietary saturated fatty acids by trans fatty acids lowers serum HDL cholesterol and impairs endothelial function in healthy men and women
We tested whether trans fatty acids and saturated fatty acids had different effects on flow-mediated vasodilation (FMD), a risk marker of coronary heart disease (CHD). Consumption of trans fatty acids is related to increased risk of CHD, probably through effects on lipoproteins. Trans fatty acids differ from most saturated fatty acids because they decrease serum high-density lipoprotein (HDL) cholesterol, and this may increase the risk of CHD. We fed 29 volunteers 2 controlled diets in a 2x4-week randomized crossover design. The "Trans-diet" contained 9.2 energy percent of trans fatty acids; these were replaced by saturated fatty acids in the "Sat-diet." Mean serum HDL cholesterol after the Trans-diet was 0.39 mmol/L (14.8 mg/dL), or 21␕ower than after the Sat-diet (95␌I 0.28 to 0.50 mmol/L). Serum low density lipoprotein and triglyceride concentrations were stable. FMD SD was 4.4±2.3fter the Trans-diet and 6.2±3.0fter the Sat-diet (difference -1.8°95␌I -3.2 to -0.4). Replacement of dietary saturated fatty acids by trans fatty acids impaired FMD of the brachial artery, which suggests increased risk of CHD. Further studies are needed to test whether the decrease in serum HDL cholesterol caused the impairment of FMD
Pharmacokinetic study of praziquantel enantiomers and its main metabolite R-trans-4-OH-PZQ in plasma, blood and dried blood spots in Opisthorchis viverrini-infected patients
Praziquantel (PZQ) is the treatment of choice for infections with the liver fluke Opisthorchis viverrini, a major health problem in Southeast Asia. However, pharmacokinetic (PK) studies investigating the disposition of PZQ enantiomers (R- and S-PZQ) and its main metabolite, R-trans-4-OH-PZQ, in diseased patients are lacking. The implementation of a dried blood spot (DBS) sampling technique would ease the performance of PK studies in remote areas without clinical facilities. The aim of the present study is to provide data on the disposition of PZQ enantiomers and R-trans-4-OH-PZQ in opisthorchiasis patients and to validate the use of DBS compared to plasma and blood sampling.; PZQ was administered to nine O. viverrini-infected patients at 3 oral doses of 25 mg/kg in 4 h intervals. Plasma, blood and DBS were simultaneously collected at selected time points from 0 to 24 h post-treatment. PK parameters were determined using non-compartmental analysis. Drug concentrations and areas under the curve (AUC0-24h) measured in the 3 matrices were compared using Bland-Altman analysis. We observed plasma AUC0-24hs of 1.1, 9.0 and 188.7 μg/ml*h and half-lives of 1.1, 3.3 and 6.4 h for R-PZQ, S-PZQ and R-trans-4-OH, respectively. Maximal plasma concentrations (Cmax) of 0.2, 0.9 and 13.9 μg/ml for R-PZQ, S-PQZ and R-trans-4-OH peaked at 7 h for PZQ enantiomers and at 8.7 h for the metabolite. Individual drug concentration measurements and patient AUC0-24hs displayed ratios of blood or DBS versus plasma between 79-94% for R- and S-PZQ, and between 108-122% for R-trans-4-OH.; Pharmacodynamic (PD) in vitro studies on PZQ enantiomers and R-trans-4-OH-PZQ are necessary to be able to correlate PK parameters with efficacy. DBS appears to be a valid alternative to conventional venous sampling for PK studies in PZQ-treated patients
Why Disability Studies Scholars Must Challenge Transmisogyny and Transphobia
We argue the need for coalition between trans and disability studies and activism, and that Disability Studies gives us the tools for this task. Our argument rests upon six facets. First and foremost, we explicitly acknowledge the existence of trans disabled people, arguing that Disability Studies must recognise the diversity of disabled people’s lives. Second, we consider how the homogenisation of womanhood, too often employed in transmisogonist arguments particularly when coming from those claiming to be feminists, harm both non-disabled trans women and cis disabled women. This leads to our third point, that Feminist Disability studies must be anti-reductive, exploring how gendered experiences rest upon other social positions (disability, queerness, race etc.) Fourth, we reflect upon the ways in which Disability Studies and feminism share a struggle for bodily autonomy, and that this should include trans people’s bodily autonomy. Finally, we argue that Trans and Disability Studies and activism share complex and critical relationships with medicine, making Disability and Trans Studies useful allies in the fight for better universal health care. We conclude by calling for our colleagues in Disability Studies to challenge transmisogony and transphobia and that transphobia is not compatible with Disability Studies perspectives
Hepatic stellate cells and parasite-induced liver fibrosis
ABSTRACT: Fibrogenesis is a common feature of many diseases where there is severe insult to the liver. The hepatic stellate cell trans-differentiation into a myofibroblast has been identified as an important event in liver fibrogenesis and has been well investigated over the last few years in a number of liver diseases. The trans-differentiation process can be monitored in vitro by evaluation of biomarkers that are characteristic of normal quiescent hepatic stellate cells or activated myofibroblasts. Two major parasitic diseases associated with liver injury and fibrosis are schistosomiasis and echinococcosis. Recent studies have highlighted a role for activated hepatic stellate cells in both murine and human schistosomiasis as well as demonstrating that schistosome antigens are able to regulate this trans-differentiation process. Study of the hepatic stellate cell and its interaction with parasite-derived antigens may be pivotal in our understanding of the pathology associated with schistosomiasis and other parasitic diseases, including echinococcosis, as well as revealing new information on the trans-differentiation process in this cell type
Genome-wide co-expression analysis in multiple tissues
Expression quantitative trait loci (eQTLs) represent genetic control points of gene expression, and can be categorized as cis- and trans-acting, reflecting local and distant regulation of gene expression respectively. Although there is evidence of co-regulation within clusters of trans-eQTLs, the extent of co-expression patterns and their relationship with the genotypes at eQTLs are not fully understood. We have mapped thousands of cis- and trans-eQTLs in four tissues (fat, kidney, adrenal and left ventricle) in a large panel of rat recombinant inbred (RI) strains. Here we investigate the genome-wide correlation structure in expression levels of eQTL transcripts and underlying genotypes to elucidate the nature of co-regulation within cis- and trans-eQTL datasets. Across the four tissues, we consistently found statistically significant correlations of cis-regulated gene expression to be rare (<0.9% of all pairs tested). Most (>80%) of the observed significant correlations of cis-regulated gene expression are explained by correlation of the underlying genotypes. In comparison, co-expression of trans-regulated gene expression is more common, with significant correlation ranging from 2.9%-14.9% of all pairs of trans-eQTL transcripts. We observed a total of 81 trans-eQTL clusters (hot-spots), defined as consisting of > or =10 eQTLs linked to a common region, with very high levels of correlation between trans-regulated transcripts (77.2-90.2%). Moreover, functional analysis of large trans-eQTL clusters (> or =30 eQTLs) revealed significant functional enrichment among genes comprising 80% of the large clusters. The results of this genome-wide co-expression study show the effects of the eQTL genotypes on the observed patterns of correlation, and suggest that functional relatedness between genes underlying trans-eQTLs is reflected in the degree of co-expression observed in trans-eQTL clusters. Our results demonstrate the power of an integrative, systematic approach to the analysis of a large gene expression dataset to uncover underlying structure, and inform future eQTL studies
Studies on an antifibrinolytic agent trans-AMCHA
Lysis of fibrin was first recognized by MORGAGNI in 1769, observing a liquid blood in a patient of acute death, and the phenomenon was named as fibrinolysis by DASTRE in 1893. In 1937, MACFARLANE recognized in a patient after cholecystectomy that the blood clot was lysed completely in the following morning. Since then, much attention has been paid clinically on fibrinolysis and it has been said to occur in case receiving a large amount of blood transfusion, shock, cancer, obstetric diseases, hemophilia, various drug poisonings, allergic diseases, after irradiation and after the operations of lung, pancreas and prostate. In our department, also, the similar phenomenon was recognized often in association with cardiac surgery using the artificial heart-lung machine, and a difficulty in hemostasis was encountered postoperatively. We have been studying, therefore, on fibrinolysis in open heart surgery.</p
Peierls Instability in Carbon Nanotubes
We present a first-principles study of Peierls distortions in
\emph{trans}-polyacetylene, polyacene, and armchair carbon nanotubes.
Our findings suggest that the ground-state geometries of armchair
carbon nanotubes, with up to 6, exhibit a Peierls distortion as it is found
for \emph{trans}-polyactetylene. In contrast to previous studies in which no
Peierls distortion is found with conventional local and semi-local density
functionals, we use a hybrid functional whose exact-exchange admixture has been
specifically optimized for the problem at hand.Comment: 4 pages, 2 figures, 2 table
Functional Stoichiometry at the Nicotinic Receptor. The Photon Cross Section for Phase 1 Corresponds to Two Bis-Q Molecules per Channel
These experiments examine changes in the agonist-induced conductance
that occur when the agonist-receptor complex is perturbed. Voltage-clamped
Electrophorus electroplaques are exposed to the photoisomerizable agonist
trans-Bis-Q A 1-µs laser flash photoisomerizes some trans-Bis-Q molecules
bound to receptors; because the cis configuration is not an agonist, receptor
channels close within a few hundred microseconds. This effect is called phase 1.
We compare (a) the fraction of channels that close during phase 1 with (b) the
fraction of trans-Bis-Q molecules that undergo trans → cis photoisomerization.
Parameter a is measured as the fractional diminution in voltage-clamp currents
during phase 1. Parameter b is measured by changes in the optical spectra of
Bis-Q solutions caused by flashes . At low flash intensities, a is twice b, which
shows that the channel can be closed by photoisomerizing either of two bound
agonist molecules. Conventional dose-response studies with trans-Bis-Q also give
a Hill coefficient of two. As a partial control for changes in the photochemistry
caused by binding of Bis-Q to receptors, spectral measurements are performed
on the photoisomerizable agonist QBr, covalently bound to solubilized acetylcholine
receptors from Torpedo. The bound and free agonist molecules have the
same photoisomerization properties. These results verify the concept that the
open state of the acetylcholine receptor channel is much more likely to be
associated with the presence of two bound agonist molecules than with a single
such molecule
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Autosomal Dominant Retinal Dystrophies Caused by a Founder Splice Site Mutation, c.828+3A>T, in PRPH2 and Protein Haplotypes in trans as Modifiers.
PurposeWe determined the phenotypic variation, disease progression, and potential modifiers of autosomal dominant retinal dystrophies caused by a splice site founder mutation, c.828+3A>T, in the PRPH2 gene.MethodsA total of 62 individuals (19 families) harboring the PRPH2 c.828+3A>T mutation, had phenotype analysis by fundus appearance, electrophysiology, and visual fields. The PRPH2 haplotypes in trans were sequenced for potential modifying variants and generalized estimating equations (GEE) used for statistical analysis.ResultsSeveral distinct phenotypes caused by the PRPH2 c.828+3A>T mutation were observed and fell into two clinical categories: Group I (N = 44) with mild pattern dystrophies (PD) and Group II (N = 18) with more severe cone-rod dystrophy (CRD), retinitis pigmentosa (RP), and central areolar chorioretinal dystrophy (CACD). The PRPH2 Gln304-Lys310-Asp338 protein haplotype in trans was found in Group I only (29.6% vs. 0%), whereas the Glu304-Lys310-Gly338 haplotype was predominant in Group II (94.4% vs. 70.4%). Generalized estimating equations analysis for PD versus the CRD/CACD/RP phenotypes in individuals over 43 years alone with the PRPH2 haplotypes in trans and age as predictors, adjusted for correlation within families, confirmed a significant effect of haplotype on severity (P = 0.03) with an estimated odds ratio of 7.16 (95% confidence interval [CI] = [2.8, 18.4]).ConclusionsThe PRPH2 c.828+3A>T mutation results in multiple distinct phenotypes likely modified by protein haplotypes in trans; the odds of having the CACD/RP-like phenotype (versus the PD phenotype) are 7.16 times greater with a Glu304-Lys310-Gly338 haplotype in trans. Further functional studies of the modifying haplotypes in trans and PRPH2 splice variants may offer therapeutic targets
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