2,012 research outputs found
Influence of dietary phytochemicals and microbiota on colon cancer risk.
Colon cancer is the third most commonly diagnosed type of cancer in the United States. Lifestyle and dietary patterns influence colon cancer risk both positively and negatively. Among the dietary factors, several plant-derived compounds have been found to afford colon cancer protection. These compounds potentially influence all aspects of colonic cellular regulation and develop complex interrelationships with the colonic microbiome. Increasing understanding of the role of microorganisms in determining the colonic environment has led to awareness of this important interrelationship among dietary factors and the microbial population. Plant-derived polyphenols are active mediators of cellular events, target key carcinogenic pathways, and modulate colonic microbial populations. In turn, the colonic microorganisms metabolize dietary compounds and mediate cellular events. In addition, the role of estrogen receptors in colon cancer and the importance of dietary components that mediate estrogen receptor-β are increasingly being discovered. Hence, dietary bioactive compounds and the intestinal microbiota create a complex milieu that directly affects the carcinogenic events of the colon. These relationships must be carefully characterized in future research to provide dietary recommendations that will reduce colon cancer risk
Tuberculosis and sexually transmitted infections
To the Editor: Mycobacterium tuberculosis infection is a necessary, but not sufficient, cause of tuberculosis (TB). Infection with HIV is the strongest known risk factor for disease progression to TB. In the absence of HIV infection, disease develops in 5% to 15% of infected persons. Unfortunately, the process of progression to disease is poorly understood. We hypothesize that, in addition to HIV, another sexually transmitted infection (STI) also increases such disease progression. Identification of this STI might suggest new approaches to disease control.Several associations between the risk for TB and lifestyle factors have been identified. [...]<br/
Tuberculosis and sexually transmitted infections
To the Editor: Mycobacterium tuberculosis infection is a necessary, but not sufficient, cause of tuberculosis (TB). Infection with HIV is the strongest known risk factor for disease progression to TB. In the absence of HIV infection, disease develops in 5% to 15% of infected persons. Unfortunately, the process of progression to disease is poorly understood. We hypothesize that, in addition to HIV, another sexually transmitted infection (STI) also increases such disease progression. Identification of this STI might suggest new approaches to disease control.Several associations between the risk for TB and lifestyle factors have been identified. [...]<br/
Spin-orbit coupling in a Quantum Dot at high magnetic field
We describe the simultaneous effects of the spin-orbit (SO) perturbation and
a magnetic field on a disk shaped quantum dot (QD). {As it is known the}
combination of electrostatic forces among the electrons confined in the QD
and the Pauli principle can induce a spin polarization when (applied in the
direction orthogonal to the QD) is above a threshold value. In the presence of
an electric field parallel to , coupled to the spin by a Rashba term,
we demonstrate that a symmetry breaking takes place: we can observe it by
analyzing the splitting of the levels belonging to an unperturbed multiplet. We
also discuss the competitive effects of the magnetic field, the SO perturbation
and the electron electron interaction, in order to define the hierarchy of the
states belonging to a multiplet. We demonstrate how this hierarchy depends on
the QD's size. We show the spin texture due to the combined effects of the
Rashba effect and the interaction responsible for the polarization.Comment: 8 pages, 3 figures, PACS: 73.21.La,71.15.Mb,75.75.+
Quantitative Genetic Mapping and Genome Assembly in the Lesser Wax Moth Achroia grisella
This work is licensed under a Creative Commons Attribution 4.0 International License.Specific characteristics of the male Achroia grisella acoustic mating signal determine a male’s attractiveness toward females. These features are genetically variable in populations, and mapping experiments have been used to identify loci contributing to song variation, and understand the evolutionary forces acting on this important sexual trait. Here we built on this foundation and carried out QTL (Quantitative Trait Locus) mapping using >1,000 recombinant individuals, genotyping this large cohort at thousands of sequence-based markers covering the entire collection of 30 A. grisella chromosomes. This dense marker set, coupled with our development of an annotated, draft genome of A. grisella, allowed us to link >3,000 genome scaffolds, >10,000 predicted genes, and close to 275Mb of genome sequence to chromosomes. Our QTL mapping confirmed a fraction of the QTL identified in a previous study, and additionally revealed novel loci. Collectively, QTL explained only small fractions of the phenotypic variance, suggesting many more causative factors remain below the detection threshold of our study. A surprising, and ultimately challenging feature of our study was the low level of intrachromosomal recombination present in our mapping population. This led to difficulty ordering markers along linkage groups, necessitating a chromosome-by-chromosome mapping approach, rather than true interval mapping, and precluded confident ordering/orienting of scaffolds along each chromosome. Nonetheless, our study increased the genomic resources available for the A. grisella system. Enabled by ever more powerful technologies, future investigators will be able to leverage our data to provide more detailed genetic dissection of male song variation in A. grisella.NSF IOB-0516634NIGMS award P20GM103638NIGMS award P20GM103418NIH R01 GM085260NIH R01 OD01097
The Effect of Diet and Exercise Interventions on Body Composition in Liver Cirrhosis: A Systematic Review
Alterations in body composition, in particular sarcopenia and sarcopenic obesity, are complications of liver cirrhosis associated with adverse outcomes. This systematic review aimed to evaluate the effect of diet and/or exercise interventions on body composition (muscle or fat) in adults with cirrhosis. Five databases were searched from inception to November 2021. Controlled trials of diet and/or exercise reporting at least one body composition measure were included. Single-arm interventions were included if guideline-recommended measures were used (computed tomography/magnetic resonance imaging, dual-energy X-ray absorptiometry, bioelectrical impedance analysis, or ultrasound). A total of 22 controlled trials and 5 single-arm interventions were included. Study quality varied (moderate to high risk of bias), mainly due to lack of blinding. Generally, sample sizes were small (n = 6–120). Only one study targeted weight loss in an overweight population. When guideline-recommended measures of body composition were used, the largest improvements occurred with combined diet and exercise interventions. These mostly employed high protein diets with aerobic and or resistance exercises for at least 8 weeks. Benefits were also observed with supplementary branched-chain amino acids. While body composition in cirrhosis may improve with diet and exercise prescription, suitably powered RCTs of combined interventions, targeting overweight/obese populations, and using guideline-recommended body composition measures are needed to clarify if sarcopenia/sarcopenic obesity is modifiable in patients with cirrhosis
Gardnerella subgroup dominant microbiomes are associated with divergent cervicovaginal immune responses in a longitudinal cohort of Kenyan women
Most cervicovaginal microbiome-immunology studies to date have relied on 16S rDNA microbial profiling which does not resolve the molecular subgroups of Gardnerella, believed to be central to the pathogenesis of bacterial vaginosis (BV) and subsequent risk of HIV acquisition. Here we used the cpn60 universal target which in addition to other microbial taxa, resolves four Gardnerella subgroups, for cervicovaginal microbial profiling in a longitudinal cohort of Kenyan women to examine associations with cellular and soluble markers of inflammation and HIV susceptibility. Participants (N = 41) were sampled, contributing 362 samples for microbiome analysis. All non-Lactobacillus dominant microbial communities were associated with high pro-inflammatory cytokine levels. Divergent associations were observed among different Gardnerella subgroup dominated communities with respect to the chemokine IP-10. Specifically, Gardnerella subgroup A dominant and polymicrobial communities were associated with reduced concentrations of IP-10 in adjusted linear mixed models (p<0.0001), compared to microbial communities dominated by Lactobacillus (non-iners) species. However, these associations did not translate to significant differences in the proportion or absolute number of CCR5, HLA-DR and CD38 expressed on cervical CD4+ T- cells. These findings suggest that some associations between Gardnerella subgroup dominant microbiomes and mucosal immunity differ and are relevant for the study of BV-pathogenesis and understanding the mechanisms of BV-associated HIV risk
Mutation detection in cholestatic patients using microarray resequencing of ATP8B1 and ABCB11
© 2013 McKay KE et al. Background: Neonatal cholestasis is a common presentation of childhood liver diseases and can be a feature of various conditions including disorders of bile acid biogenesis and transport, various inborn errors of metabolism and perinatal infections. Some inherited metabolic diseases can be easily screened using biochemical assays, however many can only be accurately diagnosed by DNA sequencing. Fluorescent capillary Sanger sequencing (FS) is the gold standard method used by clinical laboratories for genetic diagnosis of many inherited conditions; however, it does have limitations. Recently microarray resequencing (MR) has been introduced into research and clinical practice as an alternative method for genetic diagnosis of heterogeneous conditions. In this report we compared the accuracy of mutation detection for MR with FS in a group of patients with 'low-normal' gamma glutamyl transpeptidase (gGT) cholestasis without known molecular diagnoses. Methods: 29 patient DNA samples were tested for mutations in the ATP8B1 and ABCB11 genes using both FS and MR. Other known causes of "low gGT cholestasis such as ARC syndrome and bile acid biosynthesis disorders were excluded. Results: Mutations were identified in 13/29 samples. In 3/29 samples FS and MR gave discordant results: MR had a false positive rate of 3.4% and a false negative rate of 7%. Conclusions: The major advantage of MR over FS is that multiple genes can be screened in one experiment, allowing rapid and cost-effective diagnoses. However, we have demonstrated that MR technology is limited in sensitivity. We therefore recommend that MR be used as an initial evaluation, with FS deployed when genetic and clinical or histopathological findings are discordant
Clinical and Mucosal Immune Correlates of HIV-1 Semen Levels in Antiretroviral-Naive Men.
Background.
This study was done to characterize parameters associated with semen human immunodeficiency virus (HIV)-1 ribonucleic acid (RNA) viral load (VL) variability in HIV-infected, therapy-naive men. Methods.
Paired blood and semen samples were collected from 30 HIV-infected, therapy-naive men who have sex with men, and 13 participants were observed longitudinally for up to 1 year. Human immunodeficiency virus RNA, bacterial load by 16S RNA, herpesvirus (Epstein-Barr virus and cytomegalovirus [CMV]) shedding, and semen cytokines/chemokines were quantified, and semen T-cell subsets were assessed by multiparameter flow cytometry. Results.
Semen HIV RNA was detected at 93% of visits, with \u3e50% of men shedding high levels of virus (defined as \u3e5000 copies/mL). In the baseline cross-sectional analysis, an increased semen HIV VL correlated with local CMV reactivation, the semen bacterial load, and semen inflammatory cytokines, particularly interleukin (IL)-8. T cells in semen were more activated than blood, and there was an increased frequency of Th17 cells and γδ-T-cells. Subsequent prospective analysis demonstrated striking interindividual variability in HIV and CMV shedding patterns, and only semen IL-8 levels and the blood VL were independently associated with semen HIV levels. Conclusions.
Several clinical and immune parameters were associated with increased HIV semen levels in antiretroviral therapy-naive men, with induction of local proinflammatory cytokines potentially acting as a common pathway
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