198 research outputs found
Nutrient Concentrations in Timbalier Bay and the Louisana Oil Patch
Paper by H. P. Burchfield, R. J. Wheeler, and W. Subr
Public Talks and Science Listens: A Community-Based Participatory Approach to Characterizing Environmental Health Risk Perceptions and Assessing Recovery Needs in the Wake of Hurricanes Katrina and Rita
In response to the human health threats stemming from Hurricanes Katrina and Rita, inter-disciplinary working groups representing P30-funded Centers of the National Institute Environmental Health Sciences were created to assess threats posed by mold, harmful alga blooms, chemical toxicants, and various infectious agents at selected sites throughout the hurricane impact zone. Because of proximity to impacted areas, UTMB NIEHS Center in Environmental Toxicology was charged with coordinating direct community outreach efforts, primarily in south Louisiana. In early October 2005, UTMB/NIEHS Center Community Outreach and Education Core, in collaboration with outreach counterparts at The University of Texas MD Anderson Cancer Center @ Smithville TX/Center for Research in Environmental Disease sent two groups into southern Louisiana. One group used Lafourche Parish as a base to deliver humanitarian aid and assess local needs for additional supplies during local recovery/reclamation. A second group, ranging through New Iberia, New Orleans, Chalmette, rural Terrebonne, Lafourche and Jefferson Parishes and Baton Rouge met with community environmental leaders, emergency personnel and local citizens to 1) sample public risk perceptions, 2) evaluate the scope and reach of ongoing risk communication efforts, and 3) determine how the NIEHS could best collaborate with local groups in environmental health research and local capacity building efforts. This scoping survey identified specific information gaps limiting efficacy of risk communication, produced a community “wish list” of potential collaborative research projects. The project provided useful heuristics for disaster response and management planning and a platform for future collaborative efforts in environmental health assessment and risk communication with local advocacy groups in south Terrebonne-Lafourche parishes
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Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases.
Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database ( http://ibdmdb.org ), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases
Cell Spatial Analysis in Crohn's Disease: Unveiling Local Cell Arrangement Pattern with Graph-based Signatures
Crohn's disease (CD) is a chronic and relapsing inflammatory condition that
affects segments of the gastrointestinal tract. CD activity is determined by
histological findings, particularly the density of neutrophils observed on
Hematoxylin and Eosin stains (H&E) imaging. However, understanding the broader
morphometry and local cell arrangement beyond cell counting and tissue
morphology remains challenging. To address this, we characterize six distinct
cell types from H&E images and develop a novel approach for the local spatial
signature of each cell. Specifically, we create a 10-cell neighborhood matrix,
representing neighboring cell arrangements for each individual cell. Utilizing
t-SNE for non-linear spatial projection in scatter-plot and Kernel Density
Estimation contour-plot formats, our study examines patterns of differences in
the cellular environment associated with the odds ratio of spatial patterns
between active CD and control groups. This analysis is based on data collected
at the two research institutes. The findings reveal heterogeneous
nearest-neighbor patterns, signifying distinct tendencies of cell clustering,
with a particular focus on the rectum region. These variations underscore the
impact of data heterogeneity on cell spatial arrangements in CD patients.
Moreover, the spatial distribution disparities between the two research sites
highlight the significance of collaborative efforts among healthcare
organizations. All research analysis pipeline tools are available at
https://github.com/MASILab/cellNN.Comment: Submitted to SPIE Medical Imaging. San Diego, CA. February 202
Razine antinuklearnoga antitijela i reumatoidnoga faktora u radnika izloženih silicijevu dioksidu
A lot of workers in industries such as foundry, stonecutting, and sandblasting are exposed to higher than permissible levels of crystalline silica. Various alterations in humoral immune function have been reported in silicosis patients and workers exposed to silica dust. The aim of this study was to measure antinuclear antibody (ANA) and rheumatoid factor (RF) levels in foundry workers exposed to silica and to compare them with a control group without such exposure. ANA and RF were measured in 78 exposed and 73 non-exposed workers, and standard statistical methods were used to compare them. The two groups did not significantly differ in age and smoking. Mean work duration of the exposed and non-exposed workers was (14.9±4.72) years and (12.41±6.3) years, respectively. Ten exposed workers had silicosis. ANA was negative in all workers in either group. Its mean titer did not differ significantly between the exposed and control workers [(0.39±0.15) IU mL-1 vs. (0.36±0.17) IU mL-1, respectively]. RF was positive in two workers of each group. Other studies have reported an increase in ANA and RF associated with exposure to silica dust and silicosis. In contrast, our study suggests that exposure to silica dust does not increase the level of ANA and RF in exposed workers.Mnogi su radnici izloženi kristalnomu silicijevu dioksidu u razinama iznad dopuštenih. U oboljelih od silikoze i radnika izloženih prašinama koje sadržavaju silicijev dioksid zamijećen je niz oštećenja humoralne obrane. Budući da su radnici u ljevaonicama izloženi visokim razinama kristalnoga silicijeva dioksida, u njih bismo očekivali ovakve humoralne poremećaje. Cilj je ovog ispitivanja bio izmjeriti i usporediti razine antinuklearnih protutijela (ANA) i reumatoidnoga faktora (RF) u krvi radnika u ljevaonici izloženih silicijevu dioksidu i neizložene kontrolne skupine. ANA i RF izmjereni su u 78 izloženih radnika i 73 neizložena radnika te su uspoređeni s pomoću standardnih statističkih metoda. Dvije se skupine nisu bitno razlikovale u broju pušača i u dobi. Prosječna duljina radnog vijeka izloženih radnika bila je (14,9±4,72) godine, a neizloženih (12,41±6,3) godine. Deset izloženih radnika imalo je silikozu. Nalazi ANA bili su negativni u obje skupine radnika. Srednja vrijednost titra ANA iznosila je (0,39±0,15) IU mL-1 u izloženih ispitanika, a (0,36±0,17) IU mL-1 u kontrola, što je statistički zanemariva razlika. Nalaz RF-a bio je pozitivan u dva izložena te dva kontrolna radnika. Naše ispitivanje upućuje na to da prašine silicijeva dioksida ne uzrokuju porast razina ANA i RF-a u izloženih radnika
Identifying high-impact variants and genes in exomes of Ashkenazi Jewish inflammatory bowel disease patients
Inflammatory bowel disease (IBD) is a group of chronic digestive tract inflammatory conditions whose genetic etiology is still poorly understood. The incidence of IBD is particularly high among Ashkenazi Jews. Here, we identify 8 novel and plausible IBD-causing genes from the exomes of 4453 genetically identified Ashkenazi Jewish IBD cases (1734) and controls (2719). Various biological pathway analyses are performed, along with bulk and single-cell RNA sequencing, to demonstrate the likely physiological relatedness of the novel genes to IBD. Importantly, we demonstrate that the rare and high impact genetic architecture of Ashkenazi Jewish adult IBD displays significant overlap with very early onset-IBD genetics. Moreover, by performing biobank phenome-wide analyses, we find that IBD genes have pleiotropic effects that involve other immune responses. Finally, we show that polygenic risk score analyses based on genome-wide high impact variants have high power to predict IBD susceptibility
Combined Simulation and Experimental Study of Large Deformation of Red Blood Cells in Microfluidic Systems
Author manuscript; available in PMC 2012 March 1.We investigate the biophysical characteristics of healthy human red blood cells (RBCs) traversing microfluidic channels with cross-sectional areas as small as 2.7 × 3 μm. We combine single RBC optical tweezers and flow experiments with corresponding simulations based on dissipative particle dynamics (DPD), and upon validation of the DPD model, predictive simulations and companion experiments are performed in order to quantify cell deformation and pressure–velocity relationships for different channel sizes and physiologically relevant temperatures. We discuss conditions associated with the shape transitions of RBCs along with the relative effects of membrane and cytosol viscosity, plasma environments, and geometry on flow through microfluidic systems at physiological temperatures. In particular, we identify a cross-sectional area threshold below which the RBC membrane properties begin to dominate its flow behavior at room temperature; at physiological temperatures this effect is less profound.Singapore-MIT Alliance for Research and TechnologyUnited States. National Institutes of Health (National Heart, Lung, and Blood Institute Award R01HL094270
Multiscale Modeling of Red Blood Cell Mechanics and Blood Flow in Malaria
Red blood cells (RBCs) infected by a Plasmodium parasite in malaria may lose their membrane deformability with a relative membrane stiffening more than ten-fold in comparison with healthy RBCs leading to potential capillary occlusions. Moreover, infected RBCs are able to adhere to other healthy and parasitized cells and to the vascular endothelium resulting in a substantial disruption of normal blood circulation. In the present work, we simulate infected RBCs in malaria using a multiscale RBC model based on the dissipative particle dynamics method, coupling scales at the sub-cellular level with scales at the vessel size. Our objective is to conduct a full validation of the RBC model with a diverse set of experimental data, including temperature dependence, and to identify the limitations of this purely mechanistic model. The simulated elastic deformations of parasitized RBCs match those obtained in optical-tweezers experiments for different stages of intra-erythrocytic parasite development. The rheological properties of RBCs in malaria are compared with those obtained by optical magnetic twisting cytometry and by monitoring membrane fluctuations at room, physiological, and febrile temperatures. We also study the dynamics of infected RBCs in Poiseuille flow in comparison with healthy cells and present validated bulk viscosity predictions of malaria-infected blood for a wide range of parasitemia levels (percentage of infected RBCs with respect to the total number of cells in a unit volume).United States. National Institutes of Health (Grant R01HL094270)National Science Foundation (U.S.). (Grant CBET-0852948)Singapore-MIT Alliance for Research and Technology Cente
Biophysics of Malarial Parasite Exit from Infected Erythrocytes
Upon infection and development within human erythrocytes, P. falciparum induces alterations to the infected RBC morphology and bio-mechanical properties to eventually rupture the host cells through parasitic and host derived proteases of cysteine and serine families. We used previously reported broad-spectrum inhibitors (E64d, EGTA-AM and chymostatin) to inhibit these proteases and impede rupture to analyze mechanical signatures associated with parasite escape. Treatment of late-stage iRBCs with E64d and EGTA-AM prevented rupture, resulted in no major RBC cytoskeletal reconfiguration but altered schizont morphology followed by dramatic re-distribution of three-dimensional refractive index (3D-RI) within the iRBC. These phenotypes demonstrated several-fold increased iRBC membrane flickering. In contrast, chymostatin treatment showed no 3D-RI changes and caused elevated fluctuations solely within the parasitophorous vacuole. We show that E64d and EGTA-AM supported PV breakdown and the resulting elevated fluctuations followed non-Gaussian pattern that resulted from direct merozoite impingement against the iRBC membrane. Optical trapping experiments highlighted reduced deformability of the iRBC membranes upon rupture-arrest, more specifically in the treatments that facilitated PV breakdown. Taken together, our experiments provide novel mechanistic interpretations on the role of parasitophorous vacuole in maintaining the spherical schizont morphology, the impact of PV breakdown on iRBC membrane fluctuations leading to eventual parasite escape and the evolution of membrane stiffness properties of host cells in which merozoites were irreversibly trapped, recourse to protease inhibitors. These findings provide a comprehensive, previously unavailable, body of information on the combined effects of biochemical and biophysical factors on parasite egress from iRBCs.Singapore. Agency for Science, Technology and ResearchSingapore-MIT AllianceGlobal Enterprise for Micro-Mechanics and Molecular MedicineNational University of SingaporeNational Institutes of Health (U.S.) (Grant R01 HL094270-01A1)National Institutes of Health (U.S.) (Grant 1-R01-GM076689-01)National Institutes of Health (U.S.) (P41-RR02594-18-24
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