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Strong Propensity (strong + propensity)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Differential regulation of SOCS-1 signalling in B and T lymphocytes by hepatitis C virus core protein

IMMUNOLOGY, Issue 2 2008
Zhi Qiang Yao
Summary Hepatitis C virus (HCV) infection is characterized by a strong propensity toward chronicity, autoimmune phenomena and lymphomagenesis, supporting a role for lymphocyte dysregulation during persistent viral infection. We have shown that HCV core protein inhibits T-cell functions through interaction with a complement receptor, gC1qR. Here, we further report that B cells also express gC1qR that can be bound by HCV core protein. Importantly, using flow cytometry, we demonstrated differential regulation of B and T lymphocytes by the HCV core,gC1qR interaction, with down-regulation of CD69 activation in T cells but up-regulation of CD69 activation and cell proliferation in B cells. HCV core treatment led to decreased interferon-, production in CD8+ T cells but to increased immunoglobulin M and immunoglobulin G production as well as cell surface expression of costimulatory and chemokine receptors, including CD86 (B7-2), CD154 (CD40L) and CD195 (CCR5), in CD20+ B cells. Finally, we showed down-regulation of suppressor of cytokine signalling-1 (SOCS-1) using real-time reverse transcription,polymerase chain reaction, accompanied by up-regulation of signal transducer and activator of transcription-1 (STAT1) phosphorylation in B cells in response to HCV core protein, with the opposite pattern observed in HCV core-treated T cells. This study demonstrates differential regulation of B and T lymphocytes by HCV core and supports a mechanism by which lymphocyte dysregulation occurs in the course of persistent HCV infection. [source]

On the determination of molecular weight distributions of asphaltenes and their aggregates in laser desorption ionization experiments

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2006
Ana R. Hortal
Abstract Molecular weight distributions (MWD) of asphaltenes and their aggregates have been investigated in laser desorption ionization (LDI) mass spectrometric experiments. A systematic investigation of the dependence of the measured MWD on the asphaltene sample density and on the laser pulse energy allows the assignment of most probable molecular weights within 300,500 amu and average molecular weights of 800,1000 amu for the monomeric asphaltenes, as well as for the estimation of the contribution from asphaltene clusters in typical LDI measurements. The results serve to reconcile the existing controversy between earlier mass spectrometric characterizations of asphaltenes based on laser desorption techniques by different groups. Furthermore, the MWD measurements performed on particularly dense samples yield an additional differentiated broad band peaking around 9000,10 000 amu and extending over 20 000 amu, not observed previously in LDI experiments, thereby revealing a strong propensity of the asphaltenes to form clusters with specific aggregation numbers, which is in qualitative agreement with previous theoretical predictions and with the interpretation of measurements performed with other techniques. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Can Public Housing Authorities Attract and Hold Upwardly Mobile Households?: A Report from Cincinnati

JOURNAL OF URBAN AFFAIRS, Issue 3-4 2001
David P. Varady
Logistic regression analysis is applied to a pooled, cross sectional data set containing results from approximately 1,300 interviews with Cincinnati Metropolitan Housing Authority (CMHA) residents, carried out between 1995 and 1998 to determine overall levels of residential attachment, and to test whether socially mobile householders had especially weak attachments to their locations. The results highlighted a strong propensity to move among CMHA residents generally. Although most residents stated that they were satisfied with their home, nearly three-fifths said that they expected to move within five years. Multivariate results suggested that socially mobile residents (college educated householders, workers, moderate-income households) were using the CMHA stock as a stepping-stone to better rental housing or homeownership. Public housing officials need to decide whether to make a special effort to hold these upwardly mobile households. A more realistic goal would be to minimize residential turnover caused by environmental problems (e.g., crime), regardless of income level. Policies to achieve this goal are discussed. [source]

Specific central nervous system recruitment of HLA-G+ regulatory T cells in multiple sclerosis,

ANNALS OF NEUROLOGY, Issue 2 2009
Yu-Hwa Huang MSci
Objective We have recently described a novel population of natural regulatory T cells (Treg) that are characterized by the expression of HLA-G and may be found at sites of tissue inflammation (HLA-Gpos Treg). Here we studied the role of these cells in multiple sclerosis (MS), a prototypic autoimmune inflammatory disorder of the central nervous system (CNS). Methods Sixty-four patients with different types of MS, 9 patients with other neurological diseases, and 20 healthy donors were included in this study. Inflamed brain lesions from 5 additional untreated MS patients were examined. HLA-Gpos Treg were analyzed in the cerebrospinal fluid (CSF) by flow cytometry and in inflammatory demyelinating lesions of MS brain specimens by immunohistochemistry. Functional capacity was accessed and transmigration was determined using an in vitro model of the human blood-brain barrier (BBB). Results HLA-Gpos Treg were found enriched in the inflamed CSF of MS patients and in inflammatory demyelinating lesions of MS brain specimens. HLA-Gpos Treg showed a strong propensity to transmigrate across BBB, which was vigorously driven by inflammatory chemokines, and associated with a gain of suppressive capacity upon transmigration. CSF-derived HLA-Gpos Treg of MS patients represented a population of activated central memory activated T cells with an upregulated expression of inflammatory chemokine receptors and exhibiting full suppressive capacity. Unlike natural FoxP3-expressing Treg, HLA-Gpos Treg derived from peripheral blood were functionally unimpaired in MS. Interpretation In MS, HLA-Gpos Treg may serve to control potentially destructive immune responses directly at the sites of CNS inflammation and to counterbalance inflammation once specifically recruited to the CNS. Ann Neurol 2009 [source]