Search results for "rase"
showing 10 items of 4343 documents
Is activated hemocyanin instead of phenoloxidase involved in immune response in woodlice?
2008
In the Common woodlouse Porcellio scaber (Crustacea: Isopoda: Oniscidea), experimental immune challenge did not induce the expression of pro-phenoloxidase that, in most other invertebrates studied thus far, can be activated into phenoloxidase via an activation cascade upon immune challenge. Instead, Porcellio hemocyanin proved to exhibit catecholoxidase activity upon activation. However, none of the activating factors known from other invertebrates other than SDS-treatment resulted in activation of hemocyanin into a functional phenoloxidase in vitro. The distinct characteristics of isopod hemocyanin are reflected by the quaternary structure of the hemocyanin dodecamers that differs from tha…
A comparative investigation of DNA adducts, DNA strand breaks and gene mutations induced by benzo[a]pyrene and (+/-)-anti-benzo[a]pyrene-7,8-diol 9,1…
1997
Abstract Genotoxic effects of benzo[ a ]pyrene (BP) and its reactive metabolites (±)- anti -benzo[ a ]pyrene-7,8-diol 9,10-oxide ((±)- anti -BPDE) were comparatively investigated in vitro with the permanent human fibroblast cell line MRC5CV1. Induced DNA adducts were measured by 32 P-postlabeling, DNA strand breakage was determined by the comet assay and the HPRT gene mutation test was used to detect cytotoxicity and mutagenicity. Treatment of MRC5CV1 cells with S9 mix-activated BP or with (±)- anti -BPDE resulted in a concentration-dependent increase in DNA adducts and strand breaks. Genotoxic effects of BP and (±)- anti- BPDE were detected by 32 P-postlabeling and the comet assay with sim…
Genetic basis of human complement C4A deficiency. Detection of a point mutation leading to nonexpression.
1993
Abstract The fourth component of the human complement system (C4) is coded for by two genes, C4A and C4B, located within the MHC. Null alleles of C4 (C4Q0) are defined by the absence of C4 protein in plasma. These null alleles are due either to large gene deletions or to nonexpression of the respective genes. In a previous study, evidence was obtained for nonexpressed defective genes at the C4A locus, and for gene conversion at the C4B locus. To further characterize the molecular basis of these non-expressed C4A genes, we selected nine pairs of PCR primers from flanking genomic intron sequences to amplify all 41 exons from individuals with a defective C4A gene. The amplified products were s…
Gene within gene configuration and expression of the Drosophila melanogaster genes lethal(2) neighbour of tid [l(2)not] and lethal(2) relative of tid…
1997
In this paper, we describe the structure and temporal expression pattern of the Drosophila melanogaster genes l(2)not and l(2)rot located at locus 59F5 vis a vis the tumor suppressor gene l(2)tid described previously and exhibiting a gene within gene configuration. The l(2)not protein coding region, 1530 nt, is divided into two exons by an intron, 2645 nt, harboring the genes l(2)rot, co-transcribed from the same DNA strand, and l(2)tid, co-transcribed from the opposite DNA strand, located vis a vis. To determine proteins encoded by the genes described in this study polyclonal rabbit antibodies (Ab), anti-Not and anti-Rot, were generated. Immunostaining of developmental Western blots with t…
Phosphodiesterase inhibitor pentoxifylline, a selective suppressor of T helper type 1- but not type 2-associated lymphokine production, prevents indu…
1993
The phosphodiesterase inhibitor pentoxifylline (POX), which is known to have pharmacological effects in animal models of multiorgan failure and endotoxin-mediated shock, was tested for its immunosuppressive potential on T lymphocyte activation in vitro and in vivo. POX was found to have a profound inhibitory effect on both mitogen- and antigen-induced proliferation of CD4+ T cells in vitro. This inhibitory activity of the drug could be reproduced by treating T lymphocytes with cAMP analogues during stimulation. Responses of repeatedly in vitro stimulated cells were much more strongly inhibited by the drug and by cAMP analogues than responses of fresh resting lymphocytes. Furthermore, POX co…
T helper 17 lineage differentiation is programmed by orphan nuclear receptors ROR alpha and ROR gamma.
2007
T cell functional differentiation is mediated by lineage-specific transcription factors. T helper 17 (Th17) has been recently identified as a distinct Th lineage mediating tissue inflammation. Retinoic acid receptor-related orphan receptor gamma (ROR gamma) was shown to regulate Th17 differentiation; ROR gamma deficiency, however, did not completely abolish Th17 cytokine expression. Here, we report Th17 cells highly expressed another related nuclear receptor, ROR alpha, induced by transforming growth factor-beta and interleukin-6 (IL-6), which is dependent on signal transducer and activator of transcription 3. Overexpression of ROR alpha promoted Th17 differentiation, possibly through the c…
The protein tyrosine kinase Tec regulates a CD44highCD62L- Th17 subset.
2010
Abstract The generation of Th17 cells has to be tightly controlled during an immune response. In this study, we report an increase in a CD44highCD62L− Th17 subset in mice deficient for the protein tyrosine kinase Tec. CD44highCD62L− Tec−/− CD4+ T cells produced enhanced IL-17 upon activation, showed increased expression levels of IL-23R and RORγt, and IL-23–mediated expansion of Tec−/− CD4+ T cells led to an increased production of IL-17. Tec−/− mice immunized with heat-killed Streptococcus pneumoniae displayed increased IL-17 expression levels in the lung postinfection with S. pneumoniae, and this correlated with enhanced pneumococcal clearance and reduced lung inflammation compared with T…
Neuromuscular junction disassembly and muscle fatigue in mice lacking neurotrophin-4
2001
Neurotrophin-4 (NT-4) is produced by slow muscle fibers in an activity-dependent manner and promotes growth and remodeling of adult motorneuron innervation. However, both muscle fibers and motor neurons express NT-4 receptors, suggesting bidirectional NT-4 signaling at the neuromuscular junction. Mice lacking NT-4 displayed enlarged and fragmented neuromuscular junctions with disassembled postsynaptic acetylcholine receptor (AChR) clusters, reduced AChR binding, and acetylcholinesterase activity. Electromyographic responses, posttetanic potentiation, and action potential amplitude were also significantly reduced in muscle fibers from NT-4 knock-out mice. Slow-twitch soleus muscles from thes…
Dopamine agonist cabergoline reduces hemoconcentration and ascites in hyperstimulated women undergoing assisted reproduction.
2007
Abstract Context: Ovarian hyperstimulation syndrome (OHSS) results from increased vascular permeability (VP) caused by ovarian hypersecretion of vascular endothelial growth factor (VEGF), which activates its receptor-2. In animals, the dopamine receptor 2 agonist cabergoline (Cb2) inactivates VEGF receptor-2 and prevents increased VP. Objective: Our objective was to test whether Cb2 reduces VP and prevents OHSS in humans. Design: We conducted a prospective, randomized, double-blind study on oocyte donors at risk of developing OHSS (>20 follicles, >12 mm developed, and >20 oocytes retrieved). Interventions: Cb2 0.5 mg/d (n = 37) or a placebo (n = 32) was administered fro…
A combined approach for gene discovery identifies insulin-like growth factor-binding protein-related protein 1 as a new gene implicated in human endo…
2003
In the past, human endometrial receptivity has been investigated by chasing specific molecules throughout the menstrual cycle. Now the genomic approach allows us to investigate the hierarchical contribution of a high number of genes to a specific function. In this study, we analyzed differentially the gene expression pattern of 375 human cytokines, chemokines, and related factors, plus that of their receptors, in endometrial receptivity. To do this, we used a combined approach of human endometrium and cell lines. We have compared the gene expression pattern in receptive vs. prereceptive human endometria and contrasted the results with gene expression in the highly adhesive cell line (to JAR…