Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.3.23 (GAS)
 957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A number of studies on throat carriage of beta hemolytic streptococci (BHS) carried out during the years 1972-90 in urban and rural school children from low socioeconomic groups in the age group of 5-15 years in and around Delhi showed an overall carriage rate of BHS varying from 12.2%-64.3% depending upon the season and number of swabs taken. Group A was found to be the most predominant serological group (31.1%-62.6%). The T-typability was found to be 98.2%. The most prevalent T-patterns observed during 1972-78 study were 3/13/B3264 followed by 5/11/12/27/44. A significant difference was observed in the prevalence of T-patterns during the study of 2,034 children from 1979-83 and 3,094 children from 1984-90. When the most prevalent T-patterns were found to be 5/11/12/27/44 followed by 3/13/B3264. The study of the school children from 1972-90 showed the isolation of BHS as well as significant predominance of GAS (p < 0.001) in winter months than summer months. There was no difference in the distribution of carriage of BHS and GAS amongst rural or urban school children. Since RF/RHD are illnesses which were often encountered in school children among socially and economically disadvantaged populations stronger support for streptococcal surveillance programs should be encouraged.
Southeast Asian J Trop Med Public Health 1992 Dec
PMID:Streptococcal throat carriage in school children with special reference to seasonal incidence. 129 77

Of 61 schizophrenic outpatients in remission, 33 who had relapses within the past 20 months were retrospectively examined for prodromal symptoms of relapse. Four weeks prior to the relapse, 63.6% manifested 4 prodromal symptoms, which were somatic concern, feeling of tiredness, anxiety and depressive mood. Contrarily, with the GAS evaluation, no significant deterioration was recognized until one week before the relapse. Subsequently, a prospective observation of symptoms in 43 patients was conducted for 7 months to determine whether therapeutic intervention at the time of the manifestation of prodromal symptoms could be effective in the prevention of relapses and the improvement of outcome of relapses, and to consider the therapeutic use of this method.
Jpn J Psychiatry Neurol 1993 Dec
PMID:Prodromal symptoms of relapse in schizophrenic outpatients: retrospective and prospective study. 791 Nov 65

We have examined the hypothesis that a variable number of tandem repeats in the third cytoplasmic loop of the dopamine D4 receptor influences clinical response to clozapine using a sample of 189 schizophrenic patients. Alleles of the 48-bp repeat, which range from two to ten copies in the normal human population, were analysed by the polymerase chain reaction using genomic DNA as template. Association between these alleles and response to clozapine was tested using the difference in pre- and post-treatment GAS scores as a measure of response. We found no statistically significant variation between genotypic groups and response by analysis of variance. We conclude that the variation of the number of 48-bp repeats alone does not determine response to clozapine. Larger studies are underway to determine if there is a more subtle relationship with sequence variation within the repeats or at other polymorphic sites within the gene that may provide evidence for a component of clozapine's action being at D4 receptors.
Am J Med Genet 1995 Dec 18
PMID:Analysis of clozapine response and polymorphisms of the dopamine D4 receptor gene (DRD4) in schizophrenic patients. 882 92

We have evaluated 23 different statistics, from a total of 10 popular software packages for model-free linkage analysis of nuclear-family data, by applying them to single-marker data simulated under several two-locus disease models. The statistics that we examined fall into two broad categories: (1) those that test directly for increased identity-by-state or identity-by-descent sharing (by use of the programs APM, Genetic Analysis System [GAS] SIBSTATE and SIBDES, SAGE SIBPAL, ERPA, SimIBD, and Genehunter NPL) and (2) those that are based on likelihood-ratio tests and that report LOD scores (by use of the programs Splink, SIBPAIR, Mapmaker/Sibs, ASPEX, and GAS SIBMLS). For each of eight two-locus disease models, we analyzed six data sets; the first three data sets consisted of two-child families with both sibs affected and zero, one, or both parents typed, whereas the other three data sets consisted of four-child families with at least two affected sibs and zero, one, or both parents typed. We report false-positive rates, overall rank by power, and the power for each statistic. We give rough recommendations regarding which programs provide the most powerful tests for linkage, as well as the programs to be avoided under certain conditions. For the likelihood-ratio-based statistics, we examined the effects of various treatments of sibships with multiple affected individuals. Finally, we explored the use of some simple two-of-three composite statistics and found that such tests are of only marginal benefit over the most powerful single statistic.
Am J Hum Genet 1997 Dec
PMID:Comparison of nonparametric statistics for detection of linkage in nuclear families: single-marker evaluation. 939 93

STAT6 mediates interleukin-4 (IL-4)-dependent positive and negative regulation of inflammatory gene expression. In the present report we examined the molecular mechanisms involved in IL-4-induced repression of reporter gene transcription driven by STAT1 and/or NF-kappaB. Transient expression of STAT6 in a STAT6-deficient cell line (HEK 293) conferred sensitivity to IL-4 for STAT6-dependent transcription and for repression of interferon-gamma (IFNgamma)/STAT1- and/or tumor necrosis factor-alpha (TNFalpha)/NF-kappaB-driven reporter gene expression. In cells transfected with a deletion mutant of STAT6 lacking its transactivating domain, IL-4 could not mediate either positive or negative control of reporter gene expression. Overexpression of CREB-binding protein dramatically enhanced IL-4/STAT6-stimulated transcription and overcame IL-4-mediated repression of TNFalpha/NF-kappaB-dependent but not IFNgamma/STAT1-dependent transcription. A single amino acid change in the DNA-binding domain of STAT6 (H415A) selectively reduced the affinity of STAT6 for IL-4-responsive STAT sequence motifs (N4) without affecting the affinity for IFNgamma-responsive (GAS) sequences (N3) and, accordingly, eliminated transcription from an IL-4-responsive promoter. Interestingly, this mutation eliminated IL-4-mediated suppression of reporter gene transcription stimulated by TNFalpha/NF-kappaB but retained nearly full capacity to suppress IFNgamma/STAT1-stimulated transcription. Taken together these results demonstrate that STAT6 mediates suppression of STAT1 and NF-kappaB-dependent transcription by distinct mechanisms. Both processes are dependent upon the STAT6 transactivation domain and may involve sequestration of necessary but different transcriptional coactivator proteins. These two suppressive mechanisms are controlled differentially by the nature of the STAT6 DNA-binding site (i.e. N3 versus N4).
J Biol Chem 2000 Dec 01
PMID:Interleukin-4/STAT6 represses STAT1 and NF-kappa B-dependent transcription through distinct mechanisms. 1098 6

Streptococcus pyogenes (group A streptococcus [GAS]), a multiple-amino-acid-auxotrophic human pathogen, may face starvation for essential amino acids during various stages of the infection process. Since the response of GAS to such conditions is likely to influence pathogenetic processes, we set out to identify by transcriptional analyses genes and operons that are responsive to amino acid starvation and examined whether functionally meaningful response patterns can be ascertained. We discovered that GAS are capable of mounting a relA-independent amino acid starvation response that involves transcriptional modulation of a wide array of housekeeping genes as well as accessory and dedicated virulence genes. Housekeeping genes that were upregulated during starvation of both wild-type and relA mutant strains included the newly identified T-box members of the aminoacyl-tRNA synthetase genes, the genes for components of the tmRNA-mediated peptide tagging and proteolysis system for abnormal proteins (ssrA, smpB, clpP, and clpC), and the operons for the dnaK and groE groups of molecular chaperones. In addition to upregulation of the genes for oligopeptide permease (opp), intracellular peptidase (pepB), and the two-component regulator covRS reported previously (K. Steiner and H. Malke, Mol. Microbiol. 38:1004-1016, 2000), amino acid starvation stimulated the transcription of the growth phase-associated, virulence-regulatory fas operon, the streptolysin S operon (sag), and the gene for autoinducer-2 production protein (luxS). A prominent feature of operons exhibiting internal transcriptional termination (opp, fas, and sag) was starvation-promoted full-length transcription, a mechanism that improves the efficacy of these systems by increasing the level of coordinate transcription of functionally related genes. Based on these results, a regulatory network with feedback mechanisms is proposed that counteracts the stringent response, links the levels of key rate-limiting enzymes to virulence gene expression, and enables the organism in a dynamic way to take advantage of protein-rich environments provided by its human host. As several of the affected target genes are controlled by more than one regulator, fine modulation may result in accordance with the demands imposed by ecologically different colonization sites upon the adaptive capacity of the pathogen.
J Bacteriol 2001 Dec
PMID:relA-Independent amino acid starvation response network of Streptococcus pyogenes. 1171 94

1. In this study we examined the signalling events that regulate lipopolysaccharide (LPS)-stimulated induction of interferon regulatory factor (IRF)-1 in human umbilical vein endothelial cells (HUVECs). 2. LPS stimulated a time- and concentration-dependent increase in IRF-1 protein expression, an effect that was mimicked by the cytokine, tumour necrosis factor (TNF)-alpha. 3. LPS stimulated a rapid increase in nuclear factor kappa B (NFkappaB) DNA-binding activity. Pre-incubation with the NFkappaB pathway inhibitors, N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK) or pyrrolidine dithiocarbamate (PDTC), or infection with adenovirus encoding IkappaBalpha, blocked both IRF-1 induction and NFkappaB DNA-binding activity. 4. LPS and TNFalpha also stimulated a rapid activation of gamma interferon activation site/gamma interferon activation factor (GAS/GAF) DNA-binding in HUVECs. Preincubation with the Janus kinase (JAK)-2 inhibitor, AG490 blocked LPS-stimulated IRF-1 induction but did not affect GAS/GAF DNA-binding. 5. Preincubation with TLCK, PDTC or infection with IkappaBalpha adenovirus abolished LPS-stimulated GAS/GAF DNA-binding. 6. Incubation of nuclear extracts with antibodies to RelA/p50 supershifted GAS/GAF DNA-binding demonstrating the involvement of NFkappaB isoforms in the formation of the GAS/GAF complex. 7. These studies show that NFkappaB plays an important role in the regulation of IRF-1 induction in HUVECs. This is in part due to the interaction of NFkappaB isoforms with the GAS/GAF complex either directly or via an intermediate protein.
Br J Pharmacol 2001 Dec
PMID:Nuclear factor kappa B is involved in lipopolysaccharide-stimulated induction of interferon regulatory factor-1 and GAS/GAF DNA-binding in human umbilical vein endothelial cells. 1173 38

Streptococcus pyogenes (also known as group A Streptococcus, GAS), the agent of streptococcal sore throat and invasive soft-tissue infections, attaches to human pharyngeal or skin epithelial cells through specific recognition of its hyaluronic acid capsular polysaccharide by the hyaluronic-acid-binding protein CD44 (refs 1, 2). Because ligation of CD44 by hyaluronic acid can induce epithelial cell movement on extracellular matrix, we investigated whether molecular mimicry by the GAS hyaluronic acid capsule might induce similar cellular responses. Here we show that CD44-dependent GAS binding to polarized monolayers of human keratinocytes induced marked cytoskeletal rearrangements manifested by membrane ruffling and disruption of intercellular junctions. Transduction of the signal induced by GAS binding to CD44 on the keratinocyte surface involved Rac1 and the cytoskeleton linker protein ezrin, as well as tyrosine phosphorylation of cellular proteins. Studies of bacterial translocation in two models of human skin indicated that cell signalling triggered by interaction of the GAS capsule with CD44 opened intercellular junctions and promoted tissue penetration by GAS through a paracellular route. These results support a model of host cytoskeleton manipulation and tissue invasion by an extracellular bacterial pathogen.
Nature 2001 Dec 06
PMID:Group A Streptococcus tissue invasion by CD44-mediated cell signalling. 1174 May 62

Interferons are essential for establishing cytotoxic T-lymphocyte immunity against viral pathogens through different mechanisms including the modulation of antigen presentation to T-cell subsets. At the present time, interferons have yet to be isolated from teleost fish. We have developed a salmonid model to examine whether MHC gene regulation is modulated during acute viral infection in trout, an event attributable to interferons in mammals. During peak infection with infectious hematopoietic necrosis virus, induction of STAT-1, PSMB9A and ABCB2 mRNA was evident in all tissues within infected fish, as compared with controls. In addition, MHC class Ia and beta(2) microglobulin (beta(2)m) transcript levels were enhanced within the experimental group but surprisingly, splenic and pronephric class IIB mRNA expression was virtually absent. A time-course study looking at 24, 72 and 192 h post-infection was then performed to determine the overall kinetics of this response. STAT-1 and PSMB9A message levels increased early during the immune response and remain at relatively high levels until the final time point. MHC class Ia expression is not consistently upregulated until midway in the response. MHC class IIB transcripts are downregulated by 72 h in the spleen and pronephros and then partially restored by 192 h. Finally, analysis of the putative promoter regions for PSMB9A and ABCB2 identified interferon (IFN) regulatory factory (IRF-1) and INF-gamma (GAS) activation sites that may be involved in the regulation of these genes during viral infection.
Immunogenetics 2002 Dec
PMID:Induction of the rainbow trout MHC class I pathway during acute IHNV infection. 1246 98

Microbes will evolve and the epidemics they cause will continue to occur in the future as they have in the past. Microbes emerge from the evolutionary stream as a result of genetic events and selective pressures that favor new over old. It is nature's way. Microbes and vectors swim in the evolutionary stream, and they swim much faster than humans. Bacteria reproduce every 30 minutes and, for them, a millennium is compressed into a fortnight. They are "fleet afoot," and the pace of research must keep up with them or they will overtake. Microbes were here on Earth 2 billion years before humans arrived, learning every trick of the trade for survival, and they are likely to be here 2 billion years after we depart. Current research on the rise and decline of epidemics is broadly based and includes evolutionary and population genetics of host-microbe relationships. Within this context, the 19th century pandemic of scarlet fever has been described. The possibility is raised that the GAS, which currently cause STSS, possess some of the virulence factors that caused pandemic scarlet fever. Furthermore, the GAS isolated during the recent outbreaks of ARF in certain locales in the United States have the virulence properties of the GAS frequently isolated in the first half of the 20th century. Finally, it is suggested that the strategy to confront emerging infectious diseases should be the study of infectious diseases from all points of view. They remain the greatest threats to our society.
Clin Lab Med 2002 Dec
PMID:Evolving microbes and re-emerging streptococcal disease. 1248 83


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