31 resultados para T helper type 17
em Scielo Saúde Pública - SP
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We determined the serum IgE levels and T-helper (Th)17-related cytokines during distinct hepatitis A virus (HAV)-induced clinical courses in children. A significantly higher concentration of macrophage inflammatory protein 3α, interleukin (IL)-17E and IL-17F in HAV-infected children with intermediate liver injury compared with those with minor liver damage was found. A reduction in the IgE levels in those patients who showed the highest levels of IL-17F in the group of intermediate liver injury was found. The data suggested that the Th17-related profile is associated with the severity of HAV infection and might play a role on the modulation achieved by HAV during allergies.
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It has been reported that production of IL-2 and IFN-
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OBJECTIVE: To assess the feasibility and safety of coronary interventions performed through the radial artery. METHODS: We studied 103 patients with ages from 38 to 86 years (57±8.7), 90 (87%) males, and: radial pulse with a good amplitude, presence of ulnar pulse, a good collateral flow through the palmar arch assessed with the Allen's test. RESULTS: The vascular approach was obtained in 97 (94%) patients, 88 (91%) treated electively and 9 (9%) during acute myocardial infarction, for primary angioplasty; 56 (64%) unstable angina; 22 (25%) stable angina; 10 (11%) were asymptomatic, 6 referred for recanalization of chronic occlusion and 4 silent ischemia in the first week after acute myocardial infarction. We approached 107 arteries: anterior descending artery, 49 (46%); right coronary artery, 27 (25%); circumflex artery, 25 (23%); diagonal artery, 6 (6%); and 2 saphenous vein bypass grafts. We treated 129 lesions: 80 (62%) B2 type; 23 (18%) B1 type; 17 (13%) C type; and 9 (7%). A type. There were 70 stents , and 59 balloon angioplasties performed. Thirty-two (33%) patients used GP IIb/IIIa inhibitors. The mean duration of the elective procedure was 42.3±12.8 min. Success, correct stent deployment and residual lesion <20%, was reached in 100% of the lesions treated with stent implantation; arterial dilation with residual lesion <50% was obtained in 96% of the lesions treated with transluminal coronary angioplasty (TCA). Complications, were: 1 (1.0%) non-Q-wave acute myocardial infarction; 2 (2%) hematomas in the forearm; and 2 losses of radial pulse. CONCLUSION: Radial artery aproach is practical and safe for percutaneous coronary interventions there was a low incidence of complications.
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We showed that a large fraction of lepromatous patients do harbor helper-type circulating T-cells that can be activated in vitro by Mycobacterium leprae. M. leprae and PPD triggered T-cell lines could be then obtained from both tuberculoid and lepromatous patients. The proliferative response of these helper T-cells is predominantly directed against epitopes shared by several species of mycobacteria, in lepromatous patients as well as in tuberculoid patients, but species specific T-cells are also present. When presented in the context of M. leprae, these cross reactive epitopes usually fail to stimulate the T-cell lines of lepromatous patients, because of the contamination of the lines by supressor T-cells actavable by M. leprae. In one lepromatous patient, PPD and M. leprae reactive T-cell lines and clones (of the CD4 phenotype), exhibited a strong cytotoxic activity to autologous target cells coated with antigen: the relevance of this phenomenon to the pathophysiology of lepromatous leprosy remains however unknown.
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This work aimed to study the T helper type 1/2 (Th1/Th2) cytokine profile in a co-infection murine model of Plasmodium chabaudi chabaudi and Leishmania infantum. Expression of interferon-gamma (IFN
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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that involves the inflammation of various organs upon deposition of immune complexes and is characterized by uncontrolled B cell hyperactivity. Despite intensive research on the etiology of the disease, the exact cause of the onset of SLE is unknown. The pathogenesis of the disease has been proposed to be associated with the imbalance of T helper type 1 (Th1) and Th2 cytokine activities. Elevated serum levels of interleukin-6 (IL-6), a Th2 cytokine with various functions in the regulation of human biological systems, are observed in SLE patients. In the present study, 100 Malaysian SLE patients and 100 controls were evaluated in order to determine the association of polymorphisms existing in the promoter region of the IL-6 gene with the onset of SLE. The homozygous G genotype was found to be significant in SLE patients (χ² = 33.754; P = 0.00000000625), whereas the heterozygous G/C genotype was significant in the controls (χ²= 25.087; P = 0.000000548). We suggest that the C allele might have a masking effect on the G allele when both alleles are present in heterozygous individuals. However, we did not observe any significant association of the homozygous C allele with the onset of SLE or with protection from the disease (χ² = 1.684; P = 0.194366).
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The traditional concept that effector T helper (Th) responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17) and the follicular helper T cells (Tfh). These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R), the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases.
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Haemophilus influenzae is one of the most important bacterial agents of otitis and sinusitis. H. influenzae type b (Hib) is one of the main causes of meningitis, pneumonia, and septicemia in nonvaccinated children under 6 years of age. The aims of this study were to determine the prevalence of H. influenzae and Hib oropharyngeal colonization prior to the onset of the Hib vaccination program in Brazil in previously healthy children and to assess the susceptibility profile of this microorganism to a selected group of antimicrobials that are used to treat acute respiratory infections. METHOD: Cultures of Haemophilus influenzae were made from oropharynx swabs from 987 children under 6 years of age who were enrolled in 29 day-care centers in Taubaté (a city of São Paulo state, Brazil) between July and December 1998. RESULTS: The prevalence of H. influenzae carriers was 17.4%, and only 5.5% of the strains were beta-lactamase producers. The prevalence of Hib carriers was high, 7.3% on average (range, 0.0 - 33.3%). CONCLUSIONS: The low prevalence of colonization by penicillin-resistant strains indicates that it is not necessary to substitute ampicilin or amoxicilin to effectively treat otitis and sinusitis caused by H. influenzae in Taubaté.
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Abstract Background: Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. Objective: The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Methods: Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Results: Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. Conclusion: The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.
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The Brazilian variant of human immunodeficiency virus type 1 (HIV-1) subtype B, (serotype B"-GWGR), has a tryptophan replacing the proline in position 328 the HIV-1 envelope. A longer median time period from infection to acquired immunodeficiency syndrome (AIDS) for serotype B (B"-GWGR) infected subjects compared to the B-GPGR US/European strain was reported. In a cohort study, in São Paulo city, 10 B"-GWGR patients had a statistically significant increased avidity of the anti-V3 antibodies, from 79% ± 33% to 85% ± 75%, versus from 48% ± 59% to 32% ± 17% for the 10 B-GPGR subjects (p = 0.02). The T CD4+ cells showed a mean increase of + 0.45 cells/month for the B-GPGR subjects and for B"-GWGR the slope was + 1.24 cells/month (p = 0.06), for 62 and 55 months of follow up, respectively. RNA plasma viral load decreased from 3.98 ± 1.75 to 2.16 ± 1.54 log10 in the B"-GWGR group while B-GPGR patients showed one log10 reduction in viral load from 4.09 ± 0.38 to 3.17 ± 1.47 log10 over time (p = 0.23), with a decreasing slope of 0.0042 ± log10,/month and 0.0080 ± log10/month, for B-GPGR and B"-GWGR patients, respectively (p = 0.53). Neither group presented any AIDS defining events during the study, according to Center for Diseases Control criteria. Although the sample size is small, these results may indicate that differences in the pathogenicity of the 2 HIV-1 B serotypes which co-circulate in Brazil may be correlated to the avidity of anti-V3 antibodies.
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In order to estimate the prevalence of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) co-infection in hard-to-reach intravenous drug users, 199 subjects from high-risk inner-city locales, the so called "shooting galleries", were consented, interviewed, and tested in Miami, FL, US. Positive HIV-1 status was based on repeatedly reactive ELISA and confirmatory Western Blot. Positive HCV status was based on reactive ELISA and confirmatory polymerase chain reaction techniques. Overall, 50 (25%) were not infected with either virus, 61 (31%) were HIV-1/HCV co-infected, 17 (8%) infected by HIV-1 only, and 71 (36%) infected by HCV only. The results of the multivariable analyses showed that more years using heroin was the only significant risk factor for HCV only infection (odds ratio = 1.15; 95% confidence interval = 1.07, 1.24) and for HIV-1/HCV co-infection (odds ratio = 1.17; 95% confidence interval = 1.09, 1.26). This paper demonstrates that HIV-1/HCV co-infection is highly prevalent among so called "shooting galleries".
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This study was carried out to evaluate the molecular pattern of all available Brazilian human T-cell lymphotropic virus type 1 Env (n = 15) and Pol (n = 43) nucleotide sequences via epitope prediction, physico-chemical analysis, and protein potential sites identification, giving support to the Brazilian AIDS vaccine program. In 12 previously described peptides of the Env sequences we found 12 epitopes, while in 4 peptides of the Pol sequences we found 4 epitopes. The total variation on the amino acid composition was 9 and 17% for human leukocyte antigen (HLA) class I and class II Env epitopes, respectively. After analyzing the Pol sequences, results revealed a total amino acid variation of 0.75% for HLA-I and HLA-II epitopes. In 5 of the 12 Env epitopes the physico-chemical analysis demonstrated that the mutations magnified the antigenicity profile. The potential protein domain analysis of Env sequences showed the loss of a CK-2 phosphorylation site caused by D197N mutation in one epitope, and a N-glycosylation site caused by S246Y and V247I mutations in another epitope. Besides, the analysis of selection pressure have found 8 positive selected sites (w = 9.59) using the codon-based substitution models and maximum-likelihood methods. These studies underscore the importance of this Env region for the virus fitness, for the host immune response and, therefore, for the development of vaccine candidates.
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Catalogue of the type-specimens of Bolitophilidae, Diadocidiidae and Ditomyiidae (Diptera, Bibionomorpha) in the Natural History Museum, London. A commented list of the types of three families of Bibionomorpha - Bolitophilidae, Diadocidiidae and Ditomyiidae - housed at the Natural History Museum (London) is provided. This includes four holotypes and one paratype of five species of Bolitophilidae; one paratype and three syntypes of two species of Diadocidiidae; and 17 holotypes, 91 paratypes, four lectotypes, and fourteen paralectotypes of 38 species of Ditomyiidae. Lectotypes are designated for the Neotropical species of the ditomyiids Australosymmerus (Melosymmerus) bisetosus Edwards, 1940 and A. (M.) pediferus Edwards, 1940.
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The immunogenicity of an inactivated, experimental vaccine based on a bovine herpesvirus type 5 strain defective in thymidine kinase and glycoprotein E (BoHV-5 gE/TKΔ) was evaluated in cattle and the results were compared with a vaccine containing the parental BoHV-5 strain (SV507/99). To formulate the vaccines, each virus (wildtype SV507/99 and BoHV-5 gE/TK∆) was multiplied in cell culture and inactivated with binary ethyleneimine (BEI). Each vaccine dose contained approximately of 10(7.5) TCID50 of inactivated virus mixed with an oil-based adjuvant (46:54). Forty calves, 6 to 9-months-old, were allocated into two groups of 20 animals each and vaccinated twice (days 0 and 22pv) by the subcutaneous route with either vaccine. Serum samples collected at day 0 and at different intervals after vaccination were tested for virus neutralizing (VN) antibodies against the parental virus and against heterologous BoHV-5 and BoHV-1 isolates. The VN assays demonstrated seroconversion to the respective homologous viruses in all vaccinated animals after the second vaccine dose (mean titers of 17.5 for the wildtype vaccine; 24.1 for the recombinant virus). All animals remained reagents up to day 116 pv, yet showing a gradual reduction in VN titers. Animals from both vaccine groups reacted in similar VN titers to different BoHV-1 and BoHV-5 isolates, yet the magnitude of serological response of both groups was higher against BoHV-5 field isolates. Calves vaccinated with the recombinant virus did not develop antibodies to gE as verified by negative results in a gE-specific ELISA, what would allow serological differentiation from naturally infected animals. Taken together, these results indicate that inactivated antigens of BoHV-5 gE/TK recombinant virus induced an adequate serological response against BoHV-5 and BoHV-1 and thus can be used as an alternative, differential vaccine candidate.
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Diabetic nephropathy (DN) is characterized structurally by progressive mesangial deposition of extracellular matrix (ECM). Transforming growth factor-ß (TGF-ß) is considered to be one of the major cytokines involved in the regulation of ECM synthesis and degradation. Several studies suggest that an increase in urinary TGF-ß levels may reflect an enhanced production of this polypeptide by the kidney cells. We evaluated TGF-ß in occasional urine samples from 14 normal individuals and 23 patients with type 2 diabetes (13 with persistent proteinuria >500 mg/24 h, DN, 6 with microalbuminuria, DMMA, and 4 with normal urinary albumin excretion, DMN) by enzyme immunoassay. An increase in the rate of urinary TGF-ß excretion (pg/mg UCreat.) was observed in patients with DN (296.07 ± 330.77) (P<0.001) compared to normal individuals (17.04 ± 18.56) (Kruskal-Wallis nonparametric analysis of variance); however, this increase was not observed in patients with DMMA (25.13 ± 11.30) or in DMN (18.16 ± 11.82). There was a positive correlation between the rate of urinary TGF-ß excretion and proteinuria (r = 0.70,