999 resultados para C-12(LAMBDA)
Resumo:
As in many areas of Brazil, the AIDS epidemic in Curitiba is relatively stable, but surveillance is important to support public policy. The molecular characteristics of HIV may be instrumental for monitoring epidemic trends. We evaluated plasma HIV-1 RNA (n = 37) from 38 cases presenting with positive serology, who were among 820 consenting volunteers visiting the downtown counselling and serology testing centre. Seroprevalence was 4.6% (CI 95% 3.2-6.3) and the estimated HIV incidence, as defined by the BED assay, was 2.86 persons/years (CI 95% 1.04-4.68). An additional set of contemporaneous, anonymous samples from a local laboratory was also analysed (n = 20). Regions of the HIV-1 polymerase (n = 57) and envelope (n = 34) were evaluated for subtyping, determination of mosaic structure, primary drug resistance mutations (pDRM), envelope V3 loop motifs and amino acid signatures related to viral tropism. HIV-1 clade B was observed in 53% of cases; HIV-1C in 30% and BC mosaics in 14%, with one F genome and one CF mosaic. Clade C infection was associated with recent infections among males (p < 0.03). Stanford surveillance pDRM was observed in 8.8% of sequences, with 7% showing high level resistance to at least one antiretroviral drug. Tropism for CXCR4 co-receptor was predicted in 18% of envelope sequences, which were exclusively among clade B genomes and cases with serological reactivity to chronic infection.
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This study was performed with the purpose of testing the hypothesis that the high prevalence of hepatitis C among former athletes is associated with their past use of injectable stimulants. The study involved the participation of 208 former professional and amateur soccer and basketball players from the region of Ribeirão Preto, Brazil, who answered a questionnaire regarding their exposure to risk factors, including the use of injectable stimulants in the time they were engaged in sporting activities. ELISA tests were used to detect infection by the hepatitis C virus, and confirmed with PCR and genotyping for the positive cases. It was observed that the former use of injectable stimulants was a practice disseminated among the participants (24.5%), reaching 50.8% in the professionals. The overall prevalence for hepatitis C was 7.2%, with values of 11% among professionals and 5.5% among amateurs. In both categories, the presence of infection was markedly higher among those who admitted past use of injectable stimulants when compared to those who denied such practice (36% and 0.8% among amateurs; 21.9% and 0% among professionals, respectively). Multivariate analysis showed that the use of those substances was the only variable associated with the risk of hepatitis C. This confirms previous observations, performed with reduced sample sizes and without comparison groups, which indicated that the use of injectable vitamins was a risk factor of hepatitis C among former athletes.
Resumo:
CONTEXT: Primary pigmented nodular adrenocortical disease (PPNAD), a rare cause of corticotropin-independent Cushing syndrome, can be part of Carney complex (CNC), an autosomal dominant multiple neoplasia syndrome characterized by spotty skin pigmentation, cardiac myxomas, and endocrine tumors or be isolated (i). Germline PRKAR1A-inactivating mutations have been observed in both CNC and iPPNAD, but with no apparent genotype-phenotype correlation. OBJECTIVE:The objectives of the study were a detailed phenotyping for CNC manifestations in 12 kindreds bearing the same PRKAR1A mutation and a study of the consequences of the mutation and a potential founder effect. DESIGN: The study consisted of descriptive case reports. SETTING: The study was conducted at two referral centers. PATIENTS: The patients described in this study were referred for PRKAR1A gene mutation analysis because of a diagnosis of apparently iPPNAD. RESULTS: We describe a 6-bp polypyrimidine tract deletion [exon 7 IVS del (-7-->-2)] in 12 unrelated kindreds that were referred for Cushing syndrome due to PPNAD. Nine of the patients had no family history; in two, there was a family history of iPPNAD. Only one patient met the criteria for CNC. Relatives carrying the same mutation had no manifestations of CNC or PPNAD, suggesting a low penetrance of this PRKAR1A defect. A founder effect was excluded by extensive genotyping of chromosome 17 markers. CONCLUSIONS: In conclusion, a small intronic deletion of the PRKAR1A gene is a low-penetrance cause of mainly iPPNAD; it is the first PRKAR1A genetic defect to have an association with a specific phenotype.
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The plasticity of mature oligodendrocytes was studied in aggregating brain cell cultures at the period of maximal expression of myelin marker proteins. The protein kinase C (PKC)-activating tumor promoters mezerein and phorbol 12-myristate 13-acetate (PMA), but not the inactive phorbol ester analog 4alpha-PMA, caused a pronounced decrease of myelin basic protein (MBP) content and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity. In contrast, myelin/oligodendrocyte protein (MOG) content was affected relatively little. Northern blot analyses showed a rapid reduction of MBP and PLP gene expression induced by mezerein, and both morphological and biochemical findings indicate a drastic loss of compact myelin. During the acute phase of demyelination, only a relatively small increase in cell death was perceptible by in situ end labeling and in situ nick translation. Basic fibroblast growth factor (bFGF) also reduced the levels of the oligodendroglial differentiation markers and enhanced the demyelinating effects of the tumor promoters. The present results suggest that PKC activation resulted in severe demyelination and partial loss of the oligodendrocyte-differentiated phenotype.
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The host immune response plays an important role in viral clearance in patients who are chronically infected with hepatitis C virus (HCV) and are treated with interferon and ribavirin. Activation of the immune system involves the release of pro and anti-inflammatory molecules that can be measured in plasma samples. The present study aimed to evaluate the association between pretreatment plasma levels of chemokines and soluble tumor necrosis factor receptors (sTNF-R) and the virological response in treated patients with chronic hepatitis C infection. Forty-one chronically-infected HCV patients that were being treated with interferon-α (IFN-α) plus ribavirin were included in the study. Socio-demographic, clinical and laboratory data were collected and pretreatment plasma levels of chemokine CCL2, CCL3, CCL11, CCL24, chemokine CXCL9, CXCL10, sTNF-R1 and sTNF-R2 were measured. The virological response was assessed at treatment week 12, at the end of treatment and 24 weeks after treatment. Pretreatment CXCL10 levels were significantly higher in patients without an early virological response (EVR) or sustained virological response (SVR) compared to responders [512.9 pg/mL vs. 179.1 pg/mL (p = 0.011) and 289.9 pg/mL vs. 142.7 pg/mL (p = 0.045), respectively]. The accuracy of CXCL10 as a predictor of the absence of EVR and SVR was 0.79 [confidence interval (CI) 95%: 0.59-0.99] and 0.69 (CI 95%: 0.51-0.87), respectively. Pretreatment plasma levels of the other soluble inflammatory markers evaluated were not associated with a treatment response. Pretreatment CXCL10 levels were predictive of both EVR and SVR to IFN-α and ribavirin and may be useful in the evaluation of candidates for therapy.
Resumo:
Applications of genetic constructs with multiple promoters, which are fused with reporter genes and simultaneous monitoring of various events in cells, have gained special attention in recent years. Lentiviral vectors, with their distinctive characteristics, have been considered to monitor the developmental changes of cells in vitro. In this study, we constructed a novel lentiviral vector (FUM-M), containing two germ cell-specific promoters (Stra8 and c-kit), fused with ZsGreen and DsRed2 reporter genes, and evaluated its efficiency in different cells following treatments with retinoic acid and DMSO. Several cell lines (P19, GC-1 spg and HEK293T) were transduced with this vector, and functional capabilities of the promoters were verified by flow cytometry and quantitative RT-PCR. Our results indicate that FUM-M shows dynamic behavior in the presence and absence of extrinsic factors. A correlation was also observed between the function of promoters, present in the lentiviral construct and the endogenous level of the Stra8 and c-kit mRNAs in the cells. In conclusion, we recommend this strategy, which needs further optimization of the constructs, as a beneficial and practical way to screen chemical inducers involved in cellular differentiation toward germ-like cells.
Resumo:
We present early estimates of influenza vaccine effectiveness (VE) in the population targeted for vaccination, during 25 December 2011 to 19 February 2012. The adjusted VE was 55% (95% CI: 3 to 79) against any type of influenza virus and 54% (95% CI: 1 to 79) against influenza A(H3N2) virus. This suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.
Resumo:
Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20%. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24%) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.
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The haematological changes and release of soluble mediators, particularly C-reactive protein (CRP) and nitric oxide (NO), during uncomplicated malaria have not been well studied, especially in Brazilian areas in which the disease is endemic. Therefore, the present study examined these factors in acute (day 0) and convalescent phase (day 15) patients infected with Plasmodium falciparum and Plasmodium vivax malaria in the Brazilian Amazon. Haematologic parameters were measured using automated cell counting, CRP levels were measured with ELISA and NO plasma levels were measured by the Griess reaction. Our data indicate that individuals with uncomplicated P. vivax and P. falciparum infection presented similar inflammatory profiles with respect to white blood cells, with high band cell production and a considerable degree of thrombocytopaenia during the acute phase of infection. Higher CRP levels were detected in acute P. vivax infection than in acute P. falciparum infection, while higher NO was detected in patients with acute and convalescent P. falciparum infections. Although changes in these mediators cannot predict malaria infection, the haematological aspects associated with malaria infection, especially the roles of platelets and band cells, need to be investigated further.
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Leprosy spectrum and outcome is associated with the host immune response against Mycobacterium leprae. The role of coinfections in leprosy patients may be related to a depression of cellular immunity or amplification of inflammatory responses. Leprosy remains endemic in several regions where human T cell lymphotrophic virus type 1 (HTLV-1), hepatitis B virus (HBV) or hepatitis C virus (HCV) are also endemic. We have evaluated the evidence for the possible role of these viruses in the clinical manifestations and outcomes of leprosy. HTLV-1, HBV and HCV are associated with leprosy in some regions and institutionalization is an important risk factor for these viral coinfections. Some studies show a higher prevalence of viral coinfection in lepromatous cases. Although HBV and HCV coinfection were associated with reversal reaction in one study, there is a lack of information about the consequences of viral coinfections in leprosy. It is not known whether clinical outcomes associated with leprosy, such as development of reactions or relapses could be attributed to a specific viral coinfection. Furthermore, whether the leprosy subtype may influence the progression of the viral coinfection is unknown. All of these important and intriguing questions await prospective studies to definitively establish the actual relationship between these entities.
Resumo:
A single-nucleotide polymorphism (SNP) upstream of interleukin (IL)28B was recently identified as an important predictor of the outcome of chronic hepatitis C patients treated with pegylated interferon plus ribavirin (PEG-IFN/RBV). The aim of this study was to investigate the association between the IL28B gene polymorphism (rs12979860) and virological response in chronic hepatitis C patients. Brazilian patients (n = 263) who were infected with hepatitis C virus (HCV) genotype 1 and were receiving PEG-IFN/RBV were genotyped. Early virological response (EVR) (12 weeks), end-of-treatment response (EOTR) (48 weeks), sustained virological response (SVR) (72 weeks) and relapse were evaluated using conventional and quantitative polymerase chain reaction (PCR) assays. The frequency of the C allele in the population was 39%. Overall, 43% of patients experienced SVR. The IL28B CC genotype was significantly associated with higher treatment response rates and a lower relapse rate compared to the other genotypes [84% vs. 58% EVR, 92% vs. 63% EOTR, 76% vs. 38% SVR and 17% vs. 40% relapse rate in CC vs. other genotypes (CT and TT), respectively]. Thus, the IL28B genotype appears to be a strong predictor of SVR following PEG-IFN/RBV therapy in treatment-naïve Brazilian patients infected with HCV genotype 1. This study, together with similar research examining other SNPs, should help to define adequate protocols for the treatment of patients infected with HCV genotype 1, especially those with a poor prognosis.
Resumo:
Non-structural protein 2 (NS2) plays an important role in hepatitis C virus (HCV) assembly, but neither the exact contribution of this protein to the assembly process nor its complete structure are known. In this study we used a combination of genetic, biochemical and structural methods to decipher the role of NS2 in infectious virus particle formation. A large panel of NS2 mutations targeting the N-terminal membrane binding region was generated. They were selected based on a membrane topology model that we established by determining the NMR structures of N-terminal NS2 transmembrane segments. Mutants affected in virion assembly, but not RNA replication, were selected for pseudoreversion in cell culture. Rescue mutations restoring virus assembly to various degrees emerged in E2, p7, NS3 and NS2 itself arguing for an interaction between these proteins. To confirm this assumption we developed a fully functional JFH1 genome expressing an N-terminally tagged NS2 demonstrating efficient pull-down of NS2 with p7, E2 and NS3 and, to a lower extent, NS5A. Several of the mutations blocking virus assembly disrupted some of these interactions that were restored to various degrees by those pseudoreversions that also restored assembly. Immunofluorescence analyses revealed a time-dependent NS2 colocalization with E2 at sites close to lipid droplets (LDs) together with NS3 and NS5A. Importantly, NS2 of a mutant defective in assembly abrogates NS2 colocalization around LDs with E2 and NS3, which is restored by a pseudoreversion in p7, whereas NS5A is recruited to LDs in an NS2-independent manner. In conclusion, our results suggest that NS2 orchestrates HCV particle formation by participation in multiple protein-protein interactions required for their recruitment to assembly sites in close proximity of LDs.
Resumo:
BACKGROUND: In Switzerland, intravenous drug use (IDU) accounts for 80% of newly acquired hepatitis C virus (HCV) infections. Early HCV treatment has the potential to interrupt the transmission chain and reduce morbidity/mortality due to decompensated liver cirrhosis and hepatocellular carcinoma. Nevertheless, patients in drug substitution programs are often insufficiently screened and treated. OBJECTIVE/METHODS: With the aim to improve HCV management in IDUs, we conducted a cross sectional chart review in three opioid substitution programs in St. Gallen (125 methadone and 71 heroin recipients). Results were compared with another heroin substitution program in Bern (202 patients) and SCCS/SHCS data. RESULTS: Among the methadone/heroin recipients in St. Gallen, diagnostic workup of HCV was better than expected: HCV/HIV-status was unknown in only 1% (2/196), HCV RNA was not performed in 9% (13/146) of anti-HCV-positives and the genotype missing in 15% (12/78) of HCV RNA-positives. In those without spontaneous clearance (two thirds), HCV treatment uptake was 23% (21/91) (HIV-: 29% (20/68), HIV+: 4% (1/23)), which was lower than in methadone/heroin recipients and particularly non-IDUs within the SCCS/SHCS, but higher than in the, mainly psychiatrically focussed, heroin substitution program in Bern (8%). Sustained virological response (SVR) rates were comparable in all settings (overall: 50%, genotype 1: 35-40%, genotype 3: two thirds). In St. Gallen, the median delay from the estimated date of infection (IDU start) to first diagnosis was 10 years and to treatment was another 7.5 years. CONCLUSIONS: Future efforts need to focus on earlier HCV diagnosis and improvement of treatment uptake among patients in drug substitution programs, particularly if patients are HIV-co-infected. New potent drugs might facilitate the decision to initiate treatment.