51 resultados para Viral Fusion Proteins
Resumo:
The objective of the present study was to evaluate the serum viral load in chronically infected Hepatitis B virus (HBV) patients and to investigate the distribution of HBV genotypes in São Paulo city. Quantitative HBV-DNA assays and HBV genotyping have gained importance for predicting HBV disease progression, have been employed for assessing infectivity, for treatment monitoring and for detecting the emergence of drug resistance. Twenty-nine Brazilian patients with suspected chronic hepatitis B were studied, using real time PCR for viral load determination and direct DNA sequencing for the genotyping. The serology revealed chronic HBV infection in 22 samples. The HBV-DNA was positive in 68% samples (15/22). The phylogenetic analysis disclosed that eleven patients were infected with HBV genotype A, two with genotype F and two with genotype D. Thus, the genotype A was the most prevalent in our study.
Resumo:
This case report, along with the review presented, describes a patient diagnosed with acute viral hepatitis, who developed a framework of intense abdominal pain and laboratorial alterations compatible with acute pancreatitis. The association of acute pancreatitis complicating fulminant and non-fulminant acute hepatitis virus (AHV) has been reported and several mechanisms have been proposed for this complication, but so far none is clearly involved. As acute hepatitis is a common disease, it is important to stimulate the development of other studies in order to determine local incidence and profile of patients presenting this association in our environment.
Resumo:
The question of whether HIV-1 RNA in cerebrospinal fluid (CSF) is derived from viral replication in the central nervous system or simply reflects the transit of infected lymphocytes from the blood compartment has long been a matter of debate. Some studies found no correlation between CSF and plasma viral load, whereas others did. The lack of a correlation between the two compartments suggests that the presence of HIV-1 RNA is not simply due to the passive passage of the virus from blood to CSF but rather due to intrathecal replication. To evaluate the correlation between plasma and CSF HIV-1 RNA levels and to identify situations in which there is no correlation between the two compartments, seventy patients were prospectively studied. The association between CSF and plasma viral load was evaluated in the total population and in subgroups of patients with similar characteristics. A correlation between the CSF and plasma compartments was observed for patients undergoing highly active antiretroviral therapy (HAART), those with a CD4 T lymphocyte count lower than 200 cells/mm³, and those with increased CSF protein content. On the other hand, no correlation was observed for patients without adequate virological control, who had a CD4 count higher than 200 cells/mm³ and who did not use HAART. The correlation between the two compartments observed in some patients suggests that CSF HIV-1 RNA levels may reflect plasma levels in these subjects. In contrast, the lack of a correlation between the two compartments in patients who were not on HAART and who had normal CSF proteins and a poor virological control possibly indicates compartmentalization of the virus in CSF and, consequently, plasma-independent intrathecal viral replication.
Resumo:
The frequency of viral pathogens causing respiratory infections in children in the cities of Rio de Janeiro and Teresópolis was investigated. Nasal swabs from children with acute respiratory illnesses were collected between March 2006 and October 2007. Specimens were tested for viral detection by conventional (RT)-PCR and/or real time PCR. Of the 205 nasal swabs tested, 64 (31.2%) were positive for at least one of the viral pathogens. Single infections were detected in 56 samples, 50 of those were caused by RNA viruses: 33 samples tested positive for rhinovirus, five for influenza A, five for metapneumovirus, four for coronavirus and, three for respiratory syncytial virus. For the DNA viruses, five samples were positive for bocavirus and one for adenovirus. Co-infections with these viruses were detected in eight samples. Our data demonstrate a high frequency of viral respiratory infections, emphasizing the need for a more accurate diagnosis particularly for the emerging respiratory viruses. The fact that the emerging respiratory viruses were present in 9.2% of the tested samples suggests that these viruses could be important respiratory pathogens in the country.
Resumo:
The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.
Resumo:
Some infections can be the cause of secondary nephrotic syndrome. The aim of this study was to describe the experience of a Renal Disease Reference Clinic from Central Brazil, in which serological markers of some infectious agents are systematically screened in children with nephrotic syndrome. Data were obtained from the assessment of medical files of all children under fifteen years of age, who matched nephrotic syndrome criteria. Subjects were tested for IgG and IgM antibodies against T. gondii and cytomegalovirus; antibodies against Herpes simplex, hepatitis C virus and HIV; and surface antigen (HBsAg) of hepatitis B virus. The VDRL test was also performed. 169 cases were studied. The median age on the first visit was 44 months and 103 (60.9%) patients were male. Anti-CMV IgG and IgM were found in 70.4% and 4.1%, respectively. IgG and IgM against Toxoplasma gondii were present in 32.5% and 5.3%, respectively. Two patients were positive for HBsAg, but none showed markers for HIV, hepatitis C, or Treponema pallidum. IgG and IgM against herpes simplex virus were performed on 54 patients, of which 48.1% and 22.2% were positive. IgM antibodies in some children with clinical signs of recent infection suggest that these diseases may play a role in the genesis of nephrotic syndrome.