Immune development in HIV-exposed uninfected children born to HIV-infected women.

Immunological and clinical findings suggestive of some immune dysfunction have been reported among HIV-exposed uninfected (HEU) children and adolescents. Whether these defects are persistent or transitory is still unknown. HEU pediatric population at birth, 12 months, 6-12 years were evaluated in comparison to healthy age-matched HIV-unexposed controls.

[Persistence of hepatitis A virus antibodies after primary immunization and response to revaccination in children and adolescents with perinatal HIV exposure].

Objective:: To assess possible factors associated with the loss of antibodies to hepatitis A 7 years after the primary immunization in children of HIV-infected mothers and the response to revaccination in patients seronegative for hepatitis A.

Methods:: Quantification of HAV antibodies by electrochemiluminescence was performed in 39 adolescents followed up at the Pediatric Aids Clinic of Federal University of São Paulo (Unifesp): 29 HIV-infected (HIV group) (median age: 12.8 years) and 10 HIV-exposed but non-infected (ENI group) (median age: 13.

Humoral and cellular immune responses to measles and tetanus: the importance of elapsed time since last exposure and the nature of the antigen.

Objective: This study aims to assess the cellular and humoral immune response pre- and post-vaccine rechallenge in healthy adults with previous exposure to measles (virus or vaccine) and different time intervals since last tetanus vaccine.

Methods: Humoral immunity was tested by ELISA, and cellular immunity was tested by intracellular interferon gamma detection after in vitro stimulation with antigens.

Results: While cellular immunity was comparable among vaccinated individuals and those who had measles, higher antibody levels were found in those who had the disease in the past.

Low CD4+ T-cell levels and B-cell apoptosis in vertically HIV-exposed noninfected children and adolescents.

Lymphocyte subsets, activation markers and apoptosis were assessed in 20 HIV-exposed noninfected (ENI) children born to HIV-infected women who were or not exposed to antiretroviral (ARV) drugs during pregnancy and early infancy. ENI children and adolescents were aged 6-18 years and they were compared to 25 age-matched healthy non-HIV-exposed children and adolescents (Control). ENI individuals presented lower CD4(+) T cells/mm(3) than Control group (control: 1120.

Persistence of vaccine immunity against hepatitis B virus and response to revaccination in vertically HIV-infected adolescents on HAART.

Humoral immune response to vaccine antigens is known to be reduced in perinatally HIV-infected children. Lymphocyte immunophenotyping, humoral immunity to hepatitis B after primary immunization and response to revaccination were evaluated in 40 HIV-infected adolescents on HAART and 23 healthy age-matched controls. Anti-HBs antibody levels >or=10 mIU/mL were found in 18/40 (40.

Chromatin supraorganization, DNA fragmentation, and cell death in erythrocytes of the rattlesnake, Crotalus durissus terrificus (Serpentes, Viperidae), infected with the protozoan, Hepatozoon spp. (Apicomplexa, Hepatozoidae).

Forms of the protozoan of the Hepatozoon genus are detected free in the circulation and also within some of the erythrocytes of infected snakes. In healthy snakes, DNA fragmentation and cell death usually affect a few circulating erythrocytes in agreement with the long life span expected for these cells. In the present study we investigated whether infection by Hepatozoon spp.

Strong HIV-1-specific T cell responses in HIV-1-exposed uninfected infants and neonates revealed after regulatory T cell removal.

Background: In utero transmission of HIV-1 occurs on average in only 3%-15% of HIV-1-exposed neonates born to mothers not on antiretroviral drug therapy. Thus, despite potential exposure, the majority of infants remain uninfected. Weak HIV-1-specific T-cell responses have been detected in children exposed to HIV-1, and potentially contribute to protection against infection.

Chromatin supraorganization, DNA fragmentation, and cell death in snake erythrocytes.

In nucleate erythrocytes of several vertebrate groups, the frequency and intensity of DNA fragmentation associated with programmed cell death vary considerably. Although hemoglobin efficiency may be related to erythrocyte life span, and hemoglobin types and erythrocyte life spans are assumed to vary in reptiles, no data on DNA fragmentation and chromatin organization as related to cell death exist for snakes. In the present study, chromatin supraorganization, DNA fragmentation, and cell death were investigated in four snake species (Crotalus durissus terrificus, Bothrops jararaca, Bothrops alternatus, and Bothrops neuwiedii), which differ in their geographical distribution and habitats, by using image analysis of Feulgen hydrolysis kinetics, the TUNEL assay, single-cell gel electrophoresis, and transmission electron microscopy.

Effects of crude extracts of Agaricus blazei on DNA damage and on rat liver carcinogenesis induced by diethylnitrosamine.

The effects of crude extracts of the mushroom Agaricus blazei Murrill (Agaricaceae) on both DNA damage and placental form glutathione S-transferase (GST-P)-positive liver foci induced by diethylnitrosamine (DEN) were investigated. Six groups of adult male Wistar rats were used. For two weeks, animals of groups 3 to 6 were treated with three aqueous solutions of A.