RESUMO
BACKGROUND: In Argentina, HIV diagnosis in adults is made using one or two enzyme immunoassay tests and a confirmatory test. These strategies may fail to identify infected individuals during early primary infection, which represents an important public health problem among groups with a high HIV incidence, such as men who have sex with men (MSM) (6.3% persons/year). The general objective of this study was to contribute to reducing HIV transmission among MSM through the identification of antibody-negative, nucleic acid-positive individuals. FINDINGS: A total of 1549 MSM were recruited for an HIV seroprevalence study. A total of 161 (10.4%) MSM were HIV-positive and 14 (0.9%) were indeterminate. Among the 1374 negative individuals, 16 (1.2%) exhibited reactive results in the screening assay. Indeterminate Western blot (WB) samples and negative WB samples (with discordant results in the screening) were analysed to detect HIV nucleic acid by viral load testing. Up to 23.1% of HIV-indeterminate WB samples and 7.1% of HIV-negative WB samples with discordant results in the screening assays had detectable nucleic acid. Overall, 14.8% of the samples with discordant or indeterminate results were identified as HIV-positive using direct diagnosis. With the identification of four new cases using the nucleic acid detection test, the HIV prevalence in MSM increased by 0.3% (from 10.4 to 10.7%). CONCLUSIONS: The results of this study suggest the importance of including nucleic acid detection in the HIV algorithm for MSM with HIV-indeterminate WB results and those with HIV-negative WB results and discordant results in screening assays, in order to decrease HIV transmission among this population with a high HIV prevalence and incidence.
Assuntos
DNA Viral/sangue , Anticorpos Anti-HIV/sangue , Soropositividade para HIV/diagnóstico , HIV-1 , Homossexualidade Masculina , Técnicas de Amplificação de Ácido Nucleico , RNA Viral/sangue , Adulto , Algoritmos , Argentina/epidemiologia , Análise Custo-Benefício , DNA Viral/genética , Diagnóstico Precoce , Soropositividade para HIV/epidemiologia , HIV-1/genética , Homossexualidade Masculina/estatística & dados numéricos , Humanos , Incidência , Masculino , Programas de Rastreamento , Prevalência , RNA Viral/genética , Carga ViralRESUMO
Both the human immunodeficiency virus (HIV) and environmental stress have been independently associated with decreased cognitive functioning in children. Given that they are also known to have a strong relationship with each other, the present study sought to test the hypothesis that children in conditions of high environmental risk would be at greater risk for the cognitive complications related to immunosuppression. A retrospective review was conducted to examine the records of 141 children treated at a large pediatric AIDS clinic from 1993 to 2000. CD4+ lymphocyte levels were recorded from laboratory results and IQ scores were recorded from routine psychological evaluations. Key indicators of environmental risk were collected and combined into one measure of overall environmental risk. Pearson product moment correlations were conducted to examine the relationship between environmental risk, age-adjusted CD4 and IQ. Results indicated a significant correlation between CD4 and IQ, with higher levels of immunocompetence predicting higher IQ scores. When subjects were dichotomized based on their environmental risk score, there was no relationship between CD4 count and IQ in the low environmental risk group. In contrast, CD4 was positively associated with IQ in the high environmental risk group. It is proposed that this may be due to gp120 levels in immunocompromised children being particularly toxic to the hippocampus and cortex under conditions of high stress but not so under conditions of low stress.
Assuntos
Complexo AIDS Demência/psicologia , Infecções Oportunistas Relacionadas com a AIDS/psicologia , Linfócitos T CD4-Positivos/imunologia , Transtornos Cognitivos/etiologia , HIV-1 , Complexo AIDS Demência/imunologia , Infecções Oportunistas Relacionadas com a AIDS/imunologia , Adolescente , Criança , Desenvolvimento Infantil , Pré-Escolar , Transtornos Cognitivos/imunologia , Feminino , HIV/imunologia , Humanos , Lactente , Testes de Inteligência , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores Socioeconômicos , Carga ViralRESUMO
Microglial phagocytosis plays a key role in neuroprotective and neurodegenerative responses of the innate immune system in the brain. Here we investigated the regulatory function of phosphoinositide 3-kinase γ (PI3Kγ) in phagocytosis of bacteria and Zymosan particles by mouse brain microglia in vitro and in vivo. Using genetic and pharmacological approaches our data revealed PI3Kγ as an essential mediator of microglial phagocytosis. Unexpectedly, microglia expressing lipid kinase deficient mutant PI3Kγ exhibited similar phagocytosis as wild-type cells. These data suggest kinase-independent stimulation of cAMP phosphodiesterase activity by PI3Kγ as a crucial mediator of phagocytosis. In sum our findings indicate PI3Kγ-dependent suppression of cAMP signaling as a critical regulatory element of microglial phagocytosis.
Assuntos
Encéfalo/enzimologia , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Microglia/enzimologia , Fagocitose/fisiologia , Animais , Encéfalo/citologia , Encéfalo/imunologia , AMP Cíclico/metabolismo , Metabolismo dos Lipídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/imunologia , Sistemas do Segundo Mensageiro/fisiologia , Transdução de Sinais/fisiologiaRESUMO
An HIV incidence estimation was performed among men who have sex with men (MSM), drug users (DUs), sex workers (SWs), and pregnant women (PW) from Argentina. Volunteers older than 18 years old without a previous HIV-positive diagnosis were included. HIV-positive samples were analyzed by the Serological Testing Algorithm for Recent HIV Seroconversion (STARHS) to estimate incidence. By partial RT-PCR and sequencing of the HIV pol gene, an HIV subtype and resistance profile were determined. A total of 12,192 volunteers were recruited from October 2006 to September 2008. A higher HIV prevalence was detected among trans SWs (33.9%, 38/112), male SWs (10.8%, 12/111), and MSM 10.4% (161/1549). HIV incidence estimates by STARHS was also higher on trans SWs (11.31 per 100 person-years), male SWs (6.06 per 100 person-years), and MSM (6.36 per 100 person-years). Antiretroviral primary resistant mutations were detected in 8.4% of the study group, with a higher frequency in female DUs (33.3%). Phylogenetic analysis showed that 124 (57.9%) samples were subtype B, 84 (39.3%) intersubtype BF recombinants, 5 (2.3%) subtype C, and 1 (0.5%) subtype F in the pol region. Subtype B was most commonly found in MSM and male SWs whereas the intersubtype BF recombinant was more prevalent in female DUs, female SWs, and PW. Given the high HIV prevalence and incidence found in most of these groups, monitoring the continuing spread of the HIV epidemic is essential for determining public health priorities, assessing the impact of interventions, and estimating current and future health care needs.
Assuntos
Antirretrovirais/farmacologia , Farmacorresistência Viral , Infecções por HIV/epidemiologia , HIV-1/classificação , HIV-1/efeitos dos fármacos , Adulto , Argentina/epidemiologia , Análise por Conglomerados , Feminino , Genótipo , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/genética , HIV-1/isolamento & purificação , Homossexualidade Masculina , Humanos , Incidência , Masculino , Filogenia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Trabalho Sexual , Transtornos Relacionados ao Uso de Substâncias/complicações , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genéticaRESUMO
A nuclease present in extracts of Bacillus subtilis inserts breaks in deoxyribonucleic acid (DNA) treated with the monofunctional alkylating agent, methyl methanesulfonate (MMS), but the nature of the sites within the alkylated macromolecule at which these breaks occur is not known. DNA extracted from B. subtilis cells that have recovered from MMS damage has lost its susceptibility to enzyme action. The recovery process is accompanied by some DNA breakdown and by the incorporation of thymidine. Some recovery from ultraviolet irradiation (UV) and MMS occurred in organisms starved for thymine or adenine, but UV recovery was stimulated by their addition. It is possible that MMS recovery proceeds by a process of excision and repair similar to, but not identical with, UV repair.
Assuntos
Alquilantes/farmacologia , Bacillus subtilis/efeitos dos fármacos , DNA Bacteriano/metabolismo , Ácidos Nucleicos , Bacillus subtilis/enzimologia , Bacillus subtilis/efeitos da radiação , Desoxirribonucleases/metabolismo , Desnaturação de Ácido Nucleico , Raios UltravioletaRESUMO
Overexpression of the cyclin-dependent kinase inhibitor p27 and exposure to low temperature (30 degrees C) represent two strategies to establish controlled proliferation processes for production of therapeutic proteins using Chinese hamster ovary (CHO) cells. Here we analyze the effect of growth inhibition on the quality of the human model glycoprotein SEAP (secreted alkaline phosphatase) for both strategies in monoclonal CHO-derived cell lines. Separation of purified SEAP samples using two-dimensional gel electrophoresis showed that production by proliferation-controlled CHO cultures did not alter the overall integrity of the product. Further, oligosaccharide profiles were compared using HPEC-PAD analysis. No differences were detectable between SEAP profiles obtained from p27 growth-arrested and proliferating cultures. However, production at 30 degrees C led to a significant increase in the degree of sialylation, an effect that is generally considered beneficial for the in vivo efficacy of protein therapeutics. In the production context presented here, SEAP expression is controlled by the tetracycline- (tet) repressible gene regulation system. Here we show low temperature-induced upregulation of the tetracycline-dependent transactivator (tTA). This induction has been shown by Northern blot analysis to occur at the mRNA level and is independent of the promoters driving the transactivator. We also describe a novel bottleneck in productivity at low temperature found in p27 growth-arrested CHO cells cultivated at 30 degrees C.
Assuntos
Fosfatase Alcalina/metabolismo , Técnicas de Cultura de Células/métodos , Proteínas Supressoras de Tumor , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/genética , Fosfatase Alcalina/isolamento & purificação , Animais , Northern Blotting , Células CHO , Proteínas de Ciclo Celular/farmacologia , Divisão Celular/fisiologia , Cricetinae , Inibidor de Quinase Dependente de Ciclina p27 , Eletroforese em Gel Bidimensional/métodos , Expressão Gênica/efeitos dos fármacos , Controle de Qualidade , RNA/metabolismo , Temperatura , Tetraciclina/farmacologia , Transativadores/metabolismo , Regulação para CimaRESUMO
Cyclin A is essential for regulating key transitions in the eukaryotic cell cycle including initiation of DNA replication and mitosis. This paper describes the characterization of a truncated cyclin A isoform (cyclin A(t)) in vitro in cultured mammalian cells and in mouse tissues. The presence of cyclin A(t) in specific cell types correlates with the ability of cell extracts to cleave in vitro translated cyclin A. In CHO-K1 cells, cyclin A processing to cyclin A(t) occurs at the N terminus; it does not involve the 26 S proteasome, nor could it be induced by conditional overexpression of the cyclin-dependent kinase inhibitor p27(Kip1). However, high cell densities lead to increased cyclin A(t) levels. Unlike full-length cyclin A, cyclin A(t) localizes to the cytoplasm, where it binds Cdk2. The data suggest that cyclin A processing occurs in vivo to yield an N-terminally truncated isoform by an unknown mechanism that is regulated by cell density. Differential subcellular localization may provide the first insights into the physiological role of cyclin A(t).
Assuntos
Quinases relacionadas a CDC2 e CDC28 , Ciclina A/química , Ciclina A/fisiologia , Proteínas Supressoras de Tumor , Animais , Western Blotting , Células CHO , Proteínas de Ciclo Celular/biossíntese , Linhagem Celular , Cricetinae , Ciclina A/biossíntese , Quinase 2 Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/metabolismo , Citoplasma/metabolismo , Citometria de Fluxo , Humanos , Camundongos , Testes de Precipitina , Ligação Proteica , Biossíntese de Proteínas , Isoformas de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Tempo , Transcrição Gênica , Células Tumorais CultivadasRESUMO
The Cushing/Whitney Medical Library began providing end-user access to MEDLINE in 1986 and switched to the OVID system in 1993. MEDLINE is a core service of the library, and the choice of delivery systems has had a significant impact throughout the Yale-New Haven Medical Center. This paper describes the user response to MEDLINE, discusses the effects of MEDLINE on other library services, and suggests ways in which technology, policy, and funding have influenced use. Yale's experience suggests that removing barriers in all three areas can dramatically expand the points of access, the number of users, and the amount of use with manageable effects on other library services.
Assuntos
Bibliotecas Médicas/organização & administração , Serviços de Biblioteca/tendências , MEDLINE/estatística & dados numéricos , Centros Médicos Acadêmicos , Connecticut , Custos e Análise de Custo/estatística & dados numéricos , Bibliotecas Médicas/economia , Serviços de Biblioteca/economia , Serviços de Biblioteca/estatística & dados numéricos , MEDLINE/economia , Interface Usuário-ComputadorRESUMO
In a review of 77 HIV positive children seen between 1981 and 1990, 32 were diagnosed as having lymphocytic interstitial pneumonitis). Four of the LIP group developed bronchiectasis, a finding not previously reported. The precise factors leading to the bronchiectasis are unclear. All patients had chronically consolidated lung with volume loss. A history of recurrent bacterial superinfection was not noted in any of the cases. With more cases of HIV positive children living longer, bronchiectasis, long known to occur in primary immunologic disorders, will probably be more frequently noted.