Accelerated in vivo proliferation of memory phenotype CD4+ T-cells in human HIV-1 infection irrespective of viral chemokine co-receptor tropism.

CD4(+) T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i) that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5(+) cells, and (ii) that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4(+) compartment. To test these hypotheses we measured in vivo turnover rates of CD4(+) T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p) and disappearance (d*) rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143-569 cells/ul) participated. CCR5-expression defined a CD4(+) subpopulation of predominantly CD45R0(+) memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5(+) vs CCR5(-); healthy controls; P<0.01). Conversely, CXCR4 expression defined CD4(+) T-cells (predominantly CD45RA(+) naive cells) with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5(+)CD45R0(+)CD4(+) memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05), naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9) or X4-tropic (n = 4). Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively). Our data are most consistent with models in which CD4(+) T-cell loss is primarily driven by non-specific immune activation.

Protection versus pathology in aviremic and high viral load HIV-2 infection-the pivotal role of immune activation and T-cell kinetics.

BACKGROUND: Many human immunodeficiency virus (HIV)-2-infected individuals remain aviremic and behave as long-term non-progressors but some progress to AIDS. We hypothesized that immune activation and T-cell turnover would be critical determinants of non-progressor/progressor status. METHODS: We studied 37 subjects in The Gambia, West Africa: 10 HIV-negative controls, 10 HIV-2-infected subjects with low viral loads (HIV-2-LV), 7 HIV-2-infected subjects with high viral loads (HIV-2-HV), and 10 with HIV-1 infection. We measured in vivo T-cell turnover using deuterium-glucose labeling, and correlated results with T-cell phenotype (by flow cytometry) and T-cell receptor excision circle (TREC) abundance. RESULTS: Immune activation (HLA-DR/CD38 coexpression) differed between groups with a significant trend: controls

HIV-1 pathogenicity and virion production are dependent on the metabolic phenotype of activated CD4+ T cells.

BACKGROUND: HIV-1, like all viruses, is entirely dependent on the host cell for providing the metabolic resources for completion of the viral replication cycle and the production of virions. It is well established that HIV-1 replicates efficiently in activated CD4+ T cells, whereas resting CD4+ T cells are refractory to infection with HIV-1. A hallmark of T cell activation is the upregulation of glycolysis to meet the biosynthetic and bioenergetic needs of cell proliferation and the execution of effector functions by the secretion of cytokines. To date, it has remained unknown if HIV-1 requires the high glycolytic activity of activated T cells to support its replication. RESULTS: We report that in primary CD4+ T cells, the flux through the glycolytic pathway is increased upon infection with HIV-1. This increase in glycolytic activity does not occur in T cell lines when infected with HIV-1. By providing cells with galactose instead of glucose, the former being a poor substrate for glycolysis, we monitored the effect of preventing glycolysis in CD4+ T cells on virus replication cycle and cell fate. We observed that HIV-1 infected primary CD4+ T cells cultured in galactose have a survival advantage over those cultured in glucose and this coincides with reduced caspase 3 activation and apoptosis in cultures with galactose. T cell lines do not recapitulate this difference in cell death. Finally, we demonstrate that virion production is dependent on glycolysis as cultures containing galactose yield reduced amounts of HIV-1 virions compared with cultures containing glucose. CONCLUSIONS: The replication of HIV-1 in primary CD4+ T cells causes an increase in glycolytic flux of the cell. Glycolysis is particularly required for virion production and additionally increases the sensitivity of the infected cell to virus-induced cell death.

Comparing HIV-1 and HIV-2 infection: Lessons for viral immunopathogenesis.

HIV-1 and HIV-2 share many similarities including their basic gene arrangement, modes of transmission, intracellular replication pathways and clinical consequences: both result in AIDS. However, HIV-2 is characterised by lower transmissibility and reduced likelihood of progression to AIDS. The underlying mechanistic differences between these two infections illuminate broader issues of retroviral pathogenesis, which remain incompletely understood. Comparisons between these two infections from epidemiological, clinical, virologic and immunologic viewpoints provide a basis for hypothesis generation and testing in this 'natural experiment' in viral pathogenesis. In terms of epidemiology, HIV-2 remains largely confined to West Africa, whereas HIV-1 extends worldwide. Clinically, HIV-2 infected individuals seem to dichotomise, most remaining long-term non-progressors, whereas most HIV-1 infected individuals progress. When clinical progression occurs, both diseases demonstrate very similar pathological processes, although progression in HIV-2 occurs at higher CD4 counts. Plasma viral loads are consistently lower in HIV-2, as are average levels of immune activation. Significant differences exist between the two infections in all components of the immune system. For example, cellular responses to HIV-2 tend to be more polyfunctional and produce more IL-2; humoral responses appear broader with lower magnitude intratype neutralisation responses; innate responses appear more robust, possibly through differential effects of tripartite motif protein isoform 5 alpha. Overall, the immune response to HIV-2 appears more protective against disease progression suggesting that pivotal immune factors limit viral pathology. If such immune responses could be replicated or induced in HIV-1 infected patients, they might extend survival and reduce requirements for antiretroviral therapy.

Spontaneous attribution of underspecified belief of social partners facilitates processing shared information.

The main question of Theory of Mind research is not only how we represent others' mental states, but also how these representations influence our first-person interaction with our surrounding environment. A novel theory of belief files proposes that we should think about belief tracking as an online, spontaneous, and effortless mechanism giving rise to structured representations, thus easing the use of beliefs in behavior selection. Beliefs are formed by two different sub mechanisms: (1) opening an empty placeholder belief file, for a particular intentional agent, and (2) filling it up with mental content attributed to the agent. This theory opens the possibility of exploiting theory of mind abilities even in situations when we can attribute only underspecified mental contents to others. The goal of the present study was to provide a proof of concept test: whether spontaneous belief tracking starts effortlessly even when we do not know a partner's actual belief content. We created an object detection paradigm, where the visual access of a virtual agent to the object to be detected by the participant was manipulated. The agent getting access to the information for processing always preceded the participant getting access to it, resulting in the need of attributing belief without specified content in it. Our results have shown that participants detected the object with a reduced reaction time when the observed agent had visual access to the object's expected place compared to when the participant watched the same scenario, but the object's location remained occluded for the observed agent and thus was revealed only for the participant. This suggests that the information processing of humans speeds up when another agent has access to a piece of information as well. Thus, we do track agents' potential beliefs without knowing its actual content. This study contributes to our understanding of the effect of spontaneous computation of others' mental states on first-person information processing.

Measurement of ribosomal RNA turnover in vivo by use of deuterium-labeled glucose.

BACKGROUND: Most methods for estimation of rates of RNA production are not applicable in human in vivo clinical studies. We describe here an approach for measuring ribosomal RNA turnover in vivo using [6,6-(2)H(2)]-glucose as a precursor for de novo RNA synthesis. Because this method involves neither radioactivity nor toxic metabolites, it is suitable for human studies. METHODS: For method development in vitro, a lymphocyte cell line (PM1) was cultured in the presence of [6,6-(2)H(2)]-glucose. RNA was extracted, hydrolyzed enzymatically to ribonucleosides, and derivatized to either the aldonitrile tetra-acetate or the pentafluoro triacetate derivative of the pentose before GC-MS. We identified optimum derivatization and analysis conditions and demonstrated quantitative incorporation of deuterium from glucose into RNA of dividing cells. RESULTS: Pilot clinical studies demonstrated the applicability of this approach to blood leukocytes and solid tissues. A patient with chronic lymphocytic leukemia received [6,6-(2)H(2)]-glucose (1 g/kg) orally in aliquots administered every 30 min for a period of 10 h. When we analyzed CD3(-) B cells that had been purified by gradient centrifugation and magnetic-bead adhesion, we observed deuterium enrichment, a finding consistent with a ribosomal RNA production rate of about 7%/day, despite the slow division rates observed in concurrent DNA-labeling analysis. Similarly, in 2 patients with malignant infiltration of lymph nodes, administration of [6,6-(2)H(2)]-glucose (by intravenous infusion for 24 h) before excision biopsy allowed estimation of DNA and RNA turnover in lymph node samples. CONCLUSIONS: Our study results demonstrate the proof-of-principle that deuterium-labeled glucose may be used to analyze RNA turnover, in addition to DNA production/cell proliferation, in clinical samples.

Drinking patterns between men and women in two distinct Brazilian communities.

OBJECTIVE: A survey was conducted to compare gender differences in patterns of drinking in two stratified, urban and representative samples from two communities (B and RJr). METHOD: The Genacis (Gender, Alcohol, and Culture: an International Study) questionnaire was used. RESULTS: There were several significant differences in the demographics and patterns of alcohol use between these two samples. One had an older, more Catholic, educated, Caucasian population, with more women in the labor force. Data from B community showed that women and men had similar patterns of drinking. RJr had much higher use of alcohol among men, and almost 22% of those under 49 years old were binge drinkers. DISCUSSION: Access, smoking, income and having a heavy drinker partner were important risk factors for women's drinking. CONCLUSIONS: This study shows that when women's roles become more similar to men's, so do their drinking patterns.

Evidence for Altered Glutamine Metabolism in Human Immunodeficiency Virus Type 1 Infected Primary Human CD4+ T Cells.

Glutamine is a conditionally essential amino acid that is an important metabolic resource for proliferating tissues by acting as a proteinogenic amino acid, a nitrogen donor for biosynthetic reactions and as a substrate for the citric acid or tricarboxylic acid cycle. The human immunodeficiency virus type 1 (HIV-1) productively infects activated CD4+ T cells that are known to require glutamine for proliferation and for carrying out effector functions. As a virus, HIV-1 is furthermore entirely dependent on host metabolism to support its replication. In this study, we compared HIV-1 infected with uninfected activated primary human CD4+ T cells with regard to glutamine metabolism. We report that glutamine concentrations are elevated in HIV-1-infected cells and that glutamine is important to support HIV-1 replication, although the latter is closely linked to the glutamine dependency of cell survival. Metabolic tracer experiments showed that entry of glutamine-derived carbon into the citric acid cycle is unaffected by HIV-1 infection, but that there is an increase in the secretion of glutamine-derived glutamic acid from HIV-1-infected cells. Western blotting of key enzymes that metabolize glutamine revealed marked differences in the expression of glutaminase isoforms, KGA and CAG, as well as the PPAT enzyme that targets glutamine-derived nitrogen toward nucleotide synthesis. Altogether, this demonstrates that infection of CD4+ T cells with HIV-1 leads to considerable changes in the cellular glutamine metabolism.

[Influence of impulsivity, suicidality and serotonin genes on treatment outcomes in alcohol dependence]. / Wplyw impulsywnosci, sklonnosci samobójczych oraz genów ukladu serotoninowego na wyniki leczenia uzaleinienia od alkoholu.

AIM: The aim of the study was to identify risk factors of relapse by investigating relationships among suicidality, impulsivity, genetic markers of serotonin activity, and relapse in alcohol-dependent patients. METHODS: 90 alcohol dependent patients were followed for 12 months after the baseline assessment, which entailed evaluation of suicidality and impulsivity as well as collection of DNA samples. Polymorphisms of genes involved in the synthesis and activity of the serotonin system were analyzed. After 12 months from the first visit, the patients were re-contacted and interviewed for relapse. RESULTS: Relapse rates were significantly higher among patients with the history of suicidal attempts recorded at the baseline assessment. The genetic analysis showed that patients with the G/G genotype in the 5HTR1A gene were more likely to relapse, whereas patients with the C/C genotype were more likely to abstain. Moreover, there was a strong trend for an association between the G/G genotype and a history of suicide attempts. CONCLUSIONS: High level of suicidality may predict relapse in alcoholic patients. Altered serotonergic function increases the risk of a suicide attempt and may contribute to higher risk of relapse in alcohol dependent patients.

Integration of behavioral and physical health care for a medicaid population through a public-public partnership.

This article documents a unique organizational, legal, and financial partnership between a state, a university, a Medicaid managed health care plan, and a county to provide integrated mental health, substance abuse, and primary and specialty health care services to Medicaid, low-income, and indigent consumers in Washtenaw county, Michigan. Major regulatory, financial, and clinical changes were required within and among the various partners in the Washtenaw County Integrated Health Care Project. A new entity--the Washtenaw Community Health Organization--was created to implement the project. By sharing resources as well as financial risks, the state, the county, and the university have been able to provide ongoing integrated care to a vulnerable population of patients. Although resource intensive in conceptualization and implementation, the project can be viewed as a model for other states that face growing needy populations and decreasing Medicaid budgets.

Health care costs of seriously mentally ill patients enrolled in enhanced treatment.

Patients with psychosis (N = 866) were recruited into enhanced or standard Veterans Administration (VA) treatment. Enhanced programs, previously shown to be more effective, were less costly than VA standard care. Adjusted costs fell from $32,000-$55,000 (for the 1st year) to $20,000-$36,000 (for the 4th year). Costs were associated positively with schizophrenia, living in the Northeast region of the United States, and poorer baseline functioning.

Drinking patterns between men and women in two distinct Brazilian communities / Diferenças nos padrões de consumo de álcool entre homens e mulheres em duas comunidades brasileiras distintas

OBJECTIVE: A survey was conducted to compare gender differences in patterns of drinking in two stratified, urban and representative samples from two communities (B and RJr). METHOD: The Genacis (Gender, Alcohol, and Culture: an International Study) questionnaire was used. RESULTS: There were several significant differences in the demographics and patterns of alcohol use between these two samples. One had an older, more Catholic, educated, Caucasian population, with more women in the labor force. Data from B community showed that women and men had similar patterns of drinking. RJr had much higher use of alcohol among men, and almost 22 percent of those under 49 years old were binge drinkers. DISCUSSION: Access, smoking, income and having a heavy drinker partner were important risk factors for women's drinking. CONCLUSIONS: This study shows that when women's roles become more similar to men's, so do their drinking patterns.

OBJETIVO: Realizou-se um inquérito para comparar diferenças de gênero nos padrões de consumo de álcool em duas amostras urbanas, estratificadas e representativas de duas comunidades (B e RJr). MÉTODO: O questionário Genacis (Gênero, Álcool e Cultura: Um Estudo Internacional Gender, Alcohol, and Culture: An Internacional Study) foi utilizado. RESULTADOS: Houve várias diferenças significativas em dados sociodemográficos e de padrões de uso de álcool entre essas duas amostras. Uma delas tinha população mais velha, educada, católica, branca e mais mulheres na força de trabalho. Dados da comunidade B mostraram que mulheres e homens tiveram padrões similares de consumo de álcool. RJr teve uso de álcool mais alto entre homens e 22 por cento dos homens abaixo de 49 anos de idade tinham padrão de uso do tipo binge. DISCUSSÃO: O acesso, tabagismo, renda e ter um parceiro com consumo pesado de álcool foram fatores de risco importantes para o consumo das mulheres. CONCLUSÕES: Este estudo mostra que quando os papéis das mulheres se tornam similares aos dos homens, modificam seu padrão de consumo de álcool.

A importância da gravidade da dependência e do gênero para a evoluçäo de dependentes de drogas / The importancy of dependence severety and gender for the evolution of drugs dependents

O objetivo deste trabalho foi avaliar a evoluçäo de 109 pacientes dependentes de drogas (DSM-IV, APA 1994) depois de, pelo menos 1 ano de seguimento num programa ambulatorial da Faculdade de Medicina de Botucatu - UNESP. A todos os pacientes que vieram a se tratar foi oferecido um tratamento padräo baseado em prevençäo de recaídas (MARLATT & GORDON, 1985). As principais características dessa populaçäo de nível sócio-econômico médio e baixo, dos quais 71 por cento trabalham ou estudam, com uma taxa de desemprego de 17,5 por cento (nenhum morador de rua) e freqüência à escola de 7 anos em média: 78 por cento homens, idade entre 13 e 51 anos (média=22,8; dv=7,2), 73 por cento solteiros, 18 por cento casados e 9 por cento divorciados. Os níveis de gravidade da dependência foram: leve 6 por cento, moderados 22 por cento e graves 72 por cento conforme avaliaçäo clínica de acordo com o DSM-IV (APA, 1994). As principais drogas de dependência foram: crack (45 por cento), maconha (19,3 por cento), álcool (6,4 por cento), solventes (3,7 por cento), cocaína aspirada (15,6 por cento) e cocaína EV (11,9 por cento). Muitos dos pacientes (48 por cento) tinham outros diagnósticos psiquiátricos antes e durante o tratamento. Os resultados da evoluçäo mostraram uma melhora global em 54 por cento dos pacientes no uso de drogas, mais interesse na escola/trabalho e na melhora global da qualidade das relaçöes afetivas (confirmada pela família e pelo terapeuta); 16,5 por cento estavam abstinentes, e 37,6 por cento usando drogas muito menos (alguns drinks e/ou maconha semanalmente, em níveis que näo interferiram com trabalho/escola). Todos os outros (45,9 por cento) näo melhoraram ou permaneceram na mesma situaçäo. A análise de regressäo logística mostrou que a evoluçäo foi melhor para aqueles pacientes com dependência leve ou moderada (5,6 vezes mais chance) seguida por gênero masculino (4,2 vezes mais chance de ter uma boa evoluçäo comparado com as mulheres). As conclusöes säo no sentido da necessidade de se fazer a detecçäo precoce bem como terapêutica especial para mulheres visando atender às suas necessidades específicas