摘要:

SummaryIn this study, coreceptor usage of HIV-1 other than subtype B in relation to HIV-1 transmission from mother to child was investigated. Repeated sampling of 42 HIV-1–seropositive, asymptomatic women in Cameroon during the second and third trimesters of pregnancy, at delivery, and 6 months postpartum were performed.Envsubtyping was carried out from uncultured peripheral blood mononuclear cells (PBMCs) by heteroduplex mobility assay and, whenever necessary, by DNA sequencing. Virus isolates were tested for coreceptor usage on human cell lines—U87.CD4 and GHOST(3)—engineered to express stably CD4 and the chemokine receptors CCR1, CCR2b, CCR3, CCR5, or CXCR4, or the orphan receptors BOB/gpr15 or Bonzo/STRL33/TYMSTR. Transmission rate was 11.9%. Viruses were predominantly envelope subtype A and used CCR5 as coreceptor and, surprisingly, 4 of 28 (14.2%) isolates from mothers and 1 of 3 isolates from children used the orphan receptor Bonzo as well. In 2 transmitting mothers from whom sequential HIV-1 isolates were available, viral coreceptor usage evolved from CCR5 monotropic to CCR5/Bonzo dual tropic during pregnancy, and in 1 case transmission of this virus could be documented. Our data suggest that evolution of HIV-1 coreceptor usage to dual (or multi-) tropism may occur during pregnancy.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

SummaryAlthough CD4+T-cell activation has long been shown to promote infection and replication of simian immunodeficiency virus (SIV) and HIV, recent studies have documented that not all activated CD4+T cells from human and nonhuman primates are susceptible to infection with HIV/SIV, respectively. Activation of CD4+T cells with anti-CD3 + anti-CD28 conjugated beads led to induction of a state of anti-viral resistance to infection with strains of viruses that primarily use CCR5 as a coreceptor. The studies reported herein were designed to address the mechanism by which anti-CD3 + anti-CD28–induced stimulation in turn induced antiviral resistance. Results of these studies show that the anti-viral resistance induced by activation of CD4+T cells with anti-CD3 + anti-CD28 is primarily conferred by the synthesis of tumor necrosis factor-&agr; (TNF-&agr;), and highlight a unique regulatory role for TNF-&agr; in regulating synthesis of MIP-1&agr;, MIP-1&bgr;, and regulated-on-activation normal T-expressed and secreted cells, which contributes to this state of antiviral resistance to R5-tropic strains of HIV/SIV. However, while TNF-&agr; has a protective role in antiviral resistance of activated CD4+T cells to R5-tropic viruses, it enhances CXCR4 expression of CD4+T cells and mediates increased susceptibility to infection with X4-tropic strains of HIV and recombinant SIVs. The results of the studies reported herein also suggest that it is not the Th1 v/s Th2 cytokine profile but the mode of CD4+T-cell activation that dictates the synthesis of distinct cytokines which regulate the expression of chemokines and chemokine receptors which in turn regulate and confer susceptibility/resistance to R5 v/s X4-tropic HIV and SIV.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

HIV infection has now been consistently identified as the major cause of death in young Africans in both urban and rural areas. In Africa, several studies have defined the clinical presentation of HIV disease but there have only been a limited number of autopsy studies. Because of the scarcity of autopsy data and the possibility of differing type and frequency of opportunistic infections between different geographic locations we set out to study consecutive new adult medical admissions to a tertiary referral hospital in Nairobi and perform autopsies on a sample of HIV-1–positive and HIV-1–negative patients who died in the hospital ward. Basic demographic data were collected on all patients admitted to two acute medical wards over an 11-month period. Final outcome and final clinical diagnoses were recorded at discharge or death. An autopsy examination was requested if the patient died in the ward. Autopsy examination was performed in 75 HIV-1–positive (40 men, 35 women) and 47 HIV-1–negative (28 men, 19 women) adults who died in the hospital. This represented 48.4% of all HIV-1–positive deaths and 33.3% of all HIV-1–negative deaths. Tuberculosis (TB) and bacterial and interstitial bronchopneumonia accounted for 96% of the major pathology in patients found to be HIV-1–positive at autopsy. TB was present in half the HIV-1–positive autopsy patients and was disseminated in over 80% of cases. Meningeal involvement was present in 26% of those with disseminated TB. By contrast, TB was much less common in the HIV-1–negative patients at autopsy in whom bacterial bronchopneumonia and malignancies were the most common pathologies. The type pathology found in the HIV-1–positive autopsy patients was not different than that found in other areas in Africa so far studied.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundDisseminated infection withHistoplasma capsulatumandMycobacterium aviumcomplex (MAC) in patients with AIDS are frequently difficult to distinguish clinically.MethodsWe retrospectively compared demographic information, other opportunistic infections, medications, symptoms, physical examination findings and laboratory parameters at the time of hospital presentation for 32 patients with culture documented disseminated histoplasmosis and 58 patients with disseminated MAC infection.ResultsPositive predictors of histoplasma infection by univariate analysis included lactate dehydrogenase level, white blood cell (WBC) count, platelet count, alkaline phosphatase level, and CD4 cell count. By multivariate logistic regression analysis, those characteristics that remained significant included a lactate dehydrogenase value ≥500 U/L (risk ratio [RR], 42; 95% confidence interval [CI], 18.53–97.5;p< .001), alkaline phosphatase ≤300 U/L (RR, 9.35; 95% CI, 2.61–33.48;p= .008), WBC ≤4.5 × 106/L (RR, 21.29; 95% CI, 6.79–66.75;p= .008), and CD4 cell count (RR, 0.958; 95% CI, 0.946–0.971;p= .001).ConclusionsA predictive model for distinguishing disseminated histoplasmosis from MAC infection was developed using lactate dehydrogenase and alkaline phosphatase levels as well as WBC count. This model had a sensitivity of 83%, a specificity of 91%, and a misclassification rate of 13%.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveTo determine whether low-cost treatment of HIV using vitamin A would be beneficial, we examined the effect of vitamin A supplementation on morbidity of HIV-1 infected women.MethodsWe conducted a randomized, double blind placebo-controlled trial at King Edward VIII Hospital, in Durban, South Africa. In total, 312 HIV-seropositive pregnant women between 28 and 32 weeks' gestation were recruited into this trial. Patients were randomized to receive placebo or 5000 IU retinyl palmitate and 30 mg beta-carotene daily. At delivery of their children, patients received placebo or 200,000 IU retinyl palmitate. The main outcome measures were pre-and postnatal report of HIV-related symptoms.ResultsVitamin A did not confer any significant beneficial effect on the report of either HIV or pregnancy-related symptoms during the pre-or postnatal period.ConclusionIn this study of HIV-infected pregnant women, vitamin A supplementation given in doses designed to decrease mother-to-infant transmission did not result in significant beneficial effect on reported symptoms pre-or postnatally. Further investigation with larger number of participants, tailoring supplementation for specific clinical conditions, outside the context of pregnancy, is required to help clarify the possible clinical benefits of vitamin A.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

SummaryTrends in the vertical transmission rate of HIV and evolving antiretroviral usage between 1990 and 1998 within the Women and Infants Transmission Study were evaluated. A decline in mother-infant transmission was temporally associated with advances in therapy, especially when regimens including a protease inhibitor were included in the analysis.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

We estimated the annual number and cost of new HIV infections in the United States attributable to other sexually transmitted diseases (STDs). We used a mathematical model of HIV transmission to estimate the probability that a given STD infection would facilitate HIV transmission from an HIV-infected person to his or her partner and to calculate the number of HIV infections due to these facilitative effects. In 1996, an estimated 5052 new HIV cases were attributable to the four STDs considered here: chlamydia (3249 cases), syphilis (1002 cases), gonorrhea (430 cases), and genital herpes (371 cases). These new HIV cases account for approximately $985 million U.S. in direct HIV treatment costs. The model suggested that syphilis is far more likely than the other STDs (on a per-case basis) to facilitate HIV transmission. This analysis provides a framework for incorporating STD-attributable HIV treatment costs into cost-effectiveness analyses of STD prevention programs.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveTo compare characteristics of first-time needle exchange participants who enrolled at a mobile van–based exchange site versus a fixed pharmacy-based exchange site, in an area where both types of needle exchange programs were available.MethodsDemographic and drug use data were collected on needle exchange program participants on enrollment. Participants were included if they were first-time participants at the Baltimore needle exchange program between December 1997 and March 1999, and if their first visit was at either one van-based site or at one of two pharmacy-based sites. Descriptive statistics and inferences were based on the type of needle exchange into which participants enrolled.ResultsAmong 286 first-time participants, 92% were African American, 28% were women, 11% were currently employed, 55% completed high school, and the median age was 40 years. In multivariate analyses, van-based enrollment was more common among frequent injectors (odds ratio [OR] = 2.0), but less common among African American participants (OR = 0.21).ConclusionsOur data suggest that different venues for needle exchange program settings attract different types of drug injecting participants. This suggests that offering different venue types to reach participants with differing drug use patterns will be important to optimize risk reduction strategies.

ISSN:1525-4135    

出版商:OVID    

年代:2000

数据来源: OVID