Geography of intestinal permeability and absorption.
(33/30267)
BACKGROUND: Intestinal morphology and function vary geographically. AIMS: These functions were assessed in asymptomatic volunteers in European, North American, Middle Eastern, Asian, African, and Caribbean countries. METHODS: Five hour urine collections were obtained from each subject following ingestion of a 100 ml iso-osmolar test solution containing 3-0-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose after an overnight fast, to assess active (3-0-methyl-D-glucose) and passive (D-xylose) carrier mediated, and non-mediated (L-rhamnose) absorption capacity, as well as intestinal permeability (lactulose:rhamnose ratio). RESULTS: A comparison of results for subjects from tropical countries (n=218) with those resident in the combined temperate and subtropical region (Europe, United States, Qatar) (n=224) showed significant differences. Residents in tropical areas had a higher mean lactulose:rhamnose ratio and lower mean five hour recoveries of 3-0-methyl-D-glucose, D-xylose, and L-rhamnose, indicating higher intestinal permeability and lower absorptive capacity. Investigation of visiting residents suggested that differences in intestinal permeability and absorptive capacity were related to the area of residence. Subjects from Texas and Qatar, although comprised of several ethnic groups and resident in a subtropical area, showed no significant difference from European subjects. CONCLUSIONS: There are clearly demarcated variations in intestinal permeability and absorptive capacity affecting asymptomatic residents of different geographical areas which correspond with the condition described as tropical enteropathy. Results suggest the importance of environmental factors. The parameters investigated may be relevant to the predisposition of the indigenous population and travellers to diarrhoeal illness and malnutrition. Intestinal function in patients from the tropics may be difficult to interpret, but should take into account the range of values found in the asymptomatic normal population. (+info)
Community-level HIV intervention in 5 cities: final outcome data from the CDC AIDS Community Demonstration Projects.
(34/30267)
OBJECTIVES: This study evaluated a theory-based community-level intervention to promote progress toward consistent condom and bleach use among selected populations at increased risk for HIV infection in 5 US cities. METHODS: Role-model stories were distributed, along with condoms and bleach, by community members who encouraged behavior change among injection drug users, their female sex partners, sex workers, non-gay-identified men who have sex with men, high-risk youth, and residents in areas with high sexually transmitted disease rates. Over a 3-year period, cross-sectional interviews (n = 15,205) were conducted in 10 intervention and comparison community pairs. Outcomes were measured on a stage-of-change scale. Observed condom carrying and intervention exposure were also measured. RESULTS: At the community level, movement toward consistent condom use with main (P < .05) and nonmain (P < .05) partners, as well as increased condom carrying (P < .0001), was greater in intervention than in comparison communities. At the individual level, respondents recently exposed to the intervention were more likely to carry condoms and to have higher stage-of-change scores for condom and bleach use. CONCLUSIONS: The intervention led to significant communitywide progress toward consistent HIV risk reduction. (+info)
When do HIV-infected persons start with antiretroviral therapy? A retrospective analysis of patients' monitoring and treatment status in general practice, as compared with the 1991 Dutch HIV treatment guidelines.
(35/30267)
OBJECTIVE: We aimed to compare, in a sample of Amsterdam general practices, the monitoring and treatment status of HIV-infected patients according to the 1991 Dutch consensus guidelines for antiretroviral treatment of HIV-infection, which advise that therapy be started at a peripheral blood CD4+ cell count of < or = 300 x 10(6)/l in asymptomatic patients, or < or = 400 x 10(6)/l in symptomatic patients. METHOD: In 1994, data were collected from the records of all 511 HIV-infected patients registered in 14 Amsterdam general practices (20 doctors). The main outcome measures were the antiretroviral treatment status of all patients who were eligible for treatment, and the disease stage and CD4+ cell counts at the onset of therapy for patients who started treatment after publication of the 1991 guidelines. RESULTS: For 472 patients, data were available on CD4+ cell measurement status and disease stage. For 15.9% of patients, CD4+ cells had never been measured; most of them were asymptomatic. In 84.1 % of patients, CD4+ cells had been measured. Of the 8.9% of patients whose results were not known to GPs, 93% were treated by a specialist and 76% were symptomatic. Of the remaining 355 (75.2%) patients whose CD4+ count and disease status were known, 201 (56.7%) met the guideline criteria for treatment. Of these, 53.7% received treatment, 27.4% were never treated and 18.9% had discontinued treatment. Of the 67 patients who started treatment after publication of the guidelines, 36.2% of asymptomatic patients and 92.8% of symptomatic patients started later than the guidelines advised. CONCLUSION: In the population studied, we found a discrepancy between the 1991 treatment guidelines and the actual situation. In a substantial proportion of eligible patients, antiretroviral treatment was either not administered at all or was administered at a (very) late disease stage. This can only be attributed to physicians' and/or patients' attitudes towards antiretroviral treatment. Other studies confirm that a number of psychological factors may influence treatment decisions. The new combination treatment of HIV-infection requires an early start and compliance with the guidelines. The degree to which doctors and patients are willing and able to comply with the guidelines is an important factor to be taken into account, both in research and in the development of guidelines. (+info)
Determinants of the natural history of human immunodeficiency virus type 1 infection.
(36/30267)
Variation in the time to AIDS and duration of survival of human immunodeficiency virus (HIV)-1-infected persons was recognized early in the epidemic. Recent studies have indicated that the rate of viral replication, as manifest by the number of copies of HIV RNA per milliliter of plasma, is a major determinant of outcome in an infected person. The predictive power of the measurement of plasma HIV RNA copy number is enhanced by combining this result with the CD4 lymphocyte number. The determinants of the rate of viral replication are less clearly defined. Recent studies suggest that polymorphism of the chemokine receptors, required for cellular infection, plays a role in regulating the rate of viral replication. The subsequent adaptive evolution of HIV-1 to the host's immune response is a consequence of this dynamic of the virus. Complicating opportunistic infections also appear to enhance HIV-1 replication, while antiviral therapy, in contrast, can and does suppress viral replication. (+info)
Dual and recombinant infections: an integral part of the HIV-1 epidemic in Brazil.
(37/30267)
We systematically evaluated multiple and recombinant infections in an HIV-infected population selected for vaccine trials. Seventy-nine HIV-1 infected persons in a clinical cohort study in Rio de Janeiro, Brazil, were evaluated for 1 year. A combination of molecular screening assays and DNA sequencing showed 3 dual infections (3.8%), 6 recombinant infections (7.6%), and 70 (88.6%) infections involving single viral subtypes. In the three dual infections, we identified HIV-1 subtypes F and B, F and D, and B and D; in contrast, the single and recombinant infections involved only HIV-1 subtypes B and F. The recombinants had five distinct B/F mosaic patterns: Bgag-p17/Bgag-p24/Fpol/Benv, Fgag-p17/Bgag-p24/Fpol/Fenv, Bgag-p17/B-Fgag-p24/Fpol/Fenv, Bgag-p17/B-Fgag-p24/Fpol/Benv, and Fgag-p17/B-Fgag-p24/Fpol/Fenv. No association was found between dual or recombinant infections and demographic or clinical variables. These findings indicate that dual and recombinant infections are emerging as an integral part of the HIV/AIDS epidemic in Brazil and emphasize the heterogenous character of epidemics emerging in countries where multiple viral subtypes coexist. (+info)
HIV risk differences between African-American and white men who have sex with men.
(38/30267)
African-American men who have sex with men remain at disproportionately greater risk for contracting human immunodeficiency virus (HIV) infection. While high HIV seroincidence has been documented among homosexual African-American men, behavioral research has rarely studied the HIV risk issues confronting these men. This study assessed a sample of 253 men who have sex with men to determine if African-American (n = 79) and white (n = 174) men report different rates of HIV risk behaviors and differ in characteristics indicative of risk. African-American men who have sex with men were more likely to be HIV-seropositive, to report past treatment for gonorrhea and syphilis, and to have a recent unprotected sex partner known or believed to be HIV-seropositive. Multivariate analyses of covariance, controlling for group differences in age, education, and income, revealed that African-American men who have sex with men were less open about their sexual orientation, scored lower in HIV risk behavior knowledge, had more female sexual partners, and more frequently used cocaine in association with sex relative to white men who have sex with men. Human immunodeficiency virus prevention programs tailored to the needs and risk issues of African-American men who have sex with men are needed. (+info)
HIV-1 incidence among opiate users in northern Thailand.
(39/30267)
The incidence of human immunodeficiency virus type 1 (HIV-1) infection among opiate users was determined in a retrospective cohort of 436 patients with multiple admissions to the only inpatient drug treatment program in northern Thailand between October 1993 and September 1995. During 323.4 person-years of follow-up, 60 patients presenting for detoxification acquired HIV-1 infection, for a crude incidence rate of 18.6 per 100 person-years (95% confidence interval 14.4-23.9). All seroconverters were male. HIV-1 incidence varied by the current route of drug administration: 31.3 per 100 person-years for injectors and 2.8 per 100 person-years for noninjectors (smoking and ingestion). Significant differences were found by ethnicity: HIV-1 incidence was 29.3 per 100 person-years for Thai lowlanders and 8.5 per 100 person-years for hill tribes. Multivariate relative risk estimates showed that injecting opiates (vs. use by other routes), being unmarried, being under age 40 years, being a Thai lowlander, having a primary and secondary education, and being employed in the business sector were each independently associated with human immunodeficiency virus seroconversion. This HIV-1 incidence rate is double that reported for Bangkok and suggests that prevention and control programs for drug users need to be expanded throughout Thailand. Improved availability of more-effective treatment regimens and increased access to sterile injection equipment are needed to confront the HIV-1 epidemic among opiate users in northern Thailand. (+info)
Depletion of cutaneous peptidergic innervation in HIV-associated xerosis.
(40/30267)
Severe xerosis occurs in approximately 20% of human immunodeficiency virus seropositive patients. Changes in cutaneous innervation have been found in various inflammatory skin diseases and in xerotic skin in familial amyloid. We have therefore carried out a quantitative examination of the cutaneous peptidergic innervation in human immunodeficiency virus-associated xerosis. Immunohistochemistry and image analysis quantitation were used to compare total cutaneous innervation (protein gene product 9.5), calcitonin gene-related peptide, substance P, and vasoactive intestinal peptide peptidergic fibers, at two sites in the skin of human immunodeficiency virus-associated xerosis patients (upper arm, n = 12; upper leg, n = 11) and site-matched seronegative controls (upper arm, n = 10; upper leg, n = 10). Measurement of lengths of fibers of each type was carried out for each subject in the epidermis and papillary dermis, and around the sweat glands. Immunostained mast cells in these areas were counted. Epidermal integrity and maturation were assessed by immunostaining for involucrin. There were significant (Mann-Whitney U test; p < 0.02) decreases in total lengths of protein gene product 9.5 fibers in both epidermis/papillary dermis and sweat gland fields; of calcitonin gene-related peptide innervation in the epidermis/papillary dermis; and of substance P innervation of the sweat glands. There were no differences in the distribution of mast cells, or in the epidermal expression of involucrin. Depletion of the calcitonin gene-related peptide innervation may affect the nutrient blood supply of the upper dermis, and the integrity and function of basal epidermis and Langerhans cells. Diminished substance P innervation of the sweat glands may affect their secretory activity. Both of these changes may be implicated in the development of xerosis. (+info)