Search

Chronic diarrhea, weight loss, and malabsorption can lead to considerable weight loss in patients with AIDS. African AIDS patients who suffer from these conditions are said to have the 'slim disease'. The genome of the AIDS virus has been demonstrated in intestinal tissue cells. However, the role of HIV in producing altered cells and clinical symptoms and illness has not been clarified. In patients with AIDS, cellular changes and signs and symptoms of disease have been attributed to malignancies, opportunistic infections, and inflammatory processes. Biopsies were taken from the jejunum (second portion of the small intestine) of 11 male, homosexual, HIV-positive patients with histories of diarrhea for more than 2 weeks. Three patients had confirmed AIDS by CDC (Centers for Disease Control) criteria, four had AIDS-related-complex (ARC), and one had generalized lymphadenopathy (swollen lymph nodes). The remaining three patients were asymptomatic except for mild, intermittent diarrhea. Examinations of the stools and tissues for acid-fast organisms, fungi, parasites and other pathogenic agents were negative. The tissue blocks of the biopsies were sectioned, coded, and examined. The microscopist was unaware of the patients' clinical histories. A variety of changes were noted in the specimens from HIV-infected patients. In the absence of any other causative agent, these microscopic tissue and cellular alterations suggest that the presence of HIV infection, itself, can produce tissue damage and the associated clinical conditions. The findings of specimens from control patients were within normal ranges. (Consumer Summary produced by Reliance Medical Information, Inc.)

ABSTRACTInvestigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected with Vibrio choleraeO1 and V. choleraeO139. The levels of nonspecific mediators of the innate defense system, i.e., prostaglandin E2(PGE2), leukotriene B4(LTB4), and lactoferrin (Lf), as well as myeloperoxidase (MPO), were elevated at the acute stage of the disease in stools obtained from both O1- and O139-infected adults and children. In the systemic compartment, the levels of Lf were increased after onset of disease, which in children remained elevated up to convalescence compared to the healthy controls. Increased concentrations of C-reactive protein were seen in the sera of adult cholera patients at the acute stage of infection. Elevated levels of the nitric oxide (NO·) metabolites (nitrite and nitrate [NO2-and NO3-]) were detected in plasma but not in urine. The activity of the scavenger of reactive oxygen species, superoxide dismutase, was higher in the plasma of adults immediately after the onset of disease, suggesting that an active scavenging of reactive oxygen species was taking place. The concentration of 8-iso-prostaglandin F2aremained unchanged in the systemic and mucosal compartments in the study subjects. After the recovery of patients from cholera, the concentration of the majority of the metabolites decreased to baseline levels by day 30 after the onset of infection. Immunohistochemical staining showed increased tissue expression of MPO, Lf, and inducible nitric oxide synthase at the acute stage in the duodenal biopsies of adults and rectal biopsies obtained from children with cholera. Very little difference was seen in the levels of the different inflammatory mediators in patients infected with V. choleraeO1 or the encapsulated V. choleraeO139. In summary, these results suggest that elevated concentrations of Lf, MPO, PGE2, LTB4, and NO·, as well as other metabolites, during the acute stage of the disease indicate that the innate defense system, as well as the inflammatory process, is activated in both adults and pediatric patients infected with V. choleraeO1 and O139.

Type strains of enteroaggregative Escherichia coliEAEC (17-2, serotype O3:H2; JM 221, serotype O92:H33), isolates from an adult and a child with diarrhoea and an asymptomatic colonised child were used to orally infect adult rabbits. The experimental animals were followed up and sacrificed at defined time periods. Colonisation of both small and large intestine was seen with all strains and isolates used. Isolates from an adult patient with diarrhoea (MP 27) and from an asymptomatic colonised child from the community (KM 1337) were recovered from the small intestine during the first week of infection and subsequently from the large intestine. A total of seven rabbits was infected with MP 27; while colonising the gastrointestinal tract of all seven rabbits, this isolate caused diarrhoea in only one. On ultrastructural examination, the rabbits infected with 17-2 showed invasion of lymphoid follicles. Bacteria were seen in intercellular spaces and within M cells, a finding that has not previously been described. It is clearly possible to produce gut colonisation by oral infection with EAEC in adult rabbits with normal flora.