PubMed · 9636864
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J E Edwards, K E Edwards. 1998. Reflections on studies in developing countries.. https://doi.org/10.1086/516371
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Members of the Mycobacterium avium complex are the most frequently encountered opportunistic bacterial pathogens among patients in the advanced stage of AIDS. Two clinical isolates of the same strain, numbers 397 and 417, were obtained from an AIDS patient with disseminated M. avium complex infection before and after treatment with a regimen of clarithromycin and ethambutol. To identify the biochemical consequence of drug treatment, the expression and chemical composition of their major cell wall constituents, the arabinogalactan, lipoarabinomannan, and the surface glycopeptidolipids (GPL), were critically examined. Through thin layer chromatography, mass spectrometry, and chemical analysis, it was found that the GPL expression profiles differ significantly in that several apolar GPLs were overexpressed in the clinically resistant 417 isolate at the expense of the serotype 1 polar GPL, which was the single predominant band in the ethambutol-susceptible 397 isolate. Thus, instead of additional rhamnosylation on the 6-deoxytalose (6-dTal) appendage to give the serotype 1-specific disaccharide hapten, the accumulation of this nonextended apolar GPL probably provided more precursor substrate available for further nonsaccharide substitutions including a higher degree of O-methylation to give 3-O-Me-6-dTal and the unusual 4-O-sulfation on 6-dTal. Further data showed that this alteration effectively neutralized ethambutol, which is known to inhibit arabinan synthesis. Thus, in contrast with derived Emb-resistant mutants of Mycobacterium smegmatis or Mycobacterium tuberculosis, which are devoid of a surface GPL layer, the lipoarabinomannan from resistant 417 isolate grown in the presence of this drug was not apparently truncated.
OBJECTIVE: To describe the epidemiologic and clinical features of AIDS-associated Kaposi's sarcoma (KS) in women compared with men. METHODS: In a retrospective study, within the Italian Cooperative Group on AIDS and Tumors (GICAT), we compared selected characteristics of 54 women and 108 men with AIDS-associated KS, matched by date of KS diagnosis and referral hospital. The chi2 test was used to test differences among proportions; the Kaplan-Meier method to estimate the survival time, and the Cox proportional hazard model was used to assess the role of gender, age, and CD4 cell count on death's risk. RESULTS: KS occurred at an earlier age (p = .001), was associated with a more severe immunodeficiency (p = .03), more advanced stages of HIV disease (p = .05), and had more aggressive presentation and course in women than in men. At KS diagnosis, women had a significantly increased proportion of visceral disease (p = .009), in particular pulmonary involvement (p = .002) and atypical sites of involvement (p = .008). The number of deaths due to KS was significantly higher (p = .01) in female patients. Both the higher proportion of visceral disease and of KS-related deaths observed in women did not change after adjusting for CD4 cell count and age. Women showed a decreased overall survival compared with men (8.9 and 14.4 months, respectively; p = .07), and the CD4 cell count at diagnosis significantly influenced survival. CONCLUSIONS: This study suggests that KS is more aggressive and life threatening in female than in male patients. This peculiar clinical behavior may reflect an inherently more aggressive biology of KS in women, possibly mediated by the level of immunodeficiency.
Five cases of Trypanosoma cruzi meningoencephalitis in HIV-infected patients are reported. All patients presented with mass lesions on head computed tomographic scan, trypanosomes in the cerebrospinal fluid and failure to respond to antitoxoplasmosis therapy. Benznidazole therapy was associated with clinical improvement in 1 patient. Another 4 patients had T cruzi identified in a peripheral smear. T cruzi needs to be considered in the differential diagnosis of HIV-infected patients with central nervous system mass lesions if they have a history of appropriate exposure.