Gastrointestinal and cutaneous AIDS-related Kaposi's sarcoma: different activity of liposomal doxorubicin according to location of lesions.

Kaposi's sarcoma (KS) continues to be a frequent neoplasm in third world AIDS patients. We carried out a prospective study to evaluate the effectiveness of liposomal doxorubicin (LD) in gastrointestinal KS patients as well as its differential clinical activity depending on the location of the lesions. The study included 15 male AIDS patients aged between 25 and 35 years (mean: 27 years) with more than 25 cutaneous lesions and extensive gastrointestinal KS. They were treated with LD, 20 mg/m(2) every 21 days, for six cycles. Eleven (73%) of the patients obtained a complete response of the gastrointestinal KS lesions and four (27%) a partial response. Regarding cutaneous lesions, only two (13%) of the patients reached a complete response, six (40%) a partial response and seven (47%) stabilized their disease. By applying Fisher's test we found a significant difference (P < 0.00035) when comparing the effectiveness of LD in gastrointestinal lesions in relation to cutaneous lesions. We conclude that LD is more effective in gastrointestinal KS and can be recommended in patients in third world countries with extensive gastrointestinal lesions.

On the acid phosphatase isoenzymes existing in American Leishmania promastigotes.

1. Two partially purified acid phosphatase activities present in American Leishmania promastigote homogenates were characterized by biochemical methods. 2. One isoenzyme acts preferentially on p-nitrophenyl phosphate, is strongly inhibited by 30 mM alloxan, citrate, maleate, malonate and succinate, and strongly stimulated by 3 mM spermine. Its pI is 4.8. 3. The other isoenzyme acts preferentially on beta-glycerophosphate and is resistant to 30 mM alloxan, citrate, maleate, malonate and succinate and also to 3 mM spermine. Its pI is 5.7. 4. Both acid phosphatase isoenzymes have an optimum pH of 5.2, are tartrate-sensitive and strongly membrane-bound, as shown by differential centrifugation and density gradient equilibration. 5. Both isoenzymes were separated by using homogenates prepared in 2% Triton X-100, differential centrifugation, Sepharose 4B/CL-4B gel filtration, ion exchange chromatography and electrofocusing. After this procedure, they were still contaminated with several different proteins. 6. Purification was around 150-fold, with a 32% yield. 7. When these acid phosphatase activities were measured in total homogenates from 12 different Leishmania isolates, p-nitrophenyl phosphatase specific activity values were quite close; beta-glycerophosphatase-specific activity had around a 2-fold variation. 8. This variation was independent from taxonomic classification or infectivity of susceptible hosts.