Detergent-free parasite transformation and replication assay for drug screening against intracellular Leishmania amastigotes.

Leishmaniasis is an infectious disease caused by protozoan species in the genera Leishmania and Endotrypanum. Current antileishmanial drugs are limited due to adverse effects, variable efficacy, the development of resistant parasites, high cost, parenteral administration and lack of availability in endemic areas. Therefore, active searching for new antileishmanial drugs has been done for years, mainly by academia. Drug screening techniques have been a challenge since the intracellular localization of Leishmania amastigotes implies that the host cell may interfere with the quantification of the parasites and the final estimation of the effect. One of the procedures to avoid host cell interference is based on its detergent-mediated lysis and subsequent transformation of viable amastigotes into promastigotes, their proliferation and eventual quantification as an axenic culture of promastigotes. However, the use of detergent involves additional handling of cultures and variability. In the present work, cultures of intracellular amastigotes were incubated for 72 h at 26 °C after exposure to the test compounds and the transformation and proliferation of parasites took place without need of adding any detergent. The assay demonstrated clear differentiation of negative and positive controls (average Z´ = 0.75) and 50% inhibitory concentrations of compounds tested by this method and by the gold standard enumeration of Giemsa-stained cultures were similar (p = 0.5002) and highly correlated (r = 0.9707). This simplified procedure is less labor intensive, the probability of contamination and the experimental error are reduced, and it is appropriate for the automated high throughput screening of compounds.

[Ovarian pregnancy. Case report and review of the subject]. / Embarazo ectópico ovárico. Caso clínico y revisión del tema.

A case of a 21-year-old single woman with an acute abdomen, vaginal bleeding and an anemic syndrome is presented. Physical examination and ultrasonography showed an enlarged uterus and a little mass in the right ovary, which was thought to be a fibroma versus pregnancy. Serum levels of chorionic gonadotropin were increased. Abundant black blood loose was found in the peritoneal cavity in the surgery performed. Through a wedge resection, a small hemorrhagic nodule was removed from the surface of the right ovary. Microscopic examination showed ovarian stroma, immature chorionic villi and intermediate extravillous trophoblast, which supported the diagnosis of ectopic ovarian pregnancy. This complication requires an opportune diagnosis, because it continues to be one of the leading risk factors in surgical gynecological emergencies and the first cause of maternal death during the first trimester of pregnancy. A brief review on the subject is presented.