An Eight‐day Method for Screening Compounds against Leishmania donovani in the Golden Hamster*

Abstract

SYNOPSIS. Intracardial inoculation of 1–10 million L. donovani in 0.1 ml. of ground spleen suspension from an infected animal (hamster) results in a uniform rise of parasite numbers in the untreated animal over the first 8 days after the inoculation. This rise is highly consistent from experiment to experiment. Treatment is accomplished by parenteral injection of a compound for 6 successive days in this time interval, starting 24 hours after inoculation. No known active compound in proper dosage (sodium stibogluconate, pentamidine, fuadin) has failed to show a significant suppression of the expected rise in parasite numbers. No known inactive compound has had any effect on the course of the infection. The dosage‐response curve for the active compounds suggests that the method is a sensitive one. Since it takes only 8 days to complete, it is economical as well.

Vaccination Route That Induces Transforming Growth Factor β Production Fails To Elicit Protective Immunity againstLeishmania donovaniInfection

“…The parasite load was expressed in Leishman Donovan units, calculated by the following formula: number of amastigotes per 1,000 cell nuclei ϫ organ weight (milligram) (32).…”

Dendritic Cell-Based Immunotherapy Combined with Antimony-Based Chemotherapy Cures Established Murine Visceral Leishmaniasis

“…(through the tail vein) with freshly purified amastigotes of L. donovani (1 ϫ 10 7 / mouse). Splenic and liver parasite burdens were determined from impression smears after Giemsa staining and are reported as the total parasite load per organ using the formula: organ weight (milligrams) ϫ number of amastigotes per cell nucleus ϫ (2 ϫ 10 5 ) (17). To further evaluate whether these organs contained live parasites, in selected experiments homogenates of these organs were cultured for 2 wk after serial dilution (18).…”

Action of pentamidine-bound nanoparticles againstLeishmaniaon anin vivomodel

“…After Giemsa staining of the smears, the liver parasite burden (I) was calculated from the number of amastigotes/500 hepatocytes and related to the liver weight (P in mg), following the Stauber formula (Stauber L.A. et al, 1958).…”