Joseph El-On

Leishmania donovani: action of excreted factor on hydrolytic enzyme activity of macrophages from mice with genetically different resistance to infection.

Abstract The effect of purified excreted factor from promastigotes of Leishmania donovani upon the activity of four enzymes from lysed peritoneal exudate cells of mice (C3H and C57BL) was determined. There was no demonstrable effect on acid phosphatase (EC3.1.3.2), β-glucuronidase (EC3.2.1.21), and N -acetyl-β-glucosaminidase (EC3.2.1.29), but β-galactosidase (EC3.2.1.23) was inhibited up to 72% after 3 hr of incubation at 37 C. Inhibition of C57BL mouse enzymes was not significantly different from that of C3H mice. Protamine sulfate combined with the highly negatively charged excreted factor of L. donovani to migrate as a single positively charged band on immunoelectrophoresis. Protamine sulfate also reversed the β-galactosidase inhibition, though this was without direct effect on the enzyme. The excreted factor did not change or lose its charge or antigenicity with regard to precipitating antibody, when incubated with extracts of mouse peritoneal exudate cells, splenocytes, or liver homogenate—irregardless of whether the mice had been infected with leishmaniasis for 1 or 2 weeks or were uninfected.

Leishmania donovani: physicochemical, immunological, and biological characterization of excreted factor from promastigotes

Abstract Leishmanial excreted factor (EF) from promastigote cultures was enriched from the crude product by differential precipitation with ammonium sulfate and perchloric acid, followed by column chromatography; and by boiling EF-antibody complex. Boiling destroyed the antibody, releasing the EF, which retained its ability to precipitate antibody. Enriched EF from Leishmania donovani promastigotes was found to be a highly negatively charged, carbohydrate-like material with a molecular weight approximating to 33,000, when monitored against a series of protein markers by gel filtration. Its ability to precipitate with antibody was unimpaired by boiling, lyophilization, pH changes from 1 to 11, treatment with high concentrations of NaCl, 10% phosphotungstic acid in 10% HCl, 0.6 M perchloric acid, 5% H 2 SO 4 , acetone, or dioxan. It did not absorb at wavelengths between 220 and 750 nm. Treatment with trypsin, Pronase, neuraminidase, and hyaluronidase did not affect its activity. Biochemical analysis showed that enriched EF contains carbohydrates but, at our level of detection, no protein, lipid, triglycerides, fatty acids, DNA, RNA, pentoses, amino sugars, sialic or uronic acid. Precipitation of EF by antibody was studied and the optimal molecular proportions for complete precipitation determined. EF-antibody complex, prepared at optimal proportions, and EF complexed with methylated bovine serum albumin, like EF alone, did not elicit antibody production in rabbits. EF in 0.5% phenol-saline elicited a delayed skin response of induration and erythema in guinea pigs cured of L. enriettii . Elevated temperature increased the release of EF from promastigotes, while the presence of trypsin acting at 37 C seemed to inhibit this effect slightly. Fractionation of mechanically broken promastigotes, by differential centrifugation and stepwise sucrose gradients, revealed a factor that precipitated rabbit antibody against whole promastigotes. This factor was associated with the soluble, organelle-free fraction and resembled EF when monitored by gel diffusion. This factor did not migrate when the complete extract from the broken promastigotes was run in immunoelectrophoresis. Boiling the extract for 5 min released a factor, which migrated to the anode. This factor appeared to be associated with another component in the promastigote, from which it dissociated on boiling. Boiling hamster tissues infected with leishmanial amastigotes, i.e., spleens containing L. donovani and epididymides containing L. tropica , also released factors similar to EF. These precipitated antibody in the same way, producing precipitation arcs that were continuous with those formed by EF from the homologous promastigotes. EF acted as a conditioner for culture promastigotes. Conditioned cultures showed maximal growth before similar, unconditioned cultures. However, both types of culture produced equal numbers of promastigotes per unit volume by the end of exponential growth.

Efficacy of ketoconazole in cutaneous leishmaniasis

Ketoconazole is a new antimycotic agent of special value in the management of systemic fungal infection (Heel 1982). In experimental studies in vitro, using human monocytes (Berman 1981), ketoconazole, especially hydrolized ketoconazole, was found to be highly effective against Leishmania major intracellular amastigotes. The oral administration of ketoconazole has recently been reported to give good results in cutaneous and mucocutaneous leishmaniasis caused by L. braziliensis, in an uncontrolled study (Urcuyo and Zaias 1982). In the present work, the efficacy of ketoconazole in the treatment of cutaneous leishmaniasis caused by L. major was examined. Eight patients, (seven males and one female, aged 16-41 years) with cutaneous leishmaniasis were treated. Diagnosis was made by protozoological examination of smears and cultures from several lesions as previously described (Even-Paz et al. 1982). All the patients were in good general health and had not received any previous topical or systemic treatment against leishmaniasis. Routine laboratory investigations, including ESR, CBC, SMAC-20 and urinalysis, were performed prior to starting ketoconazole therapy. All patients received 400 mg ketoconazole (Nizoral, Janssen, Beerse, Belgium) in one single dose daily with their breakfast for 28 days. No topical treatment was used. The patients were checked every 2 weeks by protozoological examination. Laboratory routine investigations were made again after the end of

Leishmania major: Excreted factor, calcium ions, and the survival of amastigotes

Mouse macrophages infected with amastigotes of Leishmania major contain about 40% more intracellular exchangeable calcium than control macrophages. Similar elevation of intracellular exchangeable calcium was observed in macrophages engulfing red blood cells coated with purified excreted factor from L. major. The rate of cytolysis of red blood cells coated with excreted factor was significantly lower than that of uncoated controls. Excreted factor strongly binds calcium; thus, the possible role of a microenvironment rich in calcium bound to excreted factor within the phagolysosome in protecting the amastigotes may be considered.

Ketoconazole in cutaneous leishmaniasis

shampoo was mainly used for scalp psoriasis, but lesions on the trunk, and in the axillae and groins have also been treated. Applications were made once a day for about i to 3 weeks and thereafter the frequency of application was reduced gradually. At each application, Selsun* was left on the skin surface for 15 min and then washed off. The overall results have been good and selenium sulphide shampoo is now frequently used by our psoriatic patients. Two severe cases have responded so quickly that we would like to report them in detail. Case I was a 41-year-old woman who had had psoriasis since 1970. Her scalp lesions increased in intensity between March and September 1986, when they had a tinea amiantacea appearance. Dithranol cream and high-potency corticosteroids had no effect. In March 1987 application of Selsun® once a day resulted in marked improvement within 5 days and almost complete healing in 8 days. Her inguinal psoriasis, which was also treated, improved in 4 days and cleared completely in 6 days. One month later the psoriasis remains healed on once or twice weekly maintenance treatment. Case 2 was a 40-year-old man who had had psoriasis for 28 years. Since 1982 his constant inguinal psoriasis had developed into a lichen simplex-like state with intense pruritus, lichenification and fissures. Topical corticosteroids had had very little effect. Application of Selsun® every other day relieved the pruritus completely in 6 days. One month later the pruritus had not returned, the lichenification had diminished and the plaques were paler. He retnains on once weekly maintenance therapy with Selsun*. Our clinical impression, gained during the last 3 years at various out-patient clinics for the treatment of psoriasis in the Stockholm area, is that selenium sulphide shampoo is beneficial for many psoriatics. Extraordinarily good responses in severe cases such as those reported here have strengthened this impression. The types of psoriasis that we have found most likely to respond favourably are: scalp psoriasis, where we commonly found a clearly diminishing need for other topical treatment; psoriasis of the slowly evolving, profuse dispersed guttate type, (in these patients typical lesions suggestive of pityrosporum foUiculitis are usually found); psoriasis of the inverse type and stable plaque psoriasis where itch is predominant; and in patients with expanding nummular psoriatic lesions, especially if pruritic. We believe a controlled study of topical selenium sulphide should be carried out to determine more exactly its potential value in the treatment of psoriasis and to further define its mode of action.

Inhibitory activity of sinefungin and siba (5′‐deoxy‐5′‐S‐isobutylthio‐adenosine) on the growth of promastigotes and amastigotes of different species of leishmania

The naturally occurring polyamlnes putrescine, spermidine and spermine are organic cations widely distributed in both procaryotic and eucaryotic organisms, including parasitic species, e.g., trypanosomes [ 1,2] and leishmanias [3,4]. In eucaryotic organisms, ornithine decarboxylase catalyses the conversion of ornithine into putrescine, while the synthesis of spermidine and spermine involves S-adenosylmethionine decarboxylase (fig.1). In Leishmunia, as in other organisms, polyamine

Topical treatment of recurrent cutaneous leishmaniasis with ointment containing paromomycin and methylbenzethonium chloride.

A propos de 2 observations. Resultats satisfaisants: amelioration clinique, disparition progressive des parasites et cicatrisation plus ou moins rapide: 85 j et 80 j respectivement. Le traitement est bien tolere et on nobserve pas de recidives (1 an de recul dans un cas)

Rifampicin Treatment of Cutaneous Leishmaniasis

ABSTRACT: In a small‐scale preliminary trial of oral rifampicin treatment was considered successful in six out of eight cutaneous leishmaniasis patients and probably effective in a seventh. The in vitro effect of rifampicin on leishmania organisms concerns inhibition of mitochondrial function or replication. The need for protozoological control in the assessment of treatment is stressed.

Efficacy of Rifampicin and Isoniazid in Cutaneous Leishmaniasis

ABSTRACT: Thirty‐nine patients with cutaneous leishmaniasis caused by Leishmania major were treated with rifampicin alone or in combination with isoniazid. No significant difference was found between these two therapeutic regimens, and about half of the patients were cured 2 months from the beginning of treatment. A review of rifampicin in cutaneous leishmaniasis is attached.

Leishmania tropica: Protective response in C3H mice vaccinated with excreted factor crosslinked with the synthetic adjuvant, muramyl dipeptide

Excreted factor, an immunosuppressive, acidic polysaccharide released by promastigotes of Leishmania tropica major in culture, was chemically crosslinked to the synthetic adjuvant muramyl dipeptide via the bifunctional imidoester dimethyladipimidate and poly-L-lysine. This conjugate, an uncrosslinked mixture of the components, or each of the components alone were injected one to three times into different groups of 8- to 12-week-old C3H mice. The mice were challenged 2 weeks after the last injection with 2 X 10(6) promastigotes of L. t. major in the base of the tail. For the next 5 weeks, the animals were monitored for number of parasites and size of the lesion which developed at the site of the challenge. Mice receiving one intraperitoneal injection of the conjugate were partially protected against challenge. Treated animals had higher initial parasite numbers but showed a more rapid clearing of the parasites. Furthermore, the treated animals developed smaller lesions that healed quicker than did those of the control groups. Multiple injections, or injection into a footpad, rather than intraperitoneally, reduced the ability to elicit a protective response. On the other hand, muramyl dipeptide injected into a footpad was partially protective. Antibody production to excreted factor, which was measured by indirect hemagglutination of sensitized erythrocytes, was detected after challenge in mice which had received conjugate or conjugate components. A delayed hypersensitivity reaction (measured by skin testing) was not detected in any of the groups prior to challenge.