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Leishmania Major Infection (leishmania + major_infection)

Distribution by Scientific Domains

Medical Sciences	83%

Selected Abstracts

Chronic antigen ingestion protects ovalbumin sensitized mice from severe manifestation of Leishmania major infection

PARASITE IMMUNOLOGY, Issue 11-12 2008
J. C. S. SALDANHA
SUMMARY In the present work, the development of experimental leishmaniasis was examined in sensitized BALB/c mice that were chronically fed with antigen. After an oral challenge with egg white solution, the ovalbumin (Ova)-sensitized mice showed an increase in serum anti-Ova IgE and IgG1 antibodies. Lesions induced by Leishmania major infection were reduced by the ingestion of Ova in sensitized mice, as assessed by reduced footpad growth, lower parasite loads and improved pathological outcome compared to sham sensitized mice. Moreover, such findings were connected to a shift to a Th1 response involving higher IFN-, production and serum levels of IgG2a anti- Leishmania antigens. The data appear to corroborate the suggestion that chronic ingestion of an antigen by sensitized mice modulates the immunological system through a shift in cytokine release, exhibiting a healing response and resistance to L. major infection. [source]

Schistosomiasis delays lesion resolution during Leishmania major infection by impairing parasite killing by macrophages

PARASITE IMMUNOLOGY, Issue 7 2002
Anne Camille La Flamme
Summary Infection of mice with Schistosoma mansoni delays the resolution of cutaneous lesions and parasitaemia during Leishmania major infection. In contrast, L. major infection does not appear to alter the course of schistosomiasis. Analysis of the cytokine responses in the draining lymph nodes (LN) indicates that, while L. major infection had no effect on schistosome-specific interleukin (IL)-4 production by mesenteric LN (MLN) cells, coinfection with S. mansoni resulted in decreased leishmania-induced interferon (IFN)-,, tumour necrosis factor-, and nitric oxide production by popliteal LN (PLN) cells 4 weeks after L. major infection. In addition, PLN cells produced higher levels of IL-4 4 weeks after L. major infection in coinfected mice. Finally, IFN-,-stimulated macrophages isolated from S. mansoni -infected mice were impaired in their ability to kill L. major after in vitro infection. These results suggest that pre-existence of a strong Th2 response-dominated infection can alter the responses to Th1-inducing pathogens at peripheral sites and impair Th1-mediated effector functions. [source]

Cutaneous leishmaniasis in a child treated with oral fluconazole

AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 3 2010
Angelo V Sklavos
ABSTRACT We report a case of cutaneous leishmaniasis in a 3-year-old West African girl with a 3-month history of multiple disfiguring, infiltrated, ulcerating and variably necrotic granulomatous plaques on the limbs and face that occurred after swimming in a river approximately 6 weeks before arriving in Australia. A diagnosis of cutaneous leishmaniasis, a protozoal zoonosis usually transmitted by the Phlebotomus species of sandfly, was considered. The clinico-pathological features were consistent with Leishmania major infection, known to be the major endemic species causing cutaneous leishmaniasis in the country of origin. Because of the presence of lesions on the face, active treatment was instituted. Continuing resolution of all lesions over 6 weeks was noted to occur with cribiform scarring with the use of oral fluconazole 150 mg daily. Oral fluconazole appears to be emerging as a therapy for uncomplicated cutaneous leishmaniasis, with advantages particularly important in paediatrics. [source]

Determination of intracellular efficacies of azithromycin against Leishmania major infection in human neutrophils in vitro

CELL BIOCHEMISTRY AND FUNCTION, Issue 1 2003
Mehmet Tanyuksel
Abstract Azithromycin is one of a new class of antibiotics known as azalides. Azithromycin has high tissue affinity and this feature is thought to be due to the presence of two basic tertiary amine groups. Leishmania major, one of the causative agents of cutaneous leishmaniosis, is an obligate intracellular parasite. In this in vitro study, the potential anti-leishmanial effect of azithromycin upon intracellular forms namely the amastigote of L. major in mice peritoneal macrophages was investigated. L. major promastigotes were propagated in RPMI-1640 supplemented with 20% fetal calf serum in the log phase. The percentage of phagocytosis and microbiacidal activity of azithromycin on macrophages was assessed in the control and study groups by fluorescence microscopy, using acridine orange. Our results showed that at all the concentrations used (0.05, 0.1, 0.3, 0.6,,g,ml,1) azithromycin had no inhibitory effect on the phagocytic capacity of mouse peritoneal macrophages. Although no significant difference was observed for leishmaniacidal activity between the study and the control groups at a concentration of 0.05,,g,ml,1 (p>0.05), a significant (p<0.05) increase in leishmaniacidal activity was detected at 0.1, 0.3 and 0.6,,g,ml,1. As a result, azithromycin does not provide any contribution to the phagocytosis of L. major promastigotes in macrophages in vitro, but it increases the intracellular killing rates of amastigotes. These results suggest that it has a potential anti-leishmanial effect, and may provide a significant advantage in the treatment of the disease. Copyright © 2002 John Wiley & Sons, Ltd. [source]