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mapping of b-cell epitopes on the leishmania donovani 70 kda heat-shock protein. 19901707379
tricyclic drugs reduce proton motive force in leishmania donovani promastigotes.tricyclic compounds have been suggested as potential anti-leishmanial drugs. we have studied the effect of tricyclic drugs on several cellular functions in l. donovani promastigotes. imipramine inhibits proline transport and reduces delta ph and cellular atp at relatively high concentrations (ic50 = 50-80 microm). high concentrations of imipramine are also required to kill l. donovani promastigotes (ld50 greater than 50 microm). the presence of a chlorine atom in the side ring of either imiprami ...19901968745
a genetic map of mouse chromosome 1 near the lsh-ity-bcg disease resistance locus.isozyme and restriction fragment length polymorphism (rflp) analyses of backcross progeny, recombinant inbred strains, and congenic strains of mice positioned eight genetic markers with respect to the lsh-ity-bcg disease resistance locus. allelic isoforms of idh-1 and pep-3 and rflps detected by southern hybridization for myl-1, cryg, vil, achrg, bcl-2, and ren-1,2, between balb/canpt and dba/2npt mice, were utilized to examine the cosegregation of these markers with the lsh-ity-bcg resistance p ...19901970800
interactions between the human monocytic leukaemia thp-1 cell line and old and new world species of leishmania.the human promyelocytic thp-1 cell line has been found to support the growth of leishmania parasites. thp-1 cells, differentiated with retinoic acid, cease replication while remaining in suspension. 72 +/- 8% of thp-1 cells became infected after inoculation with promastigotes of several old and new world leishmania species. the resulting amastigotes (19 +/- 5 per infected cell) were easy to harvest, capable of reinfecting cultures of normal human cells and, in the case of l. major and l. infantu ...19901971494
interclonal variations in molecular karyotype in leishmania infantum imply a 'mosaic' strain structure.the molecular karyotypes of 36 clones derived from 8 strains of leishmania infantum were examined by pulsed-field gel electrophoresis. although there appeared to be a high degree of genetic relatedness between the clones and the parent strain, a limited degree of polymorphism was noted in 50% of the clones, expressed mainly as the presence of an additional chromosome or as a chromosome size modification. repeated subcloning in one strain showed that chromosomal rearrangements could occur during ...19901971914
experimental transmission of leishmania infantum by the bite of phlebotomus perniciosus from switzerland.the possible role of the sandfly phlebotomus perniciosus in the transmission of leishmania infantum in southern switzerland was investigated. it was found that the syrian golden hamster (mesocricetus auratus) could be infected by the bite of experimentally infected p. perniciosus females from canton ticino, in southern switzerland. this showed that this sandfly species could indeed be a vector for l. infantum in this area. however, as the population density of p. perniciosus is relatively low in ...19901973022
suppression of the hepatic microsomal cytochrome p-450 dependent mixed function oxidase activities in golden hamster during leishmania donovani infection.experimental infection of golden hamsters with leishmania donovani caused significant alterations in the hepatic microsomal mixed function oxidase system. gross examination of liver indicated hepatomegaly. microsomal protein contents were only marginally elevated. cytochrome p-450 as well as haem contents were significantly decreased and it directly correlated with the degree of infection. cytochrome b5 exhibited elevation at lower degrees of infection which came down to control levels at the pe ...19892594607
hydrazide antidepressants possess novel antileishmanial activity in vitro and in vivo.the hydrazide monoamine oxidase inhibitor antidepressants possess a novel antiparasitic action against visceral and cutaneous strains of leishmania. in vitro, phenelzine was the most active compound tested, while in vivo, nialamide was more potent, and was also effective when applied topically to cutaneous lesions. despite the coincidence of tricyclic antidepressants also possessing antileishmanial activity, the evidence suggests that the antiparasitic action of the hydrazides is unrelated to ei ...19892596901
evaluation of antileishmanial activity of trans-aconitic acid.taa, an inhibitor of the enzyme aconitase, inhibits the growth of l. donovani promastigotes. morphogenic transformation of the amastigote to the promastigote (table; see text) form in vitro was also inhibited by 2 mm taa. taa also reduced multiplication of the parasite in macrophage culture. in the hamster model of leishmania, taa significantly reduced the parasitic burden of liver. in acute toxicity tests with balb/c mice no deaths were recorded even at a dose level of 2 g/kg body wt/day.19892597432
successful in vitro isolation and cultivation of italian dermotropic strains of leishmania infantum sensu lato. 19892603211
the effect of liposome-entrapped desferrioxamine on leishmania donovani in vitro.desferrioxamine was tested in vitro for activity against promastigotes of leishmania donovani. in addition, the effects of liposome-encapsulated desferrioxamine and free desferrioxamine on macrophages infected with amastigotes of l. donovani were compared. the drug was added to the culture medium for three days, and the results were compared with several controls; the drug solvent, empty liposomes, and desferrioxamine which had been re-ferrated with an equimolar concentration of ferric ammonium ...19892604473
two new techniques for quantitative determination of leishmania amastigotes. 19892609370
didelphis marsupialis, an apparent wild reservoir of leishmania donovani chagasi in colombia, south america. 19892609371
characterization of a mutant clone of leishmania donovani deficient in folate transport. 19892610143
interstitial nephritis and glomerulonephritis in visceral leishmaniasis in a dog. a case report.renal involvement characterized by interstitial nephritis and glomerulonephritis is reported in a case of visceral leishmaniasis in a dog. focal interstitial inflammatory infiltrates including lymphocytes and plasma cells together with collections of histiocytes containing leishmania donovani organisms were found in the renal cortex. the glomeruli showed diffuse mesangial cell proliferation, thickening of the capillary wall and focal, segmental glomerulosclerosis. by electron microscopy, finely ...19892611027
clinico-epidemiological profiles of post-kala-azar dermal leishmaniasis in varanasi.twenty-seven cases of post kala-azar dermal leishmaniasis (p. k. d. l.) were detected in an endemic focus of kala-azar in sujabad village in varanasi distt. male-female ratio of cases was 4.4:1. majority (66.6 per cent) of cases had macular lesions. histopathology of one case showed leishmania donovani (l. d.) bodies. densities of sand fly were more in pockets where p. k. d. l. cases were detected. all the 13 cases, which were treated with sodium antimony gluconate, responded well to therapy.19892614049
a comparison of the direct agglutination test and enzyme-linked immunosorbent assay in the sero-diagnosis of leishmaniasis in the sudan.the sensitivity and specificity of the direct agglutination test (dat) and the enzyme-linked immunosorbent assay (elisa) were compared for the sero-diagnosis of visceral (vl) and cutaneous (cl) leishmaniasis in sudanese patients. all the sera from parasitologically confirmed cases of vl were positive in both elisa and dat. some minor discrepancies were apparent between the two tests in patients with clinical signs of vl, but in whom vl was not confirmed parasitologically. in parasitologically co ...19892617579
leishmania infecting man and wild animals in saudi arabia. 5. diversity of parasites causing visceral leishmaniasis in man and dogs in the south-west.kala-azar (vl), mainly affecting infants and young children, is being increasingly reported in the south-west of saudi arabia, 305 cases being diagnosed in 1988. most cases arise in scattered locations in the foothills west of the asir mountains at altitudes between about 500 and 1000 m, although case clusters are apparent in some villages. some cases also occur between the foothills and the red sea coast. the incidence in the south-west was calculated to be of the order of 6 to 8/10,000 populat ...19892617600
antileishmanial effects of clofazimine and other antimycobacterial agents.in the search for more effective alternatives to the presently-used antileishmanial drugs, the activity of the major groups of antimycobacterial compounds has been examined, both in vitro and in animal models of infection. in vitro, clofazimine was the most active compound tested, with a mean ed50 of 2.3 mg l-1 against leishmania mexicana amazonensis, 1.4 mg l-1 against l. donovani and 0.5 mg l-1 against l. major. other active compounds were the thiosemicarbazone, thiambutosine, and salinazid, a ...19892619361
leishmania donovani donovani and leishmania donovani chagasi as antigens in a direct agglutination assay for the diagnosis of kala-azar.the need for a reliable method for the immunological diagnosis of kala-azar is imperative. leishmania donovani donovani and l. donovani chagasi culture promastigotes were compared as antigens in a direct agglutination test (dat) for the diagnosis of visceral leishmaniasis in brazil. both antigens were successfully employed for the dat, showing 100% sensitivity and greater than 98% specificity when used to test sera from brazilian and african kala-azar, chagas' disease, malaria, filaria and syphi ...19892620171
exploration of antileishmanial activity in heterocycles; results of their in vivo & in vitro bioevaluations.a total of 51 imidazoles, pyrroles, quinolines and isoxazolines compounds were screened for antileishmanial activity in vivo and in vitro, using leishmania donovani as the test parasite. the screening revealed hitherto unknown antileishmanial activity in these heterocycles. three of the compounds screened (one belonging to isoxazoline series and two from pyrrole series) showed significant anti-leishmanial activity, ranging from 86-91 per cent inhibition in hamsters. when tested in vitro, using m ...19892620947
lsh: origins and growth of a cottage industry. 19892623362
[leishmania infantum mon-24 cutaneous leishmaniasis observed in grassa (alpes-maritimes) in a tunisian child]. 19892624379
[studies on protective monoclonal antibodies to leishmania donovani].kala-azar is increasing in incidence in some endemic areas of china, such as provinces of sichuan and gansu. monoclonal antibodies have been shown to interfere with the cutaneous leishmaniasis infection in the experimental animals. we have now raised mcab against membrane antigen of promastigotes of l. donovani canine isolate (the pathogen of visceral leishmaniasis). in this paper we report 3 mcab which inhibit the growth of promastigotes in vitro culture by incorporation of 3h-thymine deoxyribo ...19892625325
mechanism of complement-independent and antibody-mediated killing of leishmania donovani promastigotes.immune serum raised against flagellar fraction of leishmania donovani isolate ur6 has profound lethal effect on the in vitro growth of the parasite. lethal effect of immune serum was also examined using two other isolates of l. donovani, namely dd8 and ag83. it was observed that immune serum is equally effective against ur6 and dd8 but has no effect on ag83 promastigotes. parasite killing is mediated by leishmania-specific antibodies in the absence of complement or any other factors present in r ...19892628259
observations on human bone-marrow for leishmania donovani.during the recent epidemic in north bihar, a total of 65 cases which were clinically designated as kala-azar had been subjected to bone-marrow aspiration from the iliac crest, out of which the l.d. body was demonstrated in 55 cases (84.61 per cent). culture analysis of bone-marrow on modified tobie's medium, revealed that ten cases (15.39 per cent) which were negative for l.d. body did not show any leptomonads, whereas out of 55 l.d. body positive cases, the promastigote forms developed in 22 ca ...19892632416
[eco-epidemiology of visceral and cutaneous leishmaniasis in the yemen arab republic. i. presence, in sympatric condition, of leishmania infantum and leishmania donovani complexes].in complement to a previous survey, the authors proceed to the analysis of strains isolated from visceral human and canine leishmaniasis. finally, among eight human strains isolated and identified with an enzymatic method, seven belong to the leishmania donovani complex and one to the l. infantum complex. the l. donovani complex is represented by the mon-31 and mon-83 zymodem. the first one is also present in saudi arabia and ethiopia. the second one, corresponding to a small variant, pleads for ...19892633874
[eco-epidemiology of visceral and cutaneous leishmaniasis in the arab republic of yemen. ii. a survey using intradermal reaction to leishmanin in a zone of mixed infestation with leishmania tropica, l. donovani and l. infantum].frequency distribution of leishmanin test survey in dhamran valley around taez (yemen arab republic) is reported. it was carried out on 174 school children from 6 to 12 years old. three schools located at 950 m, 1,100 m and 1,430 m of altitude were visited. the maximum of positivity is observed in the lower range where l. tropica, l. donovani and l. infantum are rife. in the upper valley, where cutaneous leishmaniasis is rare and visceral leishmaniasis absent, the rate of positivity is a little ...19892633875
[visceral leishmaniasis in patients with aids. description of 2 cases].cell-mediated immunity plays a pivotal role in the pathogenesis and in the recovery mechanisms of visceral leishmaniasis (v.l.). this disease, observed in two patients with aids, has peculiar anatomical and clinical characteristics and it is usually characterized by a severe clinical course. in addition, v.l. has been proposed to be included among the relevant infections for the case definition of aids. we describe two cases of v.l. occurred in association with aids. the most relevant characteri ...19892635290
evaluation of antibody responses in american visceral leishmaniasis by elisa and immunoblot.american visceral leishmaniasis (avl) is an important disease among children of northeast brazil. in order to characterize antibody responses during avl, sera of hospitalized patients were analyzed by elisa and western blot using a leishmania chagasi antigen preparation. the elisa was positive (absorbance greater than or equal to 0.196) at a serum dilution of 1:1024 in all patients at presentation, and fell to ward control levels over the following year. only one of 72 control subjects tested po ...19892635749
quantitative grading of leishmania donovani amastigotes related to age of kala-azar patients.out of 370 leishman donovan bodies positive bone-marrow smears, maximum belonged to grade 1 + (42.4 per cent) and the least to grade 5 + (1.6 per cent). persons belonging to 0-20 years age group were found in be statistically more susceptible to leishmania infection as compared to persons above 20 years of age (p less than .01). the disease was least common in persons above 40 years (3.5 per cent) of age. parasite load was found to be highest in 0-20 years group irrespective of grades of leishma ...19892638374
leishmania donovani: immunochemical localization and secretory mechanism of soluble acid phosphatase.monoclonal antibodies specific for the soluble, secreted acid phosphatase (ec 3.1.3.2) of leishmania donovani were used to investigate the localization of this enzyme in extracellular promastigotes and intracellular amastigotes. indirect immunofluorescence showed a weak general staining in the promastigote cytoplasm, together with strong fluorescence in the flagellar reservoir. immunofluorescence studies on u937 cells infected in vitro with l. donovani showed that the pathogenic amastigote stage ...19892649391
methylglyoxal-catabolizing enzymes of leishmania donovani promastigotes.methylglyoxal is a toxic metabolite with growth inhibitory properties against leishmania donovani promastigotes. we have shown in the present study that both log and stationary phase promastigotes of l. donovani can catabolize methylglyoxal to d-lactate as the major end product. the specific activity of methylglyoxal reductase was found to be the highest of all the catabolic enzymes. in contrast, the anabolic pathway for methylglyoxal could not be detected. moreover, when control promastigotes o ...19892668758
visceral leishmaniasis (kala-azar) as an opportunistic infection in patients infected with the human immunodeficiency virus in spain.in an area endemic for visceral leishmaniasis, 16 patients with human immunodeficiency virus (hiv) infection developed the disease. all belonged to populations at risk for aids (15 were intravenous drug abusers). five patients fulfilled the criteria for full-blown aids, and two more fulfilled them after diagnosis of leishmaniasis. all presented with the classic manifestations of visceral leishmaniasis, but leishmania serology was negative in 15 patients (93%). leishmania donovani amastigotes wer ...19892672242
amastigote stage-specific monoclonal antibodies against leishmania major.monoclonal antibodies were produced against gamma-irradiated amastigotes of leishmania major. five antibodies (t16 through t20) were selected which reacted in enzyme-linked immunoassays with the intracellular stage of the parasite. these antibodies did not react with promastigotes of l. major or leishmania donovani. one of the monoclonal antibodies (t16) reacted with amastigotes of leishmania mexicana amazonensis and l. donovani. western blotting (immunoblotting) and immunoprecipitation of [35s] ...19892680982
in vitro action of platinum (ii) and platinum (iv) complexes on trypanosoma cruzi and leishmania donovani.the in vitro activities of 22 neutral pt(ii) complexes, 4 pt(iv) complex salts, and one pt(ii) complex salt on epimastigote forms of trypanosoma cruzi and promastigote forms of leishmania donovani were studied. only 2 out of the 18 complexes with cis-pt(ddh)xn structure completely inhibited the growth of the epimastigote forms of t. cruzi and the promastigote of l. donovani. against t. cruzi the cis-pt(l)n(cl)2 complexes showed no activities, but the complex in which the (l) ligand was stilbamid ...19892684173
application of a direct agglutination test for detection of specific anti-leishmania antibodies in the canine reservoir.a direct agglutination test (dat) for detection of visceral leishmaniasis in humans has been developed. in this study, it was evaluated for applicability to detection of infections in dogs, a reservoir species. the reliability of the test was improved by treating the test sera with 0.2 m 2-mercaptoethanol and incubating them at 37 degrees c. sensitivity was 100% and specificity was 98.9% when the test was used on serum samples from 220 dogs, including 26 with parasitologically confirmed canine l ...19892685025
27th forum in immunology. the macrophage resistance gene lsh/ity/bcg. 19892696046
the macrophage resistance gene lsh/ity/bcg. 19892696047
a comparison of genetic linkage maps surrounding the lsh/ity/bcg disease resistance locus. 19892696048
a reverse genetics approach to bcg/ity/lsh gene cloning. 19892696049
role of lsh in regulating macrophage priming/activation. 19892696053
lsh, antigen presentation and the development of cmi. 19892696054
ity and after. 19892696055
genetics and molecular pathogenesis of legionella pneumophila, an intracellular parasite of macrophages.in addition to providing a powerful approach for identifying bacterial factors required for full infectivity and disease production, genetic analysis of legionella pathogenesis should also lend critical insight into the biology of the macrophage and into the pathogenesis of other intracellular parasites. the interaction between l. pneumophila and the macrophage exhibits many features found in a wide variety of prokaryotic and eukaryotic intracellular human pathogens. for example, binding to comp ...19892696860
purification and characterization of the adenine phosphoribosyltransferase and hypoxanthine-guanine phosphoribosyltransferase activities from leishmania donovani.the adenine phosphoribosyltransferase (aprtase) and hypoxanthine-guanine phosphoribosyltransferase (hgprtase) activities from promastigotes of leishmania donovani have been purified to homogeneity using ammonium sulfate precipitation, deae-cellulose exclusion, and either amp-agarose (aprtase) or gtp-agarose (hgprtase) affinity chromatography. the specific activities of the affinity-purified aprtase and hgprtase fractions were 326-fold and 1341-fold greater than those in the 40-80% ammonium sulfa ...19892704389
structure of the phosphosaccharide-inositol core of the leishmania donovani lipophosphoglycan.the phosphosaccharide-inositol core of the lipophosphoglycan of leishmania donovani was generated by treatment of the glycoconjugate with mild acid and digestion with phosphatidylinositol-specific phospholipase c. the core was purified and examined by one- and two-dimensional 1h-1h nmr and by methylation analysis. from the results, the carbohydrate core was elucidated as a phosphosaccharide attached to the inositol residue of the lyso-alkylphosphatidylinositol anchor of lipophosphoglycan as foll ...19892708338
suppression of macrophage lysosomal enzymes after leishmania donovani infection.in order to have an insight into the role of host lysosomal enzymes in the intracellular survival of leishmania parasites, the activities of beta-galactosidase, alpha-mannosidase, and n-acetyl-beta-d-glucosaminidase were studied in peritoneal macrophages of hamsters infected with l. donovani. there was a significant decrease of all three lysosomal enzymes after infection. heat-killed or formalin-treated parasites failed to inhibit the enzymes, instead a slight stimulation was observed. purified ...19892713150
use of whole parasite for quick screening of hybridomas against leishmania donovani. 19892714818
[visceral leishmaniasis in infants without bioptic demonstration of the parasite. presentation of 3 cases].the authors describe three infants with visceral leishmaniasis in whom bioptic research (in marrow, spleen and liver) has not demonstrated presence of leishmania. they remark this unusual aspect of visceral leishmaniasis in infant and debate the epidemiological, diagnostic, and therapeutic aspects of these cases.19892717490
potent antibacterial fluoroquinolones with marked activity against leishmania donovani in vivo. 19892726722
epidemiology of visceral leishmaniasis in colombia.epidemiologic studies were conducted during the period 1986-1988 in a small rural community in colombia (el callejon) where visceral leishmaniasis is highly endemic. in this community of 185 people, 14 cases of infantile visceral leishmaniasis were diagnosed in the 9 years 1981-1988. leishmanin skin testing of a sample of the human residents showed that prevalence of leishmania chagasi infection increased with age; overall, 51.2% of the subjects had a positive reaction. a canine surveillance pro ...19892729506
characterization of integral membrane proteins of leishmania major by triton x-114 fractionation and analysis of vaccination effects in mice.the total integral membrane proteins of promastigotes of leishmania major were extracted by using the triton x-114 phase separation technique and were characterized by immunoprecipitation, western blotting (immunoblotting), and lectin chromatography. of the 40 or more proteins which partitioned into the detergent phase, only about 10 proteins could be surface radioiodinated on live promastigotes, suggesting their surface orientation. the abundance of the gp58-63 antigen varied markedly between t ...19892731987
regulation of intracellular calcium in promastigotes of the human protozoan parasite leishmania donovani.by using the fluorescent ca2+ indicator fura 2, we show that the concentration of free calcium in the cytoplasm of leishmania donovani promastigotes is maintained at very low levels (73.5 +/- 10-94 +/- 8 nm at a [ca2+]i range of 0-1 mm). the maintenance of low [ca2+]i is energy-dependent as it is disrupted by kcn, h+-atpase inhibitors, and ionophores. kcn, nigericin, and n,n'-dicyclohexylcarbodiimide increase cytosolic free calcium by mobilizing calcium from intracellular pools. monensin and oli ...19892732230
identification of major antigens of leishmania donovani using kala azar sera.the study was conducted with the prime objective of isolating an antigen from the crude preparation of whole promastigotes (leishmania donovani) with a view to future exploitation in serodiagnosis and production of monoclonal antibodies. soluble antigen, prepared from promastigotes isolated from actively growing cultures, was fractionated by gel filtration chromatography over a column of sephadex g200. three peaks of proteins could be recovered. the antigenic reactivity of different fractions wa ...19892733636
[leishmania infantum mon-98, a new zymodem isolated from human visceral leishmaniasis in egypt (el agamy)]. 19892735704
protective effect of l. donovani antigens using glucan as an adjuvant.golden hamsters were immunized with various antigen fractions of leishmania donovani promastigotes. beta 1,3-glucan was used as an adjuvant in these vaccination experiments. the results indicate that immunization of animals with the microsomal fraction (subcellular fraction iii) in combination with glucan confers considerable immune protection against l. donovani infection. the immune protection was confirmed by correspondingly lower parasite burden in the livers and spleens of test animals comp ...19892737802
expression of the major surface glycoprotein of leishmania donovani chagasi in virulent and attenuated promastigotes.using both hamster and mouse models of infection, we documented that the virulence of leishmania donovani chagasi promastigotes decreases over time, when parasites are maintained in long term culture after isolation from an infected animal. concomitant with this loss of virulence is a marked decrease in amount of the major promastigote surface glycoprotein, gp63, present in promastigotes. the latter was shown by a decrease in binding of polyclonal anti-gp63 serum to attenuated (cultivated long t ...19892738406
visceral leishmaniasis in patients infected with human immunodeficiency virus (hiv).in an 8-month period nine patients with human immunodeficiency virus (hiv) infection were diagnosed as having visceral leishmaniasis; all diagnoses were based on cultures (eight from bone marrow and one from the skin). visceral leishmaniasis developed before full-blown acquired immunodeficiency syndrome (aids) in seven patients and at the same time as or after aids in the other two patients. three patients had a history of leishmaniasis. clinical manifestations and laboratory findings were atypi ...19892742248
association of visceral leishmaniasis and human immunodeficiency virus infections. 19892760511
effects of thiastearic acids on growth and on dihydrosterculic acid and other phospholipid fatty acyl groups of leishmania promastigotes.thiastearic acid positional isomers (8, 9, 10, 11) were examined for their ability to inhibit population growth and the biosynthesis of a phosphatidylethanolamine cyclopropane fatty acyl group, cis-9,10-methyleneoctadecanoic acid (dihydrosterculic acid), by promastigotes of leishmania species. thiastearic acids are candidate chemotherapeutic agents, since cyclopropane fatty acids are not formed by vertebrate cells. 8- and 10-thiastearic acids strongly inhibited the growth of strains containing t ...19892761573
experimental visceral leishmaniasis in the opossum.adult wild-trapped opossums were infected with leishmania donovani (khartoum strain, wr 378) and evaluated as an animal model of visceral leishmaniasis. all infected opossums died within 32 days. loss of body fat, hepatomegaly, and petechiae of skin and abdominal musculature were seen at necropsy. microscopically, numerous amastigote-laden macrophages were seen in histologic sections of liver, spleen, and lymph nodes; fewer parasite-laden macrophages were in the bronchial-associated lymphoid tis ...19892763421
chromosome size and number polymorphisms in leishmania infantum suggest amplification/deletion and possible genetic exchange.we have studied the molecular karyotypes of 21 strains and 14 clones of leishmania infantum using pulsed field gel electrophoresis (pfge). we detected a high degree of polymorphism within this species, with 'strain-specific' patterns for most isolates, even within a restricted endemic area. variations relate to both the size of chromosomes (270-2600 kb) and their number, which can vary from 24 to 31 between closely related isolates. this polymorphism does not correlate with isoenzyme analysis. s ...19892770788
effect of heat-shock & nutritional stress on the expression of a neutral thiol protease in leishmania donovani promastigotes.the soluble intracellular protease was partially purified from l. donovani promastigotes. the activity of this enzyme increased with increase in temperature from 25 degrees c to 37 degrees c and was active optimally at 70 degrees c. this protease activity appeared to be decreased due to heat-shock of the promastigotes for 4 h at 37 degrees c and increased due to nutrient starvation. inhibition of the protease by p-chloromercuribenzoate and iodoacetamide suggested that this enzyme could be a thio ...19892777346
killing of leishmania donovani by activated liver macrophages from resistant and susceptible strains of mice.leishmania donovani is an obligate intracellular protozoan parasite of macrophages; liver macrophages are, however, the only population of cells which express the resistant lsh gene phenotype when these cells are infected in vitro. it was of interest to study in vitro the action of con a-stimulated spleen cell lymphokines (lk) to protect or to cure liver macrophages from infection by l. donovani. liver and peritoneal macrophages (pec) from resistant (c57l/j) and susceptible (c57bl/6j) mice were ...19892777460
vaccination trial against canine visceral leishmaniasis. phocean veterinary study group on visceral leishmaniasis.in a double-blind study 393 seronegative dogs, residing in a holoendemic area for leishmania donovani infantum infection, were randomly assigned to an immunization with a partly purified l.d. infantum-derived preparation, or received adjuvant only. during the first year of the study period the rate of infection was significantly higher in the vaccinated group than in the control one (p less than 0.05), but this difference disappeared during the second year (p = 0.44). since a similar immunizatio ...19892780090
selective delivery of drugs to macrophages through a highly specific receptor. an efficient chemotherapeutic approach against leishmaniasis.methotrexate (mtx) conjugated with maleylated bovine serum albumin (mtx-mbsa) was taken up and degraded by cultured hamster peritoneal macrophages through the polyanion binding site for acetylated low density lipoprotein. mtx-mbsa also eliminated intracellular amastigotes of leishmania donovani in cultured hamster peritoneal macrophages about three times more efficiently than free mtx. the antileishmanial effect of mtx-mbsa on parasitized macrophages was blocked by mbsa, lysosomal inhibitors (ch ...19892783154
autoantibody production by patients infected with leishmania.sera from 29 patients with visceral leishmaniasis and 14 patients with cutaneous leishmaniasis were tested against a panel of nine nuclear antigens employing an enzyme-linked immunosorbent assay (elisa). anti- sm, rnp, ss-a and ss-b antibodies were present in high titres in 83, 86, 36 and 73 per cent of the patients with visceral leishmaniasis and in 7, 14, 25 and 25 per cent of the patients with cutaneous leishmaniasis. one serum from a patient with visceral leishmaniasis which reacted strongly ...19892788044
characterization of protective t cells in the acquired response to leishmania donovani in genetically determined cure (h-2b) and noncure (h-2d) mouse strains.the response to reinfection with ethiopian leishmania donovani was evaluated in genetically determined noncure (h-2d) b10.d2 mice that are able to resolve infection due to sublethal irradiation pretreatment after inoculation with a low parasite dose and in c57bl/10 mice that demonstrate the genetically determined cure (h-2b) response to l. donovani. it was found that after resolution of primary infection, c57bl/10 (cure) mice and sublethally irradiated b10.d2 (noncure) mice were resistant to rec ...19892788140
susceptibility of 3h-thymidine-prelabelled leishmania donovani amastigotes and promastigotes to the cytotoxic activity of peritoneal, splenic and liver macrophages.c57bl/6 macrophage populations from spleen and liver, the main organs for the manifestation of visceral leishmaniasis, were investigated for their ability to perform spontaneous phagocytosis-associated killing of 3h-thymidine (3h-tdr)-prelabelled l. donovani amastigotes and promastigotes. the results showed that organ macrophages from spleen and liver killed l. donovani amastigotes and promastigotes spontaneously with high efficiency. this consistent finding was first detectable at 2-3 h, and th ...19892793202
[simultaneous presence in dogs of 2 zymodemes of the leishmania infantum complex].the concomitant presence of two zymodemes of the leishmania infantum complex. mon-1 and mon-77, is reported in a dog with diffuse leishmaniasis. the zymodemes were present in both the skin and lymph nodes. possible explanations for the presence of the two zymodemes are discussed.19892817695
a tandem pair of leishmania donovani cation transporting atpase genes encode isoforms that are differentially expressed.the second gene (atpase 1b) of a tandem pair of cation transporting atpases from leishmania donovani was cloned and sequenced. the sequence of this gene was very similar to its upstream neighbor (atpase 1a). both genes contained a 2922 base open reading frame capable of encoding a protein of 974 amino acids. the genes differed at 34 nucleotide base positions, predicting 20 amino acid differences between the two peptides. these changes were clustered at the carboxy terminus with 15 changes occurr ...19892469011
hybrid molecules: growth inhibition of leishmania donovani promastigotes by thiosemicarbazones of 3-carboxy-beta-carbolines.the thiosemicarbazones of beta-carboline-3-carboxaldehyde (compound 2) and 3-acetyl-beta-carboline (compound 3) were found to effectively inhibit the in vitro growth of the promastigote form of leishmania donovani, 50% inhibition being obtained at concentrations of 5.0 and 2.5 microm, respectively, while irreversible growth inhibition was achieved at 40 (compound 2) and 17.5 microm (compound 3). the thiosemicarbazone of pyridine-2-carboxyaldehyde (compound 4) was considerably less active while b ...19892470903
the immunochemical structure and surface arrangement of leishmania donovani lipophosphoglycan determined using monoclonal antibodies.using intact leishmania donovani promastigotes or purified l. donovani lipophosphoglycan (lpg) as immunogens, we have derived four lpg-specific monoclonal antibodies (mabs). two of these mabs recognize an epitope consisting of the repeating phosphorylated galactose beta-1,4-mannose disaccharide portion of the molecule and cross-reacted with lpg from leishmania major. these mabs bound to the surface of living promastigotes of both species. the two other mabs bound to the phosphosaccharide core st ...19892475775
identification of antigens recognized by t cells in human leishmaniasis: analysis of t-cell clones by immunoblotting.immunity in human leishmaniasis is mediated by sensitized t lymphocytes; however, the antigens involved in eliciting this immunity have not been defined. we describe the generation of human t-lymphocyte clones derived from two patients with healed leishmaniasis. by use of one- and two-dimensional cellular immunoblotting techniques, we directly identified the parasite antigens recognized by these clones. to our knowledge, these are the first leishmanial antigens identified to which cd4+, gamma in ...19892476395
purine deoxynucleoside salvage in giardia lamblia.giardia lamblia is dependent on the salvage of preformed purines and pyrimidines, including deoxythymidine. dependence on deoxynucleoside salvage is extremely unusual among eucaryotic cells (moore, e. c., and hurlbert, r. b. (1985) pharmacol & ther. 27, 167-196). the present study investigates the possibility that giardia lacks ribonucleotide reductase and depends entirely on deoxynucleoside salvage. a ribonucleotide reductase inhibitor, hydroxyurea, at concentrations up to 2 mm had no effect on ...19892480350
a rapid staining technique for leishmania parasites in splenic aspirate smears.a quick and suitable method for staining leishmania donovani and other blood protozoa is described. the method, which could have wide applications, is a modification of field's staining technique as used for malaria parasites. it uses the same stains in a different order. the method has been tried on smears containing malaria and trypanosomes, and the results were good. it is very cheap and requires no special apparatus or training.19892481429
detection of antigen specific circulating immune complexes in indian kala-azar.the sera of active and treated cases of kala-azar were tested for circulating immune complexes (cic) by antigen-specific enzyme linked immunosorbent assay (elisa). all (100%) of proved cases had elevated cic; 64.3% of clinically diagnosed cases and 58.8% of treated cases were also positive for cic. a fall in the level of cic was observed after treatment. detection of antigen-specific cic may be useful in monitoring the therapeutic effect and recovery.19892482707
leishmaniasis in bolivia. vii. infection of sentinel porcupines (coendou prehensilis, l.) by leishmania (le.) chagasi. 19892487453
role of tryptophan degradation in respiratory burst-independent antimicrobial activity of gamma interferon-stimulated human macrophages.to determine whether extracellular tryptophan degradation represents an oxygen-independent antimicrobial mechanism, we examined the effect of exogenous tryptophan on the intracellular antimicrobial activity of gamma interferon (ifn-gamma)-stimulated human macrophages. ifn-gamma readily induced normal monocyte-derived macrophages (mdm) to express indoleamine 2,3-dioxygenase (ido) activity and stimulated mdm, alveolar macrophages, and oxidatively deficient chronic granulomatous disease mdm to degr ...19892492973
[an immunologic method of producing antigens for the treatment and prevention of leishmaniasis].antigens isolated from lysates of l. infantum promastigotes by electroelution from polyacrylamide gels and by gel filtration, have already been proven to induce anti-leishmania protective immunity in balb/c mice when injected subcutaneously. at the present time, five preparations including either leishmania antigens or anti-idiotypic reagents as vaccines can be considered as candidates for immunoprophylaxis in natural hosts of leishmania parasites. we present a new method for producing leishmani ...19892493318
putrescine transport system in leishmania infantum promastigotes.a transport system for putrescine in leishmania infantum (= l. donovani infantum) promastigotes has been identified and characterized by measuring the uptake of radioactively labelled putrescine. putrescine uptake was time- and temperature-dependent without any accumulation taking place at 0 degrees c. uptake of putrescine was maximal at ph values near neutrality. putrescine uptake showed an apparent km = 1.08 +/- 0.12 microm and a vmax = 1.74 + 0.62 pmol min-1 (10(6) cells)-1. the effect of met ...19892503722
enhancement of macrophage il-1 production by leishmania major infection in vitro and its inhibition by ifn-gamma.peritoneal cells from highly susceptible balb/c mice were infected with leishmania major and cultured for various times in vitro. the culture supernatants contained significant levels of il-1 which were consistently higher than those in the cell cultures stimulated with an optimal concentration of lps. this finding extends to a macrophage cell line, p388d1, and peritoneal exudate cells stimulated with starch in vivo. however, the level of il-1 produced was significantly reduced when the cells we ...19892506273
mouse interferon-gamma in liposomes: pharmacokinetics, organ-distribution, and activation of spleen and liver macrophages in vivo.recombinant mouse interferon-gamma (ifn-gamma) was encapsulated into multilamellar vesicles and the proportion of encapsulated ifn-gamma determined by biological activity was 19%. the distribution of 125i-labeled ifn-gamma liposomes in c57bl/6 mice was analyzed. after an initial enrichment of liposomes in lung, more than 60% of total 125i-labeled ifn-gamma was accumulated in spleen and liver. furthermore, it was observed if the encapsulation of ifn-gamma in liposomes prevented the rapid decay of ...19892507661
antileishmanial effect of free and encapsulated sinefungin against leishmania donovani infections in balb/c mice.sinefungin, a c-nucleoside antibiotic, displays a high antiparasitic action. the effect of free and microencapsulated sinefungin was compared on balb/c mice infected with leishmania donovani; the encapsulated form proved more effective by one order of magnitude.19892508995
the oxidative response of rabbit peritoneal neutrophils to leishmanias and other trypanosomatids.luminometry has been used to measure the respiratory burst of rabbit peritoneal neutrophils that is elicited by different forms and species of leishmania and herpetomonas. mid-log phase and metacyclic promastigotes of l. major evoked large responses; that due to metacyclics was lower and slower, but they also bound in smaller numbers than mid-log phase cells. promastigotes of l. mexicana mexicana also stimulated a large respiratory burst whereas amastigotes elicited little or none. leishmania do ...19892509389
il-4 inhibits h2o2 production and antileishmanial capacity of human cultured monocytes mediated by ifn-gamma.the effect of il-4 on the ifn-gamma-induced state of activation of cultured human monocytes was investigated with regard to their ability to produce hydrogen peroxide and their antileishmanial capacity towards the intracellular parasite leishmania donovani. il-4 was found to inhibit the ifn-gamma-dependent hydrogen peroxide production of monocytes. treatment of monocytes with ifn-gamma (200 to 600 u/ml) for 48 h increased the hydrogen peroxide production fourfold above background. coincubation o ...19892509562
experimental visceral leishmaniasis: role of endogenous ifn-gamma in host defense and tissue granulomatous response.the capacity of balb/c mice to acquire resistance to and eliminate intracellular visceral leishmania donovani is t cell dependent, associated with a granulomatous tissue reaction, and correlates with the ability to secrete the macrophage-activating lymphokine, ifn-gamma. these responses appear by 4 wk after infection and are fully established by 8 wk. to examine the role of endogenous ifn-gamma, balb/c mice were injected with anti-ifn-gamma mab before and for 8 wk after infection. at 4 wk, mab t ...19892512353
c-fos and tumor necrosis factor gene expression in leishmania donovani-infected macrophages.leishmania donovani is an obligate intracellular protozoan which resides in macrophages and impairs a number of macrophage functions. we have undertaken to study this host cell-parasite interaction by examining the ability of l. donovani to impair the transmission of information from the cell surface to the nucleus and thus influence normal gene expression. we demonstrate that, in response to lipopolysaccharide, expression of both the c-fos and tumor necrosis factor genes was impaired in l. dono ...19892513483
the feasibility of discrimination between leishmania and endotrypanum using total parasite dna probes. 19892514470
further characterization of chinese leishmania isolates by isoenzyme electrophoresis.ten chinese leishmania isolates from different endemic areas and hosts are characterized by isoenzyme electrophoresis for 9 enzymes. seven were isolated from visceral leishmaniasis patients, one from an infected dog, one from a sandfly and one from a naturally infected racoon dog. eight of the 10 isolates were indistinguishable in isoenzyme profile from the l infantum reference strain. the isoenzyme profiles of the remaining two isolates (from kala azar patients in xinjiang) could not be charact ...19892517080
in vivo effect of eflornithine (dfmo) and some related compounds on leishmania infantum preliminary communication.an in vivo method was used to test the effect of eflornithine (dfmo) and five related compounds on leishmania infantum amastigotes. treatment with 100 mg/kg sc for 5 days of leishmania infected balb/c mice yielded a parasite inhibition ranging from 56% (compound 2, "reverse arginine") to 85% (eflornithine), these values being lower than that obtained with the reference compound glucantime (93%). in long-term treatment (40 days) the two selected compounds, eflornithine and 3 ("reverse homoarginin ...19892517472
antigen-specific immunosuppression in visceral leishmaniasis is cell mediated.visceral leishmaniasis is associated with an antigen-specific immunosuppression during the acute disease. patients become responsive to leishmania antigen in both in vivo and in vitro assays after successful antimony therapy. the cell type involved in the suppression of lymphocyte reactivity to leishmania antigen was studied by selective depletion of mononuclear cell (mnc) populations and in co-cultivation experiments. adherent cells were depleted on plastic and by passage on nylon wool columns. ...19892522103
inhibitory effects on protein kinase c activity by lipophosphoglycan fragments and glycosylphosphatidylinositol antigens of the protozoan parasite leishmania.fragments of the lipophosphoglycan of leishmania donovani were generated by phospholipase c digestion and mild acid hydrolysis. the fragments were purified and examined for inhibitory activity on protein kinase c isolated from rat brains. on a molar basis, the 1-o-alkylglycerol portion of lpg exhibited the most inhibitory activity, whereas the carbohydrate domain was not as effective. in addition, several glycolipid antigens from l. major, which contain short carbohydrate chains attached to phos ...19892524191
the effect of cyclosporin a in murine visceral leishmaniasis.leishmania donovani is an obligate intracellular protozoan parasite of macrophages whose control is effected by cellular mechanism. in order to determine the role of t-helper cells and their soluble mediators in the control of the infection, the effects of cyclosporin a (csa) were studied in strains of mice (c57l/j and c57bl/6j) known to be resistant and susceptible. mice treated with csa (200 mg/kg) exhibited as early as day 15 a significant increase in the level of their infection. the number ...19892525802
comparison of t-cell responses in self-limiting versus progressive visceral leishmania donovani infections in golden hamsters.leishmania donovani infection in golden hamsters was studied as a model for human kala-azar. after intradermal inoculation of l. donovani amastigotes, hamsters developed positive skin reactions (delayed-type hypersensitivity [dth]) to parasite antigens and lymphoid cells from these hamsters proliferated to parasite antigens in vitro and transferred dth reactivity to normal recipients. in contrast, hamsters infected by the intracardial route developed progressive visceral infections and failed to ...19892528507
[visceral leishmaniasis in ordubad district, nakhichevan assr].visceral leishmaniasis (vl) focus in the ordubad district of the nakhichevan assr has become active for the last years. complex study of the focus, performed in 1985-1987, allowed to establish the following: vl causative agent, circulating in the ordubad district belongs to the leishmania infantum species. it was identified by isoenzymatic analysis (for 12 enzymes) and the adler serological test. disease cases prevailed in the upper part of the town of ordubad and were confined to a small area ( ...19892528672
importance of lymphokines in the control of multiplication and dispersion of leishmania donovani within liver macrophages of resistant and susceptible mice.leishmania donovani is an obligate intracellular parasite of mammalian macrophages. the immunosuppressant cyclosporin a (csa), which inhibits the production of interleukin (il)-1, il-2, and interferon-gamma, increased infections 3-fold without affecting expression of the lsh gene. the objective of this study was to determine how activation of macrophages by lymphokines affects the multiplication and propagation of the parasite within liver macrophages. susceptible c57bl/6j and resistant c57l/j m ...19892529362
study of circulating immune complexes during the evolution of visceral mediterranean leishmaniasis.in the present study, sera of 56 children suffering from visceral mediterranean leishmaniasis were analysed. the incidence of circulating immune complexes (cic) by elisa technique using the conglutinin binding assay was 39% before treatment, 28% after the first treatment, and nil at the end of the second one. the c4 levels remain low even after treatment. the anti-leishmania antibodies (aal) account for 95% of the cases before treatment and 84% after treatment. the rheumatoid factor (fr) also re ...19892532497
[serologic examination of the population of cleaned-up foci of visceral leishmaniasis in the territory of the uzbek ssr].retrospective screening of population was carried out in the uzbek ssr in 3 physiographic regions, which formerly represented active epidemic foci of visceral leishmaniasis. seroepidemiologic examination of 8652 persons showed satisfactory results concerning the disease at present. despite low seropositive level of healthy population in general (0.38%), a correlation was detected between the number of positive indirect immunofluorescence results and the incidence rate of visceral leishmaniasis i ...19892534148
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