| 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 ... | 1989 | 2685025 |
| 27th forum in immunology. the macrophage resistance gene lsh/ity/bcg. | | 1989 | 2696046 |
| the macrophage resistance gene lsh/ity/bcg. | | 1989 | 2696047 |
| a comparison of genetic linkage maps surrounding the lsh/ity/bcg disease resistance locus. | | 1989 | 2696048 |
| a reverse genetics approach to bcg/ity/lsh gene cloning. | | 1989 | 2696049 |
| role of lsh in regulating macrophage priming/activation. | | 1989 | 2696053 |
| lsh, antigen presentation and the development of cmi. | | 1989 | 2696054 |
| ity and after. | | 1989 | 2696055 |
| 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 ... | 1989 | 2696860 |
| 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 ... | 1989 | 2704389 |
| 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 ... | 1989 | 2708338 |
| 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 ... | 1989 | 2713150 |
| use of whole parasite for quick screening of hybridomas against leishmania donovani. | | 1989 | 2714818 |
| [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. | 1989 | 2717490 |
| potent antibacterial fluoroquinolones with marked activity against leishmania donovani in vivo. | | 1989 | 2726722 |
| 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 ... | 1989 | 2729506 |
| 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 ... | 1989 | 2731987 |
| 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 ... | 1989 | 2732230 |
| 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 ... | 1989 | 2733636 |
| [leishmania infantum mon-98, a new zymodem isolated from human visceral leishmaniasis in egypt (el agamy)]. | | 1989 | 2735704 |
| 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 ... | 1989 | 2737802 |
| 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 ... | 1989 | 2738406 |
| 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 ... | 1989 | 2742248 |
| association of visceral leishmaniasis and human immunodeficiency virus infections. | | 1989 | 2760511 |
| 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 ... | 1989 | 2761573 |
| 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 ... | 1989 | 2763421 |
| 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 ... | 1989 | 2770788 |
| 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 ... | 1989 | 2777346 |
| 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 ... | 1989 | 2777460 |
| 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 ... | 1989 | 2780090 |
| 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 ... | 1989 | 2783154 |
| 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 ... | 1989 | 2788044 |
| 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 ... | 1989 | 2788140 |
| 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 ... | 1989 | 2793202 |
| [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. | 1989 | 2817695 |
| molecular karyotype of five species of leishmania and analysis of gene locations and chromosomal rearrangements. | the molecular karyotypes of five species of leishmania were studied by pulsed field gradient gel electrophoresis (pfgge) of chromosome-sized dna bands. each species exhibits a unique pattern of 22-28 bands in the size range approximately 200-2200 kb whereas strains of one species exhibit similar karyotypes. analysis of the behaviour of kinetoplast dna during pfgge showed that minicircle dna remains confined to the gel slot but a proportion of the maxicircle dna fractionates as a low molecular we ... | 1987 | 2827021 |
| structure and expression of a tandem gene pair in leishmania donovani that encodes a protein structurally homologous to eucaryotic cation-transporting atpases. | an oligonucleotide probe was used to clone a cation-transporting atpase gene from the genome of leishmania donovani. the nucleotide sequence of the gene contained a 2,922-base-pair open reading frame that was predicted to encode a 107,406-dalton protein composed of 974 amino acids. the predicted l. donovani protein contained all the structural and functional domains expected to be present in a cation-transporting atpase of the aspartyl phosphate class. the nucleotide sequence encoding the atpase ... | 1987 | 2828921 |
| decatenation of kinetoplast dna by an atp-dependent dna topoisomerase from the kinetoplast hemoflagellate leishmania donovani. | an enzyme from leishmania donovani that decatenates kinetoplast dna networks into covalently closed monomeric circles has been isolated and characterized. the enzyme also relaxes supercoiled plasmid pbr322. the decatenation and relaxation reactions both require atp and mg2+. in both reactions the formation of topological isomers of unique linking numbers suggests that the enzyme is a type ii dna topoisomerase. both the relaxation and decatenating activities are inhibited by novobiocin at a very ... | 1987 | 2828947 |
| a case of laboratory acquired leishmania donovani infection; evidence for primary lymphatic dissemination. | we report the case of a laboratory worker who received close medical follow-up after accidently inoculating her hand with a needle containing a humera strain of leishmania donovani amastigotes. she developed a leishmanoma and histologic evidence of local lymphatic dissemination before being treated. the spectrum of disease caused by l. donovani is discussed. | 1987 | 2832980 |
| a tissue culture system for the growth of several species of leishmania: growth kinetics and drug sensitivities. | we have developed a simple in vitro method of infecting a continuous human macrophage cell line (u937) with promastigotes of several species of leishmania. these include l. braziliensis braziliensis, l. b. panamensis, l. donovani, l. mexicana mexicana, l. m. pifanoi, l. tropica, and l. major. the growth kinetics of these species are presented as well as drug sensitivity data. the u937 cell system can be used to determine drug efficacy and eliminates the need to use amastigotes from animal tissue ... | 1988 | 2833127 |
| immunochemotherapy for intracellular leishmania donovani infection: gamma interferon plus pentavalent antimony. | to determine if the macrophage-activating t cell lymphokine gamma interferon (ifn-gamma) can enhance the effect of conventional chemotherapy against intracellular leishmania donovani, we treated human macrophages in vitro with both recombinant (r) ifn-gamma and sodium stibogluconate (pentostam). after pretreatment with a nonactivating dose of rifn-gamma (10 u/ml), ineffective concentrations of pentostam (1 and 5 micrograms/ml) were converted to leishmanistatic concentrations, and a leishmanistat ... | 1988 | 2834469 |
| mode of action of pentavalent antimonials: specific inhibition of type i dna topoisomerase of leishmania donovani. | sodium stibogluconate and ureastibamine, two potent antileishmanial drugs specifically inhibit the relaxation of supercoiled plasmid pbr322 catalyzed by dna topoisomerase i of leishmania donovani. dose dependent inhibition suggests that the drugs interact with the enzyme rather than the dna. the inhibition reported here concerning a type i dna topoisomerase demonstrates at least one possible mode of action of these antileishmanial drugs. | 1988 | 2835038 |
| reaction kinetics and inhibition of adenosine kinase from leishmania donovani. | the reaction kinetics and the inhibitor specificity of adenosine kinase (atp:adenosine 5'-phosphotransferase, ec 2.7.1.20) from leishmania donovani, have been analysed using homogeneous preparation of the enzyme. the reaction proceeds with equimolar stoichiometry of each reactant. double reciprocal plots of initial velocity studies in the absence of products yielded intersecting lines for both adenosine and mg2+-atp. amp is a competitive inhibitor of the enzyme with respect to adenosine and nonc ... | 1988 | 2838751 |
| an experimental model system for leishmaniasis. an ultrastructural study on cultured macrophages exposed to leishmania parasites and sodium stibogluconate. | to facilitate studies on the effect of chemotherapeutic agents on the host-parasite interaction in leishmaniasis, we have developed an experimental model for infecting mouse peritoneal macrophages in culture with recently-isolated leishmania donovani promastigotes. as the drug action is often dependent on concentration, the distribution of sodium stibogluconate, which is the commonly used drug for treatment of leishmaniasis, was studied in various parts of the macrophages by energy dispersive x- ... | 1988 | 2841954 |
| the synergistic action of pyrazolopyrimidines and pentavalent antimony against leishmania donovani and l. braziliensis. | pyrazolopyrimidines, particularly allopurinol, allopurinol riboside, and other purine analogues, show promise as experimental therapeutic compounds for the treatment of leishmaniasis. the combination of these agents with pentostam may produce an improved therapeutic effect. we report here on strong synergistic activity between pyrazolopyrimidines and pentavalent antimonials in a human macrophage tissue culture system infected with leishmania donovani and l. braziliensis. | 1988 | 2845824 |
| antibody kinetics in kala-azar in response to treatment. | | 1987 | 2845873 |
| effects of antimycotic azoles on growth and sterol biosynthesis of leishmania promastigotes. | promastigotes of 36 world health organization reference (and other) strains of 6 species and 10 subspecies of leishmania were cultured in the presence of 3 antimycotic azole drugs (ketoconazole, itraconazole, fluconazole) and their population growth determined. a representative of each subspecies was also analyzed for its sterol composition. for all strains the order of azole drug activity with respect to both growth and sterol biosynthesis inhibition was itraconazole greater than or equal to ke ... | 1988 | 2847043 |
| [visceral leishmaniasis (kala-azar) in acquired immunodeficiency syndrome (aids)]. | a 32-year-old homosexual with aids, who until 1985 was a frequent traveller to south america and mediterranean countries, had recurrent bouts of fever, splenomegaly, arthralgias as well as granulocytopenia and anaemia. liver and bone-marrow punctures were performed to exclude malignant lymphoma and (or) a mycobacterial infection. both biopsies revealed leishmania donovani. during administration of sodium stibogluconate (pentostam) the fever disappeared for a time and there was clinical improveme ... | 1988 | 2848675 |
| [analysis of the sequence homologies in k-dna of different leishmania isolates by dna hybridization technique]. | | 1988 | 2855320 |
| [identification of leishmania by dot blot hybridization with photobiotin labelled k-dna]. | | 1988 | 2855321 |
| physical characterisation of kinetoplast dna of an indian strain of leishmania donovani, the causative agent of visceral leishmaniasis. | | 1988 | 2855628 |
| limited activity of bacterial dna topoisomerase ii inhibitors against leishmania donovani and trypanosoma cruzi amastigotes in vitro. | | 1988 | 2855767 |
| the activity of nitrofurazone and furazolidone against leishmania donovani, l. major and l. enriettii in vitro and in vivo. | furazolidone and nitrofurazone showed in vitro activity against amastigotes of leishmania donovani, l. enriettii and l. major in macrophages, at concentrations which were also toxic to the macrophages. a low grade of activity was observed against l. donovani infections in balb/c mice by furazolidone but not with nitrofurazone. nitrofurazone, in two concentrations, was not active when applied to the lesions of cutaneous leishmaniasis due to l. enriettii (guinea-pig infection) or l. major strain p ... | 1988 | 2855778 |
| primary agent for leishmaniasis. | | 1988 | 2856321 |
| leishmania donovani: an opportunistic microbe associated with progressive disease in three immunocompromised patients. | three cases are described showing that leishmania donovani can cause progressive disease in immunocompromised hosts. the first patient was receiving corticosteroid therapy for ulcerative colitis and the second corticosteroids and cyclophosphamide for proliferative glomerulonephritis; in the third patient, leishmaniasis occurred after a long episode of hepatosplenic schistosomiasis and salmonella bacteraemia which was treated with chloramphenicol. in two cases, the patients had moved away from ar ... | 1986 | 2869348 |
| visceral leishmaniasis as an opportunistic infection. | | 1986 | 2871358 |
| non-ionic surfactant vesicles, niosomes, as a delivery system for the anti-leishmanial drug, sodium stibogluconate. | liver and serum concentrations of antimony in the mouse have been determined after administration of sodium stibogluconate in the free, liposomal and niosomal form. high liver and low serum values were attained by the use of both vesicular formulations. niosomal sodium stibogluconate was shown to be more active than free drug against experimental murine visceral leishmaniasis, an effect apparently dependent on maintaining high drug levels in the infected reticuloendothelial system. | 1986 | 2875149 |
| immunization of hamsters with tlck-killed parasites induces protection against leishmania infection. | hamsters immunized with n-p-tosyl-l-lysine-chloromethyl ketone tlck-treated l. brasiliensis brasiliensis (lb) from culture, infected with lb amastigotes presented: a gradual increase in t and b cell responsiveness to mitogens by lymph node lymphocytes, and an increased response to concanavalin a with no changes for dextran sulphate and pokeweed mitogen in splenocytes. absence of parasites in lymph nodes after 6 weeks post-infection and a nodule 4 times smaller than that of infected control anima ... | 1986 | 2877549 |
| safety and efficacy of high-dose sodium stibogluconate therapy of american cutaneous leishmaniasis. | 40 patients with american cutaneous leishmaniasis caused primarily by leishmania braziliensis panamensis were treated with sodium stibogluconate in a double-blind, randomised controlled trial. nine weeks after starting treatment, all 19 patients treated with 20 mg sb/kg per day for twenty days were cured but 5 of 21 patients treated with 10 mg sb/kg per day for twenty days had persistent active disease (p less than 0.05). both treatment regimens were well tolerated and they were associated with ... | 1987 | 2885505 |
| inhibition of monocyte oxidative responses by bordetella pertussis adenylate cyclase toxin. | bordetella pertussis and the other bordetella species produce a novel adenylate cyclase toxin which enters target cells to catalyze the production of supraphysiologic levels of intracellular cyclic adenosine monophosphate (camp). in these studies, dialyzed extracts from b. pertussis containing the adenylate cyclase toxin, a partially purified preparation of adenylate cyclase toxin, and extracts from transposon tn5 mutants of b. pertussis lacking the adenylate cyclase toxin, were used to assess t ... | 1987 | 2888823 |
| aspartate transcarbamylase from leishmania donovani. a discrete, nonregulatory enzyme as a potential chemotherapeutic site. | leishmania donovani is a protozoal pathogen that belongs to the kinetoplastida order. unlike in other eucaryotic systems, the first three enzymes of the de novo pyrimidine biosynthetic pathway are not components of a multifunctional protein system. the three enzyme activities in the crude extract were separated on a sephacryl s-200 column. aspartate carbamoyltransferase (ec 2.1.3.2) has been purified to apparent homogeneity. the enzyme has an approximate molecular weight of 135,000 and seems to ... | 1988 | 2891701 |
| biodegradable microspheres: polyacryl starch microparticles as a delivery system for the antileishmanial drug, sodium stibogluconate. | liver parasite burdens of leishmania donovani in the mouse have been determined after treatment with intravenous administration of sodium stibogluconate in the free or carrier form. the carrier form, in which the drug was covalently bound to polyacryl starch microparticles, was up to 100x more effective than the free form in this murine model of visceral leishmaniasis. empty microparticles had no effect on liver parasite burdens and the enhanced in-vivo antileishmanial activity of the carrier fo ... | 1987 | 2891821 |
| the promastigote surface protease of leishmania donovani infantum in the midgut of phlebotomus perniciosus. | | 1987 | 2892377 |
| comparative infectivity of a kenyan strain of leishmania donovani amastigotes for rattus rattus and the laboratory white rat. | amastigotes of a kenyan strain of leishmania donovani from a previously infected hamster were used to inoculate rattus rattus and the laboratory white rat intracardially. the animals were sampled at 2, 4, 6, and 12 weeks post-inoculation to determine infectivity and total parasite burdens in the liver and spleen. higher parasite burdens were observed in the livers and spleens of r. rattus. parasite culture indicated more generalized parasite dissemination compared to the white rat. demonstration ... | 1987 | 2894131 |
| vesicular systems (niosomes and liposomes) for delivery of sodium stibogluconate in experimental murine visceral leishmaniasis. | suppression of leishmania donovani liver amastigotes by sodium stibogluconate has been determined in a murine model of experimental visceral leishmaniasis. niosomal and liposomal drug formulations were equiactive and both increased drug efficacy by an order of magnitude compared with that of free drug. niosomes containing 30 mol % cholesterol were prepared from three different non-ionic surfactants and no significant difference in activity was detected among the different drug-loaded niosomes. b ... | 1988 | 2899143 |
| the therapeutic effect of sodium stibogluconate in balb/c mice infected with leishmania donovani is organ-dependent. | a study of the antileishmanial efficacy of sodium stibogluconate was carried out in balb/c mice. the drug was administered to leishmania donovani-infected animals on days 7 and 8 post-infection in one of three forms; free (40-50 mg sbv kg-1), liposomal, or niosomal (6.4-8.0 mg sbv kg-1) drug. on day 14 post-infection counts of the number of parasites present in the liver, spleen and bone marrow of treated and control animals showed that although all three drug preparations significantly reduced ... | 1988 | 2899637 |
| differential growth requirements of several leishmania spp. in chemically defined culture media. | 17 strains of leishmania from 4 species: brasiliensis, mexicana, donovani and garnhami have been continually cultured at 26 degrees c, in the absence of proteins, in a medium containing salts, glucose, d-ribose, 2-deoxyribose, hemin, tricine, hepes, 34 amino acids and intermediates of amino acid metabolism, 23 vitamins, 6 nucleotides and tetrahydrofolic acid. a wide variation in growth requirements was observed among leishmaniae which permitted the preparation of different minimum culture media ... | 1988 | 2901198 |
| requirements of defined cultivation conditions for standard growth of leishmania promastigotes in vitro. | the growth characteristics of l. chagasi (mhom/br/79/li01) and l. braziliensis (mhom/br/72/1670), the causative agents of visceral and muco-cutaneous leishmaniases, respectively, were compared. inoculum size clearly influences the growth course of both leishmania species, whatever the culture medium used (serum-supplemented media: glsh or rpmi, and a chemically defined medium: litr9). cultures initiated with low concentrations failed to promote cell growth, while typical growth curves were obtai ... | 1988 | 2901211 |
| identification of a surface membrane proton-translocating atpase in promastigotes of the parasitic protozoan leishmania donovani. | atpase activities were measured in surface membranes and mitochondria isolated from promastigotes of the parasitic protozoan leishmania donovani. the two enzymes were differentiated on the basis of ph optima, inhibitor sensitivity and by immunochemical methods. the surface-membrane (sm-) atpase had an activity of 100 nmol/min per mg of protein, which was optimal at ph 6.5. the enzyme was mg2+-dependent, partially inhibited by ca2+, and unaffected by na+ or k+. the sm-atpase was inhibited by orth ... | 1988 | 2906239 |
| chemotherapy of experimental visceral leishmaniasis in the opossum. | visceral leishmaniasis is a severe chronic disease of people and animals. the disease is caused by several subspecies of a protozoal organism, leishmania donovani. if not treated, visceral leishmaniasis is often fatal. the most commonly used chemotherapeutic agents to treat the disease are pentavalent antimonials, which can be toxic, must be administered by parenteral routes, and are sometimes ineffective. in this study, meglumine antimoniate, a pentavalent antimony, was compared with wr 6026, a ... | 1989 | 2918440 |
| effect of immunoglobulin m from normal human serum on leishmania donovani promastigote agglutination, complement-mediated killing, and phagocytosis by human monocytes. | serum from healthy, nonimmune humans contained immunoglobulin m (igm) antibodies that agglutinated leishmania donovani promastigotes, activated complement, and enhanced promastigote ingestion by human monocytes. the findings indicate that igm antibodies have the capacity to affect the initial interaction of l. donovani promastigotes with human host defenses. | 1989 | 2925255 |
| functional heterogeneity of macrophage precursor cells from spleen of leishmania donovani-infected and untreated mice. | we recently described the bone marrow-derived macrophage precursor, which is able to spontaneously and extracellularly kill protozoa of the genus leishmania. these nonadherent, nonphagocytic macrophage precursor cells are present in the spleen of healthy mice only in a small quantity. however, high numbers of proliferating macrophage precursors are isolated from the spleen of leishmania donovani-infected mice. macrophage precursors from spleens of diseased animals are able to kill spontaneously ... | 1989 | 2926141 |
| visceral leishmaniasis in congenic mice of susceptible and resistant phenotypes: immunosuppression by adherent spleen cells. | visceral leishmaniasis is one of several parasitic diseases of humans characterized by immune suppression. a murine model of disseminated leishmaniasis utilizing inbred strains of specific genetic constitution was used to study the mechanisms of immunosuppression elicited during the course of infection. resistant (lshr) and susceptible (lshs) strains of mice were challenged with amastigotes of leishmania donovani and evaluated as to immune status at intervals between 2 and 40 weeks after challen ... | 1985 | 2931376 |
| visceral leishmaniasis in congenic mice of susceptible and resistant phenotypes: t-lymphocyte-mediated immunosuppression. | this paper continues a comparative study (a. d. nickol and p. f. bonventre, infect. immun. 50:160-168, 1985) describing immune responses exhibited by congenic, lshs mouse strains c57b1/10 (cure) and b10.d2 (noncure) during the course of disseminated leishmaniasis. we report that sublethal whole-body irradiation of b10.d2 mice before challenge with leishmania donovani converted the noncuring mice to a curing phenotype. splenic lymphocytes from l. donovani-infected b10.d2 mice failed to proliferat ... | 1985 | 2931377 |
| leishmania donovani: cellular and humoral immune responses after primary and challenge infections in squirrel monkeys, saimiri sciureus. | cellular and humoral immune responses were studied in squirrel monkeys after primary and challenge infection with a khartoum strain (wr 378) of leishmania donovani. each of 7 squirrel monkeys, saimiri sciureus, was inoculated intravenously with 5 x 10(7) amastigotes/kg body weight, and one other monkey (control) was inoculated with uninfected hamster spleen homogenate. five infected monkeys recovered from visceral leishmaniasis and two infected monkeys died. three of the five squirrel monkeys wh ... | 1986 | 2940111 |
| cloning of leishmania donovani genes encoding antigens recognized during human visceral leishmaniasis. | in this report we describe the construction and analysis of a genomic library of leishmania donovani gene segments in the bacteriophage vector lambda gt11. this cloning vector permits the expression of parasite polypeptides as fusion products with escherichia coli beta-galactosidase. a group of 90 clones which express l. donovani antigens have been isolated from this library using various polyvalent antisera. many of these clones appear to encode parasite membrane antigens some of which are reco ... | 1986 | 2940461 |
| presence of a macrophage-mediated suppressor cell mechanism during cell-mediated immune response in experimental visceral leishmaniasis. | in susceptible balb/c mice, systemic intracellular infection with leishmania donovani provokes generation of adherent spleen cells which can suppress both mitogen- and specific-antigen-stimulated t-cell responses. to characterize the responsible suppressor cell, we irradiated (2,000 r) adherent spleen cells from l. donovani-infected mice or treated them with anti-thy-1.2 antibody plus complement. neither anti-t-cell treatment diminished the capacity to inhibit lymphocyte proliferative activity. ... | 1986 | 2945788 |
| [strains of the causative agent of visceral leishmaniasis from southeastern turkmenistan and the results of their trial with golden hamsters]. | | 1986 | 2948101 |
| evidence for common antigens on human non-adherent synoviocytes (type a) and peripheral monocytes. | the characterization of a homogeneous non-adherent synoviocyte (type a) cell population (greater than or equal to 95%) from non-rheumatoid patients by culturing the cells in the presence of forty percent foetal calf serum is reported. these cells were able to phagocyte latex beads, iron particles, fluoresceinated zymosan and yeast. furthermore, non-adherent synoviocytes were capable of being infected by the obligate intracellular parasite of peripheral monocytes leishmania donovani. indirect imm ... | 1986 | 2948255 |
| immune complex glomerulonephritis in experimental kala-azar. | in the present work we demonstrate that hamsters infected with l. donovani eliminate large quantities of immunoglobulins in the urine. this alteration is clearly a consequence of a conspicuous immune complex glomerulonephritis readily detectable 7 days after the beginning of infection. l. donovani antigens and hamsters immunoglobulins (igs) were revealed as granular deposits in the mesangial areas and contiguous loops of the glomeruli. histopathological alterations such as focal mesangial prolif ... | 1987 | 2951644 |
| [results of the serological examination of the population in the suppressed focus of human cutaneous leishmaniasis (kirovabad, azerbaijan ssr)]. | | 1987 | 2952870 |
| increased infectivity of stationary-phase promastigotes of leishmania donovani: correlation with enhanced c3 binding capacity and cr3-mediated attachment to host macrophages. | this study demonstrated that the greater infectivity of stationary-phase promastigotes of leishmania donovani is related to increased complement fixation on the parasite surface, resulting in increased binding to host mononuclear phagocytes (mps) via complement type 3 receptors (cr3). the in vivo infectivity of log- and stationary-phase promastigotes was compared by measuring parasite loads in the livers of balb/c mice 14 days after i.v. inoculation. the same populations were tested for their ab ... | 1987 | 2953670 |
| roles of cr3 and mannose receptors in the attachment and ingestion of leishmania donovani by human mononuclear phagocytes. | leishmania donovani is an obligate intracellular parasite of mammalian macrophages. two macrophage receptors, the mannose-fucose receptor (mfr) and the receptor for complement component c3bi, cr3, were examined for their roles in the attachment and ingestion of l. donovani by human monocyte-derived macrophages. two monoclonal antibodies which bind to the human cr3, anti-mo1 and anti-mac-1, inhibited both attachment and ingestion of l. donovani promastigotes after preincubation with human monocyt ... | 1988 | 2962944 |
| kinetics of gamma interferon binding and induction of major histocompatibility complex class ii mrna in leishmania-infected macrophages. | cells of the monocyte-macrophage series must carry out discrete accessory-cell functions during the process of antigen-specific t-cell activation. one of these functions is the cell-surface expression of major histocompatibility complex (mhc) class ii gene products, which are involved in the presentation of foreign antigen to t cells. previously, we reported that murine peritoneal macrophages infected with the obligate intracellular protozoan leishmania donovani had suppressed responses to gamma ... | 1988 | 2967971 |
| solubilization and kinetic characterization of mitochondrial adenosine triphosphatase from leishmania donovani promastigotes. | oligomycin-sensitive particulate atpase (mb atpase) from l. donovani promastigotes was solubilized by chloroform treatment. polyacrylamide gel electrophoresis revealed several protein bands, with the major one possessing atpase activity. the solubilized enzyme had mg2+-atpase and ca2+-atpase but no k+-dependent alkaline phosphatase activity. the mg2+-atpase activity was stimulated by monovalent cations and was not sensitive to oligomycin. hence it is referred to as f1 atpase. it had optimum acti ... | 1988 | 2970589 |
| specific serodiagnosis of visceral leishmaniasis using a leishmania donovani antigen identified by expression cloning. | a lambda gt11 expression library was constructed using mrna from the promastigote form of leishmania donovani (african isolate mhom/et/67/hu3). the library was screened with serum obtained from a patient who contracted visceral leishmaniasis in the sudan. several cdna clones which expressed beta-galactosidase/l. donovani antigen fusion proteins were isolated. one of these clones corresponded to a 60 kda membrane-associated antigen. by a western blot assay antibodies against the fusion protein we ... | 1988 | 2972929 |
| trypsin and chymotrypsin-like enzymes of the sandfly phlebotomus papatasi infected with leishmania and their possible role in vector competence. | phlebotomus papatasi (scopoli) is susceptible to infection with leishmania major yakimov & schokov and resistant to l. donovani laveran & mesnil. the possibility that susceptibility depends on midgut levels of trypsin and chymotrypsin-like (esterolytic) enzymes was investigated. infection with l. major reduced the trypsin-like activity to 93.5% and 86% of the control value at 20 and 30 h post feeding and increased it to 106% at 52 h. infection with l. donovani reduced trypsin-like activity to 64 ... | 1987 | 2979536 |
| leishmania infantum infection rates in phlebotomus perniciosus fed on naturally infected dogs under antimonial treatment. | dogs naturally infected with leishmania infantum nicolle were treated with three courses of meglumine antimoniate. changes were observed in the dogs' clinical signs, antibody titres and in infection rates of phlebotomus perniciosus newstead fed on the dogs. a large reduction in the sandfly infection rate was observed for 4-5 months after the first treatment. the use of antimonial drugs is advocated for the control of canine leishmaniasis and to reduce risks of l.infantum transmission. | 1987 | 2979550 |
| structural and ultrastructural hepatic changes in experimental canine leishmaniasis. | six 4 month-old beagles were inoculated with leishmania donovani infantum, three of them intraperitoneally (group a) and the other three intravenously (group b). the animals from group a were killed 109, 433 and 592 days after inoculation and animals from group b 109, 171 and 334 after inoculation. the liver of each of them was examined by means of light and electron microscopy. the lesions observed in both groups were very similar, but developed more rapidly in group b. a chronic hepatitis appe ... | 1988 | 2980240 |
| enzyme regulation in a trypanosomatid: effect of purine starvation on levels of 3'-nucleotidase activity. | crithidia fasciculata, a nonpathogenic relative of the leishmanial and trypanosomal pathogens of humans and animals, showed a 3'-ribonucleotidase activity similar to that in leishmania donovani. the level of 3'-nucleotidase activity in crithidia was regulated by the availability of purines in the culture medium. specifically, organisms obtained from culture medium depleted of purines contained elevated levels of enzyme activity compared to those grown in complete medium. the 3'-nucleotidase, loc ... | 1985 | 2981117 |
| human mononuclear phagocyte antiprotozoal mechanisms: oxygen-dependent vs oxygen-independent activity against intracellular toxoplasma gondii. | to determine if the oxygen-dependent and -independent antiprotozoal mechanisms with which the human mononuclear phagocyte is equipped to act against leishmania donovani operate against other intracellular parasites, oxidatively intact and deficient cells were challenged with toxoplasma gondii. fresh monocytes and lymphokine- or gamma-interferon (ifn-gamma)-activated macrophages from normal individuals killed 35% and 50% of t. gondii within 6 hr, respectively, and each of these cell populations i ... | 1985 | 2981929 |
| [leishmaniasis in dogs. clinical course of infection, diagnosis and therapy trials following experimental infection of beagles with leishmania donovani (calcutta strain)]. | | 1985 | 2983657 |
| protonmotive force-driven active transport of d-glucose and l-proline in the protozoan parasite leishmania donovani. | midlogarithmic phase leishmania donovani promastigotes accumulate 2-deoxy-d-glucose (2-dglc) and l-proline, maintaining concentration gradient factors across the surface membrane of 78.7 and 60, respectively. cyanide (1 mm) and iodoacetate (0.5 mm) inhibited the transport of both substrates. l-proline uptake was also inhibited by 2-dglc (10 mm). transport of neither substrate was affected by na+, phlorizin, or ouabain, indicating the sodium-independent transport of both systems. however, n',n'-d ... | 1985 | 2984665 |
| the respiratory burst is not required for killing of intracellular and extracellular parasites by a lymphokine-activated macrophage cell line. | the macrophage cell line, ic-21, was found to be incapable of producing the oxygen products associated with the respiratory burst. however, ic-21 cells were activated by lymphokine (lk) to kill intracellular (leishmania donovani amastigotes) and extracellular (schistosoma mansoni larvae) parasites, as well as tumor cells. in each case, the cytotoxicity exhibited by activated ic-21 cells and activated peritoneal macrophages was indistinguishable. however, nonactivated ic-21 cells were unable to k ... | 1985 | 2988973 |
| resistance of leishmanial phosphatases to inactivation by oxygen metabolites. | leishmania donovani promastigotes produce large quantities of two distinct acid phosphatases; a tartrate-resistant enzyme is localized to the external surface of the plasma membrane, and a tartrate-sensitive enzyme is secreted into the growth medium. it was shown previously that preincubation of human neutrophils and macrophages with the tartrate-resistant phosphatase markedly reduced the ability of these host cells to produce superoxide anions in response to stimulation with the activator formy ... | 1985 | 2995435 |
| electron microscopy of leishmania donovani in splenic aspirates from patients with visceral leishmaniasis during treatment with sodium stibogluconate. | studies were made of the ultrastructure of amastigotes of leishmania donovani before and during treatment of patients with sodium stibogluconate. the most consistent effects of treatment on the amastigotes were a reduction in average size, greater irregularity of the cell outline, and a moderate increase in the electron density of the cytoplasm associated with a greater concentration of ribosomes. it is suggested that the drug affects active transport functions or permeability of the plasma memb ... | 1985 | 3000304 |
| leishmania donovani: surface membrane acid phosphatase blocks neutrophil oxidative metabolite production. | we show that a purified preparation of the prominent tartrate-resistant acid phosphatase (e.c.3.1.3.2), isolated from the external surface of the intracellular parasite leishmania donovani (promastigote form), inhibits toxic oxidative metabolite production of neutrophils. preincubation of a neutrophil suspension (2.5 x 10(6) cells/ml) for 15 min at 37 c with 250 units (1 unit equals 1 nmole of 4-methylumbelliferyl phosphate cleaved per hr at ph 5.5) of the acid phosphatase in krebs-ringer phosph ... | 1985 | 3000810 |
| [big spleen, big problems]. | the history of a moroccan girl is described with splenomegaly, lymphadenopathy and pancytopenia after a holiday in her native country. bone marrow smears were considered negative for leishmaniasis in four different laboratories. all other diagnostic options could also not be confirmed. reexamination of the bone marrow smears in a laboratory for tropical diseases revealed leishmania donovani organisms. treatment with sodium antimony gluconate was successful. epidemiology, symptoms and diagnostic ... | 1985 | 3006280 |
| detection and characterization of leishmania species and strains from mammals and vectors by hybridization and restriction endonuclease digestion of kinetoplast dna. | leishmania parasites from animals, man or insect vectors were characterized by the gel electrophoresis of restriction endonuclease enzyme-produced mitochondrial (kinetoplast) dna (kdna) fragments and/or by dna-dna hybridization with 32p-labelled cloned, or uncloned, kdna fragment probes from type isolates. the electrophoretic separation of kdna fragments is a sensitive method for detecting genetic similarities and differences among leishmania. parasites with similar kdna restriction fragment pat ... | 1986 | 3010541 |
| cellular resistance to protozoal infection. | several factors appear to determine cellular resistance to protozoal infection. as judged by the interaction at the cellular level between the oxygen-dependent and -independent antimicrobial mechanisms of the human mononuclear phagocyte and the intracellular protozoa, toxoplasma gondii and leishmania donovani, these determinants include the cell's state of maturation and activation, the magnitude of the phagocyte's oxidative burst capacity, the ability of the cell to respond specifically to para ... | 1986 | 3010809 |