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[ultrastructural localization of leishmania donovani antigen by immunogold labeling technique].by using lowicryl k4m, a kind of low temperature embedding resin, to embed promastigotes of leishmania donovani at -30 degrees c, the protozoal structure was well preserved when visualized by electron microscope. we have determined the distribution of the promastigote antigen of human and canine isolates of leishmania donovani from sichuan using two monoclonal antibodies combined with biotinylated goat antimouse igg and streptavidin/colloidal gold conjugates. the results showed that the antigen ...19902364499
lysosomal depletion in macrophages from spleen and foot lesions of leishmania-infected hamster.analysis of lysosomes through acid phosphatase cytochemistry at the electron microscopy level has been performed in spleen and foot lesions from leishmania-infected hamsters. the results showed that there is lysosomal depletion in macrophages from leishmania donovani chagasi-infected hamster spleen and similar findings were obtained from foot lesions of leishmania mexicana amazonensis-infected hamsters. the distribution of acid phosphatase and thiamine pyrophosphatase was also examined in the go ...19902373189
leishmania braziliensis in the squirrel monkey: development of primary and satellite lesions and lack of cross-immunity with leishmania donovani.three female and 2 male adult laboratory-reared squirrel monkeys (saimiri sciureus) that previously had been inoculated with leishmania (leishmania) donovani and had recovered from experimental visceral leishmaniasis were each inoculated intradermally at the dorsal base of the tail with 2.2 x 10(7) culture-derived promastigotes of leishmania (viannia) panamensis. the progression and regression of subsequent lesions were examined for 36 wk in all 5 monkeys after which 3 of the monkeys were killed ...19902380874
acivicin: a highly active potential chemotherapeutic agent against visceral leishmaniasis.acivicin, a chlorinated amino acid antibiotic, is found to be remarkably effective in killing both the vector and the host form of the parasitic protozoa, leishmania donovani, the causative agent for visceral leishmaniasis or kala-azar. the ed50 (50 nm) for the pathogenic amastigote form in in vitro screening system is significantly lower than the reported values for other drugs under trial. the drug irreversibly inactivates both in vitro and in vivo carbamyl phosphate synthetase ii, the first e ...19902383250
partial purification and characterization of a soluble protein kinase from leishmania donovani promastigotes.a soluble protein kinase from the promastigote form of the parasitic protozoon leishmania donovani was partially purified using deae-cellulose, sephadex g-200 and phosphocellulose columns. the enzyme preferentially utilized protamine as exogenous phosphate acceptor. the native molecular mass of the enzyme was about 85 kda. mg2+ ions were essential for enzyme activity; other metal ions, e.g. ca2+, co2+, zn2+ and mn2+, could not substitute for mg2+. camp, cgmp, ca2+/calmodulin and ca2+/phospholipi ...19902384743
cyclosporin a treatment converts leishmania donovani-infected c57bl/10 (curing) mice to a noncuring phenotype.cyclosporin a prevents visceralization of leishmania major infection of balb/c mice (n. c. behforouz, c. d. wenger, and b. a. mathison, j. immunol. 136:3067-3075, 1986; w. solbach, k. forberg, e. kammerer, c. bogdan, and m. rollinghoff, j. immunol. 134:702-707, 1986). we report that cyclosporin a exacerbates disseminated leishmaniasis caused by l. donovani in c57bl/10 mice. normal mice challenged with 5 x 10(6) amastigotes intravenously cleared the infection within several months by spontaneous ...19902387638
evaluation of the stability of a soluble intradermal skin test antigen preparation in american visceral leishmaniasis. 19902389311
epidemiology of leishmaniases in kenya. natural host preference of wild caught phlebotomine sandflies in baringo district, kenya.host preference of wild caught phlebotomine sandflies was studied in marigat, baringo district, kenya, an endemic focus for both leishmania donovani laveran & mensel and l. major yakimov & schokhov using precipitin test of blood meals. sandflies of the phlebotomus rondani & berte and sergentomyia franc & parrot genera were encountered blood fed and resting in nine different habitats which were investigated. analysis of their blood meals revealed a distinct host preference between the phlebotomus ...19902390954
leishmaniasis in sardinia. iv. epidemiological appraisal of cutaneous leishmaniasis and biochemical characterization of isolates.cutaneous leishmaniasis (cl) is endemic in sardinia where 250 cases were reported from 1922 to 1988. the province of sassari, in the north of the island, shows the highest number of cases. the vertical distribution of localities where cases had occurred is analysed and the age distribution of cases is given. isolation of parasites was attempted in 12 cases, but successful growth of leishmania was obtained from three cultures only. the stocks belonged to two different zymodemes of l. infantum: zy ...19902391725
effect of ureastibamine on leishmania donovani amastigote.ureastibamine, a pentavalent antimonial, reduced the parasitic load in the 60-day model of infection of l. donovani in hamsters. it also inhibited the in vivo multiplication of i donovani amastigotes in hamster peritoneal macrophages. no inhibition in either promastigote multiplication or amastigotes transformation was noted with filtrate obtained after incubation of the drugs for 72 h in the macrophage culture. incubation of macrophages with ureastibamine revealed an impairment in the uptake of ...19902397943
antithymocyte serum suppression of immunity in mice immunized to leishmania donovani.mice immunized with a glucan-killed parasite vaccine exhibited enhanced resistance to leishmania donovani infection as evidenced by decreased hepatic parasite burdens when compared to unvaccinated controls. this resistance was not seen in mice immunized with killed parasites alone. glucan vaccination resulted in increased resistance at day 6, but this effect was no longer present by day 20 of the experiment. treatment of vaccinated and control mice with antithymocyte sera abrogated protection ag ...19902403241
the leishmanial lipophosphoglycan: a multifunctional molecule.a striking characteristic of leishmanial parasites is their ability to avoid destruction in hostile environments throughout their life cycle. to survive, the parasites must have evolved specialized molecules. one such molecule that has received considerable attention is an unusual glycoconjugate called lipophosphoglycan. the macromolecule is the major cell surface glycoconjugate of all leishmania promastigotes. this minireview summarizes current information on the structure and possible function ...19902404784
analyses of surface membrane carbohydrates in parasitic flagellates of the order kinetoplastida using lectins.crithidia fasciculata, leishmania donovani, leishmania major, leishmania mexicana amazonensis, leishmania tropica, leishmania tarentolae, trypanosoma sp. from formosan bats (tb), trypanosoma lewisi, trypanosoma musculi, and different strains of trypanosoma cruzi (tc) were cultivated at 27 degrees c in a liquid culture medium. flagellates harvested from log phase culture were analyzed for their lectin agglutinating characteristics with concanavalin a (con a), peanut agglutinin, ricinus communis a ...19901696387
lipophosphoglycan and secreted acid phosphatase of leishmania tropica share species-specific epitopes.several species-specific monoclonal antibodies (t11, t13-t15) which only react with leishmania tropica, recognize phosphorlated carbohydrate epitopes on lipophosphoglycan and the structurally related molecule, phosphoglycan, which is shed by promastigotes into spent culture medium. during immunoaffinity isolation of [32p]orthophosphate-labeled phosphoglycan on monoclonal antibody t15 conjugated to sepharose 4b, a high-mr component (approx. 200,000) was co-purified. the latter material is metabol ...19901697935
expression of a repeating phosphorylated disaccharide lipophosphoglycan epitope on the surface of macrophages infected with leishmania donovani.murine peritoneal macrophages were infected with living, virulent leishmania donovani promastigotes. at intervals after infection, the macrophage surfaces were probed for the expression of lipophosphoglycan (lpg) epitopes by immunofluorescence with anti-lpg monoclonal antibodies. a repeating phosphorylated disaccharide epitope of lpg was detected as early as 5 to 10 min postinfection and was initially localized to the immediate area of internalization of the promastigote into the macrophage. the ...19901699895
evidence of transferrin binding sites on the surface of leishmania promastigotes.a glycoprotein of 78,000 molecular mass (78 kda), associated with the membrane of leishmania infantum promastigotes, was identified and immunopurified by monoclonal antibody (mab) ld9 produced against isolated membrane preparations. mab ld9 was subsequently found to bind to human transferrin, also of 78 kda. binding of ld9 to transferrin was completely abolished when the mab was preabsorbed by leishmania membranes, thereby indicating that the 78-kda leishmania membrane-associated glycoprotein an ...19901702420
species and stage specificity of leishmania donovani antigens.monoclonal antibodies d2 and d13 were produced in mice using leishmania donovani promastigote membrane fractions. to study the species and stage specificity of the antigens recognized by these antibodies, we examined amastigotes prepared in vitro and cultured promastigotes by indirect immunofluorescence with monoclonal antibodies d2 and d13. monoclonal antibody d2 showed weak reactivity for 9 of 9 strains of l. donovani complex promastigotes and 8 of 9 amastigotes. in contrast, only 2 of 22 stra ...19911704058
positive response to sodium antimony gluconate administration in visceral leishmaniasis seropositive patients.in a prospective study conducted in mymensingh district of bangladesh, 1, 273 patients were assessed for the presence of visceral leishmaniasis (vl). sodium antimony gluconate (sag) was successfully administered to 715 patients with parasitologically confirmed infection. in the remaining 558, although there was clinical indication of vl, leishmania donovani parasites could not be demonstrated. administration of sag in this group was on the grounds of the prevailing symptoms, exclusion of malaria ...19911645929
evaluation of different assay techniques to assess the interaction between leishmania major and l. infantum promastigotes and u937 cells.adherence of leishmania major and l. infantum promastigotes to u937 cells was determined by microscopic observation or by using radiolabelled parasites. with both methods l. infantum showed a greater adherence. aspecific attachment to plastic was greater for l. major. the possible implications of these findings in connection with disease pathogenesis are briefly discussed.19911648163
a cloned kinetoplast dna mini-circle fragment from a leishmania spp. specific for post-kala-azar dermal leishmaniasis strains.dna-dna hybridization techniques have been found to be very useful in the classification and identification of leishmania parasites. we report here the cloning of a mini-circle from leishmania strain ur6 in a plasmid and subcloning of the mini-circle fragments in m13 mp9. clone mlurk32, containing a 560 bp fragment of mini-circle, has been found to have unique specificity. application of this specific probe in identifying different leishmania isolates reveals that the probe reacted only with str ...19911649427
post-kala-azar dermal leishmaniasis: a case report strikingly resembling lepromatous leprosy.an adult man with post-kala-azar dermal leishmaniasis who had lessons distributed in a manner strikingly similar to lepromatous leprosy is described. he was mistakenly treated with multidrug therapy as recommended by the who expert committee on leprosy. all investigations including slit-skin smears, histopathology, culture for leishmania donovani and an indirect fluorescent antibody test to confirm post-kala-azar dermal leishmaniasis proved futile. the diagnosis was ultimately based on the previ ...19911651437
surgical pathology of the liver in hiv infection.in the 6-year period 1984-1989, 101 liver biopsies or 'needle necropsies' from human immunodeficiency virus positive patients were examined histologically. of these, only nine showed no abnormality whatsoever. the commonest histological findings were either fatty change or changes related to co-existent chronic viral hepatitis. granulomas were seen in 15 cases, four of which were positive for acid-fast bacilli. a range of organisms were recorded: cytomegalovirus (4); histoplasma capsulatum (1); ...19911653181
visceral leishmaniasis: a difficult diagnosis and unusual causative agent.in a young man who had a prolonged fever of unknown origin, hepatosplenomegaly, and progressive pancytopenia, stained smears, blood-agar cultures of bone marrow, and serologic testing for antileishmanial antibodies were negative. biopsies from liver and bone marrow were uninformative. visceral leishmaniasis was diagnosed only after splenectomy, when amastigotes were finally cultured from the spleen. the parasite was shown to be an unusual leishmanial parasite, possessing a mixture of intrinsic b ...19911654358
fine structure of leishmania donovani in bone marrow aspirates from a patient with visceral leishmaniasis before and during treatment with sodium stibogluconate.the fine structure of leishmania donovani amastigotes has been studied in bone marrow aspirates from a 4-year-old girl with visceral leishmaniasis before and during treatment with sodium stibogluconate. free amastigotes in the bone marrow were forming junctions with previously undescribed cytoplasmic buddings of macrophages prior to engulfment; these buddings were suggested to be transient parasitophorous vacuoles. three stages of infection within macrophage parasitophorous vacuoles were identif ...19911654589
an atp-independent catenating enzyme from the kinetoplast hemoflagellate leishmania donovani.an enzyme from leishmania donovani that catenates monomeric pbr322 into huge catenanes has been isolated and characterized. the enzyme also decatenates kinetoplast dna networks into covalently closed monomeric circles and relaxes supercoiled pbr322. the catenation, decatenation and relaxation reactions do not require atp. the formation of topological isomers of unique linking numbers suggest that the enzyme is a type ii dna topoisomerase.19911656969
ultrastructural study on the antileishmanial effect of 1,2-dimethyl-3-methoxy carbonyl-4-(2-nitro-4,5-dimethoxyphenyl) pyrrole in hamsters.an ultrastructure study was carried out on the effect of a standard drug sodium stibogluconate and a newly identified active cdri compound 87/305 [1,2-dimethyl-3-methoxy carbonyl-4-(2-nitro-4,5-dimethoxyphenyl) pyrrole] on amastigotes of leishmania donovani in macrophage cells of spleen of infected hamsters. while na-stibogluconate exerted its effect by activating the digestion capacity of host macrophages, compound 87/305 was directly lethal to the parasites without, exerting any effect on the ...19911657768
hydrogen peroxide-mediated toxicity for leishmania donovani chagasi promastigotes. role of hydroxyl radical and protection by heat shock.leishmania must survive despite exposure to the toxic oxidant hydrogen peroxide (h2o2) during phagocytosis by macrophages. we investigated the mechanism of h2o2 toxicity for l. donovani chagasi promastigotes, and factors responsible for their relative h2o2 resistance. there was a dose-dependent toxic effect of h2o2 for promastigotes isolated during logarithmic phase of growth. in contrast, stationary phase promastigotes were less susceptible to h2o2 toxicity, and more infectious for balb/c mice. ...19911658042
leishmanial blepharo-conjunctivitis.we describe a case of blepharo-conjunctivitis due to leishmania donovani in association with nodules of post kala azar dermal leishmaniasis (pkdl) on the chin. the diagnosis was confirmed by isolation of the parasite in culture. direct implantation of the parasite by contaminated fingers from the chin nodules to the eye is suggested as the mode of spread. the role of cell-mediated immunity, (cmi) in restricting the skin lesions on the chin for 37 years at the same site, was suspected. this is on ...19911667830
structural analysis of a glycosylphosphatidylinositol glycolipid of leishmania donovani.a glycosylphosphatidylinositol (gpi) glycolipid antigen recognized by sera from patients with visceral leishmaniasis was isolated from leishmania donovani promastigotes. the carbohydrate moiety was cleaved from the lipid part by digestion with specific phosphatidylinositol phospholipase c. after separation, structural analysis was carried out on the phosphorylated inositol oligosaccharide and the alkylacyl glycerol. the following major structures were found: [formula: see text] the presence of t ...19911668717
[enzyme activity in leishmania].some enzymes produced by the protozoon leishmania can have an important role in the intraphagocytic survival of the parasites. the production of hydrolytic enzymes by promastigotes belonging to two leishmania sp. (major and infantum) and maintained in different experimental conditions was evaluated. the proteolytic activity was moderate, while superior was the production of acid phosphatase in l. infantum. an increase of the trypsin-like activity was observed after incubation of protozoa for 24 ...19911668970
leishmania donovani chagasi: new clinical variant of cutaneous leishmaniasis in honduras.during surveillance for endemic visceral leishmaniasis on an island off the pacific coast of honduras, an unusual form of cutaneous leishmaniasis was encountered. by clinical and laboratory criteria, 17 cases were identified over 5 months; children aged 4 to 15 years were primarily affected. lesions were generally few in number, small, always papular, and non-ulcerative, even when present for several years. patients with skin lesions seemed otherwise healthy and were well nourished. montenegro s ...19911670724
amplification and molecular cloning of the imp dehydrogenase gene of leishmania donovani.a mutant (mpa100) strain of leishmania donovania was generated from a wild type (d1700) population by virtue of its ability to survive the selective pressure of gradually increasing concentrations of mycophenolic acid (mpa), an inhibitor of imp dehydrogenase (impdh) activity. comparative growth experiments revealed that the mpa100 strain was 100-fold more resistant to mpa toxicity and cross-resistant to ribavarin, another inhibitor of impdh. a direct comparison of impdh levels in d1700 and mpa10 ...19911671039
effect of nifedipine on leishmania donovani infection in-vivo and in-vitro: chemiluminescence responses of peritoneal macrophages and neutrophils.after peritoneal macrophages had been exposed to different concentrations of nifedipine (10-120 ng ml-1) there was a significant increase (p less than 0.001) in the percentage of leishmania donovani infected macrophages compared with controls. parasite load was also significantly increased (p less than 0.001) in nifedipine-treated, l. donovani infected, balb/c mice, compared with untreated, infected mice, post-inoculation. peak chemiluminescence responses were significantly depressed (p less tha ...19911672903
liposomal amphotericin b in drug-resistant visceral leishmaniasis.the treatment of visceral leishmaniasis (vl) may be complicated by drug toxicity or intolerance, and by drug resistance. amphotericin b (amb) is effective, but its use is limited by toxicity: renal impairment, anaemia, fever, malaise, and hypokalaemia are common. liposomes have been proposed as an effective way to target drugs at macrophages, which are the cells infected in visceral leishmaniasis. in animals amb incorporated into liposomes is highly effective against experimental leishmaniasis, ...19911673494
a nuclear dna probe for the identification of strains within the leishmania donovani complex. 19911673931
evaluation of in-vitro leishmanicidal activity of hydrazones of thiophene carboxaldehydes against promastigotes of leishmania infantum and leishmania tropica.the lack of leishmanicidal drugs has prompted the synthesis and testing of new hydrazones of thiophene carboxaldehydes against three leishmania strains. the compounds were obtained by condensation of appropriate hydrazines with thiophene 2-carboxaldehyde (series 1), thiophene 3-carboxaldehyde (series 2), and 5-nitrothiophene-2-carboxaldehyde (series 3). leishmanicidal activity was assessed against promastigotes of leishmania strains, grown in-vitro in nutrient broth medium complemented with fres ...19911676064
the mrna coding for the nucleosomal protein h2a of leishmania is polyadenylated and has stem-loops at the 3' end. 19911679534
presentation of leishmania donovani promastigotes occurs via a brefeldin a-sensitive pathway.for the presentation of leishmania promastigotes to polyclonal cd4+ t cells, a processing period within activated macrophages of 3-4 h is required. presentation can be inhibited by both chloroquine and brefeldin a (bfa), the latter implicating a requirement for newly synthesized mhc class ii molecules. this inhibition is both reversible and specific, in that bfa did not inhibit mixed lymphocyte reaction stimulation by these infected macrophages. immunogold labeling demonstrated that class ii was ...19911680697
interferon-gamma inhibits the efficacy of interleukin 1 to generate a th2-cell biased immune response induced by leishmania major.splenic adherent cells from l. major-infected resistant and susceptible mice were restimulated in vitro and analyzed for the expression of il-1 activity. three weeks or later after infection, cells from parasite infected susceptible balb/c mice produced substantially more il-1 activity than those from non-infected controls or from l. major-infected resistant c57bl/6 animals. more than 95% of the il-1 bioactivity was mediated by il-1 alpha, as determined by blocking experiments with an anti-il-1 ...19911680802
guillain-barré syndrome as presenting manifestation of visceral leishmaniasis. 19911682557
canine leishmaniasis associated with systemic vasculitis in two dogs.two cases of canine leishmaniasis associated with systemic necrotizing vasculitis are described. the main macroscopic lesions were haemorrhagic in type; histopathological changes confirmed a vascular lesion affecting small arteries of several organs (skin, intestinal tract, kidney, urinary bladder, mesenteric lymph nodes, adrenal gland, myocardium, lung, eye and choroid plexus). the presence of the parasite was confirmed with a specific immunocytochemical stain. the possibility of an immunologic ...19911684801
application of atp measurement to evaluation of the growth of parasitic protozoa in vitro with a special reference to pneumocystis carinii.1. there was a significant correlation between the increase in the number of entamoeba histolytica, trichomonas vaginalis, giardia lamblia and leishmania donovani in culture, and their atp contents determined by luciferase reaction. 2. the similar correlation was also demonstrated between the decreased number of e. histolytica in the presence of an anti-amebic quassinoid and the nucleotide content in vitro. 3. in the case of pneumocystis carinii, the numbers of the organism remained relatively c ...19911685366
oxidation of leucine by leishmania donovani.the metabolism of leucine by leishmania donovani was investigated. washed promastigotes were incubated with [1-14c]- or [u-14c]leucine or [1-14c]alpha-ketoisocaproate (kic) and 14co2 release was measured. the amount of kic-derived acetyl-coa oxidized in the citric acid cycle was computed. promastigotes from mid-stationary phase cultures oxidized each of these labeled substrates less rapidly than cells from late log phase cultures, and significantly less acetyl-coa derived from kic oxidation was ...19911687827
evidence for translational control of beta-tubulin synthesis during differentiation of leishmania donovani.tubulin biosynthesis was rapidly induced during transformation of the mammalian (amastigote) stage of the kinetoplastid parasite leishmania donovani to flagellated promastigotes. however, transcription of beta-tubulin genes occurred constitutively, as judged by nascent rna synthesis in isolated nuclei and northern blotting of steady-state mrna. two mrna species of 2.2 and 2.4 kb were shared by the two cell-types, while a third 2.6 kb species, constituting about 20% of the total, was present in l ...19911745547
priming of phagocytes by cytokines and water-soluble products of lipid peroxidation.it is well known that during certain pathological processes phagocytes acquire the ability to generate activated oxygen species during phagocytosis. the priming of phagocytes by cytokines and water-soluble products of lipid peroxidation (lpo) is described. preincubation of human polymorphonuclear leukocytes (pmnl) with the water-soluble products of lpo or oxidised liposomes for 15-20 min at 37 degrees c enhanced their functional activity when they were stimulated by opsonised zymosan or latex pa ...19911751754
studies on the leishmaniases in the sudan. 3. clinical and parasitological studies on visceral and mucosal leishmaniasis.the epidemiological, clinical and laboratory findings of 27 patients with visceral leishmaniasis (vl) and six with mucosal leishmaniasis (ml) in sudan are described. the diagnosis was confirmed by the demonstration of amastigotes in bone-marrow in 20 cases with vl (80%) and impression smears in 2 cases with ml. the enzyme-linked immunosorbent assay and direct agglutination test were positive in all the sera tested. the leishmanin test was positive in all patients with ml, the diameter of the rea ...19911755050
post-kala-azar anterior uveitis: demonstration of leishmania parasites in the lesion. 19911755051
direct agglutination test for diagnosis and sero-epidemiological survey of kala-azar in the sudan.132 patients with suspected kala-azar (visceral leishmaniasis) were included in a prospective study to compare the performance of the direct agglutination test (dat) with smears of lymph node, bone marrow and splenic aspiration. a titre greater than 1:3200 was considered positive. 67 patients provided positive smears and 65 were smear-negative. compared with the results obtained from smears, the sensitivity of the dat was 94% and its specificity 72%. of 18 patients who were negative by smears bu ...19911755052
human urine stimulates growth of leishmania in vitro.enhancement of trypanosomatid metacyclogenesis by insect urine components led us to test the effect of human urine as a culture additive. the addition of 1-5% urine to schneider's drosophila medium containing 10% foetal calf serum enhanced the growth of 11 leishmania strains representing 8 different taxonomic groups. cell division was stimulated in cultures with non-dividing organisms. peak cell density was increased, as was the efficiency with which l. donovani could be isolated from infected h ...19911755054
cutaneous leishmaniasis and leishmania infantum. 19911755077
detection of variable dna repeats in diverse eukaryotic microorganisms by a single set of polymerase chain reaction primers.we cloned and sequenced a variable dna repeat from trichomonas vaginalis, a flagellated protozoan parasite. targeting of this repeat in the polymerase chain reaction resulted in complex and intense product patterns for a wide variety of eukaryotic microorganisms, including the pathogenic protozoan parasites t. vaginalis, giardia lamblia, leishmania donovani, three species of trypanosoma, and four species of acanthamoeba; the nonpathogenic protozoans, paramecium tetraurelia and tetrahymena thermo ...19911757544
heterogeneity of the genes encoding the major surface glycoprotein of leishmania donovani.the major surface glycoprotein of leishmania (gp63) is present on all known species of leishmania and likely plays an integral role during the infection of macrophages in the mammalian host. to identify regions of gp63 which may be of functional significance, the nucleotide sequence of a gene encoding gp63 of leishmania donovani was determined and compared to the sequences reported for gp63 genes of leishmania major and leishmania chagasi. the gp63 nucleotide and predicted protein sequence was h ...19911762629
[the determination of the species specificity of leishmania antibodies in different groups of human sera].species-specificity of two serological tests has been compared: indirect immunofluorescence test and c-elisa using antigens prepared of 7 leishmania species of various groups of human sera, including sera from healthy donors; sera of patients with various tropical parasitoses; sera containing rheumatoid factor and antinuclear antibodies; sera of patients with visceral leishmaniasis (vl); sera of normal subjects arrived from regions endemic for vl; sera of students arrived in czechoslovakia from ...19911770880
[immunologic complications of visceral leishmaniasis].this study concerns 3 cases of visceral leishmaniasis with various immunological complications. one patients showed a life-threatening activation of macrophages, characterised by haemophagocytosis in the bone marrow, pancytopenia, hypofibrinogenaemia and hypertriglycerideamia. a selective deficiency of igg subclasses persisting for months was found in all 3 cases, the clinical relevance of which is unclear. one case manifested the already well known transient decrease of cell mediated immunity t ...19911775144
biopterin conversion to reduced folates by leishmania donovani promastigotes.the ability of leishmania donovani promastigotes to proliferate in folate-deficient medium supplemented with pterins suggests that pterins can serve as a source of folate in these parasites [16]. using reversed-phase high-performance liquid chromatography, the ability of intact l. donovani to transform [3h]biopterin into tetrahydrofolates was demonstrated. radioactivity was primarily associated with 5-methyltetrahydrofolate and 10-formyltetrahydrofolate. a mutant strain of l. donovani, mtxa5, th ...19911775157
liposomal amphotericin b in the treatment of visceral leishmaniasis.a case of visceral leishmaniasis unresponsive to several course of treatment with standard drugs, was successfully cured by a 21 day course (50 mg/day) of liposomal amphotericin b (ambisome, vestar inc.). the efficacy of the ambisome formulation is supported by experimental studies on leishmania donovani infected balb/c mice where ed50 values of ambisome and conventional amphotericin b were 0.15-0.25 and 0.95-4.9 mg/kg, respectively. a lack of toxicity of the ambisome formulation was noted in bo ...19911778888
biochemical and immunological characterization of exometabolites from an indian strain of leishmania donovani promastigotes grown in a chemically defined medium.exometabolites (exom) of an indian strain of leishmania donovani promastigotes isolated from a chemically defined medium by ultrafiltration consisted of proteins, glycoproteins, lipid and lipophosphopolysaccharide (lpps). lpps of mr 40-28 kda in sds-page could be labelled metabolically with [32p]-phosphate and recovered in the aqueous phase of hot-phenol-water extraction of exom (pe-aq) along with a glycoprotein of mr 150-130 kda (gp150-130). these two molecules could be eluted from de-52 column ...19911779962
molecular karyotype and chromosomal localization of genes encoding two major surface glycoproteins, gp63 and gp46/m2, hsp70, and beta-tubulin in cloned strains of several leishmania species.the molecular karyotypes of several leishmania isolates (leishmania amazonensis, leishmania braziliensis, leishmania guyanensis, leishmania panamensis, leishmania donovani, leishmania major, leishmania aethiopica, leishmania tropica, leishmania enriettii) have been analyzed by clamped homogeneous electric field (chef) gel electrophoresis. the chromosomal localization of genes encoding 2 major surface glycoproteins, gp63 and gp46/m2, heat shock protein 70 (hsp70), and beta-tubulin was determined ...19911779988
isolation of the 66-kilodalton polypeptide from promastigotes of leishmania donovani as a ligand molecule for binding to macrophages.a 66-kda major plasma membrane-associated molecule of promastigotes of leishmania donovani (ur6) was purified by affinity chromatography. the immunoreactivity of the 66-kda molecule was lost upon exposure to heat or treatment with trypsin. the metaperiodate oxidation significantly reduced its immunoreactivity. the 66-kda molecule is, therefore, glycoprotein in nature. with a fluorescent probe, the 66-kda molecule was found to be located on the tip of flagellum and on the kinetoplast. the exposur ...19911784082
initial rate measurements of cellular nucleoside transport: time course, initial curvature of time curves and metabolism. 19911789250
iridoids: a new class of leishmanicidal agents from nyctanthes arbortristis.iridoid glucosides (arbortristosides a [i], b [2], c [3], and 6beta-hydroxy-loganin [4] isolated from the traditional plant nyctanthes arbortristis show antileishmanial activity in both in vitro (against amastigotes in macrophage cultures) and in vivo (in hamsters) test systems.19911791475
putrescine uptake regulation in response to alpha-difluoromethylornithine treatment in leishmania infantum promastigotes.the putrescine uptake/efflux regulation and their regulatory role on intracellular polyamine pools have been studied in the parasitic protozoa leishmania infantum. putrescine uptake was age-dependent with maximal values in logarithmic phase promastigotes and minimal in stationary phase. moreover, putrescine uptake was activated in response to depletion of intracellular polyamines by alpha-difluoromethylornithine (dfmo)--a well known irreversible enzyme-activated inhibitor of ornithine decarboxyl ...19911791826
effect of trypsin and 2-mercaptoethanol on the exposure of sugar residues on the surface of leishmania donovani chagasi.using transmission electron microscopy, gold-labeled lectins, morphometry and enzyme-linked lectin assay, we could show that treatment of promastigotes of leishmania donovani chagasi with trypsin did not interfere with the binding of lectins (concanavalin a, peanut agglutinin, wheat germ agglutinin and ricinus communis agglutinin) to the parasite surface. these observations are in agreement with results we previously obtained using a biochemical approach. treatment of fixed promastigotes with 2- ...19911792223
leishmania infantum: polyamine biosynthesis and levels during the growth of promastigotes.1. decarboxylation of polyamine precursors: l-ornithine and l-methionine was determined along the growth curve of leishmania infantum promastigotes in vivo, reaching maximum values on day 2 post-inoculum (mid-logarithmic phase). 2. maximum values of l-ornithine and l-methionine decarboxylation were: 1.97 +/- 0.28 nmol co2/hr/10(7) promastigotes and 3.18 +/- 0.34 nmol co2/hr/10(7) promastigotes, respectively. 3. total (free + conjugated) polyamine content was closely related with the proliferativ ...19911794446
gamma interferon production by lymphocytes from children infected with l. chagasi.the present study was performed to evaluate the ability of lymphocytes from 18 children living in an endemic area of visceral leishmaniasis (vl) to produce gamma-interferon. these children had no previous history of vl and were considered to be infected with leishmania chagasi based on leishmanial seroconversion. the gamma ifn levels were determined by radioimmunoassay on supernatants of lymphocyte cultures (3 x 10(6)/ml) stimulated with pha (final dilution 1:10) and leishmania chagasi antigen ( ...19911797267
acute renal failure in visceral leishmaniasis.we describe the case of a 33-year-old male patient with an acute visceral leishmaniasis (leishmania donovani) associated with an acute renal failure. the clinical manifestations were dominated by fever, oliguric renal failure and hepatic alterations. serum c3 and c4 fractions of complement were decreased, and a renal biopsy demonstrated an interstitial nephritis with no glomerular involvement. the clinical course was favorable with recuperation of renal function without sequels.19911799197
a case of lingual and palatine localization of a viscerotropic leishmania infantum zymodeme in sardinia, italy.an autochthonous case of leishmaniasis of tongue and palate is reported from sardinia, italy. the parasite isolated from the lingual lesion was typed through the electrophoretic analysis of 14 isoenzymes and it was identified as leishmania infantum zymodeme mon 27.19911801144
[cloning of the sequences of kinetoplast dna specific to leishmania donovani species and strains].to identify the heterogeneous dna sequences in the kinetoplast dna (kdna) minicircles, we digested the kdna from various species and isolates of leishmania into fragments with several restriction endonucleases and those fragments were southern hybridized with whole kdna. by this test, the alui fragments were shown to possess the species- and strain-specific sequences. we inserted these kdna (from l.d. sichuan human isolate) fragments into smai site of plasmid puc 18. the blunt ligation reaction ...19911802451
visceral leishmaniasis mimicking a flare of systemic lupus erythematosus.fever in systemic lupus erythematosus (sle) may be caused by exacerbation of the disease itself or by infection. we report on a patient with a long standing history of sle that was complicated by fever and pancytopenia with no splenomegaly. sle disease activity was suspected because of an elevated dna-antibody titer. the early positive response to corticoid therapy may have masked the underlying infection. visceral leishmaniasis was diagnosed by a repeated bone marrow biopsy and serological test ...19911802503
serodiagnosis of canine visceral leishmaniasis in portugal: comparison of three methods.sera collected in portugal from 43 dogs were screened for specific antibodies to leishmania donovani antigens. three different techniques were compared: an indirect immunofluorescence assay (ifa), a direct enzyme-linked immunosorbent assay (elisa) and a competitive-elisa (c-elisa) using two species-specific monoclonal antibodies, d2 and d13. by ifa, 22 of the sera examined showed positive reactions, compared with 26 by elisa or 27 by c-elisa. there was no direct correlation observed between the ...19911809243
role of hla-dr antigen on t-cell activation in visceral leishmaniasis.ability of peripheral blood monocytes in association with hla-dr molecules to support t-cell activation in response to soluble leishmania donovani antigen was investigated. adherent cells were stained with monoclonal antibodies. the increased number of cells with dr expression was more efficient in presenting l. donovani antigen to sensitized t-cells. the results suggest that quantitative variation in monocytes with expression of dr molecules, correlates with their ability to support t-cell resp ...19911816092
a novel leishmanicidal labdane from polyalthia macropoda.a new diterpene, (4s,9r,10r) methyl 18-carboxy-labda-8,13(e)-diene-15-oate has been obtained from the stem barks of polyalthia macropoda (annonaceae). this labdanic derivative was identified on the basis of spectroscopic data and is biologically active against the promastigote leishmania donovani donovani.19911818347
[ecoepidemiology of leishmaniases in syria. 2--presence, in dogs, of leishmania infantum nicolle and leishmania tropica (wright) (kinetoplastida-trypanonomatidae)].in an ecoepidemiological study in the syrian foci of human visceral (vl) and cutaneous (cl) leishmaniasis, domestic dogs infected with leishmania infantum mon-1 and l. tropica mon-76 were found for the first time. in syria canine leishmaniasis caused by l. infantum, occurs in the humid and sub-humid western belt from the coastal zone to the nearby mountain ranges. sporadis cases of human vl occur in this area. canine cl, caused by l. tropica was found in the semi-arid zone in a village with a hi ...19911822655
localization of the plasma membrane and mitochondrial h(+)-atpases in leishmania donovani promastigotes.immunochemical methods were used to characterize the proton-translocating atpases (h(+)-atpases) of the plasma membrane and mitochrondrion of leishmania donovani promastigotes. antisera directed against the plasma membrane h(+)-atpase of saccharomyces cerevisiae reacted with a 66 kda membrane protein of l. donovani promastigotes. by immunocytochemistry, the antiserum was shown to label the cell and flagellar surface of promastigotes as well as the golgi apparatus and the membrane of intracellula ...19911827766
conservation of cation-transporting atpase genes in leishmania.dna fragments isolated from leishmania donovani atpase genes were used to analyze the organization and expression of cation transporting atpase genes in l. donovani, leishmania tropica, leishmania mexicana, leishmania braziliensis, trypanosoma brucei and trypanosoma cruzi. the atpase loci in all leishmania species contained a tandem pair of atpase genes arranged in head-to-tail orientation and separated by approximately 2 kb. no restriction site polymorphisms were detected in the internal portio ...19911828863
developmental changes in the glycosylated phosphatidylinositols of leishmania donovani. characterization of the promastigote and amastigote glycolipids.in addition to utilizing glycosylated phosphatidylinositols (gpis) as anchors for surface proteins, protozoan parasites of the genus leishmania synthesize two novel classes of gpi: the polydisperse lipophosphoglycans (lpgs) and a family of low molecular weight glycoinositol phospholipids (gipls). we now show that lpg is expressed in high copy number (6 x 10(6) molecules/cell) in the promastigote (insect) stage of l. donovani but not in the amastigote stage, which infects mammalian macrophages. d ...19911831200
structure and transcription of a p-atpase gene from trypanosoma brucei.a putative atpase gene was cloned from trypanosoma brucei genomic dna. the length of the gene open reading frame is 3,033 bp, predicting a protein of about 110 kda. the sequence of this protein shares 10 blocks of homology with other eukaryotic atpases, including the putative phosphorylation site characteristic of p-atpases. its hydropathy profile reveals 8-10 potential membrane-spanning regions. while the amino acid sequence of the t. brucei atpase shows only 25% overall homology with its count ...19911833643
a sensitive repetitive dna probe that is specific to the leishmania donovani complex and its use as an epidemiological and diagnostic reagent.leishmania donovani (hu3 strain) metacyclic promastigotes generated in vitro were used to construct a cdna library in the bacteriophage vector lambda gt10. a cdna clone (lmet 2), was isolated by differential screening with metacyclic-derived or log-phase promastigote-derived cdna. the clone insert was comprised predominantly of four copies of an imperfect 60-bp repeat motif, which was represented in the genome by multiple tandem repeats distributed among at least six chromosomes. the correspondi ...19911840624
the scientific production of augusto corradetti in the field of medical entomology. 19911841204
methods of reducing ascogregarina chagasi parasitaemia in laboratory colonies of lutzomyia longipalpis.ascogregarina chagasi is an aseptate gregarine parasite found naturally in populations of lutzomyia longipalpis. under intensive rearing conditions in the laboratory, the parasite is known to reduce longevity and egg production, therefore, it is thought to be a major contributing factor to the phenomenon of colony crashes. a study is described to test egg cleansing techniques, with a view to controlling this parasite in laboratory colonies. methods used include washing eggs with formol, benzalko ...19911841206
the development of leishmania infantum in phlebotomus langeroni nitzulescu (diptera: psychodidae).the extrinsic development of leishmania infantum was observed in phlebotomus langeroni the potential vector of visceral leishmaniasis in el-agamy, egypt. flies were infected with l. infantum isolated from the same area, using membrane feeding technique. flies were examined for infection at 1-10 days post-infection. the initial establishment of the parasites was in the posterior midgut region beginning at sixth day post-infection. parasites were first observed in the esophagus at day 8, and in th ...19911841208
breeding places of phlebotomus argentipes annandale and brunetti (diptera: psychodidae) in west bengal, india.a search for the breeding places of phlebotomus argentipes annandale and brunetti was undertaken in west bengal during 1988-1990. sugar flotation technique was applied for the isolation of larvae from the collected soil samples and emergence trap and sticky paper trap were used for the collection of adults. soil incubation method was followed for the collection of emerged adults from the soil sample. a total 131 soil samples were analysed by flotation technique which produced 19 immature stages- ...19911841217
diapause and quiescence in lutzomyia diabolica (diptera:psychodidae).gravid, laboratory-reared lutzomyia diabolica from garner state park, texas, oviposited from may to december in an outdoor colony cage at gainesville, florida. egg batches contained 100% fast-developing (nondiapause) eggs, a mixture of fast-developing and slow-developing (diapause) eggs, or 100% slow-developing eggs, depending on the time of year laid. the percent diapause eggs per batch increased from 0% in early october to 100% by december. these observations suggest that lu. diabolica is a lo ...19911841227
a survey of phlebotomine sandflies (diptera: psychodidae) in hubei province, china.from june to august, 1987 a survey of phlebotomine sandflies was carried out by means of aspirator and light-sticky traps in nine counties viz., yunxi, wudangshan, snennongjia, zigui, yichang, lichuan, laifeng, hongan and yangxin, hubei province. a total of nine species had been identified: phlebotomus chinensis, p. kiangsuensis, p. mongolensis, sergentomyia anhuiensis, s. koloshanensis, s. nankingensis, s. squamirostris, s. zhengjiani and s. barraudi. their distribution was summarized in a map.19911841231
experimental infections of a phlebotomus perniciosus colony using different procedures.flies of two colonies of phlebotomus perniciosus established in italy and spain respectively, were infected with a leishmania infantum isolate from spain. only p. perniciosus from spain was completely found susceptible to the infection. experimental infections of p. perniciosus from spain with the same l. infantum isolate were carried out using rpmi or pbs as infective feeding mediums. the results demonstrate that using pbs it is possible to re-feed a great quantity of infected flies.19911841239
a review of investigations on leishmaniasis vectors in kenya.investigations on vectors of leishmaniases in kenya started only in the last 35 years when the visceral leishmaniasis assumed importance as a result of a major disease epidemic outbreak. since then detailed investigations on vectors of visceral leishmaniasis as well as vectors of newly found species causing cutaneous leishmaniasis have resulted in identification of their main vectors. synphlebotomus complex were shown to be the main vectors in kitui focus while in the other foci phlebotomus mart ...19911841244
the phlebotomine sandflies of portugal. v. observations on the ecology of the vectors of leishmaniasis in the alto douro region.in a survey carried out in the kala-azar endemic region of the alto douro, a total of 4,903 sandflies was caught, as follows: ph. ariasi 3,166 (64.6%), ph. perniciosus 1,533 (31.3%) and s. minuta 204 (4.1%). ph. ariasi was most abundant in september, when the greatest level of infection was observed (1.03%) while perniciosus was more abundant in july. in any case, both species coexist during great part of the year. no sandflies were found from november to april.19911841258
the sandflies of algeria.twenty-two species of sandflies are known to be present in algeria: 12 phlebotomus and 10 sergentomyia. each species has its own ecological distribution except in the mountains of the central sahara where both mediterranean species and species of the ethiopian zoo-geographical area occur together. phlebotomus perniciosus and p. papatasi are the proven vectors of leishmania infantum visceral leishmaniasis and l. major cutaneous leishmaniasis respectively.19911841261
differences between leishmania (leishmania) chagasi, l. (l.) infantum and l. (l.) donovani as shown by dna fingerprinting. 19911842444
in-vitro maintenance of leishmania donovani promastigotes in a cheap, serum-free, hemin-based, autoclavable culture medium. 19911842810
[entomological survey of sandflies (diptera, psychodidae) in the province of l'aquila (abruzzo)].a survey on phlebotomine sandflies (diptera, psychodidae) was carried out in the province of l'aquila, abruzzo region (italy). ten collecting sites at altitudes between 700 and 1,070 m a.s.l., produced a total of 324 specimens (81.1% males), 72.86% being phlebotomus perniciosus, 3.08% p. mascittii, 0.30% p. papatasi and 23.76% sergentomyia minuta. the collecting sites at 1,070, 950 and 775 m a.s.l. are the highest levels recorded in italy for p. perniciosus, p. mascittii and p. papatasi, respect ...19911844502
[effect of high temperature on promastigotes of 2 species of leishmania].a morphological and chemical transformation of the protozoon leishmania results during the shift from sand fly vector to mammalian host. this is due to the increase in temperature from about 26 degrees to about 35 degrees c. we evaluated the modifications induced by 37 degrees c on stationary phase promastigotes of two different leishmania species (l. major and l. infantum). l. infantum changed to amastigote-like forms in a greater and quicker way than l. major; this fact could relate with the m ...19911844918
a killing disease epidemic among displaced sudanese population identified as visceral leishmaniasis.a fatal disease epidemic affected the bentiu area in southern sudan and led to a mass migration of the nuer tribe searching for treatment. the initially available information revealed a high mortality rate due to a possible occurrence of tuberculosis, malaria, enteric fever or visceral leishmaniasis (vl). serological screening of 53 of the most severely affected patients in an enzyme-linked immunosorbent assay (elisa) or an improved direct agglutination test (dat) revealed positivity for vl. in ...19911852133
purification and characterization of a membrane-bound acid phosphatase of leishmania mexicana.as defined by the reaction with monoclonal antibodies, leishmania mexicana promastigotes contain two acid phosphatases which together comprise about 90% of the cellular activity. a first enzyme recognized by monoclonal antibody ap4 is largely membrane-bound. the protein has an apparent molecular weight of 70,000-72,000, carries about seven n-linked glycan chains and is present in approximately 16,000 copies per cell. the protein is also expressed in the amastigote stage. a second enzyme reactive ...19911857378
purification and characterization of the 3'-nucleotidase/nuclease from promastigotes of leishmania donovani.the surface membrane-associated 3'-nucleotidase/nuclease (3'-n'ase) of leishmania donovani has been purified from detergent extracted promastigotes by anion and cation exchange, lectin affinity and gel filtration chromatography. sds-page analysis of the purified enzyme preparation revealed a 43-kda polypeptide as well as faster migrating bands. these bands co-migrated, following both one- and two-dimensional electrophoretic analyses, with enzyme activity as determined by an in situ 3'-nucleotida ...19911857379
substrate-dependent ph optima of gp63 purified from seven strains of leishmania.the major surface glycoprotein of leishmania, gp63, is a membrane-bound metalloprotease. contradictory data supporting a neutral or acidic nature of this enzyme have been presented. seven strains of old and new world leishmania, including leishmania donovani complex (leishmania infantum and l. donovani), leishmania major, leishmania tropica and leishmania mexicana amazonensis were used for the purification and comparative study of gp63. the protein was extracted from promastigotes by phase separ ...19911857388
down-regulation of mannose receptors on macrophages after infection with leishmania donovani.macrophages express a mannose-specific endocytosis receptor that binds and internalizes mannose-terminated glycoproteins. infection of mouse peritoneal macrophages with leishmania donovani resulted in a decrease in mannose-receptor activity. with 125i-labelled beta-glucuronidase as ligand, a 2-fold decrease in uptake rate was observed in infected cells, with no change in kuptake. cell-surface binding of 125i-mannose-bsa was diminished 2.5-fold after infection. the decrease in ligand binding appe ...19911859373
antiprotozoal activity of 3'-deoxyinosine. inverse correlation to cleavage of the glycosidic bond.two nucleosides related to the known antiprotozoal agent 1-(beta-d-ribofuranosyl)-1,5-dihydro-4h-pyrazolo-[3,4-d]pyrimidine-4-one (allopurinol riboside, 1) were prepared and evaluated against leishmania donovani, trypanosoma cruzi, and trypanosoma gambiense. 3'-deoxyinosine (2) exhibited potent antiprotozoal activity against the three protozoal pathogens with minimal toxicity for host cells. it was found to be especially effective against the columbia strain of t. cruzi reported to be resistant ...19911859443
newly documented antimicrobial activity of quinolones.the improved antimicrobial activity of newer fluoroquinolones and novel applications recently found for the drugs already marketed are reviewed. several new compounds are more active against gram-positive bacteria than the presently marketed fluoroquinolones. win 57273, the most potent compound in vitro on a weight basis, is 16 to 128 times more active than ciprofloxacin against various staphylococci, streptococci, enterococcus spp., corynebacterium spp., listeria monocytogenes and bacillus spp. ...19911864284
malaria and leishmania parasites share the knob-associated histidine-rich protein gene sequences.1. the main coding region of the knob-associated histidine-rich protein (kahrp) gene of plasmodium falciparum hydridized with genomic dna of leishmania donovani. 2. a total of five ecori fragments of various sizes (7.5, 5.5, 3.2, 0.75 and 0.56 kb) were recognized by this probe, under lower stringent conditions. however, under a higher stringency of washing, two of the smallest fragments were washed away. 3. out of these ecori fragments, the 5.5 kb band showed a maximum homology with the probe wh ...19911868683
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