| ribavirin up-regulates il-12 p40 gene expression and restores il-12 levels in leishmania-treated pbmcs. | ribavirin, a nucleoside analogue that interferes with viral mrna synthesis and inhibits the replication of rna and dna viruses, has been recently proposed as an effective immune response modulator. in the present report, we studied the effect of ribavirin on il-12 p40 gene expression in peripheral blood mononuclear cells (pbmcs) of healthy subjects. we also studied ribavirin effects on pbmcs activated with lipopolysaccharide (lps) and phytohaemagglutinin (pha) and treated with leishmania donovan ... | 2005 | 16255743 |
| cloning and characterization of angiotensin converting enzyme related dipeptidylcarboxypeptidase from leishmania donovani. | we report the first identification, gene cloning, recombinant expression and biochemical characterization of an angiotensin converting enzyme (ace) related dipeptidylcarboxypeptidase (dcp) in a protozoan parasite. the mammalian counterpart of this enzyme, peptidyl dipeptidase a (a carboxyl dipeptidase) also known as ace leads to the cleavage of angiotensin i to produce a potent vasopressor. the catalytic enzyme activity of its escherichia coli dcp counter part can be inhibited by the antihyperte ... | 2006 | 16257064 |
| advances in leishmaniasis. | governed by parasite and host factors and immunoinflammatory responses, the clinical spectrum of leishmaniasis encompasses subclinical (inapparent), localised (skin lesions), and disseminated infection (cutaneous, mucosal, or visceral). symptomatic disease is subacute or chronic and diverse in presentation and outcome. clinical characteristics vary further by endemic region. despite t-cell-dependent immune responses, which produce asymptomatic and self-healing infection, or appropriate treatment ... | 2005 | 16257344 |
| visceral leishmaniasis (kala-azar)--the bihar (india) perspective. | from a hospital-based surveillance carried out in rajendra memorial research institute of medical sciences, patna, bihar, india, the socio-economic, demographic and treatment response information of 737 patients admitted with visceral leishmaniasis (vl) during january 2001-december 2003, were analysed. the disease was two times higher in males than in females because of several factors including clothing pattern, sleeping habits and occupation. in bihar, the second poorest state in india, povert ... | 2006 | 16269185 |
| homology-model-guided site-specific mutagenesis reveals the mechanisms of substrate binding and product-regulation of adenosine kinase from leishmania donovani. | despite designating catalytic roles of asp299 and arg131 during the transfer of gamma-phosphate from atp to ado (adenosine) [r. datta, das, sen, chakraborty, adak, mandal and a. k. datta (2005) biochem. j. 387, 591-600], the mechanisms that determine binding of substrate and cause product inhibition of adenosine kinase from leishmania donovani remained unclear. in the present study, employing homology-model-guided site-specific protein mutagenesis, we show that asp16 is indispensable, since its ... | 2006 | 16271040 |
| biomimetic synthesis, antimicrobial, antileishmanial and antimalarial activities of euglobals and their analogues. | in the present communication, naturally occurring phloroglucinol-monoterpene adducts, euglobals g1-g4 (3b/a and 4a/b) and 16 new analogues (13a/b-18a/b and 19-22) were synthesized by biomimetic approach. these synthetic compounds differ from natural euglobals in the nature of monoterpene and acyl functionality. all of these compounds were evaluated for their antibacterial, antifungal, antileishmanial and antimalarial activities. analogue 17b possessed good antibacterial activity against methicil ... | 2006 | 16274995 |
| irreversible inactivation of trypanothione reductase by unsaturated mannich bases: a divinyl ketone as key intermediate. | trypanothione reductase is a flavoenzyme unique to trypanosomatid parasites. here we show that unsaturated mannich bases irreversibly inactivate trypanothione reductase from trypanosoma cruzi, the causative agent of chagas' disease. the inhibitory potency of the compounds strongly increased upon storage of the dmso stock solutions. hplc, nmr, and mass spectrometry data of potential intermediates revealed a divinyl ketone as the active compound inactivating the enzyme. esi- and maldi-tof mass spe ... | 2005 | 16279799 |
| characterization of a methionine adenosyltransferase over-expressing strain in the trypanosomatid leishmania donovani. | methionine adenosyltransferase (mat: ec 2.5.1.6) catalyzes the synthesis of s-adenosylmethionine (adomet) in two sequential steps, adomet formation and subsequent tripolyphosphate (pppi) cleavage, induced by adomet. in pursuit of a better understanding of the biological function of the enzyme, the mat gene was cloned into vector px63neo to induce episomal overexpression in leishmania parasites. neomycin-selected clones originated a strain of such overexpressing parasites that accumulated more th ... | 2006 | 16280200 |
| a phase ii dose-increasing study of sitamaquine for the treatment of visceral leishmaniasis in kenya. | sitamaquine (wr6026) is an 8-aminoquinoline in development for the oral treatment of visceral leishmaniasis (vl). this was an open-label, dose-increasing study to determine the dose-response and safety profile for sitamaquine in kenyan patients with vl caused by leishmania donovani. patients (mean age 15.9 [range = 5-47] years) received sitamaquine daily for 28 days at one of four doses: 1.75 (n = 12), 2.0 (n = 61), 2.5 (n = 12), or 3.0 (n = 12) mg/kg/day. the primary efficacy outcome was cure ( ... | 2005 | 16282296 |
| identification and biochemical characterization of leishmania strains isolated in peru, mexico, and spain. | eight leishmania promastigotes were isolated from different geographical areas: three (lp1, lp2, and lp3) from the provincial department la libertad and the fourth (lp4) from the department of cajamarca (northern peru); another three (lm1, lm2, and lm3) in the province of campeche (mexico); and the last (ls1) from a clinical case of a dog in madrid (spain). the isolates were characterized by carbohydrate cell-surface residues using agglutinations with four purified lectins, by isoenzyme analysis ... | 2006 | 16289175 |
| prokaryotic expression, purification, and polyclonal antibody production against a novel drug resistance gene of leishmania donovani clinical isolate. | diseases produced by protozoan parasites are one of the main causes of morbidity and mortality around the world, affecting millions of people. among these, leishmaniasis has become the second most common cause of death and the problem is further complicated by the expansion of parasite resistance to the conventional drugs. the high rate of therapeutic failure thus calls for new rational approaches to develop alternative drugs. understanding resistance mechanisms may help identify new targets for ... | 2006 | 16289919 |
| leishmania donovani: differential activities of classical topoisomerase inhibitors and antileishmanials against parasite and host cells at the level of dna topoisomerase i and in cytotoxicity assays. | different classes of topoisomerase (top) inhibitors and antitrypanosomatid agents exhibited variable efficacies against leishmania donovani parasites and human mononuclear cells both at the level of dna topoisomerase i (topi) catalytic activity and in cytotoxicity assays. bis-benzimidazoles and the diamidine diminazene aceturate exhibited uniformly high efficacies against parasite and host enzymes as well as against parasite and mononuclear cells, but pentamidine showed around 2 orders of magnit ... | 2006 | 16293247 |
| acute fulminant visceral leishmaniasis in children--a report of two cases. | kala-azar usually presents in older children and young adults with insidious onset of fever, splenomegaly and pancytopenia. characteristic l.d. bodies in bone marrow or splenic aspirates are diagnostic of kala-azar. we report two cases of visceral leishmaniasis in children-1 1/2 and 10 year old with unusual presentation and fulminant course. in case 1 a female presented with fever, jaundice and bleeding manifestations. peripheral smear revealed l.d. bodies in neutrophils as well as monocytes. th ... | 2004 | 16295448 |
| amastigote forms of leishmania donovani in peripheral blood. | | 2004 | 16295510 |
| kala-azar at high altitude. | kala-azar or visceral leishmaniasis (vl) is a disease of low altitude (approximately 500 meters mean sea level). in india, however cases have been reported from sub-himalayan region (350-960 meters msl) of kumaon region of uttaranchal. we present two patients of vl, natives of tribal district of kinnnaur (2000-3000 meters msl), himachal pradesh, who had never visited known endemic area for leishmaniasis. these are probably first indigenous cases of vl being reported from an area situated at an a ... | 2004 | 16295673 |
| usefulness of the direct agglutination test in the early detection of subclinical leishmania donovani infection: a community-based study. | the value of a direct agglutination test (dat) in the detection of subclinical infections with leishmania donovani has recently been investigated in the indian state of bihar, after the sensitivity and specificity of the test had been determined. when used to screen sera from 108 parasitologically confirmed cases of visceral leishmaniasis, 50 patients with active, non-leishmanial infection, and 641 healthy controls living close to, or distant from, an endemic area, the test was found to be 91.7% ... | 2005 | 16297287 |
| chronic leishmania donovani infection promotes bystander cd8+-t-cell expansion and heterologous immunity. | it has been proposed that long-lived memory t cells generated by vaccination or infection reside within a memory compartment that has a finite size. consequently, in a variety of acute infection models interclonal competition has been shown to lead to attrition of preexisting memory cd8+ t cells. contrary to expectations, therefore, we found that chronic leishmania donovani infection of listeria-immune mice results in heightened protection against subsequent listeria challenge. this protection w ... | 2005 | 16299292 |
| regulation of impaired protein kinase c signaling by chemokines in murine macrophages during visceral leishmaniasis. | the protein kinase c (pkc) family regulates macrophage function involved in host defense against infection. in the case of leishmania donovani infection, the impairment of pkc-mediated signaling is one of the crucial events for the establishment of parasite into the macrophages. earlier reports established that c-c chemokines mediated protection against leishmaniasis via the generation of nitric oxide after 48 h. in this study, we investigated the role of mip-1alpha and mcp-1 in the regulation o ... | 2005 | 16299331 |
| efficacy of orally administered 2-substituted quinolines in experimental murine cutaneous and visceral leishmaniases. | we report in this study the in vivo efficacy of nine 2-substituted quinolines on the leishmania amazonensis cutaneous infection murine model and on the leishmania infantum and leishmania donovani visceral infection murine models. in the case of the l. amazonensis model, quinolines were administered orally at 25 mg/kg twice daily for 15 days. quinolines 1, 2, 3, and 7 reduced by 80 to 90% the parasite burdens in the lesion, whereas n-methylglucamine antimoniate (glucantime), administered by subcu ... | 2005 | 16304157 |
| report of an atypical case of leishmaniasis presented as acute tonsillitis in an immunocompetent patient. | visceral leishmaniasis typically presents with symptoms such as fever, enlargement of the spleen and the liver, hypergammaglobulinaemia and infection of the bone marrow resulting in anaemia and leukopenia. the disease is sporadic in the countries of the mediterranean basin. we report an unusual case of acute tonsillitis due to tonsillar leishmaniasis, in an immunocompetent 34-y-old male patient. diagnosis was confirmed by serological tests and histopathological examination following biopsy of th ... | 2005 | 16308231 |
| subclinical hypothyroidism in a patient affected by advanced aids and visceral leishmaniasis. | hypothyroidism has been shown to occur in hiv disease. thyroid function of patients affected by aids and leishmaniasis is unknown. here we report the case of an aids advanced patient developing hypothyroidism during leishmaniasis. the thyroid disorder might have been caused by infiltration of the gland by leishmania. an additive impact of hiv in thyroid function impairment is suggested. | 2005 | 16308238 |
| synthesis and antiprotozoal activity of some new synthetic substituted quinoxalines. | a series of 29 new quinoxalines was synthesized and evaluated in vitro against several parasites (leishmania donovani, trypanosoma brucei brucei, and trichomonas vaginalis). several of them displayed interesting activities, and particularly four quinoxaline amides showed in vitro antileishmanial properties (ic50 less than 20 microm). | 2006 | 16309903 |
| treatment options for visceral leishmaniasis: a systematic review of clinical studies done in india, 1980-2004. | the state of bihar in india carries the largest share of the world's burden of antimony-resistant visceral leishmaniasis. we analysed clinical studies done in bihar with different treatments between 1980 and 2004. overall, 53 studies were included (all but one published), of which 15 were comparative (randomised, quasi-randomised, or non-randomised), 23 dose-finding, and 15 non-comparative. data from comparative studies were pooled when appropriate for meta-analysis. overall, these studies enrol ... | 2005 | 16310148 |
| the sterol-binding antibiotic nystatin inhibits entry of non-opsonized leishmania donovani into macrophages. | leishmania donovani is an obligate intracellular parasite that infects macrophages of the vertebrate host resulting in visceral leishmaniasis in humans, a major public health problem worldwide. the molecular mechanisms involved in internalization of leishmania are still poorly characterized. we report here that cholesterol sequestration by the sterol-binding antifungal polyene antibiotic nystatin markedly inhibits binding and entry of non-opsonized l. donovani promastigotes into macrophages. int ... | 2006 | 16310160 |
| non pc liposome entrapped promastigote antigens elicit parasite specific cd8+ and cd4+ t-cell immune response and protect hamsters against visceral leishmaniasis. | leishmania donovani promastigote soluble antigens (slag) were encapsulated in non-phosphatidylcholine (non-pc) liposomes (escheriosomes) prepared from e. coli lipids. the escheriosome-based vaccine was investigated for its potential to elicit a protective immune response against experimental visceral leishmaniasis. the vaccine administration induced strong humoral as well as cell mediated immune responses both in hamsters and balb/c mice. immunization of balb/c mice with escheriosome entrapped s ... | 2006 | 16310900 |
| in vitro and ex vivo permissivity of hepatocytes for leishmania donovani. | using models of ex vivo infection of murine, rat, and human primary hepatocytes by leishmania donovani, we showed that hepatocytes are permissive for leishmania at a low level. we then modeled the in vitro infection of a human hepatoma-derived cell line to examine the parasite's capability to proliferate and to cause direct damage to hepatocytes. results showed that l. donovani can infect hepatocytes, but do not massively proliferate. this slight infection under our experimental conditions resul ... | 2005 | 16313440 |
| large-scale survey for potentially targetable indels in bacterial and protozoan proteins. | our previous results demonstrated that some essential, housekeeping proteins from pathogenic microorganisms may contain sizable insertions-deletions in their sequences (compared to close human homologs) that can be responsible for unexpected virulence properties. for example, we found that indel-bearing elongation factor-1alpha from several pathogenic protozoa can activate a human tyrosine phosphatase shp-1 leading to deactivation of macrophages. on the one hand, these findings allowed developme ... | 2006 | 16315289 |
| development of a semi-automated colorimetric assay for screening anti-leishmanial agents. | mts or {3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl}-2h-tetrazolium, inner salt) is converted into soluble formazan by mitochondrial dehydrogenase of viable cells, thus serving as an indicator of cell viability. accordingly, a mts-based assay was developed to evaluate anti-leishmanial activity in leishmania promastigotes from strains responsible for visceral, cutaneous or mucocutaneous leishmaniasis. the assay was initially optimized for the appropriate wavelength (4 ... | 2006 | 16316700 |
| treatment of visceral leishmaniasis. | the leishmania donovani complex includes l. chagasi and l. infantum, and causes visceral leishmaniasis (vl), a disseminated and potentially fatal form of leishmaniasis. the treatment options for vl are limited. pentavalent antimonials (sbv) are the first-line treatment options worldwide except for in europe and sbv-unresponsive regions of india. amphotericin b deoxycholate is the drug of choice in india, as are its lipid formulations in europe. however, liposomal amphotericin b (ambisome, gilead ... | 2005 | 16318433 |
| antileishmanial and trypanocidal activities of new miltefosine liposomal formulations. | liposomes composed of hexadecylphosphocholine/egg phosphatidylcholine/stearylamine (hepc/epc/sa) 10:10:0.1, 10:10:0.5 and 10:10:1 (molar ratio) (1-3) were prepared and lyophilized. the liposomes were physicochemically characterized (size and zeta-potential) and they were found stable at 4 degrees c over a period of 4 weeks. in vitro, liposomes 1 and 2 were about twice more active than hepc against leishmania donovani wt whereas liposomes 3 were about three times more active than hepc on hepc-res ... | 2005 | 16325367 |
| calcium-dependent proteolytic activity of a cysteine protease caldonopain is detected during leishmania infection. | a calcium-activated protease caldonopain in the cytosolic fraction of leishmania donovani has been found to digest different endogenous proteins when subjected to sds-page. gelatin-embedded gel electrophoresis confirms presence of calcium-dependent protease activity. ca(2+) affects proteolytic activity after 10 h. when host-parasite interaction was conducted in vitro, caldonopain was found to be active after 10 h of incubation with calcium. a 67-kda protein is specifically digested during this t ... | 2006 | 16328954 |
| antitrypanosomal, antileishmanial, and antimalarial activities of quaternary arylalkylammonium 2-amino-4-chlorophenyl phenyl sulfides, a new class of trypanothione reductase inhibitor, and of n-acyl derivatives of 2-amino-4-chlorophenyl phenyl sulfide. | quaternization of the nitrogen atom of 2-amino-4-chlorophenyl phenyl sulfide analogues of chlorpromazine improved inhibition approximately 40-fold (3',4'-dichlorobenzyl-[5-chloro-2-phenylsulfanyl-phenylamino)-propyl]-dimethylammonium chloride inhibited trypanothione reductase from trypanosoma cruzi with a linear competitive ki value of 1.7 +/- 0.2 microm). molecular modelling explained docking orientations and energies by: (i) involvement of the z-site hydrophobic pocket (roughly bounded by f396 ... | 2005 | 16335933 |
| sodium stibogluconate resistance in leishmania donovani correlates with greater tolerance to macrophage antileishmanial responses and trivalent antimony therapy. | co-treatment of mice infected with different strains of leishmania donovani with a non-ionic surfactant vesicle formulation of buthionine sulfoximine (bso-niv), and sodium stibogluconate (ssg), did not alter indicators of th1 or th2 responses but did result in a significant strain-independent up-regulation of il6 and nitrite levels by stimulated splenocytes from treated mice compared to controls. the efficacy of bso-niv/ssg treatment was dependent on the host being able to mount a respiratory bu ... | 2005 | 16336728 |
| application of an improved method for the recombinant k 39 enzyme-linked immunosorbent assay to detect visceral leishmaniasis disease and infection in bangladesh. | several serology-based immunoassays are used to diagnose visceral leishmaniasis (vl), a chronic protozoan parasitic disease caused by the leishmania donovani complex. these tests are primarily designed to diagnose the most severe clinical form of vl, known as kala-azar. however, leishmanial infection is frequently asymptomatic and may manifest only as a positive serologic response or positive leishmanin skin test. we modified a previously described enzyme-linked immunosorbent assay (elisa) that ... | 2005 | 16339064 |
| a triterpenoid saponin possessing antileishmanial activity from the leaves of careya arborea. | bioguided-fractionation of the methanol extract of the leaves of careya arborea led to isolation of a triterpenoid saponin, designated arborenin, and characterized as 3-o-beta-d-glucopyranosyl(1-->2)-beta-d-glucopyranosyl-2 alpha,3beta-dihydroxy-taraxast-20-en-28-oic acid (1), together with desacylescin iii (2). the structures were determined on the basis of extensive 2d nmr spectroscopic analysis. the saponin showed in vitro antileishmanial activity against leishmania donovani (strain ag 83). | 2006 | 16343564 |
| alkyl-linked bis-thtt derivatives as potent in vitro trypanocidal agents. | the effect of several alkyl-linked bis tetrahydro-(2h)-1,3,5-thiadiazine-2-thione (bis-thtt) on leishmania donovani, trypanosoma brucei rhodesiense, and plasmodium falciparum is reported. most of the compounds exhibited a potent activity against the three parasitic strains but the best in vitro activity profiles were found against t. b. rhodesiense with ic(50) values ranging between 0.3 and 4 microm for the most active compounds. | 2006 | 16343898 |
| value of culture and nested polymerase chain reaction of blood in the prediction of relapses in patients co-infected with leishmania and human immunodeficiency virus. | the use of culture and a nested polymerase chain reaction (pcr) of blood in predicting the probability of relapse was evaluated in 20 patients co-infected with leishmania and human immunodeficiency virus (hiv). fourteen of 20 patients relapsed, with 24 clinical relapses diagnosed. during clinical relapse, the parasite was detected by culture in 21 of 24 blood samples and by nested pcr in 23 of 24 blood samples. after treatment and during asymptomatic periods, the parasite was detected by culture ... | 2005 | 16354803 |
| syntheses of new substituted triazino tetrahydroisoquinolines and beta-carbolines as novel antileishmanial agents. | a series of triazino tetrahydroisoquinolines (3-5) and beta-carboline derivatives (15-27) have been synthesized as novel antileishmanial agents. among them, compounds 15, 16 and 25 have shown 78.0%, 78.6% and 68.0% in vivo inhibition against leishmania donovani at a dose of 50 mg kg(-1) x 5 days, respectively, while compounds 3 and 18 exhibited 55.6% and 53.3% in vivo inhibitions, respectively, against l. donovani at a dose of 50 mg kg(-1) x 5 days. | 2006 | 16356594 |
| adoptive immunotherapy against experimental visceral leishmaniasis with cd8+ t cells requires the presence of cognate antigen. | cd8+ t cells have a protective role in experimental visceral leishmaniasis. however, the observation that inflammatory cytokines induce bystander activation of cd8+ t cells questions the need for antigen-dependent effector function. here, we demonstrate that successful adoptive immunotherapy with cd8+ t cells is strictly dependent upon the presence of cognate antigen. | 2006 | 16369038 |
| rna interference reveals a role for tlr2 and tlr3 in the recognition of leishmania donovani promastigotes by interferon-gamma-primed macrophages. | leishmania donovani promastigotes evade the induction of a proinflammatory response during their invasion of naive macrophages. however, their entry into ifn-gamma-primed macrophages is accompanied by the secretion of nitric oxide (no) and proinflammatory cytokines. in the present study, we addressed the hypothesis that priming with ifn-gamma induces the expression of a receptor that enables mouse macrophages to recognize l. donovani promastigotes. we observed that in ifn-gamma-primed macrophage ... | 2006 | 16369915 |
| in vitro and in vivo interactions between miltefosine and other antileishmanial drugs. | the interaction of miltefosine with amphotericin b, sodium stibogluconate, paromomycin, and sitamaquine was assessed in vitro and additionally for the first three combinations in vivo. in vitro interactions were indifferent for miltefosine combined with amphotericin b (mean sums of fractional inhibitory concentrations [mean summation operatorfics] ranging from 1.22 to 1.51 at the 50% effective concentration [ec50] level and 1.08 to 1.38 at the ec90 level), sitamaquine (mean summation operatorfic ... | 2006 | 16377670 |
| resistance of leishmania donovani to sodium stibogluconate is related to the expression of host and parasite gamma-glutamylcysteine synthetase. | sequencing studies showed that the gamma-glutamylcysteine synthetase (gamma-gcs) heavy chain genes from sodium stibogluconate (ssg)-resistant (ssg-r) and ssg-susceptible (ssg-s) leishmania donovani strains were identical, indicating that ssg resistance was related to quantitative differences in gamma-gcs expression rather than gene interstrain polymorphisms. in vitro infection of murine macrophages with the ssg-r strain, but not the ssg-s strain, down regulated expression of host gamma-gcs, whic ... | 2006 | 16377672 |
| the fml-vaccine (leishmune) against canine visceral leishmaniasis: a transmission blocking vaccine. | transmission blocking vaccines are one of the control strategies for vector-transmitted protozoan diseases. antibodies raised in the vaccinated host prevent the development of the parasite in the insect vector, interrupting the epidemiological cycle. the fml antigen of leishmania donovani in combination with saponin (fml-vaccine and leishmune) induced 92-97% of protections against zoonotic visceral leishmaniasis. we assayed the ability of fml to inhibit leishmania donovani and leishmania chagasi ... | 2006 | 16386824 |
| the pathogenesis of post kala-azar dermal leishmaniasis from the field to the molecule: does ultraviolet light (uvb) radiation play a role? | post kala-azar dermal leishmaniasis (pkdl) is a dermatosis caused by persistence of leishmania donovani parasites in the skin following apparently successful treatment of visceral leishmaniasis. the distribution of pkdl lesions in sudanese patients often mirrors the clothing habits of those affected. it is most severe in or confined to the sun-exposed parts of the skin. it is well established that elimination of leishmania parasites requires activation of parasitised macrophages by a th1 immune ... | 2006 | 16386855 |
| reversal of adp-mediated aggregation of adenosine kinase by cyclophilin leads to its reactivation. | cyclophilins have been implicated in several important cellular functions. our earlier results showed that reactivation of adenosine kinase (adk) by cyp (ldcyp) from the parasitic protozoa leishmania donovani is accompanied with disaggregation of the enzyme [chakraborty, a., et al. (2002) j. biol. chem. 277, 47451-47460; chakraborty, a., et al. (2004) biochemistry 43, 11862-11872]. however, it remained to be known why the enzyme displayed progressive inhibition during the time-dependent reaction ... | 2006 | 16388602 |
| post-kala-azar dermal leishmaniasis: a histopathological study. | post-kala-azar dermal leishmaniasis follows an attack of visceral leishmaniasis and is caused by the same organism, i.e. leishmania donovani. | 2005 | 16394433 |
| interleukin-27r (wsx-1/t-cell cytokine receptor) gene-deficient mice display enhanced resistance to leishmania donovani infection but develop severe liver immunopathology. | the interleukin-27 (il-27)/t-cell cytokine receptor (tccr) pathway plays an important role in development of protective immunity against cutaneous leishmaniasis caused by leishmania major. in this study, we analyzed the role of il-27/tccr pathway in the host defense against visceral leishmaniasis (vl) by monitoring the course of l. donovani infection in tccr-deficient c57bl/6 (tccr-/-) mice. tccr-/- mice mounted a robust inflammatory response, produced high levels of pro-inflammatory cytokines, ... | 2006 | 16400019 |
| [the differential features of bone marrow morphology of several rare infectious disorders]. | to facilitate the diagnosis of histoplasmosis, kala-azar, penicilliosis marneffei, toxoplasmosis and cryptococcosis with the help of bone marrow morphology. | 2005 | 16409725 |
| risk factors for leishmania chagasi infection in an urban area of minas gerais state. | in order to understand the determinants of human infection by leishmania chagasi in an urban area, a cross-sectional population based study was conducted using molecular and serologic methods to identify infection. participants were interviewed using a pre-coded questionnaire. two criteria were tested to identify risk factors: model 1--including all participants positive in hybridization by leishmania donovani complex probe; model 2--including all participants positive for hybridization and at l ... | 2006 | 16410918 |
| identification of leishmania donovani antigens stimulating cellular immune responses in exposed immune individuals. | human visceral leishmaniasis (vl), also known as kala azar (ka) in india, is a systemic progressive disease caused by leishmania donovani. in vl, th1 responses correlate with recovery from and resistance to disease and resolution of infection results in lifelong immunity against the disease. however, recent data suggest an important role for interleukin (il)-10 in maintaining the resistant state. we evaluated whole cell extract (we) and 11 antigenic fractions [f1-f11, molecular weight (mw) range ... | 2006 | 16412064 |
| co-administration of il-12 dna with rorff antigen confers long-term protective immunity against experimental visceral leishmaniaisis. | visceral leishmaniasis, caused by the intracellular parasite leishmania donovani is a significant public health problem in many regions of the world. anti-leishmanial immune defences are primarily dependent on the ability of the host to mount an interleukin-12 (il-12) driven th1 type of responses. thus, il-12 plays a pivotal role in diversification of the immune responses towards th1 type. in this report, we investigated the effect of il-12 dna as an adjuvant with leishmanial recombinant open re ... | 2006 | 16413950 |
| c-reactive protein initiates transformation of leishmania donovani and l. mexicana through binding to lipophosphoglycan. | | 2006 | 16417933 |
| bioactive properties of plant species ingested by chimpanzees (pan troglodytes schweinfurthii) in the kibale national park, uganda. | we measured the biological activities of a selected sample (84 crude extracts) of 24 species eaten by wild chimpanzees (pan troglodytes schweinfurthii) in the kibale national park, western uganda, to assess their potential chemotherapeutic values. antibacterial, antimalarial, and/or antileishmania activities were observed in some crude extracts, and five of these extracts showed a significant cytotoxicity against human tumor cells. active compounds isolated from three plant parts occasionally in ... | 2006 | 16419122 |
| antileishmanial and trypanocidal activity of brazilian cerrado plants. | the side effects and the emerging resistance to the available drugs against leishmaniasis and trypanosomiasis led to the urgent need for new therapeutic agents against these diseases. thirty one extracts of thirteen medicinal plants from the brazilian cerrado were therefore evaluated in vitro for their antiprotozoal activity against promastigotes of leishmania donovani, and amastigotes of trypanosoma cruzi. among the selected plants, casearia sylvestris var. lingua was the most active against bo ... | 2005 | 16419337 |
| genetics of murine leishmaniasis. | leishmaniasis encompasses a number of disease syndromes, caused by several species of the digenetic protozoan leishmania, and is transmitted by sandflies. the mouse model of the disease has been used to identify genes involved in disease susceptibility--for example, the slc11a1 gene, important in resistance to leishmania donovani--and to map loci important in leishmania major infection. the genetics of the host response to l. major has been shown to be complex and to involve much more than the t ... | 2005 | 16420752 |
| comparative antiplasmodial, leishmanicidal and antitrypanosomal activities of several biflavonoids. | the antiplasmodial, leishmanicidal and antitrypanosomal activities of eight natural biflavonoids were estimated in vitro on a chloroquine-resistant strain of plasmodium falciparum, axenically grown leishmania donovani amastigotes and trypanosoma cruzi trypomastigotes and trypanosoma brucei rhodesiense bloodstream forms. lanaroflavone showed the highest antiplasmodial activity (ic(50) = 0.48 microm), isoginkgetin was the most active leishmanicidal compound (ic(50) = 1.9 microm), whereas ginkgetin ... | 2006 | 16428025 |
| new diseases and increased risk of diseases in companion animals and horses due to transport. | dogs and horses are transported within the european union for a number of reasons. the transport per se may cause physical problems, exemplified by hyperthermia in dogs and pleuropneumonia in horses, and the stress may reactivate latent infections such as canine herpesvirus-1 and equine herpesvirus-1. preventive treatments are vital to protect dogs from ticks and mosquitoes transmitting their potentially lethal infectious agents, such as leishmania donovani infantum, babesia canis, ehrlichia can ... | 2003 | 16429803 |
| pathogen inactivation of leishmania donovani infantum in plasma and platelet concentrates using riboflavin and ultraviolet light. | leishmania is transmitted by the bite of the phlebotomine sandfly or by transfusion of infected blood products. leishmaniasis currently poses a significant problem in several parts of the world, and is an emerging problem in others. the mirasol prt technology is based on the use of riboflavin and ultraviolet light to generate chemical reactions in the nucleic acids of pathogens, which prevents replication and leads to inactivation. the intent of this study was to examine the ability of the miras ... | 2006 | 16430665 |
| antimony-induced cerebellar ataxia. | visceral leishmaniasis vl, caused by leishmania donovani is endemic over several parts of sudan. the disease is fatal if not treated. although sodium stibogluconate pentostam, a pentavalent antimonial is not free from toxicity, it has been in use for treatment of vl for the last 50 years. like other infectious diseases, neurological manifestations of vl and sodium stibogluconate have been documented. in this report, we present 2 cases of cerebellar ataxia most likely induced by pentostam, and ex ... | 2006 | 16432602 |
| acyclic pyrazolo[3,4-d]pyrimidine nucleoside as potential leishmaniostatic agent. | a new synthesis of 6-amino-1-hydroxyethoxymethyl-4 (5h)-oxopyrazolo[3, 4-d]pyrimidine (4) has been mentioned. compound 4 exhibited inhibition of amastigotes of leishmania donovani to the extent of 89 % at 30 microg/ml, whereas iso-guanine analogue 5 had the inhibition only to the extent of 52.8% at 100 microg/ml in vitro. in hamster model the maximum inhibitory response for compound 4 against amastigotes multiplication was observed to be 94% at 50 mg/kg single dose for 5 consecutive days. | 2006 | 16440985 |
| isoflavonoids and other compounds from psorothamnus arborescens with antiprotozoal activities. | bioactivity-guided fractionation of the root extract of psorothamnus arborescens yielded the new isoflavone 5,7,3',4'-tetrahydroxy-2'-(3,3-dimethylallyl)isoflavone (1a) and the new 2-arylbenzofuran 2-(2'-hydroxy-4',5'-methylenedioxyphenyl)-6-methoxybenzofuran-3-carbaldehyde (2), together with seven known compounds, including three isoflavones, fremontin (3a), glycyrrhisoflavone (4a), and calycosin (5), two pterocarpans, maackiain (6) and 4-hydroxymaackiain (7), one triterpene, oleanolic acid (8) ... | 2006 | 16441066 |
| evaluation of ifn-gamma production by cd8 t lymphocytes in response to the k1 peptide from kmp-11 protein in patients infected with trypanosoma cruzi. | the cellular response mediated by mhc class i restricted cd8+ t cells has been shown to be crucial in the control of chagas disease. the k1 peptide derived from t. cruzi kmp-11 protein has a high binding affinity to the hla-a*0201 molecule. nevertheless, it is not known whether this peptide is processed and displayed as an mhc class i epitope during natural infection by t. cruzi. the aim of this study was to evaluate, by elispot assay, the ability of k1 peptide to activate cd8+ t lymphocytes to ... | 2006 | 16441508 |
| a cooh-terminal domain regulates the activity of leishmania proton pumps ldh1a and ldh1b. | leishmania donovani requires actively transporting proton efflux pumps to survive the acidic environment of macrophage phagolysosomal vacuoles and to maintain an electrogenic h(+) gradient for nutrient uptake. the l. donovani genome contains a differentially expressed pair of genes, ldh1a and ldh1b, with homology to yeast h(+)-atpases that are 98% identical in sequence with amino acid differences concentrated at the cooh-terminus (15 of last 37 differ), a region implicated in regulation of yeast ... | 2006 | 16442543 |
| lutzomyia longipalpis and the eco-epidemiology of american visceral leishmaniasis, with particular reference to brazil: a review. | an historical review is given of american visceral leishmaniasis (avl), with particular reference to the eco-epidemiology of the disease in brazil. following the first records of avl in this country, in 1934, the sandfly lutzomyia longipalpis (lutz and neiva, 1912) was incriminated as the principal vector. it is now generally accepted, however, that there exist a number of cryptic species under the name of lu. longipalpis s.l. and that variations in the quantity of the vasodilatory peptide maxad ... | 2006 | 16444411 |
| canine visceral leishmaniosis: a comparative analysis of the eie-leishmaniose-visceral-canina-bio-manguinhos and the ifi-leishmaniose-visceral-canina-bio-manguinhos kits. | this study evaluated the performance of the eie-leishmaniose-visceral-canina-bio-manguinhos (eie-lvc) kit and to compare it with that of the ifi-leishmaniose-visceral-canina-bio-manguinhos (ifi-lvc) kit. four groups of dogs were studied: group 1 (g1), dogs with clinical signs indicative of cvl and testing positive for the parasite (n = 25); group 2 (g2), dogs with only a presumed diagnosis of cvl (n = 62); group 3 (g3), dogs that had never lived in an area where cvl is endemic and never received ... | 2006 | 16446034 |
| leishmania donovani: identification of stimulatory soluble antigenic proteins using cured human and hamster lymphocytes for their prophylactic potential against visceral leishmaniasis. | most of the studies for the identification of prophylactic antigens that elicit t cell responses were concentrated on membrane proteins of leishmania donovani. this study was taken up to assess l. donovani soluble promastigote antigens for their ability to stimulate proliferation of peripheral blood mononuclear cells (pbmcs) from cured visceral leishmaniasis (vl) patients, endemic and non-endemic controls and lymphocytes/peritoneal macrophages of cured hamsters. the soluble protein was subjected ... | 2006 | 16448729 |
| multilocus microsatellite typing as a new tool for discrimination of leishmania infantum mon-1 strains. | the leishmania donovani complex, which consists of l. donovani, l. infantum-l. chagasi, and l. archibaldi, is responsible for visceral manifestations of leishmaniasis. multilocus enzyme electrophoresis is the standard method for the characterization and identification of strains of leishmania. for l. infantum, the predominance of zymodeme mon-1 significantly reduces the discriminative power of this approach. in the present study, we developed 17 independent polymorphic microsatellite markers for ... | 2006 | 16455904 |
| first report on the presence of morphospecies a and b of phlebotomus argentipes sensu lato (diptera: psychodidae) in sri lanka--implications for leishmaniasis transmission. | | 2005 | 16457386 |
| refinement of techniques for the propagation of leishmania donovani in hamsters. | improved animal models are urgently required for drug and vaccine development against visceral leishmaniasis. here we report refinements to the hamster model of infection that reduce the severity of the disease as well as the number of animals required to maintain infection while improving parasite yields. a comparison between infection via the intracardiac and intraperitoneal routes showed that the less commonly used intraperitoneal route is the simpler and preferred method. the katex latex agg ... | 2006 | 16464432 |
| point mutations within the ldnt2 nucleoside transporter gene from leishmania donovani confer drug resistance and transport deficiency. | leishmania donovani, a protozoan parasite, expresses an unusual inosine/guanosine-specific transporter, ldnt2, the gene for which was cloned by functional rescue of a drug-resistant, ldnt2-deficient (fbd5) strain. in this investigation, we have uncovered and characterized the mutations within the ldnt2 open reading frame that are the basis for the drug-resistance and transport-incompetent phenotype of the fbd5 line. the fbd5 cells were shown to be compound heterozygotes in which both mutant ldnt ... | 2006 | 16464630 |
| [management of cutaneous leishmaniasis in adults and children]. | cutaneous leishmaniasis can present a variety of clinical features and courses. the causative leishmania species is an important prognostic factor in immunocompetent patients. local treatment modalities including topical paromomycin, cryotherapy, localized controlled heat, carbon dioxide laser therapy, or intralesional meglumine antimoniate can be effective against leishmania major or leishmania tropica. oral fluconazole may be a second-line treatment. parenteral antimonials are useful for persi ... | 2005 | 16465821 |
| upregulation of surface proteins in leishmania donovani isolated from patients of post kala-azar dermal leishmaniasis. | five to fifteen percent of visceral leishmaniasis (vl) patients in india develop post kala-azar dermal leishmaniasis (pkdl), usually 1-2 years after apparent clinical cure. there is evidence pointing to a role played by the host immune responses in the disease pathogenesis, however, the contribution of changes in parasite gene expression has not been explored. highly sensitive gene expression microarray technology was employed to identify genes that are differentially expressed in leishmania par ... | 2006 | 16469521 |
| leishmania tropica-isolated patient with visceral leishmaniasis in southern iran. | visceral leishmaniasis (vl) is caused by various strains of leishmania donovani, leishmania infantum, and leishmania chagasi with different geographical distribution. the aim of this study was to identify the strains of leishmania that can cause vl in southern iran. dna of leishmania were extracted from the slides of bone marrow aspirates (#42) and spleen punctures (#22), which were positive for leishman body from the patients who were referred to the hospitals affiliated with shiraz university ... | 2006 | 16474088 |
| spatial clustering and epidemiological aspects of visceral leishmaniasis in two endemic villages, baringo district, kenya. | visceral leishmaniasis (vl) seroprevalence in kenya is unknown because of the lack of a practical and accurate diagnostic test or surveillance system. a novel serological assay was used to estimate the seroprevalence of leishmania-specific antibodies, and global information system and spatial clustering techniques were applied to study the presence of spatial clusters in parkarin and loboi villages in baringo district in 2001. vl seroprevalences were 52.5% in parkarin and 16.9% in loboi. signifi ... | 2006 | 16474089 |
| hfip-induced structures and assemblies of the peptides from the transmembrane domain 4 of membrane protein nramp1. | membrane protein nramp1 (natural resistance-associated macrophage protein 1) is a ph-dependent divalent metal cation transporter that regulates macrophage activation in infectious and autoimmune diseases. a naturally occurring glycine to aspartic acid substitution at position 169 (g169d) within the transmembrane domain 4 (tm4) of nramp1 makes mice susceptible to leishmania donovani, salmonella typhimurium, and mycobacterium bovis. here we present a structural and self-assembling study on two syn ... | 2006 | 16479587 |
| isolated laryngeal leishmaniasis in an immunocompetent patient in india. | | 2006 | 16483442 |
| leishmania donovani cyclin 1 (ldcyc1) forms a complex with cell cycle kinase subunit crk3 (ldcrk3) and is possibly involved in s-phase-related activities. | expression of leishmania donovani cyclin 1 (ldcyc1) mrna during the cell cycle of promastigotes is s-phase specific. here, we show that the ldcyc1 protein is periodically expressed and the activity of its associated kinase varies during the cell cycle in line with its expression pattern. in addition, we have shown that ldcrk3, homologous to crk3 from l. mexicana, is the cognate cdk partner of ldcyc1 and that the activity of the complex is inhibited specifically by heat stable factor(s) from the ... | 2006 | 16487322 |
| the structure of the transition state of the heterodimeric topoisomerase i of leishmania donovani as a vanadate complex with nicked dna. | type ib topoisomerases are essential enzymes that are responsible for relaxing superhelical tension in dna by forming a transient covalent nick in one strand of the dna duplex. topoisomerase i is a target for anti-cancer drugs such as camptothecin, and these drugs also target the topoisomerases i in pathogenic trypanosomes including leishmania species and trypanosoma brucei. most eukaryotic enzymes, including human topoisomerase i, are monomeric. however, for leishmania donovani, the dna-binding ... | 2006 | 16487540 |
| differential induction of leishmania donovani bi-subunit topoisomerase i-dna cleavage complex by selected flavones and camptothecin: activity of flavones against camptothecin-resistant topoisomerase i. | emergence of the bi-subunit topoisomerase i in the kinetoplastid family (trypanosoma and leishmania) has brought a new twist in topoisomerase research related to evolution, functional conservation and preferential sensitivities to the specific inhibitors of type ib topoisomerase family. in the present study, we describe that naturally occurring flavones baicalein, luteolin and quercetin are potent inhibitors of the recombinant leishmania donovani topoisomerase i. these compounds bind to the free ... | 2006 | 16488884 |
| long-term preservation of leishmania donovani promastigotes on blood-agar slants. | | 2006 | 16492365 |
| glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of leishmania spp. against nitrosothiol-induced cytotoxicity. | glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. in trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. although kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. the aim of this ... | 2006 | 16501815 |
| arylanthranilodinitriles: a new biaryl class of antileishmanial agents. | a series of anthranilodinitrile-based biaryls were synthesized and evaluated in vitro against extracellular promastigotes and intracellular amastigotes of leishmania donovani. among various screened compounds, a biaryl with trifluoromethyl group 5f showed 83% inhibition against promastigotes and 70% inhibition against amastigotes of l. donovani at 8 and 20microg/ml concentrations, respectively. | 2006 | 16503140 |
| regulation of guanylyl cyclase by intracellular ca2+ in relation to the infectivity of the protozoan parasite, leishmania donovani. | a neuronal type ca2+ stimulated nitric oxide synthase was earlier reported by us to be present in the protozoan parasite leishmania donovani. as part of nitric oxide-cyclic gmp transduction signaling operative in higher eukaryotes and involved in the long-term potentiation, a soluble guanylyl cyclase has also been detected in this lower eukaryote. however, detailed biochemical characterization revealed the enzyme to be ca2+ modulated and unstimulated by nitric oxide donors as opposed to higher e ... | 2006 | 16507348 |
| identification of novel parasitic cysteine protease inhibitors by use of virtual screening. 2. the available chemical directory. | the incidence of parasitic infections such as malaria, leishmaniasis, and trypanosomiasis has been steadily increasing. since the existing chemotherapy of these diseases suffers from lack of safe and effective drugs and/or the presence of widespread drug resistance, there is an urgent need for development of potent, mechanism-based antiparasitic agents against these diseases. cysteine proteases have been established as valid targets for this purpose. the available chemical directory consisting o ... | 2006 | 16509575 |
| an intracellular calcium store is present in leishmania donovani glycosomes. | a fourth intracellular ca2+ pool in leishmania donovani was identified by permeabilizing plasma membrane with digitonin. in fura 2 loaded cells ca2+ was released synergistically when mitochondrial function was blocked by antimycin and oligomycin. vanadate did not have any effect if applied before incorporation of these mitochondrial poisons. however, the same inhibitor which inhibits ca2+-atpase activity of endoplasmic reticulum was able to release ca2+ at a slow rate when added after antimycin ... | 2006 | 16513112 |
| rapid & reliable diagnostic tests for visceral leishmaniasis. | | 2005 | 16517995 |
| transfusion medicine illustrated. electron micrographic study of the removal of leishmania from blood products by leukodepletion filters. | | 2006 | 16533268 |
| molecular characterization of a human brca2 homolog in leishmania donovani. | the breast cancer susceptibility protein brca2 is implicated in the dna double-strand break (dsb) repair pathway through its association with rad51. it is almost a ubiquitous eukaryotic protein; homologs of the brca2 gene (brh2) have been identified in many mammals, as well as nonmammals. as a part of our quest to understand the dna damage, repair, and recombination process in the parasitic protozoan, leishmania sp., we have cloned and characterized a brca2 homolog from leishmania sp. (lbrh2). l ... | 2005 | 16539040 |
| testosterone attenuates p38 mapk pathway during leishmania donovani infection of macrophages. | leishmania donovani (l. donovani) is an obligatory intracellular pathogen that resides and multiplies in the macrophages and has been found to alter the signaling parameters of the host. testosterone plays a key role as signaling molecules in the regulation of parasite infections and could increase l. donovani infection of macrophages. the mitogen-activated protein kinases (mapks) pathway participates in the regulation of functions involved in parasite infection and host defense. in this work, t ... | 2006 | 16547729 |
| visceral leishmania donovani infection in interleukin-13-/- mice. | leishmania donovani-infected interleukin-13-/- balb/c mice showed impaired initial gamma interferon secretion and incomplete granuloma assembly at parasitized liver foci. nonetheless, control of early parasite replication, resolution of liver infection, and responsiveness to antileishmanial chemotherapy were intact. by itself, interleukin-13 does not appear to materially influence acquired resistance in this intracellular infection. | 2006 | 16552085 |
| a novel high-affinity arginine transporter from the human parasitic protozoan leishmania donovani. | we describe the first functional and molecular characterization of an amino acid permease (ldaap3) from the human parasitic protozoan leishmania donovani, the causative agent of visceral leishmaniasis in humans. this permease contains 480 amino acids with 11 predicted trans-membrane domains. expressing ldaap3 in saccharomyces cerevisiae mutants revealed that ldaap3 codes for a high-affinity arginine transporter (km 1.9 microm). ldaap3 is highly specific for arginine as its transport was not inhi ... | 2006 | 16556218 |
| acylated and deacylated saponins of quillaja saponaria mixture as adjuvants for the fml-vaccine against visceral leishmaniasis. | the adjuvant of the fml-vaccine against murine and canine visceral leishmaniasis, the riedel de haen saponin mixture, was fractionated by ion exchange chromatography on deae-cellulose to afford one tlc homogeneous quillaja saponaria molina qs21 saponin fraction (18.0%), a mixture of two deacylsaponins (19.4%), sucrose (39.9%), sucrose and glucose (19.7%), rutin (0.8%) and quercetin (2.2%), that were identified by comparison of 1h and 13c nmr spectroscopy. the qs21 shows the typical aldehyde grou ... | 2006 | 16556475 |
| effect of natural l- to d-amino acid conversion on the organization, membrane binding, and biological function of the antimicrobial peptides bombinins h. | antimicrobial peptides (amps) are evolutionarily old components of innate immunity found in all living pluricellular organisms. interestingly, some organisms express families of amps with only a slight variation among their members, possibly to increase their spectrum of activity. despite the growing body of knowledge about their biological activity and mode of action on bacteria, only a few of them have been tested on leishmania, a worldwide spread protozoan pathogen, and the parameters contrib ... | 2006 | 16566601 |
| antitrypanosomal and antileishmanial activities of flavonoids and their analogues: in vitro, in vivo, structure-activity relationship, and quantitative structure-activity relationship studies. | trypanosomiasis and leishmaniasis are important parasitic diseases affecting millions of people in africa, asia, and south america. in a previous study, we identified several flavonoid glycosides as antiprotozoal principles from a turkish plant. here we surveyed a large set of flavonoid aglycones and glycosides, as well as a panel of other related compounds of phenolic and phenylpropanoid nature, for their in vitro activities against trypanosoma brucei rhodesiense, trypanosoma cruzi, and leishma ... | 2006 | 16569852 |
| treatment options for visceral leishmaniasis. | this review summarizes the current developments in therapy for visceral leishmaniasis. with the recent introduction of new drugs, the main limits in reducing deaths from visceral leishmaniasis are difficulty in diagnosis in the field and health inequality--patients lack of access to treatment. no new drugs are currently in the early stages of development. there are good reasons for the use of combination therapy; to prevent further development of resistance against the limited therapeutic option ... | 2006 | 16597201 |
| leishmania donovani singly deficient in hgprt, aprt or xprt are viable in vitro and within mammalian macrophages. | leishmania species express three phosphoribosyltransferase enzymes, hypoxanthine-guanine phosphoribosyltransferase (hgprt), adenine phosphoribosyltransferase (aprt), and xanthine phosphoribosyltransferase (xprt), which enable this genus to acquire purine nutrients from their hosts. to test whether any of these enzymes is essential for viability, transformation into amastigotes, and infectivity and proliferation within mammalian macrophages, deltahgprt, deltaaprt, and deltaxprt null mutants were ... | 2006 | 16597468 |
| clinical presentation and management of visceral leishmaniasis. | febrile illnesses like malaria, typhoid, and tuberculosis are the commonest problems in our area, but visceral leishmaniasis (vl) is also one of the diseases presenting with fever in this part of the country. this study was conducted to evaluate its clinical spectrum and way of management. | 2005 | 16599036 |
| a conditional mutant deficient in hypoxanthine-guanine phosphoribosyltransferase and xanthine phosphoribosyltransferase validates the purine salvage pathway of leishmania donovani. | leishmania donovani cannot synthesize purines de novo and express a multiplicity of enzymes that enable them to salvage purines from their hosts. previous efforts to generate an l. donovani strain deficient in both hypoxanthine-guanine phosphoribosyl-transferase (hgprt) and xanthine phosphoribosyltransferase (xprt) using gene replacement approaches were not successful, lending indirect support to the hypothesis that either hgprt or xprt is crucial for purine salvage by the parasite. we now repor ... | 2006 | 16603734 |
| leishmania donovani: effect of verapamil on in vitro susceptibility of promastigote and amastigote stages of indian clinical isolates to sodium stibogluconate. | although pentavalent antimonials are the first-line drug for treatment of visceral leishmaniasis all over the world, yet, in india, increasing number of patients are being reported to be unresponsive to sodium stibogluconate. verapamil, a calcium channel blocker, affects drug uptake by preventing its efflux and thereby accumulation within the cell. in the present study, effect of verapamil on in vitro susceptibility of both promastigote and amastigote stages of 15 clinical isolates and standard ... | 2006 | 16616137 |
| seroepidemiological survey on canine leishmaniasis among dogs from an urban area of brazil. | a cross-sectional seroepidemiological survey on canine leishmaniasis among pet dogs was carried out in an urban area in the state of pernambuco (brazil) where human cases of visceral leishmaniasis have sporadically been reported. using an indirect fluorescent antibody test, anti-leishmania antibodies were detected in 130 out of 322 dogs, confirming previous exposure to leishmania parasites. the overall seroprevalence found was 40.3% (95% confidence interval: 34.9-45.9). data analysis revealed th ... | 2006 | 16621286 |