| leishmania amazonensis: uptake and hydrolysis of 3h-amino acid methyl esters by isolated amastigotes. | intracellular and isolated amastigotes of leishmania amazonensis can be destroyed by l-amino acid methyl esters known to disrupt mammalian lysosomes. to evaluate the mechanism(s) involved in the leishmanicidal activity, we examined the uptake and hydrolysis of tritiated esters by isolated amastigotes. after incubation with the labeled compounds, parasites were recovered, were washed on filters, and their radioactivity was determined. alternatively, amastigotes were separated from the medium by c ... | 1989 | 2924877 |
| tunicamycin-resistant leishmania mexicana amazonensis: expression of virulence associated with an increased activity of n-acetylglucosaminyltransferase and amplification of its presumptive gene. | tunicamycin at 10 micrograms/ml inhibits the growth and infectivity of the parasitic protozoan leishmania mexicana amazonensis. tunicamycin-resistant variants of this parasite were produced by gradual acclimatization of cells to increasing concentrations of the drug up to 80 micrograms/ml and a single-step selection of ethyl methanesulfonate-pretreated or differentiating leishmanias with the drug at 10 micrograms/ml. prolonged exposure to the drug increases stability of drug resistance of those ... | 1987 | 2950522 |
| involvement of the macrophage mannose-6-phosphate receptor in the recognition of leishmania mexicana amazonensis. | significant differences were found in the ability of resident mouse peritoneal macrophages to ingest amastigote and promastigote forms of leishmania mexicana amazonensis. differences in the association index of the parasites to the macrophages were also found between infective and non-infective promastigotes. evidence was obtained suggesting that the macrophage receptor, which recognizes mannose-6-phosphate-containing units found in lysosomal enzymes, is involved in the association with the macr ... | 1987 | 2958844 |
| pathophysiology of experimental leishmaniasis: the role of parasite physiology in the development of metastatic disease. | this paper addresses the issue of how physiological properties of leishmania determine the pattern of development of disseminated leishmaniasis in the mammalian host. it presents direct experimental evidence from in vivo studies that species of leishmania differ in their capacity to multiply in cutaneous and visceral sites which results in differences in the pattern and rate of development of leishmaniasis. it was found that leishmania mexicana amazonensis begins to multiply in the cutaneous sit ... | 1988 | 2972218 |
| kinetoplast dna minicircles: regions of extensive sequence divergence. | previous work has shown that the kinetoplast minicircle dna of leishmania species exhibits species-specific sequence divergence and this observation has led to the development of a dna probe-based diagnostic test for leishmaniasis. in the work reported here, we demonstrate that the minicircle is composed of three types of dna sequences with differing specificities reflecting different rates of dna sequence change. a library of cloned fragments of kinetoplast dna (kdna) from leishmania mexicana a ... | 1987 | 3025880 |
| biological and biochemical characterization of tunicamycin-resistant leishmania mexicana: mechanism of drug resistance and virulence. | a parasitic protozoan, leishmania mexicana amazonensis, was previously made resistant to tunicamycin (j.a. kink and k.-p. chang, proc. natl. acad. sci. usa 84:1253-1257, 1987). in the present study, six different tunicamycin-resistant variants were biologically and biochemically compared with their parental wild type to further delineate the mechanism of tunicamycin resistance and that of their virulence observed. in contrast to their parental wild type, all tunicamycin-resistant variants were f ... | 1987 | 3036710 |
| leishmania amazonensis: acidic organelles in amastigotes. | leishmania amastigotes are intracellular protozoan parasites which exclusively invade cells of the macrophage series and multiply within phagolysosomes. recent studies showed that intracellular and isolated amastigotes of l. amazonesis are killed by amino acid esters which appear to be trapped within as yet unidentified, possibly acidified, "lysosome-like" parasite compartments and cleaved by hydrolytic enzyme(s) (m. rabinovitch, v. zilberfarb, and c. ramazeilles, 1986, journal of experimental m ... | 1988 | 3056736 |
| the role of hematopoietic growth factors in the fate of an infection with leishmania mexicana amazonensis: an attempt at a unifying hypothesis. | | 1988 | 3075684 |
| monoclonal antibody affinity purification of a leishmania membrane glycoprotein and its inhibition of leishmania-macrophage binding. | specific monoclonal antibody coupled to affi-gel 10 was used to purify a major membrane glycoprotein of leishmania mexicana amazonensis, one of a group of parasitic protozoa that specifically infect mammalian macrophages. immobilized antigen was eluted at a 34% efficiency with buffers at either ph 2.5 or 11 or with mgcl2, but only the antigen eluted under basic conditions could be readsorbed to the immunobeads. sephacryl s-300 gel filtration of the purified antigen gave a single peak of protein ... | 1986 | 3079902 |
| leishmania mexicana amazonensis: adp-ribosyltransferase antagonists specifically inhibit amastigote to promastigote differentiation. | leishmania mexicana amazonensis amastigotes were induced to differentiate by incubation at 27 c. morphological transformation was studied both in untreated cultures and in cultures where dna synthesis, and consequently the final stage in the production of promastigotes, was inhibited by hydroxyurea. 3-methoxybenzamide and other antagonists of adp-ribosyltransferase (adprt) specifically inhibited differentiation at a very early stage in both experimental systems. cell proliferation (in the absenc ... | 1988 | 3135201 |
| effects of temperature elevation on mrna and protein synthesis in leishmania mexicana amazonensis. | the transition from the promastigote stage to the amastigote stage in leishmania appears to involve a sequence of steps which enable the parasite to adapt to its new environment. in this study, transformation from the promastigote to an amastigote-like stage was induced by temperature elevation and the effects on protein synthesis and the mrna population were analyzed. whereas significant changes in the polypeptide complement of the cell were observed, few, if any, changes were seen at the level ... | 1988 | 3173431 |
| effects of phorbol ester on leishmania mexicana amazonensis: an ultrastructural and cytochemical study. | promastigotes and amastigotes of leishmania mexicana amazonensis, incubated in the presence of 20 ng/ml of 12-o-tetradecanoyl phorbol-13-acetate (tpa), an exogenous protein kinase c activator, developed several membrane and cytoplasmic alterations. increased exocytic activity was observed especially in the amastigotes which had an enlarged flagellar pocket. treatment with tpa induced protrusions of the plasma membrane where cytoplasmic elements (ribosomes and sub-pellicular microtubules) were no ... | 1988 | 3179996 |
| temperature effects on molecular processes which lead to stage differentiation in leishmania. | we have studied the effects of growth phase and temperature on the morphological and molecular processes that occur during stage differentiation of leishmania. parasites which differ in their ability to transform axenically were compared. a typical heat shock response is observed in strains that transform axenically. heat shock proteins (hsps) of 70 and 83 kd are transcribed and synthesized along with a decrease in cellular protein synthesis, including tubulin. changes in the transcription of th ... | 1988 | 3181145 |
| membrane glycoprotein m-2 protects against leishmania amazonensis infection. | previous passive antibody transfer experiments have indicated that immunity to a 46-kilodalton membrane glycoprotein (m-2) of leishmania amazonensis may protect against infection with this parasite. in the studies described in this paper, we investigated the ability of the purified m-2 molecule to elicit a protective immune response in conjunction with freund incomplete and complete adjuvants, saponin, and corynebacterium parvum. both relatively susceptible (balb/c and cba) and resistant (c57bl/ ... | 1988 | 3182080 |
| beta tubulin gene of the parasitic protozoan leishmania mexicana. | a genomic dna library was generated with sau3a cut dna derived from promastigotes of leishmania mexicana amazonensis and the lambda vector embl3. the library was screened for beta tubulin clones using 32p-labeled heterologous probe of chicken beta tubulin cdna. from the various genomic clones the one designated 23.1, which gave the simplest hybridization banding pattern, was further characterized. the leishmanial insert dna was subcloned into plasmid vectors and the resulting clones were designa ... | 1988 | 3185616 |
| interactions between malaria (plasmodium yoelii) and leishmaniasis (leishmania mexicana amazonensis): effect of concomitant infection on host activity, host body temperature, and vector engorgement success. | | 1988 | 3204626 |
| interactions between plasmodium yoelii and leishmania mexicana amazonensis in leishmania resistant c57b1/6 mice. | we examined the effect of concurrent infection with plasmodium yoelii and leishmania mexicana amazonensis on the course of each disease in leishmania resistant c57bl/6 mice. p. yoelii parasitemia was greatly enhanced when l. m. amazonensis was inoculated 2 days, 3 weeks, or 12 weeks prior to the malaria. lesions due to l. m. amazonensis were enhanced in mice concomitantly infected with p. yoelii compared to mice infected with l. m. amazonensis only. metastatic l. m. amazonensis lesions developed ... | 1988 | 3207174 |
| novel 17-kilodalton leishmania antigen revealed by immunochemical studies of a purified glycoprotein fraction recognized by murine t lymphocytes. | recently, a glycoprotein fraction, designated gp10/20, purified from leishmania mexicana amazonensis was shown to induce a cellular immune response mediated by murine l3t4+ t lymphocytes. this fact led us to pursue further the characterization of this fraction. the present study demonstrated that gp10/20 is a degradation product of a 17-kilodalton antigen present in promastigotes and amastigotes of l. mexicana amazonensis. this antigen was easily detected in promastigotes of l. mexicana mexicana ... | 1988 | 3260220 |
| acid protease activity of a major surface membrane glycoprotein (gp63) from leishmania mexicana promastigotes. | a unique protease with activity optimal at ph 4.0 and trailing toward the alkaline ph spectrum was detected with intact glutaraldehyde-fixed promastigotes of leishmania mexicana amazonensis, indicating surface localisation of the enzyme. that this surface protease may be a virulence factor is suggested by its apparent roles in multiple steps during leishmanial infections of macrophages. indeed, its specific activity was 2-2.5 fold higher on virulent cells than on avirulent cells. several lines o ... | 1988 | 3278222 |
| macrophage function in patients with american cutaneous leishmaniasis: in vitro cytotoxicity and interleukin-1 production. | monocyte-derived blood macrophages of untreated patients with leishmania braziliensis or leishmania mexicana amazonensis infections show anomalies in their nonspecific immune functions. their ability to kill hela cells or to produce interleukin-1 in vitro in response to lipopolysaccharide plus candida albicans is lower than controls indicating that acquired or innate macrophage deficiencies may be involved in the course of the disease. | 1987 | 3305852 |
| from lysosomes to cells, from cells to leishmania: amino acid esters as potential chemotherapeutic agents. | amino acid esters can disrupt lysosomes and damage monocytes and certain lymphocyte populations. lysosomal disruption involves ph trapping of the esters, followed by their hydrolysis by as yet unidentified enzymes. accumulation of the more polar amino acids is assumed to cause osmotic lysis of the organelles. we have discovered that certain amino acid esters and amides destroy leishmania mexicana amazonensis amastigotes lodged within macrophages in culture, as well as parasites isolated from mou ... | 1987 | 3331952 |
| the transmission of suprapylarian leishmania by the bite of experimentally infected sand flies (diptera: psychodidae). | lutzomyia furcata transmitted leishmania chagasi to a hamster 10 days after being experimentally fed on an infected spleen. an individual female psychodopygus carrerai carrerai that had fed on a hamster lesion caused by leishmania mexicana amazonensis transmitted this parasite 6 days later to another hamster. transmission electron microscopy of this fly's head revealed a small number of degenerate promastigotes in the foregut, but only a few were attached. | 1987 | 3333811 |
| [cutaneous leishmaniasis caused by leishmania mexicana amazonensis in panama]. | | 1988 | 3347765 |
| vaccination of mice against leishmania mexicana amazonensis with microsomal fraction associated with bcg. | attempts to develop a satisfactory vaccine against new world cutaneous leishmaniasis have been made with varying success. we found that in mice, pretreated subcutaneously with 2 x 10(6) bcg organisms 2 weeks prior to immunization at the same site with as low as 10 micrograms of a microsomal preparation (pol-f) of leishmania mexicana amazonensis, a profound alteration was observed in the course of infection produced by inoculation of virulent amastigotes of the same strain. the bcg-pol-f vaccine ... | 1988 | 3370128 |
| freeze-fracture and cytochemistry study of the interaction between leishmania mexicana amazonensis and macrophages. | the process of interaction between macrophages and promastigote and amastigote forms of leishmania mexicana amazonensis was analyzed using freeze fracture and cytochemistry. the promastigotes inside endocytic vacuoles of macrophages presented an altered distribution of intramembranous particles and a wavy aspect of the plasma membrane. however, amastigotes did not show such alterations. the membrane alterations are probably caused by intracellular cell lysis of the promastigotes by the macrophag ... | 1988 | 3370624 |
| destruction of intracellular and isolated leishmania mexicana amazonensis amastigotes by amino acid amides. | l-amino acid esters such as leucine methyl ester (leu-ome) destroy leishmania mexicana amazonensis amastigotes by a mechanism which may involve hydrolysis of the compounds by parasite enzymes. moreover, several esters (e.g. ile-ome) prevent the killing of parasites by leu-ome, perhaps by inhibition of the hydrolytic enzymes. we show here that certain amino acid amides are also leishmanicidal. killing of leishmania within macrophages was assessed microscopically, and that of isolated amastigotes ... | 1988 | 3374965 |
| heme binding to leishmania mexicana amazonensis. | leishmania mexicana amazonensis is a pathogenic parasite whose growth, due to a biosynthetic deficiency, is dependent on a supply of exogenous heme. utilizing [55fe]hemin, we have demonstrated that heme binding to non-dividing cultured promastigotes of l. m. amazonensis at 4 degrees c reaches equilibrium within 6 h, is 95% dissociable by 28 h and is elevated approximately 5-fold by decreasing the ph of the binding buffer to 5.4. metalloporphyrins substituted either at the central metal atom or i ... | 1988 | 3386686 |
| generation of sequence diversity in the kinetoplast dna minicircles of leishmania mexicana amazonensis. | in order to understand the mechanisms which generate minicircle sequence diversity, we sequenced three minicircles belonging to the same or closely related sequence classes from the kinetoplast dna of leishmania mexicana amazonensis strains, ph8, raimundo, and josefa. closely related minicircles from ph8 and raimundo were unexpectedly found to differ at 11% of positions within the evolutionarily conserved region, but at only 3.9% of positions in the variable region. it thus appears that accumula ... | 1988 | 3398889 |
| feeding-site selection of lutzomyia longipalpis (diptera: psychodidae) on mice infected with leishmania mexicana amazonensis. | | 1988 | 3404541 |
| proteinase inhibitors protect leishmania amazonensis amastigotes from destruction by amino acid esters. | lysosomotropic amino acid esters and amides kill leishmania amazonensis amastigotes by a mechanism which probably involves enzymatic hydrolysis of the compounds and rapid accumulation of less permeant amino acid within the parasites. we show here that, in agreement with this model, the proteinase inhibitors antipain and chymostatin prevented the killing of intracellular and isolated parasites by l-leucine methyl ester (leu-ome). survival of leishmania within macrophages was assessed microscopica ... | 1988 | 3412375 |
| [cutaneous leishmaniasis caused by leishmania mexicana amazonensis in panama]. | | 1987 | 3423320 |
| interleukin-2 production during murine infection by leishmania mexicana amazonensis. | highly susceptible balb/c mice, resistant c57b1/6 and their f1 progeny (bdf1) were infected subcutaneously in the foot pad with leishmania mexicana amazonensis. at various times after infection, spleen or draining popliteal lymph node cells were assayed for their capacity to generate interleukin-2 (i1-2) by concanavalin a (cona) stimulation. in both balb/c and c57b1/6 strains there was a transient increase in their capacity to produce i1-2, from the 3rd to the 10th week post-infection. return to ... | 1986 | 3491949 |
| histopathologic changes induced by vaccination in experimental cutaneous leishmaniasis of balb/c mice. | highly susceptible balb/c mice became partially resistant to leishmania mexicana amazonensis infection after intravenous immunization with solubilized homologous promastigote antigen. immunized balb/c mice exhibited mixed mononuclear cell reactions, with granulomatous inflammation, collagen deposition, and fibrinoid necrosis at the site of infection. in contrast, naive animals displayed a monomorphic picture composed of largely vacuolated and parasitized macrophages with areas of coagulative nec ... | 1987 | 3495185 |
| infective stages of leishmania in the sandfly vector and some observations on the mechanism of transmission. | infective stages of leishmania (leishmania) amazonensis, capable of producing amastigote infections in hamster skin, were shown to be present in the experimentally infected sandfly vector lutzomyia flaviscutellata 15, 25, 40, 49, 70, 96 and 120 hours after the flies had received their infective blood-meal. similarly, infective stages of leishmania (l.) chagasi were demonstrated in the experimentally infected vector lu. longipalpis examined 38, 50, 63, 87, 110, 135, 171 and 221 hours following th ... | 1987 | 3507574 |
| expression and size heterogeneity of a 63 kilodalton membrane glycoprotein during growth and transformation of leishmania mexicana amazonensis. | our previous work by immunoprecipitation with a specific monoclonal antibody showed multiple, closely apposed electrophoretic bands of a major surface antigen specific to the promastigote stage of leishmania mexicana amazonensis. here, we analyzed the antigen during growth and transformation of this parasite with particular emphasis on the origin of the multiple bands. immunobinding assays revealed the presence of the antigen throughout all phases of growth of cloned and uncloned promastigotes i ... | 1986 | 3515177 |
| structural and antigenic characterization of a species- and promastigote-specific leishmania mexicana amazonensis membrane protein. | a leishmania mexicana amazonensis promastigote membrane glycoprotein (mr 46,000) expressing the species-specific and promastigote-specific epitope of monoclonal antibody ix 2h7-e10(m-2) has been purified to homogeneity, and studies have been made to determine the minimum peptide fragment that retained antigenic activity. peptide mapping experiments performed with the metabolically labeled or surface radioiodinated protein illustrated its highly folded nature and marked resistance to proteolytic ... | 1987 | 3543130 |
| identification of specific and cross-reactive antigens of leishmania donovani chagasi by human infection sera. | cloned leishmania donovani chagasi (ldc) promastigotes were analyzed by sds-page separation and immunoblotting with human infection sera. the patterns of antigen reactivity were compared by using sera from individuals with ldc, leishmania mexicana amazonensis (lma), trypanosoma cruzi, mycobacterium tuberculosis, or mycobacterium leprae infections. sera from individuals with these infections recognized ldc antigens in several m.w. ranges. reactivity was due to recognition of ldc molecules and not ... | 1987 | 3543131 |
| cutaneous leishmaniasis. the defect in t cell influx in balb/c mice. | local cellular responses to cutaneous infection with leishmania mexicana amazonensis were examined in susceptible (balb/c) and resistant (c57bl/6) mouse strains by immunocytochemical and electron microscopic studies. infection during the first 8 wk in both animal strains was characterized by progressively enlarging lesions, epidermal thickening and ulceration, and accumulation of eosinophils and ia+ infected macrophages. healing of c57bl/6 mouse lesions began after 12 wk of infection and was ass ... | 1987 | 3546576 |
| leishmania mexicana: distribution of intramembranous particles and filipin sterol complexes in amastigotes and promastigotes. | the density and distribution of intramembranous particles was analyzed in freeze fracture replicas of the plasma membrane of amastigotes, and infective as well as noninfective promastigotes of leishmania mexicana amazonensis. the density of intramembranous particles on both protoplasmic and extracellular faces was higher in infective than in noninfective promastigotes and it was lower in amastigotes than in promastigotes. amastigotes purified immediately after tissue homogenization were surround ... | 1987 | 3569471 |
| [epidemiological characteristics of american cutaneous leishmaniasis in an endemic region of the state of bahia. iii. phlebotomine fauna]. | the phlebotomine fauna is highly varied in três braços, an endemic area of american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of bahia state, brazil. thirty spécies of the lutzomyia genus were identified in 13,535 specimens collected between 1976 and 1984. lutzomyia whitmani was the dominant species accounting for 99% of flies in the peridomicile and 97.5% of those caught in homes. in the forest the predominant species were lu. ayrozai and lu. yuilli. lu. whi ... | 1986 | 3574127 |
| structural observations on the attachment of promastigotes of leishmania mexicana amazonensis to the surface of macrophages. | | 1986 | 3587059 |
| destruction of leishmania mexicana amazonensis promastigotes by normal human serum. | fresh normal human serum was observed to have a lethal effect on leishmania mexicana amazonensis promastigotes obtained from laboratory-bred lutzomyia longipalpis or on promastigotes grown in liquid culture medium, inoculated with the same isolates. heat inactivation abolished the leishmania lytic activity from the sera. resistance of culture promastigotes to lysis by normal human serum was investigated in three isolates of l. m. amazonensis. development of resistance (up to 7%) was found in onl ... | 1987 | 3605505 |
| observations on the parasite leishmania mexicana amazonensis and its natural infection of the sand fly lutzomyia olmeca nociva. | | 1987 | 3607352 |
| fine structure and cytochemistry of the interaction between leishmania mexicana amazonensis and rat neutrophils and eosinophils. | the fine structure of the in vivo and in vitro interaction process between promastigote and amastigote forms of leishmania mexicana amazonensis with rat peritoneal neutrophils and eosinophils was studied. for in vivo experiments the parasites were inoculated into the peritoneal cavity and samples were collected after different times. both neutrophils and eosinophils readily ingested and digested the parasites within endocytic vacuoles. attachment of the parasites to the eosinophils induced their ... | 1987 | 3612880 |
| identification of a major 72 kilodalton surface antigen in twelve isolates of leishmania braziliensis braziliensis. | the study of the surface antigens of leishmania braziliensis braziliensis revealed a great homogeneity among ten strains isolated from bolivia and two reference strains from brazil and belize. a 72 kda major protein, present in all l. b. braziliensis strains, was recognized by both cutaneous and mucocutaneous human sera, but was not recognized by kala-azar and chagasic sera. no cross-reactive antigens were found among strains of leishmania braziliensis guyanensis, leishmania braziliensis panamen ... | 1987 | 3627165 |
| destruction of leishmania mexicana amazonensis amastigotes by leucine methyl ester: protection by other amino acid esters. | l-amino acid esters, such as leucine methyl ester (leu-ome) can destroy intracellular as well as isolated amastigotes of leishmania mexicana amazonensis by a mechanism which may involve ester hydrolysis by parasite enzymes. we show here that several other esters prevented the killing of the amastigotes by leu-ome. destruction of leishmania within macrophages in culture was assessed microscopically and viability of isolated parasites was monitored by reduction of the tetrazolium mtt. the main fea ... | 1987 | 3670898 |
| leishmaniasis in brazil. xxiv. natural flagellate infections of sandflies (diptera: psychodidae) in pará state, with particular reference to the rôle of psychodopygus wellcomei as the vector of leishmania braziliensis braziliensis in the serra dos carajás. | between july 1983 and december 1984 natural flagellate infections were found in 114 (1%) of 11,586 female phlebotomine sandflies (diptera: psychodidae) of 21 species. a further 1084 females of 17 other species were not infected. identification of the organisms on a number of occasions confirms the exclusive parasite/vector relationship of leishmania mexicana amazonensis/lutzomyia flaviscutellata and le. braziliensis braziliensis/psychodopygus "wellcomei". undescribed or unidentified leishmania s ... | 1987 | 3686628 |
| detection and enumeration of leishmania in sand flies using agar-based media. | an agar plating technique was used to determine the number of amastigotes ingested by lutzomyia longipalpis fed on papules on mesocricetus auratus caused by leishmania mexicana amazonensis and on lesions on mystromys albicaudatus caused by leishmania braziliensis panamensis. the technique involved homogenizing sand flies after bloodfeeding on the infected animals and spreading the homogenate over the surface of agar plates. a great variation in the number of amastigotes ingested by individual sa ... | 1987 | 3688307 |
| effect of temperature on leishmania mexicana amazonensis induced lesions in hamsters. | | 1987 | 3692556 |
| cell surface carbohydrate of leishmania mexicana amazonensis: differences between infective and non-infective forms. | the cell surface carbohydrates of leishmania mexicana amazonensis (amastigotes and promastigotes, both infective and non-infective forms) were comparatively analyzed by agglutination assay employing 28 highly purified lectins, and by binding assay using 125i-labeled lectins. among the d-galnac binding lectins, bandeiraea simplicifolia-i, dolichos biflorus, phaseolus vulgaris and glycine max were highly specific for the amastigotes, while that from maclura aurantiaca selectively agglutinated prom ... | 1986 | 3709546 |
| the experimental transmission of leishmania mexicana amazonensis lainson & shaw, between hamsters by the bite of lutzomyia furcata (mangabeira) | | 1986 | 3726982 |
| isolation of leishmania mexicana amazonensis from the bone marrow in a case of american visceral leishmaniasis. | the first documented human case of visceral leishmaniasis caused by l. mexicana amazonensis is reported. leishmania were isolated from bone marrow aspirate material from a typical visceral leishmaniasis patient. further characterization by isoenzyme electrophoresis and by a panel of species- and subspecies-specific monoclonal antibodies established its classification as l. m. amazonensis. | 1986 | 3728794 |
| leishmania mexicana amazonensis infections in 'resistant' inbred mice following removal of the draining lymph node. | highly resistant (c57bl/10) and intermediately resistant (dba/2) mice were infected subcutaneously with leishmania mexicana amazonensis in a hind footpad subsequent to removal of the draining popliteal node. these mice developed greatly exacerbated leishmania infections as compared to sham-operated controls or to mice infected in the contralateral footpad. the majority of mice in which the draining lymph nodes were removed prior to infection developed metastases, lost their delayed hypersensitiv ... | 1986 | 3731529 |
| experimental infection of lutzomyia longipalpis fed on a patient with cutaneous leishmaniasis due to leishmania mexicana amazonensis. | | 1986 | 3796279 |
| [note on the relations between vectors of leishmaniasis and forest trees in french guiana]. | the study of relationships between phlebotomine sandflies and different species of trees, 0 to 1.5 m above ground, was carried out in the french guiana forest. we found that certain forest trees are more propitious than others to the development or maintenance of certain leishmaniasis vectors. lu. umbratilis, vector of leishmania braziliensis guyanensis, represents between 28 and 88% of samples collected on trunks. the association of lu. umbratilis and lu. rorotaensis represents between 58 and 9 ... | 1986 | 3813430 |
| leishmania mexicana: destruction of isolated amastigotes by amino acid esters. | amino acid esters can destroy intracellular as well as isolated amastigotes of leishmania mexicana amazonensis. in the present study we examined, using a tetrazolium reduction assay, the toxicity of the esters for amastigotes isolated from mouse lesions. parasite killing by the "prototype" compound l-leucine methyl ester at 1 mm concentration and at ph 7.3 took place within 15-30 min. time-lapse cinematographic observations showed that the amastigotes rounded up and became less phase-dense befor ... | 1987 | 3826487 |
| the activity of plumbagin and other electron carriers against leishmania donovani and leishmania mexicana amazonensis. | | 1985 | 3834847 |
| flagellates in the malpighian tubules of laboratory-bred lutzomyia longipalpis fed on a hamster experimentally infected with leishmania mexicana amazonensis. | as a preparatory stage for a study aiming at identifying the species and subspecies of local leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method. | 1985 | 3837172 |
| receptor-mediated entry of peroxidases into the parasitophorous vacuoles of macrophages infected with leishmania mexicana amazonensis. | leishmania amastigotes, obligatory parasites of macrophages, lodge and multiply within long-lived phagolysosomelike "parasitophorous vacuoles" (pv). the glycoprotein horseradish peroxidase (hrp) was shown, by light and electron microscopic cytochemistry, to enter the pvs of rat in vitro-derived bone marrow macrophages infected with leishmania mexicana amazonensis. uptake was obtained both in preinfected macrophages incubated with hrp and in macrophages pulsed with hrp, infected, and further incu ... | 1985 | 3855437 |
| hypergammaglobulinaemia in leishmania donovani infected hamsters: possible association with a polyclonal activator of b cells and with suppression of t cell function. | studies were carried out on the mechanisms by which b lymphocytes are polyclonally activated to secrete antibodies during visceral leishmaniasis. crude extracts of leishmania donovani, the aetiological agent of this disease, of leishmania mexicana amazonensis, the etiological agent of cutaneous leishmaniasis, and of herpetomonas muscarum, a related non-pathogenic organism, all contain components which cause strong in vitro polyclonal activation of hamster spleen cells leading to the production o ... | 1985 | 3872189 |
| [efficacy of the vaccination of c57bl/6 mice against infection with different species of leishmania]. | antigens were isolated from lysates of promastigotes of leishmania infantum by electro-elution from polyacrylamide gels. antigens with respective molecular weights for f2 = 94-67 kd; f5 = 30-20 kd and f6 below 20 kd, were injected intravenously in c 57 bl/6 mice. the immune sera were studied by indirect immunofluorescence; an in vivo test showed their inhibitory effect on the life cycle of several leishmania species from the old and the new world. furthermore, mice immunized with f2, f5 or f6 we ... | 1985 | 3936605 |
| destruction of leishmania mexicana amazonensis amastigotes within macrophages by lysosomotropic amino acid esters. | leishmania amastigotes parasitize almost exclusively the mononuclear phagocytes of mammals. the organisms survive and multiply within acidified vacuoles (parasitophorous vacuoles; p.v.) akin to phagolysosomes. certain amino acid esters are known to accumulate in and disrupt lysosomes. we postulated that, since leishmania possess lysosome-like organelles, they may be susceptible to the potentially high ester concentrations attained in the p.v. we report here that l-amino acid esters can rapidly d ... | 1986 | 3950542 |
| cytochemical localization of acid phosphatase in leishmania mexicana amazonensis. | acid phosphatase was cytochemically detected at the ultrastructural level in infective and non-infective promastigotes and in amastigotes of the parasitic protozoan leishmania mexicana amazonensis. cerium chloride was used as the capture agent of the phosphate liberated during the hydrolysis of the substrate (na-beta-glycerophosphate). reaction product, indicative of enzyme activity, was seen in the outer face of the plasma membrane of many, but not all, infective and noninfective promastigote f ... | 1986 | 3959150 |
| [the 2 first cases of cutaneous leishmaniasis due to leishmania mexicana amazonensis in french guiana]. | the authors report the two first proven cases of cutaneous leishmaniasis due to leishmania mexicana amazonensis in french guiana. they present some observations on the situation of cutaneous leishmaniasis epidemiology in this country. | 1985 | 3986952 |
| depletion of secondary lysosomes in mouse macrophages infected with leishmania mexicana amazonensis: a cytochemical study. | leishmania amastigotes lodge and multiply within parasitophorous vacuoles, which can fuse with secondary lysosomes of the host macrophages. this study examines the effect of infection with amastigotes of l. mexicana amazonensis on the secondary lysosomes of mouse macrophage cultures. the cultures were stained for the activities of two lysosomal enzyme markers, acid phosphatase and arylsulfatase, and the light microscopic observations were supplemented by electron microscopy. nearly all noninfect ... | 1985 | 3993184 |
| [immunization of balb/c mice with cultured amastigotes of leishmania mexicana amazonensis: protection by gamma-irradiated parasites]. | | 1985 | 4012583 |
| fine structure and cytochemistry of the endoplasmic reticulum and its association with the plasma membrane of leishmania mexicana amazonensis. | promastigotes of leishmania mexicana amazonensis possess an elaborated system of cytoplasmic membranes which is clearly visualized when the cells are fixed in a glutaraldehyde solution containing ca++ and post-fixed in an osmium tetroxide solution containing ca++ and potassium ferricyanide. when the parasites are incubated in a medium containing glucose-6-phosphate and lead nitrate, reaction product indicative of glucose-6-phosphatase activity is seen in the membrane system confirming that it co ... | 1985 | 4020925 |
| natural hosts of leishmania mexicana amazonensis lainson and shaw, 1972 (kinetoplastida: trypanosomatidae) in french guiana. | | 1985 | 4035728 |
| development of infective stage leishmania promastigotes within phlebotomine sand flies. | midgut promastigotes were obtained from phlebotomus papatasi and lutzomyia longipalpis on days 3-7 after infection with cloned isolates of leishmania major and leishmania mexicana amazonensis, respectively, and examined as to their ability to initiate cutaneous infections in balb/c mice. sequential development of midgut promastigotes from a noninfective to an infective stage was confirmed for both the new world and old world species. the generation of infective promastigotes from rapidly dividin ... | 1985 | 4039899 |
| heme requirement and acquisition by extracellular and intracellular stages of leishmania mexicana amazonensis. | the inability to synthesize heme, a well known metabolic defect of trypanosomatid protozoa, accounts for their growth requirement for heme compounds in vitro. we now extend this finding to a pathogen leishmania mexicana amazonensis, especially the intracellular replicative stage of amastigotes in the macrophage. we measured the level of heme and its biosynthetic enzymes, aminolevulinate dehydratase and porphobilinogen deaminase in the parasites and in infected and non-infected macrophages of j77 ... | 1985 | 4058483 |
| [current aspects of endemic mucocutaneous leishmaniasis in brazil]. | mucocutaneous leishmaniasis has a large incidence in brazil. biochemical, immunological and biological studies have characterized three disease agents: leishmania mexicana amazonensis, leishmania brasiliensis guyanensis and leishmania brasiliensis brasiliensis; these have distinct geographical distributions. the last one is the most common and is the most difficult to treat. destructive mucosal lesions can occur days, months or years after the cutaneous lesions. the montenegro intradermal test, ... | 1985 | 4066323 |
| [effect of sex hormones on experimental infections induced by a strain of leishmania mexicana amazonensis from venezuela]. | | 1985 | 4095406 |
| leishmaniasis in brazil. vi. observations on the seasonal variations of lutzomyia flaviscutellata in different types of forest and its relationship to enzootic rodent leishmaniasis (leishmania mexicana amazonensis). | | 1972 | 4647642 |
| letter: further evidence of the rôle of lutzomyia flaviscutellata (mangabeira) as the vector of leishmania mexicana amazonensis in brazil. | | 1973 | 4785465 |
| accumulation of [125sb]sodium stibogluconate by leishmania mexicana amazonensis and leishmania donovani in vitro. | | 1981 | 6108831 |
| potentiating action of rifampicin and isoniazid against leishmania mexicana amazonensis. | the treatment of the complex of diseases known as leishmaniasis, caused by infection with protozoal parasites, is often unsatisfactory. the response to chemotherapy depends not only on the species of infecting leishmania but also on the immune reactions of the host. this creates difficulties in evaluating any new drug in clinical trials. in a brazilian patient with diffuse cutaneous leishmaniasis, which classical antileishmanial drugs had failed to cure, antituberculous therapy of an intercurren ... | 1981 | 6112485 |
| leishmania mexicana: temperature sensitivity of isolated amastigotes and of amastigotes infecting macrophages in culture. | different temperature requirements for intracellular growth of leishmania spp. may account for the predominantly peripheral or visceral localization of the parasites in the vertebrate host. we show here that leishmania mexicana amazonensis, an agent of cutaneous disease, is growth restricted in vitro at 37.5 c and viable at 34 c. this temperature sensitivity has been observed in both infected macrophage cultures and isolated amastigotes. counts of the percentage of infected macrophages and of th ... | 1983 | 6196227 |
| receptor-mediated entry of beta-glucuronidase into the parasitophorous vacuoles of macrophages infected with leishmania mexicana amazonensis. | 125i-labeled rat preputial gland beta-glucuronidase was shown by light and electron microscopic radioautography to accumulate within the parasitophorous vacuoles of in vitro derived bone marrow macrophages infected with leishmania mexicana amazonensis. beta-glucuronidase uptake was mediated by the mannose receptor, since the penetration of the ligand was inhibited by mannan. uptake was detected as soon as 4 h after incubation of infected cells with the ligand, and increased at 24 and 48 h. the l ... | 1983 | 6304225 |
| the enzymes of purine salvage in trypanosoma cruzi, trypanosoma brucei and leishmania mexicana. | we have previously shown the presence of various purine salvage enzymes in trypanosoma cruzi, including phosphoribosyltransferase, aminohydrolase, kinase, phosphorylase and hydrolase activities. we now report that a similar situation occurs in leishmania mexicana amazonensis and trypanosoma brucei brucei. in all three organisms we found higher levels of activity for the phosphoribosyltransferase enzymes than for the nucleoside kinases, suggesting a preference for the salvage of purine bases rath ... | 1983 | 6316234 |
| inhibition by superoxide dismutase and catalase of the damage of isolated leishmania mexicana amazonensis by phenazine methosulfate. | phenazine methosulfate, a cationic electron carrier, inhibits the extracellular growth of promastigotes and the conversion of amastigotes into promastigote forms of leishmania mexicana amazonensis. growth inhibition and damage of extracellular parasites by pms was counteracted by superoxide dismutase, a scavenger of the superoxide anion (o2-), and to a lesser extent, by catalase, a scavenger of hydrogen peroxide (h2o2). inactivated dismutase and catalase were ineffective. thus, damage of isolate ... | 1984 | 6328296 |
| detection of promastigote stage-specific antigens on leishmania mexicana amazonensis developing in the midgut of lutzomyia longipalpis. | previously described monoclonal antibodies ix-if9-d8, ix-2h7-e10 and ix-5h9-c1 recognize promastigote stage-specific determinants present on externally exposed membrane proteins of axenically cultured leishmania mexicana amazonensis. in the present study, these antigens were demonstrated by indirect immunofluorescence to be present on promastigotes found in the gut lumen of infected lutzoymia longipalpis. the presence of these antigens on promastigotes found in infected sandflies suggests that t ... | 1983 | 6359907 |
| formation of (1----2)-linked beta-d-mannopyranan by leishmania mexicana amazonensis: relationship with certain crithidia and herpetomonas species. | | 1984 | 6491853 |
| amyloidosis in experimental tegumentary leishmaniasis in mice. | renal and hepatosplenic amyloidosis was found in chronic cutaneous leishmaniasis in mice infected with 10(6) purified amastigotes from lesions produced by the h21 strain of leishmania mexicana amazonensis. after 1 year a progressive lesion leading to metastasis was observed in most animals. | 1984 | 6507735 |
| [cutaneous leishmaniasis in amazonia. report of the 1st human case of mixed infection, determined by 2 different leishmania species: leishmania brasiliensis and leishmania mexicana amazonensis]. | | 1984 | 6533750 |
| differential expression of mrnas for alpha- and beta-tubulin during differentiation of the parasitic protozoan leishmania mexicana. | the parasitic protozoan leishmania mexicana amazonensis has two developmental stages: a motile flagellated promastigote stage and a sessile intracellular amastigote stage. in our previous work, cells of the promastigote stage were found to synthesize more tubulin protein than those of the amastigote stage. here, tubulin mrnas in these leishmanias were analyzed. based on dot blot hybridization between total leishmanial rna and tubulin-specific cdna probes derived from chicken brain, amastigotes a ... | 1984 | 6592587 |
| leishmania mexicana amazonensis: surface charge of amastigote and promastigote forms. | the surface charge of leishmania mexicana amazonensis was evaluated by means of the binding of colloidal iron hydroxyde particles at ph 1.8 and cationized ferritin particles at ph 7.2 to the cell surface, visualizated by electron microscopy and by direct measurements of the electrophoretic mobility of cells suspended in solutions of different ph. the following forms of the parasite were analysed: amastigotes (surrounded or not by the membrane of the endocytic vacuole, isolated from lesions), tra ... | 1983 | 6617803 |
| isolation and purification of amastigotes of leishmania mexicana amazonensis by a gradient of metrizamide. | | 1983 | 6631632 |
| leishmaniasis in brazil: xx. prevalence of "enzootic rodent leishmaniasis" (leishmania mexicana amazonensis), and apparent absence of "pian bois" (le. braziliensis guyanensis), in plantations of introduced tree species and in other non-climax forests in eastern amazônia. | in amazonian brazil most human leishmaniasis is due to leishmania braziliensis s.l. and is acquired during the clearing of primary climax forest. one of the largest deforestation projects has taken place on the jari property where plantations of exotic tree species are grown for paper pulp. the ability of the regional leishmaniasis enzootics to invade plantations was investigated. cdc light-trap catches indicated the phletobomine vectors of le. b. guyanensis (causing "pian bois" in man) to be ve ... | 1983 | 6665830 |
| immunopathology of experimental cutaneous leishmaniasis. | relatively susceptible balb/c and relatively resistant a/j mice were infected subcutaneously in the right hind footpad with promastigotes of leishmania mexicana amazonensis. a large localized lesion developed within 2 months after infection in the balb/c mice, while a/j mice exhibited a small discrete fibrotic nodule. sequential immunologic and histologic examination demonstrated that balb/c mice developed a nodular foam-cell type of lesion and progressive depression of a delayed-type hypersensi ... | 1984 | 6691411 |
| ump synthesis in the kinetoplastida. | all six enzymes of pyrimidine biosynthesis de novo have been detected in homogenates of the culture promastigote form of leishmania mexicana amazonensis, the blood trypomastigote form of trypanosoma brucei and the culture epimastigote, blood trypomastigote and intracellular amastigote forms of trypanosoma cruzi. dihydroorotate dehydrogenase is mitochondrial in mammals, but the isofunctional enzyme, dihydroorotate oxidase was found to be cytoplasmic, whereas orotate phosphoribosyltransferase and ... | 1982 | 6753942 |
| leishmaniasis in brazil. xiv. leishmanial and trypanosomal iga antibody in patients with leishmaniasis and chagas's disease. | preserved sera from patients with various forms of leishmaniasis, acute and chronic chagas's disease and from normal individuals were examined for the presence of igg and iga antibodies by the ifa test. the leishmanial antigen used in the ifa test was prepared from a hamster infected with the ph8 strain of leishmania mexicana amazonensis; amastigotes were isolated from a skin lesion and fixed in formal phosphate-buffered saline-glucose for slide antigen. there were significantly more positive re ... | 1981 | 6795770 |
| leishmania mexicana: acid phosphatase ultrastructural cytochemistry of infected mouse macrophage cultures treated with phenazine methosulfate. | bone marrow-derived mouse macrophage cultures infected with leishmania mexicana amazonensis amastigotes were given a 2-hr pulse with 10 microm phenazine methosulfate (pms), a cationic electron carrier which destroys the intracellular parasites. cultures were fixed at different times after the pms pulse and processed for the detection of acid phosphatase (acp) activity at the electron microscopic level. only a small proportion of nontreated, infected macrophages stained for acp. in contrast, 2 to ... | 1983 | 6832281 |
| uptake and killing of leishmania mexicana amazonensis amastigotes by human skin fibroblasts. | this paper describes the in vitro infection of human established fibroblast lines by leishmania mexicana amazonensis amastigotes. intracellular parasites were located within vacuoles. the proportion of infected cells reached a peak of about 50% on days 2 or 3, and decreased to almost 0 on days 6 or 8. transmission electron microscopy was used to document different stages of the degeneration of l. m. amazonensis amastigotes on days 4 and 5. the proportion of infected fibroblasts decreased in both ... | 1983 | 6882054 |
| tubulin biosynthesis in the developmental cycle of a parasitic protozoan, leishmania mexicana: changes during differentiation of motile and nonmotile stages. | cytodifferentiation in the transition cycle of the parasitic protozoan leishmania mexicana amazonensis was studied in vitro. the flagellated motile promastigotes transform into the nonmotile amastigotes in 7 days at 35 degrees c intracellularly in the murine macrophage line j774g8. in medium 199 plus fetal bovine serum, the reverse transformation occurs extracellularly at 27 degrees c in 2 days. slab gel electrophoresis of leishmanias labeled with [35s]methionine during transformation revealed c ... | 1981 | 6950404 |
| surface antigenic change during differentiation of a parasitic protozoan, leishmania mexicana: identification by monoclonal antibodies. | the fusion of sp2/0 myeloma cells with spleen cells from mice immunized with leishmania mexicana amazonensis promastigotes produced hybridoma clones. indirect immunofluorescent antibody assay with live leishmanias showed that the monoclonal antibody 6h12 recognized only the antigens bound to the surface of l. mexicana amazonensis promastigotes. it also showed that the antibody bound to neither amastigotes of this species nor to other leishmania species--i.e., l. braziliensis braziliensis, l. tro ... | 1982 | 6961414 |
| destruction of leishmania mexicana amazonensis amastigotes within macrophages in culture by phenazine methosulfate and other electron carriers. | exposure of macrophages infected with leishmania mexicana amazonensis to phenazine methosulfate (pms) resulted in rapid damage and disappearance of the intracellular amastigotes without obvious ill effects to the host cells. the reduction of the percent infection was related to the concentration of pms and to the duration of the pulse. most leishmania disappeared within 2 h of a 2-h pulse with 10 mum of the drug. in contrast, pretreatment of the macrophages with pms followed by removal of the dr ... | 1982 | 7057140 |
| effect of pentamidine isethionate on the ultrastructure and morphology of leishmania mexicana amazonensis in vitro. | | 1982 | 7082077 |
| monoclonal antibodies recognizing determinants specific for the promastigote state of leishmania mexicana. | two monoclonal antibodies (ix-if9-d8 and ix-5h9=c1) produced to a membrane enriched fraction of leishmania mexicana amazonensis promastigotes have been demonstrated to be specific for the promastigote (insect) form and not the amastigote (mammalian host) form of the parasite. the antigens recognized by these monoclonal antibodies are not found on amastigotes isolated from infected animals or on amastigotes isolated from a macrophage cell line j774 infected initially with promastigotes. the antig ... | 1982 | 7177168 |
| freeze-fracture study of the plasma membrane of leishmania mexican amazonensis. | the fine structure of the plasma membrane of promastigotes of leishmania mexicana amazonensis was studied by freeze-fracture techniques. measurement of the number of intramembranous particles per square micrometer of membrane area revealed a particle density of 2,040 +/- 213/micron2 on the p-face and 890 +/- 186/micron2 on the e-face. the particle density of the flagellar membrane was 448 +/- 53/micron2. clusters of intramembranous particles were seen on the flagellar membrane at the region of a ... | 1980 | 7218117 |
| isolation of an enriched plasma membrane-subpellicular microtubule fraction of leishmania mexicana amazonensis. | | 1980 | 7231156 |