| 'entamoeba histolytica' is a complex of two species. | | 1992 | 1412672 |
| [parasitic diseases in patients with impaired immune response. clinical picture and diagnosis]. | patients with impaired immune system are frequently infected with various parasitic diseases. the clinical picture is characterized by unusual manifestations and frequently severe recurrences of infections which are not normally serious. some almost parasitic microorganisms produce symptoms exclusively in patients with impaired immune system. parasitic infections have become increasingly common with the increasing number of patients who live for prolonged periods with impaired immune systems, of ... | 1992 | 1413170 |
| [the improvement of polyxenic cultivation of entamoeba histolytica type hk 9]. | the serological diagnosis of extraintestinal infections with e. histolytica by indirect immunofluorescence (ifat) requires a corpuscular antigen. this is produced in our laboratory via polyxenic cultivation of e. histolytica strain hk 9 in a nutrient medium containing a simple salt mixture (resembling the ringer-mixture), calf serum and rice starch. it was the aim of the experiments described in this paper to search for a useful medium in which the amebae grow in high density but without substan ... | 1992 | 1416222 |
| western blot of entamoeba histolytica antigenic fractions: reactivity analysis with sera from intestinal amoebiasis patients. | the reactivity of sera from acute-phase intestinal amoebiasis patients (two weeks evolution) was studied to determine which of the entamoeba histolytica antigens are most frequently immunogenic. sera were examined by means of immunoelectrotransferase assay using crude extract of hm1:imss e. histolytica trophozoites. three populations of clinically healthy adults from mexico, canada and germany, with no evidence of parasites in faeces, were used as controls. the frequency of antigen recognition w ... | 1992 | 1417202 |
| amebiasis. | entamoeba histolytica, the causative agent of amebiasis, was first described in 1875. although a large number of people throughout the world are infected with this organism, only a small percentage will develop clinical symptoms. morbidity and mortality due to e. histolytica vary from area to area and person to person. recent findings have suggested that there are pathogenic and nonpathogenic strains of e. histolytica that can be differentiated by isoenzyme (zymodeme) analysis, monoclonal antibo ... | 1992 | 1423215 |
| human chang liver cells show large surface openings and endocytic channels that resemble those in the amoeba. | cytolysis of host cells by pathogenic entamoeba histolytica can be blocked by specific lysozyme inhibitions and is recently reported to be enhanced by phosphoinositide (pi) signal transduction activation. however the mechanistic relationship between pi second messenger targets and massive lysosomal secretion needed to achieve rapid host cell lysis is unclear. we have previously shown that intracellular alkalinization associated with activated pi hydrolysis produces a massive endocytosis of huge ... | 1992 | 1428518 |
| humoral immune response against a 70-kilodalton heat shock protein of entamoeba histolytica in a group of patients with invasive amoebiasis. | in order to investigate the humoral immune response against entamoeba histolytica a lambda zapii cdna library was constructed from trophozoites of the pathogenic e. histolytica strain sfl-3. the library was screened with serum igg from a patient with invasive amoebiasis. forty-nine immunopositive lambda clones were isolated and partial sequences from the inserts were obtained. by comparison of the sequences with the merged database mipsx from the martinsried institute for protein sequences we we ... | 1992 | 1435858 |
| molecular cloning of cdna and genomic sequences coding for the 35-kilodalton subunit of the galactose-inhibitable lectin of pathogenic entamoeba histolytica. | | 1992 | 1435873 |
| in vivo activation of macrophages by ifn-gamma to kill entamoeba histolytica trophozoites in vitro. | to determine the role of interferon-gamma (ifn-gamma) in the activation of macrophages to kill entamoeba histolytica trophozoites in vitro, c57bl/6 mice were injected with various doses of recombinant ifn-gamma (rifn-gamma) by either the intravenous, intraperitoneal or intramuscular routes. mice were treated with doses of rifn-gamma ranging from 10(1) to 10(5) units. twenty hours later, peritoneal macrophages were harvested from the treated animals. macrophage monolayers were prepared and their ... | 1992 | 1437232 |
| cloning and expression of an nadp(+)-dependent alcohol dehydrogenase gene of entamoeba histolytica. | ethanol is the major metabolic product of glucose fermentation by the protozoan parasite entamoeba histolytica under the anaerobic conditions found in the lumen of the colon. here an internal peptide sequence determined from a major 39-kda amoeba protein isolated by isoelectric focusing followed by sds/page was used to clone the gene for the e. histolytica nadp(+)-dependent alcohol dehydrogenase (ehadh1; ec 1.1.1.2). the ehadh1 clone had an open reading frame that was 360 amino acids long and en ... | 1992 | 1438208 |
| enzyme-linked immunosorbent assay based on monoclonal and polyclonal antibodies for the detection of entamoeba histolytica antigens in faecal specimens. | a murine monoclonal antibody (mab) (eh208c2-2) raised against crude lysate of the pathogenic hm-1:imss strain of entamoeba histolytica was used in an enzyme-linked immunosorbent assay for the detection of e. histolytica antigens in faecal specimens. the detection limit of the assay was 110 and 280 amoebae/ml of the hm-1:imss and hk-9 strains in phosphate-buffered saline, respectively. the assay was applied to single stool samples from 3 groups of individuals comprising 40 patients whose stools w ... | 1992 | 1440778 |
| entamoeba histolytica: erythrophagocytosis, collagenolysis, and liver abscess production as virulence markers. | high rates of erythrophagocytosis and collagenolysis in vitro have been regarded as indicative of virulence in vivo of entamoeba histolytica trophozoites. in the present study, the erythrophagocytic index and the collagenolytic activity of 3 axenic lines of e. histolytica, strain hm1:imss, were measured. the 3 lines shared the same pathogenic zymodeme but showed clear-cut differences in the extent of liver damage induced in hamsters. a direct correlation between collagenolysis in vitro and the s ... | 1992 | 1440779 |
| axenic cultivation of entamoeba histolytica in suspension. | | 1992 | 1440780 |
| high cell surface hydrophobicity of virulent entamoeba histolytica isolates. | thirty isolates of entamoeba histolytica were examined for their cell surface hydrophobicity. it was observed that increased hydrophobicity of the trophozoites was associated with lesion-forming ability in hamster liver, a higher rate of erythrophagocytosis and greater resistance to complement. the relationship of cell surface hydrophobicity to other virulence markers in e. histolytica is discussed. | 1992 | 1440815 |
| cryptosporidiosis among patients with acquired immunodeficiency syndrome in zulia state, venezuela. | we studied the prevalence of cryptosporidium in 29 patients with acquired immunodeficiency syndrome (aids) from zulia state, venezuela. they ranged in age from five months to 46 years. two were children and 27 were adults, of which six were women. of the 21 men, 66.6% reported homosexual behavior. three stool samples from each patient were examined, and modified ziehl-neelsen carbolfuchsin staining of formalinether stool concentrates was used to identify cryptosporidium oocysts. to detect the pr ... | 1992 | 1449198 |
| oxido-reductive functions of entamoeba histolytica in relation to virulence. | entamoeba histolytica can reduce nitro-blue tetrazolium (nbt) in hank's balanced salt solution to almost the same extent as in eagle's minimal medium. further, this reduction was stimulated only to a minor degree by glucose, pyruvate and dl-serine, substrates known to support respiratory activity (o2 uptake) in e. histolytica. however, both nadh and nadph increased nbt reduction several-fold, the effect being greater with nadph. a sizeable proportion of this endogenous dye-reducing capability (i ... | 1992 | 1449272 |
| [recent findings on the pathogenicity of entamoeba histolytica]. | entamoeba histolytica is the causative agent of human amoebiasis. during recent years, research in amoebiasis has concentrated on two subjects: 1. the dual manifestation of the infection as harmless colonization of the intestinal cavity or pathogenic tissue invasion and 2. the molecular analysis of functions of e. histolytica that are considered essential for pathogenicity. besides epidemiological studies and isoenzyme analyses, molecular genetics have revealed additional evidence that two genet ... | 1992 | 1452192 |
| use of a recombinant 170-kilodalton surface antigen of entamoeba histolytica for serodiagnosis of amebiasis and identification of immunodominant domains of the native molecule. | we expressed the gene that encodes one of the major surface antigens of entamoeba histolytica, the 170-kda protein (1,270 amino acids), as a glutathione s-transferase fusion protein containing amino acids 1 to 1202 (lacking the putative transmembrane and cytoplasmic regions) and as separate fusion proteins containing each of three major domains of the 170-kda molecule. lysates from bacteria induced to express one of these proteins were used as the target antigens in a western blot (immunoblot) a ... | 1992 | 1452647 |
| a monoclonal antibody for distinction of invasive and noninvasive clinical isolates of entamoeba histolytica. | approximately 10% of the world population is infected with entamoeba histolytica, but only 10% of the carriers develop symptomatic amebiasis. this discrepancy could be explained by the genotypic differences between the morphologically indistinguishable invasive and noninvasive strains of e. histolytica currently identified by zymodeme analysis, a technique that is unsuitable for routine diagnostic laboratories. here we report the production of a monoclonal antibody against e. histolytica and its ... | 1992 | 1452651 |
| sensitive and specific serodiagnosis of invasive amebiasis by using a recombinant surface protein of pathogenic entamoeba histolytica. | a recombinantly expressed protein, receh-p1, representing part of an immunodominant surface antigen of pathogenic entamoeba histolytica, was used for serodiagnosis of invasive amebiasis. expression was performed under the control of a t7-rna promoter by using a modified procaryotic expression vector, designated phist7. this vector allowed high-yield expression of receh-p1 fused to a stretch of sequence containing eight histidine residues, which facilitated purification by metal chelate affinity ... | 1992 | 1452699 |
| the enzymeba test: detection of intestinal entamoeba histolytica infection by immuno-enzymatic detection of histolysain. | we describe a new, improved test for the detection of intestinal infection by entamoeba histolytica. the test depends upon immunoadsorption of the e. histolytica cysteine proteinase, histolysain, from faecal samples, and subsequent visual detection of the enzyme by a colour reaction. with samples from 200 volunteers, results agreed closely with those obtained by the conventional microscopic technique, and there were no false positive reactions with samples containing other parasites. the test is ... | 1992 | 1454418 |
| circulating antibodies to histolysain, the major cysteine proteinase of entamoeba histolytica, in amoebic liver abscess patients. | a solid-phase enzyme immunoassay (eia) was used to detect circulating antibodies to histolysain, the major cysteine proteinase of entamoeba histolytica. serum samples from 40 healthy controls, 33 asymptomatic e. histolytica cyst passers and 22 patients with amoebic liver abscess were tested. antibodies to histolysain were found in 72.7% of cases of amoebic liver abscess, 18.1% of the cyst passers and 2.5% of healthy controls, which suggests that a humoral immune response is induced by histolysai ... | 1992 | 1454419 |
| systemic manifestations of invasive amebiasis. | eighty-four patients with serious infection due to entamoeba histolytica were evaluated for systemic complications by objective criteria for dysfunction of the organ systems normally assessed in surgical sepsis. of 71 patients with amebic liver abscess (ala), 41% had systemic complications and 13% had more than one organ system involved. patients > or = 40 years of age and those being treated with steroids were at significantly increased risk of developing complications (p < or = .05). the eryth ... | 1992 | 1457670 |
| purification and biochemical properties of calmodulin in entamoeba histolytica and its distribution during secretion of electron-dense granules. | 1. calmodulin (cam) was detected during secretion of electron-dense granules by entamoeba histolytica trophozoites with immunofluorescence. 2. it was purified to apparent homogeneity by chromatography with a yield of 2.26 micrograms of calmodulin/mg of protozoan protein. purity was established by gel electrophoresis. 3. the parasite calmodulin has properties characteristic of calmodulin isolated from other eukaryotes: an apparent molecular weight of 19 or 17 kda in presence of egta or cacl2, res ... | 1992 | 1458827 |
| role of pure and biologically active amoebal rna in assessment of lymphokines: a report of 55 ala cases. | amoebic liver abscess cases (55) were assessed for release of lymphokines (lmif) using pure and biologically active amoebal rna of axenic entamoeba histolytica (nih: 200) obtained with cesium chloride centrifugation. lymphokines released by t lymphocytes in response to both amoebal rna and whole amoebic lysate (wal) were tested by leukocyte migration inhibition test (lmit) on blood samples from amoebic liver abscess cases. a significant increase was observed in the release of lymphokine and 100% ... | 1992 | 1459655 |
| a severe combined immunodeficient (scid) mouse model for infection with entamoeba histolytica. | we used severe combined immunodeficient (scid) mice to study resistance to invasive infection with entamoeba histolytica. seven of seven scid mice developed liver abscesses when challenged intrahepatically with virulent hm1:imss strain e. histolytica trophozoites. only one of seven similarly challenged immunocompetent congenic c.b-17 mice developed an abscess. adoptive transfer of polyclonal rabbit anti-e. histolytica antiserum, but not preimmune rabbit serum, completely protected 7 of 12 scid m ... | 1992 | 1460420 |
| evaluating measures to control intestinal parasitic infections. | intestinal parasitic infections are among the most common infections of humans in developing countries, but the resources available for their control are severely limited. careful evaluation of control measures is essential to ensure that they are cost-effective. the evaluation of the effects of control on intestinal helminths and intestinal protozoa requires an understanding of the different epidemiological patterns of these two groups of parasites. the transmission dynamics and morbidity assoc ... | 1992 | 1462652 |
| prevalence of entamoeba histolytica and other intestinal parasites in a community from maracaibo, venezuela. | the prevalences of entamoeba histolytica and other intestinal parasites were assessed in a suburban community of maracaibo, venezuela, by examination of a stool specimen from each of 342 individuals, using iron-haematoxylin stained faecal smears and formalin-ether concentration. the overall parasitic infection rate was 80.4%, and 65.8% of the population had multiple infections. the overall amoebic infection rate, which was highest in female adults, averaged 39.7%. the e. histolytica infection ra ... | 1992 | 1463357 |
| primary pulmonary amoebiasis--an unusual cause of pulmonary consolidation. | | 1992 | 1469769 |
| the destruction of virulent entamoeba histolytica by activated human eosinophils. | unlike normal (i.e., non-activated) human eosinophils that are unable to destroy virulent entamoeba histolytica even in the presence of antibodies and complement, activated eosinophils effectively destroy the parasite in vitro without the help of opsonins, yet increase this capacity with their assistance. many activated eosinophils succumb in the process as well, probably victims of toxic products released by dying amoebae. human activated eosinophils thus behave more like activated macrophages ... | 1992 | 1470477 |
| use of an enzyme-linked immunosorbent assay to detect anti-adherence protein antibodies in sera of patients with invasive amebiasis in cairo, egypt. | we used enzyme-linked immunosorbent assay (elisa) to detect igg antibodies to the entamoeba histolytica galactose-inhibitable adherence protein in the sera of 50 uninfected controls, 50 cases with asymptomatic cyst passage, 100 patients with amebic colitis, and six patients with amebic liver abscess from cairo, egypt, and in 50 healthy controls from the united states. when the mean + 3 sd value above that of the controls from the united states was used as a criterion for a positive elisa result, ... | 1992 | 1471737 |
| identification and partial characterization of a lipophosphoglycan from a pathogenic strain of entamoeba histolytica. | an acidic glycoconjugate could be extracted from a delipidated residue fraction of [3h]galactose, [3h]mannose or [32p]orthophosphate metabolically labeled entamoeba histolytica with water/ethanol/diethylether/pyridine/nh4oh (15:15:5:1:0.017). the radioactively labeled glycoconjugate comprised 50-55% of the total [3h]galactose label incorporated into macromolecules. sodium dodecyl sulfate polyacrylamide gel electrophoresis of the radiolabeled glycoconjugate showed two diffuse smears centering aro ... | 1992 | 1474994 |
| evaluation of new anti-infective drugs for the treatment of diarrhea caused by entamoeba histolytica. infectious diseases society of america and the food and drug administration. | entamoeba histolytica causes colonic infection that ranges from asymptomatic carriage to invasive disease with infection of extraintestinal organs, particularly the liver. the disease occurs in both sporadic and epidemic forms. diagnosis requires visualization of trophozoites or cysts by microscopic examination of stool, colonic scrapings, or biopsy specimens. patients with either asymptomatic or symptomatic disease may be eligible for clinical trials. a prospective, randomized, double-blind, pl ... | 1992 | 1477239 |
| linkage between actin and ribosomal protein l21 genes in entamoeba histolytica. | | 1992 | 1484554 |
| non-pathogenic entamoeba histolytica in italian hiv-infected homosexuals. | a cohort of 51 homosexuals who were either hiv-positive or had aids was followed prospectively with parasitologic stool examination and in vitro culture in order to determine the incidence of e. histolytica infection. amoebic isolates were further characterized by electrophoretic isoenzyme study. five subjects (9.8%) were found to be infected with e. histolytica. none of the amoebic isolates were found to be pathogenic by isoenzyme analysis. | 1992 | 1486238 |
| detection of pathogenic entamoeba histolytica dna in liver abscess fluid by polymerase chain reaction. | a sensitive method for detection of pathogenic entamoeba histolytica dna in drained fluids from liver abscess patients, using the polymerase chain reaction (pcr), has been developed. the pcr employs oligonucleotide primers specific for the gene encoding the 30 kda molecule of pathogenic e. histolytica. liver abscess fluids (19 samples), from 14 patients with a presumptive amebic liver abscess, were examined microscopically and by the pcr method. only two of the 19 samples were positive microscop ... | 1992 | 1487381 |
| v-atpases of the plasma membrane. | v-atpases reside in high densities on the plasma membrane in specialized types of insect and vertebrate cells. they provide unique biochemical and electrophysiological properties that allow them to function in energizing the plasma membrane in insects, and in cellular acid excretion in vertebrates. | 1992 | 1491228 |
| ion transport in parasitic protozoa. | many parasitic protozoa go through complex life cycles in the course of which they adapt to widely different environments; ion transport processes are expected to play a role both in pathogenicity and in adaptation. so far, studies on ion transport have been virtually limited to leishmania, plasmodium and entamoeba. the distribution of ion pumps in the former two organisms generally appears to conform to the picture established for other protozoa, i.e. a proton-motive p-atpase in the plasma memb ... | 1992 | 1491229 |
| [a case of focal necrotizing granulomatous hepatitis in childhood]. | granulomatous hepatitis make up a group of conditions of various aetiologies. the diagnosis of granulomatous hepatitis is histologic, since the aspect of the granulomatous lesion is not always indicative of a specific disease. it is important to take into consideration for the aetiologic diagnosis a good response to a specific therapy or the execution of complementary examinations. the 25% of granulomatous hepatitis remain undiagnosed. | 1992 | 1491892 |
| amoebic psoas and liver abscesses. | a 28 year old woman with a history of a dysenteric illness and documented campylobacter infection presented with amoebic psoas and liver abscesses. a review of the literature of the last 20 years did not yield any reports of an amoebic psoas abscess. | 1992 | 1494528 |
| analysis of pathogenicity by restriction-endonuclease digestion of amplified genomic dna of entamoeba histolytica isolated in pernambuco, brazil. | the pathogenicity of 47 strains of entamoeba histolytica isolated in pernambuco, brazil, was examined using the polymerase chain reaction (pcr) followed by restriction-endonuclease digestion. electrophoretic patterns of pcr products digested with hinfi revealed that all strains were nonpathogenic. the results were entirely in accord with phenotypic properties such as isoenzyme patterns and the failure to bind a pathogenic-isolate-specific monoclonal antibody. when the sensitivity of pcr was exam ... | 1992 | 1495923 |
| parasitological and microbiological evaluation of mixe indian medicinal plants (mexico). | medicinal plants are an important health resource in many regions of the americas and are of particular importance to many indian communities. based on a recent ethnobotanical study in mexico, we investigated the activity of 29 plant extracts against entamoeba histolytica, three bacteria (bacillus subtilis, escherichia coli, and micrococcus luteus) and two fungi (cladosporium cucumerinum and penicillium oxalicum). after separation of these extracts between ch2cl2 and h2o the resulting phases wer ... | 1992 | 1501496 |
| sulfate metabolism in entamoeba histolytica. | sulfate fluxes and sulfate metabolites in entamoeba histolytica were characterized employing [35s]sulfate as a marker. sulfate was taken up both across the plasma membrane and by pinocytosis; in growth medium (sulfate concentration, 1.1 mm) total uptake was 1.5 mumol h-1 (5 x 10(7) cells)-1. the fate of sulfate within the cells was investigated by thin-layer chromatography. major metabolites (together greater than 3 mumol (5 x 10(7) cells)-1) were monoethyl sulfate and 3-cholesteryl sulfate; bot ... | 1992 | 1501646 |
| [management of patients with traveler's diarrhea]. | traveler's diarrhea starts 5 to 15 days after arrival with 3 or more watery bowel movements daily in 4 to more than 50% of travelers depending on geographical regions. enterotoxin producing strains of e. coli are isolated in 20 to 50% of patients, followed by shigella, salmonella, campylobacter and vibrio spp. rarely giardia lamblia, entamoeba histolytica and cryptosporidia are causative organisms. the cornerstone of treatment is oral rehydration. the efficacy of anti-diarrhetics is not convinci ... | 1992 | 1509861 |
| molecular cloning and characterization of onchocystatin, a cysteine proteinase inhibitor of onchocerca volvulus. | a cdna clone designated ov7 encodes a polypeptide that corresponds to a highly antigenic onchocerca volvulus protein. ov7 has significant amino acid sequence homology to the cystatin superfamily of cysteine proteinase inhibitors. in this report we establish that the ov7 recombinant protein is active as a cysteine proteinase inhibitor, and we have named it onchocystatin. it contains a cystatin-like domain that inhibits the activity of cysteine proteinases at physiological concentrations. recombin ... | 1992 | 1512269 |
| chronic proctitis due to entamoeba histolytica. | | 1992 | 1514541 |
| mapping and partial sequencing of the genes coding for two different cysteine proteinases in pathogenic entamoeba histolytica. | | 1992 | 1518524 |
| a second short repeat sequence detected downstream of rrna genes in the entamoeba histolytica rdna episome. | | 1992 | 1518536 |
| diloxanide furoate for treating asymptomatic entamoeba histolytica cyst passers: 14 years' experience in the united states. | diloxanide furoate is used for treating asymptomatic or mildly symptomatic persons who are passing cysts of entamoeba histolytica. the centers for disease control (atlanta) released this drug for 4,371 treatment courses from 1977 through 1990. of the 2,815 report forms (64%) returned, 656 adverse effects were reported for 390 treatment courses (14%); they included flatulence (260), diarrhea or cramping (100), nausea (93), headache (17), disorientation or dizziness (9), and diplopia (4). during 1 ... | 1992 | 1520794 |
| [interaction of the cytoskeleton of e. histolytica with human erythrocytes]. | the mechanism by which trophozoites of e histolytica destroy mammalian cells has been correlated with the polymerization of the actin contained in the amoeba's cytoskeleton. this is preceded by the attachment of the amoeba lectins with carbohydrates in the cell surface. here we describe the events of the interaction of e histolytica cytoskeleton with human red blood cells using fluorescence microscopy of glutaraldehyde-fixed trophozoites membrane removed with triton x-100 and stained with rhodam ... | 1992 | 1523355 |
| identification of blastocystis hominis by colonic brush cytology. a case report. | blastocystis hominis is a unicellular organism the pathogenic potential of which in humans remains unclear. it may be identified during a workup for gastrointestinal symptoms, usually in stool examined for ova and parasites. we describe a case in which b hominis was identified by cytologic examination in a patient with crohn's disease who underwent colonoscopy and brushing of a transverse colon stricture. the morphologic features of this organism are described and contrasted with those of the un ... | 1992 | 1523938 |
| variations in isoenzymes of cloned & uncloned axenic entamoeba histolytica without bacterial association. | five clones of axenic e. histolytica (hmi) grown as discrete colonies in semisolid agar medium were adapted in liquid medium and labelled as hmi-c121, hmi-c131, hmi-c143, hmi-c144 and hmi-c145. isoenzymes of these 5 clones of e. histolytica (hmi) were investigated in starch gel electrophoresis. there were no differences in the electromobility of maleate nadp oxidoreductase and glucosephosphoisomerase amongst the five clones and uncloned cultures of axenic e. histolytica. the relative electromobi ... | 1992 | 1534784 |
| influence of intestinal parasitism on lactose absorption in well-nourished african children. | hydrogen breath tests were performed in gabon (central africa) after a loading dose of lactose in 67 well-nourished african children (50 with intestinal parasites and 17 unparasitized) and in 18 unparasitized young adults. all had normal nutritional status, and none had diarrhea or digestive symptoms. parasites that were found included ascaris lumbricoides in 76% of the parasitized children, trichuris trichiura in 58%, giardia in 24%, entamoeba histolytica in 20%, schistosoma intercalatum in 16% ... | 1992 | 1539747 |
| isolation and partial characterization of a surface glycoconjugate of entamoeba histolytica. | to study surface molecules of entamoeba histolytica we produced monoclonal antibodies from mice immunized with lysates from the pathogenic amebic strain hm1:imss, and screened them for the ability to inhibit e. histolytica adhesion. one monoclonal antibody, cc 8.6, was a potent inhibitor of amebic adhesion to a chinese hamster ovary cell line, and was capable of inhibiting hm1:imss mediated cytotoxicity by 50%. we found that monoclonal antibody cc 8.6 bound to an amebic glycoconjugate. the glyco ... | 1992 | 1542307 |
| isolation of an entamoeba histolytica cdna clone encoding a protein with a putative zinc finger domain. | | 1992 | 1542313 |
| antiparasitic agents. | in recent years, introduction of new and more effective agents has improved the overall therapy for parasitic infections. this field, however, is still plagued by numerous problems, including the development of resistance to antimicrobial agents (especially with malaria), unavailability of agents in the united states or lack of approval by the food and drug administration, and major toxicities or lack of experience in pregnant women and children, which limits use in these groups of patients. wid ... | 1992 | 1545596 |
| biochemical characterization of rat colonic mucins secreted in response to entamoeba histolytica. | invasion of the colonic mucosa by entamoeba histolytica trophozoites is preceded by colonic mucus depletion. the aim of our studies was to determine whether e. histolytica caused a differential secretion of mucin species in a rat colonic loop model. mucus secretion in response to amoebae was followed by release of acid-precipitable 3h-glucosamine metabolically labelled glycoproteins and in vitro labelling of glycoprotein secretion with nab3h4. the secretory response consisted of high-mr goblet c ... | 1992 | 1548082 |
| modulation of a surface antigen of entamoeba histolytica in response to bacteria. | changes in the cell surface of entamoeba histolytica, a human intestinal parasite and the causative agent of amebic dysentery, were examined with a monoclonal antibody, 2d7.10, which selectively recognizes carbohydrate epitopes in some axenic amebic strains. while high-level expression of this epitope was observed in axenic amebae, it was either absent or present only in small amounts in xenic amebae. furthermore, reassociation of the axenic amebae with intestinal flora resulted in loss of the 2 ... | 1992 | 1548096 |
| indigenous invasive amoebiasis in australia. | amoebic liver abscess can occur in patients who have never travelled outside australia. a case is reported to reinforce that entamoeba histolytica should be considered in the differential diagnosis of all patients presenting with liver abscess, whether they have travelled abroad or not. | 1992 | 1550509 |
| amebiasis: an update. | although amebiasis is often considered a disease of developing countries, it is an important public health problem throughout the world. at least 90% of infected patients are asymptomatic, but the remainder may present with clinical syndromes ranging from frank dysentery to abscesses of the liver, lungs, or brain. the most common challenge for physicians in developed countries is treating infection due to entamoeba histolytica in an asymptomatic patient or determining its clinical significance i ... | 1992 | 1554822 |
| amebic colitis in inflammatory bowel disease. | | 1992 | 1556420 |
| lysis of pathogenic and nonpathogenic entamoeba histolytica by human complement: methodological analysis. | the effect of nonimmune human serum on entamoeba histolytica trophozoites was studied: (a) using whole serum in the presence of ca and mg ions allowing complement activation via both the alternative and classical pathways or in the presence of mgegta permitting alternative pathway activation only; (b) using different e. histolytica isolates; (c) varying serum and trophozoite concentrations and the time of incubation; and (d) using three different methods to quantify lysis, i.e., microscopic insp ... | 1992 | 1557228 |
| human t-lymphocyte proliferation, lymphokine production, and amebicidal activity elicited by the galactose-inhibitable adherence protein of entamoeba histolytica. | we studied human t-lymphocyte responses to the purified entamoeba histolytica galactose-inhibitable adherence protein. individuals having serum anti-adherence protein antibodies possess peripheral blood lymphocytes which demonstrate antigen-specific responses to the purified adherence protein (10 micrograms/ml) and whole soluble amebic antigen (100 micrograms/ml). this was determined by incorporation of [3h]thymidine (53,080 and 73,114 dpm, respectively) and by increased production of interleuki ... | 1992 | 1563804 |
| ischemia in experimental acute amebic liver abscess in hamsters. | in experimental acute amebic liver abscess, produced in hamsters by the intraportal inoculation of 1 x 10(6) axenic trophozoites of entamoeba histolytica strain hm-1, we examined the blood perfusion of the lesions 5, 10, 24 and 72 h after injection of the parasites. india ink introduced into the portal circulation filled all liver vessels but was systematically excluded from even the earlier amebic lesions. the absence of serum proteinase inhibitors from the lesions may allow the participation o ... | 1992 | 1563915 |
| characterization of a repetitive dna element from entamoeba histolytica. | | 1992 | 1565133 |
| age-specific sero-prevalence of amoebiasis and giardiasis in southern indian infants and children. | the age-specific sero-prevalence of amoebiasis and giardiasis was estimated in 91 pediatric diarrhoea and in 70 non-diarrhoeal cases from southern india. anti-amoeba/giardia igg assays on 20 children with inflammatory bowel disease from the uk yielded base-line levels in a non-endemic symptomatic population. igg, igm, and iga levels were estimated to e. histolytica and g. lamblia using an elisa. concomittant faecal examinations were done for the indian children. there was a significant correlati ... | 1992 | 1569636 |
| asymptomatic intestinal colonization by pathogenic entamoeba histolytica in amebic liver abscess: prevalence, response to therapy, and pathogenic potential. | since the application of isoenzyme electrophoresis to the study of entamoeba histolytica, the prevalence and natural history of asymptomatic intestinal colonization in patients with amebic liver abscess (ala) has not been addressed. we prospectively evaluated this enteric phase in 50 patients with ala, using two dosage regimens of metronidazole. the overall prevalence of asymptomatic colonization was 72% (36/50). all these isolates, without exception, proved to express pathogenic zymodemes. desp ... | 1992 | 1576284 |
| characterization of the galactose-specific binding activity of a purified soluble entamoeba histolytica adherence lectin. | we studied galactose (gal)-specific binding of the soluble purified 260-kda entamoeba histolytica adherence protein to glycosylation deficient chinese hamster ovary (cho) cell mutants. our goal was to further define the lectin's functional activity and carbohydrate receptor specificity. the adherence protein was purified by acid elution from an immunoaffinity column; however, exposure of the surface membrane lectin on viable trophozoites to identical acid ph conditions had no effect on carbohydr ... | 1992 | 1578406 |
| an experimental model of ameboma in guinea pig. | among the wide variety of clinicopathological manifestations of intestinal amebiasis, amebomas occur rarely and their pathogenesis is not well understood. when cholesterol-fed, 2- to 4-week-old guinea pigs were infected intracecally with a virulent, monoaxenic strain of entamoeba histolytica, gross and histologically characteristic amebomas developed in 85% of the animals by the 3rd day, in 94% by the 9th day, and in 96% by the 12th day postinfection, by which time most of them had died. ameboma ... | 1992 | 1582480 |
| entamoeba histolytica: is conversion of "nonpathogenic" amebae to the "pathogenic" form a real phenomenon? | entamoeba histolytica isolates have been shown to fall into two groups based on isoenzyme analysis. these groupings ("pathogenic" and "nonpathogenic") correlate well with the clinical course of the infection. a controversy exists over whether isoenzyme patterns are stable or whether under certain circumstances an isolate can convert from one form to the other. resolution of this uncertainty is of importance since the nonpathogenic pattern has never been observed in amebae isolated from cases of ... | 1992 | 1582483 |
| outbreak of entamoeba histolytica and giardia lamblia infections in travellers returning from the tropics. | of 160 travellers from various regions in italy who had taken part in a five-day organized trip to phuket, thailand, and been accommodated in the same luxury hotel, 17 showed either amebic abscess or colitis. a pretested questionnaire that focused on the consumption of foods and beverages well known to be a source of intestinal infection in endemic areas was available from these 17 patients as well as from 41 out of 74 asymptomatic travellers. stool samples for parasitological examination were a ... | 1992 | 1582688 |
| codon usage in pathogenic entamoeba histolytica. | | 1992 | 1588599 |
| immediate deterioration of rabbit colon preparations by entamoeba histolytica trophozoite lysates. | | 1992 | 1589435 |
| ribosomal dna sequences in the differentiation of pathogenic and non-pathogenic isolates of entamoeba histolytica. | recombinant ribosomal dna sequences were amplified by pcr and used as probes to perform a fingerprint analysis of total dna from different entamoeba histolytica isolates. rflps obtained with one of the probes, r-1, support previous proposals that pathogenic and non-pathogenic e. histolytica are closely related, yet genotypically distinct. another probe, r-2, while not distinguishing between the two forms of e. hystolytica, was able to differentiate between them and e. moshkovskii, which has morp ... | 1992 | 1594290 |
| target cell deformability determines the type of phagocytic mechanism used by entamoeba histolytica-like, laredo strain. | morphological study of red blood cell phagocytosis by entamoeba histolytica-like (laredo strain) has shown that this amoeba is able to ingest by two distinct mechanisms. one is classical phagocytosis and the other is by suction or microphagocytosis. rigidification of red blood cells by treatment with glutaraldehyde shows that there is a correlation between the deformability of the ingested cell and the type of phagocytosis observed. indeed, as the red cells become more rigid, less microphagocyto ... | 1992 | 1596641 |
| necrotic colitis associated with entamoeba histolytica infection in a cat. | a 3-year-old persian cat developed bloody diarrhoea. on histological examination, a marked necrotic colitis with a large number of invading protozoan parasites was observed. the protozoan was identified as entamoeba histolytica by light and electron microscopy. this is the first report describing spontaneous amoebiasis in cats. | 1992 | 1597535 |
| activated mouse macrophages kill entamoeba histolytica trophozoites by releasing reactive nitrogen intermediates. | mouse macrophages activated by gamma interferon (ifn-gamma) and bacterial lipopolysaccharide (lps) are highly cytotoxic for the enteric protozoan parasite entamoeba histolytica. herein, we show that this killing by activated macrophages is l-arginine dependent, inasmuch as it was blocked by exogenous arginase or ng-monomethyl-l-arginine. these two inhibitors had no effect on e. histolytica cytolytic activity against l929 fibroblasts. also, macrophage killing of e. histolytica always correlated w ... | 1992 | 1614330 |
| [entamoeba histolytica: a standing threat]. | the importance and limitations of microscopic differential diagnosis of entamoeba histolytica in asymptomatic carriers is reviewed. the possibility that some nonpathogenic strains of e. histolytica could be entamoeba hartmanni is discussed. the imperative necessity to encourage research in epidemiology and diagnosis is emphasized. the need to know the prevalence in mexico and distinguish e. histolytica from e. hartmanni is also discussed. this differential diagnosis is fundamental in the treatme ... | 1992 | 1615351 |
| amebiasis complicating carcinomas: a diagnostic dilemma. | two black african women and one black american man had carcinomas of cervix, perineum, and sigmoid colon, respectively. in each of these patients, trophozoites of entamoeba histolytica had invaded the surface of the tumor, and in some areas had invaded more deeply into the stroma between the tumor cells. although it is well known that cutaneous amebiasis of anus, penis, vulva, and cervix can mimic squamous cell carcinoma, it may be, perhaps, less well known that carcinomas at these sites may be ... | 1992 | 1621901 |
| cloning and sequence analysis of a calcium-binding protein gene from a pathogenic strain of entamoeba histolytica. | | 1992 | 1625702 |
| [antibodies against entamoeba histolytica in the mexican republic. 1974]. | | 1992 | 1631737 |
| entamoeba histolytica alters arachidonic acid metabolism in macrophages in vitro and in vivo. | entamoeba histolytica infections are associated with a state of transient suppression of cell-mediated immunity. macrophages, the most important cells in host defence and control of invasive amoebiasis, in infected animals have been found to be deficient in effector functions and accessory cell potential. however, little is known of the cellular mechanisms responsible for the down-regulation. this study investigated whether macrophage dysfunction in amoebiasis is associated with altered macropha ... | 1992 | 1634248 |
| modulation of tumor necrosis factor production by macrophages in entamoeba histolytica infection. | the macrophage-derived mediator tumor necrosis factor alpha (tnf) is a cytokine with pleiotropic effects. tnf exhibits potent immunologic and inflammatory properties in parasitic diseases. the present study examined the production of tnf by macrophages isolated from gerbils infected with entamoeba histolytica and by naive macrophages in response to amoebae in vitro. amoebic liver abscess-derived macrophages produced low constitutive basal levels of tnf; in response to lipopolysaccharide (lps) st ... | 1992 | 1639488 |
| codon usage in entamoeba histolytica. | the codon usage of 10 e. histolytica genes comprising 4455 codons was analysed. the codon usage revealed an extremely biased use of synonymous codons with a preference for nnu (44%) and nna (41.4%) codons. codons cgg (arg), agg (arg) and ccg (pro) were absent in the e. histolytica genes examined. the codon usage of e. histolytica resembled that of plasmodium falciparum. | 1992 | 1639575 |
| the role of mannose in the receptor of the monocyte locomotion inhibitory factor produced by entamoeba histolytica. | the effect of the monocyte locomotion inhibitory factor (mlif) produced by entamoeba histolytica is diminished, if not cancelled, when human monocytes are pre-exposed to concanavalin a or sodium periodate, respectively, but not when mlif is pretreated with sodium periodate. when the mlif-inhibited monocyte locomotion assays were performed in the presence of 12 different carbohydrates, only the runs containing d-mannose, 4-o-beta-galactosyl-mannoside or mannan revealed a significant reduction in ... | 1991 | 1653955 |
| [isolation of enteropathogenic microorganism from patients with infection of the digestive tract during 1976 to 1988 in tenri hospital]. | enteropathogenic microorganisms isolated from feces of 9,393 patients with diarrhea or enteritis in our hospital between 1976 and 1988 were analyzed. as the result of the examination of 5,443 outpatients, 1,811 strains of pathogens were isolated from 1,686 cases (31.0%). several species including salmonella spp., escherichia coli serotype, vibrio parahaemolyticus, were isolated before 1978, and the incidence of pathogens was low (14.8%). for the 10-year period since 1979, the incidence markedly ... | 1991 | 1655921 |
| possible role of calmodulin in the secretion of entamoeba histolytica electron-dense granules containing collagenase. | entamoeba histolytica cells secrete electron-dense granules (edgs) that have collagenase activity. to study the possible involvement of calmodulin (cam) on edg secretion, the effect of several cam antagonists (tfp, r24571, w-7, w-5, dibucaine and dl-propranolol) was tested on this cellular function. except for w-5 and dibucaine, the rest of these compounds inhibited edg secretion. transmission electron microscopy of collagen-activated trophozoites showed numerous edgs located in or near the surf ... | 1991 | 1658540 |
| characterization of calcium channel forming activity of entamoeba histolytica in model biological membranes. | entamoeba histolytica is an invasive enteric protozoan parasite whose cytolytic activity is associated with irreversible increases in target cell intracellular calcium. we studied the effect of homogenates of virulent e. histolytica on calcium permeability of bovine chromaffin granules and rat liver mitochondria, model membrane systems whose mechanisms of ion transport and permeability are well characterized. treatment of chromaffin granules, with an extract of e. histolytica resulted in a dose- ... | 1991 | 1661350 |
| inhibition of antibody producing cells (pfc) from peyer patches by glycoproteins from entamoeba histolytica. | it is well known that entamoeba histolytica can cause damage to its host by means of enzymes, cytotoxins and perforins that affect different types of cells. in this work we investigated the effect of different entamoeba histolytica trophozoites products over the secretion of antibodies by mice peyer's patches using a reverse hemolytic assay. results showed that amoebic glycoproteins inhibited the secretion of antibodies by lymphocytes from mice peyer's patches. in all cases the decrease in antib ... | 1991 | 1670482 |
| intestinal parasitic infections in schoolchildren of abha (asir), saudi arabia. | stool specimens from 1282 children between the age of 5 and 13 years attending 10 primary schools for boys in the city of abha, southwestern saudi arabia, were examined for the presence of intestinal parasites. of these, 313, (24.4%) were found infected with one or more species of 11 intestinal protozoa and helminths. the most common pathogenic protozoa being giardia lamblia (10.9%) followed by entamoeba histolytica (4.1%). the nonpathogenic protozoan, entamoeba coli had the highest prevalence r ... | 1991 | 1671621 |
| differentiation of pathogenic from nonpathogenic entamoeba histolytica by restriction fragment analysis of a single gene amplified in vitro. | we previously reported the identification of homologous cdna clones derived from a pathogenic isolate and a nonpathogenic isolate of entamoeba histolytica, which had been designated ceh-p1 and ceh-np1, respectively. sequence analysis of both clones had revealed 10% nucleic acid substitutions, which were dispersed over the entire sequence. this genetic difference had been found to be conserved between all four pathogenic and all five nonpathogenic laboratory strains of e. histolytica tested. on t ... | 1991 | 1672533 |
| the laredo strain and other 'entamoeba histolytica-like' amoebae are entamoeba moshkovskii. | a small number of entamoeba isolates from humans, the best known of which is the 'laredo' strain, have the ability to grow at room temperature. this peculiarity, along with other characteristics, distinguishes the strains from the human pathogen e. histolytica despite their being morphologically inseparable. in contrast, these 'e. histolytica-like' strains share several features with e. moshkovskii, which is most frequently isolated from polluted water. to examine the taxonomic relationships amo ... | 1991 | 1677159 |
| studies on antiparasitic agents: effect of the lactam nucleus substitution in the 2-position on the in-vitro activity of new 5-nitroimidazoles. | the in-vitro antiprotozoal activity of a series of new 5-nitroimidazoles substituted in the 2-position via a lactam nucleus was studied. all these compounds exhibited a better effect than metronidazole and structure-activity relationships are discussed. | 1991 | 1682453 |
| application of atp measurement to evaluation of the growth of parasitic protozoa in vitro with a special reference to pneumocystis carinii. | 1. there was a significant correlation between the increase in the number of entamoeba histolytica, trichomonas vaginalis, giardia lamblia and leishmania donovani in culture, and their atp contents determined by luciferase reaction. 2. the similar correlation was also demonstrated between the decreased number of e. histolytica in the presence of an anti-amebic quassinoid and the nucleotide content in vitro. 3. in the case of pneumocystis carinii, the numbers of the organism remained relatively c ... | 1991 | 1685366 |
| ribosomal rna genes of 'pathogenic' and 'nonpathogenic' entamoeba histolytica are distinct. | most infections with entamoeba histolytica are asymptomatic. two forms of the organism can be distinguished biochemically, and this finding has been explained by two distinct hypotheses: (1) there are two morphologically indistinguishable species, one of which causes disease; (2) there is one species which exists in two interconvertible forms, one of which causes disease. knowledge of which hypothesis is correct has major implications for evaluation and treatment of carriers. we have studied the ... | 1991 | 1685555 |
| longitudinal study of young children in kenya: intestinal parasitic infection with special reference to giardia lamblia, its prevalence, incidence and duration, and its association with diarrhoea and with other parasites. | 84 young children from a rural community, nderu, in kenya, were each followed for up to 10 months, from january to november 1987. their ages ranged from 10 to 28 months over the period of study. stools were obtained once a week, as were reports from the mothers about presence of abdominal complaints, including diarrhoea. a total of 2258 stools and 1873 reports were collected. 9 parasites were commonly encountered of which giardia lamblia was the most frequent at 44.7%. the overall estimated numb ... | 1991 | 1686143 |
| use of an amoeba proteus model for in vitro cytotoxicity testing in phytochemical research. application to euphorbia hirta extracts. | amoeba proteus is proposed as a low-cost multi-purpose biochemical tool for screening and standardizing cytotoxic plant extracts with possible application in the laboratories of developing countries. advantages and limitations of this test are examined and different mathematical treatments (probit analysis versus curve fitting to von bertalanffy and hill functions) are investigated. known anti-cancer (doxorubicin, daunorubicin, dacarbazine, 5-fluorouracil) and antiparasitic (emetine, dehydroemet ... | 1991 | 1686625 |
| pathogenic and nonpathogenic strains of entamoeba histolytica can be differentiated by monoclonal antibodies to the galactose-specific adherence lectin. | entamoeba histolytica infection results in either asymptomatic colonization or invasive colitis and liver abscess. e. histolytica isolates from patients with invasive disease have characteristic isoenzyme profiles (pathogenic zymodemes), suggesting a role for parasite factors in determining the severity of infection. a galactose-specific cell surface lectin from a pathogenic zymodeme was shown to mediate in vitro adherence to human colonic mucins and contact-dependent killing of target cells. si ... | 1990 | 1692809 |
| monoclonal antibodies directed against the galactose-binding lectin of entamoeba histolytica enhance adherence. | the entamoeba histolytica galactose-binding lectin is a surface glycoprotein composed of 170- and 35-kda subunits. inhibition of this lectin with galactose or anti-170 kda subunit polyclonal antibody blocks amebic adherence to target cells and colonic mucin glycoproteins. we describe the properties of 10 mab with specificity for the 170-kda subunit. based on competitive binding studies, six nonoverlapping antigenic determinants on the lectin were identified. the effect of the mab on adherence of ... | 1990 | 1693641 |
| [molecular biology in the differentiation between pathogenic and apathogenic isolates of entamoeba histolytica]. | | 1990 | 1694369 |