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pathogenesis of acute experimental amebic liver abscess in hamsters.the hypothesis was tested that tissue necrosis in acute experimental amebic liver abscess in hamsters is not caused directly by the parasite but rather, indirectly, by the destruction of closely surrounding leukocytes that release their lysosomal enzymes and damage neighboring liver cells. axenically grown trophozoites of entamoeba histolytica strain hm-1 were injected intraportally into normal, hypocomplementemic, and leukopenic hamsters, and the lesions were studied histologically 2, 5, 10, an ...19911779303
results of testing for intestinal parasites by state diagnostic laboratories, united states, 1987.we analyzed results of 216,275 stool specimens examined by the state diagnostic laboratories in 1987; parasites were found in 20.1%. percentages were highest for protozoans: giardia lamblia (7.2%), entamoeba coli and endolimax nana (4.2% each), blastocystis hominis (2.6%), entamoeba histolytica (0.9%), and cryptosporidium species (0.2%). identifications of giardia lamblia increased broadly from the 4.0% average found in 1979, with 40 states reporting increases and seven decreases. most states th ...19911779956
entamoeba histolytica and airline personnel. 19911781018
in vitro study of different antiamoebic drugs. 19911788314
in vitro evaluation of gossypol as potential antiamoebic drug. 19911788315
homologous cysteine proteinases of pathogenic and nonpathogenic entamoeba histolytica. differences in structure and expression.a cdna clone derived from the gene encoding a cysteine proteinase of pathogenic entamoeba histolytica was isolated using an antiserum to the purified enzyme. this clone was used to identify the homologous clone in a cdna library from nonpathogenic e. histolytica. sequence analysis and comparison of the predicted amino acid sequences revealed a sequence divergence of 16%. southern blot analyses indicated that (i) pathogenic isolates may contain more genes coding for these or related enzymes than ...19911705935
specificity of commercially available entamoeba histolytica antigen in enzyme-linked immunosorbent assay (elisa) to sera from dogs with various parasitic infections. 19911718445
reactivity of monoclonal antibodies to species-specific antigens of entamoeba histolytica.twenty monoclonal antibodies were produced against trophozoites of entamoeba histolytica strains hk-9 and hm-1: imss. when reactivity to various enteric protozoa was examined by an indirect fluorescence antibody test, 15 of the monoclonal antibodies were strongly reactive with e. histolytica trophozoites. species-specific antigens recognized by these monoclonal antibodies were located on the plasma membrane, nucleus, cytoplasm, and cytoskeletal structures of the trophozoites. two of the remainin ...19911724012
laboratory diagnosis of amebiasis.the procedure used to diagnose amebiasis varies depending on the geographic location of the laboratory. however, in general, the microscopic diagnosis and differentiation of e. histolytica from other intestinal amebae is most satisfactorily achieved when the specimen is preserved immediately and both a concentration and stained smear are examined. the number of additional positive findings achieved by the cultivation of fecal material does not justify the time and cost involved. on the other han ...19911724953
[diagnostic certainty in intestinal amebiasis in managua].three surveys were carried out in managua. nicaragua. in the first one it was found that 71% of the intestinal amebiasis cases of obligatory notification had no comparable diagnostic foundations; in the second one, 11.7% of the laboratory diagnoses as entamoeba histolytica referred by 4 health centers were correct; and in the third one, it was obvious that only 9.4% of the doctors knew well what intestinal amebiasis is. the results suggest that intestinal amebiasis is being diagnosed excessively ...19911725928
[new aspects of the biology of entamoeba histolytica].to determine the mechanism of mitosis in e. histolytica, a study was carried out with axenic cultures of trophozoites in coplin jars with glass slides to stain them in situ with giemsa and fluorescent antibodies for actin. tobuline and myosin. sedimented amoeba of cultures were used also for ultrastructural studies after glutaraldehyde fixation, and inclusion in spon-araldite. giemsa stained trophozoites showed duplication by budding or fission with production of polykaryons, mononuclei, micronu ...19911790856
down-regulation of murine lymphocyte responsiveness to mitogens after treatment with antigens of entamoeba histolytica.injection of mice with pathogenic entamoeba histolytica (strain hm1-imss) antigens resulted in a decreased capacity of splenocytes to respond to mitogen-induced blastogenesis following a challenge with concanavalin a (con a), phytohemagglutinin (pha), and lipopolysaccharide (lps), whereas no inhibition was observed in mice that had previously been injected with equivalent amounts of non-pathogenic e. histolytica-like laredo antigens. depletion of adherent cells in the splenocyte preparation indi ...19911792226
the plasma membrane of entamoeba histolytica: structure and dynamics.the plasma membrane components of the parasitic protozoan entamoeba histolytica, the causative agent of human invasive amebiasis, have been biochemically and immunologically characterized during the last decade. in addition, genes coding for certain surface proteins have been cloned. in spite of these advances, a unified characterization of plasma membrane antigenic components of the parasite is still required for badly needed advancements in the design of useful diagnostic, epidemiologic, and i ...19911794060
[intestinal parasites in primary school students].five hundred thirty-one stool samples obtained from primary schools. the age range was between 7 and 13 years, 49% of the patients were females an 51% of the patients males. in our study it has been observed that the parasite incidence was 36.9% the predominant parasite was ascaris lumbricoides (12%), giardia intestinalis (9%), hymenolepis nana (7.1%) entamoeba histolytica (6%) and trichuris trichiura (2.6%) respectively, we detected six different parasites in the primary school students because ...19911795661
in vitro effects of berberine sulphate on the growth and structure of entamoeba histolytica, giardia lamblia and trichomonas vaginalis.the plant alkaloid, berberine sulphate, inhibited the growth of entamoeba histolytica, giardia lamblia and trichomonas vaginalis in bi-s-33 medium, and induced morphological changes in the parasites. exposure of e. histolytica to berberine caused a clumping of chromatin in the nucleus, and the formation of autophagic vacuoles and aggregates of small vacuoles in the cytoplasm. in berberine-treated g. lamblia, an irregularly-shaped vacuole appeared in the cytoplasm and gradually enlarged during cu ...19911796883
a study of the bacterial and parasitic causes of acute diarrhoea in northern jordan.the prevalence of bacterial and parasitic diarrhoeagenic agents in 200 patients suffering from acute diarrhoea and reporting to hospitals and health centres in northern jordan, and in controls was determined. one or more bacterial or parasitic enteropathogens was isolated from 79 patients (39.5%). prevalence rates for these pathogens was as follows: enterotoxigenic escherichia coli, 9%; enteropathogenic e. coli, 9%; salmonella spp. 7%; campylobacter spp, 5.5%; yersinia enterocolitica, 4.5%; shig ...19911800560
inhibition of axenically grown entamoeba histolytica by purine nucleoside analogs and actions of natural nucleosides.the effects of the nucleoside analogs tubercidin, nebularin, formycin b and 3'-deoxyinosine on axenically grown entamoeba histolytica were tested. both tubercidin and nebularin showed pronounced inhibitory action, 50% of growth inhibition (ic50) being obtained at 0.14 and 0.82 microm, respectively. formycin b and 3'-deoxyinosine were essentially inactive or weakly active at concentrations above 10 microm. natural nucleosides, including adenosine, inosine, guanosine, thymidine, uridine and cytidi ...19911801136
a modification of diamond's medium for the axenic culture of entamoeba histolytica.the use of casein hydrolysate in diamond's axenic culture medium tps-1 in replacement of trypticase allowed good growth of the trophozoites of entamoeba histolytica. this modified medium also supported growth of trophozoites preserved for 16 months in liquid nitrogen. considerable labour and cost of serum can be saved by using 5% instead of 10% bovine serum in combination with this modified medium.19911801343
enhanced antiparasitic activity of lipophilic tetracyclines: role of uptake.it was previously noted that the inhibitory activities of lipophilic tetracyclines against the growth of giardia lamblia in vitro were up to 40-fold greater than those of nonlipophilic tetracyclines (50% inhibitory concentration [ic50] = 1.8 to 71 micrograms/ml) (t. d. edlind, antimicrob. agents chemother. 33:2144-2145, 1989). we have now extended this observation to trichomonas vaginalis (ic50 = 2.9 to 200 micrograms/ml), entaoeba histolytica (ic50 = 3.8 to 36 micrograms/ml), and leishmania maj ...19911803991
phagocytic capacity of kupffer cells during hepatic amoebiasis in guinea pigs.very few studies have been carried out on the role of liver macrophages (kupffer cells) during the course of hepatic amoebiasis. the kinetics of phagocytic activity of kupffer cells and blood monocytes was studied in guinea pigs intra-mesenterically infested with entamoeba histolytica. the phagocytic capacity of blood monocytes of normal animals was comparatively lower than kupffer cells for both latex and haemolysin coated sheep red blood cells. significant decline in phagocytic response of kup ...19911804871
autochthonous amoebiasis in institutionalized mentally-retarded patients: preliminary evaluation of isoenzyme patterns in three isolates.three autochthonous cases of entamoeba histolytica infection in institutionalized mentally-retarded patients are reported. isoenzyme analysis by starch-gel electrophoresis shows the pathogenicity of the three isolates: two belong to zymodeme ii, and one to zymodeme xix. the study shows that invasive e. histolytica strains occur in italy and can be isolated from institutionalized oligophrenic patients.19911809244
[isoenzymatic characterization of strains of entamoeba histolytica isolated from cuban patients and foreigners from africa].an analysis was made of the isoenzyme patterns of 61 entamoeba histolytica strains: 42 from cuba and 19 from angola mozambique and ghana. by means of these patterns the non-pathogenic nature of the cuban strains (group 1) was shown. it coincided with the clinical characteristics of the infection in the carriers. among the imported strains were 2 samples with pathogenic patterns ii corresponding to 1 dysentery case and to 1 asymptomatic patient, and also non-pathogenic ones (i, ii, iii and xviii) ...19911812535
protective immunity to entamoeba histolytica infection in subjects with antiamoebic antibodies residing in a hyperendemic zone.to investigate the relationship between amoebic gut infection and the presence of serum antiamoebic antibodies in a community where amoebiasis is highly endemic, a cross-sectional population survey was conducted covering 982 subjects in 2 adjacent villages in rural india. e. histolytica was detected in fecal smears in 18.1% (88/487) and antiamoebic antibodies by micro-elisa in 28.7% (251/874) subjects. in 450 subjects in whom there was no clinical evidence of invasive amoebic disease or history ...19911815341
synthesis and study of antiprotozoal activity of some 5-nitrothiophene aldimines.this paper reports on the synthesis and the antiparasitical activity of some 5-nitrothiophene aldimines variously substituted on aniline nucleus. the influence of substituents on the activity of the prepared compounds is discussed.19911815581
detergent dissection of membrane proteins of entamoeba histolytica and its effect on lymphokine release in in vitro.fifty-two amoebic liver abscess cases were assessed for the release of lymphokines (lmif) using detergent dissected membrane proteins (ddmp) of axenic entamoeba histolytica (nih:200) obtained with sodium deoxycholate treatment. lymphokines release by t lymphocytes in response to both ddmp and whole amoebic lysate (wal) was tested by leukocyte migration inhibition test on blood samples from amoebic liver abscess cases. a significant increase was noted in the release of lmif and 100% positivity wa ...19911816085
[3 cases of hematogenous lung abscess of amebic origin].invasive amebiasis is a very serious health problem in mexico as it is presumably related to the presence of virulent strains of entamoeba histolytica and poor hygienic and sanitary conditions; other factors related to invasive amebiasis are undernutrition, alcoholism, and homosexuality. we present three patients with pulmonary amebic hematogenous abscess. clinically all patients had the typical "chocolate" exudate. the three patients had pulmonary consolidations by chest roentgenogram; one of t ...19911818373
invasive amebiasis in a spider monkey (ateles geoffroyi). case report and a short review of the literature of amebiasis in non-human primates.a spider monkey (ateles geoffroyi) studied at the san juan de aragon zoo died with symptoms of amoebic dysentery verified by coprologic investigation of the parasite, his female partner was cured with conventional antiamoebic treatment. at autopsy widespread ulcerations in the colon and multiple liver abscesses were found, containing trophozoites of entamoeba histolytica. both lesions were identical to those observed in human amoebiasis. a short review of the literature in nonhuman primates infe ...19911819979
seroepidemiology of anti-entamoeba histolytica antibody by enzyme-linked immunosorbent assay in the greater tokyo area.an enzyme-linked immunosorbent assay (elisa) for detecting antibody against entamoeba histolytica was used in a survey to determine the prevalence of e. histolytica infection in the greater tokyo area. serum samples were collected from 1,869 randomly chosen, symptom-free volunteers (1,645 males and 224 females). seventeen individuals (0.91%), 14 males and three females, had elisa values that were interpreted as positive. the calculated histogram of the anti-e. histolytica igg values, after logar ...19911820666
experimental fusion of e. histolytica cells by horseradish peroxidase treatment.the experimental fusion of entamoeba histolytica cells after their treatment with horseradish peroxidase is reported. this finding is discussed in relation with the general knowledge about the cell fusion process.19911821166
cytopathogenicity of entamoeba histolytica to human intestinal epithelial cells: inhibition by monoclonal antibodies and sera from amoebic patients.interactions of pathogenic entamoeba histolytica (hm 1) with human intestinal epithelial cells (henle-407) were investigated. the e. histolytica trophozoites adhered and cytolysed 87% of cultured epithelial cell monolayers. a significant (p less than 0.001) inhibition of cytopathic effect of amoebic trophozoites pretreated with monoclonal antibodies to a 29 kda surface associated protein suggested utilization of the 29 kda surface protein in recognition and cytolysis of epithelial target cells. ...19911821426
entamoeba histolytica zymodemes: exhibition of gamma and delta bands only of glucose phosphate isomerase and phosphoglucomutase may be influenced by starch content in the medium.entamoeba histolytica isolated from human can be associated with either symptomatic disease or with asymptomatic carriers. pathogenic and nonpathogenic strains can be distinguished on the basis of differences in the electrophoretic patterns of four isoenzymes (zymodeme). with glucose phosphate isomerase and phosphoglucomutase, we observed variation of the expression of their gamma bands as a function of starch volume in culture. we cultured e. histolytica strains from different zymodemes in robi ...19911825198
[distribution of zymodemes of entamoeba histolytica from different areas of china].using agarose gel electrophoresis, the electrophoretic patterns of four enzymes: malate nadp oxidoreductase (malic enzyme) (me), glucosephosphate isomerase (gpi), phosphoglucomutase (pgm) and hexokinase (hk), were compared and analysed for five strains of entamoeba histolytica, which had been obtained from patients with acute amebic dysentery or asymptomatic cyst carrier in beijing, tianjin and fujian province. the results showed that the electrophoretic patterns of all the five strains of e. hi ...19911829658
[prevalence of intestinal parasitoses in a sample of italian and immigrant workers employed in the food sector of turin].we studied the prevalence of intestinal parasites in a random sample of immigrants and italians employed in the food industry. prevalence ranged from 20.8% among immigrants to 5.6% among italians. where helminths are widespread among indochinese, protozoa are more common among africans. three cases of entamoeba histolytica in asymptomatic subjects were identified and successfully treated. we observed high levels of giardia intestinalis both in italians (2.2%) and immigrants (3.9%). prevalence of ...19911838507
[immune response induced by phosphofructokinase from e. histolytica in hamsters].the enzymatic activity of inorganic pyrophosphate (ppi) dependent phosphofructokinase became manifest in the supernatant obtained by centrifugation in a homogenate of e. histolytica strain hmi-imss at 700,000 g. partial purification of the enzyme was achieved by column chromatography with ultrogel aca-34. ten protein elution spikes were obtained: five showed enzymatic activity. elution spikes i and ii attained the highest values of specific enzymatic activity 6.45 and 6.98 u/mg of protein, respe ...19911840160
immunogenicity of detergent membrane proteins of entamoeba histolytica.the lymphokine release and antibody production were assessed in the peripheral blood of 52 and 48 cases of amoebic liver abscess respectively, by employing detergent dissected membrane proteins (ddmp) of axenic entamoeba histolytica (nih:200). lymphokine release by t lymphocytes in response to both ddmp and whole amoebic lysate (wal) was performed by leukocyte migration inhibition test. a highly increased release of lmif and 100 per cent positivity was observed with ddmp where as the same for wh ...19911841452
entamoeba histolytica: antigenic characterization of axenic strains from brazil.trophozoites from cultures of entamoeba histolytica strains isolated and grown axenically in brazil (icb-csp, icb-462 and icb-32) were used for immune sera production and for characterization of their antigens by using electrophoretic and glycoproteic profiles, in parallel with a standard strain isolated and kept under axenic conditions in usa (hk-9). hyperimmune sera, presenting high antibody titers with homologous and heterologous antigens, were obtained. the four strains in study revealed sim ...19911843399
dot-enzyme-linked immunosorbent assay (dot-elisa) of anti-entamoeba histolytica antibodies in human serum and colostrum.seroepidemiologic and clinical studies of amoebiasis require improved methods for the detection and titration of anti-entamoeba histolytica (eh) trophozoite antibodies. we have developed a dot-enzyme-linked immunosorbent assay (dot-elisa) to titrate anti-eh antibodies in human serum and colostrum. the anti-eh serum igg antibody titers from healthy individuals and from patients with amoebic liver abscess obtained, with our dot-elisa were similar to those obtained with a standard elisa, but the ba ...19911844108
health impact evaluation of wastewater use in mexico.wastewater from mexico city is used to irrigate over 85 000 hectares, mainly of fodder and cereal crops in the mezquital valley. a cross-sectional study method is being used to test the impact of exposure to raw wastewater and wastewater from storage reservoirs on diarrhoeal disease and parasitic infections in farmworkers and their families. the study population in the rainy season survey included 1 900 households: 680 households where the farmworker is exposed to untreated wastewater (exposed g ...19911844273
[blastocystis hominis in canavese: a retrospective study of samples received for fecal parasitological examination at the ivrea- castellamonte hospital over 42 months].in the last ten years the interest in the controversial blastocystis hominis microorganism of the intestine has greatly increased. the authors conducted a retrospective study of feces for parasitology investigations at the ivrea-castellamonte hospital. these investigations lasted 42 months (1/1/1988-31/6/1991) and the authors focused their attention on samples with 5 or more blastocystis hominis at the microscopically examination with a 40x phase objective. during the study 2,138 samples of fece ...19911844921
antibodies against entamoeba histolytica in individuals with intestinal amoebiasis presenting cysts and/or trophozoites in the feces.serum samples were obtained from 154 individuals infected with entamoeba histolytica (78 symptomatic and 76 asymptomatic). twelve had trophozoites in the feces whereas 142 had only cysts. the sera were used to test the existence of antibodies anti-entamoeba histolytica employing the indirect hemagglutination (iha), indirect immunofluorescence (ifat), complement fixation reaction (cfr) and counterimmunoelectrophoresis (ciep). for those individuals with trophozoites in their feces, 75.0 were posit ...19911844965
crohn's colitis complicated by superimposed invasive amebic colitis.the clinical characteristics and endoscopic appearance of inflammatory bowel disease (ibd) may be very similar to those of amebic colitis. physicians, especially in areas in which amebiasis is endemic, are familiar with this difficulty. moreover, in individual cases, it may even be impossible to distinguish between the two conditions, since stool specimens, bowel biopsies, and serological studies may be negative for entamoeba histolytica, even in the presence of invasive amebic colitis. invasive ...19911858742
variations in cytotoxicity and isoenzyme patterns of uncloned and cloned cultures of axenic entamoeba histolytica.five clones of axenic entamoeba 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. the clone hmi-c121 was more cytotoxic to the cultured baby hamster kidney (bhk) cells while all other clones were significantly (p less than 0.001) less cytotoxic as compared to the cloned hmi-c121 and uncloned e. histolytica (hmi). the uncloned indian axenic e. histolytica (kcg:0986:11) as well as ...19911863471
[preparation of oxime, hydrazone and dichloroacetamide derivatives. researches of antiparasitic activity].several oximes, hydrazones and dichloroacétamides were synthesized. the antiparasitic properties of these compounds were evaluated in vitro against two protozoaires entamoeba histolytica and trichomonas vaginalis.19911867460
amoebic liver abscess. review of 220 cases.two hundred and twenty cases of amoebic liver abscess were seen between 1981-1986. the majority were young or middle aged males belonging to the lower socio-economic group and 85% gave a history of drinking toddy (fermented palm juice). the highest incidence of the disease occurred during the peak toddy season (april to july). toddy drinkers become susceptible perhaps because of the large dose of entamoeba histolytica and bacteria ingested with the drink, associated malnutrition, poor hygiene, h ...19911869393
study of entamoeba histolytica isolates from calcutta with special reference to their zymodeme, animal pathogenicity and erythrophagocytosis.entamoeba histolytica isolates, obtained mainly from asymptomatic human cyst passers, were tested for their in vitro erythrophagocytic activity and lesion-forming ability in hamster liver. simultaneous zymodeme typing of the isolates showed that, along with the pathogenic zymodemes, a number of isolates having nonpathogenic zymodemes also produced liver lesions in hamsters and engulfed higher numbers of rbcs. the observed positive correlation between the rate of erythrophagocytosis of an e. hist ...19911869796
a serum-free, partly defined medium, pdm-805, for axenic cultivation of entamoeba histolytica schaudinn, 1903 and other entamoeba.we describe the first serum-free, partly defined medium (pdm-805) for cultivating the human enteric pathogen, entamoeba histolytica, and the reptilian amebae e. barreti, e. invadens, and e. terrapinae. pdm-805 was developed by the stepwise replacement of yeast extract, bovine serum, and a casein peptone digest in tyi-s-33, a medium widely used for the axenic cultivation of these parasites. the defined components include amino acids, carbohydrates, b vitamins, ascorbic acid, tocopherol, thioctic ...19911880759
pore-forming peptide of pathogenic entamoeba histolytica.a polypeptide that causes pore formation in target-cell membranes is implicated in the potent cytolytic activity of pathogenic entamoeba histolytica. pore-forming material was purified to apparent homogeneity by a multistep procedure, and its analysis by nadodso4/page revealed one peptide of 4-5 kda under nonreducing or under reducing conditions. pore-forming activity was measured by depolarization of liposome membrane potential and was found to be optimally expressed at low ph. active material ...19911881907
characterization of 20 entamoeba histolytica strains isolated from patients with hiv infection.twenty entamoeba histolytica strains from patients with hiv-1 infection were isolated and compared with e. histolytica strains from patients without hiv infection. the isoenzyme pattern of the hexokinase as well as the hybridization with known dna-probes were used as markers for pathogenicity. according to these markers, all 20 strains could be regarded as being nonpathogenic. direct measurements of the virulence were carried out: destruction of monolayer tissue culture cells, capacity of phagoc ...19911889871
isolation of a strain-specific entamoeba histolytica cdna clone.entamoeba histolytica is an intestinal parasite causing significant morbidity and mortality worldwide. more tools are needed to understand the epidemiology and molecular pathogenesis of amebiasis. a cdna library was constructed by using poly(a)+ rna isolated from an axenic strain of e. histolytica, hm1:imss, which expresses a pathogenic isoenzyme pattern (zymodeme). differential screening of the library yielded a strain-specific 3' polyadenylated cdna clone, c2, possessing nine 26-nucleotide tan ...19911890170
molecular probe for identification of trichomonas vaginalis dna.trichomoniasis is one of the most widespread sexually transmitted diseases in the world. diagnosis can be achieved by several methods, such as direct microscopic observation of vaginal discharge, cell culture, and immunological techniques. a 2.3-kb trichomonas vaginalis dna fragment present in strains from diverse geographic areas was cloned and used as a probe to detect t. vaginalis dna in vaginal discharge by a dot blot hybridization technique. this probe was specific for t. vaginalis dna. it ...19911890171
entamoeba histolytica: a simplified method to quantify its cytotoxicity.a simplified and reliable method to quantify entamoeba histolytica cytotoxicity was standardized. mice spleen leucocytes were utilized as target cells. interaction time was reduced to 1 h by pelleting interacting cells. to assess target-cell killing by amoebae, a nigrosine exclusion test was employed. fixation with glutaraldehyde stabilized the percentage of stained target cells. similar results were obtained when cytotoxicity of the e. histolytica hm1 strain was tested by the traditional and pr ...19911894436
distinguishing pathogenic isolates of entamoeba histolytica by polymerase chain reaction. 19911894950
serodiagnosis of invasive amebiasis using a recombinant entamoeba histolytica protein.one hundred eight serum samples from 106 patients were examined by western blot analysis for the presence of antibodies to a recombinant fusion protein containing the sequence of the newly described serine-rich entamoeba histolytica protein (srehp). among patients with invasive amebiasis from durban, republic of south africa; san diego, calif; mexico city, mexico; and st louis, mo, 53 (82%) of 65 had antibodies to srehp. in contrast, only one patient (2%) of 43 without acute invasive amebiasis h ...19911895478
hospital-acquired diarrhea in adults: a prospective case-controlled study in mexico.to know the incidence, etiology, risk factors, morbidity, and mortality of nosocomial diarrhea in adults.19911906497
a study of serum antibody levels against entamoeba histolytica in patients with different amoebic zymodemes.the present study has looked into relative agreement between clinical diagnosis, indirect fluorescent antibody test and iso-enzyme grouping in 35 patients with e histolytica infection. thirty caucasians, who had never travelled to tropical countries were chosen as negative control subjects. there was no remarkable difference in the mean amoebic antibody levels observed with the control subjects and patients harbouring amoebic zymodeme i or iii or iv. whereas, comparative analysis revealed a sign ...19911911488
entamoeba histolytica: microtubule movement during mitosis.the movement of microtubules (mts) during nuclear division of entamoeba histolytica was ultrastructurally studied. regarding this mt movement, five stages of mitosis could be defined: prophase, metaphase, anaphase a, anaphase b, and telophase. in early stages of mitosis, chromatinic material appeared condensed, and mts were detected in the center of the nucleus. later, mts seemed to grow from an electron-dense body located in the center of the nucleus. this body might be the microtubule organizi ...19911915743
amebic pericarditis following ruptured right liver lobe abscess.we present an unusual case of suppurative pericarditis following rupture of a solitary right lobe amebic liver abscess. the condition was treated successfully by drainage of the liver abscess alone.19911916959
incidence of intestinal parasitic disease in an acquired immunodeficiency syndrome day-care center.in june, 1986, the bronx municipal hospital center opened an acquired immunodeficiency syndrome day-care center to provide a quality educational experience for children infected with the human immunodeficiency virus. a major concern was the possibility of increasing secondary infections among these immunocompromised children by placing them in a group environment. one particular worry was intestinal parasitic disease, a serious public health problem in day-care centers throughout the united stat ...19911923677
nucleotide sequence of a small subunit ribosomal rna (16s-like rrna) gene from entamoeba histolytica: differentiation of pathogenic from nonpathogenic isolates. 19911923831
[synthesis and antiparasitic activity of various n-acetylacetates of nitrogen heterocycles].the synthesis and the study of the antiparasitic activity of various heterocyclic n-ethylacetates derived from substituted derivatives of piperazine, benzimidazole and benzotriazole do not show antiparasitic property. a slight activity on entamoeba histolytica and trichomonas vaginalis is noted with the nitro derivatives of benzimidazole and benzotriazole.19911929120
isoenzymes in entamoeba as detected by isoelectrofocusing.two major zymodemes from different entamoeba histolytica strains were detected, despite different growth conditions, using isoelectrofocusing in ultrathin gels. one was associated with strains cultured from symptomatic patients, while the other was associated with microorganisms obtained from clinically symptomatic persons.19911930579
the d-galactose-inhibitable lectin of entamoeba histolytica. 19911933948
dot immunobinding assay versus sandwich elisa in diagnosis of invasive amoebiasis.sera from 34 patients of amoebic liver abscess (ala) and 11 patients with amoebic dysentery (ad) were examined for the presence of specific entamoeba histolytica (eh) antibodies and amoebic antigen by enzyme linked immunosorbent assay (elisa) and dot immunobinding assay (dib). both techniques were found to be equally sensitive for detecting antiamoebic antibodies (89.5 and 91.9% respectively) and highly specific (100%) in patients of ala. elisa was found to be more sensitive (94.4%) in detecting ...19911937593
a new in vitro model of entamoeba histolytica adhesion, using the human colon carcinoma cell line caco-2: scanning electron microscopic study.the human colon carcinoma cell line caco-2, which is widely used to study the adhesion and cytotoxicity of enterobacteria, was used to investigate the adhesion of the trophozoites of entamoeba histolytica. we observed a high percentage of adhesion of amoebae to caco-2 cells. scanning electron microscopy showed that amoebial membrane structures were involved in adhesion and the cytolytic action. these differentiated cells should prove to be a useful model system for investigation of the pathogeni ...19911937772
role of the galactose lectin of entamoeba histolytica in adherence-dependent killing of mammalian cells.entamoeba histolytica extracellular killing of host cells is contact dependent. adherence to human colonic epithelial cells and mucins is mediated by a galactose-specific lectin. the effect on cytotoxicity of a panel of monoclonal antibodies (mab) directed against the galactose lectin was tested. as expected, those mab which inhibited adherence also decreased cytotoxicity. however, one antilectin mab blocked cytotoxicity after adherence had occurred, indicating that the lectin has a role in cell ...19911937828
differences in genomic dna sequences between pathogenic and nonpathogenic isolates of entamoeba histolytica identified by polymerase chain reaction.a lambda gt11 cdna library was constructed from the poly(a)+ rna of trophozoites of entamoeba histolytica hm-1:imss strain. the library was immunologically screened with monoclonal antibody 4g6, which is specific for the 30,000-mr antigen of pathogenic isolates. a 0.7-kb clone was isolated, and its nucleotide sequence was determined. to examine whether this gene was specific for pathogenic isolates, a polymerase chain reaction was performed by using four sets of primers and the genomic dna of pa ...19911939576
protein a-antibody mediated hemagglutination assay for serodiagnosis of amebic liver abscess.a successful modification of the indirect hemagglutination test to demonstrate antibodies for serodiagnosis of amebic liver abscess has been described in the present study. in the modified test, the protein a-ima, staphylococcus aureus (cowan's strain i) bearing protein a (sapa) cells were used to enhance hemagglutination of sensitized red cells. use of sapa cells markedly enhanced sensitivity of the test and greatly increased the titers obtained with most of the sera. at a diagnostic antibody t ...19911948287
pathogenicity and antigenic components of excysted giardia lamblia isolated from patients in riyadh, saudi arabia.giardia lamblia cysts were isolated from patients in riyadh, saudi arabia. cysts and trophozoites (from axenically excysted cysts) were given orally by gavage to mice to establish the pathogenicity of the riyadh isolate. there was no effect of varying the dose of administered parasite on parasite excretion or morbidity. a typical pathologic pattern of giardiasis was demonstrated by histologic methods and electron microscopy. antigenic components of the riyadh isolate were compared with the portl ...19911951852
intestinal parasitic infestation in pediatric gastroenterology outpatient clinic dr. pirngadi hospital medan.a retrospective study had been done at the outpatient clinic sub division of pediatric gastroenterology, dr. pirngcdi hospital medan, comprising patients from 1 january 1985-31 december 1987. there were 874 patients. three hundred seventy eight (43.25%) patients consisting of 210 (55.56%) males and 168 (44.44%) females had intestinal parasitic infestations. the youngest patient was 5 months and the oldest was 14 years and 3 months. ascaris lumbricoides was found in 215 patients (24.60%) while tr ...19911956691
factors associated with the detection of entamoeba histolytica in homosexual men.in a study of bowel parasites in 128 australian homosexual men attending a sexually transmitted diseases (std) clinic, entamoeba histolytica was detected in 37%, giardia intestinalis in 3% and at least one protozoan in 81% of the group. there was no evidence of pathogenicity of e. histolytica, nor was there any association between the detection of e. histolytica and sexual practices, gastrointestinal symptoms, proctitis, human immunodeficiency virus antibody result or t-cell subset values. howev ...19911958719
[experimental studies on the concurrent infections with entamoeba histolytica and schistosoma japonicum].the mongolian gerbil (merious unguiculatus) was used as an experimental animal model for studying the concurrent infections and pathogenicities with entamoeba histolytica (e. h.) and schistosoma japonicum (s. j.) by the cutaneous infection with 20 fresh cercariae of s. j. and the intracaecal inoculation of 5 x 10(5)/0.5 ml amebic suspension. light and electron microscopy were used to observe the pathological changes of the caecal wall in the concurrent infections. the results showed that s. j. i ...19911959165
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 ...19911653955
[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 ...19911655921
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 ...19911658540
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- ...19911661350
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 ...19911670482
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 ...19911671621
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 ...19911672533
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 ...19911677159
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.19911682453
application of atp measurement to evaluation of the growth of parasitic protozoa in vitro with a special reference to pneumocystis carinii.1. there was a significant correlation between the increase in the number of entamoeba histolytica, trichomonas vaginalis, giardia lamblia and leishmania donovani in culture, and their atp contents determined by luciferase reaction. 2. the similar correlation was also demonstrated between the decreased number of e. histolytica in the presence of an anti-amebic quassinoid and the nucleotide content in vitro. 3. in the case of pneumocystis carinii, the numbers of the organism remained relatively c ...19911685366
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 ...19911685555
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 ...19911686143
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 ...19911686625
giardiasis and amoebiasis infections in three saudi closed communities.two hundred and eighteen residents (131 healthy and 87 mentally or physically retarded) of a children's nursery, a foster house and a rehabilitation centre for the handicapped in abha, southwestern saudi arabia, were examined for intestinal parasitism. about 30% of the population of the three communities were found to harbour asymptomatic infections with either giardia lamblia and/or entamoeba spp. giardia cysts were identified in 19.3% of those examined. entamoeba histolytica was found in 18.4% ...19911995937
biochemical and ultrastructural studies induced by phanquone on entamoeba histolytica nih-200.the action of phanquone on the incorporation of (14c)1-dl-valine and (14c)-8-adenine in tca insoluble fractions of entamoeba histolytica was examined as indices of rna and protein synthesis respectively. the former was found to show greater sensitivity to the drug in terms of the effect manifested in the dose response curves for these parameters. electron microscopic investigations with increasing concentrations of the drug demonstrated progressive vacuolization with concomitant dissolution of r ...19911918871
protection of gerbils from amebic liver abscess by immunization with the galactose-specific adherence lectin of entamoeba histolytica.no protective antigens from entamoeba histolytica have been previously defined. we tested the ability of the galactose-specific adherence lectin of e. histolytica to elicit a protective immune response in conjunction with freund's incomplete and complete adjuvants. the gerbil (meriones unguiculatus) model of an experimental amebic liver abscess was used. gerbils were immunized intraperitoneally or subcutaneously with 10 micrograms of the affinity-purified lectin in complete freund's adjuvant and ...19911987067
intracranial amebic abscesses: ct and mr findings.the ct and magnetic resonance findings in a case of intracranial amebic abscesses are described. due to increased travel to endemic areas, amebic abscess should also be included in the differential diagnosis for patients who live in the temperate parts of the world.19911987193
entamoeba histolytica: recognition of alpha- and beta-galactose by the 260-kda adherence lectin. 19911993459
entamoeba histolytica infection and aids. 19911996598
primary structure of the 170-kda surface lectin of pathogenic entamoeba histolytica.the adherence of entamoeba histolytica to colonic mucins and to host cells appears to be predominantly mediated by a 170-kda surface lectin of the amoebae. by using an antiserum to the purified lectin, the corresponding cdna was isolated from an expression library of the pathogenic e. histolytica isolate hm-1:imss. northern blot analysis indicated a transcript of approximately 4 kilobases, and southern blot analyses suggested that multiple genes may encode the lectin or closely related proteins ...19912000392
mucin and nonmucin secretagogue activity of entamoeba histolytica and cholera toxin in rat colon.depletion of colonic mucus occurs before invasion of the colonic mucosa by entamoeba histolytica trophozoites. it is hypothesized that e. histolytica releases a mucus secretagogue; this was studied in a rat colonic loop model. in colonic loops exposed to live amebae, mucus secretion was quantitated by release of acid-precipitable [3h]glucosamine-labeled luminal glycoprotein and by specific immunoassay. mucus secretion increased in dose-dependent fashion in response to greater than or equal to 1 ...19912001836
cloning and characterization of an unusual elongation factor-1 alpha cdna from entamoeba histolytica.the coding sequence deduced from two overlapping cdna inserts obtained from a pathogenic strain of entamoeba histolytica revealed a striking homology (greater than 85%) with elongation factor ef-1 alpha from saccharomyces cerevisiae and artemia salina. the deduced amino acid sequence predicted a size of 49 kda, and antibodies raised against the s. cerevisiae ef-1 alpha cross-reacted with an amoebic protein of similar size (45-47 kda). sequence analysis of the cdna revealed that the 5' untranslat ...19912011152
sexually transmitted parasitic diseases.sexual activity is the primary method of transmission for several important parasitic diseases and has resulted in a significant prevalence of enteric parasitic infection among male homosexuals. the majority of parasitic sexually transmitted diseases involve protozoan pathogens; however, nematode and arthropod illnesses are also included in this group. trichomoniasis, caused by trichomonas vaginalis, is the most common parasitic std. infection with this organism typically results in the signs an ...19912011632
increased frequency of hla-dr3 and complotype sc01 in mexican mestizo patients with amoebic abscess of the liver.our preliminary study (31 patients) of hla frequencies and amoebic abscess of the liver (aal) in mexican mestizos was extended to include 110 patients with this condition. the previously found increase in hla-b16 was not confirmed, but the frequency of hla-dr3 was again found significantly increased in patients with aal when compared to the normal, ethnically matched control population, both in its isolated (35.5% vs 12.7%) and in the hla-a2, dr3 haplotypic version (20.9% vs 4.5%). moreover, sev ...19912014135
immunoprecipitation studies with biotinylated entamoeba histolytica antigens.the biotinylation of protein antigens for use in immunoprecipitation studies with parasite antigens is described. this technique was standardized to produce maximal labelling without compromising either the viability of the parasite or the antigenicity of labelled proteins. live axenic entamoeba histolytica trophozoites were optimally labelled by incubation of 10(7) parasites in 1 ml phosphate-buffered saline for 20 min at 37 degrees c with a final concentration of 10 mm n-hydroxy succinimido-bi ...19912014137
sequence of a cysteine-rich galactose-specific lectin of entamoeba histolytica.entamoeba histolytica trophozoites adhere to human colonic mucins and epithelial cells by a cell surface galactose-specific lectin. this lectin, which is composed of two subunits linked by disulfide bonds, has been shown to be a protective antigen in an animal model of amebiasis. we have determined the sequence of the mature form of the 170-kda heavy subunit from cdna clones and pcr-amplified fragments. the heavy subunit sequence consisted of a putative extracellular domain containing 1209 amino ...19912014248
entamoeba histolytica: generation and characterization of hybrid clones.transference of dna to entamoeba histolytica was carried out by polyethylene glycol fusion of two amebic clones with different phenotypes. clone c9, strain hm1:imss, was the donor. it is emetine-resistant, highly phagocytic and virulent, and grows in soft agar. clone l6, strain hm1:imss, the recipient, is emetine-sensitive, phagocytic, and virulence-deficient, and it does not grow in soft agar. clones l6 and c9 have shown high stability in their virulence phenotypes since their isolation more th ...19912015865
intestinal parasites in cambodians: comparison of diagnostic methods used in screening refugees with implications for treatment of populations with high rates of infestation.we performed a retrospective review of screening parasitology examinations on a cambodian refugee population served by an urban neighborhood health center. five-hundred twenty of 1084 patients were examined for ova and parasites either by purged stool, which was examined immediately, or preserved stool, examined at a teaching hospital and proprietary laboratories. overall, 335 (64 percent) of the tested patients had at least one parasite. the prevalence of infection varied by test technique (pur ...19912028827
fulminant amebic colitis.amebiasis is the acute and chronic disease produced by entamoeba histolytica, an entity which occurs in endemic fashion in many of the tropical and subtropical areas of the world, capable of affecting diverse organs of the body, especially the colon. amebiasis has different clinical forms of presentation, varying from the asymptomatic carrier state to severe, although not frequent, fulminant or necrotizing colitis, characteristically associated with high morbidity and mortality. we hereby report ...19912031357
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