| 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 |
| [blastocystosis and other intestinal protozoan infections in human riverside communities of the valdivia river basin, chile]. | between march and october 1987, the prevalence of infection by blastocystis hominis and other intestinal protozoan, their relationship with the age and sex of the hosts, and the percentage of infected persons in family groups were determined in riverside communities of valdivia river basin, chile. one or more intestinal protozoan species were determined in 72.5% of the examined persons. the prevalence was greater for b. hominis (61.8%). the prevalences of b. hominis, endolimax nana and entamoeba ... | 1992 | 1342125 |
| 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 |
| colonization of the uterus by the oral protozoan entamoeba gingivalis. | pap smears occasionally reveal protozoa of the genus entamoeba in the uterus of intrauterine device (iud) users, but definitive identification of the species involved has not been possible. using riboprinting, a technique that compares ribosomal rna gene sequences, we present evidence that the organism is entamoeba gingivalis, an inhabitant of the mouth. colonization most likely occurs via orogenital contact and requires the presence of an iud and a concomitant bacterial infection. | 1992 | 1539749 |
| 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 |
| phenotypic heterogeneity in the expression of a 30 kda cysteine proteinase in axenic cultures of entamoeba histolytica. | a polyclonal antibody raised against a purified approximately 30 kda cysteine proteinase derived from extracts of axenically grown trophozoites of e. histolytica strain hm-1:imss was used to stain 72 h cultures of the same amebas by indirect immunofluorescence. fluorescence was limited to the outer membrane of the parasite and was either uniformly distributed or more condensed on a segment, at times on a single point of the membrane. in relation to the intensity of fluorescence staining, three d ... | 1992 | 1340332 |
| 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 |
| 'entamoeba histolytica' is a complex of two species. | | 1992 | 1412672 |
| 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 |
| 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 |
| 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 |
| the prevalence of entamoeba gingivalis and trichomonas tenax in periodontal disease. | two hundred patients (100 males and 100 females) having either marginal periodontitis or gingivitis were examined for detection of e. gingivalis and t. tenax. e. gingivalis was more prevalent among patients with periodontitis particularly females, while t. tenax was not discovered entirely in both patients and control groups. | 1992 | 1578154 |
| entamoeba motility: dynamics of cytoplasmic streaming, locomotion and translocation of surface-bound particles, and organization of the actin cytoskeleton in entamoeba invadens. | the dynamics of cytoplasmic streaming, retrograde translocation of externally bound particles and locomotion by entamoeba invadens were compared. locomoting amoebae were monopodial, exhibited fountain flow cytoplasmic streaming and translocated externally bound erythrocytes to the rear of cells. the rates of rearward flow of peripheral cytoplasmic vacuoles and of the externally bound particles were equal to the rate of cell forward locomotion. rhodamine-phalloidin staining revealed a distinct co ... | 1992 | 1578401 |
| 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 |
| an overview of molecular parasitology in china. | molecular cloning technology has been gradually used in the studies of parasitic diseases in china since 1986. the information briefly reviewed here deals mainly with: (1) the molecular cloning of immunogen genes related to schistosome and plasmodium; (2) a diagnostic dna probe for malaria and toxoplasmosis; and (3) dna probes for inter- and intra-specific differentiation of leishmania, schistosome, entamoeba, etc. | 1992 | 1597082 |
| 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 |
| [in vitro decrease of the cytolytic effect of e. histolytica by inhibition of its phosphofructokinase]. | the c14 radioactive label of ppi analogues was incorporated to e. histolytica after 24 hours of incubation at 37 degrees c; more than 90% of trophozoites remained viable. the ppi dependent phosphofructokinase was isolated in order to determine its kinetic parameters. with ppi, the km was 18.06 +/- 0.91 micromol/ml-1. using three different ppi analogues (tetrasodium salts) of (i) 1,1 hydroxy-methyl diphosphonate; (ii) 1,1 hydroxy ethylene diphosphonate; (iii) 1,1 hydroxy-nonano diphosphonate, kii ... | 1992 | 1345117 |
| [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 |
| 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 |
| 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 |
| [occurrence of the protozoa, entamoeba gingivalis and trichomonas tenax in the mouths of children and adolescents with hyperplastic gingivitis caused by phenytoin]. | the oral protozoa entamoeba gingivalis and trichomonas tenax do not occur in small children and are rarely found in older ones. in adolescents their occurrence rate keeps increasing with age. they parasitize in an oral cavity changed by inflammation, yet also in a healthy mouth. their highest occurrence rate has been recorded in adults with periodontosis and atrophy of the periodontium, a somewhat lower one in adults with gingivitis. the authors addressed the question whether the presumed low oc ... | 1992 | 1525687 |
| 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 |
| entamoeba coli as cause of diarrhoea? | | 1991 | 1672011 |
| 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 |
| entamoeba coli as possible cause of diarrhoea. | | 1991 | 1676806 |
| 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 |
| immediate autoproteolysis and new proteinases in entamoeba invadens and entamoeba moshkovskii trophozoites. | we have examined the sodium dodecyl sulfate (sds)-induced autoproteolysis of e. invadens (pz and ip101) and e. moshkovskii (fic and laredo) trophozoite lysates. heat-treated lysates containing parahydroxy-mercuribenzoate (phmb) of all four strains had undegraded protein patterns. unheated phmb-lacking lysates of pz had two (99 and 90 kda) and ip101 lysates had three (45, 99, 90 kda) major proteins, whereas fic and laredo lysates had only one (90 kda). heat-treatment changed the remaining protein ... | 1992 | 1340331 |
| 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 |
| the effect of axenic versus xenic culture conditions on the total and secreted proteolytic activity of entamoeba histolytica strains. | proteolytic activity was measured in lysates of four axenic and five xenic cultures of different strains of pathogenic e. histolytica, and in five non-pathogenic strains ("e. dispar") growing in xenic culture. there was no significant difference in total proteolytic activity, using either gelatin or albumin as substrate, between the two sets of xenic cultures; the axenic pathogens however had significantly higher levels of activity than the xenic pathogens, the levels appearing to correlate with ... | 1992 | 1340330 |
| 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 |
| roles of target cell membrane carbohydrate and lipid in entamoeba histolytica interaction with mammalian cells. | latex beads and liposomes carrying glycoproteins with carbohydrate sequences recognized by an entamoeba histolytica galactose-specific binding protein were assessed for their ability to adhere to trophozoites and to stimulate amoeba actin polymerization. glycoprotein-conjugated beads bound significantly to amoebae but did not stimulate actin polymerization. glycoprotein-bearing liposomes bound to amoebae and did enhance actin polymerization, as do recognized glycosphingolipid-bearing liposomes ( ... | 1990 | 1694827 |
| cloning and expression of a membrane antigen of entamoeba histolytica possessing multiple tandem repeats. | entamoeba histolytica causes amebic dysentery and amebic liver abscess, major causes of morbidity and mortality worldwide. we have used differential hybridization screening to isolate an e. histolytica-specific cdna clone. the cdna was found to encode a serine-rich e. histolytica protein (srehp) containing multiple tandem repeats. the structural motif of srehp resembles some of the repetitive antigens of malarial species, especially the circumsporozoite proteins. a recombinant trpe fusion protei ... | 1990 | 1695007 |
| characterization of an immuno-dominant variable surface antigen from pathogenic and nonpathogenic entamoeba histolytica. | a 125-kd surface antigen of entamoeba histolytica is recognized by 73% of immune sera from patients with amoebic liver abscesses. using pooled human immune sera a cdna clone (lambda cm17) encoding this antigen (m17) has been isolated from a lambda gt11 expression library of the virulent stain e. histolytica hm1:imss. monospecific antibodies, purified by binding to phage lysate of lambda cm17, and mab fa7 reacted exclusively with the 125-kd antigen by western blot analysis. surface binding and ca ... | 1990 | 1696956 |
| characterization of a monoclonal antibody that selectively recognizes a subset of entamoeba histolytica isolates. | monoclonal antibody 2d7.10 recognized an antigen present in seven of nine isolates of axenically cultured entamoeba histolytica and absent in all other entamoeba isolates studied. the antigen was absent in two isolates: 200:nih and rahman. all nine isolates belonged to pathogenic zymodeme ii. western blot (immunoblot) analysis and treatment with periodate and the proteolytic enzyme trypsin suggest that the antigen recognized by 2d7.10 is a carbohydrate moiety. | 1990 | 1698182 |
| detection of igg, iga, igm and ige antibodies in invasive amoebiasis in endemic areas. | entamoeba histolytica-specific serum igg, iga, igm and ige antibodies were assayed in cases of amoebiasis in an endemic area. patient groups consisted of amoebic liver abscess (n = 18), preabscess hepatic amoebiasis (n = 22) and amoebic colitis (n = 30). control subjects comprised 26 asymptomatic cyst passers, 13 giardiasis cases, 20 typhoid patients and 24 non-amoebic individuals. serum igg was assayed by elisa, using a monoclonal anti igg beta-galactosidase (igg beta-gal) conjugate, a polyclon ... | 1990 | 1699266 |
| variation of proteins and proteinases in entamoeba histolytica lysates containing a protease inhibitor. | sodium dodecyl sulfate (sds)-lysates of e. histolytica trophozoites were analyzed by electrophoresis in simple and gelatin-containing ("substrate") sds-polyacrylamide gels. in simple gels, boiled lysates with para hydroxymercuribenzoate (phmb) had a complex pattern of apparently undegraded proteins; boiled lysates without phmb showed a major 30 kda and four minor (43, 46, 63 and 117 kda) proteins, whereas unheated lysates displayed only the 117 kda protein. using substrate gels no gelatinases we ... | 1992 | 1340329 |
| 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 ... | 1991 | 1705935 |
| an antibiotic-free medium for the xenic cultivation of entamoeba gingivalis. | diamond's tyi-s-33 (trypticase-yeast extract-iron-serum) medium was used as the basis for a new antibiotic-free medium for xenic growth of entamoeba gingivalis. nutritional requirements of the oral protozoan were determined in an effort to optimize growth. tyi-s-33 medium did not support e. gingivalis growth prior to modification. the changes included: (a) deletion of l-cysteine.hcl and thioctic acid, (b) substitution of glucose for dextran i (mol. wt 185,000) or rice starch, (c) reduction of co ... | 1991 | 1717390 |
| further diagnostic use of an invasive-specific monoclonal antibody against entamoeba histolytica. | genotypic differences between invasive and non-invasive e. histolytica could explain the 1:10 ratio of symptomatic/asymptomatic infection worldwide. currently, zymodeme analysis is used to differentiate invasive from non-invasive e. histolytica strains but the technique is cumbersome and expensive. in accordance with the who research priorities for amebiasis we report here the further use of an invasive-specific monoclonal antibody against e. histolytica in immunofluorescence, to identify isolat ... | 1992 | 1340315 |
| serodiagnosis of invasive amebiasis using a recombinant entamoeba histolytica antigen-based elisa. | amebic serology remains a critical component in the diagnosis of invasive amebiasis. a recombinant serine rich-entamoeba histolytica-protein/maltose binding protein (srehp/mbp) fusion protein was evaluated as the target antigen in an elisa test to detect acute invasive amebiasis. retrospective analysis of 65 serum samples from patients with amebic liver abscess and 40 asymptomatic control patients showed the srehp/mbp elisa test had a sensitivity of 74% and specificity of only 55% for the diagno ... | 1992 | 1340316 |
| low risk of invasive amebiasis in cyst carriers. a longitudinal molecular seroepidemiological study. | a seroepidemiological study of a household cohort, using both clinical observational and molecular criteria was conducted in a periurban area endemic for e. histolytica infection. this longitudinal study was undertaken to determine the risk of asymptomatic cyst carriers to develop invasive illness. zymodeme patterns of strains isolated from these patients were correlated both with the clinical presentation of disease and with the serological response against the m-17 ameba antigen and further co ... | 1992 | 1340317 |
| chromosome walk in entamoeba histolytica: the gene encoding for ribosomal protein l21 neighbors one of the actin genes. | actin is one of the most abundant proteins in the motile intestinal protozoan parasite e. histolytica. a number of actin gene copies have been detected. the cdna and genomic sequences of two of the actin genes have been independently reported (1,2). almost complete homology was detected between the coding regions of the two genes; however, significant differences were observed in the sequences of their 5' untranslated regions. using the coding region of actin as the focal point, we performed a c ... | 1992 | 1340321 |
| axenic massive cultivation of entamoeba histolytica trophozoites in spinner flasks and in a microfermentor. | a medium, pehps, whose main components are extracts of ox liver, and ox and swine pancreas (ehp) was used to develop two alternative methods for axenic cultivation of trophozoites in suspension: with magnetic stirrer and with a 14 l capacity microfermentor, giving the first technic yields of 2.36 x 10(5) to 3.08 x 10(5) and the second in a 14 l capacity microfermentor, which produced 1.65 x 10(5) amebas/ml in one batch and 2.94 to 3.65 x 10(5) of such parasites/ml at semicontinuous flux. | 1992 | 1340322 |
| effects of albendazole on entamoeba histolytica and giardia lamblia trophozoites. | albendazole, a benzimidazole carbamate commonly used for the treatment and control of intestinal helminthic infections, is also useful for the treatment of giardiasis. therefore, it is of interest to determine whether the drug has activity against other intestinal protozoa, such as e. histolytica. the present results demonstrate that albendazole inhibits the growth of e. histolytica trophozoites in axenic cultures and induces fine structural changes such as polyribosome aggregation and loss of c ... | 1992 | 1340323 |
| further studies on the in vitro activity of gossypol as antiamebic agent. | gossypol has an in vitro antiamebic effect, which is 11,39, and 980 times more potent than emetime, metronidazole and diiodohydroxyquinolein, respectively, on five entamoeba histolytica axenic strains. the trophozoite nadp-dependent malic enzyme and alcohol dehydrogenase are inhibited by (+/-)-gossypol, in a noncompetitive manner with respect to the substrate. from the (-)- and (+)- enantiomers, which integrate the natural gossypol mixture, the first one is three and four times more active in in ... | 1992 | 1340324 |
| improved molecular karyotype of entamoeba histolytica. | different electrophoretic conditions were used to improve the molecular karyotype of entamoeba histolytica clone l6 derived from the heterogeneous strain hm1:imss. eleven to 17 bands ranging between 0.3 and over 3 megabases (mb) were resolved by transverse alternating field electrophoresis (tafe). amebic chromosomes presented similar pattern when they were tafe separated at 72, 90 or 120 h running time, but resolution of the bands was increased at 90 h, and the best electrophoretic pattern was o ... | 1992 | 1340325 |
| stability of the zymodemes of entamoeba histolytica in culture. | | 1992 | 1340326 |
| the fine structure of entamoeba histolytica processed by cryo-fixation and cryo-substitution. | recently, the use of cryo-fixation followed by freeze-substitution has been shown to produce a better ultrastructural preservation of cellular components due to the rapidity of the fixation procedure and the lack of distortion during dehydration. when these techniques are applied to study the fine structure of axenically cultured trophozoites of e. histolytica, an improved preservation of cytoplasmic and nuclear components was found. the surface coat of the parasite appears much thicker and unif ... | 1992 | 1340327 |
| entamoeba histolytica: electrophoretic analysis of isolated caps induced by several ligands. | caps induced by several ligands including sera from patients with amebic liver abscess (ala) were isolated by differential centrifugation. purification was verified by scanning and transmission electron microscopy. electrophoretic profiles obtained by sds-page and western blots were compared when probed with the ligand used to induce capping. it was confirmed that sera from different patients recognize different proteins. indeed, electrophoretic profiles reveal that capped membrane proteins vary ... | 1992 | 1340328 |
| 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 |
| 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 |
| axenic cultivation of entamoeba histolytica in suspension. | | 1992 | 1440780 |
| 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 |
| 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 |
| amebic colitis in inflammatory bowel disease. | | 1992 | 1556420 |
| 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 |
| chitinase activity in encysting entamoeba invadens and its inhibition by allosamidin. | chitinase activity was measured in extracts of entamoeba invadens cells as a function of time of encystation in axenic conditions using 4-mu(ch)3 as substrate. encystment was paralleled by chitinase activity which showed a peak after about 72 h of cultivation where cysts accounted for 63% of cell population. thereafter, activity fell off rapidly, whereas encystment continued, reaching 80% at the end of the experiment (96 h). comparison of activity between cysts and the total cell population in 4 ... | 1992 | 1625707 |
| 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 |
| 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 |
| 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 |
| 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 |
| [cross-reacting antigens of amebas and rat intestinal mucosa]. | the experiments have shown the presence of cross-reacting systems in entamoeba histolytica and in intestinal tissues of random noninbred albino rats. the antigenic affinity between e. histolytica and e. moshkovskii was expressed very weakly. | 1990 | 1705308 |
| specificity of commercially available entamoeba histolytica antigen in enzyme-linked immunosorbent assay (elisa) to sera from dogs with various parasitic infections. | | 1991 | 1718445 |
| 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 ... | 1991 | 1724012 |
| 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 ... | 1991 | 1724953 |
| [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 ... | 1991 | 1725928 |
| [role of leukocytes and amebic proteases in experimental testicular necrosis produced in the rat by entamoeba histolytica]. | we examined the participation of polymorphonuclear leucocytes and amebic proteinases upon tissue damage by means of an experimental model of acute amebic lesions developed in rat's testicle. in leukopenic rats (less than 1,000 leucocytes/ml) intratesticular injection of axenic e. histolytica's trophozoites (hm-1) produced lesions undistinguishable from the normal controls. on the other hand, inhibition of 80% (average) of the proteinase activity by means of previous incubation of the trophozoite ... | 1990 | 1726660 |
| [obtaining monoclonal antibodies against outer membrane glycoproteins of entamoeba histolytica]. | the goal of this paper was the production of monoclonal antibodies capable of detecting relevant antigens from the surface of entamoeba histolytica trophozoites, with the purpose of using them as a diagnostic test. the cellular fusion for obtaining the monoclonal antibodies (mab) was done with spleen cells from balb/c mice, previously immunized with glycoproteins from the membrane, as well as sp2/0 cells. the hybridoma supernatants were tested with elisa, using glycoproteins and lipopeptide phos ... | 1990 | 1726661 |
| [antigens specific to pre-cysts and in vivo chitin synthetase activity in entamoeba invadens]. | in this paper we studied the transformation of a trophozoite into a cyst in entamoeba, using e. invadens as a model. we had the following objectives: a) identification of precyst-specific proteins (p), by a monoclonal antibody against e. invadens and heterologous polyclonal antibodies against cellular (165) fractions of mucar rouxii, which are chitin synthetase activity rich; and b) in vivo determination of the time required for the expression of activity of the chitin synthetase during encystme ... | 1990 | 1726662 |
| [the eosinophil and entamoeba histolytica. ii. testicular amebic lesions produced in eosinophilic rats]. | even though eosinophiles are not characteristic of amebiasis, polymorphonuclear eosinophilic cells are regularly found in the inflammatory lesion which occurs in the early phases of amebic invasion. to acquire better knowledge of the intervention of these cells when confronted with e. histolytica, testicular lesions were produced by means of direct injection of amebas in rats with eosinophilia. eosinophilia (greater than or equal to 4%) was induced in male sprague dawley rats by an intravenous i ... | 1990 | 1726663 |
| use of non-cellular models to study the interaction of e. histolytica with mammalian cells. | we have utilized liposomes constructed with individual mammalian cell membrane glycosphingolipids and latex beads conjugated with glycoproteins as models to investigate the molecular specificity and mechanism of interaction of e. histolytica with target cells. synthetic liposomes constructed with a variety of glycosphingolipids bearing neutral, straight chain glycans with galactose or n-acetylgalactosamine termini stimulated rapid (90 sec), contact dependent polymerization of e. histolytica acti ... | 1990 | 1726664 |
| molecular and cellular characterization of the 29-kilodalton peripheral membrane protein of entamoeba histolytica: differentiation between pathogenic and nonpathogenic isolates. | to further characterize the 29-kda surface antigen of entamoeba histolytica, we analyzed the complete nucleotide sequence and compared the immunoreactivity of this antigen in pathogenic and nonpathogenic strains. five cdna clones (one 1.0-kb full-length clone, designated p13, and four partial-length clones) encoding the antigen were analyzed for allelic variation. comparison of the nucleotide sequences revealed several single-nucleotide substitutions in all five cdnas, two of which resulted in a ... | 1992 | 1730488 |