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intestinal opportunistic parasites among different groups of immunocompromised hosts.the present study was designed to find out the prevalence of different intestinal opportunistic parasites in different groups of immunocompromised hosts; patients suffering from malignancy with or without immuno-suppressive drugs, or with chronic renal failure, or diabetes mellitus, or subjects under cortisone therapy. examination of stool samples collected from 427 immunocompromised hosts revealed the detection of intestinal opportunistic parasites in 98 samples, with a prevalence of 23%. infec ...19958586866
chronic diarrhea among adults in kigali, rwanda: association with bacterial enteropathogens, rectocolonic inflammation, and human immunodeficiency virus infection.one hundred patients with chronic diarrhea were seen in the department of internal medicine at the centre hospitalier de kigali, rwanda; stool and/or rectal swab culture was performed for these patients, and they underwent rectoscopy and serological testing for human immunodeficiency virus type 1 (hiv-1). enteropathogenic bacteria were isolated from 39 (39%) of the patients: shigella species (22 of 100 patients tested), non-typhi salmonella (11/100), aeromonas species (5/60), and campylobacter s ...19958589155
[interleukin-8 gene expression in the human colon epithelial cell line, ht-29, exposed to entamoeba histolytica].the protozoan parasite, entamoeba histolytica, is one of major causative agents of intestinal disease all over the world. in acute experimental infection, the early host response to e. histolytica is characterized by an infiltration of neutrophils. however, the chemotactic signal for this response is not well known. based on the finding that human epithelial cells produce the potent neutrophil chemoattractant and activator, interleukin-8 (il-8), il-8 gene expression was examined thoroughly in hu ...19958591014
axenization of entamoeba histolytica, a korean strain ys-27.in the present communication, ys-27, a korean strain of entamoeba histolytica is described for the isolation and establishment of axenic cultivation. e. histolytica, designated as strain "ys-27", was isolated from the pus of a hepatic abscess obtained from a 72 year old inpatient of august 10, 1969. specimens, were obtained by needle aspiration, inoculated immediately and weekly cultured in a modified diphasic medium at 37 degrees c. strain ys-27 had been maintained for more than 15 years by wee ...19958591018
[parasitic diseases of the liver].the liver seems to be very attractive for many parasites which may either inhabit the organ or pass through during their normal development or may be carried to the liver leading to destruction there. malaria parasites have a short developmental stage in the hepatocytes, but they do not damage the organ. for the leishmanias (leishmania donovani complex) are the kupffer cells are the target cells causing visceral leishmaniasis or kala azar. nematodes of the ascarid group have a special affinity f ...19958600687
diagnosis of amoebic infection of the liver: report of 36 cases.the classical clinical picture of amoebic infection of the liver consists of fever, right upper quadrant pain and hepatomegaly. in recent years, the widespread availability of ultrasound and serology made an early diagnosis possible, which could result in less prominent clinical pictures. thirty six cases of liver amoebiasis diagnosed in antwerp between 1985 and 1992, were reviewed. three patients acquired their infection in belgium. for the other patients, the average delay between arrival in b ...19958669977
characterization of adhesion plates induced by the interaction of entamoeba histolytica trophozoites with fibronectin.entamoeba histolytica trophozoites are pleiomorphic and highly motile cells. although scarce fibrous material can be identified in the cytoplasm as elements of an organized cytoskeleton, clearly defined actin-containing structures are formed at the site of cell-matrix contact upon the interaction of trophozoites with fibronectin (fn) and other cellular matrix substrates. the structures are reminiscent of the adhesion plaques or focal contacts found in higher eukaryotic cells, where actin filamen ...19958674132
the outpatient management of bloody diarrhea in young children. 19958613324
[application of the polymerase chain reaction to the epidemiological study of amoebiasis].the polymerase chain reaction (pcr) has been used in studying the pathogenicity of entamoeba histolytica in a rural community in shandong province. formalin-fixed stool samples were used for extraction of dna. the pcr amplifications were performed using two sets of primer that discriminate between pathogenic and nonpathogenic e. histolytica. all of the 32 cases of cyst carrier diagnosed microscopically were identified as positive. three groups were defined through pcr analysis: 6 cases (18.8%) w ...19958706101
transient expression of luciferase in entamoeba histolytica driven by the ferredoxin gene 5' and 3' regions.we have successfully transfected entamoeba histolytica trophozoites with constructs containing ferredoxin sequences fused to the reporter gene luciferase. we have determined the conditions and parameters necessary to maximise transient luciferase expression in our system. our optimal construct gave values of 268 x 10(3) relative light units per second (rlu s-1) when assayed representing a stimulation of 18,000-fold over the control vector. comparison of differing constructs allowed us to conclud ...19958719240
reduction in virulence of naegleria fowleri following growth with cholesterol.it has been reported that the virulence of axenically cultivated entamoeba histolytica increases following growth with cholesterol. the purpose of this study was to determine whether cholesterol would enhance the virulence of axenically cultivated naegleria fowleri. amoebae were cultivated in axenic medium with (100 micrograms/ml) or without cholesterol for 6 months and tested in mice for changes in virulence. after 6 months of continuous cultivation. n. fowleri grown with cholesterol was less v ...19958774777
parasitic contamination of stored water used for drinking/cooking in hyderabad.a study was undertaken to investigate the parasitic contamination of water in hyderabad city, india. a total of 232 samples of water were collected from different places; social welfare hostels, small restaurants, different households, public places like railway stations, bus depots, street food vendors, hand washings from the food handlers, and vegetable washings from vegetable vendors. of these 232 samples 61 samples indicated the presence of pathogenic parasites which include protozoans (cyst ...19959139396
new concepts regarding the pathogenesis of amebiasis.our understanding of the pathogenesis of amebiasis has progressed significantly since dr. braude's description of the major clinical syndromes of amebic liver abscess. his hypothesis that invasive amebic strains must be resistant to complement-mediated lysis has been confirmed. we have also shown that entamoeba histolytica activates complement by a unique mechanism, i.e., cleavage of c3 by an extracellular cysteine proteinase. cysteine proteinases are important virulence factors encoded by at le ...19958845450
antigen induced eosinophilia protects gerbils (meriones unguiculatus) against experimental amebic abscess of the liver.while the normal human eosinophil is destroyed in vitro by virulent entamoeba histolytica, notwithstanding the presence of antibodies and complement, activated eosinophils promptly destroy the parasite even though succumbing in the process as well. to study the possible in vivo participation of eosinophils in invasive amebiasis, we compared the induction of experimental amebic abscess of the liver (eaal) in gerbils (meriones unguiculatus) previously made eosinophilic (532 +/- 80 eosinophils/mm3) ...19958845666
rotaviruses as a cause of nosocomial, infantile diarrhoea in northern brazil: pilot study.faecal samples were obtained from 190 children, aged 0 to 5 years, admitted to a public hospital in belém, pará, brazil. these patients were placed in a pediatric ward with 40 beds distributed in six rooms. cases were classified into three groups: (a) nosocomial: children who developed gastroenteritis 72 hr or later after admission; (b) community-acquired: patients admitted either with diarrhoea or who had diarrhoea within 72 hr following admission; (c) non-diarrhoeic: those children who had no ...19958731371
a study of infective aetiology of chronic diarrhoea in children in amritsar.examination of 150 stool samples from children of less than 3 years of age of chronic diarrhoea showed the presence of various enteropathogens in 58.7% cases. cryptosporidium in pure form, entamoeba histolytica and giardia lamblia were detected in 1.3%, 2% and in 4% cases respectively. in 1.3% children candida albicans was isolated. the predominant bacterial isolate was enteropathogenic escherichia coli (21.4%). salmonella typhimurium, shigella and campylobacter were isolated in 8.6%, 4% and 0.7 ...19958834137
study of the incidence of intestinal and systemic parasitoses in a group of children with handicaps.a high incidence of parasitic infections was shown by the study of children with physical and psychic handicaps. in 231 children examined we diagnosed 294 parasitic infections as follows: 42 (18.1%) with giardia intestinalis 6 (2.59%) with entamoeba histolytica 36 (15.5%) with hymenolepis nana 21 (9.9%) with strongyloides stercoralis 16 (6.9%) with ascaris lumbricoides 92 (39.86%) with tricocephalus dispar 38 (16.4%) with enterobius vermicularis 7(3.03%) with cryptosporidium sp. also, by immunod ...19958993115
entamoeba histolytica trophozoites induce an inflammatory cytokine response by cultured human cells through the paracrine action of cytolytically released interleukin-1 alpha.infection with the protozoan parasite entamoeba histolytica results in a high mortality worldwide. to initiate infection, e. histolytica trophozoites in the bowel lumen penetrate the epithelium, and cause extensive lysis of host cells. the acute amebic lesions in animal models are characterized by infiltration with inflammatory cells, particularly neutrophils. the acute host response is likely important for determining whether the infection will spread systemically, but little is known regarding ...19957657801
importance of e. histolytica antigen in serodiagnosis and follow up of patients with amoebic liver abscess.this study is composed of a community based study and a hospital based study. the community based study was conducted on 200 apparently healthy individuals randomly chosen from rural areas. they were examined clinically, sonographically and parasitologically for e. histolytica cysts and by elisa for circulating amoebic antigen. they were negative for antigenaemia at 1/16 which was considered the diagnostic titre of amoebic hepatitis. the hospital based study was carried out on 27 patients suffer ...19957665944
a comparative study of experimental caecal amoebiasis and the evaluation of amoebicides.caecal amoebiasis models (mouse, hamster and rat) were compared for amoebic infection and chemotherapeutic evaluation using a pathogenic strain of entamoeba histolytica of human origin. caecal infection in the hamster was of the acute type, with a large number of amoebae in the caecal tissue, whereas the amoebae in rats were seen in the lumen, on the mucosal surface. amoebic lesions in the mouse caecum were of moderate severity. the mouse model responded to both metronidazole (tissue amoebicide) ...19957668916
the diagnosis of old and new gastrointestinal parasites.for the foreseeable future, light microscopy will continue to be the method of choice for diagnosing gastrointestinal parasites. however, in selected circumstances, the use of commercially available immunofluorescent kits will supersede the use of routine light microscopy for diagnosis of giardia lamblia and cryptosporidium parvum. these techniques may used to diagnose invasive amebic infections caused by e. histolytica in the future. pooling stool samples from the same or even different patient ...19957671576
transforming growth factor-beta 1 primes macrophages for enhanced expression of the nitric oxide synthase gene for nitric oxide-dependent cytotoxicity against entamoeba histolytica.nitric oxide (no) produced by activated macrophages is the major cytotoxic molecule for in vitro cytotoxicity against entamoeba histolytica trophozoites. transforming growth factor-beta 1 (tgf-beta 1) is a potent negative regulator of several macrophage functions, including no production. in this study, we investigated the effect of tgf-beta 1 on macrophage nitric oxide synthase (mac-nos) mrna expression and no production for macrophage cytotoxicity against e. histolytica trophozoites. tgf-beta ...19957558128
t-cell suppression and selective in vivo activation of th2 subpopulation by the entamoeba histolytica 220-kilodalton lectin.a 220-kda surface protein (l220) with lectin activity from entamoeba histolytica trophozoites has been characterized previously (j. l. rosales-encina, i. meza, a. lópez-de-león, p. talamás-rohana, and m. rojkind, j. infect. dis. 156:790-797, 1987). this molecule is involved in the adhesion process (i. meza, f. cázares, j. l. rosales-encina, p. talamás-rohana, and m. rojkind, j. infect. dis. 156:798-805, 1987) and is very immunogenic. in this work, we studied both the humoral and the cellular imm ...19957558304
interaction of laminin with entamoeba histolytica cysteine proteinases and its effect on amebic pathogenesis.the entamoeba histolytica 27-kda cysteine proteinases exhibit striking binding specificities for immobilized laminin over other components of the extracellular matrix, such as collagen and fibronectin. inactivation of the proteinase with the active-site inhibitor l-trans-epoxysuccinyl-leucylamido(4-guanidino)butane abolishes laminin binding by the enzyme, and conversely, laminin inhibits cleavage of a fluorogenic dipeptide substrate of the amebic cysteine proteinase, suggesting that the substrat ...19957558332
intestinal amebiasis: cyclic suppression of the immune response.the cellular immune response was evaluated in a c3h/hej mouse model of intestinal amebiasis at 5-60 days postinoculation with entamoeba histolytica. at various intervals, spleen lymphocytes were obtained from infected and noninfected control mice and cultured with concanavalin a (con a), pokeweed mitogen (pwm), or ameba antigen. e. histolytica infection induced a cyclic depression of dna synthesis when spleen lymphocytes were stimulated with a t-cell mitogen (con a), a t- and b-cell (pwm) mitoge ...19957567905
transfection and continuous expression of heterologous genes in the protozoan parasite entamoeba histolytica.to provide tools for functional molecular genetics of the protozoan parasite entamoeba histolytica, we investigated the use of the prokaryotic neomycin phosphotransferase (neo) gene as a selectable marker for the transfection of the parasite. an escherichia coli-derived plasmid vector was constructed (pa5'a3'neo) containing the neo coding region flanked by untranslated 5' and 3' sequences of an ent. histolytica actin gene. preceding experiments had revealed that amoebae are highly sensitive to t ...19957568055
a nuclear gene of eubacterial origin in euglena gracilis reflects cryptic endosymbioses during protist evolution.genes for glycolytic and calvin-cycle glyceraldehyde-3-phosphate dehydrogenase (gapdh) of higher eukaryotes derive from ancient gene duplications which occurred in eubacterial genomes; both were transferred to the nucleus during the course of endosymbiosis. we have cloned cdnas encoding chloroplast and cytosolic gapdh from the early-branching photosynthetic protist euglena gracilis and have determined the structure of its nuclear gene for cytosolic gapdh. the gene contains four introns which pos ...19957568085
parasitic infestation in acute appendicitis. 19957741603
clonal growth in petri dishes of entamoeba histolytica. 19957747296
amoebiasis in ethiopia.in a countrywide survey of amoebiasis, a total of 12,457 persons in 97 communities was stool examined by formol-ether concentration technique. the overall prevalences of entamoeba histolytica infections, as measured by rate of cyst-passers, in schoolchildren and non-school communities were 15.0% and 3.5%, respectively. slightly more females (18.4%) than males (14.2%) were infected among schoolchildren (p < 0.05) but the difference was not significant among non-school communities (p > 0.05). ther ...19957747328
severe vaginal infection with entamoeba histolytica in a woman who recently returned from mexico: case report and review.genital amebiasis is a rare complication of infection with entamoeba histolytica, even in areas where the pathogen is endemic. we describe a patient who apparently contracted intestinal amebiasis on a trip to mexico and who presented with ulcerative vulvovaginitis 2 months later. her condition rapidly progressed to severe necrotizing vulvovaginitis that required a radical vulvectomy. histopathologic examination of the surgical specimen revealed the presence of e. histolytica trophozoites. the pa ...19957756499
prevalence of intestinal parasites in saudi children: a community-based study.a community-based study was undertaken to determine the prevalence and types of intestinal parasites in the pediatric population of al-baha region, saudi arabia. stool samples were randomly collected from 19,939 children of whom 4208 (21.1%) were found to harbour intestinal parasites. the most affected age group was 5-9 years and the sex distribution was almost equal in all age groups. specific prevalence rates were giardia lamblia 9 per cent, entamoeba histolytica 5 per cent, hymenolepis nana 2 ...19957723130
the primary structure of an entamoeba histolytica enolase. 19957723780
[underestimation of intestinal protozoa as a cause of diarrhea in family practice]. 19957723885
entamoeba histolytica: increase of enterotoxicity and of 53- and 75-kda cysteine proteinases in a clone of higher virulence.we compared the enterotoxicity and cysteine proteinases (cp) of the low-virulence entamoeba histolytica hm1 strain with the highly virulent 1659 clone, derived from hm1 by hamster liver passages. enterotoxicity of 50,000 freeze-thawed trophozoites was determined on 0.28-cm2 intestinal segments mounted in ussing chambers; cp activity of nonidet-p40 amebal lysates was assayed by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and carbobenzoxy-l-arginine-l-arginyl-p-nitroaniline, ...19957729472
entamoeba histolytica: induction and isotype analysis of antibody producing cell responses in peyer's patches and spleen after local and systemic immunization in male and female mice.the purpose of this work was to determine if anti-amebic antibody producing cell responses could be elicited in peyer's patches and spleen in mice locally or systemically immunized with glutaraldehyde-fixed trophozoites of entamoeba histolytica (gft). the animals were inoculated with either a single or four doses of gft via intragastric, rectal, and intraperitoneal routes. the anti-amebic antibody producing cell responses were analyzed by a spot forming cell assay (elispot). the kinetics of anti ...19957729489
inositol(1,3,4,5) tetrakisphosphate plays an important role in calcium mobilization from entamoeba histolytica.calcium release from internal stores of entamoeba histolytica, a parasitic protozoan, was observed by measuring fluorescence of fura-2. emptying of inositol(1,4,5)trisphosphate (ins(1,4,5)p3)-sensitive calcium pools in permeabilized e. histolytica did not significantly affect subsequent calcium release by inositol(1,3,4,5)tetrakis-phosphate (ins(1,3,4,5)p4). similarly, prior depletion of ins(1,3,4,5)p4-sensitive stores did not have any influence on subsequent calcium release by ins(1,4,5)p3. the ...19957729520
entamoeba histolytica autochthonous isolates from mentally retarded italian patients.a total of 77 mentally retarded male inpatients residing in a psychiatric institution in northern italy were screened for the presence of stool parasites, entamoeba histolytica particularly. parasitological stool examination showed entamoeba spp. (e. histolytica and/or e. dispar) in 26 cases (33.7%). in vitro culture on robinson's medium was positive in 16 cases (61.1%); in 11 cases we could stabilize and clone the isolates and proceed to electrophoretic assays. in all cases, patterns of pathoge ...19957731923
cyclic nucleotide changes induced in human leukocytes by a product of axenically grown entamoeba histolytica that inhibits human monocyte locomotion.pulse exposure of human mononuclear phagocytes to the monocyte locomotion-inhibitory factor produced by entamoeba histolytica (i.e., the 369- to 765-da chromatographic fraction obtained from the supernatant fluid of axenically grown e. histolytica) led to a swift increase in the intracellular concentration of adenosine 3':5' cyclic monophosphate (camp). a weaker response was observed in human polymorphonuclear leukocytes, the locomotion of which, however, is not inhibited by this amebic factor. ...19957731924
intestinal parasitic infections in the residents of an emigration camp in tijuana, mexico.we examined stool specimens of the residents in the emigration camp in tijuana, mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in february and july 1992. out of 92 examined samples, number of positive was 49 (53.3%). while number of cumulative positive was 66 (71.7%). cysts of entamoeba coli (29.3%) giardia lamblia (9.8%), entamoeba histolytica (7.6%), and eggs of taenia spp. (6.5) were most frequently observed. filtered water supply and chemotherapy ...19957735788
the antiamoebic effect of a crude drug formulation of herbal extracts against entamoeba histolytica in vitro and in vivo.the antiamoebic effect of a crude drug formulation against entamoeba histolytica was studied. in the traditional system of medicine in india, the formulation has been prescribed for intestinal disorders. it comprises of five medicinal herbs, namely, boerhavia diffusa, berberis aristata, tinospora cordifolia, terminalia chebula and zingiber officinale. the dried and pulverized plants were extracted in ethanol together and individually. in vitro amoebicidal activity was studied to determine the mi ...19957739226
the serine-rich entamoeba histolytica protein is a phosphorylated membrane protein containing o-linked terminal n-acetylglucosamine residues.previously, we described the isolation of a cdna clone and the gene encoding a protective antigen of the protozoan parasite entamoeba histolytica, the serine-rich entamoeba histolytica protein (srehp). the derived amino acid sequence of the srehp cdna clone was remarkable for a high serine content (52/233 amino acids), a putative signal sequence, multiple hydrophilic dodecapeptide and octapeptide tandem repeats, and a hydrophobic c-terminal putative membrane-spanning region. here, we show that s ...19957876162
a recombinant cysteine-rich section of the entamoeba histolytica galactose-inhibitable lectin is efficacious as a subunit vaccine in the gerbil model of amebic liver abscess.the 170-kda subunit of the galactose-inhibitable adherence lectin of entamoeba histolytica mediates attachment to colonic mucins and host cells. the dna fragment encoding the 170-kda subunit was produced by polymerase chain reaction (pcr) and divided into four sections by restriction endonucleases. the third section (designated lc3, base pairs 2273-3397) encodes a cysteine-rich fusion protein that was recognized by adherence-inhibitory anti-lectin monoclonal antibodies and serum antibodies from ...19957876611
[underestimation of intestinal protozoa as a cause of diarrhea in family practice].to assess the frequency of intestinal protozoa in stool samples of patients with diarrhoea in general practice.19957877701
oral immunization with the dodecapeptide repeat of the serine-rich entamoeba histolytica protein (srehp) fused to the cholera toxin b subunit induces a mucosal and systemic anti-srehp antibody response.the intestinal protozoan parasite entamoeba histolytica causes amebic dysentery, a major cause of morbidity worldwide. the induction of a mucosal antibody response capable of blocking amebic adhesion to intestinal cells could represent an approach to preventing e. histolytica infection and disease. here we describe the expression of a chimeric protein containing an immunogenic dodecapeptide derived from the serine-rich e. histolytica protein (srehp), fused to the cholera toxin b subunit (ctxb). ...19957890393
role of the entamoeba histolytica cysteine proteinase in amebic liver abscess formation in severe combined immunodeficient mice.evidence from in vitro studies suggest that the entamoeba histolytica cysteine proteinase plays a role in the tissue lysis and cytopathic effects seen in invasive amebiasis. we used affinity-purified antibodies against a recombinant e. histolytica cysteine proteinase to demonstrate that the proteinase is present extracellularly in amebic liver abscesses in mice with severe combined immunodeficiency (scid mice). treatment of e. histolytica trophozoites with specific cysteine proteinase inhibitor ...19957890426
high affinity binding of the entamoeba histolytica lectin to polyvalent n-acetylgalactosaminides.entamoeba histolytica trophozoites initiate pathogenic colonization by adherence to host glycoconjugates via an amebic surface lectin which binds to galactose (gal) and n-acetylgalactosamine (galnac) residues. monovalent and multivalent carbohydrate ligands were screened for inhibition of e. histolytica lectin-mediated human red cell hemagglutination, revealing that: (i) the synthetic multivalent neoglycoprotein galnac39bsa (having an average of 39 galnac residues linked to bovine serum albumin) ...19957890626
identification of various circular dna molecules in entamoeba histolytica. 19957895848
protection of gerbils from amebic liver abscess by immunization with recombinant entamoeba histolytica 29-kilodalton antigen.the goal of our study was to obtain a highly conserved entamoeba histolytica recombinant antigen for study as a subunit amebiasis vaccine. we screened a uni-zap cdna library of e. histolytica (strain hm1:imss) with human immune sera and isolated a dominant 804-bp cdna clone. a 33-kda fusion protein expressed from the cdna clone was determined by monoclonal antibody binding, dna hybridization, and nucleotide sequence to be the complete e. histolytica 29-kda antigen. serum antibodies to the recomb ...19957822012
immunization of rats with the 260-kilodalton entamoeba histolytica galactose-inhibitable lectin elicits an intestinal secretory immunoglobulin a response that has in vitro adherence-inhibitory activity.the 260-kda galactose-inhibitable lectin of entamoeba histolytica mediates binding of amebic trophozoites to purified colonic mucins and intestinal epithelial cells. parenteral immunization of lewis rats with immuno-affinity-purified lectin with freund's adjuvant and then intra-peyer's patch inoculation of lectin with cholera toxin b subunit as adjuvant elicited a significant anti-lectin secretory immunoglobulin a response in the bowel lumen. purified intestinal secretory immunoglobulin a from t ...19957822040
polymerase chain reaction-solution hybridization enzyme-linked immunoassay (pcr-shela) for the differential diagnosis of pathogenic and non-pathogenic entamoeba histolytica. 19957778145
[nationwide survey of the distribution of human parasites in china--infection with parasite species in human population].the infection rate of main species of parasites and their character by first nationwide survey of human parasites was made. the overall infection rate of human intestinal parasite and the infection rate of most species of parasites were higher in females than that in males. the infection rate according to the age group, the highest infection rate was found in the group aged 5-14 years. with regard to the relation between parasitic infections and occupations of the infected persons, the highest i ...19957788888
[in vitro effect of metronidazole ester on trichomonas vaginalis and entamoeba histolytica].metronidazole ester, a new nitroimidazole drug, was synthesized by the department of physical chemistry, school of pharmacy, shanghai medical university. the trichomonadicidal and amoebicidal activity of metronidazole ester was evaluated in vitro by the cultivation of trichomonas vaginalis and entamoeba histolytica at different drug concentrations. the results indicated that the 100% lethal concentration for t. vaginalis and e. histolytica was 2.6 micrograms/ml and 40 micrograms/ml, respectively ...19957788891
diagnosis of invasive amoebiasis: renaissance of the morphology era. 19957797138
cloning and sequencing a putative pyrophosphate-dependent phosphofructokinase gene from entamoeba histolytica.pyrophosphate-dependent phosphofructokinase (ppi-pfk) gene from entamoeba histolytica was cloned from its genomic library and sequenced. the open reading frame has 1149 bp and codes for a protein of 41.5 kda. the deduced amino acid sequence of e. histolytica ppi-pfk has 25 to 28% identity to the ppi-pfks from propionibacterium freudenreichii, naegleria fowleri and potato. the amino acid residues known to contribute to the active site of ppi-pfk from p. freudenreichii are conserved.19957841199
comparisons of ribosomal rna sequences from amitochondrial protozoa: implications for processing, mrna binding and paromomycin susceptibility.the amitochondrial (a-mt) protozoa include four groups of organisms that are of interest as important human parasites and as probable descendents of the earliest branches of eukaryotic evolution. these organisms have not been directly compared in terms of structure and function of a specific molecule. we sequenced portions of their rrna-encoding genes coding for the internal transcribed spacers (its1 and 2) and adjoining small subunit (ss), 5.8s and large subunit (ls) rrnas. included are sites f ...19957828924
genetic differentiation of pathogenic and nonpathogenic strains of entamoeba histolytica by random amplified polymorphic dna polymerase chain reaction.the random amplified polymorphic dna polymerase chain reaction (rapd-pcr) method was used to compare pathogenic and nonpathogenic strains of entamoeba histolytica. dna polymorphisms were detected among the different strains and dendrograms were constructed by phylip and paup analyses to study the relationship of the strains. both analyses resulted in identical results, which indicated that pathogenic strains of e. histolytica are closely related and clearly separated from the nonpathogenic strai ...19957770427
entamoeba histolytica suppresses gamma interferon-induced macrophage class ii major histocompatibility complex ia molecule and i-a beta mrna expression by a prostaglandin e2-dependent mechanism.the surface expression of class ii major histocompatibility complex immune-associated (ia) antigen is a principal accessory function of macrophages for antigen-specific t-cell activation and immunoregulation. to explore the mechanisms of impaired cell-mediated immunity in invasive amebiasis, we investigated the effects of entamoeba histolytica proteins on gamma interferon (ifn-gamma)-induced ia expression by murine bone marrow-derived macrophages. pretreatment of macrophages with secreted (condi ...19957868232
molecular cloning of a 30-kilodalton lysine-rich surface antigen from a nonpathogenic entamoeba histolytica strain and its expression in a pathogenic strain.a monoclonal antibody (mab), 318-28, that specifically reacts with a 30-kda antigen present on membrane surfaces of all nonpathogenic (np) entamoeba histolytica strains tested and which did not react with pathogenic (p) strains was used for the isolation of the cdna coding for this antigen from an expression library of an np e. histolytica strain. the deduced amino acid composition was rich in lysine residues (14.5%), with some sequence similarity to a polyadenylate-binding protein. southern and ...19957868264
amebiasis from the "miraculous water of tlacote". 19957845445
mexico. a stubborn amoeba takes center stage. 19957846526
analysis of the 170-kda lectin gene promoter of entamoeba histolytica.the promoter region driving the gene for the 170-kda heavy subunit of the entamoeba histolytica galactose-inhibitable lectin was analysed by transient transfection using the chloramphenicol acetyltransferase gene as reporter. s1 mapping confirmed our previous notion that the promoter is located within a 1.35-kb intergenic sequence preceding the structural lectin gene. transcripts derived from the chloramphenicol acetyltransferase gene of transfected trophozoites were found to be polyadenylated a ...19958538679
free radical detoxification in giardia duodenalis.non-denaturing polyacrylamide gels were used to analyse superoxide dismutase (sod), catalase, peroxidase, nadh oxidase and nadh peroxidase in the microaerophilic protozoan parasite giardia duodenalis. a cytosolic h2o-producing nadh oxidase and membrane-associated nadh peroxidase were readily detected from g. duodenalis. in all giardia strains investigated the nadh oxidase was present in high levels (1.2-2 u (mg protein)-1). using the same technique, nadh oxidase activity was also detected in the ...19958538699
zoonotic intestinal parasites of hamadryas baboons papio hamadryas in the western and northern regions of saudi arabia.six hundred and thirty-three faecal samples were randomly collected and examined for ova and cysts of intestinal parasites from five groups of hamadryas baboons of different population densities, with different human contact and in different ecological conditions (al-baha, turabah and al-taif in south-western and al-rihat and al-akhal in north-western saudi arabia). nine parasites were recorded (giardia lamblia, entamoeba histolytica, escherichia coli, balantidium coli, enterobius sp., trichuris ...19958544227
carbohydrate epitopes of entamoeba histolytica cell surface glycoproteins are major targets of the human humoral response.the antigens of entamoeba histolytica recognized by antibodies in 11 individual sera from patients treated for amebic liver abscess were determined both by immunoprecipitation of metabolically-radiolabeled whole trophozoite proteins and by immunoblotting.collectively, twenty-s even antigens ranging from 167 to 21 kda were detected in immunoblots of whole trophozoite extracts; eight of these were recognized by all tested patient sera. immunoprecipitation studies also revealed a complex amebic ant ...19958546039
the seroprevalence of ten zoonoses in two villages of crete, greece.the seroprevalence and incidence of 10 zoonoses due to rickettsia typhi, r. conorii, coxiella burnetii, burcella sp., borrelia sp., toxoplasma sp., leishmania sp., entamoeba histolytica, echinococcus granulosus and fasciola hepatica were studied in an animal husbandry and a farming village in crete, greece. the serum conversion incidence of each infectious agent was determined by testing 2 blood samples, collected in 1985 and in 1987. the surveillance was conducted using detailed transparent map ...19958549708
the relationship of water sources and other determinants to prevalence of intestinal protozoal infections in a rural community of saudi arabia.a study was carried out in a rural area of asir region in southwest of saudi arabia where information on the types of domestic water supply and sociodemography in relation to intestinal protozoal infections were obtained from 1417 inhabitants (81.4% of the total) of nine villages. stool samples were collected from the study population and examined for intestinal parasites. overall, the prevalence rates of infection with the common water-borne parasites, giardia lamblia and entamoeba histolytica ...19958550870
the association of the amoebic colitis and chronic ulcerative colitis.three patients with idiopathic ulcerative colitis and infection of entamoeba histolytica were reviewed. they represented three different relationships between the two conditions, vis asymptomatic carrier, coexisting infection and superinfection causing exacerbation of colitis. a two-way relationship between amoebic colitis and ulcerative colitis has been discussed and the possible mechanisms in the literature have been reviewed. in patients with a short history of diarrhoea and in tropical count ...19958553098
entamoeba histolytica axenic growth improvement by ox bile.axenic entamoeba histolytica cultures, grown in pehps medium, showed increasing yields and growth velocity when added with 0.03 to 0.6 g/l gallbladder ox bile, while higher doses were toxic for amebas. the highest density (505 +/- 29 x 10(3) trophozoites/ml) and shortest duplication time (dt = 10.74 +/- 0.2 h) corresponded to cultures added with 0.24 g bile/l. their yields were 1.74 and 3.34 times higher, respectively, than those which were reached by the non-added pehps controls and by growth o ...19958555742
prevalence of antibodies against entamoeba histolytica in mexico measured by elisa.the prevalence of antibodies against entamoeba histolytica was studied in the mexican population using an immunoenzyme assay in solid phase (elisa) and semiautomatic equipment. the antigen was a mixture of membrane proteins obtained by triton x-100 extraction from an axenic culture of entamoeba histolytica hm1-imss. the method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. from the 60,538 samples supplied by the national seroepidemiology ...19958557086
the basic isoform of profilin in pathogenic entamoeba histolytica. cdna cloning, heterologous expression, and actin-binding properties.in the human parasite entamoeba histolytica, components of the cytoskeleton are involved in the pathogenicity by their contribution to immune evasion by antibody capping and shedding. in this study, we focus on profilin as a central regulatory component of the cytoskeleton. profilin was isolated from trophozoites of the pathogenic e. histolytica strain sfl-3, and partial amino acid sequences were used to devise a probe for isolating a profilin cdna. the deduced complete primary structure was div ...19958521867
[amebic liver abscess: review of 13 cases].amebian hepatic abscess (aha) is the most frequent extraintestinal localization of infection by entamoeba histolytica. despite being a disease mainly of tropical zones, it is currently also observed with higher frequency in spain. thirteen cases of aha diagnosed in the authors' hospital over the last 11 years were retrospectively analyzed comparing the data in this series with that of other published series and undertaking a review of this subject. the diagnosis of aha was established on the bas ...19958523930
intestinal parasites in school food handlers in the city of uberlândia, minas gerais, brazil.in order to verify the presence of intestinal parasites in food handlers, stool samples were collected from 104 cooks and their helpers that were working in food preparation in 20 public elementary schools, in various areas of the city of uberlândia, minas gerais, brazil. the samples were collected during the months of november and december, 1988, in plastic flasks containing a 10% formaldehyde solution and processed by the hoffmann, pons & janer method. the sediment was examined using triplicat ...19958525262
influence of bacteria upon cytopathic effect and erythrophagocytosis of different axenic strains of entamoeba histolytica.at this moment, the duality of species suggested for e. histolytica is being considered for discussion. in order to contribute to settling this question, we investigated the possibility of conversion of avirulent ameba to virulent ones, as well as, the possibility of increasing virulence of virulent strains, by means of association with bacteria. five strains of e. histolytica were employed, two of them regarded as avirulent and three virulent ones. amebas were associated with the bacteria esche ...19958525263
opportunistic and non-opportunistic parasites in hiv-positive and negative patients with diarrhoea in tanzania.a survey on intestinal parasites in a rural area of tanzania revealed the presence of eight protozoa and seven helminths in 287 subjects (81.8%). the prevalence of entamoeba histolytica and ascaris lumbricoides was higher in hiv-negative than in hiv-positive patients (p < 0.01; p < 0.04) (25.1% and 12.5% for e. histolytica; 10.5% and 3.7% for a. lumbricoides). on the other hand, cryptosporidium parvum, isospora belli and strongyloides stercoralis prevalence was higher in hiv-positive than in hiv ...19958525281
prevalence of intestinal parasitic infections among asian female house keepers in abha district, saudi arabia.a group of 5,518 female asian house keepers working in abha district of saudi arabia was examined (1990 through 1992) to determine the prevalence of intestinal parasitic infections. they came from indonesia, sri lanka, philippines and thailand. fresh stool specimens were obtained in special containers and examined by light microscopy of wet smears in normal saline and lugoll's iodine solution within one hour of collection. the study revealed an overall prevalence of 46.5% which was higher than t ...19958525400
entamoeba histolytica adherence: inhibition by iga monoclonal antibodies. 19958526018
a novel transcribed repeat element from entamoeba histolytica.we have identified an unusual 0.55-kb dna repeat element specific to entamoeba histolytica (eh) which we call interspersed element (ie). the ie is a common feature in independently isolated genomic and cdna fragments. hybridization of labeled ie sequences to trophozoite dna, rna and first-strand cdna prepared from poly(a)-enriched mrna indicate that the ie are reiterated about 500 times per eh trophozoite and that one or more can be found as rna transcripts. these features and the degree of cons ...19958529889
viral diarrhoea in a rural coastal region of karnataka india.a total of 106 children below 5 years of age admitted to the kasturba medical college hospital manipal karnataka (south india) were investigated over a period of 6 months to determine the aetiological role of viruses in acute diarrhoea. viral aetiological agents isolated were rotaviruses in 12 (11 per cent) cases, adenoviruses in 3 (3 per cent) cases, coronavirus and astroviruses in two (2 per cent) cases each. non-viral isolates were cryptosporidium and salmonella typhimurium in two cases each, ...19958531264
amoebicidal compounds from medicinal plants.a series of the natural constituents with amoebicidal activity isolated from several medicinal plants is shown. a list of the medicinal plants potentially active as amoebicide and/or against dysentery also is demonstrated. the present data grouping of the natural compounds and medicinal plants can be an important source of information for the selection of research plant material by the investigators interested in the discovery of new biologically active compounds as amoebicide.19958532364
evaluation of three serological tests for the detection of antiamebic antibodies applied to sera of patients from an area endemic for amebiasis.two enzyme immuno assays based on a single recombinant entamoeba histolytica antigen (p1-eia) or soluble e. histolytica extract (sa-eia) as well as a latex agglutination test using an e. histolytica membrane fraction (m-la) were evaluated for its use to detect anti-amebic serum antibodies in patients from durban, south africa, an area endemic for amebiasis. in a previous study, all three test systems were found to be reliable in terms of sensitivity and specificity when applied to sera of europe ...19958533021
[clinico-epidemiological implications of autochthonous infection caused by entamoeba histolytica]. 19958534547
prevalence of intestinal parasitic infection in five farms in holambra, são paulo, brazil.a parasitological survey was carried out on 222 inhabitants of five farms in holambra, located 30 km north of campinas, são paulo, brazil, on october 1992. approximately 70% of the inhabitants were found to be infected with at least one species of intestinal parasite. the positive rates of 6 helminths and 7 protozoan species detected are as follows: 5.4% ascaris lumbricoides; 8.6% trichuris trichiura; 19.8% necator americanus; 10.4% strongyloides stercoralis; 1.4% enterobius vermicularis; 0.9% h ...19957569635
comparison of two media for the isolation and short-term culture of entamoeba histolytica and e. dispar. 19957570875
transmission of entamoeba histolytica within a family complex.a limited outbreak of symptomatic intestinal and extraintestinal amoebiasis within a family complex is described. the infection was almost certainly transmitted by a philippino housemaid, who was an asymptomatic carrier of entamoeba histolytica infection acquired in her native country. starch-gel electrophoresis showed isoenzyme patterns characteristic of pathogenic zymodeme xix in all the amoebic isolates.19957570880
[viruses of parasitic protozoa].the authors present the actual review on several publications concerning the molecular characterizations of the viruses found in parasitic protozoa such as giardia, trichomonas, leishmania and entamoeba histolytica. all of the rna viruses observed in parasitic protozoa showed several similarities and did not considerably differ from the viruses found in simple eukaryotic cells; they closely correspond to dsrna viruses of yeast. the supposition that the protozoan symbionts detected in laboratorie ...19957571630
[histological and histochemical investigations of large and small intestine in guinea pigs infected by entamoeba histolytica].in order to gain better knowledge about pathomechanisms of amebiasis, histological and histochemical studies were performed on large and small intestine of guinea pigs infected by ps-2 entamoeba histolytica strain. results of these studies showed that the presence of e. histolytica in large intestine caused also pathomorphological changes of small intestine: partial atrophy of villi, epithelium destruction, epithelial metaplasia, lacteral dilation, infiltration of mucous membrane by lymphocytes, ...19957571633
alcohol dehydrogenase: multiplicity and relatedness in the solvent-producing clostridia.alcohol dehydrogenase (adh) is a key enzyme for the production of butanol, ethanol, and isopropanol by the solvent-producing clostridia. initial studies of adh in extracts of several strains of clostridium acetobutylicum and c. beijerinckii gave conflicting molecular properties. a more coherent picture has emerged because of the following results: (i) identification of adhs with different coenzyme specificities in these species; (ii) discovery of structurally conserved adhs (type 3) in three sol ...19957576768
elucidation of the dna synthetic cycle of entamoeba spp. using flow cytometry and mathematical modeling.we developed a method to study the dna synthetic cycles of entamoeba histolytica and entamoeba invadens by flow cytometry (fcm) based on a preparative procedure to reduce both high levels of natural fluorescence and non-specific adsorption of fluorochromes. we modeled g1, s, and g2 phases as a series of overlapping gaussian curves. both e. histolytica and e. invadens displayed g1, s, and g2 proportions that are consistent with eukaryotic cell populations in exponential or stationary growth phase ...19957581336
lipophosphoglycan is present in distinctly different form in different entamoeba histolytica strains and absent in entamoeba moshkovskii and entamoeba invadens.lipophosphoglycan has recently been demonstrated on the cell surface of entamoeba histolytica strain hm-1:imss. a monoclonal antibody against this molecule had failed to react with some other strains of e. histolytica, including the strain rahman. to determine if a structurally distinct lipophosphoglycan existed in rahman, [3h]galactose-labeled glycoconjugates were electrophoresed through sodium dodecyl sulfate polyacrylamide gel electrophoresis. the electrophoretic pattern in rahman was very di ...19957581337
the primary structure of an entamoeba histolytica beta-hexosaminidase a subunit.an entamoeba histolytica gene (hex-a1) that encodes subunit a of the lysosomal enzyme beta-hexosaminidase has been cloned and sequenced. the inferred 59 kda hex-a1 protein has the same molecular weight and 32% amino acid residue identity with the human and mouse proteins and 28% residue identity with the dictyostelium protein. northern blot analysis identified a mrna of approximately 1.6 kb, which is in agreement with the expected size of a mrna encoding the 522 amino acid hex-a1 protein. southe ...19957581340
identification of immunogenic epitopes of the 170-kda subunit adhesin of entamoeba histolytica in patients with invasive amebiasis.entamoeba histolytica causes amebic dysentery (ad) and liver abscess (ala). little is known about protective immunity to amebiasis, and studies in this area have been complicated by the paucity of defined ameba antigens. we examined the proliferative responses of peripheral blood mononuclear cells (pbmc) from patients with ad and ala to a recombinant protein containing a portion of the 170 kda adhesin of e. histolytica (170cr), and to two synthetic peptides (1 and 2) derived from the 170 kda seq ...19957581341
entamoeba histolytica and giardia lamblia infections: current diagnostic strategies.entamoeba histolytica and giardia lamblia constitute, in a world context, the two commonest intestinal protozoan parasites to affect man. therefore accurate diagnosis is of paramount importance if resultant infections are to be adequately managed. demonstration of the cyst or trophozoite stage in a faecal sample(s) (several newer techniques are available) remains the lynch-pin of diagnostic strategies; however, excretion of cysts, especially, is intermittent and evidence of infection is not alwa ...19957582374
[detection of pathogenic entamoeba histolytica dna in liver abscess aspirates with polymerase chain reaction].polymerase chain reaction (pcr) was used to diagnose amebic liver abscess by detecting pathogenic entamoeba histolytica dna in liver aspirates from patients with liver abscess. oligonucleotide primers specific for gene encoding of the 30,000 molecule of pathogenic entamoeba histolytica were used in the test. liver aspirates from 23 cases with amebic liver abscess as evidenced by typical clinical findings or very high titres of anti-e. histolytica antibodies with elisa were found to be positive w ...19957587609
increase in mrna of multiple eh pgp genes encoding p-glycoprotein homologues in emetine-resistant entamoeba histolytica parasites.with the goal of understanding possible mechanisms of drug resistance by the protozoan parasite entamoeba histolytica (eh), two novel eh p-glycoprotein (pgp) genes (eh pgp5 and eh pgp6) were sequenced, and the expression of four eh pgp genes determined in wild-type (wt) clone a and emetine-resistant (emr) clone c2 amebae. the eh pgp5 gene encodes a 1301-amino acid (aa) protein that is similar to those of eh pgp1 (64% aa identity), eh pgp2 (61%), eh pgp6 (39%) and homo sapiens mdr (multidrug-resi ...19957590312
entamoeba histolytica stimulates the unstable transcription of c-fos and tumour necrosis factor-alpha mrna by protein kinase c signal transduction in macrophages.macrophages play an important role in the control of and resistance to entamoeba histolytica (e. histolytica). however, e. histolytica infections are characterized by suppression of cell-mediated immunity. to elucidate the molecular mechanisms whereby amoebae modulate host defences, we investigated whether the parasite elicits the 'immediate early' gene c-fos and cytokine tumour necrosis factor-alpha (tnf)-alpha mrna and determined the signal transduction pathways involved in naive bone marrow-d ...19957590881
contact-dependent transfer of the galactose-specific lectin of entamoeba histolytica to the lateral surface of enterocytes in culture.in a study to investigate early interactions of entamoeba histolytica with epithelial cell monolayers, we found that a monoclonal antibody (mab), cd6, against an ameba surface antigen recognized the lateral surface of epithelial cells after coculture with trophozoites. display of the cd6 antigen on the epithelial cells necessitated contact with active trophozoites. it was found neither at 4 degrees c, nor with prefixed trophozoites, nor with trophozoite-conditioned media, nor when a filter preve ...19957591055
myosin ii is involved in capping and uroid formation in the human pathogen entamoeba histolytica.the redistribution and capping of surface receptors on the human pathogen entamoeba histolytica was observed in the presence of concanavalin a (cona). capping was correlated with plasma membrane folding towards the rear of the amoeba and with uroid formation. the uroid is thought to play a role in the escape of amoebae from the host immune response. to localize myosin ii during capping, amoebae were incubated in the presence of cona and then analyzed by microscopy. myosin ii was three times more ...19957591071
amoebicidal in vitro activity shown by some metronidazole analogues: biological response-reduction potential correlation. 19957597003
the extracellular neutral cysteine proteinase of entamoeba histolytica degrades anaphylatoxins c3a and c5a.we have shown previously that the extracellular cysteine proteinase of entamoeba histolytica trophozoites activates the alternative pathway of complement by specifically cleaving c3. this unique mechanism of complement activation leads to passive lysis of nonpathogenic, but not of pathogenic strains. in an attempt to investigate the relationship between the cleavage of complement components c3 and c5 and the pathogenesis of amebiasis, we investigated the production of the anaphylatoxins c3a and ...19957602103
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