Publications

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 ...	1995	7567905
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 ...	1995	7568055
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 ...	1995	7568085
prevalence and pathogenicity of entamoeba histolytica in three different regions of pernambuco, northeast brazil.	parasitological examinations were carried out on 663 individuals of three different cities of pernambuco state, northeastern brazil: recife, palmares and bodocó. the population from a drought area of pernambuco state, bodocó, was investigated for amoebiasis and compared with recife, metropolitan city (about 1.3 million of inhabitants) and another inland community, palmares, located inside of the sugar-cane plantation region of the state. no evidence of invasive strains of e. histolytica were fou ...	1994	7569626
entamoeba histolytica: detection of coproantigens by purified antibody in the capture sandwich elisa.	a sensitive and specific capture sandwich elisa (cse) was developed using polyclonal purified rabbit antibodies against three different axenic strains of entamoeba histolytica: csp from brazil and hm1 - imss from mexico, for the detection of coproantigens in fecal samples. immunoglobulin g (igg) against e. histolytica was isolated from rabbits immunized with throphozoites whole extract in two stages: affinity chromatography in a column containing e. histolytica antigens bound to sepharose 4b was ...	1994	7569629
use of monoclonal anti-light subunit antibodies to study the structure and function of the entamoeba histolytica gal/galnac adherence lectin.	adherence of entamoeba histolytica trophozoites to host cells is mediated by a galactose (gal) and n-acetylgalactosamine (galnac)-specific surface lectin. the lectin is a heterodimeric protein composed of heavy (170 kda) and light (35-31 kda) subunits linked by disulfide bonds. polyclonal and monoclonal antibodies (mab) raised against a light subunit-glutathione-s-transferase fusion protein were used to probe its structure and function. four light subunit-specific mab were produced which recogni ...	1994	7696848
[epidemiology and etiology of infectious diarrheas. the case of mexico].	gastrointestinal infections represent a health problem. it is estimated that 1647 million cases of diarrhea and 3.2 million deaths due to this cause occur among children less than five years of age per year. those belonging to this age group have 15 times more risk of dying because of diarrhea. cases of liquid acute diarrhea with blood represent 80% of cases, diarrhea with blood represent 10%. most frequent causes of liquid diarrhea are enterotoxigenic escherichia coli and rotaviruses and most f ...	1994	7701141
control of an amoebiasis outbreak in the philippi area near cape town.	previous studies in durban have shown that serological investigations, in combination with iso-enzyme electrophoresis, are invaluable for monitoring the endemicity of pathogenic strains of entamoeba histolytica. we therefore proposed that antibody profiles could be used to detect epidemic situations. an outbreak of amoebiasis in the normally non-endemic philippi area near cape town provided an opportunity for testing this hypothesis. seven of 9 patients presenting at a district hospital with inv ...	1994	7709300
[comparison of intestinal parasite infestation indexes among hiv positive and negative populations].	this study was carried out on two groups of patients treated at the josé de san martín clinical hospital. one group was composed of 82 hiv-seropositive patients with no signs of diarrhea, and another one of 300 patients, not suspected of hiv infection, was considered as "control population". stool samples were collected from each patient and examined for intestinal parasites. these determinations were carried out at the department of clinical biochemistry, in the same hospital. three specimens w ...	1994	7715428
amoebapores, a family of membranolytic peptides from cytoplasmic granules of entamoeba histolytica: isolation, primary structure, and pore formation in bacterial cytoplasmic membranes.	three peptides with pore-forming activity were isolated from the cytoplasmic granules of pathogenic entamoeba histolytica by acidic extraction, gel filtration and reversed-phase high-performance liquid chromatography. partial amino acid sequence analysis of the three active peptides revealed that the most abundant of them was amoebapore and the other two were isoforms thereof. cloning and sequencing of genomic dna resolved the amino acid sequence of the two newly recognized peptides. the three p ...	1994	7715451
complement sensitivity of entamoeba histolytica and various nonpathogenic amoeba species.	culture forms of the potentially pathogenic entamoeba histolytica were compared to those of the nonpathogenic species of e. dispar, e. hartmanni, e. coli, endolimax nana, and e. moshkovskii regarding the sensitivity to lysis by human complement activated through the alternative pathway. e. dispar was found unique in its complement resistance; all other nonpathogenic isolates resembled e. histolytica in that they were complement sensitive. thus, a state of complement sensitivity is not a particul ...	1994	7716404
[a coprological study of intestinal infections in northern morocco (provinces of tangier, tetuán and larache)].	an epidemiological study on intestinal parasites has been carried out in northern morocco (province of tangier, tetuan and larache). a comparative study has been made at a provincial, city and areas (urban and rural) level. also the spi (simple parasitism index) and the cpi (comparative parasitism index) distribution.	1994	7716431
[report on the first nationwide survey of the distribution of human parasites in china. 1. regional distribution of parasite species].	a nationwide (taiwan province not included) survey of the distribution of human parasites in china during 1988-1992 was conducted under the auspices of the ministry of public health, with stratified masses randomly sampling. a total of 2,848 pilot sites in 726 counties with a population of 1,477,742 were surveyed, according to unified standard, unified diagnostic method and control quality. the overall infection rate of parasites was 62. 632%. among them, the infection rate was over 50% in 17 pr ...	1994	7720194
[effect of indirect fluorescent antibody test for the diagnosis of amoebiasis].	indirect fluorescent antibody test (ifat) was performed by the method of [symbol: see text] (1971) with some slight modifications for the diagnosis of amoebiasis. the antigen used was prepared from 48-hour culture of entamoeba histolytica (strains g2, g3, and g5) in las diphasic medium and only those amoebae clinging the culture were collected. the serum samples or blood drops on filter paper were positive by the improved ifat in all of the 54 cases of amoebic liver abscess and the positive reac ...	1994	7720200
[in vivo experimental models of amebiasis].	in vivo experimental models for amebiasis have provided important information about the mechanisms of host-parasite interaction which determine the production of disease. in the laboratory, several species of rodents have been used to study the intestinal and hepatic amebiasis. for the former, the model of "washed-closed cecal loop" in guinea-pig and hamster has been useful to study the early invasive events. in gerbils we also produced early intestinal lesions by intracecal inoculation with mon ...	1994	7557059
invasion and metastasis mechanisms in entamoeba histolytica and cancer cells. some common cellular and molecular features.		1994	7510034
cd59 (protectin) molecule, resistance to complement, and virulence of entamoeba histolytica.		1994	7512288
the pore-forming peptide of entamoeba histolytica, the protozoan parasite causing human amoebiasis.	amoebapore, the pore-forming peptide of e. histolytica has been isolated and its structure elucidated on the cdna and protein level. the peptide is composed of 77 amino acid residues including six cysteine residues and has a molecular mass of 8244 da. the primary translation product contains a signal sequence of 21 mostly hydrophobic amino acid residues. the active peptide has been located in the cytoplasmic granules of the amoebae. circular dichroism spectroscopy revealed an all alpha-helical c ...	1994	7512763
tumor necrosis factor alpha augments nitric oxide-dependent macrophage cytotoxicity against entamoeba histolytica by enhanced expression of the nitric oxide synthase gene.	nitric oxide (no measured as nitrite, no2-) is the major effector molecule produced by activated macrophages for in vitro cytotoxicity against entamoeba histolytica trophozoites. in this study, we determine whether tumor necrosis factor alpha (tnf-alpha) produced by activated bone marrow-derived macrophages (bmm) is involved in the induction of the inducible no synthase gene (mac-nos) for no-dependent amebicidal activity. tnf-alpha alone did not directly induce macrophage no2- production to kill ...	1994	7513301
short report: detection of entamoeba histolytica and e. dispar directly in stool.	current diagnosis of entamoeba histolytica infection requires the direct microscopic identification of the parasite, a technique that is insensitive and cannot distinguish pathogenic e. histolytica from noninvasive e. dispar. enzyme-linked immunosorbent assay (elisa) antigen detection tests were developed to distinguish e. histolytica from e. dispar infection in stool specimens. the elisa result for e. histolytica antigen was positive in 26 of 27 e. histolytica-positive stool specimens, three of ...	1994	7515594
pore-forming peptide of entamoeba histolytica. significance of positively charged amino acid residues for its mode of action.	amoebapore is a 77-residue pore-forming peptide from entamoeba histolytica with antibacterial and cytolytic properties. it contains eight lysine residues and one histidine residue. chemical modifications of amoebapore with various reagents affecting either both types of cationic residues or lysine and histidine residues separately resulted in virtually complete loss of pore-forming activity. the activity was restored by reversal of modifications. whereas amoebapore was no longer capable of bindi ...	1994	7525351
entamoeba histolytica modulates the nitric oxide synthase gene and nitric oxide production by macrophages for cytotoxicity against amoebae and tumour cells.	nitric oxide (no) is the major cytotoxic molecule produced by activated macrophages for cytotoxicity against entamoeba histolytica trophozoites. in the present study, we determined whether e. histolytica infection and soluble amoebic proteins affected macrophage cytotoxicity against amoebae and tumour cells by modulating the inducible no synthase gene (inos) and no (measured as nitrite, no2-) and tumour necrosis factor-alpha (tnf-alpha) production. amoebic liver abscess-derived macrophages [days ...	1994	7533135
[prevalence of infection by intestinal helminths and protozoa in school children from a coastal locality in the province of valdivia, chile].	during july-august 1989, 219 coprological samples from primary school children from niebla and los molinos localities (39 degrees 52's, 73 degrees 26'w) in the coast of province of valdivia, chile, were analysed. prevalence % (in parentheses) of infection by intestinal protozoa and helminths were the followings: entamoeba histolytica: (18.0), entamoeba coli (34.0), endolimax nana (34.4), iodamoeba buetschlii (7.4), blastocystis hominis (64.3), giardia intestinalis (27.9) chilomastix mesnili (0.8 ...	1994	7654292
metastasis of entamoeba histolytica compared to colon cancer: one more step in invasion.	the multistep invasion process of metastasis is a well-conserved mechanism of normal symbiosis and pathogenic parasitosis. to illustrate this statement, we have compared cellular and molecular aspects of metastasis from colon cancer and enteric amebiasis caused by entamoeba histolytica. both types of pathogenic cell, cancer cells and amebic trophozoites, follow the same metastatic route for the liver and other organs. both establish invasion microecosystems implicating similar kinds of host cell ...	1994	7657511
[amebic liver abscess: review of 9 cases].	amoebiasis is an infection of the large intestine produced by the protozoan entamoeba histolytica. more than 10% of the world population is estimated to be infected. the italian pattern of this infection is similar to the eec trend: the prevalence is approximately 0.012% during the years '88 and '89. hepatic abscesses usually present with moderate fever, weight loss and abdominal pain. during the last ten years nine patients with amoebic liver abscesses were admitted to our hospital, six males a ...	1994	7761679
intestinal parasitic infections and swamp development in sierra leone.	the prevalence of entamoeba histolytica, giardia lamblia and other intestinal and urogenital parasites were assessed in five inland valley swamp (ivs) development faming communities in the moyamba district, south-central sierra leone. stool and urine samples were submitted by 1106 individuals and examined by the iron-haematoxylin staining and the formalin-ether concentration techniques for faecal sample and centrifugation method for the urine samples. the overall parasitic infection rate was 61. ...	1994	12153344
cardiac tamponade secondary to intrapericardial rupture of a hepatic amoebic abscess.	we report the case of a patient who underwent an emergency subxiphoid pericardiectomy with evacuation of 1700 cc of anchovy sauce-like fluid. on pericardial inspection a fistulous communication was seen with a cavity in the left hepatic lobe. no loculi or adhesions were found in the pericardial sac and no further surgical procedure was advised. the hepatic cavity and pericardium were drained: bacteriological investigation of the fluid yielded entamoeba histolytica and chloroquine was administere ...	1994	8172716
cysteine endopeptidases of entamoeba histolytica.		1994	7845229
acid sphingomyelinase possesses a domain homologous to its activator proteins: saposins b and d.	an n-terminal region of the acid sphingomyelinase sequence (residues 89-165) is shown to be homologous to saposin-type sequences. by analogy with the known functions of saposins, this sphingomyelinase saposin-type domain may possess lipid-binding and/or sphingomyelinase-activator properties. this finding may prove to be important in the understanding of niemann-pick disease, which results from sphingomyelinase deficiency.	1994	8003971
amebic abscess of the spleen complicated by metronidazole-induced neurotoxicity: case report.	we describe a patient with a liver abscess due to entamoeba histolytica, in whom metronidazole therapy (total dose, 21 g over 14 days) was complicated by reversible deafness, tinnitus, and ataxia and who relapsed 5 months later with a splenic abscess. two courses of tinidazole (the second in combination with percutaneous aspiration of the abscess) were required to achieve cure.	1994	7986915
prevalence of intestinal parasites in rural areas of district shahjahanpur, uttar pradesh.	a stool survey was carried out in some of the villages of dadraul and bhawal khera phc's of district shahjahanpur (uttar pradesh). out of 381 individuals examined 111 (29.2 per cent) were found positive for one or the other intestinal parasite. ascaris lumbricoides superseded all the parasites by showing a positivity of 17.85 percent. other parasites found were hookworm, hymenolepis nana, tapeworm, trichuris trichiura, enterobius vermicularis, entamoeba histolytica, e. coli and giardia lamblia. ...	1994	7989672
detection of immune complexes in tissues of persons infected with entamoeba histolytica.	immune complexes were detected by radioimmunoassay in colonic tissue from 71 to 122 patients (58%) excreting entamoeba histolytica cysts and in liver tissue from 5 of 16 of these patients. complexes were also found in colonic tissue from 9 of 56 other patients (16%) who were not excreting cysts.	1994	7992334
a beta 1 integrin-like molecule in entamoeba histolytica.	human invasive amoebiasis is highly destructive, causing rapid necrosis and liquefaction of all tissues reached by the trophozoites. degradation of extracellular matrix components (emc) has been demonstrated during invasion of the basal lamina. pursuing the idea that trophozoites might behave similarly to other invasive cells with respect to their interaction with emc, plasma membrane proteins biochemically or functionally related to integrins were looked for. a 140 kda molecular mass membrane p ...	1994	7992351
nucleotide sequence organisation and analysis of the nuclear ribosomal dna circle of the protozoan parasite entamoeba histolytica.	we have sequenced the extrachromsomal ribosomal dna (rdna) circle of the human protozoan parasite entamoeba histolytica hm-1:imss and present here the complete sequence organisation of the 24.5-kb molecule. each circle contains two 5.9-kb rdna transcription units organised as inverted repeats. the regions downstream (3543 bp) and upstream (9216 bp) of the rdnas contain various families of short tandem repeats. some of the upstream repeats share extensive sequence homology with the downstream rep ...	1994	7870125
induction of the iron-containing superoxide dismutase in entamoeba histolytica by a superoxide anion-generating system or by iron chelation.	the regulation of superoxide dismutase (sod) expression was studied in 4 entamoeba histolytica isolates. in comparison to anaerobic conditions, cultivation of the amoebae in the presence of superoxide radical anions or a ferrous iron chelator revealed substantial increase of sod expression. under the different culture conditions, all sod activity could be exclusively attributed to an iron-containing type (fesod). northern blot analysis revealed that fesod expression was regulated on the transcri ...	1994	7870132
[necrotizing amebic colitis].	we report a case of necrotizing amebic colitis in a 43 year-old patient, 10 years after a stay in senegal, successfully treated by right hemicolectomy. entamoeba histolytica were found in colon necrosis and amoebiasis serology was positive, leading to the diagnosis. the epidemiologic, physiopathologic, clinical and therapeutic features of this exceptional affection are described. a few cases have been previously reported in non endemic areas where pre-operative diagnosis is rarely made. in endem ...	1994	7875425
purification and immunologic characterization of a 30-kda cysteine proteinase of entamoeba histolytica.	a 30-kda cysteine proteinase was purified from extracts of axenically grown trophozoites of entamoeba histolytica strain hm1:imss. the purification procedure involved two consecutive chromatographic steps. sequence analysis revealed high similarity with histolysin and with other 27-kda cysteine proteinase. western-blot analysis using f(ab')2 fragments of a polyclonal antibody raised against the purified enzyme revealed that when the amebic extract was prepared in the absence of proteinase inhibi ...	1994	7855127
encysted ascites caused by entamoeba histolytica.		1994	7860489
serodiagnostic evaluation of amoebic hepatitis.		1994	7860573
effect of histamine and glucose on encystation of entamoeba histolytica in vitro.	isolates of entamoeba histolytica grown and maintained in modified boeck and drbohlav's medium were used to examine the effect of histamine and glucose on encystation process in vitro. this revealed that 60-74% of the active and motile trophozoites of e. histolytica encysted within 72 hours in the presence of histamine and glucose, in contrast to 10-20% encystment in controls (with out histamine and glucose); a highly significant difference (p < 0.001). these observations also suggest the possib ...	1994	7863552
[entamoeba histolytica (schaudinn 1903) and entamoeba dispar (e. brumpt 1925) are 2 different species].	on the basis of epidemiologic and clinical data in humans, and of experimental studies in kittens, e. brumpt in 1925 showed that entamoeba histolytica producing quadrinucleate cysts was a complex of 2 species. he differentiated a pathogenic and invasive form, from a non pathogenic and non invasive one that he called entamoeba dispar. his explanation gained little support until recently, when sargeaunt reported a study of isoenzyme typing and allow then the classification of amoebae resembling e. ...	1994	7866041
exercise-induced diarrhea: when to wonder.	exercise-associated lower gastrointestinal symptoms seem to be a fairly common clinical finding occurring in anywhere from 10-50% of runners. however, it is unclear what percentage of those affected may have discrete medical conditions that are exacerbated by strenuous physical exertion. perhaps, difficult physical training sessions function as a "stress test" for the colon. a case report of exercise induced diarrhea is presented with a discussion of the current medical literature and proposed m ...	1994	8007797
[an analysis of the antigenic structure of the membrane complex in leishmania].		1994	8015520
symptomatic amebic colitis in a japanese homosexual aids patient.	a 30-year-old japanese homosexual aids patient was admitted to hospital because of kaposi's sarcoma and mild diarrhea on february 4, 1993. mud-like stool with blood and mucous was recognized after admission. although serologic tests for entamoeba histolytica were negative, trophozoites of e. histolytica were identified in his bloody stool. daily doses of 1,000 mg of metronidazole were given orally for 6 days and then 750 mg for 4 days, and good results were observed. his cd4 count was 19.5/mm3. ...	1994	8019042
isolation and characterization of a species-specific multicopy dna sequence from entamoeba histolytica.	a genomic library of entamoeba histolytica (pathogenic strain hm-1:imss) was screened to detect repetitive dna clones other than those from the highly abundant ribosomal dna (rdna). one such clone (hmc) had a 2.3 kb insert which hybridized with the main genome and not the rdna circle. southern hybridization of e. histolytica genomic dna, digested with ecor i and probed with hmc, showed multiple bands. the banding pattern was identical in all axenic pathogenic strains tested. differences, however ...	1994	8022651
intestinal parasitism in the united states: update on a continuing problem.	to document patterns of intestinal parasitism in the united states, we analyzed results of 216,275 stool specimens examined by the state diagnostic laboratories in 1987; parasites were found in 20.0%. percentages were highest for protozoans: giardia lamblia (7.2%), entamoeba coli and endolimax nana (4.2% each), blastocystis hominis (2.6%), and entamoeba histolytica (0.9%). the most commonly identified helminths were nematodes: hookworm (1.5%), trichuris trichiura (1.2%), and ascaris lumbricoides ...	1994	8024063
antiparasitic activity of diallyl trisulfide (dasuansu) on human and animal pathogenic protozoa (trypanosoma sp., entamoeba histolytica and giardia lamblia) in vitro.	garlic (allium sativum l.) and one of its major components, allicin, have been known to have antibacterial and antifungal activity for a long time. diallyl trisulfide is a chemically stable final transformation product of allicin which was synthesized in 1981 in china and used for treatment of bacterial, fungal and parasitic infections in man. the activity of diallyl trisulfide was investigated in several important protozoan parasites in vitro. the ic50 (concentration which inhibits metabolism o ...	1994	8024350
diagnosis of amebic dysentery by detection of entamoeba histolytica fecal antigen by an invasive strain-specific, monoclonal antibody-based enzyme-linked immunosorbent assay.	an invasive strain-specific monoclonal antibody against entamoeba histolytica has been used in a capture enzyme-linked immunosorbent assay (elisa) for the detection of invasive e. histolytica fecal antigen in clinical specimens and for the diagnosis of amebic dysentery in patients from bangladesh. the fecal antigen capture elisa (fac-elisa) did not cross-react with other parasite species in the clinical specimens or with noninvasive e. histolytica present in those specimens and in experimentally ...	1994	8027351
invasive amoebiasis is associated with the development of anti-neutrophil cytoplasmic antibody.	features of tissue damage in invasive amoebiasis, in particular polymorphonuclear neutrophil (pmn) degranulation and vasculitis, bear resemblance to that seen in wegener's granulomatosis, the latter being associated with the presence of anti-neutrophil cytoplasmic antibodies (anca). we therefore tested sera from patients with confirmed amoebic liver abscess (ala) for the presence of anca by means of an indirect fluorescent antibody test using pure neutrophils as substrate. anca was detected in 9 ...	1994	8033420
entamoeba histolytica and e. dispar.		1994	8036693
adherence and cytotoxicity of entamoeba histolytica or how lectins let parasites stick around.		1994	8039871
cloning of entamoeba genes encoding proteolipids of putative vacuolar proton-translocating atpases.	molecular cloning techniques were used to identify genes encoding the proteolipids of putative vacuolar proton-transporting atpases (v-atpases; ec 3.6.1.35) of entamoeba histolytica (ehvma3) and entamoeba dispar. the ehvma3 gene encoded a 177-amino-acid peptide, with an m(r) of 18,110, which showed extensive positional identities with peptides of e. dispar (92%), schizosaccharomyces pombe (58%), and humans (56%).	1994	8039932
transfection and transient expression of chloramphenicol acetyltransferase gene in the protozoan parasite entamoeba histolytica.	hybrid plasmids were constructed and used for successful transfection and transient expression of the chloramphenicol acetyltransferase (cat) gene in the protozoan parasite entamoeba histolytica. transfection was performed by electroporation of the amebae in a potassium phosphate-based buffer under conditions of 3000 v/cm and 25 microf, resulting in a time constant of 0.4 ms. expression of cat activity was achieved with constructs in which the cat coding region was flanked by untranslated upstre ...	1994	8041751
transient transfection of the enteric parasite entamoeba histolytica and expression of firefly luciferase.	development of dna-mediated transfection in entamoeba histolytica will facilitate basic research toward the control of this protozoan parasite. a transient transfection system was established by using the firefly luciferase gene ligated to the 5' and 3' flanking regions of the amebic hgl1 gene. the optimal construct tested encoded an hgl1-luciferase fusion protein and contained 1 kb of 5' flanking sequence with 16 bases of coding sequence from the hgl1 gene ligated in-frame to the luciferase sta ...	1994	8041752
[epidemiologic setting of the agricultural use of sewage: valle del mezquital, mexico].	wastewater from mexico city is used to irrigate over 85,000 hectares mainly of fodder and cereal crops in the mezquital valley. a cross-sectional study method is being used to test the impact of exposure to raw wastewater and wastewater from storage reservoirs on diarrheal disease and parasitic infections in farmworkers and their families. the study population in the rainy season survey included 1,900 households: 680 households where the farmworker is exposed to untreated wastewater (exposed gro ...	1994	8042068
characterization of monoclonal antibodies to conserved antigens of entamoeba histolytica and e. dispar and development of a stool elisa.	eight murine monoclonal antibodies (mabs) were generated against entamoeba histolytica nih:200. all mabs reacted with three axenic strains of e. histolytica, nih:200, hm-1: imms, and saw 1734r clar, but not with enteric bacteria or giardia lamblia. five of the mabs reacted with low-molecular-weight, periodate-sensitive antigens of 14-21 kd, while one (ab31) reacted with high-molecular-weight, 90 to 200-kd protein determinants. mab pc14 appeared to be specific for antigen in its native state. ano ...	1994	8050777
detection of cryptosporidium and giardia intestinalis in bedouin children from southern israel.	during an 18 month period, a total of 4796 stool specimens collected from 151 bedouin children enrolled in a cohort study and followed from birth, were screened for giardia intestinalis, cryptosporidium spp. and other intestinal parasites. specimens were collected in phenol-alcohol-formalin (paf) preservative and examined prior to, and after, formalin-ether concentration (fec). during 6 months of the second year giardia intestinalis was observed in 17.6% of the specimens and cryptosporidium in 0 ...	1994	8070959
antibodies to the serine rich entamoeba histolytica protein (srehp) prevent amoebic liver abscess in severe combined immunodeficient (scid) mice.	amoebic liver abscess caused by entamoeba histolytica is a major cause of morbidity and mortality worldwide. we used mice with severe combined immunodeficiency (scid mice) to study the role of antibody in protection from amoebic liver abscess, and to identify protective antigens of e. histolytica. antisera to recombinant versions of two major surface antigens of e. histolytica, the serine rich e. histolytica protein (srehp) and the 170 kda adhesin were used in this study. we found that 100% of s ...	1994	8072766
[bacterial dysentery in 1992].		1994	8073150
phylogenetic place of a mitochondria-lacking protozoan, entamoeba histolytica, inferred from amino acid sequences of elongation factor 2'.	partial dna regions encoding a major part of translation elongation factor 2 (ef-2) from a mitochondria-lacking protozoan, entamoeba histolytica, were amplified by polymerase chain reaction and their primary structures were analyzed. the deduced amino acid sequence was aligned with other eukaryotic and archaebacterial ef-2's, and the phylogenetic relationships among eukaryotes were inferred by the maximum likelihood (ml) method. the ml analyses using four different stochastic models of amino aci ...	1994	8074887
socio-economic factors associated with intestinal parasites among children living in gombak, malaysia.	fecal specimens collected from 456 school children in gombak, malaysia, revealed an overall prevalence rate of 62.9%. the most common parasite found was trichuris trichiura (47.1%) followed by giardia intestinalis (14.7%), entamoeba coli (11.4%), entamoeba histolytica (9.9%) and ascaris lumbricoides (7.9%). infection rates were high among the indonesian immigrant workers' children (90%) followed by the orang asli (79.5%), malay (59.4%) and indians (36.4%). females (66.3%) had a higher prevalence ...	1994	8074940
cloning, genomic organization and transcription of the entamoeba histolytica alpha-tubulin-encoding gene.	we have isolated and characterized an entamoeba histolytica alpha-tubulin (alpha tub)-encoding gene (eh alpha tub). a 700-bp dna fragment was amplified by pcr using primers derived from consensus alpha- and beta-tub amino acid (aa) sequences from different organisms and e. histolytica dna as the template. these pcr fragments were used to screen both genomic dna and cdna libraries in order to isolate an eh alpha tub structural gene. two overlapping clones containing the complete alpha tub orf (13 ...	1994	8076825
two-year study of endemic enteric pathogens associated with acute diarrhea in new caledonia.	a longitudinal study of diarrheal disease among patients of all ages with acute diarrhea was carried out in new caledonia from january 1990 to december 1991. stool samples from 2,088 diarrheal patients were examined for parasites, rotavirus, and bacterial pathogens. potential sources of contamination (drinking water, seawater and bovine and porcine feces) were investigated. one or more enteric pathogens were identified in 41.8 and 40.6% of the persons with diarrhea, in 1990 and 1991, respectivel ...	1994	8077399
molecular cloning of ras and rap genes from entamoeba histolytica.	to better understand growth regulation in the protozoan parasite entamoeba histolytica, ameba genes homologous to the ras oncogene and rap (krev-1) anti-oncogene were cloned. two putative ameba ras genes (ehras1 and ehras2) were identified, which contain 205 and 203 amino acid (aa) open reading frames (orfs), respectively. the ehras1 orf shows an 91% positional identity with that of ehras2, a 55% identity with dictyostelium discoideum (dd) ras, and a 47% identity with human (hs) ras. two ameba r ...	1994	8078515
identification of a putative pore-forming hemolysin active at acid ph in leishmania amazonensis.	several organisms, including the protozoa entamoeba histolytica and trypanosoma cruzi, have been shown to contain pore-forming proteins (pfp) thought to play a role in the pathogenesis of the diseases they generate. in the present report, we show that promastigotes of leishmania amazonensis express a hemolysin that appears to cause colloid-osmotic lysis, typical of pore formation. this hemolysin affects red blood cells of different species at 37 degrees c, but not at 0 degrees c, with maximum ac ...	1994	8081268
rapid latex agglutination test for extraluminal amoebiasis.	to develop a rapid latex agglutination screening test for invasive amoebiasis.	1994	8089223
protein phylogeny gives a robust estimation for early divergences of eukaryotes: phylogenetic place of a mitochondria-lacking protozoan, giardia lamblia.	a partial nucleotide sequence of the mrna encoding a major part of elongation factor 1 alpha (ef1 alpha) from a mitochondria-lacking protozoan, giardia lamblia, was reported, and the phylogenetic relationship among lower eukaryotes was inferred by the maximum-likelihood and maximum-parsimony methods of protein phylogeny. both the methods consistently demonstrated that, g. lamblia among the four protozoan species being analyzed, is the earliest offshoot of the eukaryotic tree. although the giardi ...	1994	8121287
amoebic brain abscess: a rare but serious complication of entamoeba histolytica infection.		1994	8126521
coding of hemolysins within the ribosomal rna repeat on a plasmid in entamoeba histolytica.	the pathogenesis of amoebic dysentery is a result of cytolysis of the colonic mucosa by the parasitic protozoan entamoeba histolytica. the cytolysis results in extensive local ulceration and allows the amoeba to penetrate and metastasize to distant sites. factors involved in this process were defined with three clones that express hemolytic activities in escherichia coli. these potential amoebic virulence determinants were also toxic to human colonic epithelial cells, the primary cellular target ...	1994	8128227
aids and the gut.	there are increasing challenges for the practising gastroenterologist in treating aids-related gastrointestinal diseases. the differential diagnoses of dysphagia and odynophagia include cytomegalovirus (cmv) and herpes simplex virus (hsv) infection, non-specific aphthous ulceration and non-aids oesophageal diseases, especially reflux oesophagitis. chronic subacute abdominal pain with nausea, vomiting, early satiety and weight loss is suggestive of an obstructive lesion caused by lymphoma or kapo ...	1994	8054532
direct amplification and differentiation of pathogenic and nonpathogenic entamoeba histolytica dna from stool specimens.	discrimination of pathogenic and nonpathogenic entamoeba histolytica is of great clinical importance. a simple and rapid dna extraction method that can be used directly with stool specimens was developed without the need for prior cultivation of the parasites. the entire protocol can be performed at room temperature in a 1.5-ml microcentrifuge tube format. there is no dna precipitation step. the subsequent nested polymerase chain reaction consists of an initial e. histolytica-specific amplificat ...	1994	8059910
protection of gerbils from amebic liver abscess by immunization with a recombinant entamoeba histolytica antigen.	amebiasis, infection by the intestinal protozoan parasite entamoeba histolytica, is a leading parasitic cause of death. as a step in the development of a recombinant antigen vaccine to prevent e. histolytica infection, we looked at the ability of a recombinant version of the serine-rich e. histolytica protein (srehp) to elicit a protective immune response against invasive amebic disease. gerbils, a standard model for amebic liver abscess, were immunized with either a recombinant srehp/maltose-bi ...	1994	8132322
in vitro antiplasmodial, antiamoebic, and cytotoxic activities of a series of bisbenzylisoquinoline alkaloids.	twenty-four bisbenzylisoquinoline alkaloids were screened for antiplasmoidal, antiamoebic, and cytotoxic activities by use of in vitro microtests. eight of the alkaloids had antiplasmodial activity, with a 50% inhibitory concentration (ic50) of less than 1 microm against a multidrug-resistant strain of plasmodium falciparum (chloroquine had an ic50 of 0.2 microm). the three alkaloids most active against entamoeba histolytica, aromoline, isotrilobine, and insularine, had ic50s of 5 to 11.1 microm ...	1994	8141587
cytolytic and antibacterial activity of synthetic peptides derived from amoebapore, the pore-forming peptide of entamoeba histolytica.	the pore-forming peptide amoebapore is considered part of the cytolytic armament of pathogenic entamoeba histolytica. amoebapore is composed of 77 amino acid residues arranged in four alpha-helical domains. for structure-function analysis, synthetic peptides were constructed corresponding to these four domains: h1 (residues 1-22), h2 (25-39), h3 (40-64), and h4 (67-77). the peptides h1 and h3, representing two highly amphipathic alpha-helical regions of amoebapore, possessed pore-forming activit ...	1994	8146160
inhibitory activity of saccharomyces yeasts on the adhesion of entamoeba histolytica trophozoites to human erythrocytes in vitro.	adhesion to target cells represents the first step in infection by entamoeba histolytica. binding of axenic amoeba (hmi strain) to human red cells in vitro was employed as a model of the adhesion process. the influence of precontact of trophozoites with suspensions of live saccharomyces boulardii yeasts, their fractions (membranes and yeast-content supernatant before and after filtration to eliminate the membrane) or yeast culture medium before and after fermentation was investigated. n-acetylga ...	1994	8153119
chemotherapy of entamoeba histolytica: studies in vitro with bacitracin and its zinc salt.	twenty-one entamoeba histolytica isolates from a range of geographical locations and representing 3 different zymodemes were tested under xenic anaerobic conditions for their sensitivities to bacitracin and bactracin zinc. isolates were over 13 times more sensitive to bacitracin zinc than to bacitracin. our results indicate that bacitracin zinc may form the basis of an alternative non-toxic treatment of luminal amoebiasis.	1994	8154020
value of microscopy in the diagnosis of dysentery associated with invasive entamoeba histolytica.	to assess the reliability of the detection of erythrophagocytic amoebic trophozoites in stool samples in the diagnosis of dysentery associated with invasive entamoeba histolytica.	1994	8163695
seroepidemiology of amebiasis in mexico.	the presence of serum antibodies to entamoeba histolytica was detected by indirect hemagglutination in a representative sample of the 32 federal entities of the mexican republic. this study was designed to include biologic, geographic, social, economic, and educational variables. the total percentage of positive sera was 8.41%. seroprevalence varied with geographic zones, with the south central, south pacific, and yucatan peninsula areas showing the highest values (> or = 9%), and the north, nor ...	1994	8166347
[second report on intestinal parasites among the patients of seoul paik hospital (1984-1992)].	the results of fecal examination for helminth eggs and protozoan cysts in seoul paik hospital during 1984-1992 are reported. fecal specimens of a total of 52,552 out- or inpatients were examined by formalin-ether sedimentation and/or direct smear method. the overall egg positive rate of helminths was 6.5% and the cyst positive rate of protozoa 2.5%. the egg positive rate (number of positive cases) for each species of helminth was; clonorchis sinensis 3.2% (1,667), trichuris trichiura 2.0% (1,089 ...	1994	8167105
bile salts help entamoeba histolytica to evade from immune attack.		1994	7896326
host-parasite relationships in amebiasis: conference report.	entamoeba histolytica has been redescribed as the separate species e. histolytica and entamoeba dispar. e. dispar is apparently never invasive in humans, while e. histolytica is the etiologic agent of amebic colitis and liver abscess. virulence factors that may enable e. histolytica to invade include a galactose-specific adhesin, secreted proteases, extracellular matrix receptors, and a cell surface lipophosphoglycan. progress in vaccine development includes the identification of the cysteine-ri ...	1994	7908923
brain abscess due to infection with entamoeba histolytica.	we successfully treated a serious case of entamoeba histolytica infection showing brain abscess, meningitis, and liver abscess by oral administration of metronidazole, intramuscular injection of dehydroemetine, and drainage of the brain abscess. the diagnosis of amebic brain abscess was based on a combination of clinical symptoms and signs, computed tomography and magnetic resonance imaging findings, a positive serologic test result for e. histolytica, a dramatic response to anti-amebic drugs af ...	1994	7915500
the use of an elispot assay to evaluate intestinal and systemic antibody responses to locally administered entamoeba histolytica antigen in mice.	the local induction of humoral immune response to entamoeba histolytica trophozoites in the gut has not been studied. this work reports some of our recent studies aimed to induce optimal immune responses against e. histolytica in mice and to describe a novel approach for monitoring mucosal immune responses induced in the gastrointestinal tract and expressed locally and systemically. we have compared the kinetics of both mucosal and systemic primary antibody responses to e. histolytica in the pey ...	1994	7919810
proteins of entamoeba histolytica trophozoites involved in the adhesion to target cells.	to identify the molecules involved in the adhesion of entamoeba histolytica trophozoites to target cells we used monoclonal antibodies (mabs) and adhesion-deficient mutants. human red blood cells (rbcs) were also used as specific carriers to identify the ameba molecules with affinity to the target cell receptors. mabs adh-1 and adh-2 inhibited adhesion of rbcs to the trophozoites and recognized a 112-kda surface protein that was present in the wild type strain, but was absent or modified in adhe ...	1994	7919814
a monoclonal antibody specific for a 40 kda polypeptide recognizes pathogenic strains of entamoeba histolytica.	in vitro interaction of entamoeba histolytica trophozoites with collagen induces the intracellular formation and release of electron-dense granules (edgs). we determined that four polypeptides in edgs total antigen by sds-page were absent in trophozoite extracts. a monoclonal antibody raised against these edgs recognized a polypeptide of 40 kda specific for the pathogenic strains of e. histolytica. in addition, this mab recognized a 96 kda peptide masked by carbohydrates.	1994	7919818
diagnosis of invasive amoebiasis--time to end the morphology era.		1994	7926897
leucocyte migration inhibition index responses of patients of amoebic liver abscess to various antigens of entamoeba histolytica.	the whole amoebic lysate (wal), sephadex g-200 eluted fraction-i. (f-i), detergent dissected membrane proteins (ddmp), amoebic membrane glycoprotein (amg) and amoebal rna were extracted from e. histolytica. amoebal rna recognized 98.21% where as f-i, amg, ddmp and wal recognised 92.85, 91.07, 89.28 and 75% of total 56 clinically proven and amoebic serology positive amoebic liver abscess cases respectively. intensity of recognition of individual fraction i.e., leucocyte migration inhibition index ...	1994	7927532
entamoeba histolytica interactions with polarized human intestinal caco-2 epithelial cells.	to model the initial pathogenic effects of entamoeba histolytica trophozoites on intestinal epithelial cells, the interactions of e. histolytica hm1-imss trophozoites with polarized human intestinal caco-2 cell monolayers grown on permeabilized filters were examined. trophozoites, when incubated with the apical surface of the monolayers at 37 degrees c, induced a rapid decrease in transepithelial resistance over 15 to 60 min. the transmonolayer resistance response was not associated with changes ...	1994	7927794
heterogeneity of the ribosomal dna episome in strains and species of entamoeba.	ribosomal dna sequences in several species of the genus entamoeba are highly repeated and display restriction fragment-length polymorphism (rflp), which has been used to identify species and differentiate strains. however, the continuous variability of the non-transcribed repeat sequences in the ribosomal episome hinders an accurate typification. looking for more reliable markers, we used dna probes containing conserved sequences in the ribosomal episome--coding regions for the 16s and 5.8s rrna ...	1994	7934884
entamoeba histolytica has an alcohol dehydrogenase homologous to the multifunctional adhe gene product of escherichia coli.	entamoeba histolytica ferments glucose to ethanol under the anaerobic conditions of the human colon. there is special interest in this metabolic pathway because it provides an opportunity for parasite-specific chemotherapy. peptide sequences from a 97-kda e. histolytica protein, which was originally isolated because of extracellular matrix binding properties, were used to clone and sequence a gene that was found to encode an e. histolytica alcohol dehydrogenase and acetaldehyde dehydrogenase (eh ...	1994	7935603
myo-inositol trisphosphate-mediated calcium release from internal stores of entamoeba histolytica.	calcium mobilisation from internal stores of the parasitic protozoan entamoeba histolytica was studied by fluorescence measurements of the calcium indicator quin 2 and 45ca2+ incorporation studies in saponin-permeabilised amoebae. prior energy-dependent calcium sequestration was found to be necessary for subsequent release of calcium by inositol 1,4,5-trisphosphate (ins(1,4,5)p3). both ins(1,4,5)p3 and inositol 2,4,5-trisphosphate (ins(2,4,5)p3) could release calcium equally well from permeabili ...	1994	7935629
[amoebiasis--a problem in patients with ulcerative colitis].	the increasing problem is presented of entamoeba histolytica invasion in patients with ulcerative colitis. the diagnostic-therapeutic management in five patients with amoebiasis is discussed in detail. this parasitic invasion occurred in five out of 103 patients with ulcerative colitis which accounts for 4.85%. this data is important for the treatment of chronically ill patients with ulcerative colitis.	1994	7941573
the sensitivity of axenic 200:nih entamoeba histolytica to bacitracin and its zinc salt.	this study extends the previous knowledge of the action of bacitracin zinc against xenic cultures of entamoeba histolytica. results presented here, using axenic e. histolytica, confirm the enhanced activity of bacitracin zinc as compared to native bacitracin and demonstrate that this enhancement is due to a direct effect upon the trophozoite. in the presence of zinc, amoebastatic concentrations of bacitracin became amoebacidal. the expression of the amoebacidal characteristics of 5 g/l bacitraci ...	1994	7942350
secretory immunoglobulin a antibodies to the galactose-inhibitable adherence protein in the saliva of patients with amebic liver disease.	monoclonal antibodies directed against the 260-kd galactose-inhibitable adherence protein (giap) of entamoeba histolytica inhibit binding of amebic trophozoites to purified colonic mucins, suggesting that anti-giap secretory immunoglobulin a (siga) may have a role in host defense in invasive amebiasis. we determined by enzyme-linked immunosorbent assay (elisa) whether a salivary anti-giap siga response was present in patients from the republic of south africa with invasive e. histolytica infecti ...	1994	7943572
cyclospora infection in adults infected with hiv. clinical manifestations, treatment, and prophylaxis.	to determine the prevalence and clinical manifestations of cyclospora in haitians infected with human immunodeficiency virus (hiv) who have diarrhea and to evaluate therapy and prophylaxis.	1994	7944073
antibacterial activity of metal complexes of benzil and benzoin thiosemicarbazones.	the metal (ii) complexes of benzyl and benzoin thiosemicarbazones have been synthesized and characterized. they were studied for their antibacterial, antifungal and amoebicidal activity in vitro and for their toxicity in vivo. the ligands and their metal complexes exhibited low antibacterial and amoebicidal activity. the metal chelates of benzoin thiosemicarbazone seem to be the most active compounds.	1994	7945719
amebiasis: human infection with entamoeba histolytica.		1994	7948936
[effects of monoclonal antibodies on phagocytosis of entamoeba histolytica to human erythrocytes].	two monoclonal antibodies 3f7 and 4g6 were produced respectively against plasma membrane and nucleus-cytoplasm of entamoeba histolytica. the erythrocytophagous quantification and ability of pathogenic strain hm-1:imss were evaluated by microscopy immediately at 5 min and 10 min after incubation with mcab 3f7 and mcab 4g6. sera from normal mice and monoclonal antibody tce 04 against trypanosoma cruzi were prepared as negative controls. the mcab 3f7 showed stronger inhibitory action on the erythro ...	1994	7955164
entamoeba histolytica: mechanism of surface receptor capping.	binding of antibodies to the surface of the parasitic protozoan entamoeba histolytica induces capping and release of antigen-antibody complexes, in a process that may be an effective means of evading the host immune response. to analyze the mechanism of capping in e. histolytica trophozoites, optimal conditions were determined for cap induction by sera from patients with amebic liver abscess, by polyclonal anti-amebic antibodies, and by concanavalin a. cocapping of actin and myosin was documente ...	1994	7957761
entamoeba histolytica: pkc transduction pathway activation in the trophozoite-fibronectin interaction.	interaction of entamoeba histolytica trophozoites with fibronectin (fn) induces reorganization of the actin cytoskeleton and an increase in proteolytic activities that results in the degradation of the bound protein. the binding is mediated by a 37-kda fn "receptor" localized in the trophozoite surface and associated to the cytoskeleton. the intracellular signals triggered by the ligand-receptor interaction are not well understood but it is plausible that they drive the observed responses. to ad ...	1994	7957762