Publications

characterization and quantitation of parasite species in the effluents of the berisso main sewage channel, buenos aires, argentina.	outbreaks of disease can be caused by pathogenic intestinal parasites in drinking water. la plata, the capital of the province of buenos aires, argentina, is located on the la plata river; a principal tributary receiving the raw sewage from the city's 500,000 inhabitants via the berisso main septic channel at an estimated volume of 108,390 m3/day (4516.3m3/h). to determine the parasite-contamination level of the la plata river, we obtained 18 sewage effluents from the berisso main septic channel ...	1997	9638888
[vegetables for human consumption as probable source of toxocara sp. infection in man].	although toxocara canis life cycle is known, other possible mechanisms dynamically involved in its transmission to man are still ignored. the object of the present investigation was to search the occurrence of toxocara sp. eggs in vegetables which humans consume. five hundred and thirty six vegetables from a supply distribution center in mexico city (distrito federal) were examined. those included 212 carrots, 76 potatoes, 31 radishes, 22 mushrooms, 27 lettuces, 20 sweet potatoes and 66 bundles ...	1997	9640678
nitazoxanide for the treatment of intestinal protozoan and helminthic infections in mexico.	a study to evaluate the efficacy and safety of nitazoxanide as a single agent for the treatment of a broad spectrum of mixed parasitic infections, both protozoa and helminths, was conducted at a primary school in san pedro tolimán, querétaro, mexico. three faecal samples from 1824 adults and children were screened for the presence of oocysts, cysts, trophozoites, eggs or larvae of intestinal protozoa or helminths. two hundred and forty-six adults and children infected with at least one protozoan ...	1997	9580117
the bactericidal activity of blood platelets in patients infested with entamoeba histolytica/entamoeba dispar.	blood platelets participate actively in organism defensive reactions and particularity in antiparasitic immunity. platelets stimulation can be the result of contact with a parasite, the presence of immunoglobulins, complement and lymphokines. the aim of the study was to evaluate the blood platelets bactericidal activity in the course of amoebiasis. the examination was carried out in the group of 22 patients with e. histolytica/e. dispar, diagnosed on the basis of cyst forms presence in faeces. t ...	1997	9581473
[an amebic liver abscess; early suspicion, late detection].	two men aged 38 and 26 years developed symptoms including pain in the (upper) abdomen, malaise and fever 1.5-5 months after visiting the caribbean. it was only after repeated ultrasonography that liver abscesses were observed. adequate treatment was instituted and the patients recovered. the diagnosis of 'amoebic abscess of the liver' is usually based on the clinical presentation, the serological findings and characteristic observations at ultrasonography. however, if patients are seen at an ear ...	1997	9542869
[enteroparasitoses in food handlers of the public schools in uberlândia (minas gerais), brazil].	a prospective study based on a parasitologic survey was carried out with a view toward controlling enteroparasitoses in food handlers who work in public primary schools in uberlândia, minas gerais, brazil. the study subjects were 264 individuals from 57 schools, from whom three fecal samples (c) were collected: c1 in september 1989, c2 in april 1990, and c3 in september 1990. the participants were predominantly female (259 women and 5 men) and ranged in age from 20 to 66 years. a total of 792 sa ...	1997	9546081
heterogeneity of dna content and expression of cell cycle genes in axenically growing entamoeba histolytica hm1:imss clone a.	the cell division cycle of entamoeba histolytica was studied using multi-parametric flow cytometry in asynchronous and partially synchronised cells. dynamic changes in the dna synthesis and dna content of axenically growing trophozoites were observed by using 5-bromo-2'-deoxyuridine (brdu) uptake and dna specific fluorochromes. it was observed that dna synthesis in these cells continues beyond the typical s-phase stop point when dna duplication is complete. asynchronously growing e. histolytica ...	1997	9497028
molecular and biochemical characterization of phosphoglucomutases from entamoeba histolytica and entamoeba dispar.	entamoeba histolytica and entamoeba dispar have only recently been defined as two separate species. e. histolytica, the pathogenic species, is the microorganism causing invasive intestinal amoebiasis and/or liver abscess, while the morphologically similar e. dispar is nonpathogenic and noninvasive. the gold standard for the distinction of the two species has been the isoenzyme electrophoresis of phosphoglucomutases (ec 5.4.2.2) and hexokinases (ec 2.7.1.1), but there had also been a controversy ...	1997	9497037
primary structure of entamoeba histolytica gamma-tubulin and localisation of amoebic microtubule organising centres.		1997	9497056
[infection by intestinal protozoa and helminths in schoolchildren from riverside sectors, with different fecal contamination levels, of valdivia river, chile].	during 1993, the prevalences of infection by intestinal protozoa and helminths (iph) in the riverside schoolchildren population of two sectors of valdivia river, with different levels of fecal contamination, were compared in relation to their contact with river water (swimming, bathing) and basic sanitation elements (bse) of their houses: feces and garbage disposal, and water supply. populations of children from sectors a (n = 418), with significatively greater (sg) total coliform most probable ...	1997	9497533
[human infection by intestinal protozoa and helminths in calbuco county, x region, chile, 1997].	by the performance of parasitological examination of one fecal sample per individual, a total of 256 persons from a rural county in the x region (41 degrees 50 minutes south lat., 73 degrees 05 minutes west long.) were studied. the general rates of infection by intestinal parasite and/or commensal protozoa and helminths found were: giardia intestinalis 14.1%, entamoeba histolytica 11.7%, blastocystis hominis 36.0%, entamoeba coli 9.8%, endolimax nana 16.4%, iodamoeba buetschlii 1.2%, chilomastix ...	1997	9497539
liver involvement in systemic infection.	the liver is heavily involved in the vast majority of systemic infections. pathophysiological mechanisms involved in hepatic involvement in generalized sepsis require further study, as does the importance of bacterial infection in the presence of cirrhosis. although parasitic involvement is theoretically dominated by plasmodium spp., in clinical practice entamoeba histolytica, schistosoma spp. and echinococcus spp. infections are far more important. hepatobiliary involvement is also a feature of ...	1997	9471032
[epidemiology of children's intestinal parasitism in the guadalquivir valley, spain].	intestinal parasitism represents a public health problem that should be periodically assessed in each region. in the present paper, a study about prevalence of intestinal parasites, has been carried out in children from the natural region of the guadalquivir valley.	1997	9477709
pyogenic liver abscess in children: some observations in the espírito santo state, brazil.	pyogenic liver abscess in children is uncommon in developed countries and there are few reports about the disease in developing countries including brazil. as pyogenic liver abscesses in children are frequently diagnosed in vitória (e. santo state, brazil), the records of admissions at the children's hospital (hospital infantil n.s. da glória) were surveyed. sixty-five cases of pyogenic liver abscess were observed over a period of three years, from may 1991 through april 1994 (mean of admissions ...	1997	9458960
involvement of superoxide dismutase and pyruvate:ferredoxin oxidoreductase in mechanisms of metronidazole resistance in entamoeba histolytica.	metronidazole resistance has been induced in an axenic strain of entamoeba histolytica (hth-56:mutm) following continuous exposure to steadily increasing drug concentrations. the drug-resistant line is routinely maintained in normally lethal levels of metronidazole (10 microm). resistance to this concentration of drug was developed over 177 days. decreased pyruvate:ferredoxin oxidoreductase (pfor) activity in anaerobic organisms is one mechanism of metronidazole resistance but in entamoeba, pfor ...	1997	9462435
[the diagnosis and surgical treatment of intestinal amebiasis].	ninety-one patients with intestinal amebiasis (ia) were studied. all had been long suffering from ia due to the fact that it had not been diagnosed in time. indications for emergency surgery were profuse hemorrhage, perforation of amebic ulcers, gangrene, and toxic dilatation of the large intestine. planned operations were made in pseudopolyposis, strictures of the large intestine. surgical treatment was performed along with specific therapy. seven patients died due to late diagnosis, ineffectiv ...	1997	9446003
effect of bacterial association on the phenotype and genotype of an entamoeba histolytica clonal population.	a several-times-cloned population of entamoeba histolytica trophozoites (clone maviii) was cultured under axenic (maviiiax), monoxenic (maviiimx) and polyxenic (maviiipx) conditions. clones maviiiax and maviiimx presented similar virulence in vitro, but differed in their virulence in vivo, whereas maviiipx trophozoites were neither virulent in vitro or in vivo. the maviii clones maintained their zymodeme and exhibited three unusual glucose phosphate isomerase bands, absent in other e. histolytic ...	1997	9778590
does the eosinophil have a protective role in amebiasis?	while normal human eosinophils are destroyed in vitro by virulent entamoeba histolytica, notwithstanding the presence of antibodies and complement, activated eosinophils promptly destroy the parasite although dying also at the end of the process. to study the possible in vivo participation of eosinophils in invasive amebiasis, we compared the induction of experimental amebic abscess of the liver (aal) in gerbils (meriones unguiculatus) previously made eosinophilic through toxocara canis antigen ...	1997	9698942
bacterium-assisted invasion of entamoeba histolytica through human enteric epithelia in two-compartment chambers.	entamoeba histolytica trophozoites initiate amebiasis by invasion into the enteric mucosa. it is the aim of our experiments to understand how bacteria and leukocytes act during amebic invasion through enteric cell layers. cocultures were established in two-compartment chambers and studied by measurement of transepithelial electrical resistance (ter) and by histological examination. trophozoites caused a decrease in ter that was followed by formation of holes in the enteric cell layer and transfi ...	1997	9702940
glycosidases in mucin-dwelling protozoans.	a range of protozoans were tested for the presence of glycosidases using p-nitrophenyl sugars as substrates. some of the organisms were mucin dwellers whereas others were blood borne parasites. it had been hypothesized that glycosidase production would be significantly higher in the mucin dwellers. the results obtained demonstrated that the urogenital protozoans tritrichomonas foetus and trichomonas vaginalis produced a vast range of glycosidases which included those required for mucin breakdown ...	1997	9511996
parasites and diarrhea. i: protozoans and diarrhea.	intestinal parasitism is extremely common, with approximately 70% of all people harboring one or more intestinal parasite. parasitism and diarrhea are both hyperendemic in areas where sanitation is suboptimal. many clinicians assume that the identification of intestinal parasites in patients with diarrhea implies that the parasites are the cause. this approach is frequently misguided. some intestinal parasites such as giardia lamblia and entamoeba histolytica certainly do cause diarrhea. others, ...	1997	9815473
entamoeba histolytica and entamoeba dispar in the northeast brazil.		1997	9674291
phagocytes from both vertebrate and invertebrate species use "coiling" phagocytosis.	coiling phagocytosis has been observed previously only by chance, and there has been no systematic investigation of this uptake mechanism. therefore, a comparative electron microscopical study was performed. different human and murine cell populations, phagocytes from various vertebrate and invertebrate species, and predatory amoebae were incubated with borrelia burgdorferi, one of the microbes known to induce coiling phagocytosis, to study the uptake mechanisms used. in this model, coiling phag ...	1996	9040982
purification and characterization of the acetate forming enzyme, acetyl-coa synthetase (adp-forming) from the amitochondriate protist, giardia lamblia.	giardia lamblia, an amitochondriate eukaryote, contains acetyl-coa synthetase (adp-forming), an enzyme known only from one other eukaryote (entamoeba histolytica) and a few anaerobic prokaryotes. the enzyme has been purified about 350-fold. the activity in the direction of acetate formation was dependent on adp and inorganic phosphate. the reverse reaction could not be detected. succinyl-coa, propionyl-coa and dadp were utilized with lower efficiency. the enzyme did not utilize amp plus ppi thus ...	1996	8557109
oral immunization with an attenuated vaccine strain of salmonella typhimurium expressing the serine-rich entamoeba histolytica protein induces an antiamebic immune response and protects gerbils from amebic liver abscess.	attenuated salmonellae represent attractive candidates for the delivery of foreign antigens by oral vaccination. in this report, we describe the high-level expression of a recombinant fusion protein containing the serine-rich entamoeba histolytica protein (srehp), a protective antigen derived from virulent amebae, and a bacterially derived maltose-binding protein (mbp) in an attenuated strain of salmonella typhimurium. mice and gerbils immunized with s. typhimurium expressing srehp-mbp produced ...	1996	8613356
fibronectin-induced intracellular calcium rise in entamoeba histolytica trophozoites: effect on adhesion and the actin cytoskeleton.	the interaction of entamoeba histolytica trophozoites with fibronectin (fn) promotes adhesion of the protein to the cells and its later degradation by locally released proteases. binding to fn-covered surfaces induces, in addition, the formation of actin adhesion plates and focal contacts in the amebas. the signaling mechanisms underlying the response to fn are incompletely understood. in this paper we examined the modifications of cytosolic free calcium ([ca2+]i) induced in the trophozoites by ...	1996	8617326
entamoeba histolytica: isoprenylation of p21ras and p21rap in vitro.		1996	8617332
entamoeba histolytica: involvement of pp125fak in collagen-induced signal transduction.	the interaction of entamoeba histolytica trophozoites with collagen involves cell adherence, formation, and release of electron dense granules (edgs) containing collagenase activity leading to the degradation of the bound protein. the binding is thought to be mediated by an "integrin-like" collagen receptor. since the signal transduction mechanisms triggered by the collagen-trophozoite interaction are unknown, but clearly involve cytoskeletal organization, we decided to explore the role of prote ...	1996	8617343
entamoeba histolytica: localization of a 30-kda cysteine proteinase using a monoclonal antibody.	we produced a monoclonal antibody against a major cysteine proteinase of 30kda from trophozoites of entamoeba histolytica strain hm1:imss. the specificity of the monoclonal antibody was confirmed by specific inhibition of azocasein digestion and by electrophoretic analysis, in the presence of sodium dodecyl sulfate or on a substrate gel, of the antigen precipitated by the antibody. immunofluorescent staining of trophozoites with the monoclonal antibody revealed heterogeneity in the intensity of ...	1996	8617344
the effect of chronic intestinal parasitic infection on maternal and perinatal outcome.	the main objective of this prospective cohort study was to investigate the prevalence, risk factors and maternal-perinatal consequences of chronic asymptomatic intestinal parasitic infection during pregnancy.	1996	8620997
[a case of amoebiasis as a latent infection].	a 69-year-old male was admitted because of constipation and abdominal distension. a colon fiberscopic examination revealed the formation of ulceration. the trophozite of entamoeba histolytica was detected from from the specimens of colon mucosal biopsy of the ulcer. the stool was positive for the cysts of e. histolytica too. he had been in china and southeast asia during world war ii. he returned home and experienced amoebic dysentry, and was treated with emethin hydrochlolide. he suffered from ...	1996	8621966
prevalence of enteropathogens in stools of rural maasai children under five years of age in the maasailand region of the kenyan rift valley.	stool samples were collected during august 1994 from seventy rural maasai children under the age of five years who were living in the maasailand region of the kenyan rift valley. microbiological analysis was carried out on these samples to identify which intestinal pathogens were present among the infant population of the maasai. of the samples studied 54% were pathogen positive. the most common pathogen isolated was giardia lamblia which was detected in 31% of the samples. other pathogens that ...	1996	8625866
evidence for the existence of both proteasomes and a novel high molecular weight peptidase in entamoeba histolytica.	to screen for high molecular weight proteases in entamoeba histolytica, we subjected a soluble amebal extract to density gradient centrifugation and tested the fractions for activity against the chymotryptic peptide substrate, suc-leucyl-leucyl-valyl-tyrosyl-4-methylcoumaryl-7-amide. two peaks of activity, of approximately 11 and 20 s, were clearly separated. based on sds-electrophoretic pattern and immunoblot analysis, we ascribe the 20 s activity to proteasomes. the 11 s protein was purified f ...	1996	8626412
replication initiates at multiple dispersed sites in the ribosomal dna plasmid of the protozoan parasite entamoeba histolytica.	in the protozoan parasite entamoeba histolytica (which causes amoebiasis in humans), the rrna genes (rdna) in the nucleus are carried on an extrachromosomal circular plasmid. for strain hm-1:imss, the size of the rdna plasmid is 24.5 kb, and 200 copies per genome are present. each circle contains two rrna transcription units as inverted repeats separated by upstream and downstream spacers. we have studied the replication of this molecule by neutral/neutral two-dimensional gel electrophoresis and ...	1996	8628298
shortened amoebapore analogs with enhanced antibacterial and cytolytic activity.	amoebapores are cytolytic peptides of entamoeba histolytica which function by the formation of ion channels in target cell membranes. three isoforms (amoebapore a, b, and c) exist in amoebic cytoplasmic granules. they are composed of 77 amino acid residues arranged in four alpha-helical domains. in order to analyze the structure-function relationships, 15 synthetic peptides of 24-25 residues were constructed based on the assumption that the third helix is the membrane-penetrating domain and on t ...	1996	8641476
unbiased estimation of symmetrical directional mutation pressure from protein-coding dna.	the most generally applicable procedure for obtaining estimates of the symmetrical, or strandnonspecific, directional mutation pressure (microd) on protein-coding dna sequences is to determine the g+c content at synonymous codon sites (psyn), and to divide psyn by twice the arithmetic mean of the g+c content at synonymous codon sites of a large number of randomly generated, synonymously coding dna sequences (psyn). unfortunately, the original procedure yields biased estimates of psyn and microd ...	1996	8642618
intestinal protozoa.	giardia is the best known cause of protozoal gastrointestinal disease in north america, producing significant but not life-threatening gastrointestinal distress and diarrhea. although diagnosis of giardiasis may be challenging, treatment is usually successful. entamoeba histolytica poses a rarer but far more difficult clinical challenge. dysentery caused by e. histolytica may be the most feared intestinal protozoal infection, although cryptosporidium parvum, balantidium coli, isospora belli, sar ...	1996	8644565
pyrophosphate-dependent phosphofructokinase of entamoeba histolytica: molecular cloning, recombinant expression and inhibition by pyrophosphate analogues.	by using oligonucleotide primers derived from regions highly conserved in prokaryotic and eukaryotic phosphofructokinase sequences, a genomic dna fragment was amplified and used to isolate cdna and genomic clones coding for ppi-dependent phosphofructokinase (ppi-pfk) of entamoeba histolytica. the open reading frame consists of 1308 bp and the corresponding protein has a calculated molecular mass of 47.6 kda. the n-terminal half of the protein shows 27-35% identity with ppi-pfks or atp-dependent ...	1996	8645233
[low digestive hemorrhage caused by amebic colitis].	amebiasis is an infectious disease produced by entamoeba histolytica, which has invasion capacity of the colon mucosa. it has different clinical forms, varying from the asymptomatic carrier state to severe, although not frequent, fulminant or necrotizing colitis, with an important necrosis of the colon mucosa. perforation or intestinal bleeding are possible. we report one case of patient who had a history of recent travel to india. was admitted with a clinical picture of abdominal pain, diarrhea ...	1996	8645519
humoral and mucosal iga antibody response to a recombinant 52-kda cysteine-rich portion of the entamoeba histolytica galactose-inhibitable lectin correlates with detection of native 170-kda lectin antigen in serum of patients with amebic colitis.	humoral and mucosal iga responses to a recombinant cysteine-rich portion (designated lc3) of the entamoeba histolytica galactose-inhibitable lectin's 170-kda subunit were determined in patients with amebic colitis. all patients had 170-kda amebic antigen in serum, compared with 1 of 50 cyst passers and 1 of 31 controls (p < .01). seven days after treatment, serum and fecal 170-kda antigen became undetectable in 12 of the 13 patients (p < .001). serum anti-lc3 iga was found in 83.8% of colitis pa ...	1996	8655985
[the role of aminoglycosides in hiv-infected patients].	the frequency of serious infections due to pseudomonas aeruginosa is increasing among patients with advanced hiv infection; most of the cases are community-acquired. early diagnosis and adequate treatment--usually with the combination of an anti-pseudomonas beta-lactam antibiotic and an aminoglycoside--have a crucial bearing on prognosis. the good in vitro activity of aminoglycosides against mycobacteria contrasts with the need for intravenous administration and toxicity. in patients with mycoba ...	1996	8677419
protozoan infections in the male genital tract.	we reviewed the literature on protozoan infections in the male genital tract, with special reference to histopathological findings and their repercussions on different andrological functions.	1996	8683676
amebiasis and the entamoeba histolytica gal/galnac lectin: from lab bench to bedside.		1996	8689398
antiamoebic activity of piper longum fruits against entamoeba histolytica in vitro and in vivo.	the fruits of piper longum used in traditional remedies against intestinal distress have been tested for their efficacy against experimental caecal amoebiasis of rats. the ethanolic extract, hexane fraction, n-butanol soluble fraction exerted in vitro amoebicidal action at 1000 micrograms/ml and the chloroform fraction at 500 micrograms/ml. the ethanolic extract and piperine, a pure compound, from this plant material cured 90% and 40% of rats with caecal amoebiasis, respectively.	1996	8691851
complementation of an escherichia coli adhe mutant by the entamoeba histolytica ehadh2 gene provides a method for the identification of new antiamebic drugs.	the pathogenic protozoan parasite entamoeba histolytica, the cause of amebic dysentery and amebic liver abscess, is an obligate anaerobe, and derives energy from the fermentation of glucose to ethanol with pyruvate and acetyl coenzyme a as intermediates. we have isolated ehadh2, a key enzyme in this pathway, that is a nad+- and fe2+-dependent bifunctional enzyme with acetaldehyde dehydrogenase and alcohol dehydrogenase activities. ehadh2 is the only known eukaryotic member of a newly defined fam ...	1996	8692838
the influence of conserved aromatic residues on the electron transfer reactivity of 2[4fe-4s] ferredoxins.	the detailed mechanism used by [4fe-4s] ferredoxins to exchange electrons is not known. the importance of two highly conserved aromatic residues, each located close to one cluster of 2[4fe-4s] ferredoxins has been probed by site-directed mutagenesis of clostridium pasteurianum ferredoxin. all generated variants are less stable than the native protein and only hydrophobic residues can replace one of the two conserved aromatic residues. with leucine substituting both aromatics, clostridium pasteur ...	1996	8695647
cloning and expression of a putative alcohol dehydrogenase gene of entamoeba histolytica and its application to immunological examination.	to clone and express the genes encoding major antigens of entamoeba histolytica, we constructed a lambda gt11 cdna library for e. histolytica hm1:imss and screened it with pooled sera from patients with amoebiasis. a 1,223-bp cdna was cloned (clone 1223), and its nucleotide sequence was determined. the amino acid sequence predicted to be encoded by the open reading frame of clone 1223 consisted of 396 residues and showed 32.5 and 32.3% homology to the nadh-dependent butanol dehydrogenases i and ...	1996	8705667
pcr-based quantitation of transfected luciferase dna: evaluation using an entamoeba histolytica reporter construct.		1996	8723913
role of signalling and cytoskeletal rearrangements in the pathogenesis of entamoeba histolytica.	virulence of entamoeba histolytica is characterized by intestinal tissue invasion, engulfment of host cells and the formation of liver abscesses. the actin-rich cytoskeleton of the amoeba allows rapid changes in morphology in response to signals from external stimuli. cellular and molecular studies have described some of the proteins that participate in signalling and in cytoskeletal changes.	1996	8727599
phylogenetic analysis of beta-tubulin sequences from amitochondrial protozoa.	it has been proposed that certain extant anaerobic protozoa are descended from organisms that diverged early in eukaryotic evolution prior to the acquisition of mitochondria. among these are the extracellular parasites giardia lamblia, trichomonas vaginalis, and entamoeba histolytica, and the obligately intracellular microsporidia. phylogenetic analysis of rrna sequences from these amitochondrial organisms suggests that g. lamblia, t. vaginalis, and microsporidia are near the base of the eukaryo ...	1996	8728394
intestinal parasites of humans in a highland community of irian jaya, indonesia.	an indigenous, highland community in the oksibil valley of irian jaya, indonesia, was examined on two occasions to determine the prevalence of intestinal parasites. overall, 478 subjects from three villages in the study area, about 10% of the available population, were sampled. using a standard, wet-mount technique, 15 different species of parasites were found. hookworm was predominant in all age groups, with prevalences of 51%-86%, followed by ascaris lumbricoides (46%-57%) and trichuris trichi ...	1996	8729627
use of the prospect microplate enzyme immunoassay for the detection of pathogenic and non-pathogenic entamoeba histolytica in faecal specimens.	a commercial microplate enzyme immunoassay (prospect eia; alexon inc., sunnyvale, ca 94089, usa) was compared with conventional microscopy for the diagnosis of entamoeba histolytica infection. using specimens known to be infected, the sensitivity of the prospect eia was 78% and its specificity was 99%. no cross reaction with other intestinal parasites was observed. the prospect eia and conventional microscopy (using merthiolate-iodine-formaldehyde direct wet mounts and concentration techniques) ...	1996	8758065
rapid in vitro test for determination of anti-amoebic activity.	a rapid microplate assay for the detection of potential compounds active against entamoeba histolytica is described. the assay is based on the metabolic reduction of a tetrazolium salt by e. histolytica trophozoites as an indicator of their viability which may be measured photometrically. the method was validated by determining the dose-response characteristics of standard amoebicides and correlating optical density and cell number; it provides a convenient means of selecting potentially novel a ...	1996	8761587
entamoeba histolytica: fecal antigen capture immunoassay for the diagnosis of enteric amebiasis by a monoclonal antibody.	amebiasis continues to be of epidemiological importance in underdeveloped countries. clinical diagnosis and epidemiological setting in a region are based on the fecal microscopic identification of cysts or trophozoites. this procedure requires well trained personnel, is laborious, of low sensitivity and frequently yields false-positives results. the present study was designed to develop an immunoenzymatic fecal 96 kda antigen capture test (coproelisa-eh) more sensitive and specific than microsco ...	1996	8762638
[the absence of invasive amebiasis in male homosexual aids patients in recife].	the purpose of this paper was to determine if among male homosexual aids [correction of sida] patients, the entamoeba histolytica was able to product invasive illness. from the 77 investigated patients only one (1.3%) has cysts of e. histolytica in his stools. the electrophoresis of the only isolated strain has shown it was from zimodeme i, non pathogenic. the research of antiamebic antibodies was negative in the serum of the totality of patients. those results showed that even in immunocompromi ...	1996	8768579
production and characterization of murine monoclonal antibodies to blastocystis hominis.	several hybridomas producing antibodies detected by enzyme-linked immunosorbent assay (elisa) were established by fusions of mouse myeloma p3.x63.ag8.u1 with spleen cells from balb/c mice immunized against an isolate of blastocystis hominis. five strongly positive hybrids (6b6, 1d5, 1e7, 4f7 and 4g11) were cloned and all were found to secrete igm monoclonal antibodies. four mabs (6b6, 1e7, 4f7 and 4g11) reacted in immunoblots with a number of b. hominis antigens (mol. wt ranging from 25,000 to 2 ...	1996	8773525
[comparative study on serological diagnosis of entamoebiasis histolytica].	the practicability of four diagnostic methods for entamoebiasis histolytica including micro-gel diffusion precipitin test (mgdp), indirect immunofluorescent antibody test (ifa), indirect hemagglutination test (iha) and enzyme-linked immunosorbent assay (elisa) was evaluated. the serological test methods were compared by using sera obtained from 30 entamoebiasis histolytica patients and 130 normal health individuals. the highest sensitivity was obtained with the method of elisa, followed by ifa a ...	1996	8847819
[recent features of parasites detected from clinical specimens].	it is generally considered that we have already been through with problems caused by various kinds of parasites which had once raged throughout the country. on the contrary to our common concept, we occasionally encounter some kinds of parasites in a laboratory as well as in clinical fields, which have become unfamiliar to us in these days. parasitic diseases are in the first place, proper and limited to certain local regions, but the present situation has been greatly changed. nowadays, specifi ...	1996	8847822
diagnostic tests for amoebic liver abscess: comparison of enzyme-linked immunosorbent assay (elisa) and counterimmunoelectrophoresis (cie).	the liver abscess is the most frequent extraintestinal complication of intestinal amoebiasis: its diagnosis is suggested by the clinical picture but it must be confirmed by paraclinic tests. themost stringent diagnosis requires identification of e. histolytica. but this is possible only in a few cases. serological tests greatly improve the diagnosis of this severe complication of amoebiasis. we compared the enzyme linfed immunosorbent assay and the counterimmunoelectrophoresis techniques. both t ...	1996	8851212
energy production in entamoeba histolytica: new perspectives in rational drug design.	the amebicidal action of metronidazole is activated when the enzyme pyruvate:ferredoxin oxido-reductase transfers reducing equivalents to the nitro group of the drug. the enzyme is present in entamoeba histolytica and other anaerobic parasites like giardia and trichomonas that lack mitochondria. the selectivity of the drug can be ascribed to the absence of the reductase in the human host. e. histolytica possesses other enzymes involved in glucose catabolism that are interesting for the rational ...	1996	8854380
the ultrastructure of entamoeba histolytica locomotion.	this quantitative ultrastructural survey of e. histolytica locomotion in boyden chambers supports the concept that this parasite is capable of random, chemokinetic and chemotactic motility. an e. histolytica committed to chemotaxis will flatten over the filter, accumulate smaller vacuoles at the front of the cell, and will also project pseudopods and its polarized body towards and alongside the chemoattractant axis, respectively. other cell features such as cell polarization, membrane ruffling, ...	1996	8854387
molecular biology of entamoeba histolytica: a review.	amebiasis is one of the main causes worldwide of morbidity and mortality by parasites. application of recombinant dna technology to the study of entamoeba histolytica is bringing new light into our understanding of this remarkable protozoan parasite and of the disease it causes. new achievements affect the way we approach many essential questions about e. histolytica, from the mechanism of its pathogenicity to the definition of e. histolytica as a separate species from the nonpathogenic e. dispa ...	1996	8854402
physiology and molecular biology of multidrug resistance in entamoeba histolytica.	in this paper, we present the most relevant facts on multidrug resistance (mdr) in the protozoan parasite entamoeba histolytica. mdr in e. histolytica presents characteristics similar to transformed mammalian cells. e. histolytica drug resistant mutants show cross-resistance to several drugs, and as in mammalian cells the resistance is reverted by verapamil. six p-glycoprotein-like genes (ehpgp) have been cloned and characterized. apparently, four of these genes are transcribed in drug-resistant ...	1996	8854404
protozoa. amebiasis.	the intestinal protozoan parasite entamoeba histolytica causes amebic dysentery and amebic liver abscess, and ranks third worldwide among parasitic causes of death. the application of molecular techniques to the study of this organism have led to major advances in understanding the pathophysiology of amebic infection. this article reviews what is currently known about the pathogenesis, clinical manifestations, diagnosis, and treatment of amebiasis.	1996	8863036
differentiation of entamoeba histolytica and e. dispar dna from cysts present in stool specimens by polymerase chain reaction: its field application in the philippines.	it has been established that two distinct species exist within what was originally known as entamoeba histolytica. these are e. dispar and e. histolytica, for the nonpathogenic and pathogenic forms, respectively. differentiation of these two organisms is of great clinical importance since they are morphologically indistinguishable and both forms can infect the human intestinal cavity to different degrees. a simple and rapid dna-extraction method that can be used directly on formalin-fixed stool ...	1996	8875564
immunodominant entamoeba histolytica antigens recognized by serum and intestinal antibodies after local or systemic immunization of mice with glutaraldehyde fixed trophozoites.	we performed an immunoblot analysis of the main e. histolytica proteins recognized by immune sera and intestinal fluids of balb/c mice immunized with glutaraldehyde fixed trophozoites (gft) by intragastric, rectal and intraperitoneal routes, to determine if there were differences in the amebic antigens immunodominantly recognized at mucosal and systemic levels. the antigen patterns recognized by mice immunized via intraperitoneal and rectal routes were complex and similar suggesting that the imm ...	1996	8876658
entamoeba invadens: characterization of cysteine proteinases.	cysteine proteinases have a number of important functions in the life cycle of protozoan parasites. based on our previous studies demonstrating the role of cysteine proteinases in invasion by entamoeba histolytica, we evaluated the cysteine proteinases of e. invadens, a related protozoan which causes invasive disease of reptiles. e. invadens readily encysts in axenic culture and provides a model to investigate the role of cysteine proteinases in encystation. broad bands of approximately 130-230, ...	1996	8888735
putative serine/threonine protein kinase expressed in complement-resistant forms of entamoeba histolytica.	entamoeba histolytica is susceptible to complement attack in its lumen-dwelling state and develops complement resistance during pathogenic tissue invasion. as experimental evidence suggests that this change in phenotype is accompanied by a change in gene expression, we constructed a subtractive cdna library to identify genes involved. poly(a) + rna from complement-sensitive trophozoites was subtracted from single stranded cdna derived from complement-resistant ones. transcripts enriched in the l ...	1996	8892294
cell surface molecules of pathogenic and nonpathogenic entamoeba histolytica and their relation to virulence.		1996	8895796
phylogenetic position of kinetoplastid protozoa inferred from the protein phylogenies of elongation factors 1alpha and 2.	partial regions of the mrna encoding a major part of translation elongation factor 2 (ef-2) from a kinetoplastid protozoan, trypanosoma cruzi, were amplified by means of polymerase chain reaction and their primary structures were analyzed. the deduced amino acid sequence was aligned with those of other eukaryotic and archaebacterial ef-2s, and the phylogenetic relationships among eukaryotes were inferred by the maximum likelihood (ml) method. ml analyses of ef-2 phylogeny using six different sto ...	1996	8907178
identification of a 35 kda glycoprotein from entamoeba histolytica by sera from patients with amoebic liver abscess and with mouse monoclonal antibody.	in this work, we explored the relevance of a 35 kda glycoprotein (gm) of the outer membrane from e. histolytica in the diagnosis of the amoebic liver abscess (ala) through elisa and immunoblotting. we were interested in defining the relevance of this antigen in the immune response in patients with amoebic liver abscess and in exploring whether the mouse monoclonal antibody against this 35 kda glycoprotein recognises the same epitope. we found that 87% of ala patients had raised antibody levels t ...	1996	8915688
parasitological and bacteriological studies in recurrent diarrhoea in patients with chronic liver diseases.	sixty patients with chronic liver disease complaining of persistent or recurrent diarrhoea where studied. the stools were examined by direct smear, formol ether concentration method and modified ziehl neelsen technique for cryptosporidium in addition to stool cultures for enteric pathogenic bacteria as salmonella, shigella and e. coli. giardia lamblia was the most prevalent pathogen responsible for diarrhoea in 23.3% of cases followed by entamoeba histolytica in 21.6%, schistosoma mansoni in 5% ...	1996	8918043
evaluation of an antigen-capture enzyme immunoassay for detection of entamoeba histolytica in stool samples.	in order to identify the prevalence of entamoeba histolytica in tourists with diarrhoea returning from countries of the developing world, sensitivity and specificity of a commercially available enzyme immunoassay (eia) kit for the detection of entamoeba histolytica coproantigen in stool were evaluated. five hundred seventy-seven specimens from 469 patients were examined by microscopy and eia. sixty-two specimens from 49 patients were considered positive for entamoeba histolytica. compared with m ...	1996	8922579
[amebic liver abscess--personal observations].	in the period of 1989-1995 seven patients with amebic liver abscess were observed in clinic of infectious diseases of pomeranian medical school in szczecin. the diagnosis has been made on the base of epidemiological data, presence of intrahepatic defect by a scanning procedure of liver (ultrasonography, ct, scintigraphy) and positive serologic test for amebiasis. all patients were male of polish nationality, 29-57 years old, who became ill after travel to africa or india. intestinal amebiasis wa ...	1996	8927739
entamoeba histolytica and entamoeba dispar: differences in numbers and expression of cysteine proteinase genes.	in order to identify molecules that might be responsible for the difference in pathogenicity between the two closely related protozoan parasites entamoeba histolytica and entamoeba dispar, we focussed on cysteine proteinases because this class of enzymes has been considered important for pathogenic tissue destruction. by screening a genomic library derived from an e. histolytica isolate, a total of six distinct genes (ehcp1-ehcp6) encoding typical prepro-forms of cysteine proteinases were identi ...	1996	8930910
codon usage in cryptosporidium parvum differs from that in other eimeriorina.	codon usage of crytosporidium parvum was compared with those of other eimeriorina toxoplasma gondii and eimeria tenella and revealed a biased use of synonymous codons with a preference for nnu (40.0%) and nna (33.4%). there was no close resemblance of the codon usage of c. parvum to t. gondii (correlation coefficient, r = 0.14) or e. tenella (r = 0.14) but it was similar to entamoeba histolytica (r = 0.75) and plasmodium falciparum (r = 0.5). analysis of the codon usage in homologous gene sequen ...	1996	8935947
direct sequencing of the pcr amplified ssu rrna gene of entamoeba dispar and the design of primers for rapid differentiation from entamoeba histolytica.	since 1993, strains of entamoeba histolytica sensu lato have been assigned to 2 species on the basis of clinical, biochemical, immunological and genetic evidence: the pathogenic strains to e. histolytica sensu stricto, the non-pathogenic strains to entamoeba dispar. analysis of the gene encoding for the small subunit ribosomal rna (ssu rdna) supports the existence of 2 species. however, while 3 whole ssu rdna sequences are available in the data bases for e. histolytica, only a partial sequence h ...	1996	8935948
interaction of ls174t human colon cancer cell mucins with entamoeba histolytica: an in vitro model for colonic disease.	colonic mucins secreted by goblet cells protect the colon by preventing the attachment of enteric pathogens to the epithelium. entamoeba histolytica overcomes this protective barrier and causes ulcerations, allowing the parasite to disseminate to the liver and form abscesses. an in vitro model is used to study the interaction between e. histolytica and colonic mucins.	1996	8942726
characterization of ubiquitin genes and -transcripts and demonstration of a ubiquitin-conjugating system in entamoeba histolytica.	we have investigated the genomic organization of entamoeba histolytica ubiquitin and looked for the occurrence of a ubiquitin-conjugating system in this organism. southern blots indicated the presence of > or = 5 ubiquitin-coding regions. one of these, ehubi1, was cloned and sequenced and found to correspond to a monoubiquitin gene; as shown by a polymerase chain reaction, e. histolytica lacked polyubiquitin genes altogether. blots of poly(a)+ rna from exponentially-growing trophozoite cultures ...	1996	8943152
pacsr: a serum replacement for axenic cultivation of entamoeba histolytica.		1996	8944281
luminal bacteria and proteases together decrease adherence of entamoeba histolytica trophozoites to chinese hamster ovary epithelial cells: a novel host defence against an enteric pathogen.	factors that prevent colonic mucosal invasion by pathogenic entamoeba histolytica are not understood. a key initial step in pathogenesis of injury induced by amoeba is adherence to target cells mediated by a surface glycoprotein lectin on e histolytica. mucin degrading bacteria normally present in the colon lumen produce glycosidases that degrade soluble or cell surface glycoconjugates.	1996	8944559
overexpression of p-glycoprotein gene 1 by transfected entamoeba histolytica confers emetine-resistance.		1996	8946391
trypanosoma rangeli and trypanosoma cruzi: molecular characterization of genes encoding putative calcium-binding proteins, highly conserved in trypanosomatids.	genes encoding a 29-kda flagellar calcium-binding protein (f29) in trypanosoma cruzi, strongly homologous to ef-hand calcium-binding protein-encoding genes previously reported in this parasite, were isolated by immunoscreening. f29 is encoded by a number of very similar genes, highly conserved among different t. cruzi isolates. the genes are located on a pair of homologous chromosomes, arranged in one or two clusters of tandem repeats. pcr amplification of trypanosoma rangeli genomic dna, using ...	1996	8948328
presence of a mitochondrial-type 70-kda heat shock protein in trichomonas vaginalis suggests a very early mitochondrial endosymbiosis in eukaryotes.	molecular phylogenetic analyses, based mainly on ribosomal rna, show that three amitochondriate protist lineages, diplomonads, microsporidia, and trichomonads, emerge consistently at the base of the eukaryotic tree before groups having mitochondria. this suggests that these groups could have diverged before the mitochondrial endosymbiosis. nevertheless, since all these organisms live in anaerobic environments, the absence of mitochondria might be due to secondary loss, as demonstrated for the la ...	1996	8962101
heterogeneity of entamoeba histolytica rac genes encoding p21rac homologues.	entamoeba histolytica (eh), the parasite that causes amebic dysentery, is the only protozoan that phagocytoses bacteria, epithelial cells and red blood cells. numerous low-molecular weight gtp-binding proteins, called p21rac, are implicated in signal transduction and actin polymerization during phagocytosis by macrophages and dictyostelium discoideum (dd). here, molecular cloning techniques were used to obtain four eh rac genes that encoded putative p21rac, as well as segments of two eh rac pseu ...	1996	8964500
identification and cellular localization of the actin-binding protein abp-120 from entamoeba histolytica.	several actin-binding proteins participate in the morphological changes that occur during amoeboid movement. the gene encoding one of these proteins, the gelation factor abp-120, was identified and characterized from trophozoites of entamoeba histolytica. the sequence contains 2574 nucleotides, with an open reading frame of 858 amino acids, giving a protein of 93 kda belonging to the spectrin family. the n-terminal domain of abp-120 from e. histolytica revealed a consensus site for actin binding ...	1996	8971707
identification of novel genes from entamoeba histolytica by expressed sequence tag analysis.	shotgun sequencing of cdna clones is now an established approach to gain insight into the expressed nucleotide (nt) sequences in a given cell. we analysed 100 randomly picked cdna clones of the protozoan parasite, entamoeba histolytica, by nt sequencing, with a view to obtain novel gene sequences not detected so far by biochemical and genetic analyses. about 56% of the analysed clones showed significant homology with other genes in the database, including a number of genes whose presence may not ...	1996	8973317
identification and analysis of the u6 small nuclear rna gene from entamoeba histolytica.	among the small nuclear rnas (snrnas) involved in the spliceosomal processing of pre-mrna, u6 is the most conserved. as a first evidence for the presence of the splicing machinery in the amitochondrial protozoan entamoeba histolytica (eh), we have cloned the u6 snrna gene. we find that in this organism u6 is a single copy gene that is transcribed as a poly(a)- rna molecule of approximately 105 nucleotides. we have mapped the 5' end of the u6 snrna transcript, and identified typical elements of a ...	1996	8973344
persistent diarrhea caused by isospora belli: therapeutic response to pyrimethamine and sulfadiazine.	a 54-year-old human immunodeficiency virus (hiv)-positive homosexual man developed overwhelming watery diarrhea and marked weight loss over a 3-week period. although entamoeba histolytica and other nonpathogenic enteric protozoa were observed along with isospora belli in this patient's stool specimens, they were promptly eradicated after metronidazole (flagyl) treatment. the presence of i. belli oocysts in various stages of development in the stool and clinical symptoms related to isospora infec ...	1996	8985661
comparable growth of a trichomonas vaginalis strain in pehps and tyi-s-33 media.	pehps medium, developed for axenic cultivation of entamoeba histolytica and e. invadens, was also capable of supporting the growth of a trichomonas vaginalis strain, with an inoculum of 1 to 100 trichomonads/ml. the logarithmic growth phase in pehps or in tyi-s-33 medium lasted 72 h; yield (3.33 +/- 0.56 x 10(6) trichomonads/ml), duplication time (4.27 h), number of duplications (16.85), or increase ratio (33,328) in pehps medium showed no significant differences with those obtained in tyi-s-33 ...	1996	8987196
antioxidant defense mechanisms in parasitic protozoa.	many of the parasitic protozoa, such as entamoeba histolytica, giardia, trypanosoma, leishmania, and plasmodium, are considered to be anaerobes because they can be grown in vitro only under conditions of reduced oxygen tension. however, these parasitic protozoa have been found to be aerotolerant or microaerophilic, and also to consume oxygen to a certain extent. furthermore, these organisms are highly susceptible to exogenous reactive oxygen species, such as hydrogen peroxide. they must, therefo ...	1996	8989515
seroepidemiology of five major zoonotic parasite infections in inhabitants of sidoarjo, east java, indonesia.	we conducted a seroepidemiological survey of zoonotic parasite infection in inhabitants of east java, indonesia. the subjects of the survey were 244 persons selected from visitors to sidoarjo city hospital in east java between may 1992 and october 1993. ninety-seven had diarrhea and the rest came to the hospital for routine check-ups. all serum samples were tested for antibodies against five zoonotic parasites: toxoplasma gondii, entamoeba histolytica, toxocara canis. angiostrongylus cantonensis ...	1996	9185269
[diarrhea and aids: more complex diagnostic techniques; better therapeutic results].	during 17 months, 73 hiv-positive patients with diarrhea lasting at least for 14 days, were studied prospectively. the patients had stool specimen examinations negative for enteric pathogens, or positive for one of them, but with no response to specific treatment. all patients were subcomitted to digestive endoscopy and biopsies were taken for microbiological and histological studies. the etiology of the diarrhea could be established in 48 patients (66%). in 45, the cause was an enteric infectio ...	1996	9137663
[acute epigastric pain after travel to the tropics. emergency admission of a 28-year-old stewardess].	a 28-year-old stewardess was admitted to hospital with violent cramp-like pain in the right upper abdomen, which was accompanied by a single episode of watery pasty diarrhea. over the next few days her symptoms persisted, she developed a high fever, and her general state of health deteriorated. ultrasonography repeated on the fourth day then revealed a small space-consuming lesion in the right lobe of the liver. while the laboratory investigations initially remained negative, the suspected amebi ...	1996	9119348
[cytochemical study on the activity of enzymes in trophozoites of entamoeba histolytica from the cecum of guinea pigs with invasive and non-invasive amebiasis].	experimental amoebiasis was inflicted on guinea pigs using the ps-2 strain of entamoeba histolytica. cytoenzymatic studies were conducted on the trophozoites sampled from the caecum of hosts with non-invasive and invasive amebiasis. the results show higher intensity of the processes of intracellular digestion, transportation, and anaerobic respiration in the amoebae originating from intestine of the host with infective amoebiasis.	1996	9103051
synthesis and biological activity of platinum group metal complexes of o-vanillin thiosemicarbazones.	o-vanillin-(4-methylthiosemicarbazone), o-vanillin-(4-phenylthiosemicarbazone) and some of their metal complexes of the platinum group have been synthesized, characterized by chemical and spectral methods and studied for their antibacterial, antifungal and amoebicidal activity in vitro. the platinum group metal chelates exibited significant activity against a wide spectrum of microorganisms at different concentrations. the pt(ii) and ru(iii) chelates derived from o-vanillin-(4-phenylthiosemicarb ...	1996	9050213
the sequence and organization of the core histone h3 and h4 genes in the early branching amitochondriate protist trichomonas vaginalis.	among the unicellular protists, several of which are parasitic, some of the most divergent eukaryotic species are found. the evolutionary distances between protists are so large that even slowly evolving proteins like histones are strongly divergent. in this study we isolated cdna and genomic histone h3 and h4 clones from trichomonas vaginalis. two histone h3 and three histone h4 genes were detected on three genomic clones with one complete h3 and two complete h4 sequences. h3 and h4 genes were ...	1996	8995053
oral immunization with a recombinant cysteine-rich section of the entamoeba histolytica galactose-inhibitable lectin elicits an intestinal secretory immunoglobulin a response that has in vitro adherence inhibition activity.	the lc3-encoded 52-kda recombinant protein includes amino acids 758 to 1134 of the 170-kda subunit of the galactose-inhibitable lectin. oral immunization of balb/c mice with the lc3-encoded protein and cholera holotoxin induced an intestinal secretory immunoglobulin a (iga) response (p < 0.01 compared with the control). there was a negative correlation (p = 0.001) between intestinal anti-lc3 iga and serum iga and igg antibody responses. intestinal secretions from immunized mice completely inhibi ...	1996	8606122
cloning and expression of an entamoeba histolytica napd+(-)dependent alcohol dehydrogenase gene.	in this paper we cloned, sequenced and expressed a novel entamoeba histolytica alcohol dehydrogenase gene (ehadh3). ehadh3 has a predicted 383 amino acids open reading frame, encoding for a 42.3 kda protein. the deduced amino acid sequence showed 24 to 26% identity to other type iii alcohol dehydrogenases found in prokaryotic and lower eukaryotic organisms, but not in mammalia. there are at least two ehadh3 gene copies in the genome, but only a 1.2 kb transcript was detected. the ehadh3 fusion p ...	1996	8611619
entamoeba histolytica: gene linkage groups and relevant features of its karyotype.	we identified some gene linkage groups in entamoeba histolytica using a 4-m urea improved transversal alternating field electrophoresis (tafe) method. complex rosette-structured dna molecules were found trapped along the gel lanes, explaining the fuzziness of the patterns. using several episomal probes, including 16 s, 5.8 s, and 25 s ribosomal (r)dna genes, an autonomous replication sequence (ars), and ehvr1, we identified a complete ribosomal episome linkage group (celg) at the 1.2-mb position ...	1996	9003315