Publications

entamoeba histolytica lectins contain unique 6-cys or 8-cys chitin-binding domains.	the jacob lectin, the most abundant glycoprotein in the cyst wall of entamoeba invadens, contains five unique 6-cys chitin-binding domains (cbds). we identified entamoeba histolytica and entamoeba dispar genes encoding jacob homologues, each of which contains two predicted 6-cys cbds. a unique 8-cys cbd was found at the n termini of the e. histolytica chitinase and three other predicted lectins, called jessie 1 to jessie 3. the cbds of four e. histolytica lectins (jacob, chitinase, and jessies 2 ...	2002	12011021
characterization of a rab7-like gtpase, ehrab7: a marker for the early stages of endocytosis in entamoeba histolytica.	we have identified a 667 base pair rab7-like cdna (ehrab7) from entamoeba histolytica. the ehrab7 cdna predicts a polypeptide of at least 206 amino acids with a molecular mass of at least 24.5 kda. alignment of ehrab7 with other rab proteins demonstrated that ehrab7 shared significant homology at the amino acid level with rab7-like proteins from a number of other eukaryotes, suggesting that ehrab7 is a rab7 homolog for e. histolytica. using immunofluorescence microscopy, ehrab7 was demonstrated ...	2002	12034459
how protozoan parasites evade the immune response.	protozoan pathogens such as plasmodium, leishmania, trypanosoma and entamoeba are responsible for several of the most widespread and lethal human diseases. their successful survival depends mainly on evading the host immune system by, for example, penetrating and multiplying within cells, varying their surface antigens, eliminating their protein coat, and modulating the host immune response. immunosuppression is sometimes caused directly by parasite products and sometimes involves antigenic mimi ...	2002	12036742
parasitic diarrhoea in patients with aids.	diarrhoea is a common clinical manifestation of hiv infection regardless of whether or not patients have aids. two newly recognized opportunistic coccidial protozoa are parasitic pathogens in aids patients. we attempted to determine the common parasites in indian patients with aids.	2002	12044119
structure and function of the entamoeba histolytica gal/galnac lectin.	gal/galnac lectin is a novel multifunctional virulence factor of the human parasite entamoeba histolytica. the native protein is a 260-kda heterodimer consisting of a type 1 membrane protein disulfide bonded to a lipid-anchored protein. each subunit has several isoforms that may form functionally different heterodimers, analogous to the integrin family of proteins. recently a second 150-kda gal/galnac lectin has been identified in e. histolytica that associates with the 260-kda lectin. the funct ...	2002	12049210
survey of faecal parasites in patients from western kenya.	faecal specimens were collected from patients complaining of diarrhoea and abdominal or epigastric discomfort at two hospitals. information obtained by questionnaires completed at the time of specimens collection, included demographic and clinical data. specimens were preserved in 10% formalin and polyvinyl alcohol (pva) and examined, as wet mounts and stained with wheatley's trichrome, weber, modified acid-fast and hot safranin stains. one hundred patients were examined, in 30 of them parasites ...	2002	12049246
detection of e. histolytica, g. lamblia and cryptosporidium copro-antigens in stool samples.	a double antibody sandwich elisa technique, using a chromatography purified antisera against e. histolytica, g. lamblia and cryptosporidium antigens, was applied to detect copro-antigens of the corrosponding parasites in 90 patients. all positive cases were diagnosed by parasitological examination and proved to have the infection solely. beside the 90 positive cases, 40 age-matched controls were included in the study, of which 20 individuals were infected with other parasites but not cryptospori ...	2002	12049254
effect of proteasome inhibitors on the growth, encystation, and excystation of entamoeba histolytica and entamoeba invadens.	the effect of three proteasome inhibitors, lactacystin, clasto-lactacystin beta-lactone, and mg-132, on the growth, encystation, and excystation of entamoeba histolytica and entamoeba invadens was examined. all of these drugs blocked e. histolytica growth in a concentration-dependent manner; lactacystin was most potent for the inhibition and mg-132 showed the inhibitory effect only at higher concentrations. e. invadens was more resistant to these drugs than e. histolytica. encystation of e. inva ...	2002	12049464
entamoeba histolytica genomic organization: identification, structure, and phylogenetic relationship of two serine-threonine protein kinases.		2002	12054704
cyst production and transmission of entamoeba and endolimax.	we studied the cyst production of 340 asymptomatic carriers with single or mixed infections of entamoeba histolytica/entamoeba dispar, endolimax nana and entamoeba coli. it was found that the main source of transmission was a small group of 37 (10.9%) carriers who produced 70.2% of all cysts. gender was an important factor for cyst production of ent. histolytica/ent. dispar, since males produced 6-fold more cysts than females. females produced 'large' (13-15 microns) ent. histolytica/ent. dispar ...	2002	12055796
subcellular localization of the nad+-dependent alcohol dehydrogenase in entamoeba histolytica trophozoites.	the protozoan parasite entamoeba histolytica is an ancient eukaryotic cell that shows morphologically atypical organelles and differs metabolically from higher eukaryotic cells. the aim of this study was to determine the subcellular localization of ameba nad+-dependent alcohol dehydrogenase (adh2). the enzyme activity was present in soluble and mainly in particulate material whose density was 1.105 in a sucrose gradient. by differential centrifugation, most of the adh activity sedimented at 160, ...	2002	12058720
lipid metabolism in mucous-dwelling amitochondriate protozoa.	entamoeba, giardia, and trichomonads are the prominent members of a group known as 'mucosal parasites'. while entamoeba and giardia trophozoites colonise the small intestine, trichomonads inhabit the genitourinary tracts of humans and animals. these protozoa lack mitochondria, well-developed golgi complexes, and other organelles typical of higher eukaryotes. nonetheless, they have developed unique metabolic pathways that allow them to survive and multiply in the small intestine and reproductive ...	2002	12062485
[the current status of infectious enteritis in japan--reports of the "research group for infectious enteric diseases, japan" in the last 5 years (1996-2000)].	the patients or carriers with infectious enteritis admitted to the hospitals for infectious diseases in the last 5 years (1996-2000) were studied. the total number of cases admitted in each year were 969, 1,113, 981, 637 and 573 respectively. a total of 1,527 shigella spp. strains including 1,078 strains from overseas travelers' cases were isolated. the isolates of salmonella spp. excluding s. typhi and s. paratyphi a were 562 in number. a total of 61 vibrio cholerae o1 strains including 44 stra ...	2002	12073571
enterotoxigenic escherichia coli as cause of diarrhea among mexican adults and us travelers in mexico.	enterotoxigenic escherichia coli (etec) is the most common pathogen identified in travelers to mexico with diarrhea. there have been few recent studies looking at the etiology of diarrhea in travelers compared with the local resident population.	2002	12088579
intestinal parasites among young children in the interior of guyana.	intestinal parasites contribute greatly to morbidity in developing countries. while there have been several studies of the problem in the caribbean, including the implementation of control programmes, this has not been done for guyana. the aim of this study was to determine the prevalence of intestinal parasites among young children in a town located in the interior of guyana. eighty-five children under the age of 12 years were studied prospectively for intestinal parasites in mahdia, guyana. st ...	2002	12089870
thoracic amebiasis.	pleuropulmonary amebiasis is the common and pericardial amebiasis the rare form of thoracic amebiasis. low socioeconomic conditions, malnutrition, chronic alcoholism, and asd with left to right shunt are contributing factors to the development of pulmonary amebiasis. although no age is exempt, it commonly occurs in patients aged 20 to 40 years, with an adult male to female ratio of 10:1. children rarely develop thoracic amebiasis: when it does occur there is an equal sex distribution. the infect ...	2002	12092041
methods for cultivation of luminal parasitic protists of clinical importance.	cultivation of luminal protistan parasites has a long history. in this review we discuss the methods and media that are most widely used for the establishment and maintenance of the following organisms in culture: entamoeba histolytica, giardia intestinalis, trichomonas vaginalis, dientamoeba fragilis, blastocystis hominis, and balantidium coli. while cultivation is of limited importance in the diagnostic laboratory, it is essential to most research laboratories, and it is toward the latter that ...	2002	12097242
antigenicity and immunogenicity of phage library-selected peptide mimics of the major surface proteophosphoglycan antigens of entamoeba histolytica.	entamoeba histolytica is the protozoan parasite responsible for intestinal amoebiasis and amoebic liver abscess, which cause significant morbidity and mortality in many countries of the world. proteophosphoglycans (ppgs, also known as lipophosphoglycans, lpgs, or lipopeptidophosphoglycans, lppgs) represent dominant surface components of e. histolytica. passive immunization with a monoclonal antibody (eh5) directed against these components protected scid mice from amoebic liver abscess, so ppgs m ...	2002	12102717
in vitro effect of nitazoxanide against entamoeba histolytica, giardia intestinalis and trichomonas vaginalis trophozoites.	nitazoxanide, a 5-nitrothiazolyl derivative, is effective in the treatment of a broad range of parasitic infections. in vitro, it is active against several protozoa, including cryptosporidium parvum, blastocystis hominis, and giardia intestinalis. the objective of this study was to determine the in vitro effect of nitazoxanide on the growth and morphology of three anaerobic protozoa (entamoeba histolytica, giardia intestinalis, and trichomonas vaginalis) and to compare these effects with those o ...	2002	12120985
entamoeba histolytica schaudinn, 1903 and entamoeba dispar brumpt, 1925: differences in their cell surfaces and in the bacteria-containing vacuoles.	entamoeba histolytica schaudinn, 1903 and entamoeba dispar brumpt. 1925 are two of eight species of entamoeba that sometimes inhabit the human colon. the former is an invasive organism capable of causing life-threatening intestinal and extra-intestinal disease: the latter appears not to be invasive. because the two species, when viewed by light microscopy appear morphologically similar, they were long regarded as a single species. however, recent biochemical. immunological, and genetic studies p ...	2002	12120986
synthesis and antiparasitic activity of 1h-benzimidazole derivatives.	compounds 1-18 have been synthesized and tested in vitro against the protozoa giardia lamblia, entamoeba histolytica and the helminth trichinella spiralis. inhibition of rat brain tubulin polymerization was also measured and compared for each compound. results indicate that most of the compounds tested were more active as antiprotozoal agents than metronidazole and albendazole. none of the compounds was as active as albendazole against t. spiralis. although only compounds 3, 9 and 15 (2-methoxyc ...	2002	12127542
[significance of prostaglandins in hepatic amebiasis].	prostaglandins are important mediators of inflammation; they also play a role in the regulation of both lymphocyte and macrophage functions. hamster's liver lesions resulting from intraportal or intrahepatic inoculation of living entamoeba histolytica trophozoites are characterized by an acute inflammatory response, where trophozoites are successively surrounded by polymorphonuclear leukocytes, lymphocytes, and macrophages. incapability of these cells to counteract amebic invasion has been demon ...	2002	12132323
can the efficacy of bacille calmette-guérin tuberculosis vaccine be affected by intestinal parasitic infections?		2002	12134245
fourteen-year seroepidemiological study of zoonoses in a greek village.	a seroepidemiological study carried out in a high-risk village in crete in 1985-1987 and 1998 showed that although the awareness of the people concerning zoonoses had increased during this period, the situation did not improve: there was a significant increase of the spread of seroprevalence in time and space of coxiella burnetii, rickettsia typhi, brucella sp., and entamoeba histolytica. toxoplasma gondii, rickettsia conorii, borrelia burgdorferi, echinococcus granulosus, leishmania sp., and fa ...	2002	12135274
the bittersweet interface of parasite and host: lectin-carbohydrate interactions during human invasion by the parasite entamoeba histolytica.	entamoeba histolytica, as its name suggests, is an enteric parasite with a remarkable ability to lyse host tissues. however, the interaction of the parasite with the host is more complex than solely destruction and invasion. it is at the host-parasite interface that cell-signaling events commit the parasite to (a) commensal, noninvasive infection, (b) developmental change from trophozoite to cyst, or (c) invasion and potential death of the human host. the molecule central to these processes is a ...	2002	12142490
entamoeba histolytica: dna carrier vesicles in nuclei and kinetoplast-like organelles (ehkos).	entamoeba histolytica, the protozoan responsible for human amoebiasis, has a complex genome, whose linear chromosomes and dna circles have so far eluded detailed analysis. we report the detection by transmission electron microscopy of nuclear vesicles (0.05-0.3 microm in diameter) carrying dna in e. histolytica trophozoites. in late anaphase many of these nuclear vesicles were found to be organized in structures of approximately 2.5 x 1 microm, in association with chromosomes and microtubules. i ...	2002	12172801
leishmania donovani phosphofructokinase. gene characterization, biochemical properties and structure-modeling studies.	the characterization of the gene encoding leishmania donovani phosphofructokinase (pfk) and the biochemical properties of the expressed enzyme are reported. l. donovani has a single pfk gene copy per haploid genome that encodes a polypeptide with a deduced molecular mass of 53 988 and a pi of 9.26. the predicted amino acid sequence contains a c-terminal tripeptide that conforms to an established signal for glycosome targeting. l. donovani pfk showed most sequence similarity to inorganic pyrophos ...	2002	12180974
opportunities and obstacles in developing a vaccine for entamoeba histolytica.	the development of a vaccine against entamoeba histolytica, the causative agent of amebic colitis and liver abscess, would reduce childhood mortality in countries such as bangledesh where community-based studies have demonstrated a high prevalence of e. histolytica. immunological studies from this population have shown that protection from amebiasis is associated with mucosal anti-e. histolytica gal/galnac lectin antibodies, suggesting that a vaccine is an achievable goal. however, garnering res ...	2002	12183151
prevalence of intestinal parasitic pathogens in hiv-seropositive individuals in northern india.	to assess the prevalence of intestinal parasitic infections in human immunodeficiency virus (hiv)-seropositive subjects, fecal samples were collected from 120 hiv-seropositive patients and were analyzed for various intestinal parasites. thirty-six patients (30%) were found to harbor an intestinal parasite. cryptosporidium parvum was the most common (10.8%), followed by giardia lamblia (8.3%). cyclospora cayetanensis and blastocystis hominis each were detected in 3.3% of the patients, while isosp ...	2002	12195048
innate and acquired resistance to amebiasis in bangladeshi children.	entamoeba histolytica infection and colitis occurred in 55% and 4%, respectively, of a cohort of bangladeshi preschool children observed for 2 years. dna typing demonstrated that infecting e. histolytica isolates were genetically diverse. innate resistance to infection in children was linked to the absence of serum anti-trophozoite igg. most children who lacked serum anti-trophozoite igg failed to develop it in response to a new infection. the serum anti-trophozoite igg response clustered in fam ...	2002	12195383
[intestinal parasites in african asylum seekers: prevalence and risk factors].	to determine the prevalence of potentially pathogenic intestinal parasites in asylum seekers coming from a highly endemic area, and to identify groups of asylum seekers from africa with a high risk of an intestinal parasitic infestation which is potentially harmful of their own health or that of those in their vicinity.	2002	12198830
epidemiology of amebiasis in a region of high incidence of amebic liver abscess in central vietnam.	the recent identification of entamoeba dispar as a separate species, which is nonpathogenic for humans but morphologically indistinguishable from entamoeba histolytica, has prompted the world health organization to recommend reinforced efforts for reassessment of the epidemiology of amebiasis and, in particular, of e. histolytica. in this regard, the distribution of amebic liver abscess (ala) cases were analyzed in the province of thua thien hué (tt hué) in central vietnam, a region known for it ...	2002	12201594
construction and immunogenicity of a codon-optimized entamoeba histolytica gal-lectin-based dna vaccine.	invasive amebiasis caused by entamoeba histolytica is the third leading parasitic cause of mortality, and there are no vaccines available to help control the disease. the galactose-adherence lectin (gal-lectin) is the parasite's major molecule allowing it to adhere to colonic mucin for colonization and to target cells for tissue destruction. it is immunodominant and is regarded as the most promising candidate molecule to be included in a subunit vaccine against amebiasis. in this study, we are r ...	2002	12213393
a patient with intestinal amoebiasis and cutaneous amoebic ulcer.	this paper reports a patient with intestinal amoebiasis in concomitant with amoebic ulcer in the thigh. the ulcer was suspected to be carcinoma, complicated cutaneous leishmaniasis or due to free-living amoebae. the diagnosis was confirmed by the pathological and parasitological demonstration of haematophagous trophozoites of e. histolytica. the patient was successfully treated with metronidazole.	2002	12214920
[utility of studying feces for the diagnosis and management of infants and preschool children with acute diarrhea].	to analyze the results of a stool work-up protocol in a series of infants and preschoolers with acute diarrhea.	2002	12216520
differentiation of entamoeba histolytica/entamoeba dispar by pcr and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.	to correlate a particular state of immunity with entamoeba spp., we used colorimetric pcr to differentiate e. histolytica from e. dispar in individuals with amoebiasis and to associate its presence with the clinical profile, including humoral and cellular immune responses to e. histolytica. our results showed high levels of antibody in acute amoebiasis and elevation of il-4 production, a cytokine related to th2 profile, associated with e. histolytica. in chronic amoebiasis, even with anti-e. his ...	2002	12224582
seasonal prevalence of intestinal parasites in the united states during 2000.	one-third of 5,792 fecal specimens from 2,896 patients in 48 states and the district of columbia tested positive for intestinal parasites during the year 2000. multiple infections with 2-4 parasitic species constituted 10% of 916 infected cases. blastocystis hominis infected 662 patients (23% or 72% of the 916 cases). its prevalence appears to be increasing in recent years. eighteen other species of intestinal parasites were identified. cryptosporidium parvum and entamoeba histolytica/e. dispar ...	2002	12224595
a monoclonal antibody to the amebic lipophosphoglycan-proteophosphoglycan antigens can prevent disease in human intestinal xenografts infected with entamoeba histolytica.	entamoeba histolytica trophozoites are covered by lipophosphoglycan-peptidoglycan molecules which may be key virulence factors. we found that pretreatment of severe combined immunodeficient mice bearing human intestinal xenografts with a monoclonal antibody to the amebic lipophosphoglycan-peptidoglycan molecules can prevent or significantly reduce the human intestinal inflammation and tissue damage that are normally seen with e. histolytica colonic infection.	2002	12228321
signal transduction in entamoeba histolytica induced by interaction with fibronectin: presence and activation of phosphokinase a and its possible relation to invasiveness.	interaction of entamoeba histolytica trophozoites with extracellular matrix (ecm) proteins activates signaling pathways through g-protein-coupled receptors. increments of adenylyl cyclase activity and camp produce a striking reorganization of actin into structures that apparently facilitate adhesive, locomotive, and secretory activities. the reorganization of actin is induced by phosphorylation of actin-associated proteins by diverse kinases activated during the signaling process. although camp- ...	2002	12234529
a cross-sectional study of intestinal parasitic infections among schoolchildren in nan province, northern thailand.	a cross-sectional study of the prevalence of intestinal parasitic infections at eight schools in bo klau district and four schools in chalerm prakiet district, nan province, in january and february, 2001. a total of 1,010 fecal samples were examined using the formalin-ether sedimentation technique. results revealed that the rate of helminthic infection was 60.0%, while protozoa accounted for 36.2% of infections; mixed infections were common, resulting in a total prevalence of both parasites of 6 ...	2002	12236415
fructose-1,6-bisphosphate aldolases in amitochondriate protists constitute a single protein subfamily with eubacterial relationships.	sequences of putative fructose-1,6-bisphospate aldolases (fba) in five amitochondriate unicellular eukaryotes, the diplomonads giardia intestinalis (published earlier) and spironucleus barkhanus, the pelobiont mastigamoeba balamuthi,the entamoebid entamoeba histolytica, and the parabasalid trichomonas vaginalis all belong to class ii of fbas and are highly similar to each other (>48% amino acid identity). the five protist sequences, however, do not form a monophyletic group. diplomonad fbas shar ...	2002	12242011
entamoeba histolytica: immunohistochemical study of hepatic amoebiasis in mouse. neutrophils and nitric oxide as possible factors of resistance.	studies in mice have not rendered conclusive data on cell and humoral factors to support the resistance of this rodent to entamoeba histolytica infection. in balb/c and c3h/hej mice inoculated with live or fixed trophozoites, we studied the evolution of the hepatic lesion, the kinetics of inflammatory cells, and the participation of some humoral factors in the development of the hepatic amoebic lesion. from the first hour, amoebae were surrounded by neutrophils containing inducible nitric oxide ...	2002	12243737
structure and inactivation of triosephosphate isomerase from entamoeba histolytica.	triosephosphate isomerase (tim) has been proposed as a target for drug design. tims from several parasites have a cysteine residue at the dimer interface, whose derivatization with thiol-specific reagents induces enzyme inactivation and aggregation. tims lacking this residue, such as human tim, are less affected. tim from entamoeba histolytica (ehtim) has the interface cysteine residue and presents more than ten insertions when compared with the enzyme from other pathogens. to gain further insig ...	2002	12270704
amebic infections due to the entamoeba histolytica-entamoeba dispar complex: a study of the incidence in a remote rural area of ecuador.	an epidemiologic field study was conducted in the village of borbòn in esmeraldas province in northern ecuador to compare different parasitologic methods in the diagnosis of infection with the entamoeba histolytica/entamoeba dispar complex. the results of two stool antigen detection assays (the prospect entamoeba histolytica microplate assay and the e. histolytica ii assay) were compared with isoenzyme characterization of the amebic isolates. nearly all (176 of 178, 98.9%) subjects were positive ...	2002	12363056
the mouse model of amebic colitis reveals mouse strain susceptibility to infection and exacerbation of disease by cd4+ t cells.	amebic colitis is an important worldwide parasitic disease for which there is not a well-established animal model. in this work we show that intracecal inoculation of entamoeba histolytica trophozoites led to established infection in 60% of c3h mice, while c57bl/6 or balb/c mice were resistant, including mice genetically deficient for il-12, ifn-gamma, or inducible no synthase. infection was a chronic and nonhealing cecitis that pathologically mirrored human disease. characterization of the infl ...	2002	12370386
lines and sine-like elements of the protist entamoeba histolytica.	a survey of whole genome shotgun sequences of the protozoan parasite entamoeba histolytica revealed three families of non-long terminal repeat (ltr) retrotransposons or long interspersed elements (lines) (called ehlines in this report). the 4.8 kb ehlines each had a single open reading frame with a putative nucleic acid binding motif (cchc) and restriction enzyme-like endonuclease domain located downstream of the reverse transcriptase (rt) domain. phylogenetic analysis of the rt domain placed th ...	2002	12384304
primary cutaneous amoebiasis: case report with review of the literature.	primary cutaneous amoebiasis is a rare clinical entity. the lesions can be successfully treated if suspected and correctly diagnosed. we report an interesting case with review of the literature.	2002	12390191
[what tests are needed to diagnosis amebiasis?].		2002	12395743
treatment of asymptomatic intestinal entamoeba histolytica infection.		2002	12397207
amebic liver abscess.	amebic liver abscess should be suspected in travelers returning from endemic areas or in immunocompromised patients who present with fever, right upper quadrant pain, hepatomegaly, and a liver lesion on an imaging study. rapid initiation of therapy without serologic confirmation of infection, if necessary, is important to minimize complications. metronidazole is given orally or intravenously for 14 days. the drug is generally well tolerated and leads to resolution of symptoms in most patients wi ...	2002	12408781
remarkable genetic polymorphism among entamoeba histolytica isolates from a limited geographic area.	in order to understand genetic polymorphisms among entamoeba histolytica strains in a limited geographic area and among restricted social populations, we studied nucleotide polymorphism in dna regions that do not encode proteins (locus 1-2 and locus 5-6) and in genes coding for chitinase and for serine-rich e. histolytica protein. thirty e. histolytica isolates from domestically infected japanese amebiasis patients (male homosexuals and residents in institutions for the mentally handicapped) and ...	2002	12409379
potential antiamoebic property of the roots of piper longum linn.	in an earlier study we reported the effect of ethanol extracts of piper longum fruit against caecal amoebiasis in rats. a follow-up study to determine whether the roots possess similar antiamoebic activity was carried out. the ethanolic extract of roots was amoebicidal at 1,000 microg/ml in vitro and cured 88% of caecal amoebiasis cases, suggesting that both the root and fruit of p. longum possess antiamoebic activity to approximately the same extent.	2002	12410557
[multiple drug resistance in entamoeba histolytica].		2002	12415960
synthesis and in vitro antiprotozoal activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazone derivatives.	several thiosemicarbazone derivatives of 5-nitrothiophene-2-carboxaldehyde were prepared by the simple process in which n(4)-thiosemicarbazone moiety was replaced by aliphatic, arylic and cyclic amine. among these thiosemicarbazones compound 11 showed significant antiamoebic activity whereas compound 3 was more active antitrichomonal than the reference drug.	2002	12419387
multidrug resistance in the protozoan parasite entamoeba histolytica.	in this review we discuss the mechanisms and molecules involved in the multidrug resistance (mdr) of the protozoan parasite entamoeba histolytica. drug resistant mutants exhibited the main characteristics presented by the mdr mammalian cells. they showed cross-resistance to several unrelated drugs that is reverted by calcium channel blockers. mdr phenotype in e. histolytica is regulated at a transcriptional level by the ehpgp1 gene, which is constitutively expressed and by the ehpgp5 gene, whose ...	2002	12421633
two ccaat/enhancer binding protein sites are cis-activator elements of the entamoeba histolytica ehpgp1 (mdr-like) gene expression.	here, we show the relevance of promoter regions (-74 to +24, -167 to -75 and -259 to -168 bp) in the transcriptional activation of the multidrug resistance gene ehpgp1 in entamoeba histolytica, using mutated plasmids and transfection assays. we also demonstrate that both ccaat/enhancer binding protein sites (-54 to -43 bp and -198 to -186 bp) are cis-activating elements of gene expression in the drug-resistant (clone c2) and -sensitive (clone a) trophozoites. nuclear proteins from trophozoites o ...	2002	12427095
a rho-like small gtpase of entamoeba histolytica contains an unusual amino acid residue in a conserved gdp-stabilization region and is not a substrate for c3 exoenzyme.	the entamoeba histolytica small gtp-binding protein ehrho1 has an unusual amino acid residue at a conserved site found in all known ras superfamily proteins. ehrho1 has an isoleucine at position 45, which corresponds to position 28 of human ras and rac and position 30 of human rho and cdc42. all other known small gtpases have an aromatic residue (typically phenylalanine) at this position, and mutation to a leucine renders other ras proteins constitutively active by reason of diminished affinity ...	2002	12427464
entamoeba histolytica: sequence conservation of the gal/galnac lectin from clinical isolates.	the gal/galnac lectin gene of entamoeba histolytica is a major amebic virulence protein responsible for interaction with host tissues. we investigated sequence differences in the gal/galnac lectin heavy subunit in three isolates from bangladesh and one isolate from georgia, each of which was determined to be genetically distinct by srehp alui digestion. interestingly, we observed only slight genetic diversity in the lectin gene as compared with the hm1:imss laboratory strain, originally a clinic ...	2002	12427470
endemic invasive amoebiasis in northern australia.		2002	12429010
characterization of entamoeba histolytica antigens in circulating immune complexes in sera of patients with amoebiasis.	isolated circulating immune complexes (cics) from sera of patients with amoebiasis were characterized to determine entamoeba histolytica antigens that participate in the disease process. in total, 116 serum samples were collected before starting anti-amoebic therapy, and their cics were isolated by differential polyethylene glycol precipitation. the presence of amoeba-specific antigens in cics was detected by antigen capture enzyme-linked immunosorbent assay (elisa) and by immunoblot assay. anti ...	2002	12430757
preliminary morphological study of the effects produced by a methanolic extract of castela texana.		2002	12434567
the abundant polyadenylated transcript 2 dna sequence of the pathogenic protozoan parasite entamoeba histolytica represents a nonautonomous non-long-terminal-repeat retrotransposon-like element which is absent in the closely related nonpathogenic species entamoeba dispar.	while comparing gene expression in the pathogenic organism entamoeba histolytica and the closely related but nonpathogenic species entamoeba dispar, we discovered that the e. histolytica abundant polyadenylated transcript 2 (ehapt2) and corresponding genomic copies are absent in e. dispar. although polyadenylated, ehapt2 does not contain any overt open reading frame. southern blot and sequence analyses revealed that about 500 copies of ehapt2 genomic elements were present in each cell and that t ...	2002	12438355
anti-inflammatory, analgesic and antiamoebic activity evaluation of pyrimido[1,6-a]benzimidazole derivatives synthesized by the reaction of ketoisothiocyanates with mono and diamines.	(un) substituted o-phenylenediamines 1a-g reacted with 3-isothiocyanatobutanal to give pyrimidobenzimidazole derivatives, 2a-g, respectively. products 4, 6 and 8, 10 were obtained by condensation of 3-isothiocyanatobutanal with 2,3-diaminopyridine, 1,4-diaminobutane and 3-isothiocyanatopropanal with 4,5-dimethyl-1,2-phenylenediamine, o-nitroaniline, respectively. s-methylation of 2f and 11b gave products 12a and 12b, respectively. anti-inflammatory and analgesic activity evaluations of 2a-g and ...	2002	12446042
some gastro-intestinal tract parasites in wild de brazza's monkeys (cercopithecus neglectus) in kenya.	fresh faecal droppings of wild group of de brazza's monkeys (cercopithecus neglectus), earmarked for translocation, were collected between january and july 1998. the samples were analysed using direct smears, ether-sedimentation and the harada-mori culture techniques for gastro-intestinal tract parasites (git). two species of helminths and three of protozoa were detected. entamoeba coli was found in all 40 samples screened from 11 monkeys. entamoeba histolytica was detected in 71.8% of the total ...	2002	12446101
the calcium-binding protein of entamoeba histolytica as a fusion partner for expression of peptides in escherichia coli.	we describe the construction of an escherichia coli expression vector, cbp that allows the c-terminal fusion of heterologous proteins to the calcium-binding protein (cabp) of the parasitic protozoan entamoeba histolytica. the intrinsic nature of this protein to remain soluble on heat treatment has been exploited in its use as a novel fusion partner. the presence of a histidine tag and an enterokinase recognition site, aid in the affinity purification and proteolytic cleavage of the fusion protei ...	2002	12452805
real-time pcr for detection and differentiation of entamoeba histolytica and entamoeba dispar in fecal samples.	a closed-tube, real-time pcr assay was developed for sensitive and specific detection and differentiation of the two closely related intestinal protozoan parasites entamoeba histolytica and entamoeba dispar directly from human feces. the assay is performed with the lightcycler system using fluorescence-labeled detection probes and primers amplifying a 310-bp fragment from the high-copy-number, ribosomal dna-containing ameba episome. the assay was able to detect as little as 0.1 parasite per g of ...	2002	12454128
evidence for lateral transfer of genes encoding ferredoxins, nitroreductases, nadh oxidase, and alcohol dehydrogenase 3 from anaerobic prokaryotes to giardia lamblia and entamoeba histolytica.	giardia lamblia and entamoeba histolytica are amitochondriate, microaerophilic protists which use fermentation enzymes like those of bacteria to survive anaerobic conditions within the intestinal lumen. genes encoding fermentation enzymes and related electron transport peptides (e.g., ferredoxins) in giardia organisms and amebae are hypothesized to be derived from either an ancient anaerobic eukaryote (amitochondriate fossil hypothesis), a mitochondrial endosymbiont (hydrogen hypothesis), or ana ...	2002	12455953
in vitro activity of nitazoxanide and related compounds against isolates of giardia intestinalis, entamoeba histolytica and trichomonas vaginalis.	the activities of the n-(nitrothiazolyl) salicylamide nitazoxanide and its metabolite tizoxanide were compared with metronidazole in vitro in microplates against six axenic isolates of giardia intestinalis. tizoxanide was eight times more active than metronidazole against metronidazole-susceptible isolates and twice as active against a resistant isolate. in 10 axenic isolates of entamoeba histolytica, while tizoxanide was almost twice as active as metronidazole against more susceptible isolates, ...	2002	11751773
cysteine proteinases from distinct cellular compartments are recruited to phagocytic vesicles by entamoeba histolytica.	cysteine proteinases, which are encoded by at least seven genes, play a critical role in the pathogenesis of invasive amebiasis caused by entamoeba histolytica. the study of these enzymes has been hampered by the inability to obtain significant quantities of the individual native proteinases. we have now expressed functionally active recombinant acp1 (ehcp3) and acp2 (ehcp2) proteinases in baculoviral expression vectors. the purified recombinant acp1 and acp2 proteinases exhibited similar activi ...	2002	11755183
the presence of antiamoebic constituents in psyllium husk.	the crude extract of psyllium husk (ispaghula) and its active constituent (petroleum fraction) caused varying degrees of growth inhibition in three different species of entamoeba, i.e. entamoeba histolytica, e. invadens and e. dispar. the inhibitory effect of the crude extract was in the dose range of 1-10 mg/ml, whereas a similar inhibitory effect was obtained with the petroleum fraction at a much lower dose (0.1-1.0 mg/ml), indicating that the active chemical(s) is/are concentrated in the petr ...	2002	11807972
recombinant expression and purification of an enzymatically active cysteine proteinase of the protozoan parasite entamoeba histolytica.	cysteine proteinases and in particular cysteine proteinase 5 (ehcp5) of entamoeba histolytica are considered important for ameba pathogenicity. to study ehcp5 in more detail a protocol was elaborated to produce considerable amounts of the enzyme in its active form. the protein was expressed in escherichia coli as a histidine-tagged pro-enzyme and purified to homogeneity under denaturing conditions in the presence of guanidine-hcl using nickel affinity chromatography. renaturation was performed b ...	2002	11812234
context-dependent roles of the entamoeba histolytica core promoter element gaac in transcriptional activation and protein complex assembly.	transcriptional control of the hgl5 gene of entamoeba histolytica is mediated through an unusual core promoter composed of tata, gaac and initiator elements. in the hgl5 promoter the gaac element (aatgaact) determines the site and rate of transcription initiation. here we tested the role of the gaac element in transcription activation from upstream regulatory elements (ures) in the hgl5 promoter. we also examined the function of the gaac element in the ferredoxin (fdx) promoter and characterized ...	2002	11849710
delinking of s phase and cytokinesis in the protozoan parasite entamoeba histolytica.	the alternation of dna replication in s phase and chromosome segregation in m phase is a hallmark in the cell cycle of most well-studied eukaryotes and ensures that the progeny do not have more than the normal complement of genes and chromosomes. an exception to this rule has been described in cancer cells that occasionally become polyploid as a result of failure to restrain s phase despite the failure to undergo complete mitosis. here, we describe the cell division cycle of the human pathogen, ...	2002	11856173
thermophilic alcohol dehydrogenase from the mesophile entamoeba histolytica: crystallization and preliminary x-ray characterization.	the tetrameric nadp(+)-dependent secondary alcohol dehydrogenase from entamoeba histolytica has been crystallized in its apo form. the crystals belong to space group c222(1), with unit-cell parameters a = 76.89, b = 234.24, c = 96.24 a, and diffract to 1.9 a at liquid-nitrogen temperature. analysis of the patterson self-rotation function shows that the crystals contain one dimer per asymmetric unit.	2002	11856851
mitochondrial-type hsp70 genes of the amitochondriate protists, giardia intestinalis, entamoeba histolytica and two microsporidians.	genes encoding putative mitochondrial-type heat shock protein 70 (mit-hsp70) were isolated and sequenced from amitochondriate protists, giardia intestinalis, entamoeba histolytica, and two microsporidians, encephalitozoon hellem and glugea plecoglossi. the deduced mit-hsp70 sequences were analyzed by sequence alignments and phylogenetic reconstructions. the mit-hsp70 sequence of these four amitochondriate protists were divergent from other mit-hsp70 sequences of mitochondriate eukaryotes. howeve ...	2002	11880223
deficiency of antibody responses to t-independent antigens in gerbils---meriones unguiculatus.	meriones unguiculatus commonly known as gerbils are widely used as animal models for a variety of parasitic infections such as brugia malayi, entamoeba histolytica, giardia duodenalis, toxoplasma gondi, helicobacter pylori, strongyloides stercoralis and echinococcus multilocularis. groups of balb/c mice, gerbils and xid mice were studied for antibody responses to t-independent antigens. gerbils were found to be significantly deficient in eliciting antibodies to both dextran and phosphorylcholine ...	2002	11888652
entamoeba histolytica-induced dephosphorylation in host cells.	activation of host cell protein tyrosine phosphatases (ptpases) and protein dephosphorylation is an important mechanism used by various microorganisms to deactivate or kill host defense cells. to determine whether protein tyrosine dephosphorylation played a role in signaling pathways affecting entamoeba histolytica-mediated host cell killing, we investigated the involvement of ptpases during the attachment of e. histolytica to target cells. we observed a rapid decrease in cellular protein tyrosi ...	2002	11895943
the phylogenetic position of the pelobiont mastigamoeba balamuthi based on sequences of rdna and translation elongation factors ef-1alpha and ef-2.	the taxonomic position and phylogenetic relationships of the pelobionta, an amitochondriate amoeboflagellate group, are not yet completely settled. to provide more information, we obtained sequences for the large subunit rdna gene, the gene for translation elongation factor 1alpha, and for a large part of the gene encoding translation elongation factor 2 from a representative of this group, mastigamoeba balamuthi (formerly phreatamoeba balamuthi). the gene for the large subunit rdna was unusuall ...	2002	11908892
simultaneous differentiation and typing of entamoeba histolytica and entamoeba dispar.	sequences corresponding to some of the polymorphic loci previously reported from entamoeba histolytica have been detected in entamoeba dispar. comparison of nucleotide sequences of two loci between e. dispar strain saw760 and e. histolytica strain hm-1:imss revealed significant differences in both repeat and flanking regions. the tandem repeat units varied not only in sequence but also in number and arrangement between the two species at both the loci. using the sequences obtained, primer pairs ...	2002	11923344
entamoeba histolytica: clinical update and vaccine prospects.	amebiasis is extraordinarily common in children of the developing world. this realization has come from application of diagnostic techniques that distinguish the nonpathogenic parasite entamoeba dispar from entamoeba histolytica. e. histolytica infection is found in children with dysentery, diarrhea, and in many cases in children with no gastrointestinal symptoms. genetically distinct strains of e. histolytica exist but evidence is too preliminary to judge if some strains are more virulent than ...	2002	11927043
dna polymorphism in north indian isolates of entamoeba histolytica detected by pcr fingerprinting.	entamoeba histolytica infection in humans is still one of the leading causes of parasitic diseases among the developing countries, including india. it therefore becomes extremely important to characterize this parasite with the aim of preventing and controlling the amoebiasis which it causes. the present study describes for the first time the ability of random amplified polymorphic dna (rapd)-pcr fingerprinting strategies to subtype amoebae and to detect considerable genetic variability present ...	2002	11936500
an anti-contamination cocktail for the in vitro isolation and cultivation of parasitic protozoa.	contamination by bacteria or fungi is a frequent problem with the in vitro isolation and propagation of protozoan parasites. we developed an antibiotic combination of broad anti-contaminant activity but minimal toxicity to protozoa. this anti-contamination cocktail consists of penicillin g (60 microgml(-1)), kanamycin (100 microgml(-1)), chloramphenicol (10 microgml(-1)) and flucytosine (50 microgml(-1)). it is well tolerated by african and south american trypanosomes, leishmania spp., giardia d ...	2002	11936508
n-terminal n-myristoylation of proteins: refinement of the sequence motif and its taxon-specific differences.	n-terminal n-myristoylation is a lipid anchor modification of eukaryotic and viral proteins targeting them to membrane locations, thus changing the cellular function of modified proteins. protein myristoylation is critical in many pathways; e.g. in signal transduction, apoptosis, or alternative extracellular protein export. the myristoyl-coa:protein n-myristoyltransferase (nmt) recognizes the sequence motif of appropriate substrate proteins at the n terminus and attaches the lipid moiety to the ...	2002	11955007
early interactions of entamoeba histolytica trophozoites with parenchymal and inflammatory cells in the hamster liver: an immunocytochemical study.	we studied the early in situ interactions of live and fixed entamoeba histolytica trophozoites with hamster hepatic parenchymal and inflammatory cells using immunoperoxidase and immunoelectronmicroscopy. close contact between trophozoites and endothelial cells and the diffusion of amoebic molecules from trophozoites towards nearby endothelial cells and distant hepatocytes were observed. the inflammatory cells around the amoebae and the remnants of parenchymal cells and hepatocytes located close ...	2002	11958565
synthesis, characterization and antiamoebic activity of benzimidazole derivatives and their vanadium and molybdenum complexes.	reaction of [moo(2)(acac)(2)] (where, acac=acetyl acetone) and kvo(3) with 2-(salicylidieneimine) benzimidazole lead to form new complexes [moo(2)(sal-bmz)(2)] and k [vo(2)(sal-bmz)(2)] [where, sal-bmz=2-(salicylidieneimine) benzimidazole], which showed the monobasic bidentate nature of the ligand in which the phenolic oxygen and the imine nitrogen of the ligand are coordinated to the metal ion. these complexes were characterized along with nine other complexes of oxoperoxovanadium (v), molybden ...	2002	11958982
pore-forming polypeptides of the pathogenic protozoon naegleria fowleri.	the free-living amoeboflagellate and potential human pathogen naegleria fowleri causes the often fatal disease primary amoebic meningoencephalitis. the molecular repertoire responsible for the cytolytic and tissue-destructive activity of this amoeboid protozoon is largely unknown. we isolated two pore-forming polypeptides from extracts of highly virulent trophozoites of n. fowleri by measuring their membrane-permeabilizing activity. n-terminal sequencing and subsequent molecular cloning yielded ...	2002	11948186
diagnosis of amoebic colitis by antigen capture elisa in patients presenting with acute diarrhoea in cairo, egypt.	we studied 84 consecutive patients presenting with acute diarrhoea (less than 1 week in duration) at an outpatient tropical medicine clinic in cairo, egypt. the diagnosis of amoebic colitis was established by the presence of entamoeba histolytica galactose-inhibitable lectin antigen and the presence of occult blood in stool. controls were 182 healthy regional people and 64 patients complaining of prolonged diarrhoea lasting more than 1 week. entamoeba histolytica infection was found more frequen ...	2002	11952953
entamoeba histolytica: intracellular distribution of the proteasome.	we have studied the intracellular distribution of proteasome subunits, corresponding to the catalytic (20s) core and the regulatory (19s) cap, in the extracellular protozoan parasite entamoeba histolytica. contrary to all cell types described to date, notably mammalian and yeast, in which the proteasome is found in the nucleus and actively imported into it, microscopic analysis and subcellular fractionation of e. histolytica trophozoites show that the proteasome is absent from the nucleus of the ...	2002	12856315
a comparative study of the intestinal parasites prevalent among children living in rural and urban settings in and around chennai.	a comparative analysis of the various intestinal parasites detected among children attending schools was carried out in a rural and urban location in and around chennai. a total of 324 stool samples were examined by routine microscopy using normal saline and lugol's iodine preparation as well as by saturated sodium chloride flotation technique. all suspicious samples were subjected to zinc sulphate concentration technique as well as modified ziehl neelson stain and trichrome stains to identify t ...	2002	12718339
intestinal parasites in children with diarrhea in delhi, india.	the parasitic causes of diarrhea in children in delhi were determined by the direct smear technique; stool specimens of 127 children were examined for intestinal parasites. in 59 cases (46.5%) intestinal helminths and protozoa were demonstrated. ascaris lumbricoides was observed in 1 (0.8%) case, while trichuris trichiura was the finding in 3 (2.4%). protozoal parasites included giardia intestinalis and entamoeba histolytica in 14 (11%) cases each, balantidium coli in 3 (2.4%) cases and cryptosp ...	2002	12757217
antiamoebic chemoprophylaxis using quinfamide in children: a comparative study.	this study sought to examine whether the administration of quinfamide at 3- or 6-month intervals diminished the frequency of entamoeba histolytica cysts in stool samples compared to controls. the prospective, longitudinal, randomized, single-blind study examined children from six primary schools in celaya and neutla, guanajuato. of the 1,524 students in these schools, we selected participants for the study as follows: children were included in the study if their parents agreed in writing to the ...	2002	12805964
[amebic liver abscess. surgical treatment].		2002	12733337
entamoeba histolytica: rapid identification and differentiation of indian isolates by riboprinting.	entamoeba histolytica infection still remains one of the major public health problem for developing countries like india. a rapid and accurate detection of this parasite is essential for prevention and control of amoebiasis. in this study, using the method of 'riboprinting' (pcr-rflp of rrna genes from amoeba) we have analysed 15 stool samples from symptomatic patients of amoebiasis. all 15 patients of clinical amoebiasis had e. histolytica in their stool and two of the samples also showed mixed ...	2002	12706746
gerd like symptoms as seen in a village.	twenty cases of protozoal infection presented with symptoms suggesting gerd. treatment with antacids and h2 blockers was unsuccessful in giving them relief. as they had also protozoal infection, treatment with anti-protozoal drugs gave them complete relief in the follow up period of one year after the end of treatment. hence we have named these conditions simulating peptic ulcer gerd as pseodogerd or protozoal gerd. it is suggested that the person presenting with the symptoms of gerd in our area ...	2002	12645160
synthesis, antiprotozoal and anticancer activity of substituted 2-trifluoromethyl- and 2-pentafluoroethylbenzimidazoles.	the synthesis of several halogenated benzimidazoles substituted in position 2 with trifluoromethyl, pentafluoroethyl and 2-thioethylaminodimethyl group is reported. antiprotozoal and anticancer activity of series of newly synthesized and previously obtained compounds was studied. all of tested bezimidazoles showed remarkable antiprotozoal activity against giardia intestinalis, entamoeba histolytica and trichomonas vaginalis. of the studied collection of halogenated benzimidazoles the most antica ...	2002	12660022
intestinal parasitic infections in bekasi district, west java, indonesia and a comparison of the infection rates determined by different techniques for fecal examination.	this study was undertaken to determine the current status of intestinal parasitic infections among schoolchildren in west java, indonesia, and to compare the infection rates obtained by three different methods of fecal examination. a total of 285 fecal samples were collected from 131 males and 154 females at a junior high school. samples were brought to the department of parasitology, faculty of medicine, university of indonesia, and were examined for parasites by the kato-katz thick smear metho ...	2002	12693577
[the phagocytic activity of blood platelets in different parasitic diseases].	blood platelets take part in immune reactions of the organism, especially in anti-parasitic immunity. we conducted the phagocytic activity of blood platelets. this experiments were done on 40 patients infected with giardia intestinalis (26), ascaris lumbricoides (8), entamoeba histolytica/entamoeba dispar (6). blood for analysis was collected thrice, before treatment (p1), after two weeks (p2), and after two months treatment with anti-parasitic drugs (p3). control group consisted of 32 healthy p ...	2002	12632920
[protozoa and food hygiene].		2002	12635345
amoebic versus pyogenic liver abscess.	to study the differences between the clinical presentation and complications of amoebic and pyogenic liver abscess. to correlate the diagnostic significance of entamoeba indirect haemagglutination test (e.iha) in establishing the diagnosis of amoebic liver abscess.	2002	12585366
segmentation and tracking of migrating cells in videomicroscopy with parametric active contours: a tool for cell-based drug testing.	this paper presents a segmentation and tracking method for quantitative analysis of cell dynamics from in vitro videomicroscopy data. the method is based on parametric active contours and includes several adaptations that address important difficulties of cellular imaging, particularly the presence of low-contrast boundary deformations known as pseudopods, and the occurence of multiple contacts between cells. first, we use an edge map based on the average intensity dispersion that takes advantag ...	2002	12585703