Publications

geographic diversity among genotypes of entamoeba histolytica field isolates.	it has been known that only 5 to 10% of those infected with entamoeba histolytica develop symptomatic disease. however, the parasite and the host factors that determine the onset of disease remain undetermined. molecular typing by using polymorphic genetic loci has been proven to aid in the close examination of the population structure of e. histolytica field isolates in nature. in the present study, we analyzed the genetic polymorphisms of two noncoding loci (locus 1-2 and locus 5-6) and two pr ...	2003	12904386
interaction of amoebapores and nk-lysin with symmetric phospholipid and asymmetric lipopolysaccharide/phospholipid bilayers.	amoebapores from protozoan parasite entamoeba histolytica and nk-lysin of porcine cytotoxic lymphocytes belong to the same family of saposin-like proteins. in addition to the structural similarity, amoebapores and nk-lysin are both highly effective against prokaryotic and eukaryotic target cells in that they permeabilize the target cell membranes. here, we have investigated in detail the protein/lipid interaction for the three isoforms of amoebapore and nk-lysin. results obtained from electrical ...	2003	12911324
[a diagnostic approach to hepatic abscess].	the non invasive diagnosis of amebic liver abscess allows the use of empirical therapy without the requirement of invasive diagnostic procedures.	2003	15022404
[parasitic diarrhea in children].	in many areas, entamoeba histolytica and entamoeba dispar are found together and their microscopic appearance is identical. biochemical tests which can show cell wall differences are often falsely negative and the only possible way is to treat with metronidazole when amoebiasis is suspected. in case of clinical failure of metronidazole, a bacterial diarrhea is frequently found. giardia is an other protozoa frequently found in stools of children in endemic areas. diarrheas due to giardia are poss ...	2003	15022781
consumption of l-arginine mediated by entamoeba histolytica l-arginase (eharg) inhibits amoebicidal activity and nitric oxide production by activated macrophages.	in this study we discuss the cloning and expression of entamoeba histolytica arginase (eharg), an enzyme that catalyses the hydrolysis of l-arginine to l-ornithine and urea. l-norvaline, a competitive inhibitor of e. histolytica l-arginase, inhibits the growth of the parasite, which suggests that the catabolism of l-arginine mediated by eharg is essential. nitric oxide (no) is an antimicrobial agent that inhibits some key enzymes in the metabolism of entamoeba histolytica. no is synthesized by a ...	2003	15053781
foodborne and waterborne parasites.	more than 72 species of protozoan and helminth parasites can reach humans by food and water, and most of these infections are zoonoses. some parasites show a cosmopolitan distribution, others a more restricted distribution due to their complex life cycles, which need the presence of one or more intermediate hosts. of this large number of pathogens, only toxoplasma gondii can be transmitted to humans by two different ways, i.e., by cysts present in infected meat and by oocysts contaminating food ...	2003	15058817
environmental contamination with protozoan parasite infective stages: biology and risk assessment.	in the present paper some aspects of the biology and various factors influencing the potential for environmental contamination with protozoan parasites infective stages implicated in water and foodborne diseases are described. the major protozoan species that affect humans are entamoeba histolytica, acanthamoeba sp., neagleria sp. giardia intestinalis, cryptosporidium parvum, cyclospora cayetanensis, toxoplasma gondii, isospora/sarcocystis sp. encephalitozoom intestinals and enterocytozoon biene ...	2003	15058818
an anti-inflammatory oligopeptide produced by entamoeba histolytica down-regulates the expression of pro-inflammatory chemokines.	axenically grown entamoeba histolytica produces a pentapeptide (met-gln-cys-asn-ser) with anti-inflammatory properties that, among others, inhibits the in vitro and in vivo locomotion of human monocytes, sparing polymorphonuclear leucocytes from this effect [hence the name originally given. monocyte locomotion inhibitory factor (mlif)]. a synthetic construct of this peptide displays the same effects as the native material. we now added mlif to resting and pma-stimulated cells of a human monocyte ...	2003	15157024
human amoebic hepatic abscess: in situ interactions between trophozoites, macrophages, neutrophils and t cells.	amoebic liver abscesses (ala) are the most frequent and severe extraintestinal clinical presentations of amoebiasis. during the early establishment of amoebae in the liver parenchyma, as well as during the extension of the tissue necrosis, parasites interact with the parenchymal liver cells and, as a consequence of these interactions, hepatocytes can be destroyed and host immune cells can become activated. however, little is known about the nature of these interactions in the liver or about the ...	2003	15157027
using ancestral sequences to uncover potential gene homologues.	gene homologues between distantly related species can be difficult to identify. we test the idea that inferred ancestral sequences could aid in finding gene homologues. ancestral sequences are inferred by aligning gene homologues on a known tree and estimating the most likely amino acid for each position at each node in that tree. blast(r) and hmmer are used separately and together with ancestral sequences to search the genome sequence databases of encephalitozoon cuniculi, entamoeba histolytica ...	2003	15130821
overdiagnosis of amoebiasis in the absence of entamoeba histolytica among patients presenting with diarrhoea in wonji and akaki, ethiopia.	to confirm the high reported incidence of intestinal amoebiasis among study participants at 2 cohort sites in ethiopia where an hiv/aids study is taking place, stool samples of 232 patients with complaints of diarrhoea were examined for the presence of entamoeba histolytica and e. dispar dna between april and december 2001. by microscopy, 91 (39%) of the study participants were reported to harbour entamoeba trophozoites and/or four-nucleated cysts. using specific e. histolytica and e. dispar dna ...	2003	15228248
a virulence attenuated amoebapore-less mutant of entamoeba histolytica and its interaction with host cells.	entamoeba histolytica, the protozoan parasite which causes amoebiasis, is an exclusively human pathogen so developing a vaccine could effectively impact the spread of the disease. recently we developed a genetically modified avirulent strain, termed g3, from the virulent e. histolytica strain hm-1:imss. the new strain lacks the important virulence factor, the amoebapore-a. the objective of our current study was to investigate the avirulence of the attenuated strain as well as to examine the anti ...	2003	14636681
intestinal antilectin immunoglobulin a antibody response and immunity to entamoeba dispar infection following cure of amebic liver abscess.	we followed 93 subjects with amebic liver abscess (ala) and 963 close associate controls at 3-month intervals for 36 months to characterize intestinal and humoral antibody responses to the amebic galactose-inhibitable lectin and to determine whether immunity developed to entamoeba histolytica or entamoeba dispar infection following cure of ala. we found that ala subjects had a higher prevalence and level of intestinal antilectin immunoglobulin a (iga) and serum anti-lc3 (cysteine-rich recombinan ...	2003	14638778
epidemiologic and clinical characteristics of acute diarrhea with emphasis on entamoeba histolytica infections in preschool children in an urban slum of dhaka, bangladesh.	the epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 bangladeshi children (147 boys and 142 girls) 2-5 years old. the use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of entamoeba histolytica to total diarrheal illness in this community setting. the average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average obs ...	2003	14640500
bfa-sensitive and insensitive exocytic pathways in entamoeba histolytica trophozoites: their relationship to pathogenesis.	entamoeba histolytica manifests its pathogenicity through several cellular processes triggered by external stimuli that activate signal transduction pathways. the intense secretory activity resulting from stimulation is not correlated with a typical endoplasmic reticulum (er) or golgi organization, and little is known in this parasite about endocytic/exocytic pathways. the interactions of trophozoites with fibronectin (fn) and cultured mammalian cells, which elicit secretory activities, were cho ...	2003	14641177
short communication: prevalence of entamoeba histolytica and entamoeba dispar in northern ghana.	since the redescription of the potentially invasive entamoeba histolytica, separating it from the morphologically identical non-invasive entamoeba dispar, there is a need for the reassessment of epidemiological data on amoebiasis. in this context we conducted a descriptive survey on the presence of e. histolytica and e. dispar in a rural area in northern ghana. we found a high prevalence (39.8%) of the e. histolytica/e. dispar complex with microscopy, but e. histolytica and e. dispar-specific dn ...	2003	14641852
meeting report: embo workshop "pathogenesis of amoebiasis: from genomics to disease", institut pasteur, paris, may 19-22, 2003.		2003	14658490
evidence for golgi bodies in proposed 'golgi-lacking' lineages.	golgi bodies are nearly ubiquitous in eukaryotic cells. the apparent lack of such structures in certain eukaryotic lineages might be taken to mean that these protists evolved prior to the acquisition of the golgi, and it raises questions of how these organisms function in the absence of this crucial organelle. here, we report gene sequences from five proposed 'golgi-lacking' organisms (giardia intestinalis, spironucleus barkhanus, entamoeba histolytica, naegleria gruberi and mastigamoeba balamut ...	2003	14667372
an epidemiological study of pleuropulmonary paragonimiasis among pupils in the peri-urban zone of kumba town, meme division, cameroon.	paragonimiasis have previously been reported in two zones of the southwest province of cameroon including the kupe mountain and mundani foci. the aim of this study was to investigate the presence and epidemiology of paragonimiasis in the peri-urban zone of kumba, meme division, located about 50 km away from the kupe mountain focus.	2003	14678562
collagen-induced stat family members activation in entamoeba histolytica trophozoites.	the interaction of entamoeba histolytica trophozoites with collagen type i and calcium induces a membrane to nuclei signaling. the transduction pathways involved in such phenomena are still poorly understood. using a combination of immunoprecipitation assays, western immunoblot analysis, electrophoretic mobility shift assays and immunocytochemistry we demonstrate here the expression, tyrosine phosphorylation, nuclear translocation and dna binding of two members of the signal transducers and acti ...	2003	14680700
bifunctional aldehyde/alcohol dehydrogenase (adhe) in chlorophyte algal mitochondria.	protein profiles of mitochondria isolated from the heterotrophic chlorophyte polytomella sp. grown on ethanol at ph 6.0 and ph 3.7 were analyzed by blue native and denaturing polyacrylamide gel electrophoresis. steady-state levels of oxidative phosphorylation complexes were influenced by external ph. levels of an abundant, soluble, mitochondrial protein of 85 kda and its corresponding mrna increased at ph 6.0 relative to ph 3.7. n-terminal and internal sequencing of the 85 kda mitochondrial prot ...	2003	14756315
identification and characterization of a cyclooxygenase-like enzyme from entamoeba histolytica.	the intestinal protozoan parasite entamoeba histolytica remains a significant cause of morbidity and mortality worldwide. however, almost nothing is known about the molecules secreted by the parasite that modulate host immune responses or epithelial barrier function in the colon. herein, we describe the isolation and characterization of a cyclooxygenase (cox)-like enzyme in e. histolytica that is responsible for the biosynthesis of prostaglandin (pg)e2. pge2 produced by ameba was constitutive bu ...	2003	14585927
detection and identification of entamoeba species in stool samples by a reverse line hybridization assay.	classically, detection of entamoeba histolytica is performed by microscopic examination for characteristic cysts and/or trophozoites in fecal preparations. differentiation of e. histolytica cysts and those of nonpathogenic amoebic species is made on the basis of the appearance and the size of the cysts. however, by classical means objective tools for confirmation and quality control do not exist. therefore, a reverse line blot hybridization assay was developed to detect a variety of entamoeba sp ...	2003	14605136
mitochondrial remnant organelles of giardia function in iron-sulphur protein maturation.	giardia intestinalis (syn. lamblia) is one of the most widespread intestinal protozoan pathogens worldwide, causing hundreds of thousands of cases of diarrhoea each year. giardia is a member of the diplomonads, often described as an ancient protist group whose primitive nature is suggested by the lack of typical eukaryotic organelles (for example, mitochondria, peroxisomes), the presence of a poorly developed endomembrane system and by their early branching in a number of gene phylogenies. the d ...	2003	14614504
the cell cycle of entamoeba histolytica.	entamoeba histolytica, is a microaerophilic protist, which causes amoebic dysentery in humans. this unicellular organism proliferates in the human intestine as the motile trophozoite and survives the hostile environment outside the human host as the dormant quadri-nucleate cyst. lack of organelles--such as mitochondria and golgi bodies--and an unequal mode of cell division, led to the popular belief, that this organism preceded other eukaryotes during evolution. however, data from several labora ...	2003	14619972
intestinal parasites in children, in highly deprived areas in the border region of chiapas, mexico.	to assess the prevalence of intestinal parasitic infections among children in highly deprived areas, and its possible association with demographic and socioeconomic indicators.	2003	14628618
purification of entamoeba histolytica dna containing organelles (ekhos): a further characterization.		2003	14736228
intestinal parasites among african refugees resettled in massachusetts and the impact of an overseas pre-departure treatment program.	this study analyzed the prevalence of intestinal parasitoses diagnosed shortly after arrival in the united states among african refugees before and after implementation of an overseas program of empirical treatment with albendazole. variables included results of microscopy of a single stool specimen, age, sex, ethnicity, departure origin, and receipt of albendazole. of 1,254 refugees, 56% had intestinal parasites. fourteen percent had helminths, and 2% had multiple helminths. in addition, 52% ha ...	2003	14740885
entamoeba histolytica: an update.	over the past decade, since it was formally recognized that entamoeba histolytica and entamoeba dispar were two distinct species, studies in this field have made dramatic in-roads into the understanding of e. histolytica and the pathogenesis of invasive amoebiasis. over the same period it has also become clear that the true incidence of e. histolytica infection, particularly in vulnerable populations such as low socioeconomic children, is exceedingly high. understanding the epidemiology, pathoph ...	2003	14502002
[nine-year progression of amoebal rectitis].		2003	14506451
regulatory effects of il-12 and il-18 on onchocerca volvulus- and entamoeba histolytica-specific cellular reactivity and cytokine profiles.	in the present study, the cytokines interleukin (il)-12 and il-18 were evaluated for their capacity to modulate and to re-direct in vitro parasite antigen-specific cellular responsiveness in patients exposed to onchocerca volvulus and entamoeba histolytica infection. we found that il-18 was highly capable of reducing parasite antigen-induced il-10 production by pbmc. in contrast, addition or neutralization of il-12, also in combination with il-18 and the interferon-gamma-inducible chemokine ip-1 ...	2003	14507330
oral cavity as a potential source of infections in recipients with diabetes mellitus.	our previous observations showed alterations of oral cavity status among hemodialyzed patients and kidney allograft recipients as well as differences in the prevalence and composition of microorganisms occurring in the mouths of patients. in the present work, we analysed the results of oral cavity examinations, the identification of microorganisms, and the assessment of their importance to kidney allograft recipients or hemodialyzed patients with diabetes mellitus, in comparison with nondiabetic ...	2003	14529890
etiology of acute diarrhea in adults in southwestern nigeria.	stool specimens from 113 adult outpatients with diarrhea in southwestern nigeria and 63 controls were examined for bacterial and parasitic enteric pathogens. enterohemorrhagic escherichia coli (ehec) (p < 0.02), enteroaggregative e. coli (eaec) (p < 0.02), and entamoeba histolytica (p < 0.0002) were significantly associated with diarrhea. salmonella, shigella, nontoxigenic vibrio cholerae, other categories of diarrheagenic e. coli, as well as a variety of helminths were recovered more frequently ...	2003	14532177
longitudinal study of intestinal entamoeba histolytica infections in asymptomatic adult carriers.	to gain insight into the dynamics of intestinal entamoeba histolytica infection, a longitudinal study was performed over an observation period of 15 months with a group of 383 randomly selected adult individuals (mean age, 38.5 years) living in an area of amebiasis endemicity in central vietnam. ameba infection was diagnosed by using species-specific pcr and dna extracted directly from fecal samples. the results indicated an e. histolytica prevalence of 11.2% and an annual new infection rate of ...	2003	14532214
effective human defense against e. histolytica: high amoebicidal activity of lymphocytes and monocytes in amoebic liver abscess patients until 3 months follow-up.	adherence of pathogenic entamoeba histolytica trophozoites mediated by gal/galnac lectin is a prerequisite for killing naïve t cells and monocytes but the activated t cells and monocyte derived macrophages (mdms) not only resist the attack but can kill the parasite. in the present study, we have analysed the adherence and cytotoxicity of the immunecompetent cells from patients of amoebic liver abscess at the time of their diagnosis and after 3 months to elucidate the development of cell mediated ...	2003	14550474
nitric oxide synthase in entamoeba histolytica: its effect on rat aortic rings.	nadph-diaphorase activity has been considered as a nitric oxide synthase (nos) marker. therefore, the presence of nadph-d activity in entamoeba histolytica suggests that they have nos activity. the aim of this work was to provide support for this contention. the amebic culture medium or amebic purified proteins induced relaxation of endothelium-denuded rat aortic rings pre-contracted with phenylephrine (10(-6) m), which was inhibited when the amebas were incubated with ng-monomethyl-l-arginine o ...	2003	14552855
laboratory diagnosis of amebiasis.	the detection of entamoeba histolytica, the causative agent of amebiasis, is an important goal of the clinical microbiology laboratory. to assess the scope of e. histolytica infection, it is necessary to utilize accurate diagnostic tools. as more is discovered about the molecular and cell biology of e. histolytica, there is great potential for further understanding the pathogenesis of amebiasis. molecular biology-based diagnosis may become the technique of choice in the future because establishm ...	2003	14557296
glycogen phosphorylase sequences from the amitochondriate protists, trichomonas vaginalis, mastigamoeba balamuthi, entamoeba histolytica and giardia intestinalis.	glycogen phosphorylase genes or messages from four amitochondriate eukaryotes, trichomonas vaginalis, mastigamoeba balamuthi, entamoeba histolytica (two genes) and giardia intestinalis, have been isolated and sequenced. the sequences of the amitochondriate protist enzymes appear to share a most recent common ancestor. the clade containing these sequences is closest to that of another protist, the slime mold (dictyostelium discoideum), and is more closely related to fungal and plant phosphorylase ...	2003	14563176
intestinal parasitic infections in man: a review.	intestinal parasites of importance to man are enterobius vermicularis, the soil-transmitted helminthes (sth)--ascaris lumbricoides tricburis trichiura, bookworms (necator americans/ancylostoma duodenale) and strongyloides stercoralis and the protozoa entamoeba histolytica and giardia duodenalis. other protozoa such as cryptosporidium sp. and isopora sp. are becoming important in causing prolonged diarrhea in immunocompromised patients. it is estimated that almost 1 billion, 500 million and 900 m ...	2003	14569755
purification and biochemical characterization of a soluble alpha-glucosidase from the parasite entamoeba histolytica.	a soluble alpha-glucosidase presumably involved in the general carbohydrate metabolism was purified from e. histolytica trophozoites by a three-step procedure consisting of ion exchange, size exclusion and adsorption chromatographies in columns of mono q, sepharose cl-6b and hydroxyapatite, respectively. after the last step, the enzyme was enriched about 673-fold over the starting material with a yield of 18%. sds-page revealed the presence in the purified preparations of two polypeptides of com ...	2003	14574111
[prevalence of microsporidia and other intestinal parasites in patients with hiv infection, bogota, 2001].	opportunistic intestinal parasites are a common cause of diarrhea in hiv-infected patients. to determine the prevalence of microsporidia and other opportunistic parasites infecting hiv patients in bogotá, colombia, 115 patients were examined for these infections during the year 2001. the institution and the sample percent from each are as follows: santa clara hospital, 33.0%; san pedro claver, 20.0%; simón bolívar hospital, 14.8%; san josé hospital, 13.9%; central de la policía hospital, 6.1%; c ...	2003	14582330
salpingitis due to entamoeba histolytica.	we describe the pathology of a unique case of fallopian tube amebiasis, associated with hydrosalpinx, in a 21-year-old woman. she complained of lower abdominal pain, had a foul-smelling green vaginal discharge and fever during one week. there was a discrete increase in body temperature and a painful abdominal palpation at the lower right side, with signs of local peritoneal irritation. pathological examination showed a marked dilatation of the fallopian tube and hydrosalpinx. microscopic examina ...	2003	11980611
parasitic infections among karen in kanchanaburi province, western thailand.	the purpose of this study was to determine the rate of intestinal parasitic and malarial infections during a period of low infection among the residents of remote karen villages in thailand. fifty-five males and 64 females, aged 6 months to 70 years, were examined for malaria by thick blood smears using the giemsa staining technique. of the 119 subjects, 4 (3.36%) showed positive for malaria with vivax gametocytes. results suggested that mass screening was not an effective way for diagnosing mal ...	2003	19230576
a spectrum of pathogenic and non-pathogenic intestinal parasites in pre-employment medical check-up for workers and their families.	stool analysis plays an important role in pre-employment tests for the screening of intestinal parasites in new workers.	2003	23011980
molecular cloning and characterization of a protein farnesyltransferase from the enteric protozoan parasite entamoeba histolytica.	genes encoding alpha- and beta-subunits of a putative protein farnesyltransferase (ft) from the enteric protozoan parasite entamoeba histolytica were obtained and their biochemical properties were characterized. deduced amino acid sequences of the alpha- and beta-subunit of e. histolytica ft (ehft) were 298- and 375-residues long with a molecular mass of 35.6 and 42.6 kda, and a pi of 5.43 and 5.65, respectively. they showed 24% to 36% identity to and shared common signature domains and repeats ...	2004	14583615
prevention of intestinal amebiasis by vaccination with the entamoeba histolytica gal/galnac lectin.	prevention of intestinal infection by entamoeba histolytica would block both invasive disease and parasite transmission. the amebic gal/galnac lectin mediates parasite adherence to the colonic surface and fecal anti-lectin iga is associated with protection from intestinal reinfection in children. we tested if vaccination with the e. histolytica gal/galnac lectin could prevent cecal infection in a c3h mouse model of amebic colitis. two trials using native lectin purified from the parasite and two ...	2004	14741152
expression of amoebapores is required for full expression of entamoeba histolytica virulence in amebic liver abscess but is not necessary for the induction of inflammation or tissue damage in amebic colitis.	entamoeba histolytica trophozoites produce amoebapores, a family of small amphipathic peptides capable of insertion into bacterial or eukaryotic membranes and causing cellular lysis. recently, e. histolytica trophozoites that are totally deficient in the production of amoebapore-a were created through a gene silencing mechanism (r. bracha, y. nuchamowitz, and d. mirelman, eukaryot. cell 2:295-305, 2003). here we tested the virulence of amoebapore a(-) trophozoites in models of the two major form ...	2004	14742508
influence of human leukocyte antigen class ii alleles on susceptibility to entamoeba histolytica infection in bangladeshi children.	the association of antibody responses with both innate and acquired immunity to amebiasis indicate that cd4+ t cells play a role in protection against entamoeba histolytica infection. to test this hypothesis, we compared the genotype frequencies of human leukocyte antigen (hla) class ii alleles in a cohort of bangladeshi children intensively monitored for e. histolytica infection for a 3-year period.	2004	14745711
[indigenous amebic liver abscess. presentation of a case].		2004	14746764
gastrointestinal parasite infestation.	twenty-five percent of the world's population could be suffering parasitic infestation. highest prevalence is in underdeveloped agricultural and rural areas in the tropical and subtropical regions. in some areas incidence may reach 90% of the population. in contrast, some major economic projects intended to promote local development have, paradoxically, caused parasitic proliferation, e.g. bilharziasis in egypt and sudan and chagas disease in brazil. the commonest cosmopolitan gastrointestinal p ...	2004	14749961
regulation of toll-like receptor-2 expression by the gal-lectin of entamoeba histolytica.	the gal/galnac lectin (gal-lectin) of entamoeba histolytica is a surface molecule involved in parasite adherence to host cells and is the most promising subunit vaccine candidate against amoebiasis. as macrophages are the major effector cells in host defense against amoebas, we studied the molecular mechanisms by which gal-lectin activates macrophage. microarray analysis showed that gal-lectin up-regulated mrnas of several cytokines and receptor genes involved in proinflammatory responses. the m ...	2004	14630697
an intestinal parasitic protist, entamoeba histolytica, possesses a non-redundant nitrogen fixation-like system for iron-sulfur cluster assembly under anaerobic conditions.	we have characterized the iron-sulfur (fe-s) cluster formation in an anaerobic amitochondrial protozoan parasite, entamoeba histolytica, in which fe-s proteins play an important role in energy metabolism and electron transfer. a genomewide search showed that e. histolytica apparently possesses a simplified and non-redundant nif (nitrogen fixation)-like system for the fe-s cluster formation, composed of only a catalytic component, nifs, and a scaffold component, nifu. amino acid alignment and phy ...	2004	14757765
intestinal parasites among presumably healthy individuals in lebanon.	to determine the prevalence period of intestinal parasites among presumably healthy subjects in lebanon.	2004	14758375
effects of cd(+2), cu(+2), ba(+2) and co(+2) ions on entamoeba histolytica cysts.	the effects of cobalt, copper, cadmium and barium ions on the cysts of entamoeba histolytica (e. histolytica), an amebic dysentery agent, cultured in robinson medium were investigated.	2004	14760778
parasitic diseases of the heart.	the following chapter is one of a series of chapters in the volume entitled infections of the myocardium appearing in frontiers in bioscience. the full table of contents can be found at http://www.bioscience.org/current/special/tanowitz.htm. in this chapter, we review several parasitic infections involving the myocardium and pericardium. the most widely studied parasitic infection affecting the heart is chagas' disease or american trypanosomiasis. in this chapter we describe issues relating to c ...	2004	14766402
an entamoeba histolytica line/sine pair inserts at common target sites cleaved by the restriction enzyme-like line-encoded endonuclease.	the non-long-terminal-repeat (non-ltr) retrotransposons (also called long interspersed repetitive elements [lines]) are among the oldest retroelements. here we describe the properties of such an element from a primitive protozoan parasite, entamoeba histolytica, that infects the human gut. this 4.8-kb element, called ehline1, is present in about 140 copies dispersed throughout the genome. the element belongs to the r4 clade of non-ltr elements. it has a centrally located reverse transcriptase do ...	2004	14871947
effects of bisphosphonates on the growth of entamoeba histolytica and plasmodium species in vitro and in vivo.	the effects of a series of 102 bisphosphonates on the inhibition of growth of entamoeba histolytica and plasmodium falciparum in vitro have been determined, and selected compounds were further investigated for their in vivo activity. forty-seven compounds tested were active (ic(50) < 200 microm) versus e. histolytica growth in vitro. the most active compounds (ic(50) approximately 4-9 microm) were nitrogen-containing bisphosphonates with relatively large aromatic side chains. simple n-alkyl-1-hy ...	2004	14695831
molecular cloning, expression and characterization of a serine proteinase inhibitor gene from entamoeba histolytica.	serine proteinase inhibitors (serpins) are irreversible suicide inhibitors of proteinases that regulate a wide range of biological processes, including pathogen evasion of the host defence system. we report the cloning and characterization of a gene encoding a serpin from the protozoan parasite entamoeba histolytica (ehserp) that may function in this manner. the protein encoded by ehserp contains 371 amino acids with a predicted mass of 42.6 kda. antibodies to a 42 kda recombinant ehserp react s ...	2004	14698428
genes induced by a high-oxygen environment in entamoeba histolytica.	entamoeba histolytica, although a microaerophilic protozoan parasite, encounters a high-oxygen environment, during invasive amoebiasis. the parasite requires specific regulation of certain proteins to maintain its physiological functions to survive in the more oxygenated condition. our endeavor was to know how does amoeba adapt itself in a high-oxygen environment. reactive oxygen species (ros) was found to accumulate in an increasing concentration within the stressed trophozoites in a time-depen ...	2004	14698431
parasite and host contributions to the pathogenesis of amebic colitis.		2004	14700586
identification and characterization of ehcabp2. a second member of the calcium-binding protein family of the protozoan parasite entamoeba histolytica.	entamoeba histolytica, an early branching eukaryote, is the etiologic agent of amebiasis. calcium plays a pivotal role in the pathogenesis of amebiasis by modulating the cytopathic properties of the parasite. however, the mechanistic role of ca(2+) and calcium-binding proteins in the pathogenesis of e. histolytica remains poorly understood. we had previously characterized a novel calcium-binding protein (ehcabp1) from e. histolytica. here, we report the identification and partial characterizatio ...	2004	14711825
bacterial expression of a human monoclonal antibody-alkaline phosphatase conjugate specific for entamoeba histolytica.	we previously produced human monoclonal antibody fab fragments specific to entamoeba histolytica in escherichia coli. in order to use these fab fragments for diagnostic purposes, an expression vector to produce a fusion protein of fab and alkaline phosphatase (phoa) in e. coli was designed and constructed. the e. coli phoa gene was fused to the 3' terminus of the gene encoding the heavy-chain fd region. the kappa and fd genes from a previously prepared antibody clone, cp33, which is specific for ...	2004	14715571
characterization of cytosine methylated regions and 5-cytosine dna methyltransferase (ehmeth) in the protozoan parasite entamoeba histolytica.	the dna methylation status of the protozoan parasite entamoeba histolytica was heretofore unknown. in the present study, we developed a new technique, based on the affinity of methylated dna to 5-methylcytosine antibodies, to identify methylated dna in this parasite. ribosomal dna and ribosomal dna circles were isolated by this method and we confirmed the validity of our approach by sodium bisulfite sequencing. we also report the identification and the characterization of a gene, ehmeth, encodin ...	2004	14715927
[the 'bull's eye' pattern in hepatic tomography].	invasive fungal infections are more commonly found in patients who develop neutropenia after chemotherapy. a 4-year-old girl with diagnosis of acute lymphoid leukemia developed febrile neutropenia after chemotherapy. broad spectrum antibiotics and antimycotic therapy were initiated. candida albicans was isolated and entamoeba histolytica was observed in stool examination. chronic disseminated candidiasis had developed and was treated with amphotericin b, initially, and fluconazol. computed tomog ...	2004	15239596
detection and genotyping of entamoeba histolytica, entamoeba dispar, giardia lamblia, and cryptosporidium parvum by oligonucleotide microarray.	entamoeba histolytica, giardia lamblia, and cryptosporidium parvum are the most frequently identified protozoan parasites causing waterborne disease outbreaks. the morbidity and mortality associated with these intestinal parasitic infections warrant the development of rapid and accurate detection and genotyping methods to aid public health efforts aimed at preventing and controlling outbreaks. in this study, we describe the development of an oligonucleotide microarray capable of detecting and di ...	2004	15243091
identification of genomic responses to collagen binding by trophozoites of entamoeba histolytica.	attachment of entamoeba histolytica trophozoites to collagen is a known stimulus for parasite activation, leading to subsequent tissue destruction and invasion. to identify cellular mechanisms of trophozoite activation, we assessed global variations in gene expression during collagen interaction with e. histolytica. a shotgun dna microarray was constructed by use of 9600 random inserts from an e. histolytica genomic dna library. through differential hybridization, key differences between gene ex ...	2004	15243916
pyogenic and amebic liver abscesses.	pyogenic and amebic liver abscesses are the two most common hepatic abscesses. amebic abscesses are more common in areas where entamoeba histolytica is endemic, whereas pyogenic abscesses are more common in developed countries. pyogenic abscess severity is dependent on the bacterial source and the underlying condition of the patient. amebic liver abscess is more prevalent in individuals with suppressed cell-mediated immunity, men, and younger people. the right lobe of the liver is the most likel ...	2004	15245694
inhibition of gene expression with double strand rna interference in entamoeba histolytica.	in order to inhibit gene expression in entamoeba histolytica, we have developed a method based on expressing double strand rna interference constructs in stable transformants. the 5' end of eh dia was cloned head to head with an intervening non-specific stuffer fragment in the e. histolytica expression vector pjst4. this construct was transformed in e. histolytica hm1:imss trophozoites and stable transformants were selected with 20microg/ml g418. our results show that expression of eh dia was co ...	2004	15249205
histopathology of cutaneous amebiasis.	cutaneous amebiasis (ca) is the manifestation in the skin and underlying soft tissues of the pathogenic properties of entamoeba histolytica, which may be the only expression of the infection or may be associated with disease in other organs. so far, there have been only isolated case reports on this disease. we herein report the histopathologic findings on a series of seven cases, six adults and one child, of ca. the most common findings include ulcers, areas of necrosis, mixed inflammatory infi ...	2004	15249857
calcium binding protein 1 of the protozoan parasite entamoeba histolytica interacts with actin and is involved in cytoskeleton dynamics.	blocking expression of ehcabp1, a calmodulin-like, four ef-hand protein from the protozoan parasite entamoeba histolytica, resulted in inhibition of cellular proliferation. in this paper we report that ehcabp1 is involved in dynamic changes of the actin cytoskeleton. both endocytosis and phagocytosis were severely impaired in cells where ehcabp1 expression was blocked by inducible expression of the antisense rna. in wild-type cells both actin and ehcabp1 were found to co-localize in phagocytic c ...	2004	15252130
multiple parasite infections and their relationship to self-reported morbidity in a community of rural côte d'ivoire.	concomitant parasitic infections are common in the developing world, yet most studies focus on a single parasite in a narrow age group. we investigated the extent of polyparasitism and parasite associations, and related these findings to self-reported morbidity.	2004	15256525
enteric infection in relapse of inflammatory bowel disease: importance of microbiological examination of stool.	previous reports have suggested that diarrhoeal relapses of inflammatory bowel disease (ibd) may be associated or confused with enteric infection, and that treatment of such infections with appropriate antibiotics may be beneficial. to re-evaluate the suggestion that enteric infection is rare and microbiological testing of stool not routinely necessary in patients presenting with relapse of ibd, we have reviewed the incidence of concurrent infection in patients presenting in relapse over a recen ...	2004	15256979
mitosomes of entamoeba histolytica are abundant mitochondrion-related remnant organelles that lack a detectable organellar genome.	the existence of mitochondrion-related relict organelles (mitosomes) in the amitochondrial human pathogen entamoeba histolytica and the detection of extranuclear dna-containing cytoplasmic structures (ehkos) has led to the suggestion that a remnant genome from the original mitochondrial endosymbiont might have been retained in this organism. this study reports on the mutually exclusive distribution of cpn60 and extranuclear dna in e. histolytica and on the distribution of cpn60-containing mitoso ...	2004	15133087
expression in fibroblasts and in live animals of entamoeba histolytica polypeptides ehcp112 and ehadh112.	ehcpadh is an immunogenic, heterodimeric protein that is formed by ehcp112 (cysteine protease) and ehadh112 (adhesin), polypeptides involved in entamoeba histolytica's cytopathic effect, target-cell adherence and phagocytosis. the ehcpadh complex is located in the plasma membrane and cytoplasmic vacuoles. here, the independent expression of ehcp112 and ehadh112 in fibroblasts and hamsters was analysed. also investigated was the immunological response in animals independently inoculated with plas ...	2004	15133088
microbial contamination of drinking water and disease outcomes in developing regions.	drinking water is a major source of microbial pathogens in developing regions, although poor sanitation and food sources are integral to enteric pathogen exposure. gastrointestinal disease outcomes are also more severe, due to under-nutrition and lack of intervention strategies in these regions. poor water quality, sanitation and hygiene account for some 1.7 million deaths a year world-wide (3.1% of all deaths and 3.7% of all daly's), mainly through infectious diarrhoea. nine out of 10 such deat ...	2004	15138046
contact of entamoeba histolytica with baby hamster kidney-21 (bhk-21) cell line on cysteine proteinase activity.	entamoeba histolytica, the causative agent of amoebiasis and amoebic liver abscess, lyses host cells by direct contact using surface lectins and releases cysteine proteinase (cp). virulence of e. histolytica is directly related to activity of its cp. the relationship of cp activity and cytotoxicity has not been established. the present study was carried out to explore the events following contact of e. histolytica with target cells.	2004	15147121
entamoeba histolytica alcohol dehydrogenase 2 (ehadh2) as a target for anti-amoebic agents.	the current use of metronidazole as an anti-amoebic agent causes significant side-effects. the purpose of this study was to identify alternative compounds with which to treat amoebiasis.	2004	15150165
proteinase inhibitors tpck and tlck prevent entamoeba histolytica induced disturbance of tight junctions and microvilli in enteric cell layers in vitro.	tight junctions and microvilli constitute an anti-invasive barrier at the luminal side of enteric cell layers. both subcellular structures are disrupted following adhesion of entamoeba histolytica trophozoites to enteric cell layers in vitro. it was our aim to analyse the molecular mechanism underlying this disruption. therefore, we cocultured enteric t84 cell layers established on filter inserts with e. histolytica trophozoites and tested various modulators of enteric molecules, involved in the ...	2004	15157761
amebiasis and comparison of microscopy to elisa technique in detection of entamoeba histolytica and entamoeba dispar.	the analysis of records of amoebal infection in various hospitals in kilimanjaro indicated frequent occurrence of amebiasis. the population over the age of five years had higher rate of amoebal infection compared to less than that of a five-year-old population; however, both age groups had similar patterns of amebiasis during january 1999 to june 2001. to investigate misdiagnosis of amebiasis, 226 patients (passive cases) in three hospitals and 616 individuals (active cases) from three different ...	2004	15160983
recognition of entamoeba histolytica 115-kda surface protein by human secretory immunoglobulin a antibodies from asymptomatic carriers.	entamoeba histolytica is a protozoan parasite that can invade the intestinal mucosa. infection induces production of secretory immunoglobulin a (siga) antibodies that can diminish the adhesion between e. histolytica trophozoites and epithelial cells in vitro and reduce the rate of new infections in children. siga antibodies produced by asymptomatic cyst carriers could play a protective role against the damage caused by e. histolytica. to identify membrane antigens capable of inducing siga respon ...	2004	15165062
entamoeba histolytica: induction of cyclooxygenase-2 expression during amoebic liver abscess formation in hamsters (mesocricetus auratus).	experimental amoebic liver abscess in hamsters curses with an increase in both, systemic levels of prostaglandin e2 (pge(2)) and local cyclooxygenase activity in liver microsomes. the cellular source of pge(2) and the isoform of cyclooxygenase responsible are not completely evidenced. cyclooxygenase-2 (cox-2) protein and gene expression were demonstrated on macrophages and polymorphonuclear cells as a result of entamoeba histolytica infection in hamsters at 2, 4, and 7 days postinfection by immu ...	2004	15172219
infection status of intestinal parasites in children living in residential institutions in metro manila, the philippines.	a small scale survey was performed to know the infection status of intestinal parasite in children of the residential institutions and street communities in metro manila, philippines. a total of 284 stool samples from 11 institutions and 3 street communities was examined by the formalin-ether concentration method. the scotch tape anal swab was adapted to 121 children to investigate the infection status of enterovius vermicularis. it was found out that 62.0% of the children examined were positive ...	2004	15181346
sequence divergence of entamoeba histolytica tubulin is responsible for its altered tertiary structure.	atypical microtubular structures of the protozoan parasite entamoeba histolytica (eh) have been attributed to amino acid sequence divergence of eh tubulin. to investigate if this sequence divergence leads to significant differences in the tertiary structure of the eh alphabeta-tubulin heterodimer, we have modeled alphabeta-tubulin heterodimer of eh based on the crystal structure of mammalian tubulin. the predicted 3d homology model exhibits an overall resemblance with the known crystal structure ...	2004	15184082
entamoeba histolytica gal/galnac lectin depletes antioxidant defences of target epithelial cells.	among the variety of virulence factors of entamoeba histolytica, an adherence lectin (gal/galnac, 260 kda) is known to mediate colonization and subsequent host responses. gal/galnac lectin is universally recognized by the immune sera of patients with amoebic liver abscess. it plays a crucial role in cytolysis and phagocytosis of human and rat colonic mucin glycoproteins. the objective of the present study was to elucidate the role of antioxidants in e. histolytica gal/galnac lectin-induced signa ...	2004	15206463
a single step duplex pcr to distinguish entamoeba histolytica from entamoeba dispar.	in this study, a single-step duplex polymerase chain reaction procedure was developed for rapid, specific and sensitive identification of entamoeba histolytica and for its diagnostic differentiation from e. dispar. specific oligonucleotide primers were combined for the amplification of a cysteine proteinase 5 gene target sequence of 242 bp, present only in e. histolytica. additionally, another oligonucleotide primer pair for both the e. histolytica and e. dispar actin gene target of 300 bp was d ...	2004	15206464
molecular and biochemical characterization of d-phosphoglycerate dehydrogenase from entamoeba histolytica. a unique enteric protozoan parasite that possesses both phosphorylated and nonphosphorylated serine metabolic pathways.	a putative phosphoglycerate dehydrogenase (pgdh), which catalyzes the oxidation of d-phosphoglycerate to 3-phosphohydroxypyruvate in the so-called phosphorylated serine metabolic pathway, from the enteric protozoan parasite entamoeba histolytica was characterized. the e. histolytica pgdh gene (ehpgdh) encodes a protein of 299 amino acids with a calculated molecular mass of 33.5 kda and an isoelectric point of 8.11. ehpgdh showed high homology to pgdh from bacteroides and another enteric protozoa ...	2004	15206932
entamoeba histolytica: ultrastructure of trophozoites recovered from experimental liver lesions.	ultrastructural studies on entamoeba histolytica have been carried out mostly with trophozoites cultured for many years. under these conditions, the availability of nutrients and the absence of environmental stimuli may switch off some phenotypic characteristics of the parasite. as a result, virulence of e. histolytica diminishes with prolonged culture passages, and the ability to form cysts disappears in axenically maintained trophozoites. the present analysis by transmission electron microscop ...	2004	15208036
identification of the entamoeba histolytica galactose-inhibitable lectin epitopes recognized by human immunoglobulin a antibodies following cure of amebic liver abscess.	immunity to entamoeba species intestinal infection is associated with the presence of intestinal iga antibodies against the parasite's galactose-inhibitable adherence lectin. we determined the epitope specificity of serum and intestinal antilectin iga antibodies by enzyme-linked immunosorbent assay using overlapping fragments of a recombinant portion of the lectin heavy subunit, designated lc3. these findings were correlated with the effects of epitope-specific murine antilectin immunoglobulin a ...	2004	15213142
enteropathogens associated with cases of gastroenteritis in a rural population in jordan.	stool specimens were collected from 180 patients belonging to a population of recently settled bedouins in jordan who presented with acute or persistent diarrhoea and other symptoms, and from 100 non-diarrhoeal controls. all samples were examined for parasites and bacterial pathogens by culture and pcr. bacterial isolates were tested for their susceptibility to common antimicrobial agents. pathogens and potential enteropathogens were identified from 140 (77.8%) of the patients, with more than on ...	2004	15214876
inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters.	we have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (aealah). in hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. focal liver ischemia, always present in control aealah wi ...	2004	15215052
resistance of entamoeba histolytica to the cysteine proteinase inhibitor e64 is associated with secretion of pro-enzymes and reduced pathogenicity.	cysteine proteinases (cps) have been considered suitable targets for the development of antiparasitic drugs. to assess the importance of cps for the growth and pathogenicity of the protozoan parasite entamoeba histolytica we have cultured amoebae in the presence of various cysteine proteinase inhibitors (cpis). it was found that broad range cpis, which are membrane permeable and rapidly enter the cell, are highly toxic at micromolar concentrations, and all attempts to generate e. histolytica mut ...	2004	15215238
overexpression of myosin ib in living entamoeba histolytica enhances cytoplasm viscosity and reduces phagocytosis.	the human parasite entamoeba histolytica is an ancient protozoan that expresses only one unconventional myosin, which has homology with myosin ib from other amoebae. myosin ib is involved in phagocytosis of human cells by e. histolytica. in this work, we developed a microrheological technique, analysing magnetic phagosomes, which allowed us to probe the density of the f-actin network in living cells. using this technique, we showed that overexpression of myosin ib led to an increase in cytoplasm ...	2004	15226399
protozoal infections in the developmentally disabled: often overlooked cause of rectal digging and fecal smearing.		2004	15226486
parasite-specific antibody and cytokine profiles in newborns from plasmodium falciparum and entamoeba histolytica/dispar-infected mothers.	passage of parasites and their antigens across the placenta occurs with metazoan as well as protozoan parasites, and this study addressed to which extent exposure to and infection of mothers with plasmodium spp. and entamoeba histolytica/dispar has sensitized their offspring for parasite-specific immune responses. while at delivery none of the mothers presented with an acute malaria attack, 42% were seropositive for p. falciparum. in half of the mothers cysts of e. histolytica/dispar were detect ...	2004	15059189
entamoeba histolytica trophozoites transfer lipophosphopeptidoglycans to enteric cell layers.	transfer of antigens frequently follows adhesion of protozoan parasites to host cells. we were interested in such transfer from the entamoeba surface to enterocytes following adhesion of trophozoites. therefore, cocultures of enterocytes in vitro and ex vivo with entamoeba histolytica (strain hm-1:imss) or entamoeba dispar (strain saw760) trophozoites were processed for immunocytochemistry. the eh5 monoclonal antibody against amoebic proteophosphoglycans marked a dotted pattern on the apical sid ...	2004	15064119
accurate diagnosis is essential for amebiasis.		2004	15069733
indirect determination of nitric oxide production by reduction of nitrate with a freeze-thawing-resistant nitrate reductase from escherichia coli mc1061.	preparation of a nitrate reductase lysate of escherichia coli mc1061 to measure nitrate and nitrite in biologic fluids is described. to obtain the crude bacterial lysate containing nitrate reductase activity, e. coli mc1061 was subjected to 16-20 freeze-thawing cycles, from -70 to 60 degrees c, until nitrite reductase activity was < or = 25%. nitrate reductase activity was detected mainly in the crude preparation. to validate the nitrate reduction procedure, standard nitrate solutions (1.6-100 m ...	2004	15081902
common intestinal parasites.	intestinal parasites cause significant morbidity and mortality. diseases caused by enterobius vermicularis, giardia lamblia, ancylostoma duodenale, necator americanus, and entamoeba histolytica occur in the united states. e. vermicularis, or pinworm, causes irritation and sleep disturbances. diagnosis can be made using the "cellophane tape test." treatment includes mebendazole and household sanitation. giardia causes nausea, vomiting, malabsorption, diarrhea, and weight loss. stool ova and paras ...	2004	15023017
diabetes and amoebiasis: a high risk encounter.	amoebiasis is the second most common parasitic disease worldwide. it occurs mainly in developing countries. a high percentage of people in countries where it is endemic are asymptomatic carriers. it results in severe disease that can be fatal in rare cases. diabetics are at increased risk of exposure as travel to countries where it is endemic becomes more frequent, as indicated by the present case. this patient suffered from amoebiasis that produced an amoeboma which is most rare in cases of col ...	2004	15029104
the iron-sulfur cluster assembly genes iscs and iscu of entamoeba histolytica were acquired by horizontal gene transfer.	iron-sulfur (fes) proteins are present in all living organisms and play important roles in electron transport and metalloenzyme catalysis. the maturation of fes proteins in eukaryotes is an essential function of mitochondria, but little is known about this process in amitochondriate eukaryotes. here we report on the identification and analysis of two genes encoding critical fes cluster (isc) biosynthetic proteins from the amitochondriate human pathogen entamoeba histolytica.	2004	15040816