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communicable diseases in the immigrant population attended to in a tropical medicine unit: epidemiological aspects and public health issues.for geographical and historical reasons, spain is receiving an increasing number of immigrants. the aim of this study was to evaluate some epidemiological aspects and the main public health issues of communicable diseases in barcelona's immigrant population. from 2001 to 2004, a population of immigrants from tropical, subtropical regions and eastern europe was attended to in our centre. each patient was offered a complete screening for tropical and common diseases. the prevalence and demographic ...200818342267
effect of iron on adherence and cytotoxicity of entamoeba histolytica to cho cell monolayers.iron is an essential element for almost all living organisms. the possible role of iron for growth, adherence and cytotoxicity of entamoeba histolytica was evaluated in this study. the absence of iron from tyi-s-33 medium stopped amebic growth in vitro. however, iron concentrations in the culture media of 21.4-285.6 microm did not affect the growth of the amebae. although growth was not retarded at these concentrations, the adhesive abilities of e. histolytica and their cytotoxicities to cho cel ...200818344676
loss of dsrna-based gene silencing in entamoeba histolytica: implications for approaches to genetic analysis.the ability to regulate gene expression in the protozoan parasite entamoeba histolytica is critical in determining gene function. we previously published that expression of dsrna specific to e. histolytica serine threonine isoleucine rich protein (ehstirp) resulted in reduction of gene expression [macfarlane, r.c., singh, u., 2007. identification of an entamoeba histolytica serine, threonine, isoleucine, rich protein with roles in adhesion and cytotoxicity. eukaryotic cell 6, 2139-2146]. however ...200818346737
use of giardia, which appears to have a single nucleotide-sugar transporter for udp-glcnac, to identify the udp-glc transporter of entamoeba.nucleotide-sugar transporters (nsts) transport activated sugars (e.g. udp-glcnac) from the cytosol to the lumen of the endoplasmic reticulum or golgi apparatus where they are used to make glycoproteins and glycolipids. udp-glc is an important component of the n-glycan-dependent quality control (qc) system for protein folding. because entamoeba has this qc system while giardia does not, we hypothesized that transfected giardia might be used to identify the udp-glc transporter of entamoeba. here w ...200818346800
entamoeba histolytica encodes unique formins, a subset of which regulates dna content and cell division.the formin family of proteins mediates dynamic changes in actin assembly in eukaryotes, and therefore it is important to understand the function of these proteins in entamoeba histolytica, where actin forms the major cytoskeletal network. in this study we have identified the formin homologs encoded in the e. histolytica genome based on sequence analysis. using multiple tools, we have analyzed the primary sequences of the eight e. histolytica formins and discovered three subsets: (i) e. histolyti ...200818347041
crystal structure of native o-acetyl-serine sulfhydrylase from entamoeba histolytica and its complex with cysteine: structural evidence for cysteine binding and lack of interactions with serine acetyl transferase.cysteine plays a major role in the antioxidative defense mechanisms of the human parasite entameoba histolytica. the major route of cysteine biosynthesis in this parasite is the condensation of o-acetylserine with sulfide by the de novo cysteine biosynthetic pathway involving two key enzymes o-acetyl-l-serine sulfhydrylase (oass) and serine acetyl transferase (sat). the crystal structure of native oass from entameoba histolytica (ehoass) has been determined at 1.86 a resolution and in complex wi ...200818350570
[distribution of intestinal parasites in patients presenting at the environmental-food and medicine analysis laboratory of sivas municipality during the years 1993-2006].the purpose of the present study was to investigate retrospectively the distribution and prevalence of intestinal parasites in patients who presented at the environmental-food and medicine analysis laboratory of the sivas municipality, sivas, from january 1993-december 2006. a total of 732 stool specimens were examined for intestinal parasites using native-lugol and formol ethyl ether methods. also, 186 cellophane tape preparations were examined directly. out of a total of 918 total specimens, i ...200818351554
bipolar spindle frequency and genome content are inversely regulated by the activity of two n-type kinesins in entamoeba histolytica.bipolar microtubular spindles are seen infrequently in entamoeba histolytica trophozoites while monopolar or radial microtubular assemblies are common. additionally, heterogeneity in nuclear dna content and multi-nucleation is found in amoeba cells growing in axenic culture. taken together these observations indicate that genome segregation is irregular in these cells. in order to identify proteins involved in regulating genome segregation, we have focused on studying e. histolytica homologues o ...200818363907
comparison of stool antigen detection kits to pcr for diagnosis of amebiasis.the present study was conducted to compare two stool antigen detection kits with pcr for the diagnosis of entamoeba histolytica infections by using fecal specimens submitted to the department of microbiology at st. vincent's hospital, sydney, and the institute of medical and veterinary science, adelaide, australia. a total of 279 stool samples containing the e complex (e. histolytica, entamoeba dispar, and entamoeba moshkovskii) were included in this study. the stool specimens were tested by usi ...200818367563
the effect of an anti-inflammatory pentapeptide produced by entamoeba histolytica on gene expression in the u-937 monocytic cell line.evaluate the monocyte locomotion inhibitory factor (mlif) effect upon the expression of genes encoding human cytokines, receptors and related factors in the human cell line u-937. mlif (met-gln-cys-asn-ser) is an anti-inflammatory pentapeptide produced by entamoeba histolytica that inhibits many human monocyte functions.200818368290
silencing genes by rna interference in the protozoan parasite entamoeba histolytica.experimental procedures using the rna interference (rnai) approach have recently emerged as a powerful tool for gene silencing in eukaryotic microbes for which gene replacement techniques have not yet been developed. our group has recently explored rnai to knock down gene-specific expression in the protozoan parasite entamoeba histolytica, through delivery of small interfering rna (sirna) oligonucleotides by the soaking approach. standardized conditions for the soaking of e. histolytica trophozo ...200818369782
entamoeba histolytica ehdead1 is a conserved dead-box rna helicase with atpase and atp-dependent rna unwinding activities.rna helicases are widely conserved key enzymes that perform multiple functions in rna metabolism. here, we present the cloning, expression and functional characterization of the ehdead1 rna helicase in the protozoan parasite entamoeba histolytica. according to its primary structure, ehdead1 is evolutionary related to yeast ded1 and human ddx3x rna helicases, both involved in translation and cell cycle regulation. the ehdead1 predicted amino acid sequence exhibits the nine conserved motifs descri ...200818374519
[specific microbiological diagnosis of entamoeba histolytica infection]. 200718383746
intestinal parasites in school aged children and the first case report on amoebiasis in urinary bladder in tripoli, libya.a total of 50 fresh fecal samples were collected from children of either sex and examined by direct wet films and telemann's concentration technique. the results were based on a single stool per person study of the total children ranging from 5-18 years of age, 8 different types of intestinal parasites were recorded. the incidence of infection with one or the other parasites was found to be 42%. double or mixed infection was not uncommon. the infection rates of helminthes were hymenolepis nana 6 ...200718383779
new derivatives of 3,5-substituted-1,4,2-dioxazoles: synthesis and activity against entamoeba histolytica.dioxazole derivatives (1-33) were synthesized in two steps via their corresponding oximes (i-iii). all the compounds were characterized using various spectroscopic techniques. a comparative study of in vitro antiamoebic activity of these heterocyclic compounds, viz. 3-o-chloro (1-11), 3-m-chloro (12-22) and 3-p-chloro (23-33) dioxazoles having same substituents at 5-position of dioxazole ring, was performed against hm1:imss strain of entamoeba histolytica. the results showed a regular pattern in ...200918384916
immunolocalization and enzymatic functional characterization of the thioredoxin system in entamoeba histolytica.the components of the redox metabolism in entamoeba histolytica have been recently revisited by arias et al. (free radic. biol. med. 42:1496-1505; 2007), after the identification and characterization of a thioredoxin-linked system. the present work deals with studies performed for a better understanding of the localization and identification of different components of the redox machinery present in the parasite. the gene encoding for amoebic thioredoxin 8 was cloned and the recombinant protein t ...200818394433
tissue invasion by entamoeba histolytica: evidence of genetic selection and/or dna reorganization events in organ tropism.entamoeba histolytica infection may have various clinical manifestations. nine out of ten e. histolytica infections remain asymptomatic, while the remainder become invasive and cause disease. the most common form of invasive infection is amebic diarrhea and colitis, whereas the most common extra-intestinal disease is amebic liver abscess. the underlying reasons for the different outcomes are unclear, but a recent study has shown that the parasite genotype is a contributor. to investigate this li ...200818398490
prevalence of intestinal parasites in young quichua children in the highlands of rural ecuador.the prevalence of intestinal parasites in young quichua children was assessed in 20 rural communities in the highlands of ecuador in august 2005. the caregivers of 293 children aged 12-60 months were interviewed about the status of child health, household socioeconomic and environmental factors, and water-use practices and were requested to collect a faecal sample from the study child. two hundred three (69.3%) of the 293 children provided faecal samples that were tested for parasites. the overa ...200718402182
transcriptional profile of the homologous recombination machinery and characterization of the ehrad51 recombinase in response to dna damage in entamoeba histolytica.in eukaryotic and prokaryotic cells, homologous recombination is an accurate mechanism to generate genetic diversity, and it is also used to repair dna double strand-breaks. rad52 epistasis group genes involved in recombinational dna repair, including mre11, rad50, nsb1/xrs2, rad51, rad51c/rad57, rad51b/rad55, rad51d, xrcc2, xrcc3, rad52, rad54, rad54b/rdh54 and rad59 genes, have been studied in human and yeast cells. notably, the rad51 recombinase catalyses strand transfer between a broken dna ...200818402694
effects of antacid therapy in asymptomatic patients with presence of amoeba in stool report.amoebic infection caused by the protozoan parasite entamoeba histolytica is a prevalent infection in the developing countries. milder form of this infection is associated with loose stool, flatulence and borborygmi, may or may not be associated with pain in abdomen and treated symptomatically by some physicians by antacid. to find out the effects of antacid (sorbacid) therapy in patients with amoeba in stools by examining the changes in the stool report, a study was conducted among 25 patients e ...200718405098
mpl1, a novel phosphatase with leucine-rich repeats, is essential for proper erk2 phosphorylation and cell motility.the novel dictyostelium phosphatase mpl1 contains six leucine-rich repeats at the amino-terminal end and a phosphatase domain at the carboxyl end. similarly architectured phosphatases exist among other protozoa, such as entamoeba histolytica, leishmania major, and trypanosoma cruzi. mpl1 was strongly induced after 5 h of development; ablation by homologous recombination led to defective streaming and aggregation during development. in addition, cyclic amp (camp)-pulsed mpl1(-) cells showed reduc ...200818408056
amoebic liver abscess or is it? 200818408101
amebic liver abscess: report of three cases.amebic abscess is a common manifestation of extraintestinal amebiasis and it is associated with relatively high morbidity and mortality. we present three cases seen in bari, southern italy, one of which was autochthonous and the other two were not. diagnosis was performed by elevated antibody titre for e. histolytica through immunofluorescence assay and positive antigen determination by elisa in stools and in abscess aspirate. fever often accompanied by chills, abdominal pain, weight loss and he ...200718412043
molecular differentiation of entamoeba histolytica and entamoeba dispar from tunisian food handlers with amoeba infection initially diagnosed by microscopy.the purpose of the study was to obtain more reliable epidemiological data concerning entamoeba (e.) histolytica infection in tunisian food handlers using established molecular tools able to differentiate e. histolytica from e. dispar. from 2002 to 2005, 4,266 fresh stools specimens received in the setting of the national program of food handlers' control were analysed by optical microscopy. twelve (2.8 per thousand) were positive for the presence of four nuclei cysts identified as e. histolytica ...200818416248
unique asn-linked oligosaccharides of the human pathogen entamoeba histolytica.n-glycans of entamoeba histolytica, the protist that causes amebic dysentery and liver abscess, are of great interest for multiple reasons. e. histolytica makes an unusual truncated n-glycan precursor (man(5)glcnac(2)), has few nucleotide sugar transporters, and has a surface that is capped by the lectin concanavalin a. here, biochemical and mass spectrometric methods were used to examine n-glycan biosynthesis and the final n-glycans of e. histolytica with the following conclusions. unprocessed ...200818417475
evaluation of an enzyme-linked immunoassay for the detection of cryptosporidium antigen in fecal specimens of hiv/aids patients.cryptosporidium parvum, a protozoan parasite, causes severe diarrhea in immunodeficient hosts like hiv/aids patients, leading to significant morbidity and mortality. diagnosis of the cryptosporidium oocyst in the stool of these patients by conventional microscopy is labor intensive and time consuming. therefore, we planned to evaluate the usefulness of a stool elisa test in detecting cryptosporidial antigen. about 89 stool specimens obtained from hiv-seropositive patients with diarrhea were subj ...200818417886
chemotaxis of entamoeba histolytica towards the pro-inflammatory cytokine tnf is based on pi3k signalling, cytoskeleton reorganization and the galactose/n-acetylgalactosamine lectin activity.entamoeba histolytica is the protozoan parasite responsible for human amoebiasis. during invasive amoebiasis, migration is an essential process and it has previously been shown that the pro-inflammatory compound tumour necrosis factor (tnf) is produced and that it has a migratory effect on e. histolytica. this paper focuses on the analysis of parasite signalling and cytoskeleton changes leading to directional motility. tnf-induced signalling was pi3k-dependent and could lead to modifications in ...200818419774
[survey of intestinal parasites among an aboriginal community in salta].the prevalence of intestinal parasitoses by protozoans and helminths was determined in an aboriginal community located 6 km from tartagal, province of salta, argentina. the age of the inhabitants studied ranged from 1 to 49 years old. a total of 112 stool samples were collected in sodium acetate-acetic acid- formalin solution (saf). each sample was obtained in three different days, alternatively. ritchie biphasic concentration method and faust flotation technique were applied. for survey of ente ...200718422062
detection of pathogenic protozoa in the diagnostic laboratory: result reproducibility, specimen pooling, and competency assessment.stool microscopy as performed in clinical parasitology laboratories is a complex procedure with subjective interpretation. quality assurance (qa) programs often emphasize proficiency testing as an assessment tool. we describe a result reproducibility assessment tool, which can form part of a broader qa program, and which is based on the blinded resubmission of selected clinical samples, using concordance between the reports of the initial and resubmitted specimen as an indicator. specimens prese ...200818448690
patterns of infection with intestinal parasites in qatar among food handlers and housemaids from different geographical regions of origin.intestinal parasitic infections were surveyed among recently arrived immigrant workers in qatar destined for employment in food handling occupations. two overlapping datasets (female workers surveyed in 2005 and 2006, and both sexes in 2006) were analyzed. seven species were detected, 3 nematodes (trichuris trichiura, hookworms and ascaris lumbricoides) and 4 protozoans (entamoeba histolytica/dispar, non-pathogenic entamoebae, blastocystis hominis and giardia lamblia). overall prevalence of infe ...200818457813
high prevalence of entamoeba moshkovskii in a tanzanian hiv population.entamoeba moshkovskii and entamoeba dispar are microscopically indistinguishable from the pathogenic species entamoeba histolytica. there are limited data on the prevalence of these commensal infections from africa. we utilized pcr and antigen detection to evaluate the carriage rate of e. moshkovskii, e. dispar, and e. histolytica infection in stool from a cohort of hiv-suspected or confirmed inpatients from tanzania. e. histolytica was detected by elisa in 4% (5/118) while e. moshkovskii and e. ...200818471796
gender and genetic control of resistance to intestinal amebiasis in inbred mice.resistance to the establishment of intestinal entamoeba histolytica infection is dependent on the inbred mouse strain. in this work we used the inbred strains b6 (resistant), cba (susceptible), b6cbaf(1) and a backcross of b6cbaf(1) to cba to further examine the genetic basis of resistance. mouse genotype was assessed with single nucleotide polymorphism and microsatellite markers and infection assessed by culture 9 days after intracecal e. histolytica challenge. the backcross population showed a ...200818480826
[history of the entamoeba histolytica protozoan].this article presents a history of entamoeba histolytica spanning since the remote times when it was not even recognized as a cause of human disease to the recent molecular advances. feder losch (1875) in saint petersburg, found amoebae in fecal samples but only regarded them as responsible for maintaining the inflammatory process, not as a cause of dysentery. fritz schaudinn (1903) established the differentiation between entamoeba histolytica and endamoeba coli, schaudinn decided to call it e. ...200818483662
ehmlbp is an essential constituent of the entamoeba histolytica epigenetic machinery and a potential drug target.ehmlbp has been identified as a protein that specifically binds to methylated long interspersed element (line) retrotransposons and rdna in entamoeba histolytica. ehmlbp is unique to entamoeba parasites, which makes this protein a possible drug target for treating amebiasis. in the work described here, we evaluated this potential. downregulation of ehmlbp using antisense technology resulted in trophozoites with impaired growth and cytopathic activity. this indicated that ehmlbp is an essential p ...200818484949
dual infection by chikungunya virus and other imported infectious agent in a traveller returning from india.chikungunya virus infection is a vector-borne self-limiting disease. recent outbreaks in the indian ocean islands have drawn attention to the condition. nevertheless, only a few reports of co-infection with other communicable agents have been reported. the case described now is of a traveller returning from india with concomitant documented chikungunya virus infection associated with systemic amoebiasis. this report highlights the multifaceted pathology that can be encountered with tropical infe ...200818486073
design, synthesis and in vitro antiprotozoal activity of benzimidazole-pentamidine hybrids.a series of ten novel hybrids from benzimidazole and pentamidine were prepared using a short synthetic route. each compound was tested in vitro against the protozoa trichomonas vaginalis, giardia lamblia, entamoeba histolytica, leishmania mexicana, and plasmodium berghei, in comparison with pentamidine and metronidazole. some analogues showed high bioactivity in the low micromolar range (ic(50)<1 microm) against the first four protozoa, which make them significantly more potent than either stand ...200818486471
acanthamoeba castellanii: identification and distribution of actin cytoskeleton.the presence of the cytoskeleton of acanthamoeba castellanii was observed by means of cryo-electronmicroscopy and immunofluorescence techniques. this structure is formed largely by fibers and networks of actin located mainly in cytoplasmic locomotion structures as lamellipodia and as well as in various endocytic structures. in addition, the comparison between total actin content in whole extracts among different amoebae was made. the molecular weight of actin in a. castellanii was 44 kda, and 45 ...200818486940
clinical and serological evidence of toxocara infection in school children from morrope district, lambayeque, peru.the aim of this study was to estimate the frequency of human toxocariosis in a child population from morrope district, lambayeque, peru. from october to december 2005, 182 school children (96 male and 86 female) were studied. blood samples were collected for toxocara elisa-igg test and hematological examination. additionally, stool samples were collected for coproparasitological examination to check cross reactions. we found frequency of positives in 32.4% (59/182) with a significant higher prop ...200818488089
molecular modeling and docking analysis of entamoeba histolytica glyceraldehyde-3 phosphate dehydrogenase, a potential target enzyme for anti-protozoal drug development.the enzymes of the glycolytic pathway constitute an excellent target for the design of new anti-protozoal agents; glyceraldehyde-3 phosphate dehydrogenase catalyzes the reversible oxidative phosphorylation of d-glyceraldehyde 3-phosphate (gap) into d-glycerate 1,3-bisphosphate (1,3-dipg) in the presence of nad+ and inorganic phosphate (p(i)). the prediction of three-dimensional structure of entamoeba histolytica and the docking of the coumarins were performed using the crystal structure of glyce ...200818489439
seroprevalence of viral hepatitis and sexually transmitted disease among adults with recently diagnosed hiv infection in southern taiwan, 2000-2005: upsurge in hepatitis c virus infections among injection drug users.the purpose of this study was to compare the seroprevalence of viral hepatitis and sexually transmitted disease (std) co-infections among three populations at risk recently diagnosed with hiv infection.200818492625
epigenetic transcriptional gene silencing in entamoeba histolytica.the human intestinal pathogen entamoeba histolytica has a number of virulence factors which can cause damage to the host. transcriptional silencing of the gene coding for one of its major toxic molecules, the amoebapore (ehap-a), occurred following the transfection of amoebic trophozoites with a plasmid containing the 5' promoter region of ehap-a as well as a truncated segment of a neighboring, upstream sine1 element that is transcribed from the opposite strand. silencing was dependent on the pr ...200818493998
amebic colitis can mimic tuberculosis and inflammatory bowel disease on endoscopy and biopsy.biopsies of 11 patients with histopathologically diagnosed amebic colitis was evaluated; endoscopically, they were suspected to have tuberculosis or inflammatory bowel disease. amebiasis was suggested in the differential diagnosis in only 3 cases. three patients had purely rectal or sigmoid involvement, whereas the others had ileocecal, cecal, ascending, or transverse colon disease. the biopsies showed cryptitis and depletion of mucin but no crypt branching. crypt abscesses were seen in one biop ...200918499688
bursera fagaroides, effect of an ethanolic extract on ornithine decarboxylase (odc) activity in vitro and on the growth of entamoeba histolytica.the effect of an ethanolic extract from the stem bark of bursera fagaroides on ornithine decarboxylase (odc) activity in vitro and on the growth of entamoeba histolytica was evaluated. for this purpose, increasing concentrations of the extract, up to 8.0mg/ml, were added to amoeba cultures or odc reaction mixtures, which were incubated at 37 degrees c. metronidazole and g418 were added as controls. after 1.5 and 72 h, the odc activity in vitro and growth, respectively, were determined. results r ...200818501354
participation of rho, rock-2, and gap activities during actin microfilament rearrangements in entamoeba histolytica induced by fibronectin signaling.in entamoeba histolytica little is known about the microfilament rearrangements formed by actin and abps. fibronectin regulates many aspects of cell behavior involving the actin cytoskeleton and members of the rho family of small gtpases. using trophozoites interacted with fibronectin and glass, we present evidence related with the formation and regulation of different microfilament rearrangements and their cellular distribution, the effect of actin affecting drugs on these arrangements, and on ...200818501645
seroprevalence of entamoeba histolytica infection in female outpatients at a sexually transmitted disease sentinel clinic in tokyo, japan.from 2003 to 2006, we surveyed the seroprevalence of amoebic infection in female outpatients at a gynecologist's office, which was designated as a sexually transmitted disease sentinel clinic by the tokyo metropolitan government, using an enzyme-linked immunosorbent assay (elisa). the annual rate of anti-entamoeba histolytica (hm-1:imsscl6 strain; hm-1) antibody-positive cases as detected by elisa increased during that period, and anti-chlamydia trachomatis antibodies were detected in 60%, i.e., ...200818503164
etiology of childhood diarrhea in the northeast of brazil: significant emergent diarrheal pathogens.in a study conducted in joão pessoa, northeast of brazil, 2344 escherichia coli isolated from 290 infants with diarrhea and 290 healthy matched controls were analyzed for virulence traits. enteroaggregative e. coli (eaec) was the most prevalent pathogen associated to acute diarrhea. based on the results of colony blot hybridization, serotyping, and hep-2 cell adherence assays, strains were separated in categories as typical enteropathogenic e. coli (epec) (1.7%), atypical epec (a-epec) (9.3%), e ...201018508227
experimental validation of metabolic pathway modeling.in the search for new drug targets in the human parasite entamoeba histolytica, metabolic control analysis was applied to determine, experimentally, flux control distribution of amebal glycolysis. the first (hexokinase, hexose-6-phosphate isomerase, pyrophosphate-dependent phosphofructokinase (pp(i)-pfk), aldolase and triose-phosphate isomerase) and final (3-phosphoglycerate mutase, enolase and pyruvate phosphate dikinase) glycolytic segments were reconstituted in vitro with recombinant enzymes ...200818510554
intestinal invasion by entamoeba histolytica. 200818512355
in silico analysis of est and genomic sequences allowed the prediction of cis-regulatory elements for entamoeba histolytica mrna polyadenylation.in most eukaryotic cells, the poly(a) tail at the 3'-end of messenger rna (mrna) is essential for nuclear export, translatability, stability and transcription termination. poly(a) tail formation involves multi-protein complexes that interact with specific sequences in 3'-untranslated region (3'-utr) of precursor mrna (pre-mrna). here we have performed a computational analysis of a large est and genomic sequences collection from entamoeba histolytica, the protozoan parasite responsible for human ...200818514032
viral, bacterial and parasitic etiology of pediatric diarrhea in gaza, palestine.to determine the etiology of acute diarrhea in palestinian children under 5 years of age and to improve knowledge of the etiology of gastrointestinal pathogens using traditional and molecular diagnostic techniques.200818523397
detection and surveillance of waterborne protozoan parasites.the majority of the world's population still live without access to healthy water and the contamination of drinking water with protozoan pathogens poses a serious threat to millions of people in the developing world. even in the developed world periodic outbreaks of diarrhoeal diseases are caused by the protozoan parasites cryptosporidium sp., giardia duodenalis and entamoeba histolytica. thus, surveillance of drinking water is imperative to minimize such contaminations and ensure continuous sup ...200818524569
differences in complement-mediated killing of entamoeba histolytica between men and women--an explanation for the increased susceptibility of men to invasive amebiasis?men are more than 7 times more likely to develop amebic liver abscess or amebic dysentery caused by entamoeba histolytica than women. because the complement system could play a key role in controlling amebiasis, we determined whether serum from men and women differ in the ability to kill amebic trophozoites. we found that serum from women was significantly more effective in killing e. histolytica trophozoites than serum from men, and this killing was complement dependent. our results provide a p ...200818541770
protozoan protein tyrosine phosphatases.the aim of this review is to provide a synthesis of the published experimental data on protein tyrosine phosphatases from parasitic protozoa, in silico analysis based on the availability of completed genomes and to place available data for individual phosphatases from different unicellular parasites into the comparative and evolutionary context. we analysed the complement of protein tyrosine phosphatases (ptp) in several species of unicellular parasites that belong to apicomplexa (plasmodium; cr ...200818547579
comparison of two immunoassays for detection of entamoeba histolytica.effective diagnostic tools are essential in order to combat disease caused by the parasite entamoeba histolytica. in this study, we compared the commercially available ridascreen entamoeba test (r-biopharm) and the e. histolytica ii test (techlab), and we found that the e. histolytica ii test detects e. histolytica infections more accurately.200818550742
differential induction of immunoregulatory circuits of phagocytic cells by gal/gal nac lectin from pathogenic and nonpathogenic entamoeba.amoebic liver abscess (ala) is an acute inflammatory disease caused by entamoeba histolytica.200818551358
intriguing parasites and intramembrane proteases.rhomboid intramembrane proteases occur throughout the kingdoms of life. in this issue of genes & development, baxt and colleagues (pp. 1636-1646) report that the single proteolytic rhomboid (ehrom1) from entamoeba histolytica cleaves cell surface galactose-binding or n-acetylgalactosamine-binding (gal/gal-nac) lectins. ehrom1 and lectins colocalize during phagocytosis and receptor capping. ehrom1 is found at the base of the cap rather than in the cap proper, suggesting a role in receptor sheddin ...200818559471
an entamoeba histolytica rhomboid protease with atypical specificity cleaves a surface lectin involved in phagocytosis and immune evasion.rhomboid proteases are membrane-embedded enzymes conserved in all kingdoms of life, but their cellular functions across evolution are largely unknown. prior work has uncovered a role for rhomboid enzymes in host cell invasion by malaria and related intracellular parasites, but this is unlikely to be a widespread function, even in pathogens, since rhomboid proteases are also conserved in unrelated protozoa that maintain an extracellular existence. we examined rhomboid function in entamoeba histol ...200818559479
the prevalence of intestinal parasites and nasal s. aureus carriage among food handlers.food handlers play a major role in the transmission of foodborne diseases. nasal staphylococcus aureus (s. aureus) carriage and intestinal parasitism are important risk factors in contamination. the purpose of the authors' study was to determine the prevalence of intestinal parasites and nasal s. aureus carriage among food handlers in manisa, turkey. the authors investigated 8,895 people for nasal s. aureus carriage and intestinal parasites. nasal swab materials and stool samples were examined, ...200818561571
detection of entamoeba histolytica antigen in stool samples in mersin, turkey.entameoba histolytica, 1 of the 2 entamoeba species with similar morphology that infect humans, causes invasive intestinal and extraintestinal diseases, whereas entamoeba dispar is found commensally and is noninvasive. because of their morphologic similarity, e. histolytica and e. dispar cannot be differentiated microscopically. the antigens of e. histolytica and e. dispar, however, may be detected by the elisa method. previous studies have found that the detection of antigens in the stool is as ...200818564756
a case report: entamoeba histolytica infections in the rhesus macaque, china.a case of amebic dysentery due to a natural infection of entamoeba histolytica in the rhesus macaque (macaca mullata) was reported. a fecal specimen was isolated and identified by the polymerase chain reaction technique. a daily dose of 750 mg of metronidazole was given orally for 10 days, and good results were observed. the early diagnosis of an e. histolytica infection allowed a proper antiamoebic treatment in an early stage of infection resulting in a successful outcome after therapy.200818566832
molecular epidemiology of amebiasis.entamoeba histolytica, the causative agent of human amebiasis, remains a significant cause of morbidity and mortality in developing countries and is responsible for up to 100,000 deaths worldwide each year. entamoeba dispar, morphologically indistinguishable from e. histolytica, is more common in humans in many parts of the world. similarly entamoeba moshkovskii, which was long considered to be a free-living ameba, is also morphologically identical to e. histolytica and e. dispar, and is highly ...200818571478
degradation of human secretory iga1 and iga2 by entamoeba histolytica surface-associated proteolytic activity.the protozoan entamoeba histolytica is the etiological agent of amebiasis, an infection with high prevalence worldwide. the host-ameba relationship outcome depends on parasite and host factors, and among these is secretory iga. these antibodies reduce mucosal colonization by pathogens and neutralize a variety of toxins and enzymes. the functionality of secretory iga depends on its integrity. some bacteria produce iga proteases that cleave mainly the iga1 subclass; live e. histolytica trophozoite ...200818571975
assessment of entamoeba histolytica antigen in stool samples in mersin.entameoba histolytica, one of the two entamoeba species with similar morphology that infect humans, causes invasive intestinal and extra-intestinal diseases, whereas entamoeba dispar is found commensally and is non-invasive. due to their morphologic similarity, e. histolytica and e. dispar cannot be differentiated microscopically. the antigens of e. histolytica and e. dispar may be detected by the elisa method. previous studies have found that the detection of antigens in the stool is as sensiti ...200818576733
cockroaches as carriers of human intestinal parasites in two localities in ethiopia.a study was undertaken to assess the role of cockroaches as potential carriers of human intestinal parasites in addis ababa and ziway, ethiopia. a total of 6480 cockroaches were trapped from the two localities from october 2006 to march 2007. all the cockroaches trapped in addis ababa (n=2240) and almost 50% (2100/4240) of those trapped in ziway were identified as blattella germanica. the rest of the cockroaches trapped in ziway were identified as periplaneta brunnea (24.52%), pycnoscelus surina ...200818579170
entamoeba histolytica: lipid rafts are involved in adhesion of trophozoites to host extracellular matrix components.adhesion is an important virulence function for entamoeba histolytica, the causative agent of amoebic dysentery. lipid rafts, cholesterol-rich domains, function in compartmentalization of cellular processes. in e. histolytica, rafts participate in parasite-host cell interactions; however, their role in parasite-host extracellular matrix (ecm) interactions has not been explored. disruption of rafts with a cholesterol extracting agent, methyl-beta-cyclodextrin (mbetacd), resulted in inhibition of ...200818588878
cost-effectiveness of detection of intestinal amebiasis by using serology and specific-amebic-antigen assays among persons with or without human immunodeficiency virus infection.among 345 persons who underwent indirect hemagglutination (iha) serological assays and assays of specific amebic antigens in their stool samples, 24 of 36 (66.7%) who were seropositive for entamoeba histolytica had intestinal amebiasis as determined by antigen assays compared with 2 of 309 (0.2%) who were seronegative (odds ratio, 307; 95% confidence interval, 64.9 to 1,451). the estimated cost to detect a case of intestinal amebiasis by serology followed by antigen assays ($52) could be reduced ...200818596142
invasive amebiasis in men who have sex with men, australia.entamoeba histolytica is a pathogenic ameba that has recently been recognized as an emerging pathogen in men who have sex with men (msm) in asia-pacific countries where it is not endemic, i.e., japan, taiwan, and republic of korea. we report locally acquired invasive amebiasis in sydney, australia, exclusively in msm.200818598643
treatment of symptomatic amebic colitis in human immunodeficiency virus-infected persons.while most entamoeba histolytica appearing in male homosexuals infected with human immunodeficiency virus (hiv) is considered non-invasive in western countries, and treatment of amebiasis in these persons has received very little attention, in japan some male homosexual amebiasis patients infected with hiv complain of symptoms attributable to e. histolytica infection. we investigated whether symptomatic e histolytica amebic colitis in hiv-infected persons requires higher doses or longer duration ...199618611760
protein ser/thr phosphatases of parasitic protozoa.protein phosphorylation is an important mechanism implicated in physiology of any organism, including parasitic protozoa. enzymes that control protein phosphorylation (kinases and phosphatases) are considered promising targets for drug development. this review attempts to provide the first account of the current understanding of the structure, regulation and biological functions of protein ser/thr phosphatases in unicellular parasites. we have examined the complements of phosphatases ("phosphato ...200818619495
the risk of pathogenic intestinal parasite infections in kisii municipality, kenya.intestinal parasitic infections are among the most common infections worldwide. various epidemiological studies indicate that the prevalence of intestinal parasites is high especially in developing countries, although in many of these, the environmental risk factors have not been clearly elucidated. the objective of this study was to determine the risk of pathogenic intestinal parasites infections in kisii municipality.200818620608
amoebiasis among patrons visiting gay saunas in taiwan.this study aimed to assess the prevalence of amoebiasis among patrons visiting gay saunas in taiwan.200818624723
ehhmbp45 is a novel hemoglobin-binding protein identified in entamoeba histolytica.hemoglobin-binding proteins are necessary for pathogens to obtain iron from hb. entamoeba histolytica can grow using hb as source of iron, but the underlying mechanism has not previously been established. in this work, we identified a 45 kda hb-binding protein of e. histolytica, which we named ehhmbp45. in silico analysis showed that ehhmbp45 contains the conserved domains needed for hb-binding, while overlay assays demonstrated that ehhmbp45 is able to bind hb. in addition, we found that ehhmbp ...200818625230
amebic liver abscess in a patient with polycystic disease. 200818626440
extracellular alix regulates integrin-mediated cell adhesions and extracellular matrix assembly.alix (alg-2-interacting protein x), a cytoplasmic adaptor protein involved in endosomal sorting and actin cytoskeleton assembly, is required for the maintenance of fibroblast morphology. as alix has sequence similarity to adhesin in entamoeba histolytica, and we observed that alix is secreted, we determined whether extracellular alix affects fibroblast morphology. here, we demonstrate that secreted alix is deposited on the substratum of non-immortalized wi38 fibroblasts. antibody binding to extr ...200818636094
enteric parasitic infections in hiv/aids patients before and after the highly active antiretroviral therapy.enteroparasites are related to gastrointestinal alterations among patients with hiv/aids, some causing severe manifestations in the period before the institution of the highly active antiretroviral therapy (haart). the prevalence of enteroparasitoses in patients with hiv/aids seen at two hospitals in ceará , brazil, was compared in the pre-haart (group 1; n = 482) and haart (group 2; n = 100) eras. fecal parasitologic examinations (fpe) were performed using the direct, lutz, baermann-moraes and ...200818641847
primary cutaneous amebiasis with a fatal outcome.we report a fatal case of disseminated amebiasis in a young african woman, which initially presented with an ulcerated cutaneous lesion on the left flank. the causative organism was confirmed by examination of a wet drop preparation from the ulcer discharge and by skin biopsy. the patient was not immunosuppressed and was treated unsuccessfully with metronidazole. postmortem examination revealed the presence of intestinal amebiasis complicated by a liver abscess.200818645316
[the prevalence of intestinal parasites according to the distribution of the patients' gender and parasite species for five years at the osmangazi university medical faculty].in this study, patients (outpatients and inpatients) with various gastrointestinal system complaints presenting at various clinics of the eskisehir osmangazi university medical faculty, from february 2003-december 2007 were investigated for the presence of intestinal parasites. the prevalence of intestinal parasites was evaluated according to parasite species, gender of the patients and the years, in which cases were seen. a total of 34,733 stool samples were prepared by formal-ethyl acetate con ...200818645941
the interplay between entamoeba and enteropathogenic bacteria modulates epithelial cell damage.mixed intestinal infections with entamoeba histolytica, entamoeba dispar and bacteria with exacerbated manifestations of disease are common in regions where amoebiasis is endemic. however, amoeba-bacteria interactions remain largely unexamined.200818648517
characterization of an entamoeba histolytica high-mobility-group box protein induced during intestinal infection.the unicellular eukaryote entamoeba histolytica is a human parasite that causes amebic dysentery and liver abscess. a genome-wide analysis of gene expression modulated by intestinal colonization and invasion identified an upregulated transcript that encoded a putative high-mobility-group box (hmgb) protein, ehhmgb1. we tested if ehhmgb1 encoded a functional hmgb protein and determined its role in control of parasite gene expression. recombinant ehhmgb1 was able to bend dna in vitro, a characteri ...200818658254
antiamoebic coumarins from the root bark of adina cordifolia and their new thiosemicarbazone derivatives.in continuation of our search for potential antiamoebic agents from folklore indian medicinal plants, we found that the benzene and ethyl acetate extracts from the root bark of adina cordifolia exhibited strong antiamoebic activity with ic(50) values of 2.92 and 2.50 microg/ml, respectively. bioassay-guided fractionation of benzene and ethyl acetate extracts led to the isolation of 7-hydroxycoumarin (umbelliferone 1) and 7-beta-d-glucosylcoumarin (skimmin 2), respectively. umbelliferone 1 was co ...200918675491
crystallization and preliminary x-ray analysis of l-methionine gamma-lyase 1 from entamoeba histolytica.l-methionine gamma-lyase (mgl) is a pyridoxal phosphate-dependent enzyme that is involved in the degradation of sulfur-containing amino acids. mgl is an attractive drug target against amoebiasis because the mammalian host of its causative agent entamoeba histolytica lacks mgl. for the development of anti-amoebic agents based on the structure of mgl, one of two mgl isoenzymes (ehmgl1) was crystallized in the monoclinic space group p2(1), with unit-cell parameters a = 99.12, b = 85.38, c = 115.37 ...200818678935
amebic colitis in an antigenically and serologically negative patient: usefulness of a small-subunit ribosomal rna gene-based polymerase chain reaction in diagnosis.specific identification of entamoeba histolytica in clinical specimens is an essential confirmatory diagnostic step in the management of amebiasis. here, we report an unusual case of amebic colitis in a 20-year-old female immigrant from south china. the patient had experienced diarrhea, crampy abdominal pain, and fever for approximately 3 weeks prior to admission to hospital and had treated herself at home with metronidazole. on admission, stool microscopy and serology for e. histolytica were ne ...200818691843
"inject-mix-react-separate-and-quantitate" (imresq) method for screening enzyme inhibitors.many regulatory enzymes are considered attractive therapeutic targets, and their inhibitors are potential drug candidates. screening combinatorial libraries for enzyme inhibitors is pivotal to identifying hit compounds for the development of drugs targeting regulatory enzymes. here, we introduce the first inhibitor screening method that consumes only nanoliters of the reactant solutions and is applicable to regulatory enzymes. the method is termed inject-mix-react-separate-and-quantitate (imresq ...200818702487
c1q- and collectin-dependent phagocytosis of apoptotic host cells by the intestinal protozoan entamoeba histolytica.entamoeba histolytica, the cause of invasive amebiasis, phagocytoses apoptotic host cells during tissue invasion. in mammals, collectin family members (e.g., mannose-binding lectin [mbl]) and the structurally related protein c1q bind to apoptotic cells and stimulate macrophage phagocytosis via a conserved collagenous tail domain. the collectins also bind to bacteria, the usual source of nutrients for e. histolytica.200818702607
prostaglandin e2 produced by entamoeba histolytica binds to ep4 receptors and stimulates interleukin-8 production in human colonic cells.entamoeba histolytica pathogenesis in the colon occurs in a stepwise fashion. it begins with colonization of the mucin layer, which is followed by stimulation of a proinflammatory response that causes nonspecific tissue damage that may facilitate parasite invasion of the underlying colonic mucosa. unfortunately, the parasite and/or host factors that stimulate a proinflammatory response in the gut are poorly understood. in this study, we found that live e. histolytica or secretory or proteins (sp ...200818710858
entamoeba shows reversible variation in ploidy under different growth conditions and between life cycle phases.under axenic growth conditions, trophozoites of entamoeba histolytica contain heterogenous amounts of dna due to the presence of both multiple nuclei and different amounts of dna in individual nuclei. in order to establish if the dna content and the observed heterogeneity is maintained during different growth conditions, we have compared e. histolytica cells growing in xenic and axenic cultures. our results show that the nuclear dna content of e. histolytica trophozoites growing in axenic cultur ...200818714361
[epidemiologic and molecular study of entamoeba histolytica and entamoeba dispar strains in pacients with diarrhea in cumana, sucre state, venezuela].an epidemiological and molecular study on e. histolytica and e. dispar was carried out in 428 patients with gastrointestinal symptomatology of diarrhea from different health centers in cumana, sucre state. the samples were processed through: direct examination with 0.85% physiological saline solution, temporal lugol staining, trichromic staining and the ritchie method of concentration; a sucrose gradient was used for cyst isolation. the small subunit of the 16s rna was amplified by nested, multi ...200818717268
[amebiasis: importance of the diagnosis and treatment. minireview].the protozoa e. histolytica is the etiologic agent of human amebiasis, the identification of its pathogenicity has been of great aid in the search of important antigens for immunodiagnostic and inmunoprofilaxis. in 1995 the isolation and axenization of the first two strains of venezuelan e. histolytica were described from symptomatic patients, which were denominated: iula 1092:1 and iula: 0593:2 these strains have been evaluated through studies of electrophoretic profiles, demonstrating the pres ...200818717272
crusaders' dysentery. 200818718438
ulcers and the colon: keep an open mind. 200818719135
new insights into entamoeba histolytica pathogenesis.entamoeba histolytica is an important global pathogen and a leading cause of parasitic death worldwide. this article summarizes significant research findings over the last year.200818725798
entamoeba histolytica spread by food. 198618749951
putative dead and dexh-box rna helicases families in entamoeba histolytica.rna helicases catalyze the unwinding of double-stranded rna structures to perform numerous genetic processes. these enzymes are characterized by the presence of a conserved helicase domain with specific helicases motifs whose amino acid sequence allows the differentiation between dead and dexh-box rna helicase families. taking advantage of the availability of the complete genome sequence of entamoeba histolytica, the protozoan responsible for human amoebiasis, we have performed a genomic survey ...200818760338
entamoeba histolytica modulates a complex repertoire of novel genes in response to oxidative and nitrosative stresses: implications for amebic pathogenesis.upon host infection, the protozoan parasite entamoeba histolytica is confronted with reactive oxygen and nitrogen species and must survive these stresses in order to cause invasive disease. we analysed the parasite's response to oxidative and nitrosative stresses, probing the transcriptional changes of trophozoites of a pathogenic strain after a 60 min exposure to h2o2 (1 mm) or a no donor (dipropylenetriamine-nonoate, 200 microm), using whole-genome dna microarrays. genes encoding reactive oxyg ...200918778413
amebic cerebral abscess mimicking bacterial meningitis.we report a case of an amebic brain abscess in a 2-year-old girl, with symptoms mimicking bacterial meningitis with no evidence of disease elsewhere. histological evaluation of the abscess revealed the organisms, and the abscess regressed in response to specific medical treatment. this article reviews the rarity of these abscesses and difficulty in the diagnosis.200818810346
mechanisms of infectious diarrhea.infectious diarrhea is an important public health problem worldwide. research has provided new insights into the mechanisms of diarrhea caused by various pathogens that are classified as noninflammatory, inflammatory or invasive. these three groups of organisms cause two diarrheal syndromes--noninflammatory diarrhea and inflammatory diarrhea. the noninflammatory diarrheas are caused by enterotoxin-producing organisms such as vibrio cholerae and enterotoxigenic escherichia coli, or by viruses tha ...200818813221
trophozoites of entamoeba histolytica epigenetically silenced in several genes are virulence-attenuated.the human intestinal parasite entamoeba histolytica causes amoebic colitis and amoebic liver abscesses. three classes of amoebic molecules have been identified as the major virulence factors, the gal/galnac inhibitable lectin that mediates adherence to mammalian cells, the amoebapores which cause the formation of membrane ion channels in the target cells and the cysteine proteinases which degrade the matrix proteins, the intestinal mucus and secretory iga. transcriptional silencing of the amoeba ...200818814693
a survey of amoebic infections and differentiation of an entamoeba histolytica-like variant (jsk2004) in nonhuman primates by a multiplex polymerase chain reaction.a pathogenic entamoeba histolytica-like variant (jsk2004 strain) with genetic variations and a novel isoenzyme pattern isolated from a de brazza's guenon in a tokyo zoo in japan has previously been documented. in this study, a multiplex polymerase chain reaction (pcr) assay that could distinguish the jsk2004-type e. histolytica-like variant (jsk04-eh-v) from e. histolytica and entamoeba dispar using three newly designed primer sets for amplifying each specific dna fragment from their small-subun ...200818816999
analysis of commercial entamoeba histolytica elisa kits for the detection of entamoeba invadens in reptiles.entamoeba invadens is pathogenic in multiple reptile species and has caused severe outbreaks in zoos and other facilities worldwide. infections can be difficult to diagnose and to differentiate from other reptilian entamoeba species. the goal of this study was to determine if kits developed to identify the human pathogen entamoeba histolytica could be used to detect e. invadens in reptile species at the maryland zoo. the e. histolytica ii antigen enzyme-linked immunosorbent assay and the prospec ...200818817019
public health importance of non-biting cyclorrhaphan flies.this study was carried out to determine the role of non-biting cyclorrhaphan flies as carriers of human intestinal parasites at woreta, northwestern ethiopia. in total, 6530 flies were collected from four breeding sites and then examined for human intestinal parasites, mainly using the formol-ether concentration method. fly species identified were musca domestica (32.9%), chrysomya rufifacies (32.6%), musca sorbens (23%), lucina cuprina (4.7%), calliphora vicina (2.8%), chrysomya bezziana (2.3%) ...200918817940
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