Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
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
entamoeba histolytica: cyst-like structures in vitro induction.the cyst of entamoeba histolytica is responsible for amebiasis infection. however, no axenic in vitro system exists that promotes mass encystation for studying this process of this human-infecting parasite. cyst-like structures of e. histolytica obtained in this work were induced using tyi-s-33 media in combination with enterobacterias escherichia coli and enterococcus faecalis conditioned media, high co2 tension and histamine. cyst-like structures showed the same characteristics of a typical e. ...200818083165
participation of the serine-rich entamoeba histolytica protein in amebic phagocytosis of apoptotic host cells.entamoeba histolytica is an intestinal ameba that causes dysentery and liver abscesses. cytotoxicity and phagocytosis of host cells characterize invasive e. histolytica infection. prior to phagocytosis of host cells, e. histolytica induces apoptotic host cell death, using a mechanism that requires contact via an amebic galactose-specific lectin. however, lectin inhibition only partially blocks phagocytosis of already dead cells, implicating at least one additional receptor in phagocytosis. to id ...200818086807
hepatic and inferior vena caval thrombosis: vascular complication of amebic liver abscess.although amebic liver abscess is a common disease, it is a rare cause of venous thrombosis. computed tomography (ct) scan is an ideal tool for diagnosing the various complications associated with liver abscess. we describe a case of amebic liver abscess in a patient who developed a rare vascular complication of hepatic vein and inferior vena cava thrombosis.200818022781
entamoeba histolytica: genetic diversity of african strains based on the polymorphism of the serine-rich protein gene.the polymorphism of the serine-rich entamoeba histolytica protein (srehp) among isolates obtained from different geographic regions was analyzed by a nested pcr followed by restriction analysis. thirteen different profiles were generated from 23 e. histolytica isolates from cameroon, zimbabwe and south africa while 20 others were generated from 38 e. histolytica pcr positive stool samples from south africa. one of the profiles was common to isolates from cameroon, zimbabwe and south africa and c ...200818028911
in silico identification of the protein disulfide isomerase family from a protozoan parasite.protein disulfide isomerase (pdi) enzymes are eukaryotic oxidoreductases that catalyze the correct formation of disulfide bonds during protein folding. structurally they are characterized by the presence of functional thioredoxin-like (trx) domains. for the protozoan parasite causative of the human amebiasis (entamoeba histolytica), the correct formation of disulfide bonds is important for an accurate folding of its proteins, including some virulence factors. however, little is known about the e ...200817981509
protozoadb: dynamic visualization and exploration of protozoan genomes.protozoadb (http://www.biowebdb.org/protozoadb) is being developed to initially host both genomics and post-genomics data from plasmodium falciparum, entamoeba histolytica, trypanosoma brucei, t. cruzi and leishmania major, but will hopefully host other protozoan species as more genomes are sequenced. it is based on the genomics unified schema and offers a modern web-based interface for user-friendly data visualization and exploration. this database is not intended to duplicate other similar eff ...200817981844
toll-like receptor 9-dependent macrophage activation by entamoeba histolytica dna.activation of the innate immune system by bacterial dna and dna of other invertebrates represents a pathogen recognition mechanism. in this study we investigated macrophage responses to dna from the intestinal protozoan parasite entamoeba histolytica. e. histolytica genomic dna was purified from log-phase trophozoites and tested with the mouse macrophage cell line raw 264.7. raw cells treated with e. histolytica dna demonstrated an increase in levels of tumor necrosis factor alpha (tnf-alpha) mr ...200817984204
attenuated recombinant yersinia as live oral vaccine carrier to protect against amoebiasis.various attenuated yersinia enterocolitica strains expressing different sections of the entamoeba histolytica surface lectin via the type iii protein secretion system (t3ss) were assessed for their use to orally vaccinate rodents against invasive amoebiasis. the t3ss was found to efficiently express and secrete or translocate subfragments as well as the entire heavy subunit of the lectin. oral vaccination with recombinant yersinia conferred significant protection against amoebic liver abscess fo ...200817900982
comparative genomics of transcription factors and chromatin proteins in parasitic protists and other eukaryotes.comparative genomics of parasitic protists and their free-living relatives are profoundly impacting our understanding of the regulatory systems involved in transcription and chromatin dynamics. while some parts of these systems are highly conserved, other parts are rapidly evolving, thereby providing the molecular basis for the variety in the regulatory adaptations of eukaryotes. the gross number of specific transcription factors and chromatin proteins are positively correlated with proteome siz ...200817949725
inhibitors of escherichia coli serine acetyltransferase block proliferation of entamoeba histolytica trophozoites.the protozoan parasite entamoeba histolytica is the etiologic agent of amebiasis, a major global public health problem, particularly in developing countries. there is an effective anti-amoebic drug available, however its long term use produces undesirable side effects. as e. histolytica is a micro-aerophilic organism, it is sensitive to high levels of oxygen and the enzymes that are involved in protecting against oxygen-stress are crucial for its survival. therefore serine acetyltransferase, an ...200817991467
analysis of the protein kinome of entamoeba histolytica.protein kinases play important roles in almost all major signaling and regulatory pathways of eukaryotic organisms. members in the family of protein kinases make up a substantial fraction of eukaryotic proteome. analysis of the protein kinase repertoire (kinome) would help in the better understanding of the regulatory processes. in this article, we report the identification and analysis of the repertoire of protein kinases in the intracellular parasite entamoeba histolytica. using a combination ...200818004777
intestinal parasitism and vibrio cholerae infection among diarrhoeal patients in kolkata, india.in this study, we have analysed the epidemiological significance of the concurrent infections caused by vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in kolkata. a total of 3556 stool samples collected during 1996-2004 were screened for vibrios and parasites. the seasonality of v. cholerae and parasitic infections were studied in detail. the detection rates for ascaris lumbricoides and giardia lamblia infection were more than for the hook ...200817594735
acetylation of the entamoeba histone h4 n-terminal domain is influenced by short-chain fatty acids that enter trophozoites in a ph-dependent manner.treatment of higher eukaryotic cells with short-chain fatty acids (scfa) such as butyrate causes decreased levels of histone deacetylase (hdac) activity and hyperacetylation of histones, and thereby affects gene expression, cell growth and differentiation. entamoeba parasites encounter high levels of scfa in the host colon, and in vitro these compounds allow trophozoite stage parasites to multiply but prevent their differentiation into infectious cysts. the entamoeba invadens ip-1 histone h4 pro ...200817706222
molecular modeling on pyruvate phosphate dikinase of entamoeba histolytica and in silico virtual screening for novel inhibitors.pyruvate phosphate dikinase (ppdk) is the key enzyme essential for the glycolytic pathway in most common and perilous parasite entamoeba histolytica. inhibiting the function of this enzyme could control the wide spread of intestinal infections caused by entamoeba histolytica in humans. with this objective, we modeled the three dimensional structure of the ppdk protein. we used templates with 51% identity and 67% similarity to employ homology-modeling approach. stereo chemical quality of protein ...200817710553
the lysine- and glutamic acid-rich protein kerp1 plays a role in entamoeba histolytica liver abscess pathogenesis.the parasite entamoeba histolytica colonizes the large bowel where it may persist as an asymptomatic luminal gut infection, which changes to virulence. parasite invasion of the intestine leads to dysentery and spreads to the liver, where amoebae form abscesses. we took advantage of changes in virulence that occurs after long-term in vitro culture of e. histolytica strains. using microarrays, we concluded that virulence correlates with upregulation of key genes involved in stress response, includ ...200817711481
entamoeba histolytica: fibrilar aggregates in dividing trophozoites.entamoeba histolytica trophozoite cytokinesis is dependent upon cytoskeletal elements such as filamentous actin and myosin. here we present confocal and transmission electron microscopy studies of this process. a sequence in the formation of the contractile ring was shown with rhodamine-phalloidine staining. ultrastructural analysis revealed the presence of fibrilar aggregates in the cytoplasm of dividing trophozoites. among them two filaments of different diameter were identified. these aggrega ...200817870071
forest fragmentation, the decline of an endangered primate, and changes in host-parasite interactions relative to an unfragmented forest.forest fragmentation may alter host-parasite interactions in ways that contribute to host population declines. we tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in kibale national park, uganda. over 4 years, the endangered red colobus (procolobus rufomitratus) declined by 20% in fragments, whereas the black-and-white colobus (colobus guereza) in fragments and populations of both colobines in unfra ...200817879941
entamoeba histolytica mitosomes: organelles in search of a function.it has been more than eight years since the discovery of mitosomes (mitochondrial remnant organelles) in the intestinal human pathogen entamoeba histolytica. despite detailed knowledge about the biochemistry of this parasite and the completion of the e. histolytica genome sequencing project no physiological function has yet been unequivocally assigned to these organelles. entamoeba mitosomes seem to be the most degenerate of all endosymbiosis-derived organelles studied to date. they do not appea ...200817880942
an epitope-specific pcr test for diagnosis of leishmania donovani infections.the carboxy-terminal region of recombinant heat shock protein 70 of leishmania donovani has been shown to have an immunodominant epitope. we designed a pcr assay using a new set of primers encompassing the gene sequence from 457bp to 927bp, which amplified a segment of the l. donovani genome in a species-specific manner. the assay was sensitive enough to detect 0.5pg of parasite dna, which increased 10-fold (0.05pg) when an internal probe (583-609bp) was used in the southern blot. the assay was ...200817888473
progress and prospects of gene inactivation in entamoeba histolytica.over the last few years, numerous methods have been exploited in the attempt to study entamoeba histolytica gene functions. yet several features of e. histolytica, like their variable dna content and complex ploidity have made it difficult to perform classical genetic studies such as homologous recombination. as a result, the methods currently in use target genes at the protein or rna level. this review summarizes the experimental approaches that have been used to date and it provides an overvie ...200817889851
differential native state ruggedness of the two ca2+-binding domains in a ca2+ sensor protein.characterization of near-native excited states of a protein provides insights into various biological functions such as co-operativity, protein-ligand, and protein-protein interactions. in the present study, we investigated the ruggedness of the native state of ehcabp using nonlinear temperature dependence of backbone amide-proton chemical shifts. ehcabp is a two-domain ef-hand calcium sensor protein consisting of two ef-hands in each domain and binds four ca2+ ions. it has been observed that ap ...200817912755
autophagy during proliferation and encystation in the protozoan parasite entamoeba invadens.autophagy is one of the three systems responsible for the degradation of cytosolic proteins and organelles. autophagy has been implicated in the stress response to starvation, antigen cross-presentation, the defense against invading bacteria and viruses, differentiation, and development. saccharomyces cerevisiae atg8 and its mammalian ortholog, lc3, play an essential role in autophagy. the intestinal protozoan parasite entamoeba histolytica and a related reptilian species, entamoeba invadens, po ...200817923513
novel pd(ii) complexes of 1-n-substituted 3-phenyl-2-pyrazoline derivatives and evaluation of antiamoebic activity.cyclization of mannich base with n(4)-substituted thiosemicarbazides by different aliphatic, aromatic and cyclic amines afforded a series of new 1-n-substituted cyclised pyrazoline analogues of thiosemicarbazones (pyz-tsc) 1-10. reaction of [pd(dmso)(2)cl(2)] with pyrazoline derivatives led to new palladium(ii) complexes [pd(pyz-tsc)cl(2)] 1a-10a. the structures of all the compounds were characterized by spectroscopic methods. it was concluded that the pyrazoline thiosemicarbazone derivatives ha ...200817513021
diagnosis of entamoeba histolytica in symptomatic children, jeddah city, saudi arabia.amebiasis is one of the most common parasitic infections worldwide. entamoeba histolytica and entamoeba dispar are two morphologically indistinguishable human protozoa parasites that are genetically distinct species. differential diagnosis of e. histolytica (pathogenic) and e. dispar (non-pathogenic) is essential both for treatment decision and public health knowledge. stool samples from 500 randomly selected children complaining of gastroenteritis were examined microscopically by direct wet sme ...200820306672
analysis of autophagy in the enteric protozoan parasite entamoeba.entamoeba histolytica is the enteric protozoan parasite that causes human amoebiasis. we have previously shown that autophagy is involved in proliferation and differentiation in the related species entamoeba invadens, which infects reptiles and develops similar clinical manifestations. because this group of protists possesses only a limited set of genes known to participate in autophagy in other eukaryotes, it potentially represents a useful model for studying the core system of autophagy and pr ...200819185732
the divergent eukaryote trichomonas vaginalis has an m7g cap methyltransferase capable of a single n2 methylation.eukaryotic rnas typically contain 5' cap structures that have been primarily studied in yeast and metazoa. the only known rna cap structure in unicellular protists is the unusual cap4 on trypanosoma brucei mrnas. we have found that t. vaginalis mrnas are protected by a 5' cap structure, however, contrary to that typical for eukaryotes, t. vaginalis spliceosomal snrnas lack a cap and may contain 5' monophophates. the distinctive 2,2,7-trimethylguanosine (tmg) cap structure usually found on snrnas ...200818957443
protozoa in respiratory pathology: a review.among the micro-organisms that may affect the respiratory apparatus are the protozoa. the diseases they may give rise to constitute a relatively uncommon group of respiratory ailments with, in the majority of cases, an underlying clinical situation corresponding to states of suppressed immunity (aids, transplants, malign haemopathies, corticotherapy, etc.). other factors, such as visits to endemic areas and immigration, also have to be taken into account. in view of the probable increase in the ...200818978136
localization of entamoeba histolytica amebopore in amebic liver abscesses in hamsters.amebopore was purified from axenically grown trophozoites of the entamoeba histolytica strain hm1:imss. the purification procedure involved mono q anion-exchange chromatography and electroelution. sequence analysis of the final product revealed that amebopore a was completely pure. polyclonal antibodies against the purified amebopore were obtained from rabbits, and western blot studies demonstrated their specificity. sections of experimental, acute (1, 2, 3, and 4 days), amebic liver abscesses p ...200819120254
enteric protozoan parasitic infection in hiv seropositive individuals with diarrhoea.a total of 78 hiv seropositive patients were included in the study from january 2004 to march 2006. enteric protozoan parasitic infections were diagnosed by microscopic examination of stool by fresh wet mount, stool smears stained by modified z.n., trichrome and calcofluor white stains. 20 samples (25.6%) revealed presence ofenteric protozoan parasites.200819127672
intestinal parasitosis in nalout popularity, western libya.this paper studied gastrointestinal parasitosis in nalout popularity. a hospital based study was done on a total of 800 stool samples from a private laboratory in tigi city. the results showed an overall rate of 29.6%. of these patients, 7.59% had double or triple parasitic infections. children were more infected than adults. the parasites in a descending order were entamoeba histolytica (21%), enterobius vermicularis (7.5%), giardia lamblia (2.5%), balantidium coli (0.38%), and hymenolepis nana ...200819143135
parasitiosis in handicapped children in an egyptian blind asylum.examination of visually handicapped children and their serving staff revealed in a descending order enterobius vermicularis, giardia lamblia, entamoeba histolytica, hymenolepis nana, ascaris lumbricoides, cryptospodium parvum, tricocephalus trichura and strongyloides stercoralis. head lice were encountered. but, neither blood parasites nor protozoan infective agent in water for human consumption.200819143142
genome wide survey, discovery and evolution of repetitive elements in three entamoeba species.identification and mapping of repetitive elements is a key step for accurate gene prediction and overall structural annotation of genomes. during the assembly and annotation of three highly repetitive amoeba genomes, entamoeba histolytica, entamoeba dispar, and entamoeba invadens, we performed comparative sequence analysis to identify and map all class i and class ii transposable elements in their sequences.200819077187
persistence of entamoeba histolytica infection in cba mice owes to intestinal il-4 production and inhibition of protective ifn-gamma.the mechanisms whereby certain mouse strains develop persistent intestinal infection with entamoeba histolytica remain unclear. in this work, we characterized the kinetic pattern of cytokine responses during the course of natural infection in cba mice and showed that intracecal amebic infection led to a rapid and sustained upregulation of th2 (il-4, il-5, il-13) and th17 cytokine responses while th1 cytokines, il-12p35 and interferon (ifn)-gamma, were suppressed. depletion of il-4 cleared infect ...200819079171
innate immunity prevents tissue invasion by entamoeba histolytica.although innate and adaptive immunity both play a role in amoebiasis, the mechanisms involved in the elimination of entamoeba histolytica are poorly understood. to provide more information about the innate immune mechanisms that may confer protection against invasive amoebiasis, we administered inflammatory substances (bacillus calmette-guérin, lipopolysaccharide, complete freund's adjuvant, or mineral oil) into the peritoneum of hamsters. the animals were then challenged with pathogenic trophoz ...200819096458
the vacuolar atpase from entamoeba histolytica: molecular cloning of the gene encoding for the b subunit and subcellular localization of the protein.entamoeba histolytica is a professional phagocytic cell where the vacuolar atpase plays a key role. this enzyme is a multisubunit complex that regulates ph in many subcellular compartments, even in those that are not measurably acidic. it participates in a wide variety of cellular processes such as endocytosis, intracellular transport and membrane fusion. the presence of a vacuolar type h+-atpase in e. histolytica trophozoites has been inferred previously from inhibition assays of its activity, ...200819108705
imaging of hepatic infections.hepatic infections include pyogenic and amebic abscesses and fungal and parasitic diseases. entry of the infectious organisms into the liver can occur by hematogenous spread via the portal vein or hepatic artery, ascension of the infection from the biliary tract, or from trauma. worldwide, liver abscess is most often caused by entamoeba histolytica, but in the developed world, pyogenic liver abscess is more common. fungal infection is most often seen in immunosuppressed chemotherapy patients, wh ...200819060716
detection of entamoeba histolytica dna in the saliva of amoebic liver abscess patients who received prior treatment with metronidazole.saliva is an easily-accessible and a non-invasive clinical specimen alternate to blood and liver pus. an attempt was made to detect entamoeba histolytica dna released in the saliva of amoebic liver abscess (ala) patients by applying 16s-like rrna gene-based nested multiplex polymerase chain reaction (nm-pcr). the nm-pcr detected e. histolytica dna in the saliva of eight (28.6%) of 28 ala patients. the nm-pcr result was negative for e. histolytica dna in the saliva of all the eight ala patients w ...200819069620
prevalence of bacteria and intestinal parasites among food-handlers in gondar town, northwest ethiopia.food-handlers with poor personal hygiene working in food-service establishments could be potential sources of infection due to pathogenic organisms. the study was undertaken to determine the prevalence of bacteria and intestinal parasites among 127 food-handlers working in the cafeterias of the university of gondar and the gondar teachers training college, gondar, ethiopia. fingernail contents of both the hands and stool specimens were collected from all the 127 food-handlers. the samples were e ...200819069624
small rnas with 5'-polyphosphate termini associate with a piwi-related protein and regulate gene expression in the single-celled eukaryote entamoeba histolytica.small interfering rnas regulate gene expression in diverse biological processes, including heterochromatin formation and dna elimination, developmental regulation, and cell differentiation. in the single-celled eukaryote entamoeba histolytica, we have identified a population of small rnas of 27 nt size that (i) have 5'-polyphosphate termini, (ii) map antisense to genes, and (iii) associate with an e. histolytica piwi-related protein. whole genome microarray expression analysis revealed that esse ...200819043551
aetiology of community-acquired, acute gastroenteritis in hospitalised adults: a prospective cohort study.the aetiology of severe gastroenteritis leading to hospitalisation in adults frequently remains unclear. our objective was to study the causes and characteristics of community-acquired, acute gastroenteritis in adult hospitalized patients to support the clinical management of these patients.200818940017
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
cutaneous amebiasis in pediatrics.cutaneous amebiasis (ca), which is still a health problem in developing countries, is important to diagnose based on its clinical and histopathologic features.200818936402
first molecular identification of entamoeba moshkovskii in human stool samples in tunisia.we report the first intestinal infections in tunisia with entamoeba moshkovskii in two healthy adults. entamoeba moshkovskii cysts were distinguished from those of the morphologically identical parasites entamoeba histolytica and entamoeba dispar by specific nested polymerase chain reaction and sequencing.200818981508
three cases of intestinal capillariasis in lao people's democratic republic.capillaria philippinensis is a rare zoonotic intestinal parasite that emerged in the 1960s. the outcome of intestinal capillariasis may be fatal if untreated in due time. we report three cases of intestinal capillariasis in lao people's democratic republic (lao pdr). the three patients were unrelated previously healthy young men (24, 26, and 27 years of age) with no underlying disease or immune depression. they had chronic diarrhea, abdominal pain, edema, and severe weight loss. two of them acqu ...200818981514
an outbreak of gastroenteritis associated with intestinal parasites.intestinal protozoa are one of the leading causes of waterborne outbreaks. stool samples of 196 residents from a village of izmir, using the public water supply, were collected during an outbreak of gastroenteritis. patients were asked to fill out a questionnaire reporting on gender, age, gastrointestinal symptoms, whether or not there was a toilet in the house, their hygiene practices, and similar symptoms in the household members. of the patients who had gastrointestinal symptoms (74.5%), diar ...200818985582
[the prevalence of intestinal parasites in children brought to the kars maternal and children's hospital with complaints of gastrointestinal symptoms].this study was carried out to determine the prevalence of intestinal parasites in 2-6 year-old children who were brought to kars maternal and children's hospital with complaints of gastrointestinal symptoms during march-june 2007. fecal samples were taken from children and brought to the parasitology laboratory of the faculty of veterinary medicine to be examined for intestinal parasites. fecal samples were examined by centrifugal formalin ether, zinc-sulphate floatation, and modified acid fast ...200818985583
[the investigation of intestinal parasites in two primary schools in different social-economic districts of the city of yozgat, turkey].the aim of this study was to determine the incidence of intestinal parasites among children in two primary schools in different social-economic districts in the central region of yozgat and to educate the children about parasitic diseases. during the study, cellophane tape preparations and stool samples that had been prepared using direct mounting methods were examined. in addition the students were informed about intestinal parasites. parasitic infection was observed in 128 (34.9%) out of 367 s ...200818985585
[distribution of intestinal parasites in patients presenting at the parasitology laboratory of the medical school of erciyes university between the years of 2005 and 2008].in this study carried out from january 2005-june 2008, a total of 28,911 stool samples were examined using native-lugol and flotation/sedimentation methods and 7,164 cellophane tape preparations were examined directly. intestinal parasites were found in 6,975 (24.13%). of the patients, 52.90% were female and 47.10%, male. blastocystis hominis, 5,701 (19.72%); entamoeba coli, 910 (3.15%); giardia intestinalis, 568 (1.96%); endolimax nana, 363 (1.26%); entamoeba hartmann i, 357 (1.23%); entamoeba ...200818985586
transcriptional regulatory networks in entamoeba histolytica.expression profiling with microarray technology has revolutionized exploration of transcriptional regulatory networks on a genome-wide scale. this approach has been successfully applied to the study of entamoeba histolytica, which causes dysentery and liver abscesses and is a leading parasitic cause of death globally. a variety of microarray platforms have been developed for this system including those generated from genomic dna, long oligonucleotides, and short oligonucleotides. using these too ...200818991605
not only coughs and sneezes. 200818994670
is intestinal parasitic infection still a public health concern among saudi children?to determine the possible health risk associated with intestinal parasite infections among children with gastroenteritis in jeddah, kingdom of saudi arabia.200818998015
gigantic hepatic amebic abscess presenting as acute abdomen: a case report.amebiasis is a parasitic disease caused by entamoeba histolytica. it most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients develop intestinal invasive or extra-intestinal diseases. liver abscess is the most common extra-intestinal manifestation. the large number of clinical presentations of amebic liver abscess makes the diagnosis very challenging in non-endemic countries. late diagnosis of the amebic abscess may lead to perforation and amebic perito ...200818847505
mutation detection analysis of a region of 16s-like ribosomal rna gene of entamoeba histolytica, entamoeba dispar and entamoeba moshkovskii.the level of intra-species genetic variation in entamoeba histolytica, entamoeba dispar and entamoeba moshkovskii populations in a localized geographic area, like puducherry, india, remains unknown.200818822136
a new modified technique for concentrating intestinal parasites.the present study evaluated the diagnostic performance of a modification of the formol ethyl acetate concentration technique, with the addition of 25% acetic acid as compared with formol ethyl acetate concentration technique (fea) and fecal parasite concentrator kit fresh fecal material, free of ova and parasites, was pooled in a ratio of 1:4 with 10% buffered formalin to prepare a standardized specimen. sufficient volumes of formalin-fixed suspension of giardia lamblia cysts, entamoeba histolyt ...200818853623
cytomegalovirus colitis mimics amebic colitis in a man with aids.opportunistic gastrointestinal infections are common in patients with hiv infection; both amebic colitis and cytomegalovirus (cmv) colitis are common causes of chronic diarrhea. it is difficult to distinguish these 2 diseases by nonspecific clinical symptoms such as diarrhea, abdominal pain, and weight loss. here we report a case of cmv colitis mimicking amebic colitis with elevated indirect hemagglutination assay antibody titer against entamoeba histolytica and negative igm antibody titer again ...200818854684
thermal unfolding of triosephosphate isomerase from entamoeba histolytica: dimer dissociation leads to extensive unfolding.in mesophiles, triosephosphate isomerase (tim) is an obligated homodimer. we have previously shown that monomeric folding intermediates are common in the chemical unfolding of tim, where dissociation provides 75% of the overall conformational stability of the dimer. however, analysis of the crystallographic structure shows that, during unfolding, intermonomeric contacts contribute to only 5% of the overall increase in accessible surface area. in this work several methodologies were used to chara ...200818837510
investigation of the prevalence of amoebiasis in izmir province and determination of entamoeba spp. using pcr and enzyme immunoassay.amoebiasis is a common and life-threatening disease. the discrimination of the pathogenic entamoeba histolytica from the non-pathogenic entamoeba dispar could be done by advanced methods such as enzyme immunoassay (eia) and pcr. the aim of this study was to investigate the prevalence of amoebiasis in izmir province, and differentiate the entamoeba species by pcr and eia. stool samples of 2,047 individuals were examined by direct microscopy, formalin ethyl acetate concentration, trichrome stainin ...200818843895
entamoeba histolytica: response of the parasite to metronidazole challenge on the levels of mrna and protein expression.entamoeba histolytica remains a cause of significant morbidity and mortality in many countries. although metronidazole has been used for the treatment of amoebiasis for several decades, little is known on how the amoebae react to this challenge on the levels of mrna and protein expression. in this study, we examined their response using a focused microarray, quantitative rt-pcr, and two-dimensional gel electrophoresis (2de). the amoebae modestly increased the levels of mrna coding for superoxide ...200818845147
targets of the entamoeba histolytica transcription factor ure3-bp.the entamoeba histolytica transcription factor upstream regulatory element 3-binding protein (ure3-bp) is a calcium-responsive regulator of two e. histolytica virulence genes, hgl5 and fdx1. ure3-bp was previously identified by a yeast one-hybrid screen of e. histolytica proteins capable of binding to the sequence tattctatt (upstream regulatory element 3 (ure3)) in the promoter regions of hgl5 and fdx1. in this work, precise definition of the consensus ure3 element was performed by electrophoret ...200818846235
intestinal parasitosis among subjects undergoing cataract surgery at the eye camps in rural hilly areas of nepal.present study investigated the intestinal parasitosis among 221 subjects undergoing cataract surgery (m: 129 and f: 92; aged 13-86 years) at the eye camps in three rural hilly districts (ramechhap, sindhupalchok and dhading) in 2006. stool samples collected in clean, dry, screw capped plastic containers were examined locally by direct smear technique and anti-parasitic drugs were distributed to parasite positive subjects. the remaining stool samples were fixed with 10% formal-saline, transported ...200818828431
amebiasis.amebiasis is defined as infection with entamoeba histolytica, regardless of associated symptomatology. in resource-rich nations, this parasitic protozoan is seen primarily in travelers to and emigrants from endemic areas. infections range from asymptomatic colonization to amebic colitis and life-threatening abscesses. importantly, disease may occur months to years after exposure. although e histolytica was previously thought to infect 10% of the world's population, 2 morphologically identical bu ...200818828976
inhibitory effects of iranian thymus vulgaris extracts on in vitro growth of entamoeba histolytica.one of the most common drugs used against a wide variety of anaerobic protozoan parasites is metronidazole. however, this drug is mutagenic for bacteria and is a potent carcinogen for rodents. thymus vulgaris is used for cough suppression and relief of dyspepsia. also it has antibacterial and antifungal properties. the aim of this study was to investigate antiamebic effect of thymus vulgaris against entamoeba histolytica in comparison with metronidazole. one hundred gram air-dried t. vulgaris pl ...200818830054
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
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
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
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
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1501 - 1600 of 7191