Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
a case of probable mixed-infection with clonorchis sinensis and fasciola sp.: ct and parasitological findings.we report here a human case probably mixed-infected with clonorchis sinensis and fasciola sp. who was diagnosed by computed tomography (ct) scan, serological findings, and/or fecal examination. the patient was a 43-year-old korean female and was admitted to kyung hee university hospital with the complaints of fever and abdominal pain. on admission, marked eosinophilia was noted in her peripheral blood. ct scan showed specific lesions for clonorchiasis and fascioliasis in the liver, along with le ...201020585533
two atypical l-cysteine-regulated nadph-dependent oxidoreductases involved in redox maintenance, l-cystine and iron reduction, and metronidazole activation in the enteric protozoan entamoeba histolytica.we discovered novel catalytic activities of two atypical nadph-dependent oxidoreductases (ehno1/2) from the enteric protozoan parasite entamoeba histolytica. ehno1/2 were previously annotated as the small subunit of glutamate synthase (glutamine:2-oxoglutarate amidotransferase) based on similarity to authentic bacterial homologs. as e. histolytica lacks the large subunit of glutamate synthase, ehno1/2 were presumed to play an unknown role other than glutamine/glutamate conversion. transcriptomic ...201020592025
genomic organization of eukaryotic trnas.surprisingly little is known about the organization and distribution of trna genes and trna-related sequences on a genome-wide scale. while trna gene complements are usually reported in passing as part of genome annotation efforts, and peculiar features such as the tandem arrangements of trna gene in entamoeba histolytica have been described in some detail, systematic comparative studies are rare and mostly restricted to bacteria. we therefore set out to survey the genomic arrangement of trna ge ...201020426822
insights into entamoeba histolytica virulence modulation.entamoeba histolytica is able to invade human tissues by means of several molecules and biological properties related to the virulence. pathogenic amebas use three major virulence factors, gal/galnac lectin, amebapore and proteases, for lyse, phagocytose, kill and destroy a variety of cells and tissues in the host. responses of the parasite to host components such as mucins and bacterial flora influence the behavior of pathogenic amebas altering their expression of virulence factors. the relativ ...201020429861
recent insights in pre-mrna 3'-end processing signals and proteins in the protozoan parasite entamoeba histolytica.the messenger rna precursors (pre-mrna) 3'-end processing occurs in a two-step co-transcriptional coupled reaction, denoted as cleavage and polyadenylation. both processes depend on trans-acting factors interacting in a coordinated manner with cis-sequence motifs located at the 3' untranslated region of transcripts. in this paper, we reviewed mechanisms involved in pre-mrna processing in eukaryotic organisms, including our own findings about sequences and proteins potentially involved in mrna 3' ...201020429864
synthesis and biological activity of 2-(trifluoromethyl)-1h-benzimidazole derivatives against some protozoa and trichinella spiralis.a series of 2-(trifluoromethyl)-1h-benzimidazole derivatives (1a-1i) were synthesized via phillips cyclocondensation of a substituted 1,2-phenylenediamine and trifluoroacetic acid. the synthesized compounds were evaluated in vitro against various protozoan parasites: giardia intestinalis, entamoeba histolytica, trichomonas vaginalis and leishmania mexicana, and they showed nanomolar activities against the first three protozoa tested. the compounds were also tested in vitro and in vivo against th ...201020430484
hyperendemic h. pylori and tapeworm infections in a u.s.-mexico border population.a higher incidence of infectious disease has been documented in u.s. regions bordering mexico compared with non-border areas. we assessed the prevalence of important gastrointestinal infections in ciudad juarez, mexico, and el paso, texas, the largest binational community along the u.s.-mexico border.201020433039
bacteriological and parasitological assessment of food handlers in the omdurman area of sudan.pathogenic organisms are thought to be widely distributed among food handlers. this study was designed to assess the prevalence of carriers of some pathogenic bacteria and intestinal parasites among food handlers in the city of omdurman, sudan.201020434126
conservation and function of rab small gtpases in entamoeba: annotation of e. invadens rab and its use for the understanding of entamoeba biology.entamoeba invadens is a reptilian enteric protozoan parasite closely related to the human pathogen entamoeba histolytica and a good model organism of encystation. to understand the molecular mechanism of vesicular trafficking involved in the encystation of entamoeba, we examined the conservation of rab small gtpases between the two species. e. invadens has over 100 rab genes, similar to e. histolytica. most of the rab subfamilies are conserved between the two species, while a number of species-s ...201020434444
the tropical brown alga lobophora variegata: a source of antiprotozoal compounds.lobophora variegata, a brown alga collected from the coast of the yucatan peninsula, mexico, was studied for antiprotozoal activity against giardia intestinalis, entamoeba histolytica and trichomonas vaginalis. the whole extract showed the highest activity against t. vaginalis, with an ic(50) value of 3.2 microg/ml. for the fractions, the best antiprotozoal activity was found in non-polar fractions. the chloroform fraction of the extract contained a major sulfoquinovosyldiacylglycerol (sqdg), id ...201020479979
synthesis, characterization and biological evaluation of novel 6-ferrocenyl-4-aryl-2-substituted pyrimidine derivatives.a new series of 6-ferrocenyl-4-aryl-2-substituted pyrimidines were synthesized and evaluated for in vitro antiamoebic activity against hm1:imss strain of entamoeba histolytica. out of 16 compounds 10 compounds have shown ic(50) values in the range of 0.41-1.73 microm and 1.80 microm. pyrimidine derivatives having thiomethyl group, chloro group and mono-, di-, and trimethoxy substitution, exhibited higher antiamoebic activity than the reference drug metronidazole (ic(50)=1.80 microm). the toxicol ...201020488588
prevalence of parasitic contamination of raw vegetables in villages of qazvin province, iran.we conducted a study to determine the extent of parasitic contamination of raw vegetables distributed by wholesalers in villages of qazvin province, iran. vegetables collected for the study were leek, parsley, lettuce, coriander, radish, spring onion, tarragon, basil, spearmint, and cress. samples of each vegetable were collected at monthly intervals for 6 months from may to october 2008, yielding a total of 654 samples. samples of each vegetable collected at each monthly interval were selected ...201020491596
evaluation of a new single-tube multiprobe real-time pcr for diagnosis of entamoeba histolytica and entamoeba dispar.a single-tube multiprobe real-time pcr assay for simultaneous detection of entamoeba histolytica and entamoeba dispar was developed. one primer pair with 2 species-specific probes was designed based on new ssu rna regions of the ribosomal dna-containing episome. the sensitivity is 1 parasite per milliliter of feces and thus superior to the conventional nested pcr and comparable to other published real-time pcr protocols. the applicability for clinical diagnosis was validated with 218 stool speci ...201020496961
bioinformatic analysis of entamoeba histolytica sine1 elements.invasive amoebiasis, caused by infection with the human parasite entamoeba histolytica remains a major cause of morbidity and mortality in some less-developed countries. genetically e. histolytica exhibits a number of unusual features including having approximately 20% of its genome comprised of repetitive elements. these include a number of families of sines - non-autonomous elements which can, however, move with the help of partner lines. in many eukaryotes sine mobility has had a profound eff ...201020497534
disinfection efficacy of sodium dichloroisocyanurate (nadcc) against common food-borne intestinal protozoa.the present study was conducted to investigate the efficacy of sodium dichloroisocyanurate (nadcc) on the infective stages of common food-borne intestinal protozoa; entamoeba histolytica (e. histolytica), giardia lamblia (g. lamblia), cryptosporidium, cyclospora and microsporidia; beside its effect on raw green vegetables and fruits. parasites, isolated from stool of patients with diarrhea or dysentery, were exposed to nadcc solution (1g/l) for one and two hours. disinfection effect of nadcc was ...201020503596
detection of the endosomal sorting complex required for transport in entamoeba histolytica and characterization of the ehvps4 protein.eukaryotic endocytosis involves multivesicular bodies formation, which is driven by endosomal sorting complexes required for transport (escrt). here, we showed the presence and expression of homologous escrt genes in entamoeba histolytica. we cloned and expressed the ehvps4 gene, an escrt member, to obtain the recombinant ehvps4 and generate specific antibodies, which immunodetected ehvps4 in cytoplasm of trophozoites. bioinformatics and biochemical studies evidenced that rehvps4 is an atpase, w ...201020508821
entamoeba histolytica: differential gene expression during programmed cell death and identification of early pro- and anti-apoptotic signals.we have demonstrated that programmed cell death (pcd) in entamoeba histolytica is induced in vitro by g418 aminoglycoside antibiotic. to ascertain if biochemical and morphological changes previously observed are paired to molecular changes that reflect a genetic program, we looked here for early differential gene expression during the induction of pcd. using cdna-amplified fragment length polymorphisms (aflps) and in silico derived analysis we showed in e. histolytica a differential gene express ...201020515683
repetitive elements in parasitic protozoa.a recent paper published in bmc genomics suggests that retrotransposition may be active in the human gut parasite entamoeba histolytica. this adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity.201020529240
serum-dependent selective expression of ehtmkb1-9, a member of entamoeba histolytica b1 family of transmembrane kinases.entamoeba histolytica transmembrane kinases (ehtmks) can be grouped into six distinct families on the basis of motifs and sequences. analysis of the e. histolytica genome revealed the presence of 35 ehtmkb1 members on the basis of sequence identity (>or=95%). only six homologs were full length containing an extracellular domain, a transmembrane segment and an intracellular kinase domain. reverse transcription followed by polymerase chain reaction (rt-pcr) of the kinase domain was used to generat ...201020532220
diagnosis of amebic liver abscess and amebic colitis by detection of entamoeba histolytica dna in blood, urine, and saliva by a real-time pcr assay.the noninvasive diagnosis of amebic liver abscess is challenging, as most patients at the time of diagnosis do not have a concurrent intestinal infection with entamoeba histolytica. fecal testing for e. histolytica parasite antigen or dna is negative in most patients. a real-time pcr assay was evaluated for detection of e. histolytica dna in blood, urine, and saliva samples from amebic liver abscess as well as amebic colitis patients in bangladesh. a total of 98 amebic liver abscess and 28 amebi ...201020534800
crystal structure and trimer-monomer transition of n-terminal domain of ehcabp1 from entamoeba histolytica.ehcabp1 is a well-characterized calcium binding protein from entamoeba histolytica with four canonical ef-hand motifs. the crystal structure of ehcabp1 reveals the trimeric organization of n-terminal domain. the solution structure obtained at ph 6.0 indicated its monomeric nature, similar to that of calmodulin. recent domain-wise studies showed clearly that the n-terminal domain of ehcabp1 is capable of performing most of the functions of the full-length protein. additionally, the mode of target ...201020550906
comparison of serine-rich protein genes of entamoeba histolytica isolates obtained from institutions for the mentally retarded in kanagawa and shizuoka prefectures, japan.in japan, amebiasis has been observed in homosexual men, in institutionalized persons, and in overseas travelers. we have previously reported an outbreak of amebiasis that occurred from 1986 to 1994 in institutions for the mentally retarded in kanagawa and shizuoka prefectures in eastern japan. entamoeba histolytica but not entamoeba dispar was identified in entamoeba cultures obtained from cyst passers in four institutions located in different municipalities in this region. in the present study ...201020556425
new assembly, reannotation and analysis of the entamoeba histolytica genome reveal new genomic features and protein content information.in order to maintain genome information accurately and relevantly, original genome annotations need to be updated and evaluated regularly. manual reannotation of genomes is important as it can significantly reduce the propagation of errors and consequently diminishes the time spent on mistaken research. for this reason, after five years from the initial submission of the entamoeba histolytica draft genome publication, we have re-examined the original 23 mb assembly and the annotation of the pred ...201020559563
identification of entamoeba histolytica trophozoites in fresh stool sample: comparison of three staining techniques and study on the viability period of the trophozoites.entamoeba histolytica causes about 50 million infections worldwide with a death rate of over 100,000 annually. in endemic developing countries where resources are limited, microscopic examinations based on wheatley trichrome staining is commonly used for diagnosis of intestinal amoebiasis. other than being a time-consuming method, it must be performed promptly after stool collection as trophozoites disintegrate rapidly in faeces. the aim of this study was to compare the efficacies of eosin-y, wh ...201020562817
prevalence of entamoeba histolytica in humans.the present survey was carried out to determine the prevalence of human amebiasis. during the study, 1360 fecal samples were examined from february 2007 to december 2007 at nishtar hospital, multan. out of 1360 hosts examined, 295 were infected with e. histolytica. the overall prevalence of e. histolytica was (21.69%). relationship between sex and e. histolytica in humans showed that the infection of e. histolytica was more prevalent in male hosts (22.36%) as compared to female hosts (20.9%). ho ...201020566452
molecular identification of entamoeba spp. in captive nonhuman primates.this study describes the molecular identification of 520 entamoeba-positive fecal samples from a large and diverse population of captive nonhuman primates (nhp). the results revealed the presence of entamoeba histolytica (nhp variant only), e. dispar, e. moshkovskii, e. hartmanni, e. coli, and e. polecki-like organisms.201020573870
a phylogenetic survey of myotubularin genes of eukaryotes: distribution, protein structure, evolution, and gene expression.phosphorylated phosphatidylinositol (ptdins) lipids, produced and modified by ptdins kinases and phosphatases, are critical to the regulation of diverse cellular functions. the myotubularin ptdins-phosphate phosphatases have been well characterized in yeast and especially animals, where multiple isoforms, both catalytically active and inactive, occur. myotubularin mutations bring about disruption of cellular membrane trafficking, and in humans, disease. previous studies have suggested that myotu ...201020576132
biochemical characterization of the dna ligase i from entamoeba histolytica.dna ligases play an essential role in dna replication and repair. herein, we report the cloning and biochemical characterization of dna ligase i from the protozoan parasite entamoeba histolytica (ehdnaligi). ehdnaligi is an atp-dependent dna ligase of 685 amino acids with 35% identity to human dna ligase i. this report shows that heterologous expressed ehdnaligi is able to perform the three conserved steps of a dna ligation reaction: adenylation, binding to a 5'-phosphorylated nicked dna substra ...201020603158
synthesis and antimicrobial and nitric oxide synthase inhibitory activities of novel isothiourea derivatives.the reaction of substituted benzylhalides, or of halomethyl derivatives of thiophene or furane, with thiourea or its derivatives yielded the respective isothioureas as hydrohalide salts. the products (a total of 17, including 16 novel compounds) were tested for activity against five gram-positive and nine gram-negative bacterial strains, six yeast species and two protozoan species. the most active against gram-positive bacteria were s-(2,4-dinitrobenzyl)isothiourea hydrochloride (mic range for f ...201020607486
activity of extracts and procesterol from calotropis gigantea against entamoeba histolytica.extracts from the root bark of calotropis gigantea were subjected to bioactivity-guided fractionation using growth inhibitory effects against entamoeba histolytica. the n-hexane soluble portion of the chloroform extract showed in vitro antiamoebic activity against the hk-9 strain of entamoeba histolytica. chromatographic separation of the chloroform extract afforded the known compound, procesterol, which showed activity against e. histolytica.201020614811
human amebiasis: breaking the paradigm?for over 30 years it has been established that the entamoeba histolytica protozoan included two biologically and genetically different species, one with a pathogenic phenotype called e. histolytica and the other with a non-pathogenic phenotype called entamoeba dispar. both of these amoebae species can infect humans. e. histolytica has been considered as a potential pathogen that can cause serious damage to the large intestine (colitis, dysentery) and other extraintestinal organs, mainly the live ...201020617021
demographic and ecological effects on patterns of parasitism in eastern chimpanzees (pan troglodytes schweinfurthii) in gombe national park, tanzania.from january 2006 to january 2008, we collected 1,045 fecal samples from 90 individually-recognized, free-ranging, eastern chimpanzees (pan troglodytes schweinfurthii) inhabiting gombe national park, tanzania to determine how patterns of parasitism are affected by demographic and ecological covariates. seventeen parasite species were recovered, including eight nematodes (oesophagostomum sp., necator sp., probstmayria gombensis, strongyloides fulleborni, ascaris sp., trichuris sp., abbreviata cau ...201020623606
pyruvate:ferredoxin oxidoreductase and bifunctional aldehyde-alcohol dehydrogenase are essential for energy metabolism under oxidative stress in entamoeba histolytica.the in vitro entamoeba histolytica pyruvate:ferredoxin oxidoreductase (ehpfor) kinetic properties and the effect of oxidative stress on glycolytic pathway enzymes and fluxes in live trophozoites were evaluated. ehpfor showed a strong preference for pyruvate as substrate over other oxoacids. the enzyme was irreversibly inactivated by a long period of saturating o(2) exposure (ic(50) 0.034 mm), whereas short-term exposure (< 30 min) leading to > 90% inhibition allowed for partial restoration by ad ...201020629749
concurrent amoebic and klebsiella pneumoniae liver abscess in an immunocompetent patient: an unusual case report and review of the literature. 201020649739
the jacob2 lectin of the entamoeba histolytica cyst wall binds chitin and is polymorphic.the infectious and diagnostic form of entamoeba histolytica (eh), cause of amebic dysentery and liver abscess, is the quadranucleate cyst. the cyst wall of entamoeba invadens (ei), a model for eh, is composed of chitin fibrils and three sets of chitin-binding lectins that cross-link chitin fibrils (multivalent jacob lectins), self-aggregate (jessie lectins), and remodel chitin (chitinase). the goal here was to determine how well the ei model applies to entamoeba cysts from humans.201020652032
in memoriam: louis s. "buddy" diamond (1920-2009). 201020662997
design, synthesis, and in vitro antiprotozoal, antimycobacterial activities of n-{2-[(7-chloroquinolin-4-yl)amino]ethyl}ureas.we have synthesized a new series of quinoline tripartite hybrids from chloroquine, ethambutol, and isoxyl drugs, using a short synthetic route. compounds 1-8 were tested in vitro against five protozoa (giardia intestinalis, trichomonas vaginalis,entamoeba histolytica, leishmania mexicana and trypanosoma cruzi) and mycobacterium tuberculosis. n-(4-butoxyphenyl)-n'-{2-[(7-chloroquinolin-4-yl)amino]ethyl}urea (6) was the most active compound against all parasites tested. compound 6 was 670 times mo ...201020674375
regulation of virulence of entamoeba histolytica by the ure3-bp transcription factor.it is not understood why only some infections with entamoeba histolytica result in disease. the calcium-regulated transcription factor upstream regulatory element 3-binding protein (ure3-bp) was initially identified by virtue of its role in regulating the expression of two amebic virulence genes, the gal/galnac lectin and ferredoxin. here we tested whether this transcription factor has a broader role in regulating virulence. a comparison of in vivo to in vitro parasite gene expression demonstrat ...201020689746
identification and delineation of members of the entamoeba complex by pyrosequencing.a method using a single-round pcr coupled to pyrosequencing was developed for the detection and differentiation of members of the entamoeba complex. the technique was evaluated using dna isolated directly from faecal specimens and compared with a duplex real-time pcr targeting entamoeba histolytica and entamoeba dispar, and a conventional single-round pcr for the detection of entamoeba moshkovskii. tetranucleate cysts from 102 faecal specimens from swedish, danish and dutch patients test-positiv ...201020691255
synthesis, characterization, antiamoebic activity and cytotoxicity of novel series of pyrazoline derivatives bearing quinoline tail.the cyclization of chalcones (1a-1j) with 2-(quinolin-8-yloxy) acetohydrazide (2) under basic condition led to the formation of new compounds, pyrazoline derivatives (3a-3j). in vitro antiamoebic activity was performed against hm1: imss strain of entamoeba histolytica. the results showed that the compounds 3d, 3g, 3h, and 3j exhibited promising antiamoebic activity (ic(50) = 0.05 microm, 0.31 microm, 0.06 microm, 0.29 microm) respectively than the standard drug metronidazole (ic(50) = 1.84 micro ...201020696501
geographical location and age affects the incidence of parasitic infestations in school children.environmental factors affect the dissemination and distribution of intestinal parasites in human communities. to comprehend the prevalence of parasitic infestation and to examine whether geographical location and age also influence the prevalence of infection, fecal samples from 195 school children (rural = 95; male = 39; female = 56) (urban = 100; male = 60; female = 40) of five age groups ranging from 5 to 11 years in two different socio-economic zones (rural and urban) were screened for speci ...201020699511
a nuclear family a dna polymerase from entamoeba histolytica bypasses thymine glycol.eukaryotic family a dna polymerases are involved in mitochondrial dna replication or translesion dna synthesis. here, we present evidence that the sole family a dna polymerase from the parasite protozoan e. histolytica (ehdnapola) localizes to the nucleus and that its biochemical properties indicate that this dna polymerase may be involved in translesion dna synthesis.201020706627
evaluation of the prevalence of enterotoxigenic bacteroides fragilis and the distribution bft gene subtypes in patients with diarrhea.the aim of this study was to determine the prevalence of enterotoxigenic bacteroides fragilis (etbf) in the patients with diarrhea in our region and to assess the association between diarrhea and bft gene subtypes. the presence of etbf and bft gene subtypes were investigated in 200 stool samples from patients with diarrhea, diagnosed as gastroenteritis, which were sent to clinical microbiology laboratory at zonguldak karaelmas university, training and research hospital and in 200 stool samples f ...201020709181
a novel galacto-glycerolipid from oxalis corniculata kills entamoeba histolytica and giardia lamblia.oxalis corniculata is a naturally occurring weed that has been used in traditional medicine for the cure of dysentery and diarrhea in india. one of the common causes of dysentery is due to infection by the protist pathogen entamoeba histolytica. bioactivity profiling of extracts from o. corniculata identified several compounds that showed antiamoebic activity in axenic cultures of e. histolytica. these were characterized by nuclear magnetic resonance, infrared, and mass spectrometry as (i) oc-1, ...201020713666
dynamical organization of the cytoskeletal cortex probed by micropipette aspiration.bleb-based cell motility proceeds by the successive inflation and retraction of large spherical membrane protrusions ("blebs") coupled with substrate adhesion. in addition to their role in motility, cellular blebs constitute a remarkable illustration of the dynamical interactions between the cytoskeletal cortex and the plasma membrane. here we study the bleb-based motions of entamoeba histolytica in the constrained geometry of a micropipette. we construct a generic theoretical model that combine ...201020713731
[two cases of pulmonary amebiasis].case 1: a 74-year-old man having a week's fever and diagnosed with a liver abscess was treated with several antibiotics and percutaneous liver drainage. his respiration gradually worsened and chest computed tomography (ct) showed right pleural effusion and a left-lung mass. percutaneous fine needle aspiration of the pulmonary mass detected entamoeba histolytica. case 2: a 44-year old, zoo office worker admitted for fever and right chest pain was found in ct to have right pleural effusion and a m ...201020715559
structure-activity relationships of mononuclear metal-thiosemicarbazone complexes endowed with potent antiplasmodial and antiamoebic activities.a useful concept for the rational design of antiparasitic drug candidates is the complexation of bioactive ligands with transition metals. in view of this, an investigation was conducted into a new set of metal complexes as potential antiplasmodium and antiamoebic agents, in order to examine the importance of metallic atoms, as well as the kind of sphere of co-ordination, in these biological properties. four functionalized furyl-thiosemicarbazones (nt1-4) treated with divalent metals (cu, co, pt ...201020719524
difficulties in the treatment of intestinal amoebiasis in mentally disabled individuals at a rehabilitation institution for the intellectually impaired in japan.a mass entamoeba histolytica infection recurred despite repeated treatments with metronidazole at a rehabilitation institution for individuals with intellectual impairments.201020720419
entamoeba histolytica infection and secreted proteins proteolytically damage enteric neurons.the enteric protozoan parasite entamoeba histolytica causes amebic colitis through disruption of the mucus layer, followed by binding to and destruction of epithelial cells. however, it is not known whether ameba infections or ameba components can directly affect the enteric nervous system. analysis of mucosal innervations in the mouse model of cecal amebiasis showed that axon density was diminished to less than 25% of control. to determine whether amebas directly contributed to axon loss, we te ...201020855514
infectious colitis.purpose of review: the incidence of gastrointestinal infections continues to increase and infectious colitis contributes to significant morbidity and mortality worldwide. the purpose of this review is to highlight the recent advances in knowledge of pathogens causing infectious colitis. we describe the various pathogens and specifically focus on enterohemorrhagic escherichia coli (ehec) o157:h7, salmonella, shigella, campylobacter, and entamoeba histolytica infections, and their impact on long-t ...201020856114
classification of protein kinases on the basis of both kinase and non-kinase regions.protein phosphorylation is a generic way to regulate signal transduction pathways in all kingdoms of life. in many organisms, it is achieved by the large family of ser/thr/tyr protein kinases which are traditionally classified into groups and subfamilies on the basis of the amino acid sequence of their catalytic domains. many protein kinases are multi-domain in nature but the diversity of the accessory domains and their organization are usually not taken into account while classifying kinases in ...201020856812
the domain structure of entamoeba α-actinin2.entamoeba histolytica, a major agent of human amoebiasis, expresses two distinct forms of α-actinin, a ubiquitous actin-binding protein that is present in most eukaryotic organisms. in contrast to all metazoan α-actinins, in both isoforms the intervening rod domain that connects the n-terminal actin-binding domain with the c-terminal ef-hands is much shorter. it is suggested that these α-actinins may be involved in amoeboid motility and phagocytosis, so we cloned and characterised each domain of ...201020865366
redox regulation of udp-glucose pyrophosphorylase from entamoeba histolytica.amoebiasis is an intestinal infection caused by the human pathogen entamoeba histolytica and representing the third leading cause of death by parasites in the world. host-parasite interactions mainly involve anchored glycoconjugates localized in the surface of the parasitic cell. in protozoa, synthesis of structural oligo- and polysaccharides occurs via udp-glucose, generated in a reaction catalyzed by udp-glucose pyrophosphorylase. we report the molecular cloning of the gene coding for this enz ...201020888387
development of multiplex real-time polymerase chain reaction for detection of entamoeba histolytica, entamoeba dispar, and entamoeba moshkovskii in clinical specimens.multiplex real-time polymerase chain reaction (pcr) was developed for differential detection of entamoeba histolytica, entamoeba dispar, and entamoeba moshkovskii. specific primers were designed for all three species, and then differentiation of e. histolytica and e. dispar was achieved simultaneously using a hybridization probe and melting curve analysis, whereas e. moshkovskii was detected with a separate probe under the same condition. this assay detected as little as 0.2 pg of e. histolytica ...201020889890
seroprevalence of entamoeba histolytica infection among men who have sex with men in sydney, australia.a retrospective analysis was undertaken to determine the seroprevalence of entamoeba histolytica infection in sydney, australia. using an enzyme-linked immunosorbent assay, 429 high risk human immunodeficiency virus (hiv)-infected men who have sex with men (msm), 446 low risk hiv-uninfected msm, and 456 hiv-uninfected controls were assessed. seroprevalence rates were 5.13% for the high risk hiv-infected msm group, 0.22% for the low risk hiv-uninfected msm group, and 0.44% for the control group. ...201020889891
entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses.entamoeba histolytica calreticulin (ehcrt) is remarkably immunogenic in humans (90-100% of invasive amoebiasis patients). nevertheless, the study of calreticulin in this protozoan is still in its early stages. the exact location, biological functions, and its role in pathogenesis are yet to be fully understood. the aim of the present work is to determine the location of ehcrt in virulent trophozoites in vivo and the expression of the ehcrt gene during the development of experimentally induced am ...201020922421
comparison of protein-free defined media, and effect of l-cysteine and ascorbic acid supplementation on viability of axenic entamoeba histolytica.entamoeba histolytica is the etiologic agent for amoebiasis. the excretory-secretory (es) products of the trophozoites contain virulence factors and antigens useful for diagnostic applications. contaminants from serum supplements and dead trophozoites impede analysis of es. therefore, a protein-free medium that can sustain maximum viability of e. histolytica trophozoites for the longest time duration will enable collection of contaminant-free and higher yield of es products. in the present study ...201020922423
metabolome analysis revealed increase in s-methylcysteine and phosphatidylisopropanolamine synthesis upon l-cysteine deprivation in the anaerobic protozoan parasite entamoeba histolytica.l-cysteine is ubiquitous in all living organisms and is involved in a variety of functions, including the synthesis of iron-sulfur clusters and glutathione and the regulation of the structure, stability, and catalysis of proteins. in the protozoan parasite entamoeba histolytica, the causative agent of amebiasis, l-cysteine plays an essential role in proliferation, adherence, and defense against oxidative stress; however, the essentiality of this amino acid in the pathways it regulates is not wel ...201020923776
trend of entamoeba histolytica infestation in kolkata.abstract:201020925925
[amebiasis: implications of the recognition of entamoeba dispar and the identification of entamoeba moshkovskii in humans].the history of entamoeba histolytica is very confuse and shows several wrong concepts about the parasite and its relationship with the host. the poor correlation between the prevalence of asymptomatic and symptomatic amebiasis originated the proposal of three explicative hypothesis, among them was the concept of brumpt that e. histolytica comprised two morphologically identical species, e. dysenteriae and e. dispar. the application of modern molecular techniques irrefutably proved that e. histol ...201020928980
anti-inflammatory defense mechanisms of entamoeba histolytica.the monocyte locomotion inhibitory factor (mlif), a heat-stable oligopeptide found in the supernatant fluid of entamoeba histolytica axenic cultures, may contribute to the delayed inflammation observed in amoebic hepatic abscess. this factor was isolated by ultra-filtration and high powered liquid chromatography, obtaining a primary met-gln-cys-asn-ser structure, identified afterwards as the carboxyl-terminal (…cys-asn-ser) active site. the selective anti-inflammatory effects of the pentapeptide ...201020938711
[entamoeba histolytica]. 201020942060
ehmapk, the mitogen-activated protein kinase from entamoeba histolytica is associated with cell survival.mitogen activated protein kinases (mapks) are a class of serine/threonine kinases that regulate a number of different cellular activities including cell proliferation, differentiation, survival and even death. the pathogen entamoeba histolytica possess a single homologue of a typical mapk gene (ehmapk) whose identification was previously reported by us but its functional implications remained unexplored. ehmapk, the only mitogen-activated protein kinase from the parasitic protist entamoeba histo ...201020949043
crystal structure of the cysteine protease inhibitor 2 from entamoeba histolytica: functional convergence of a common protein fold.cysteine proteases (cp) are key pathogenesis and virulence determinants of protozoan parasites. entamoeba histolytica contains at least 50 cysteine proteases; however, only three (ehcp1, ehcp2 and ehcp5) are responsible for approximately 90% of the cysteine protease activity in this parasite. cps are expressed as inactive zymogens. because the processed proteases are potentially cytotoxic, protozoan parasites have developed mechanisms to regulate their activity. inhibitors of cysteine proteases ...201020951777
[distribution of intestinal parasites detected in the tokat public health laboratory during the period from january 2007 - december 2009].in this study, the results of 1868 stool samples and 215 cellophane tapes examined in the tokat public health laboratory between january 2007-december 2009 and the distribution of these parasites were evaluated retrospectively. a total of 1868 stool specimens from 1146 (61.3%) males and 722 (38.7%) females were examined for intestinal parasites using direct examination and the formol-ethyl acetate concentration methods. intestinal parasites were found in 40 (2.1%) females and 85 (4.6%) males. a ...201020954116
[a retrospective evaluation of the prevalence of intestinal parasites in istanbul, turkey].the aim of this study is to estimate the prevalence of intestinal parasites, in comparison to previous studies in istanbul and different geographic regions of turkey. between january 1999-december 2009, a total of 27664 stool samples from patients with suspicious intestinal parasitic infections who were admitted to istanbul university cerrahpasa medical school hospital were examined for intestinal parasites by using native lugol and formalin-ethyl acetate concentration technique, in adition to t ...201020954117
synthesis, characterization, antiamoebic activity and cytotoxicity of novel 2-(quinolin-8-yloxy) acetohydrazones and their cyclized products (1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives).a series of 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives were synthesized by the cyclization of novel 2-(quinolin-8-yloxy) acetohydrazones. in vitro antiamoebic activity was performed against hm1: imss strain of entamoeba histolytica. the results showed that all the 2-(quinolin-8-yloxy) acetohydrazones were more active than their cyclized products (1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives). sar showed that the compounds having quinoline ring and hydrazone linkage with free ...201020961670
hepato-pulmonary amebiasis: a case report.infections with entamoeba histolytica are seen worldwide and are more prevalent in the tropics. about 90% of infections are asymptomatic, and the remaining 10% produce a spectrum of clinical syndromes, ranging from dysentery to abscesses of the liver or other organs. extra-intestinal infection by e. histolytica most often involves liver. pleuro-pulmonary involvement, seen as the second most common extra-intestinal pattern of infection, is frequently associated with amebic liver abscess. pulmonar ...201020963322
dynamic instability of the intracellular pressure drives bleb-based motility.we have demonstrated that the two- and three-dimensional motility of the human pathogenic parasite entamoeba histolytica (eh) depends on sustained instability of the intracellular hydrostatic pressure. this instability drives the cyclic generation and healing of membrane blebs, with typical protrusion velocities of 10-20 μm/second over a few hundred milliseconds and healing times of 10 seconds. the use of a novel micro-electroporation method to control the intracellular pressure enabled us to de ...201020980385
application of real-time polymerase chain reaction in detection of entamoeba histolytica in pus aspirates of liver abscess patients.entamoeba histolytica is the second major cause of liver abscess disease in humans, particularly in developing countries. recently, dna molecular-based methods have been employed to enhance the detection of e. histolytica in either pus or stool specimens. in this study, the results of real-time polymerase chain reaction (pcr) to detect e. histolytica dna in pus from liver abscess cases were compared with those of indirect hemagglutination assay on the corresponding serum samples. bacterial cultu ...201020132028
entamoeba histolytica: expression and localization of gal/galnac lectin in virulent and non-virulent variants from hm1:imss strain.we have purified gal/galnac lectin from entamoeba histolytica by electroelution. the purified protein was used to immunize rabbits and obtain polyclonal igg's anti-lectin. these antibodies were used as tools to analyze the expression and localization of the amoebic lectin in both virulent (veh) and non-virulent (nveh) variants of axenically cultured hm1:imss strain. veh is able to induce liver abscesses in hamsters, whereas nveh has lost this ability. in vitro, amoebic trophozoites from both var ...201020138867
entamoeba histolytica: molecular cloning and characterization of a novel neutral sphingomyelinase.a novel neutral sphingomyelinase (nsmase) was characterized in entamoeba histolytica trophozoites. smase, a sphingomyelin-specific form of phospholipase c, catalyzes the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. three amebic putative nsmase genes were found to be actively transcribed. mg(2+)-independent nsmase activity in the soluble fraction of the trophozoites was stimulated by mn(2+) and partially inhibited by zn(2+). nsmase activity of the recombinant protein ehnsm1, inc ...201020138872
effect of the monocyte locomotion inhibitory factor (mlif) produced by e. histolityca on cytokines and chemokine receptors in t cd4+ lymphocytes.entamoeba histolytica produces monocyte locomotion inhibitory factor (mlif), which may contribute to the delayed inflammation observed in amoebic hepatic abscesses. leukocytes are affected through the modulation of cytokine expression and/or production. we evaluated the effects of mlif on the activation and production of intracellular cytokines in human cd4+ t lymphocytes by flow cytometry. cells were stimulated for 24 h with pma, mlif, or pma+mlif. cellular activation was measured using anti-cd ...201020140297
microbicidal effect of the lactoferrin peptides lactoferricin17-30, lactoferrampin265-284, and lactoferrin chimera on the parasite entamoeba histolytica.entamoeba histolytica is a parasitic protozoan that produces amoebiasis, an intestinal disease characterized by ulcerative colitis and dysentery. in some cases, trophozoites can travel to the liver leading to hepatic abscesses and death. recently, lactoferrin and lactoferricin b have been shown to be amoebicidal in axenic cultures. the aim of this work was to determine whether the lactoferrin-peptides lactoferricin amino acids 17-30, lactoferrampin amino acids 265-284, and lactoferrin chimera wh ...201020140481
intestinal protozoa infections among patients with ulcerative colitis: prevalence and impact on clinical disease course.epidemiological and microbiologic studies suggest that enteropathogenic microorganisms play a substantial role in the clinical initiation and relapses of inflammatory bowel disease.201020145404
the role of lipopeptidophosphoglycan in the immune response to entamoeba histolytica.the sensing of pathogen associated molecular patterns (pamps) by innate immune receptors, such as toll-like receptors (tlrs), is the first step in the inflammatory response to pathogens. entamoeba histolytica, the etiological agent of amebiasis, has a surface molecule with the characteristics of a pamp. this molecule, which was termed lipopeptidophosphoglycan (lppg), is recognized through tlr2 and tlr4 and leads to the release of cytokines from human monocytes, macrophages, and dendritic cells; ...201020145703
amoebiasis cutis: clinical suspicion is the key to early diagnosis.amoebiasis cutis is a rare manifestation of entamoeba histolytica, primarily an intestinal pathogen, which occurs as a complication of amoebic dysentery. primary cutaneous amoebiasis occurs from contamination of pre-existing wounds. a high degree of clinical suspicion and demonstration of trophozoites from lesions are important for making an early diagnosis lest these patients should suffer significant morbidity. a hiv-negative and otherwise healthy 40-year-old man presented with a well-defined, ...201020148845
entamoeba histolytica sirtuin ehsir2a deacetylates tubulin and regulates the number of microtubular assemblies during the cell cycle.we have discovered four sirtuin genes in entamoeba histolytica, two of which are similar to eukaryotic sirtuins and two to bacterial and archaeal sirtuins. the eukaryotic sirtuin homologue, ehsir2a, showed nad(+)-dependent deacetylase activity and was sensitive to class iii hdac inhibitors. localization of ehsir2a at different cellular sites suggested that this deacetylase could have multiple targets. using an e. histolytica cdna library in the yeast two-hybrid genetic screen, we identified seve ...201020148900
u12 type introns were lost at multiple occasions during evolution.two categories of introns are known, a common u2 type and a rare u12 type. these two types of introns are removed by distinct spliceosomes. the phylogenetic distribution of spliceosomal rnas that are characteristic of the u12 spliceosome, i.e. the u11, u12, u4atac and u6atac rnas, suggest that u12 spliceosomes were lost in many phylogenetic groups. we have now examined the distribution of u2 and u12 introns in many of these groups.201020149226
seroprevalence of entamoeba histolytica in the context of hiv and aids: the case of vhembe district, in south africa's limpopo province.in a recent study in northern south africa, the seroprevalence of entamoeba histolytica infection among 257 hiv-positive and 117 hiv-negative individuals was determined, using an elisa for the detection of antibodies reacting with the parasite's galactose/-acetyl-d-galactosamine(gal/galnac)-inhibitable adherence lectin. overall, 34.0% of the 374 participants (36.1% of the females and 28.1% of the males) were found seropositive for e. histolytica. although all age-groups were affected by the amoe ...201020149292
the r2r3 myb protein family in entamoeba histolytica.the myb dna-binding domain is conserved in vertebrates, plants, and fungi. this domain mediates the dna-binding activity of proteins (that have transcription factor activity) in a sequence-specific manner and is also used for the protection of telomeric regions. the myb dna-binding domain contains three imperfect conserved repeats of 52 amino acids (r1, r2, and r3). within each repeat, there are three tryptophans that are separated by 18 or 19 amino acids. in order to understand the role of myb ...201020156532
in vitro induction of entamoeba histolytica cyst-like structures from trophozoites.inhibition of encystment can be conceived as a potentially useful mechanism to block the transmission of entamoeba histolytica under natural conditions. unfortunately, amoeba encystment has not been achieved in vitro and drugs inhibiting the formation of cysts are not available. luminal conditions inducing encystment in vivo are also unknown, but cellular stress such as exposure to reactive oxygen species from immune cells or intestinal microbiota could be involved. a role for certain divalent c ...201020169067
differential identification of entamoeba spp. based on the analysis of 18s rrna.entamoeba histolytica is known to cause intestinal and extra-intestinal disease while the other entamoeba species are not considered to be pathogenic. however, all entamoeba spp. should be reported when identified in clinical samples. entamoeba polecki, entamoeba coli, and entamoeba hartmanii can be differentiated morphologically from e. histolytica, but some of their diagnostic morphologic features overlap. e. histolytica, entamoeba dispar, and entamoeba moshkovskii are morphologically identica ...201020169364
a new nuclear function of the entamoeba histolytica glycolytic enzyme enolase: the metabolic regulation of cytosine-5 methyltransferase 2 (dnmt2) activity.cytosine-5 methyltransferases of the dnmt2 family function as dna and trna methyltransferases. insight into the role and biological significance of dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. in this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a dnmt2-binding protein. enolase, which is known to catalyze the conversion of 2-phosphoglycerate (2-pg) to phosphoenolpyruvate (pep), was shown to h ...201020174608
dyspnea and dysentery: a case report of pleuropulmonary amebiasis.pleuropulmonary amebiasis is an uncommon complication of entamoeba histolytica infection. it typically occurs in endemic regions including central and south america, africa and the indian subcontinent. the case of a previously healthy us army male stationed in liberia with an acute onset of fevers, abdominal pain and bloody diarrhea is presented. he developed a productive cough with pleuritic chest pain and imaging revealed multiple liver abscesses, with rupture through the diaphragm causing a l ...201020175253
entamoeba histolytica phosphoserine aminotransferase (ehpsat): insights into the structure-function relationship.abstract:201020199659
epizootic fatal amebiasis in an outdoor group of old world monkeys.entamoeba (e.) histolytica is an obligate parasite of humans and non-human primates.201020202078
regulation of gene expression in protozoa parasites.infections with protozoa parasites are associated with high burdens of morbidity and mortality across the developing world. despite extensive efforts to control the transmission of these parasites, the spread of populations resistant to drugs and the lack of effective vaccines against them contribute to their persistence as major public health problems. parasites should perform a strict control on the expression of genes involved in their pathogenicity, differentiation, immune evasion, or drug r ...201020204171
hydrogen peroxide-induced apoptosis-like cell death in entamoeba histolytica.the microaerophilic intestinal parasitic protozoan entamoeba histolytica has been previously shown to be highly susceptible to oxidative stress induced by hydrogen peroxide. however the mechanism of cell death was not investigated. studies presented in this paper demonstrate several morphological features in the parasite when exposed to h(2)o(2) which are identical to metazoan apoptotic phenotype indicating a possible apoptosis-like cell death exhibited by e. histolytica in response to h(2)o(2) ...201020079879
members of the entamoeba histolytica transmembrane kinase family play non-redundant roles in growth and phagocytosis.entamoeba histolytica contains a large and novel family of transmembrane kinases (tmks). the expression patterns of the e. histolytica tmks in individual trophozoites and the roles of the tmks for sensing and responding to extracellular cues were incompletely characterised. here we provide evidence that single cells express multiple tmks and that tmk39 and tmk54 likely serve non-redundant cellular functions. laser-capture microdissection was used in conjunction with microarray analysis to demons ...201020083116
acetate formation in the energy metabolism of parasitic helminths and protists.formation and excretion of acetate as a metabolic end product of energy metabolism occurs in many protist and helminth parasites, such as the parasitic helminths fasciola hepatica, haemonchus contortus and ascaris suum, and the protist parasites, giardia lamblia, entamoeba histolytica, trichomonas vaginalis as well as trypanosoma and leishmania spp. in all of these parasites acetate is a main end product of their energy metabolism, whereas acetate formation does not occur in their mammalian host ...201020085767
freezing of stool samples improves real-time pcr detection of entamoeba dispar and entamoeba histolytica.pcr as a tool for intestinal parasite diagnosis is expanding since differentiation between entamoeba histolytica and entamoeba dispar cysts is impossible with microscopy. since pre-analytical factors influence dna detection, we evaluated with real-time pcr the influence of storage time and temperature. we demonstrated an improved dna detection in frozen stool samples.201020085792
the nf-kappab p50 subunit is protective during intestinal entamoeba histolytica infection of 129 and c57bl/6 mice.entamoeba histolytica is the agent of amebic colitis. in this work we examined the intestinal nf-kappab response to this parasite. using an enzyme-linked immunosorbent assay (elisa) and an electrophoretic mobility shift assay, we found that the nf-kappab subunit p50 predominated in nuclear extracts of whole cecal tissue and of isolated crypts from mice inoculated with e. histolytica. p50 was protective, since c57bl/6 and 129 mice in which there was targeted deletion of this subunit were more sus ...201020086086
prevalence and spatial distribution of entamoeba histolytica/dispar and giardia lamblia among schoolchildren in agboville area (côte d'ivoire).new efforts are being made to improve understanding of the epidemiology of the helminths and intensifying the control efforts against these parasites. in contrast, relatively few studies are being carried out in this direction for the intestinal protozoa. to contribute to a better comprehension of the epidemiology of the intestinal protozoa, prevalence, and spatial distribution of entamoeba histolytica/dispar and giardia lamblia, and their association with drinking water supplies, were determine ...201020087416
epithelial cell apoptosis facilitates entamoeba histolytica infection in the gut.entamoeba histolytica is the protozoan parasite that causes amebic colitis. the parasite triggers apoptosis on contact with host cells; however, the biological significance of this event during intestinal infection is unclear. we examined the role of apoptosis in a mouse model of intestinal amebiasis. histopathology revealed that abundant epithelial cell apoptosis occurred in the vicinity of amoeba in histological specimens. epithelial cell apoptosis occurred rapidly on co-culture with amoeba in ...201020093500
biochemical and structural properties of chimeras constructed by exchange of cofactor-binding domains in alcohol dehydrogenases from thermophilic and mesophilic microorganisms.the cofactor-binding domains (residues 153-295) of the alcohol dehydrogenases from the thermophile thermoanaerobacter brockii (tbadh), the mesophilic bacterium clostridium beijerinckii (cbadh), and the protozoan parasite entamoeba histolytica (ehadh1) have been exchanged. three chimeras have been constructed. in the first chimera, the cofactor-binding domain of thermophilic tbadh was replaced with the cofactor-binding domain of its mesophilic counterpart cbadh [chimera chi21((tct))]. this domain ...201020102159
differences in the transcriptome signatures of two genetically related entamoeba histolytica cell lines derived from the same isolate with different pathogenic properties.the availability of two genetically very similar cell lines (a and b) derived from the laboratory isolate entamoeba histolytica hm-1:imss, which differ in their virulence properties, provides a powerful tool for identifying pathogenicity factors of the causative agent of human amoebiasis. cell line a is incapable inducing liver abscesses in gerbils, whereas interaction with cell line b leads to considerable abscess formation. phenotypic characterization of both cell lines revealed that trophozoi ...201020102605
vanadium complexes having [v(iv)o](2+) and [v(v)o(2)](+) cores with binucleating dibasic tetradentate ligands: synthesis, characterization, catalytic and antiamoebic activities.binucleating hydrazones ch(2)(h(2)sal-bhz)(2) (i) and ch(2)(h(2)sal-fah)(2) (ii), derived from 5,5'-methylbis(salicylaldehyde) and benzoylhydrazide or 2-furoylhydrazide, react with [v(iv)o(acac)(2)] to give dinuclear v(iv)o-complexes [ch(2){v(iv)o(sal-bhz)(h(2)o)}(2)] 1 and [ch(2){v(iv)o(sal-fah)(h(2)o)}(2)] 4, respectively. in the presence of koh or csoh.h(2)o, oxidation of 1 and 2 results in the formation of dioxidovanadium(v) complexes, k(2)[ch(2){v(v)o(2)(sal-bhz)}(2)].2h(2)o 2, k(2)[ch(2){v ...201020104362
new dioxazole derivatives: synthesis and effects on the growth of entamoeba histolytica and giardia intestinalis.cyclization of oxime with different aldehydes and ketones under basic condition led to the formation of new dioxazole derivatives and the structure was elucidated by spectral data. the effects of diaoxazoles on the inhibition of growth of entamoeba histolytica and giardia intestinalis in vitro have been determined, and selected compounds further investigated for their toxicity. sar showed that the compounds with 5-nitrothiophene group at the 3-postion of the diaoxazole ring were more active than ...201020122767
pyogenic versus amoebic liver abscesses. a comparative clinical study in a series of 58 patients.to compare the clinical and epidemiological characteristics of patients with pyogenic liver abscess (pla) and with amebic liver abscess (aha) in order to determine the potential factors that may help improve diagnosis and treatment for this disease.201020361845
Refresh
firstprev
...51525354555657585960...
nextlast
Displaying items 5901 - 6000 of 7191