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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
[the lytic action of normal faeces on the vegetative form of entamoeba histolytica]. 194620985983
the detection of the cysts of entamoeba histolytica in the faeces by microscopic examination. 194620991500
improved egg yolk infusion for cultivation of entamoeba histolytica and other intestinal protozoa. 194620993483
migration of endamoeba histolytica on solid media. 194620996732
the experimental infection of rats with entamoeba histolytica; with a method for evaluating the anti-amoebic properties of new compounds. 194620997895
complement fixation antigen in entamoeba histolytica infection. 194521004024
guide to the laboratory diagnosis of entamoeba histolytica. 194521004199
carriers of entamoeba histolytica in africans of northern rhodesia. 194521004878
supernucleate cysts of endamoeba coli and e. histolytica. 194521006498
studies on entamoeba histolytica; the relation of oxidation-reduction potentials to the growth, encystation and excystation of entamoeba histolytica in culture. 194621014256
a copper sulphate flotation method for the examination of e. histolytica cysts. 194521026570
the use of dehydrated, coagulated egg yolk in the preparation of a medium for culturing endamoeba histolytica. 194621027509
functional cytology of entamoeba histolytica. 194621027510
amebic liver abscess. 201021036819
acute amebic appendicitis: report of a rare case.acute appendicitis of amebic origin is considered a rare cause of acute appendicitis. we report a case of amebic appendicitis presenting with fever, severe pain in the right lower quadrant of the abdomen and rebound tenderness. lab investigations revealed neutrophilic leukocytosis. the patient underwent appendectomy. histopathological examination revealed numerous entameba histolytica trophozoites in the mucosa of the appendix. acute appendicitis of amebic origin does not appear frequently. appe ...201021045411
[evolution of the prevalence the enteroparasitoses in talca-chile].the prevalence of intestinal parasites in preschool and school children in the city of talca and rural areas belonging to the maule region, was assessed annually by means of the serial parasitological studies in stool which were performed in the parasitology laboratory of the "universidad de talca". for consecutive periods since 1980 until 2008, an estimated prevalence of parasitism of 76.2% in the population studied was found. these results show a marked decrease from 9.8% to 2.5% in pathogenic ...201021046719
evaluation of multiplex tandem real-time pcr for detection of cryptosporidium spp., dientamoeba fragilis, entamoeba histolytica, and giardia intestinalis in clinical stool samples.the aim of this study was to describe the first development and evaluation of a multiplex tandem pcr (mt-pcr) assay for the detection and identification of 4 common pathogenic protozoan parasites, cryptosporidium spp., dientamoeba fragilis, entamoeba histolytica, and giardia intestinalis, from human clinical samples. a total of 472 fecal samples submitted to the department of microbiology at st. vincent's hospital were included in the study. the mt-pcr assay was compared to four real-time pcr (r ...201021048004
in vitro trna methylation assay with the entamoeba histolytica dna and trna methyltransferase dnmt2 (ehmeth) enzyme.protozoan parasites are among the most devastating infectious agents of humans responsible for a variety of diseases including amebiasis, which is one of the three most common causes of death from parasitic disease. the agent of amebiasis is the amoeba parasite entamoeba histolytica that exists under two stages: the infective cyst found in food or water and the invasive trophozoite living in the intestine. the clinical manifestations of amebiasis range from being asymptomatic to colitis, dysente ...201021048666
synthesis, characterization, antiamoebic activity and cytotoxicity of new pyrazolo[3, 4-d]pyrimidine-6-one derivatives.a new series of pyrazolo[3,4-d]pyrimidine-6-one derivatives (2a-2j) were prepared by using the biginelli multicomponent cyclocondensation of 3-methyl-1-phenyl-1h-pyrazol-5(4h)-one (1a), different aromatic aldehydes, and urea with a catalytic amount of hcl at reflux temperature. these compounds were characterized by ir, (1)h nmr, (13)c nmr, and mass spectral data. in vitro antiamoebic activity was performed against hm1:imss strain of entamoeba histolytica. the results showed that the compounds 2b ...201021054147
[adaptation of a sensitive dna extraction method for detection of entamoeba histolytica by real-time polymerase chain reaction.]this study was aimed to adapt a sensitive dna extraction protocol in stool samples for real-time polymerase chain reaction (pcr) detection of entamoeba histolytica which causes important morbidity and mortality worldwide. stool extraction is a problematic step and has direct effects on pcr sensitivity. in order to improve the sensitivity of e.histolytica detection by real-time pcr, "qiaamp dna stool minikit (qiagen, germany)" was modified by adding an overnight incubation step with proteinase k ...201021063995
growth requirements of endameba histolytica. 194621064309
the nucleus of entamoeba histolytica in action. 194621066140
observations on the growth of entamoeba histolytica. 194621066202
prevalence of intestinal parasites among school children in northern districts of west bank-palestine.to assess the prevalence of intestinal parasite infections in northern districts of west bank, palestine and to determine associated sociodemographic factors.201021073639
epidermal cyst infected by entamoeba histolytica in a patient with no past history of intestinal amebiasis. 201021091686
cd4+ and cd8+ t cell- and il-17-mediated protection against entamoeba histolytica induced by a recombinant vaccine.amebiasis in the murine model can be prevented by vaccination with the gal/galnac lectin through a t cell-dependent mechanism. in this work we further decipher the mechanism of this protection. mice vaccinated with the recombinant "leca" fragment of the gal/galnac lectin with alum were capable of transferring protection to naïve recipients by both cd4+ t cells and surprisingly cd8+ t cells. we then examined the cytokine profile of these cells. cd4+ t cells from pbmc of leca-alum vaccinated mice ...201021095257
calmodulin-like protein from entamoeba histolytica: solution structure and calcium-binding properties of a partially folded protein.the mechanism of ca(2+)-signaling in the protozoan parasite entamoeba histolytica is yet to be understood as many of the key regulators are still to be identified. e. histolytica encodes a number of multi-ef-hand ca(2+)-binding proteins (ehcabps). functionally only one of these molecules, ehcabp1, has been characterized to date. the calmodulin-like protein from e. histolytica (abbreviated as ehcam or ehcabp3) is a 17.23 kda monomeric protein that shows maximum sequence identity with heterologous ...201021114322
n-acetyl-d-glucosaminylphosphatidylinositol de-n-acetylase from entamoeba histolytica: metal alters catalytic rates but not substrate affinity.pig-l/gpi12 proteins are endoplasmic reticulum-resident membrane proteins involved in the second step of glycosylphosphatidylinositol anchor biosynthesis in eukaryotes. we show that the entamoeba histolytica pig-l protein is optimally active in the acidic ph range. the enzyme has an intrinsic low level of de-n-acetylase activity in the absence of metal and is significantly stimulated by divalent cations. metal binding induces a large conformational change in the protein that appears to improve c ...201021118807
leptin signaling in intestinal epithelium mediates resistance to enteric infection by entamoeba histolytica.leptin is an adipocytokine that links nutrition to immunity. previous observation that a genetic polymorphism in the leptin receptor affected susceptibility to entamoeba histolytica infection led to the hypothesis that leptin signaling has a protective role during intestinal amebic infection. in this study we show that mice lacking the functional leptin receptor developed devastating mucosal destruction after e. histolytica infection. bone marrow chimera experiments demonstrated that leptin rece ...201021124310
entamoeba histolytica secretes two haem-binding proteins to scavenge haem.entamoeba histolytica is a human pathogen which can grow using different sources of iron such as free iron, lactoferrin, transferrin, ferritin or haemoglobin. in the present study, we found that e. histolytica was also capable of supporting its growth in the presence of haem as the sole iron supply. in addition, when trophozoites were maintained in cultures supplemented with haemoglobin as the only iron source, the haem was released and thus it was introduced into cells. interestingly, the ehhmb ...201121126234
expression of cytokines and their regulation during amoebic liver abscess development.amoebic liver abscess (ala) is the most important extraintestinal complication of entamoeba histolytica infection. amoebic liver abscess development causes severe destruction of the liver tissue concomitant with a strong inflammatory reaction. we analyse the in situ expression of tnf-α, ifn-γ, il-1β, 1l-8 and il-10 at different stages of ala development in a susceptible animal model. results showed that after inoculation, neutrophils (pmn) and some macrophages infiltrated the liver and were posi ...201121155843
biophysical characterization of entamoeba histolytica phosphoserine aminotransferase (ehpsat): role of cofactor and domains in stability and subunit assembly.we investigated the role of the cofactor plp and its binding domain in stability and subunit assembly of phosphoserine aminotransferase (ehpsat) from an enteric human parasite entamoeba histolytica. presence of cofactor influences the tertiary structure of ehpsat because of the significant differences in the tryptophan microenvironment and proteolytic pattern of holo- and apo-enzyme. however, the cofactor does not influence the secondary structure of the enzyme. stability of the protein is signi ...201021161522
rna interference in entamoeba histolytica: implications for parasite biology and gene silencing.entamoeba histolytica is a major health threat to people in developing countries, where it causes invasive diarrhea and liver abscesses. the study of this important human pathogen has been hindered by a lack of tools for genetic manipulation. recently, a number of genetic approaches based on variations of the rnai method have been successfully developed and cloning of endogenous small-interfering rnas from e. histolytica revealed an abundant population of small rnas with an unusual 5´-polyphosph ...201121162639
effect of phosphatidylcholine-cholesterol liposomes on entamoeba histolytica virulence.trophozoites of entamoeba histolytica hm-1:imss become less virulent after long-term maintenance in axenic cultures. the factors responsible for the loss of virulence during in vitro cultivation remain unclear. however, it is known that in vitro cultivation of amoeba in culture medium supplemented with cholesterol restores their virulence. in this study, we analyzed the effect of adding phosphatidylcholine-cholesterol (pc-chol) liposomes to the culture medium and evaluated the effect of this lip ...201021164568
amoebic abscess of the spleen and fatal colonic perforation. 201121173680
epidemiology and control of schistosomiasis and other intestinal parasitic infections among school children in three rural villages of south saint lucia.the purpose of this study was to determine the epidemiology of parasitic infections and the efficacy of treatment among school children in rural villages of south saint lucia.201021178216
development of a negative selectable marker for entamoeba histolytica.entamoeba histolytica is the causative agent of amebiasis and infects up to 10% of the world's population. the molecular techniques that have enabled the up- and down-regulation of gene expression rely on the transfection of stably maintained plasmids. while these have increased our understanding of entamoeba virulence factors, the capacity to integrate exogenous dna into genome, which would allow reverse genetics experiments, would be a significant advantage in the study of this parasite. the c ...201021189470
3d active meshes: fast discrete deformable models for cell tracking in 3d time-lapse microscopy.variational deformable models have proven over the past decades a high efficiency for segmentation and tracking in 2d sequences. yet, their application to 3d time-lapse images has been hampered by discretization issues, heavy computational loads and lack of proper user visualization and interaction, limiting their use for routine analysis of large data-sets. we propose here to address these limitations by reformulating the problem entirely in the discrete domain using 3d active meshes, which exp ...201021193379
intestinal parasites in immigrants in the city of naples (southern italy).the present study was aimed at carrying out a cross-sectional copromicroscopic survey of helminths and intestinal protozoa in immigrants in naples (southern italy). between october 2008 and november 2009, a total of 514 immigrants were tested comparing the flotac dual technique and the ethyl acetate concentration technique. combined results of the two techniques served as a diagnostic 'gold' standard and revealed an overall prevalence of parasitic infections of 61.9% (318/514). the ethyl acetate ...201021195044
epigenetics in the unicellular parasite entamoeba histolytica.amoebiasis is a serious infectious disease that is caused by the unicellular parasite, entamoeba histolytica. this parasite is mainly found in developing countries, and are named owing to its ability to destroy tissues. the molecular mechanisms that regulate the virulence of this parasite are not well understood. in recent years, an increasing interest in the epigenetic regulation of the parasite's virulence has emerged. in this article, an overview of our current knowledge about the role of dna ...201021198420
myeloperoxidase binds to and kills entamoeba histolytica trophozoites.during amebic invasion, neutrophils are a key component in either protecting against invading trophozoites or contributing to tissue damage. upon degranulating or being lysed, neutrophils release toxic substances that can kill amebas as well as damage host tissue. in a previous study we identified a protein from nonspecifically stimulated peritoneal exudates of hamster that has peroxidase and marked amebicidal activity. in the current study we analyzed the in vitro amebicidal effect of purified ...201121204853
amebiasis among persons who sought voluntary counseling and testing for human immunodeficiency virus infection: a case-control study.this case-control study aimed to characterize the factors associated with amebiasis, defined as presence of anti-entamoeba histolytica antibody titers of ≧ 128 by indirect hemagglutination assay, among persons seeking voluntary counseling and testing (vct) for human immunodeficiency virus (hiv) infection. between april 2006 and september 2009, 57 of 4,802 persons (1.2%) seeking vct services were seropositive for e. histolytica infection. compared with 228 seronegative controls, case subjects wer ...201121212204
involvement of src family tyrosine kinase in apoptosis of human neutrophils induced by protozoan parasite entamoeba histolytica.tyrosine kinases are one of the most important regulators for intracellular signal transduction related to inflammatory responses. however, there are no reports describing the effects of tyrosine kinases on neutrophil apoptosis induced by entamoeba histolytica. in this study, isolated human neutrophils from peripheral blood were incubated with live trophozoites in the presence or absence of tyrosine kinase inhibitors. entamoeba-induced receptor shedding of cd16 and ps externalization in neutroph ...201021234229
site-specific free energy changes in proteins upon ligand binding by nuclear magnetic resonance: ca2+ -displacement by ln3+ in a ca2+ -binding protein from entamoeba histolytica.the study of protein-ligand interaction has been of a great interest in contemporary structural biology. the understanding of the nature of such interaction and determining the associated binding affinities are of utmost importance. nuclear magnetic resonance has become a powerful tool in deriving information related to such interactions in proteins. nuclear magnetic resonance data provide the site-specific information even in the case of proteins having multiple-binding sites and populations of ...201121235730
frequency of intestinal parasitic infection among children in hadhramout governorate (yemen).six hundred children from urban and rural regions of hadhramout governorate were examined targeted for the detection of intestinal parasites during the year 2009. the main infective parasites prevailed in children were gardia lamblia (19.17%), entamoeba histolytica (16.83%), ascaris lumbricoides (15.83%), trichuris trichiura (2.33%), hymenolepis nana (2.33%), taenia saginata (1.50%) and schistosoma mansoni (0.67%). besides, infections were accompanied by different symptoms as diarrhea (43.5%), a ...201021246955
crystal structures of three protozoan homologs of tryptophanyl-trna synthetase.tryptophanyl-trna synthetase (trprs) is an essential enzyme that is recognizably conserved across all forms of life. it is responsible for activating and attaching tryptophan to a cognate trna(trp) molecule for use in protein synthesis. in some eukaryotes this original core function has been supplemented or modified through the addition of extra domains or the expression of variant trprs isoforms. the three trprs structures from pathogenic protozoa described here represent three illustrations of ...201121255615
intestinal parasites infections in hospitalized aids patients in kinshasa, democratic republic of congo.to determine the prevalence and the species spectrum of intestinal parasites (ip) involved in hospitalized aids patients, a prospective observational and cross-sectional study was carried out in the four main hospitals in kinshasa, democratic republic of the congo. from november 2006 through september 2007, a single stool sample was collected from 175 hospitalized aids patients older than 15 years. parasites were detected by light microscopy, including ziehl-neelsen, fungi-fluor, modified trichr ...201021275238
the epidemiology of soil-transmitted helminth and protozoan infections in south-west cameroon.a cross-sectional study of the prevalence, intensity and effects of soil-transmitted helminth and protozoan infections was undertaken among patients at the buea hospital annex located in buea sub-division of cameroon. stool samples from 356 subjects (174 males and 182 females) were collected and processed using standard concentration methods. our results showed that 31.0% of subjects were infected with intestinal helminths and the prevalence was higher in females (32.4%) than in males (30.5%). a ...201121281528
different structure and mrna expression of entamoeba invadens chitinases in the encystation and excystation.entamoeba histolytica forms chitin-walled cysts during encystation process, where formation of the cyst wall needs not only chitin synthase but also chitinase. during excystation, quadruplet amoebae emerge from the chitin-walled cysts by dissolving the wall, so that chitinase may be necessary for excystation process as well. there is, however, no report on chitinase expression during excystation. in this study, we used entamoeba invadens, a reptilian amoeba, as a model for encystation and excyst ...201121286750
evolutionary genomics of entamoeba.entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. understanding the genome and evolution of the parasite will help explain how, when and why it causes disease. here we review current knowledge about the evolutionary genomics of entamoeba: how differences between the genomes of different species may help explain different phenotypes, and how variation among e. histolytica parasites reveals patterns of population str ...201121288488
high throughput multiplex pcr and probe-based detection with luminex beads for seven intestinal parasites.polymerase chain reaction (pcr) assays for intestinal parasites are increasingly being used on fecal dna samples for enhanced specificity and sensitivity of detection. comparison of these tests against microscopy and copro-antigen detection has been favorable, and substitution of pcr-based assays for the ova and parasite stool examination is a foreseeable goal for the near future. one challenge is the diverse list of protozoan and helminth parasites. several existing real-time pcr assays for the ...201121292910
structural and biochemical studies of serine acetyltransferase reveal why the parasite entamoeba histolytica cannot form a cysteine synthase complex.cysteine (cys) plays a major role in growth and survival of the human parasite entamoeba histolytica. we report here the crystal structure of serine acetyltransferase (sat) isoform 1, a cysteine biosynthetic pathway enzyme from e. histolytica (ehsat1) at 1.77 å, in complex with its substrate serine (ser) at 1.59 å and inhibitor cys at 1.78 å resolution. ehsat1 exists as a trimer both in solution as well as in crystal structure, unlike hexamers formed by other known sats. the difference in oligom ...201121297164
a case of liver abscess (entamœba histolytica) treated by open operation and emetine. 193221312757
entamoeba histolytica: biochemical characterization of a protein disulfide isomerase.protein disulfide isomerase (pdi) enzymes are eukaryotic oxidoreductases that catalyze oxidation, reduction and isomerization of disulfide bonds in polypeptide substrates. here, we report the biochemical characterization of a pdi enzyme from the protozoan parasite entamoeba histolytica (ehpdi). our results show that ehpdi behaves mainly as an oxidase/isomerase and can be inhibited by bacitracin, a known pdi inhibitor; moreover, it exhibits chaperone-like activity. albeit its physiological role i ...201121320491
[failure to offer parasitology screening to vulnerable migrants in france: epidemiology and consequences.]the "consultations de diagnostic et d'orientation" (cdo), created in 1998 by the paris health department, are medical consultations for vulnerable populations, which are held in municipal clinics, free of charge. more than two-thirds of cdo patients come from africa. our study was designed to assess and analyze whether these clinics offered consulting migrants screening for intestinal parasitic and schistosoma haematobium infections.material and methodsthis retrospective study included all immig ...201021320812
infectious diarrhea: cellular and molecular mechanisms.diarrhea caused by enteric infections is a major factor in morbidity and mortality worldwide. an estimated 2-4 billion episodes of infectious diarrhea occur each year and are especially prevalent in infants. this review highlights the cellular and molecular mechanisms underlying diarrhea associated with the three classes of infectious agents, i.e., bacteria, viruses and parasites. several bacterial pathogens have been chosen as model organisms, including vibrio cholerae as a classical example of ...201021327112
a sequential model of host cell killing and phagocytosis by entamoeba histolytica.the protozoan parasite entamoeba histolytica is responsible for invasive intestinal and extraintestinal amebiasis. the virulence of entamoeba histolytica is strongly correlated with the parasite's capacity to effectively kill and phagocytose host cells. the process by which host cells are killed and phagocytosed follows a sequential model of adherence, cell killing, initiation of phagocytosis, and engulfment. this paper presents recent advances in the cytolytic and phagocytic processes of entamo ...201121331284
in vivo programmed cell death of entamoeba histolytica trophozoites in a hamster model of amoebic liver abscess.entamoeba histolytica trophozoites can induce host cell apoptosis, which correlates with the virulence of the parasite. this phenomenon has been seen during the resolution of an inflammatory response and the survival of the parasites. other studies have shown that e. histolytica trophozoites undergo programmed cell death (pcd) in vitro, but how this process occurs within the mammalian host cell remains unclear. here, we studied the pcd of e. histolytica trophozoites as part of an in vivo event r ...201121349978
influence of inflammation on parasitism and area of experimental amoebic liver abscess: an immunohistochemical and morphometric study.the influence of inflammation on the number of trophozoites and on the murine amoebic liver abscess area following infection with entamoeba histolytica and e. dispar was evaluated. immunohistochemistry and digital morphometry were used to identify and quantify the trophozoites, neutrophils, macrophages, and lesions. positive correlation was observed between the number of trophozoites and inflammatory cells. a significant decrease in parasitism and inflammation in groups treated with dexamethason ...201121356065
antiprotozoal activity of chloroquinoline based chalcones.a new series of chloroquinoline based chalcones were synthesized and evaluated for in vitro antiamoebic and antimalarial activities. the results showed that out of fifteen compounds, four were found to be more active against the entamoeba histolytica; while one compound was moderatively active compared to the standard drug metronidazole (ic50=1.46 µm). in contrast, in vitro antimalarial activity against the chloroquine-sensitive (3d7) strain of p. falciparum indicated relatively low activity whe ...201121377771
an optimum diagnostic test for amoebic liver abscess in endemic areas: are we there yet? 201021381570
resistance to tetracyclines, macrolides, trimethoprim and sulfonamides.tetracyclines are antimicrobial agents that interact with bacterial ribosomes and block protein synthesis. they have activity against a wide range of gram positive, gram-negative, anaerobic and aerobic bacteria, cell-wall free myco plasmas, chlamydiae, mycobacteria, rickettsia, helicobacter, listeria, and protozoan parasites, such as entamoeba histolytica, gzardia lamblia, and plas modiumfalciparum 1-6. tetracyclnes have been extenstvely used in humans for therapy of bacterial respiratory and ur ...199821390769
a mutation in the leptin receptor is associated with entamoeba histolytica infection in children.malnutrition substantially increases susceptibility to entamoeba histolytica in children. leptin is a hormone produced by adipocytes that inhibits food intake, influences the immune system, and is suppressed in malnourished children. therefore we hypothesized that diminished leptin function may increase susceptibility to e. histolytica infection. we prospectively observed a cohort of children, beginning at preschool age, for infection by the parasite e. histolytica every other day over 9 years a ...201121393862
synthesis of benzologues of nitazoxanide and tizoxanide: a comparative study of their in vitro broad-spectrum antiprotozoal activity.we have synthesized two new benzologues of nitazoxanide (nit) and tizoxanide (tiz), using a short synthetic route. both compounds were tested in vitro against six protozoa (giardia intestinalis, trichomonas vaginalis, entamoeba histolytica, plasmodium berghei, leishmania mexicana and trypanosoma cruzi). compound 1 (benzologue of nit) showed broad antiprotozoal effect against all parasites tested, showing ic(50)'s<5 ++m. this compound was five-times more active than nit, and 18-times more potent ...201121397502
protective effects of mlif analogs on cerebral ischemia-reperfusion injury in rats.the monocyte locomotion inhibitory factor (mlif) is an anti-inflammatory oligopeptide produced by entamoeba histolytica. among its different effects, it inhibits locomotion of human monocytes, hence its original name. the carboxyl-terminal end group cys-asn-ser is the pharmacophore of anti-inflammatory peptide met-gln-cys-asn-ser. in this study, the n-terminal of cys-asn-ser was modified. with the aim to enhance the antioxidant ability and penetrability of cys-asn-ser, we designed and synthesize ...201121402115
a c2 domain protein kinase initiates phagocytosis in the protozoan parasite entamoeba histolytica.phagocytosis is a process whereby particles are taken in by cells through mechanisms superficially similar to those for endocytosis. it serves a wide range of functions, from providing nutrition in unicellular organisms to initiation of both innate and adaptive immunity in vertebrates. in the protozoan parasite entamoeba histolytica, it has an essential role in survival and pathogenesis. in this study, we show that ehc2pk, a c2-domain-containing protein kinase, and the ca²(+) and actin-binding p ...201121407196
entamoeba histolytica/entamoeba dispar infection in chronic hemodialysis patients.to determine the prevalence of entamoeba histolytica/e. dispar (eh/ed) in chronic hemodialysis (hd) patients, we collected 330 samples of feces from 110 patients, and nine individuals were found to be positive for eh/ed. we compared the infected patients with a group of 14 uninfected hd patients. both groups were analyzed for their signs, symptoms and socio-economic characteristics using questionnaires. blood tests were also performed in both the groups. although both groups did not differ stati ...201121422620
current and future perspectives on the chemotherapy of the parasitic protozoa trichomonas vaginalis and entamoeba histolytica.trichomonas vaginalis and entamoeba histolytica are clinically important protozoa that affect humans. t. vaginalis produces sexually transmitted infections and e. histolytica is the causative agent of amebic dysentery. metronidazole, a compound first used to treat t. vaginalis in 1959, is still the main drug used worldwide to treat these pathogens. it is essential to find new biochemical differences in these organisms that could be exploited to develop new antiprotozoal chemotherapeutics. recent ...200921426030
calpain mediates degradation of cytoskeletal proteins during jurkat t-cell death induced by entamoeba histolytica.entamoeba histolytica is known to induce host cell death via activation of calpain and caspases. in this study, we investigated the specific proteases involved in the degradation of cytoskeletal proteins during jurkat t-cell death induced by e. histolytica. amoebic trophozoites induced marked degradation of paxillin, cas, vimentin, vinculin and talin, as well as a- or ß-spectrin, in jurkat t cells. the cleavage effects of e. histolytica were strongly retarded by pretreatment with a calpain inhib ...201121426360
evaluation of antidiarrheal and in vitro antiprotozoal activities of extracts of leaves of alocasia indica.alocasia indica schott (araceae) is used in several regions of india, especially in rural communities, by traditional medicine practitioners to treat diarrhea. however, no scientific data are available to justify the traditional potentials of the plant species in gastrointestinal disorders.201121428863
the cysteine protease inhibitors ehicp1 and ehicp2 perform different tasks in the regulation of endogenous protease activity in trophozoites of entamoeba histolytica.trophozoites of e. histolytica are equipped with two chagasin-like cysteine protease inhibitors, ehicp1 and ehicp2, also known as amoebiasin 1 and 2. expression studies using e. invadens as model organism showed that corresponding mrnas were detectable in both life stages of the parasite, cyst and trophozoite state. unlike ehicp1 known to act in the cytosol, ehicp2 co-localized with cysteine protease ehcp-a1 in lysosome-like vesicles, as demonstrated by immunofluorescence microscopy. silencing o ...201121440496
tissue destruction and invasion by entamoeba histolytica.entamoeba histolytica is the causative agent of amebiasis, a disease that is a major source of morbidity and mortality in the developing world. the potent cytotoxic activity of the parasite appears to underlie disease pathogenesis, although the mechanism is unknown. recently, progress has been made in determining that the parasite activates apoptosis in target cells and some putative effectors have been identified. recent studies have also begun to unravel the host genetic determinants that infl ...201121440507
identification of a polypeptide containing tudor and staphyloccocal nuclease-like domains as the sequence-specific binding protein to the upstream regulatory element 1 of entamoeba histolytica.transcription initiation is the most regulated stage for the control of gene expression. this event requires that a complex of proteins called transcription factors bind to dna through cis-regulatory elements located in the gene promoters. however, little is known about transcription regulation in entamoeba histolytica, the protozoan parasite responsible for human amoebiasis. some genes encoding for proteins involved in the parasite pathogenicity contain specific upstream regulatory elements (ur ...201121447339
virulence of entamoeba histolytica: a challenge for human health research. 201121449836
[non-pathogenic intestinal amoebae: a clinical-analytical overview].human beings can be parasitized by various species of intestinal amoebae. entamoeba histolytica is the only intestinal amoeba recognized to be pathogenic, while other amoeba species, e. dispar, e. moshkovskii, e. hartmanni, e. coli, e. polecki, endolimax nana and iodamoeba buetschlii are considered to be non-pathogenic. the aim of this review is to synthesize the main morphological characteristics of the trophozoite and cyst stages of each amoeba as the basis for precise microscopical diagnosis. ...201121458707
[intestinal parasitosis prevalence in outpatients and inpatients of cã granda irccs foundation - ospedale maggiore policlinico of milan: data comparison between 1984-1985 and 2007-2009].this paper evaluates the prevalence of intestinal parasitosis in a specific population over three years (2007-2009). the results were compared with published data collected from the same population in 1984-1985. during a survey from january 1st 2007 to december 31(st) 2009 a total of 2962 inpatients and outpatients were evaluated in our facility (irccs foundation - ospedale maggiore policlinico) for ova and protozoa stool examination (ope) over three specimens collected alternatively for three d ...201121471744
in vitro amoebicidal activity of borage (borago officinalis) extract on entamoeba histolytica.abstract borage (borago officinalis) is a plant with nutritional value that is also used in traditional medicine to treat gastrointestinal disease. this study investigated the amoebicidal activity of a methanol extract of borage. the 50% inhibitory concentration (ic(50)) of the extract for entamoeba histolytica was 33 μg/ml. the 50% lethal dose of the extract for brine shrimp was greater than 1,000 μg/ml. the ic(50) of the extract for vero cells was 203.9 μg/ml. these results support the use of ...201121476887
kinetic characterization and gene expression of adenosine deaminase in intact trophozoites of trichomonas vaginalis.trichomonas vaginalis is a parasite that resides in the human urogenital tract and causes trichomonosis, the most prevalent nonviral sexually transmitted disease. nucleoside triphosphate diphosphohydrolase (ntpdase), which hydrolyzes extracellular di- and triphosphate nucleotides, and ecto-5'-nucleotidase, which hydrolyzes amp, have been characterized in t. vaginalis. the aim of this study was to characterize the adenosine deaminase (ada) activity in intact trophozoites of t. vaginalis. a strong ...201121477257
amoebic dysentery.amoebic dysentery is caused by the protozoan parasite entamoeba histolytica. it is transmitted in areas where poor sanitation allows contamination of drinking water and food with faeces. in these areas, up to 40% of people with diarrhoea may have amoebic dysentery. methods and outcomes: we conducted a systematic review and aimed to answer the following clinical question: what are the effects of drug treatments for amoebic dysentery in endemic areas? we searched: medline, embase, the cochrane lib ...201121477391
prevalence of intestinal parasitic infections among hiv patients in benin city, nigeria.this study was carried out to determine the presence of intestinal parasites and their correlation with cd4(+) t-cell counts and demographics among human immunodeficiency virus (hiv)-positive patients in benin city, nigeria. stool specimens from 2,000 hiv-positive patients and 500 controls (hiv-negative individuals) were examined for ova, cysts, or parasites, using standard procedures. in addition, patient's blood samples were analyzed for cd4 counts by flow cytometry. an overall prevalence rate ...201021483561
a proteomic and cellular analysis of uropods in the pathogen entamoeba histolytica.exposure of entamoeba histolytica to specific ligands induces cell polarization via the activation of signalling pathways and cytoskeletal elements. the process leads to formation of a protruding pseudopod at the front of the cell and a retracting uropod at the rear. in the present study, we show that the uropod forms during the exposure of trophozoites to serum isolated from humans suffering of amoebiasis. to investigate uropod assembly, we used lc-ms/ms technology to identify protein component ...201121483708
high prevalence of entamoeba infections in captive long-tailed macaques in china.long-tailed macaques (macaca fascicularis) are bred in china for export and for use in experiments. entamoeba infections in captive long-tailed macaques were surveyed in one of the biggest colonies located in guangxi province, china. one stool sample was obtained from each of the 152 different cages representing >3,000 macaques in the colony. the samples were examined by pcr for five entamoeba species. the number of detected entamoeba coli infections comprised 94% of the samples, 93% for entamoe ...201121484347
a novel ex vivo set-up for dynamic long-term characterization of processes on mucosal interfaces by confocal imaging and simultaneous cytokine measurements.we present a novel organ-explant imaging system for easy and cost-effective extended-time observation of host-pathogen interactions at mucosal interfaces. data are complemented by parallel cytokine measurements at high temporal resolution. the set-up is based on a custom-built reusable organ chamber compatible with standard microscopes. luminal and basal side of the explanted mucosa are connected to separate channels for optimized incubation and cytokine measurements, oxygen is provided via memb ...201121496196
melatonin reduces the severity of experimental amoebiasis.abstract:201121501501
validation and utilization of pcr for differential diagnosis and prevalence determination of entamoeba histolytica/entamoeba dispar in salvador city, brazil.amoebiasis is an infection caused by entamoeba histolytica and is a potential health risk in countries in which health barriers are inappropriate. since the discovery of entamoeba dispar, the prevalence of amoebiasis has been modified.201121503397
dna methylation in drosophila--a critical evaluation.drosophila belongs to the so-called "dnmt2 only" organisms, and does not contain any of the canonical dna methyltransferases (dnmt1 and dnmt3). furthermore, no functional homologs of known 5-methylcytosine reader proteins are found. nevertheless, there is strong evidence for dna methylation in this organism. it has been suggested that dna methylation in drosophila is simply a byproduct of dnmt2, which is a dna methyltransferase (dnmt) according to structure and type of catalysis but functions in ...201121507351
involvement of thermoplasmaquinone-7 in transplasma membrane electron transport of entamoeba histolytica trophozoites: a key molecule for future rational chemotherapeutic drug designing.the quinone composition of the transplasma membrane electron transport chain of parasitic protozoa entamoeba histolytica was investigated. purification of quinone from the plasma membrane of e. histolytica and its subsequent structural elucidation revealed the structure of the quinone as a methylmenaquinone-7 (thermoplasmaquinone-7), a napthoquinone. membrane bound thermoplasmaquinone-7 can be destroyed by uv irradiation with a concomitant loss of plasma membrane electron transport activity. the ...201121523408
comparison of the flotac-400 dual technique and the formalin-ether concentration technique for diagnosis of human intestinal protozoon infection.there is a need for accurate diagnosis of intestinal parasite infections in humans, but currently available copromicroscopic techniques have shortcomings, such as low sensitivity. we compared the diagnostic accuracy of a further modified version of the recently developed flotac technique with that of the widely used formalin-ether concentration technique (fect) for the detection of intestinal protozoa in human stool samples. formaldehyde-preserved stool samples from 108 individuals in côte d'ivo ...201121525226
health problems of peacekeepers carrying out mandatory tasks in chad, central africa.background. the article presents the results of the author's own studies concerning the morbidity profile in the group of soldiers serving in the polish military contingent (pmc) deployed to chad in the period may 2008-april 2009 within the framework of a european union operation (eufor) and a united nations peacekeeping mission (minurcat). material and methods. the conducted analysis was based on medical records of soldiers (n = 540) treated at level 1 (fob iriba) and level 2 (hq abeche) medica ...201121534224
the expression of reg 1a and reg 1b is increased during acute amebic colitis.entamoeba histolytica, a protozoan parasite, is an important cause of diarrhea and colitis in the developing world. amebic colitis is characterized by ulceration of the intestinal mucosa. we performed microarray analysis of intestinal biopsies during acute and convalescent amebiasis in order to identify genes potentially involved in tissue injury or repair. colonic biopsy samples were obtained from 8 patients during acute e. histolytica colitis and again 60days after recovery. gene expression in ...201121586335
success of medical therapy in a rare case of cecal ameboma. 201121592907
[perianal cutaneous amebiasis. report of two cases.] 201121592908
genome-wide analysis of mobile genetic element insertion sites.mobile genetic elements (mges) account for a significant fraction of eukaryotic genomes and are implicated in altered gene expression and disease. we present an efficient computational protocol for mge insertion site analysis. elan, the suite of tools described here uses standard techniques to identify different mges and their distribution on the genome. one component, dnascanner analyses known insertion sites of mges for the presence of signals that are based on a combination of local physical ...201121609951
differential distribution of a sine element in the entamoeba histolytica and entamoeba dispar genomes: role of the line-encoded endonuclease.abstract: background: entamoeba histolytica and entamoeba dispar are closely related protistan parasites but while e. histolytica can be invasive, e. dispar is completely non pathogenic. transposable elements constitute a significant portion of the genome in these species; there being three families of lines and sines. these elements can profoundly influence the expression of neighboring genes. thus their genomic location can have important phenotypic consequences. a genome-wide comparison of th ...201121612594
the investigation of entamoeba histolytica prevalence in some villages of sivas by elisa method.objective: humans may be infected with three morphologically identical entamoeba species; pathogenic e. histolytica, commensal e. moshkowskii and e. dispar. the aim of the present study was to determine the true prevalence of the e. histolytica using native lugol, trichrome staining and a monoclonal antigen detection kit (elisa kit e. histolytica-ii; techlab, inc., blacksburg, va) among primary school children living in the rural areas around sivas. methods: a total of 1449 stool samples were ex ...201121618183
[frequency of intestinal parasites among administrators and workers in sanitary and non-sanitary institutions.]objective: transmission of parasites generally occurs through fecal-oral means directly from human to human or through receiving eggs and cysts by means of nourishment. the aim of the study was to investigate the frequency of intestinal parasites among administrators and workers in sanitary and non-sanitary institutions. methods: stool specimens were examined using native-lugol, trichrome and acid-fast stains methods. results: 23.7% of the 2443 fecal specimens were found to be positive. the freq ...201121618189
differentiation of entamoeba histolytica: a possible role for enolase.the study of the encystation process of entamoeba histolytica has been hampered by the lack of experimental means of inducing mature cysts in vitro. previously we have found that cytoplasmic vesicles similar to the encystation vesicles of entamoeba invadens are present in e. histolytica trophozoites only in amebas recovered from experimental amebic liver abscesses. here we report that a monoclonal antibody (b4f2) that recognizes the cyst wall of e. invadens also identifies a 48kda protein in ves ...201121619880
human liver sinusoidal endothelial cells respond to interaction with entamoeba histolytica by changes in morphology, integrin signalling and cell death.invasive infection with entamoeba histolytica causes intestinal and hepatic amoebiasis. in liver, parasites cross the endothelial barrier before abscess formation in the parenchyma. we focussed on amoebae interactions with human hepatic endothelial cells, the latter potentially playing a dual role in the infection process: as a barrier and as modulators of host defence responses. we characterized early responses of a human liver sinusoidal endothelial cell line to virulent and virulence-attenuat ...201121624031
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