| an unusual surface peroxiredoxin protects invasive entamoeba histolytica from oxidant attack. | peroxiredoxins are an important class of antioxidant enzymes found from archaea to humans, which reduce and thereby detoxify peroxides and peroxynitrites. the major thiol-containing surface antigen of the invasive ameba, entamoeba histolytica, is a peroxiredoxin and is likely to be important during the transition from the anaerobic environment of the large intestine to human tissues. the closely related species, entamoeba dispar, is incapable of invasion and more sensitive to hydrogen peroxide, ... | 2005 | 15996766 |
| detection of serum antibody to entameba histolytica in various population samples of amebic infection using an enzyme-linked immunosorbent assay. | microscopic identification of entameba histolytica in stool is insensitive to differentiate this pathogenic ameba from morphologically identical entameba dispar. an enzyme-linked immunosorbent assay method was applied for diagnosing amebiasis by detection of e. histolytica antibody. a total of 258 sample sera were analyzed from five different groups including amebiasis patients, e. histolytica/e. dispar asymptomatic cyst carriers, patients clinically presumed to have intestinal and extra-intesti ... | 2005 | 15997409 |
| altered lipid parameters in patients infected with entamoeba histolytica, entamoeba dispar and giardia lamblia. | information on the effect of parasitic infections on lipid parameters is scarce. certain parasites induce significant changes in lipid parameters, as demonstrated by the fact that substitution of lipid/cholesterol for serum in axenic culture medium (in vitro) and in experimental models (in vivo) supports vigorous growth of entamoeba histolytica. thus, significant changes in lipid parameters may be induced in an infected host. blood samples are obtained from intestinal amoebiasis patients passing ... | 2005 | 15997878 |
| synthesis and antiamoebic activity of new oxime ether derivatives containing 2-acetylpyridine/2-acetylfuran. | various oxime ether derivatives of 2-acetylpyridine and 2-acetylfuran series have been synthesised. o-alkylation of the oximes by various alkylaminoethyl halides gave the corresponding oxime ether derivatives. the structures of these compounds were elucidated by uv, ir, 1h nmr, 13c nmr spectroscopic methods and elemental analyses. all the compounds were screened in vitro against the hm1:imss strain of entamoeba histolytica. based on the 50% inhibitory concentration (ic50) data of the 12 compound ... | 2005 | 16002285 |
| high prevalence rate of entamoeba histolytica asymptomatic infection in a rural mexican community. | the frequency of entamoeba histolytica and entamoeba dispar infection was analyzed in a rural community in the state of morelos, mexico, using polymerase chain reaction (pcr). sociodemographic variables as risk factors for the infection were assessed. results highlighted the number of individuals with intestinal parasites (43.1%) in the community, indicating extensive fecalism. a high frequency of e. histolytica asymptomatic infection, higher than e. dispar infection (13.8% versus 9.6%), was det ... | 2005 | 16014840 |
| cellular and molecular mechanisms that underlie entamoeba histolytica pathogenesis: prospects for intervention. | the protozoan parasite entamoeba histolytica is the causative agent of amoebic dysentery. it is prevalent in developing countries that cannot prevent its fecal-oral spread and ranks second in worldwide causes of morbidity by parasitic infection. improvements in sanitation would help curb disease spread. however, a lack of significant progress in this area has resulted in the need for a better understanding of the molecular and cellular biology of pathogenesis in order to design novel methods of ... | 2005 | 16026630 |
| golgi and endoplasmic reticulum functions take place in different subcellular compartments of entamoeba histolytica. | entamoeba histolytica is a protozoan parasite that causes dysentery in developing countries of africa, asia, and latin america. the lack of a defined golgi apparatus in e. histolytica as well as in other protists led to the hypothesis that they had evolved prior to the acquisition of such organelle even though glycoproteins, glycolipids, and antigens have been detected, the latter of which react with antibodies against golgi apparatus proteins of higher eukaryotes. we here provide direct evidenc ... | 2005 | 16027148 |
| roles for the galactose-/n-acetylgalactosamine-binding lectin of entamoeba in parasite virulence and differentiation. | entamoeba histolytica, an intestinal protozoan parasite, is a major cause of morbidity and mortality in developing countries. the pathology of the disease is caused by the colonization of the large intestine by the amoebic trophozoites and the invasion of the intestinal epithelium. some of the trophozoites will eventually differentiate into the infectious cyst form, allowing them to be transmitted out of the bowel and into water supplies to be passed from person to person. both the virulence of ... | 2005 | 16037494 |
| [utility and limitations of laboratory diagnosis of amebiasis]. | entamoeba histolytica is an invasive and pathogenic protozoan parasite that causes amebiasis. it must be distinguished from entamoeba dispar, a nonpathogenic commensal parasite of the human gut lumen that is morphologically identical to entamoeba histolytica. diagnosis of amoebic colitis currently requires combination of microscopic examination of stool specimens with another technique allowing positive identification of the two species. stool culture followed by zymodem analysis is considered a ... | 2005 | 16038358 |
| resistance to intestinal entamoeba histolytica infection is conferred by innate immunity and gr-1+ cells. | establishment of intestinal infection with entamoeba histolytica depends on the mouse strain; c57bl/6 mice are highly resistant, and c3h/hej mice are relatively susceptible. we found that resistance to intestinal infection was independent of lymphocyte activity or h-2 haplotype and occurred in the first hours to days postchallenge according to in vivo imaging. at 18 h postchallenge, the ceca of resistant c57bl/6 mice were histologically unremarkable, in contrast to the severe inflammation observ ... | 2005 | 16040963 |
| [diarrhea in stress. 56-year iv retiree]. | | 2005 | 16078753 |
| prevalence of parasitism among students of the karen hill-tribe in mae chame district, chiang mai province, thailand. | infection caused by intestinal parasites is still a common health problem in a poor-hygiene population especially for children in developing countries. a cross-sectional study was conducted among 781 karen students (age: 3 to 19, males: 325, females: 456) to determine the current status of intestinal parasitic infections in a mountainous area in the north of thailand. the study was drawn from three schools in the doi inthanon region, in mae chame district of chiang mai province, from december 20 ... | 2004 | 16083202 |
| monoadp-ribosylation of the nad+-dependent alcohol dehydrogenase from entamoeba histolytica. | the human parasite entamoeba histolytica is an amitochondrial protozoan whose metabolism depends on glucose fermentation. among the metabolic enzymes absolutely required for amoeba growth is the nad+-dependent alcohol dehydrogenase (ehadh2). the polymeric form of ehadh2 was sedimented at 160,000 g, and in this fraction we observed [32p]-labeling of a 96-kda protein under mono-adp-ribosylation conditions with [32p]nad+. the [32p]-labeled protein had the same molecular weight as the ehadh2 monomer ... | 2005 | 16086106 |
| structure prediction of a multi-domain ef-hand ca2+ binding protein by propainor. | propainor is a new algorithm developed for ab initio prediction of the 3d structures of proteins using knowledge-based nonparametric multivariate statistical methods. this algorithm is found to be most efficient in terms of computational simplicity and prediction accuracy for single-domain proteins as compared to other ab initio methods. in this paper, we have used the algorithm for the atomic structure prediction of a multi-domain (two-domain) calcium-binding protein, whose solution structure h ... | 2005 | 16094534 |
| the entamoeba histolytica genome: something old, something new, something borrowed and sex too? | the recent publication of the protozoan parasite entamoeba histolytica genome provides new insights into eukaryotic evolution, the role of lateral gene transfer in amebic biology and the adaptations required for eukaryotes that reside within the human intestine. | 2005 | 16098811 |
| identification of a very large rab gtpase family in the parasitic protozoan trichomonas vaginalis. | rab proteins are pivotal components of the membrane trafficking machinery in all eukaryotes. distinct rab proteins locate to specific endomembrane compartments and genomic studies suggest that rab gene diversity correlates with endomembrane system complexity; for example unicellular organisms generally possess 5-20 rab family members and the size of the repertoire increases to 25-60 in multicellular systems. here we report 65 open reading frames from the unicellular protozoan trichomonas vaginal ... | 2005 | 16099517 |
| entamoeba: still more to be learned from the genome. | | 2005 | 16099723 |
| infection by human immunodeficiency virus-1 is not a risk factor for amebiasis. | the purpose of this study was to determine whether hiv-1 infected patients in our community were more susceptible to entamoeba histolytica and entamoeba dispar infection than non-hiv-infected individuals. the prevalence and frequency of invasive amebiasis was determined in 203 hiv+/aids subjects and 140 close relatives or sexual partners, all of whom were hiv-. anti-e. histolytica antibodies (igg, iga) were assessed as indicators of e. histolytica invasive infection. polymerase chain reaction (p ... | 2005 | 16103593 |
| differences in morphology of phagosomes and kinetics of acidification and degradation in phagosomes between the pathogenic entamoeba histolytica and the non-pathogenic entamoeba dispar. | phagocytosis plays an important role in the pathogenicity of the intestinal protozoan parasite entamoeba histolytica. we compared the morphology of phagosomes and the kinetics of phagosome maturation using conventional light and electron microscopy and live imaging with video microscopy between the virulent e. histolytica and the closely-related, but non-virulent e. dispar species. electron micrographs showed that axenically cultivated trophozoites of the two entamoeba species revealed morpholog ... | 2005 | 16106449 |
| biologic insights from the sequenced genome of entamoeba histolytica. | | 2005 | 16107225 |
| [diagnostic tests: entamoeba histolytica]. | | 2005 | 16111248 |
| structural characterization of the apo form of a calcium binding protein from entamoeba histolytica by hydrogen exchange and its folding to the holo state. | one of the calcium binding proteins from entamoeba histolytica (ehcabp) is a 134 amino acid residue long (m(r) approximately 14.9 kda) double domain ef-hand protein containing four ca(2+) binding sites. cd and nmr studies reveal that the ca(2+)-free form (apo-ehcabp) exists in a partially collapsed form compared to the ca(2+)-bound (holo) form, which has an ordered structure (pdb id ). deuterium exchange studies on the partially structured apo-ehcabp reveal that the c-terminal domain is better s ... | 2005 | 16114901 |
| a retromerlike complex is a novel rab7 effector that is involved in the transport of the virulence factor cysteine protease in the enteric protozoan parasite entamoeba histolytica. | vesicular trafficking plays an important role in a virulence mechanism of the enteric protozoan parasite entamoeba histolytica as secreted and lysosomal cysteine protease (cp) contributes to both cytolysis of tissues and degradation of internalized host cells. despite the primary importance of intracellular sorting in pathogenesis, the molecular mechanism of cp trafficking remains largely unknown. in this report we demonstrate that transport of cp is regulated through a specific interaction of r ... | 2005 | 16120649 |
| comparative genomics of dictyostelium discoideum and entamoeba histolytica. | amoebozoa represent one of the earliest branches from the last common ancestor of all eukaryotes and contain some of the most dangerous human pathogens. two amoebozoan genomes -- from the model organism dictyostelium discoideum and the human pathogen entamoeba histolytica -- have been published this year. owing to their high a+t content, both genomes were difficult to sequence. in addition to nine amoebozoan expressed sequence tag projects, efforts are underway for comparative sequencing of four ... | 2005 | 16125444 |
| pcr differentiation of entamoeba histolytica and entamoeba dispar from patients with amoeba infection initially diagnosed by microscopy. | amoebiasis is a notifiable disease in sweden and 400-500 cases are reported annually to the swedish institute for infectious disease control (smi). the true number of patients with entamoeba histolytica infection is unknown as diagnosis mainly relies on cyst detection by microscopy. the main purpose of this study was to estimate the proportions between e. histolytica and e. dispar in patients with amoebic infection, using established pcr technologies. secondly, we aimed to evaluate the usefulnes ... | 2005 | 16126570 |
| copper(ii) complexes with substituted thiosemicarbazones of thiophene-2-carboxaldehyde: synthesis, characterization and antiamoebic activity against e. histolytica. | in an effort to develop potent antiamoebic agents, a series of thiosemicarbazone (tsc) ligands 1-5 derived from thiophene-2-carboxaldehyde and n4-substituted thiosemicarbazides has been prepared and characterized using various spectroscopic techniques. treatment of the ligands with cupric chloride produced the copper(ii) complexes [cu(tsc)2cl2] 1a-5a where ligand bind through thionic sulfur and the azomethine nitrogen. the possible geometries of the complexes were assigned on the basis of magnet ... | 2005 | 16129515 |
| use of rapid dipstick and latex agglutination tests and enzyme-linked immunosorbent assay for serodiagnosis of amebic liver abscess, amebic colitis, and entamoeba histolytica cyst passage. | a homemade enzyme-linked immunosorbent assay (elisa) and a dipstick assay (dipstick) for the detection of anti-entamoeba histolytica antibodies in serum were developed and evaluated together with a commercially available latex agglutination test (lat; laboratoires fumouze) for their use in serodiagnosis of amebiasis. the sensitivity of these assays was evaluated with sera from 27 patients with radiologically proven, cellulose acetate precipitation (cap) test-positive amebic liver abscess, 7 pati ... | 2005 | 16145144 |
| coding and noncoding genomic regions of entamoeba histolytica have significantly different rates of sequence polymorphisms: implications for epidemiological studies. | to evaluate genetic variability among entamoeba histolytica strains, we sequenced 9,077 bp from each of 14 isolates. the polymorphism rates from coding and noncoding regions were significantly different (0.07% and 0.37%, respectively), indicating that these regions are subject to different selection pressures. additionally, single nucleotide polymorphisms (snps) potentially associated with specific clinical outcomes were identified. | 2005 | 16145147 |
| preparation of entamoeba histolytica antigens without enzymatic inhibitors. | the goal of this work is to report a novel assay that preserves antigenicity of extracts with high protease content without using enzymatic inhibitors. a great reduction of proteolytic activity in the insoluble chloroform/methanol and heated amoebic fraction (ic:mc) was obtained by this method, even in the presence of sodium dodecyl sulphate and 2-mercaptoethanol. the substrates azo-casein and the hide powder azure were used to determine the reduction of proteolytic activity of ic:mc compared wi ... | 2005 | 16145939 |
| characterization of chaperonin 10 (cpn10) from the intestinal human pathogen entamoeba histolytica. | entamoeba histolytica is the causative agent of amoebiasis, a poverty-related disease that kills an estimated 100 000 people each year. e. histolytica does not contain "standard mitochondria", but harbours mitochondrial remnant organelles called mitosomes. these organelles are characterized by the presence of mitochondrial chaperonin cpn60, but little else is known about the functions and molecular composition of mitosomes. in this study, a gene encoding molecular chaperonin cpn10--the functiona ... | 2005 | 16151221 |
| signalization and cytoskeleton activity through myosin ib during the early steps of phagocytosis in entamoeba histolytica: a proteomic approach. | phagocytosis of human cells is a crucial activity for the virulence of the human parasite entamoeba histolytica. this protozoan invades and destroys the intestine by killing and phagocytosing epithelial cells, erythrocytes and cells from the immune system. in this study, we used magnetic beads covered with proteins from human serum as a model system to study the early events involved in phagocytosis by e. histolytica. we validated the system showing that the beads uptake triggered the activation ... | 2005 | 16153248 |
| protozoan parasite-specific carbohydrate structures. | the carbohydrate moieties displayed by pathogenic protozoan parasites exhibit many unusual structural features and their expression is often developmentally regulated. these unique structures suggest a specific relationship between such carbohydrates and parasite pathogenicity. studies of infected humans indicate that immune responses to protozoan parasites are elicited by glycan determinants on cell-surface or secreted molecules. infections by protozoa are a major worldwide health problem, and ... | 2005 | 16154349 |
| the effect of electromagnetic waves on the growth of entamoeba histolytica and entamoeba dispar. | the aim of this study was to investigate the influence of electromagnetic radiation of a digital global system for mobile communication mobile telephone (900 mhz) on entamoeba histolytica (e. histolytica) and entamoeba dispar (e. dispar) (cysts or trophozoites, or both) in a 24-hour period. | 2005 | 16155653 |
| gene discovery in the acanthamoeba castellanii genome. | acanthamoeba castellanii is a free-living amoeba found in soil, freshwater, and marine environments and an important predator of bacteria. acanthamoeba castellanii is also an opportunistic pathogen of clinical interest, responsible for several distinct diseases in humans. in order to provide a genomic platform for the study of this ubiquitous and important protist, we generated a sequence survey of approximately 0.5 x coverage of the genome. the data predict that a. castellanii exhibits a greate ... | 2005 | 16171187 |
| additional antiprotozoal constituents from cuphea pinetorum, a plant used in mayan traditional medicine to treat diarrhoea. | in addition to kaempferol and quercetin already found in the roots from cuphea pinetorum, bioassay-guided fractionation of the crude extract of the aerial part of this species gave four flavonoid glycosides, quercetin-3-o-alpha-rhamnopyranoside, luteolin-7-o-beta-d-glucopyranoside, apigenin-7-o-alpha-l-rhamnopyranoside and apigenin-7-o-beta-d-glucopyranoside, as well as squalen and beta-sitosterol. in vitro antiamoebic and antigiardial activities of isolated compounds indicated that kaempferol i ... | 2005 | 16177979 |
| sweet's syndrome--an extraintestinal manifestation in inflammatory bowel disease. | sweet's syndrome (ss) is a severe dermatosis that may be an extraintestinal manifestation of inflammatory bowel disease (ibd). worldwide, 35 cases of ss associated with ibd have been reported. we present the first case of severe, recurrent ss in combination with amebic infection and ulcerative colitis complicated with multiple other extraintestinal manifestations. | 2005 | 16179788 |
| a rare cause of acute appendicitis: parasitic infection. | the role of parasitic infection in the aetiology of acute appendicitis has been discussed for more than 100 years. the aim of this retrospective study was to determine the prevalence of parasitic infection in surgically removed appendices, and to identify whether this type of infection is associated with appendicitis. 104 appendices were removed from patients clinically diagnosed with acute appendicitis, and 30 were removed in the course of other surgical procedures. all the operations were perf ... | 2005 | 16191896 |
| identification of a family of bspa like surface proteins of entamoeba histolytica with novel leucine rich repeats. | | 2006 | 16199101 |
| [intestinal parasitic diseases in hiv-infected patients in uzbekistan]. | intestinal parasitic diseases were diagnosed in 100 hiv-infected patients at different stages of disease (its asymptomatic form, persistent generalized lymphoadenopathy, pre-aids, and aids) (group 1), 100 tashkent residents (group 2), and 349 patients with gastrointestinal diseases, allergic dermatoses, and skin depigmentation foci (group 3). the hiv-infected patients were found to have virtually all parasites, such as giardia lamblia, cryptosporidium parvum, chilomastix mesnili, entamoeba coli, ... | 2005 | 16212098 |
| [prevalence of infection by intestinal parasites in north lebanon: 1997-2001]. | we determined the prevalence of intestinal parasites in the north of lebanon between 1997 and 2001. we analysed the parasitology records of 17126 patients and evidence of parasitic infections was found in 5 713 (33.35%) cases. there was no significant difference in prevalence for males or females for any of the parasites. the most prevalent parasites were entamoeba coli (38.45%), ascaris lumbricoides (37.14%), giardia lamblia (15.39%), ent. histolytica (4.57%) and taenia sp. (3.3%). a comparison ... | 2004 | 16212211 |
| synthesis, spectral studies and in vitro assessment for antiamoebic activity of new cyclooctadiene ruthenium(ii) complexes with 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones. | we report here the synthesis, characterization and in vitro antiamoebic activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones (tsc), 1-5, and their bidentate complexes [ru(eta(4)-c(8)h(12))(tsc)cl(2)] 1a-5a. the biological studies of these compounds were investigated against hk-9 strain of entamoeba histolytica and the concentration causing 50% cell growth inhibition (ic(50)) was calculated in the micromolar range. the ligands exhibited antiamoebic activity in the range (2.05-5.29micr ... | 2005 | 16213728 |
| [amoebic infections of the lung and pleura]. | pleuropulmonary involvement is the second most common extra-intestinal manifestation of entamoeba histolytica infection after liver abscess. | 2005 | 16217543 |
| characterization of entamoeba histolytica alpha-actinin. | we have cloned, expressed and characterized a alpha-actinin-like protein of entamoeba histolytica. analysis of the primary structure reveals that the essential domains of the alpha-actinin protein family are conserved: an n-terminus actin-binding domain, a c-terminus calcium-binding domain and a central helical rod domain. however, the rod domain of this entamoeba protein is considerably shorter than the rod domain in alpha-actinins of higher organisms. the cloned entamoeba 63 kda protein is rec ... | 2006 | 16219372 |
| amebiasis in infancy in the middle-high socioeconomic class in istanbul, turkey. | amebiasis is a major cause of morbidity and mortality worldwide. we present 11 children with acute entamoeba histolytica infection. none of the infants developed extraintestinal disease or required hospitalization. light microscopy results correlated with stool antigen test for e. histolytica. breast-feeding and middle-high socioeconomic status does not protect infants from infection with e. histolytica in endemic areas. | 2005 | 16220097 |
| vaccine prospects for amebiasis. | entamoeba histolytica is a eukaryotic protozoan parasite and is the causative agent of amebic colitis and amebic liver abscess. many insights into the innate and acquired immune responses to infection with e. histolytica have been made in recent years. these findings have provided a foundation for producing a vaccine that could help to prevent the initial establishment of infection in the intestinal wall. the galactose and n-acetyl-d-galactosamine-specific lectin on the surface of the ameba is a ... | 2005 | 16221067 |
| hemolytic uremic syndrome associated with entamoeba histolytica intestinal infection. | amebiasis secondary to entamoeba histolytica (e. histolytica) continues to be a major source of morbidity and mortality worldwide, mainly in developing countries. an association between amebic dysentery and hemolytic uremic syndrome (hus) has been mentioned, but a cause-and-effect relationship has never been confirmed. we report the case of an 11-year-old healthy white female who developed severe bloody diarrhea after drinking contaminated unboiled water, developing classic hus and requiring acu ... | 2006 | 16222550 |
| amoebic renal cyst: a case report. | entamoeba histolytica can infect any organ of the body, but only one case of renal involvement has been reported till now in the literature. we report a rare case of amoebic renal cyst in a 78-year showing favorable outcome with metronidazole treatment and therapeutic drainage. | 2005 | 16224635 |
| sulfur-containing amino acid metabolism in parasitic protozoa. | sulfur-containing amino acids play indispensable roles in a wide variety of biological activities including protein synthesis, methylation, and biosynthesis of polyamines and glutathione. biosynthesis and catabolism of these amino acids need to be carefully regulated to achieve the requirement of the above-mentioned activities and also to eliminate toxicity attributable to the amino acids. genome-wide analyses of enzymes involved in the metabolic pathways of sulfur-containing amino acids, includ ... | 2005 | 16230102 |
| cytokine and chemokine responses in patients co-infected with entamoeba histolytica/dispar, necator americanus and mansonella perstans and changes after anti-parasite treatment. | this study examined the impact of concurrent parasite infections (amoebiasis, filariasis, necatoriasis) and the effect of anti-parasite treatment on cytokine and chemokine responses in singly and poly-parasitized patients. cellular reactivity and parasite-specific th1- and th2-type cytokine and chemokine profiles were investigated before and six weeks after treatment. in those patients infected with three parasite species, cellular secretion of interleukin 5 (il-5) and il-12p40 by pbmc was stron ... | 2006 | 16239120 |
| glycosylated inositol phospholipid from entamoeba histolytica: identification and structural characterization. | | 2006 | 16242191 |
| sensitivity and specificity of a new commercial enzyme-linked immunoassay kit for detecting entamoeba histolytica igg antibodies in serum samples. | the study presented here was conducted to evaluate the performance of the newly available ridascreen set (r-biopharm ag, darmstadt, germany) for the detection of immunoglobulin g antibodies against entamoeba histolytica. the sensitivity and specificity of this new enzyme-linked immunosorbent assay were evaluated using a panel of sera from 239 individuals. the assay was positive for 43 of 44 patients with invasive amebiasis, including all 18 patients with amebic liver abscess, while it was negati ... | 2005 | 16261304 |
| entamoeba moshkovskii and entamoeba dispar-associated infections in pondicherry, india. | the prevalence of laredo strain--entamoeba moshkovskii--and non-pathogenic e. dispar in patients attending the jawaharlal institute of postgraduate medical education and research hospital, pondicherry, india, is reported here. e. moshkovskii is reported for the first time in india. the species are morphologically indistinguishable from pathogenic e. histolytica. of 746 stool samples screened, 68 showing cyst or trophozoite stage of e. histolytica, e. dispar, or e. moshkovskii were subjected to s ... | 2005 | 16262027 |
| epigenetic and classical activation of entamoeba histolytica heat shock protein 100 (ehsp100) expression. | the protozoan parasite entamoeba histolytica expresses a cytosine-5 dna methyltransferase (ehmeth) that belongs to the dnmt2 protein family. the biological function of members of this dnmt2 family is unknown. in the present study, the 5' region of e. histolytica heat shock protein 100 (5'ehsp100) was isolated by affinity chromatography with 5-methylcytosine antibodies as ligand. the methylation status of 5'ehsp100 was confirmed by sodium bisulfite sequencing. we showed that the expression of ehs ... | 2005 | 16263115 |
| comparison of real-time pcr protocols for differential laboratory diagnosis of amebiasis. | specific identification of entamoeba spp. in clinical specimens is an important confirmatory diagnostic step in the management of patients who may be infected with entamoeba histolytica, the species that causes clinical amebiasis. distinct real-time pcr protocols have recently been published for identification of e. histolytica and differentiation from the morphologically identical nonpathogenic entamoeba dispar. in this study, we compared three e. histolytica real-time pcr techniques published ... | 2005 | 16272475 |
| the abp-120 c-end region from entamoeba histolytica interacts with sulfatide, a new lipid target. | ehabp-120 is the first filamin identified in the parasitic protozoan entamoeba histolytica. filamins are a family of cross-linking actin-binding proteins that promote a dynamic orthogonal web. they have been reported to interact directly with more than 30 cellular proteins and some phosphoinositides. the biochemical consequences of these interactions may have either positive or negative effects on the cross-linking function and also form a link between the cytoskeleton and plasma membrane. in th ... | 2005 | 16274663 |
| entamoeba histolytica and entamoeba dispar: comparison of two pcr assays for diagnosis in a non-endemic setting. | detection of entamoeba histolytica, the causative agent of amoebiasis, is an important goal of the clinical parasitology laboratory. the identification of entamoeba dispar as a morphologically identical but non-pathogenic species has highlighted the need for non-microscopic detection methods able to differentiate between the two organisms. in this study we evaluated the utility of conventional pcr and real-time pcr as methods for identification and differentiation of e. histolytica and e. dispar ... | 2006 | 16274714 |
| involvement of a short interspersed element in epigenetic transcriptional silencing of the amoebapore gene in entamoeba histolytica. | transcriptional silencing of an amoebapore (ap-a) gene occurred in entamoeba histolytica following the transfection of plasmids containing a dna segment (473 bp) homologous to the 5' upstream region of the gene (r. bracha, y. nuchamowitz, and d. mirelman, eukaryot. cell 2:295-305, 2003). this segment contains the promoter region of the ap-a gene, a t-rich stretch, followed by a truncated sine1 (short interspersed element 1) that is transcribed from the antisense strand. transfection of plasmids ... | 2005 | 16278444 |
| amebic colitis in asymptomatic subjects with positive fecal occult blood test results: clinical features different from symptomatic cases. | amebiasis is a common parasitic infectious disease in developing countries. in developed countries, it is occasionally encountered in travelers to the tropics and in homosexual males. during the past eight years, we detected four cases of amebic colitis among 5,193 subjects who underwent colonoscopy because of positive fecal occult blood test results in a mass screening. all four cases did not have any abdominal symptoms. ulcerative lesions were observed only in the cecum and ascending colon; an ... | 2005 | 16282306 |
| entamoeba histolytica sequences and their relationship with experimental liver abscesses in hamsters. | the purpose of the present paper was to analyse the association between sequences of entamoeba histolytica and their relationship with the development of hepatic abscesses in hamsters, using a complementary dna library for e. histolytica. from the sequences obtained, we designed oligonucleotides for amplification by pcr. trophozoites were isolated from faeces of 11 patients in whom cysts from e. histolytica were identified, and these trophozoites were then subjected to monoaxenic culture. then 1 ... | 2006 | 16283410 |
| prevalence and genetic diversity of entamoeba histolytica in an institution for the mentally retarded in the philippines. | a total of 113 mentally retarded patients residing in a mental institution in metropolitan manila, philippines, were screened for the presence of entamoeba histolytica based on microscopy and polymerase chain reaction (pcr). anti-e. histolytica antibodies were also screened in 97 serum samples collected using immunofluorescence antibody (ifa) test. parasitological examination showed e. histolytica/entamoeba dispar in 43 cases (38.05%), while pcr detected 74 cases (65.48%) positive for e. histoly ... | 2006 | 16284779 |
| biochemical and functional characterization of phosphoserine aminotransferase from entamoeba histolytica, which possesses both phosphorylated and non-phosphorylated serine metabolic pathways. | the enteric protozoan parasite entamoeba histolytica is a unicellular eukaryote that possesses both phosphorylated and non-phosphorylated serine metabolic pathways. in the present study, we described enzymological and functional characterization of phosphoserine aminotransferase (psat) from e. histolytica. e. histolytica psat (ehpsat) showed maximum activity for the forward reaction at basic ph, dissimilar to mammalian psat, which showed sharp neutral optimum ph. ehpsat activity was significantl ... | 2006 | 16289358 |
| kinetics and strain variation of phagosome proteins of entamoeba histolytica by proteomic analysis. | the protozoan parasite entamoeba histolytica ingests and feeds on microorganisms and mammalian cells. phagocytosis is essential for cell growth and implicated in pathogenesis of e. histolytica. we report here the dynamic changes of phagosome proteins during phagosome maturation by proteomic analysis using reversed-phase capillary liquid chromatography and ion trap tandem mass spectrometry. phagosomes were isolated at various intervals after internalization of latex beads. immunoblot analysis and ... | 2006 | 16290089 |
| dehydroepiandrosterone decreases while cortisol increases in vitro growth and viability of entamoeba histolytica. | in vitro exposure of entamoeba histolytica trophozoites to the sex steroids 17beta-estradiol, progesterone, and dehydrotestosterone had little effect on parasite viability or proliferation. however, treatment with the adrenal steroid dehydroepiandrosterone (dhea) markedly inhibited parasite proliferation, adherence and motility, and at a certain dose it induced trophozoite lysis. the opposite effect on proliferation was found when the trophozoites were exposed to cortisol. moreover, dhea decreas ... | 2006 | 16293437 |
| comparative evaluation of hexokinase isoenzyme typing and antigen detection for differentiation of entamoeba histolytica and entamoeba dispar. | entamoeba histolytica, the causative organism of invasive amebiasis is a potential pathogen, while asymptomatic infection is caused by e. dispar. differentiation of the species is not possible on the basis of morphological characters by microscopic examination. in the present study an attempt has been made to differentiate e. histolytica from e. dispar in 45 isolates obtained from culture and direct stool samples respectively on the basis of hexokinase isoenzyme analysis and tech lab elisa. a 10 ... | 2004 | 16295743 |
| reduction of cell surface glycosylphosphatidylinositol conjugates in entamoeba histolytica by antisense blocking of e. histolytica glcnac-phosphatidylinositol deacetylase expression: effect on cell proliferation, endocytosis, and adhesion to target cells. | glycosylphosphatidylinositol (gpi)-anchored molecules such as cell surface gal/galnac lectin and proteophosphoglycans of the protozoan parasite entamoeba histolytica are thought to be involved in pathogenesis. here, we report the identification of genes that may be involved in the gpi biosynthetic pathway of e. histolytica by use of bioinformatic tools applied to the recently published genome sequence. of the genes identified, one of the early genes, glcnac-phosphatidylinositol deacetylase (pig- ... | 2005 | 16299336 |
| characterization of protein geranylgeranyltransferase i from the enteric protist entamoeba histolytica. | entamoeba histolytica is a unique protozoan parasite possessing both protein farnesyltransferase and geranylgeranyltrasferase i (ggt-i) for isoprenylation of small gtpases. in this study, we demonstrated unique enzymological properties of the amebic ggt-i (ehggt-i), including substrate specificity and insensitivity to known mammalian inhibitors. some of important residues of the catalytic beta subunit implicated in the specificity for gtpase acceptors and prenyl donors are substituted in ehggt-i ... | 2006 | 16300841 |
| synthesis and antiamoebic activity of new 1-n-substituted thiocarbamoyl-3,5-diphenyl-2-pyrazoline derivatives and their pd(ii) complexes. | some 1-n-substituted thiocarbamoyl-3,5-diphenyl-2-pyrazoline derivatives (l), 1-8 were synthesized by a base-catalyzed claisen-schmidt condensation of benzaldehyde with acetophenone followed by cyclization with various n-4 substituted thiosemicarbazides. the palladium(ii) complexes [pdlcl2], 1a-8a of these ligands were obtained by reacting them with [pd(dmso)2cl2]. all compounds have been characterized by means of elemental analyses, electronic, ir, 1h nmr and mass spectroscopic data, while the ... | 2006 | 16300860 |
| unique organisation of trna genes in entamoeba histolytica. | the genome sequence of the protistan parasite entamoeba histolytica hm-1:imss has been completed recently. among the findings has been a unique organisation for the trna genes in this organism. forty-two of the trna isoacceptor types are encoded in tandem arrays that vary in unit length from 490 to 1775 basepairs and contain from 1 to 5 trna genes. in three cases a 5s rna gene is also present in the unit. an estimated 10% of the genome is made up of these arrays. interspersed between rna-encodin ... | 2006 | 16307803 |
| etiology of childhood diarrhea in zliten, libya. | to determine the etiological agents of diarrhea in children from a small semi-urban city in libya and the association of age, gender, seasonal variation, breast-feeding, source of water for drinking, or antibiotic use with the isolation of enteropathogens and whether such agents are community or hospital acquired. | 2005 | 16311662 |
| use of pcr amplification of trna gene-linked short tandem repeats for genotyping entamoeba histolytica. | we have developed a reliable method for pcr-based genotyping of entamoeba histolytica based on variation in the numbers of short tandem repeats that are linked to trna genes in this species. species-specific primer pairs were designed that differentiate e. histolytica from e. dispar as well as that reveal intraspecies pcr product length polymorphisms. the primers were tested with samples from different parts of the world, and dna was extracted from cultured cells as well as liver abscess pus and ... | 2005 | 16333065 |
| microscopic overdiagnosis of intestinal amoebiasis. | to determine the misdiagnosis of intestinal amoebiasis associated to microscopic examination of faeces, 50 stool samples of patients infected with entamoeba histolytica were collected from different primary health care centers, hospitals and private laboratories in ismailia g. the samples were examined using wheatley's trichrome staining technique to differrentiate e. histolytica e. dispar complex from other non-pathogenic intestinal amoebae and multiplex polymerase chain reaction (pcr). pcr dif ... | 2005 | 16333901 |
| geoparasites in rural dakahlia governorate, a preliminary based study for development of the community-based intervention programs. | a prospective study was carried out to detect the rural prevalence and intensity of geoparasites in dakahlia governorate, egypt. a total of 1070 soil samples were collected; 571 (53.4%) were infected with one or more parasites. only 24% of samples were infected with one parasite, 16.4% and 13% with two, and more than two parasites respectively, and the difference was statistically significant. the geoparasites in a descending order of their prevalence were: e. histolytica cysts (9.2%), toxocara ... | 2005 | 16333910 |
| enhanced pro-inflammatory chemokine/cytokine response triggered by pathogenic entamoeba histolytica : basis of invasive disease. | the virulence of entamoeba histolytica is governed by adhesion/colonization in the gut which is mediated by a galactose specific lectin. two morphologically identical but distinct species i.e. pathogenic e. histolytica and non-pathogenic e. dispar, can be differentiated by distinct epitopes in the lectin. both species bind to colonic epithelial cells, but only e. histolytica infection induces an inflammatory response and subsequent pathogenesis. thus, comparing the responses of the intestinal ce ... | 2005 | 16336732 |
| human hololactoferrin: endocytosis and use as an iron source by the parasite entamoeba histolytica. | entamoeba histolytica is an enteric protozoan that exclusively infects human beings. this parasite requires iron for its metabolic functions. lactoferrin is a mammalian glycoprotein that chelates extracellular iron on mucosal surfaces, including the surface of the large intestine, where e. histolytica initiates infection. this work examined the interaction in vitro of e. histolytica trophozoites with human hololactoferrin (iron-saturated lactoferrin). a minimum concentration of 50 microm fe from ... | 2005 | 16339932 |
| could the homologous sequence of anti-inflammatory pentapeptide (mlif) produced by entamoeba histolytica in the n protein of rabies virus affect the inflammatory process? | amebiasis and rabies are public health problems, and they have in common a poor inflammatory effect in the target organs that they affect. in the genbank, it was found that the anti-inflammatory peptide monocyte locomotion inhibitory factor (mlif) produced by entamoeba histolytica homologates 80%, with a fragment of the n protein of the rabies virus. we speculated if the n protein could contribute to the scant inflammatory reaction produced by rabies virus in central nervous system. the n protei ... | 2006 | 16341883 |
| membrane-permeabilizing polypeptides of amoebae - constituents of an archaic antimicrobial system. | amoebae may be viewed as primitive, actively phagocytosing eukaryotic cells, many of which use bacteria as a major nutrient source. at a very archaic level, amoebae exert mechanisms which kill bacteria comparable to those found in phagocytic cells of higher organisms. accordingly, it is tempting to suggest that the ancestors of effector cells of the innate immune system were bacteria-feeding amoebae and that their molecular armament is ancient. here, we summarize the characteristics of antimicro ... | 2001 | 16351813 |
| comparing the dictyostelium and entamoeba genomes reveals an ancient split in the conosa lineage. | the amoebozoa are a sister clade to the fungi and the animals, but are poorly sampled for completely sequenced genomes. the social amoeba dictyostelium discoideum and amitochondriate pathogen entamoeba histolytica are the first amoebozoa with genomes completely sequenced. both organisms are classified under the conosa subphylum. to identify amoebozoa-specific genomic elements, we compared these two genomes to each other and to other eukaryotic genomes. an expanded phylogenetic tree built from th ... | 2005 | 16362072 |
| the utility of lactoferrin in differentiating parasitic from bacterial infections. | lactoferrin is an iron binding glycoprotein found in the 2ry granules of pmn. in order to determine the usefulness of such marker for neutrophilic activity in differentiating cases suffering from amoebic and bacillary dysentery, schistosoma and bacterial uti infections, we examined stool and urine specimens using anti-lactoferrin antibodies (lactoferrin latex agglutination test: lfla), compared with different standard gold techniques. our results demonstrated that cases with either shigllosis or ... | 2005 | 16363291 |
| human fascioliasis among immigrant workers in saudi arabia. | animal fascioliasis has been reported in saudi arabia among imported and local sheep. the paper demonstrated the parasitological and clinical features of human fascioliasis in nine out of ten male immigrant manual workers with manifestations suggesting fascioliasis. the sedimentation and kato-katz techniques proved effect in diagnosing fasciola species eggs in human stool. the common clinical features were abdominal distension, flatulence, tender right-upper quadrant and easy fatigability and th ... | 2005 | 16363294 |
| entamoeba histolytica up-regulates the cdc48-like protein, an aaa family member, during the activation of trophozoites with collagen type i and calcium. | | 2006 | 16364463 |
| sexual dimorphism in the control of amebic liver abscess in a mouse model of disease. | amebic liver abscess (ala) is the most common extraintestinal manifestation of human infection by the enteric protozoan parasite entamoeba histolytica. in contrast to intestinal infection, ala greatly predominates in males but is rare in females. since humans are the only relevant host for e. histolytica, experimental studies concerning this sexual dimorphism have been hampered by the lack of a suitable animal model. by serial liver passage of cultured e. histolytica trophozoites in gerbils and ... | 2006 | 16368964 |
| identification of differentially expressed genes in virulent and nonvirulent entamoeba species: potential implications for amebic pathogenesis. | entamoeba histolytica is a protozoan parasite that causes colitis and liver abscesses. several entamoeba species and strains with differing levels of virulence have been identified. e. histolytica hm-1:imss is a virulent strain, e. histolytica rahman is a nonvirulent strain, and entamoeba dispar is a nonvirulent species. we used an e. histolytica dna microarray consisting of 2,110 genes to assess the transcriptional differences between these species/strains with the goal of identifying genes who ... | 2006 | 16368989 |
| cpg-oligodeoxynucleotide is a potent adjuvant with an entamoeba histolytica gal-inhibitable lectin vaccine against amoebic liver abscess in gerbils. | the protozoan parasite entamoeba histolytica causes invasive amoebiasis characterized by amoebic dysentery and liver abscesses (ala). the e. histolytica galactose/n-acetyl-d-galactosamine-inhibitable lectin (gal-lectin), an immunogenic surface molecule involved in colonization and invasion, is a promising vaccine candidate against amoebiasis. gal-lectin is known to induce th1 cytokines in macrophages and spleen cells in vitro, and a th1 response is thought to be protective against ala. in this s ... | 2006 | 16369009 |
| cytokine expression in cd4(+) cells exposed to the monocyte locomotion inhibitory factor produced by entamoeba histolytica. | entamoeba histolytica produces monocyte locomotion inhibitory factor (mlif), a pentapeptide with in vitro and in vivo anti-inflammatory properties. mlif may interfere with leukocyte migration, disturbing the balance of pro- and anti-inflammatory cytokines secreted by cd4(+) t lymphocytes. we evaluated the effect of mlif on expression of pro- and anti-inflammatory cytokines in human cd4(+) t lymphocytes. regulatory cytokines [interleukin-1 beta (il-1beta), il-2, interferon gamma (ifn-gamma), il-5 ... | 2006 | 16374615 |
| membrane trafficking as a virulence mechanism of the enteric protozoan parasite entamoeba histolytica. | | 2006 | 16374616 |
| pathogenesis of acute experimental liver amebiasis. | classical descriptions of the pathology of amebiasis portray the parasite as the cause of tissue damage and destruction, and in recent years a number of amebic molecules have been identified as virulence factors. in this review we describe a series of experiments that suggest a more complex host-parasite relation, at least during the early stages of acute experimental amebic liver abscess in hamsters. the problems of extrapolating experiments in vitro to explain observations in vivo are discusse ... | 2006 | 16380320 |
| experimental amebiasis: a selected review of some in vivo models. | the use of in vivo animal models in amebiasis has contributed significantly to the knowledge of this common human parasitic disease. although there is no animal model that mimics the whole cycle of the human disease, the use of different susceptible and resistant laboratory animals and the availability for many years of techniques for the axenic culture of trophozoites of entamoeba histolytica have allowed a better understanding of the parasite and the host-parasite relationship. the recent intr ... | 2006 | 16380321 |
| calcium-binding proteins of entamoeba histolytica. | calcium plays an essential role in many fundamental processes in almost all eukaryotic cells including protozoan parasite entamoeba histolytica. many of the calcium-mediated processes are carried out through the help of calcium-binding proteins (cabps). a few of these e. histolytica cabps have been described before. these proteins are unique to this organism and are thought to be essential. availability of genome sequence has opened up the possibility of studying cabps at the whole genome level. ... | 2006 | 16380322 |
| epigenetic silencing of gene expression in entamoeba histolytica. | transcriptional silencing of an amebapore (ap-a) gene occurred in entamoeba histolytica following the transfection of plasmids containing a dna segment (473 bp) homologous to the 5' upstream region of the gene. this segment contains the promoter region of the ap-a gene, a t-rich stretch, followed by a truncated sine1 (short interspersed element) that is transcribed from the opposite strand. the downstream silencing of the ap-a gene did not occur with plasmids containing the entire sine1 sequence ... | 2006 | 16380323 |
| the cytoskeleton of entamoeba histolytica: structure, function, and regulation by signaling pathways. | pathogenesis in the parasite entamoeba histolytica has been related to motility of the trophozoites. motility is an important feature in amebas as they perform multiple motile functions during invasion of host tissues. as motility depends on the organization and regulation of the cytoskeleton elements, in particular of the actin cytoskeleton, the study of the molecular components of the machinery responsible for movement has been a key aspect to study in this parasite. although many of the compo ... | 2006 | 16380324 |
| new insights into molecular mechanisms of phagocytosis in entamoeba histolytica by proteomic analysis. | the protozoan parasite entamoeba histolytica ingests microorganisms and mammalian cells. phagocytosis is essential for cell growth and is implicated in pathogenesis of e. histolytica. phagocytosis consists of a number of steps including recognition of and binding to ligands on the target cells via a galactose/n-acetylgalactosamine-specific lectin, activation of a signaling pathway leading to cytoskeletal reorganization, and vesicle trafficking, all of which play distinct but coordinated roles in ... | 2006 | 16380325 |
| host tissue invasion by entamoeba histolytica is powered by motility and phagocytosis. | during amebiasis, e. histolytica motility is a key factor to achieve its progression across tissues. the pathogenicity of e. histolytica includes its capacity to phagocyte human cells. motility requires polarization of e. histolytica that involves protrusion of a pseudopod containing actin and associated proteins [myosin ib, abp-120 and a p21-activated kinase (pak)] and whole-cell propulsion after contraction of the rear of the cell, where myosin ii and f-actin are concentrated. an interesting c ... | 2006 | 16380326 |
| methods for the investigation of diversity in entamoeba histolytica. | the ability to distinguish variants of a species has many potential applications. in entamoeba histolytica the first method to detect variation was based on isoenzyme analysis. however, this approach has been superseded by dna-based analysis. in this review i discuss the basis of the variation detected in e. histolytica by the various molecular methods that have been published to date. information on diversity in other species is mentioned where such information exists. | 2006 | 16380327 |
| prevalence and incidence of entamoeba histolytica infection in south africa and egypt. | there are little data on the true prevalence and incidence of entamoeba histolytica infection in africa. this is due to the inability, historically, to differentiate entamoeba histolytica from the more common, but non-pathogenic, entamoeba dispar. in addition, newer studies have demonstrated that the previous gold standard, culture with zymodeme analysis, is insensitive in detecting the presence of infection, especially when compared to pcr. recent published articles as well as data from the aut ... | 2006 | 16380329 |
| epidemiology and treatment of amebiasis in hué, vietnam. | hué, a city of about 300,000 inhabitants in central vietnam, is known as a "hot spot" for diseases caused by entamoeba histolytica and in particular for amebic liver abscess (ala), thus representing an excellent site for studies on the epidemiology and treatment of e. histolytica infections. accordingly, during the last few years, various studies on this topic have been performed in hué in close collaboration among the hué medical college, the hué central hospital and the bernhard nocht institut ... | 2006 | 16380330 |
| diversity of clinical isolates of entamoeba histolytica in japan. | in japan, amebiasis is domestically transmitted by two major populations: male homosexuals and mentally handicapped persons, which is remarkably different from most other developed countries where entamoeba dispar infection is predominantly observed. here we briefly summarize epidemiology of amebiasis in japan. we also review our current understanding of the diversity of entamoeba histolytica clinical isolates in japan, based on polymorphic genetic markers, clinical representations, and in vivo ... | 2006 | 16380332 |
| adherence-blocking vaccine for amebiasis. | the gal/galnac lectin is a candidate vaccine antigen for an amebiasis vaccine due to its mediation of parasite adherence to the human intestine, because partial immunity in humans is associated with a mucosal iga response against it, and because it is effective as a vaccine against amebic colitis in the murine model. the leca domain of the gal/galnac lectin contains neutralizing antibody epitopes. leca contains the active site of the lectin (the carbohydrate recognition domain or "crd") and has ... | 2006 | 16380334 |
| the current status of an amebiasis vaccine. | efficient control of infectious diseases requires the development and application of suitable vaccines. development of vaccines against amebiasis is still in its infancy. however, in recent years progress has been made in the identification of possible vaccine candidates, the route of application and the understanding of the immune response that is required for protection against amebiasis. | 2006 | 16380335 |
| genomic and proteomic approaches highlight phagocytosis of living and apoptotic human cells by the parasite entamoeba histolytica. | phagocytosis plays a major role during the invasive process of the human intestine by the pathogenic amoeba e. histolytica. this parasite is the etiologic agent causing amoebic dysentery, a worldwide disease causing 50 million of clinical cases leading to about 100,000 deaths annually. the invasive process is characterized by a local acute inflammation and the destruction of the intestinal tissue at the invasion site. the recent sequencing of the e. histolytica genome has opened the way to large ... | 2006 | 16386742 |
| entamoeba histolytica: fyve-finger domains, phosphatidylinositol 3-phosphate biosensors, associate with phagosomes but not fluid filled endosomes. | endocytosis is an important virulence function for entamoeba histolytica, the causative agent of amoebic dysentery. although a number of e. histolytica proteins that regulate this process have been identified, less is known about the role of lipids. in other systems, phosphatidylinositol 3-phosphate (pi3p), a product of phosphatidylinositol 3-kinase (pi 3-kinase), has been shown to be required for endocytosis. fyve-finger domains are protein motifs that bind specifically to pi3p. using a pi3p bi ... | 2006 | 16387299 |