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the entamoeba histolytica mitochondrion-derived organelle (crypton) contains double-stranded dna and appears to be bound by a double membrane.amebae have an hsp60-associated, mitochondrion-derived organelle (crypton). in this study, the crypton was stained with multiple dna-binding fluorochromes and a monoclonal anti-double-stranded dna antibody. transmission microscopy of partially purified cryptons revealed organelles bound by a double membrane.200010858251
pcr detection of giardia lamblia in stool: targeting intergenic spacer region of multicopy rrna gene.a pcr based detection that amplifies the 552-bp intergenic spacer (igs) region of multicopy rrna gene of giardia lamblia and 320-bp internal sequences to first pcr product has been used in diagnosis of giardiasis in stool sample. the primers were found highly specific to giardia spp. only, because no amplification was observed with dnas from other enteric pathogens like escherichia coli, shigella dysenteriae and entamoeba histolytica. the test could detect even less than 2 pg of genomic dna from ...200010860716
effect of dinitroaniline herbicides on the growth of entamoeba histolytica.the effect of the dinitroaniline herbicides oryzalin and trifluralin on the growth of entamoeba histolytica was examined. oryzalin inhibited the growth of e. histolytica strain hm-1:imss. trifluralin was less effective than oryzalin for this parasite. entamoeba histolytica was more resistant to these dinitroanilines than other parasitic protozoa examined so far, including leishmania spp., trypanosoma brucei, plasmodium falciparum, toxoplasma gondii, and cryptosporidium parvum. colchicine, a pote ...200010864261
evaluation of indirect fluorescent antibody test and enzyme-linked immunosorbent assay for diagnosis of hepatic amebiasis in bangladesh.serum samples of 31 amebic liver abscess (ala) patients, 8 amebic hepatitis (ah) patients, and 60 controls were tested for anti-amebic igg by enzyme-linked immunosorbent assay (elisa) and indirect fluorescent antibody tests (ifat). sera of 29 (93.6%) ala and 6 (75%) ah patients and 2 (3.3%) control subjects were positive by ifat. anti-amebic antibody titer above the cutoff point (= 0.168; x + 2 sd of control sera) was observed in sera of 27 (87%) ala, 4 (50%) ah, and 1 (1.7%) control by elisa. a ...200010864262
inhibition and stimulation of growth of entamoeba histolytica in culture: association with pkc activity and protein phosphorylation.we studied the role of protein kinase c (pkc) and protein threonine phosphorylation in the inhibition and stimulation of growth of the protozoan parasite entamoeba histolytica. pkc was activated after serum deprivation in e. histolytica and during this period proteins became threonine phosphorylated. conversely, on serum stimulation of serum-deprived cells, pkc activation was rapidly reversed and the threonine phosphorylation of proteins quickly declined. growth of e. histolytica was not affecte ...200010864515
bacterial, viral and parasitic enteric pathogens associated with acute diarrhea in hospitalized children from northern jordan.to determine the etiology of acute diarrhea in jordanian children under 5 years of age, we examined stool samples from 265 children admitted to the pediatric ward at princess rahma hospital for children, irbid, jordan, for parasites, rotavirus and enteric bacteria. using both traditional and molecular diagnostic techniques, we detected enteropathogens in 66.4% of patients with diarrhea. a single enteric pathogen was detected in 50.9% of the children, and multiple pathogens were detected in 15.5% ...200010865179
[amebiasis].amoebiasis caused by the enteric protozoan entamoeba histolytica is a widespread parasitic disease, which causes 40,000 to 100,000 deaths per year. cases diagnosed in denmark are always imported. infection results from ingestion of amoebic cysts, which after excystation form trophozoits in the small intestine, colonize the bowel lumen and invade the intestinal epithelium resulting in amoebic colitis. spread to the liver and formation of amoebic liver abscesses occurs in one third of the cases, w ...200010868107
osteomyelitis of the ribs in the antibiotic era.a total of 106 cases of rib osteomyelitis were reviewed, including 2 cases described in detail. mycobacterial and bacterial infections accounted for 47 cases each. fungal rib osteomyelitis occurred in 11 cases and 1 case was caused by entamoeba histolytica. most cases occurred in children and young adults. the mean duration of symptoms before diagnosis was 16, 26 and 32 weeks for bacterial, mycobacterial and fungal rib osteomyelitis, respectively. common clinical signs were fever (73%), soft tis ...200010879590
entamoeba histolytica/entamoeba dispar infections in human immunodeficiency virus-infected patients in the united states.we describe the incidence of and laboratory and clinical characteristics associated with entamoeba histolytica/entamoeba dispar infection diagnosed in human immunodeficiency virus (hiv)-infected persons enrolled in the adult and adolescent spectrum of hiv disease project. from 1 january 1990 to 1 january 1998 (82, 518 person-years of follow-up), 111 patients (98% men) were diagnosed with e. histolytica/e. dispar infection. among hiv-infected patients in the united states, the incidence of diagno ...200010880314
response: entamoeba infections in human immunodeficiency virus-infected patients: not just a tropical problem. 200010880315
mg, mn, and co ions enhance the formation of entamoeba histolytica cyst-like structures resistant to sodium dodecyl sulfate.entamoeba histolytica forms cyst-like structures (cls) in pehps but not in tys-33 medium. sodium dodecyl sulfate [(sds (0.1%)] dissolves most of them in 10 min, but not natural cysts. chitin is responsible mainly for cyst wall resistance. its synthesis depends on mg(2)+, mn(2)+, or co(2)+, whose action is interactive. with the aid of the simplex method, we analyzed the effect of 20 blends of these cations to find the one that, when added to pehps, produced the highest proportion of cls resistant ...200010880721
cell polarization and adhesion in a motile pathogenic protozoan: role and fate of the entamoeba histolytica gal/galnac lectin.the human pathogenic protozoan entamoeba histolytica is a motile cell polarized into a front pseudopod and a rear uroid. the amoebic gal/galnac surface lectin is a major adhesion molecule composed of an immunodominant 170-kda heavy subunit, mostly extracellular except for a short cytoplasmic tail, and of an extracellular light subunit. the binding of multivalent ligands triggers lectin capping and recruitment to the uroid. the properties of the gal/galnac lectin and its role in amoeba adhesion a ...200010884615
a nested, multiplex, pcr assay for the simultaneous detection and differentiation of entamoeba histolytica and entamoeba dispar in faeces.the detection of and differentiation between entamoeba histolytica and entamoeba dispar are of great importance, both for diagnosis and for epidemiological studies. most pcr-based methods for the discrimination of these two species employ complex procedures for dna extraction and require different protocols for e. histolytica and e. dispar, leading to relatively high expenditure, labour costs and turnaround times. a simple, rapid, cost-effective and yet sensitive and specific multiplex pcr techn ...200010884867
epidemiology of infections with intestinal parasites and human immunodeficiency virus (hiv) among sugar-estate residents in ethiopia.intestinal parasitic infections could play an important role in the progression of infection with human immunodeficiency virus (hiv), by further disturbing the immune system whilst it is already engaged in the fight against hiv. hiv and intestinal parasitic infections were investigated in 1239, randomly selected individuals, aged 15-54 years, living on a sugar estate in central ethiopia. intestinal parasites were identified in faecal samples (one/subject) using direct, concentration, and (for st ...200010884872
food-borne protozoa.pathogenic protozoa are commonly transmitted to food in developing countries, but food-borne outbreaks of infection are relatively rare in developed countries. the main protozoa of concern in developed countries are toxoplasma, cryptosporidium and giardia, and these can be a problem in immunocompromised people. other protozoa such as entamoeba histolytica, cyclospora cayetanensis and sarcocystis can be a food-borne problem in non-industrialised countries. c. cayetanensis has emerged as a food-bo ...200010885117
absence of lipophosphoglycan-like glycoconjugates in entamoeba dispar.invasive amoebiasis is the result of infection of entamoeba histolytica. the closely related entamoeba dispar can colonize the human gut but does not cause invasive disease. in this study, e. dispar was analysed for the presence of the lipophosphoglycan-like (lpg) glycoconjugate known to be present on the cell surface of e. histolytica. e. dispar cells were radio-isotope labelled with [3h]galactose or [3h]inositol. the acidic glycoconjugates were extracted and analysed by hydrophobic chromatogra ...200010726263
galactose-specific adhesin and cytotoxicity of entamoeba histolytica.we examined the molecular mechanisms of the cytotoxicity of entamoeba histolytica, using the loss of transepithelial electrical resistance (ter) of monolayers of madin-darby canine-kidney (mdck) cells on their incubation with axenic trophozoites of the hm1-imss strain. such loss of ter occurs very early (in 2-5 min) and is caused by the opening of tight junctions and the detachment of cells. we used specific inhibitors for three of the four molecules currently accepted as being responsible for c ...200010726993
superoxide dismutase reduces susceptibility to metronidazole of the pathogenic protozoan entamoeba histolytica under microaerophilic but not under anaerobic conditions. 200010729211
asymptomatic cyst passers of entamoeba histolytica but not entamoeba dispar in institutions for the mentally retarded in japan.entamoeba histolytica/entamoeba dispar was isolated from 50 asymptomatic amebic cyst passers in three institutions for the mentally retarded in kanagawa prefecture, japan. to distinguish between e. histolytica and e. dispar, the isolates were analyzed by pcr, reactivity to monoclonal antibodies, and zymodemes. all isolates were identified as e. histolytica. the results lead us to conceive that, in japan, e. histolytica is predominant even in asymptomatic cyst passers.200010729715
the genome of entamoeba histolytica.estimation of genome size of entamoeba histolytica by different methods has failed to give comparable values due to the inherent complexities of the organism, such as the uncertain level of ploidy, presence of multinucleated cells and a poorly demarcated cell division cycle. the genome of e. histolytica has a low g+c content (22.4%), and is composed of both linear chromosomes and a number of circular plasmid-like molecules. the rrna genes are located exclusively on some of the circular dnas. kar ...200010731563
neo-inositol polyphosphates in the amoeba entamoeba histolytica.we have reexamined the structure of inositol phosphates present in trophozoites of the parasitic amoeba entamoeba histolytica and show here that, rather than being myo-inositol derivatives (martin, j.-b., bakker-grunwald, t., and klein, g. (1993) eur. j. biochem. 214, 711-718), these compounds belong to a new class of inositol phosphates in which the cyclitol isomer is neo-inositol. the structures of neo-inositol hexakisphosphate, 2-diphospho-neo-inositol pentakisphosphate, and 2, 5-bisdiphospho ...200010744695
comparison of polyvinyl alcohol fixative with three less hazardous fixatives for detection and identification of intestinal parasites.polyvinyl alcohol (pva) containing the fixative mercuric chloride is considered the "gold standard" for the fixation of ova and parasites in the preparation of permanently stained smears of stool specimens. however, mercuric chloride is potentially hazardous to laboratory personnel and presents disposal problems. we compared three new alternative, nontoxic fixatives with pva, analyzing ease of sample preparation and quality of smears. sixty-eight fresh stool specimens were divided into aliquots ...200010747149
cysteine proteinases and the pathogenesis of amebiasis.amebiasis is a major cause of morbidity and mortality throughout the tropical world. entamoeba histolytica is now recognized as a separate species from the morphologically identical e. dispar, which cannot invade. cysteine proteinases are a key virulence factor of e. histolytica and play a role in intestinal invasion by degrading the extracellular matrix and circumventing the host immune response through cleavage of secretory immunoglobulin a (siga), igg, and activation of complement. cysteine p ...200010755997
pathogenesis of intestinal amebiasis: from molecules to disease.in spite of a wealth of knowledge on the biochemistry and cellular and molecular biology of entamoeba histolytica, little has been done to apply these advances to our understanding of the lesions observed in patients with intestinal amebiasis. in this review, the pathological and histological findings in acute amebic colitis are related to the molecular mechanisms of e. histolytica pathogenicity described to date. infection of the human colon by e. histolytica produces focal ulceration of the in ...200010756002
evidence that hyaluronidase is not involved in tissue invasion of the protozoan parasite entamoeba histolytica.as previous reports suggested that a hyaluronidase is involved in tissue invasion of entamoeba histolytica, we searched for such an activity in trophozoite extracts. a hyaluronidase activity was not detectable in long-term cultures or in amoebae freshly passaged through a gerbil liver, as evidenced by four different techniques.200010769014
a subunit vaccine candidate region of the entamoeba histolytica galactose-adherence lectin promotes interleukin-12 gene transcription and protein production in human macrophages.the cysteine-rich region of the 170-kda subunit galactose-adherence lectin (gal-lectin) of entamoeba histolytica is a subunit vaccine candidate and a protective antigen in the gerbil model of amebiasis. macrophage-mediated immunity is important for protection against e. histolytica and is activated by th1 cytokines. as th1 differentiation is promoted by il-12, we investigated what portion of the gal-lectin could stimulate il-12 in human thp-1 macrophages. native gal-lactin stimulated il-12 p40 / ...200010671197
fluorescence microscopy and fluorescence in situ hybridization of entamoeba histolytica nuclei to analyse mitosis and the localization of repetitive dna. 200010693751
two major 'higher molecular mass proteinases' of entamoeba histolytica are identified as cysteine proteinases 1 and 2. 200010693753
[gastrointestinal diseases associated with hiv infection].a clinical studies were carried out on gastrointestinal diseases associated with hiv infection. during the 6 years between january 1993 and december 1998, 71 hiv infected cases visited to yokohama municipal citizen's hospital, and 26 of them developed gastrointestinal complications during the course of their illness. they consisted of 24 males and 2 females, with the mean age of 44.7 years and the medial value of 42.5 years. of the 26 patients, 21 were japanese, and the remaining 5 were southeas ...200010695296
ectonucleotide diphosphohydrolase activities in entamoeba histolytica.in this work, we describe the ability of living cells of entamoeba histolytica to hydrolyze extracellular atp. in these intact parasites, whose viability was determined by motility and by the eosin method, atp hydrolysis was low in the absence of any divalent metal (78 nmol p(i)/h/10(5) cells). interestingly, in the presence of 5 mm mgcl(2) an ecto-atpase activity of 300 nmol p(i)/h/10(5) cells was observed. the addition of mgcl(2) to the extracellular medium increased the ecto-atpase activity i ...200010700386
rapd in the analysis of isolates of entamoeba histolytica.genetic variability in entamoeba histolytica was analyzed by random amplified polymorphic dna (rapd) using ten arbitrary primers. due to intrinsic characteristics of the rapd technique only axenic samples were analyzed. since the presence of any microorganism in the cultures interfered in the dna profile by generating rapds not pertaining to e. histolytica. the rapd profiles of e. histolytica samples isolated from patients with different clinical manifestations from different regions of the amer ...200010708008
enolase from trypanosoma brucei, from the amitochondriate protist mastigamoeba balamuthi, and from the chloroplast and cytosol of euglena gracilis: pieces in the evolutionary puzzle of the eukaryotic glycolytic pathway.genomic or cdna clones for the glycolytic enzyme enolase were isolated from the amitochondriate pelobiont mastigamoeba balamuthi, from the kinetoplastid trypanosoma brucei, and from the euglenid euglena gracilis. clones for the cytosolic enzyme were found in all three organisms, whereas euglena was found to also express mrna for a second isoenzyme that possesses a putative n-terminal plastid-targeting peptide and is probably targeted to the chloroplast. database searching revealed that arabidops ...200010889212
palladium(ii) complexes of ns donor ligandsderived from s-methyl-dithiocarbazate, s-benzyldithiocarbazateand thiosemicarbazide as antiamoebic agents.synthesis of palladium(ii) complexes of the type [pdlcl(2)] (where l = schiff bases derived from 2-acetylpyridine and s-methyldithiocarbazate, s-benzyldithiocarbazate or thiosemicarbazide) have been isolated by the reaction of [pd(dmso)(2)c1(2)] and respective ligands. the complexes have been characterized by elemental analyses, ir, 1h-nmr, electronic spectra and thermogravimetric analysis. it is concluded that the thionic sulphur and the azomethine nitrogen atoms of the ligands are bonded to th ...200010889327
[intestinal parasitosis and environmental pollution: 1343 pediatric cases in beni-mellal, morocco].this study was undertaken to determine the possible health risk associated with raw wastewater use in agricultural purposes, particularly, the transmission of parasite infections among children of five regions in beni-mellal, morocco. in a randomly-selected sample of 1343 children, 740 of them were from five regions using raw wastewater for agriculture, and 603 were from 4 control regions that do not practice wastewater irrigation. one or more parasite infections were identified in 50.8% of the ...200010894046
refractory enteric amebiasis in pediatric patients with acute graft-versus-host disease after allogeneic bone marrow transplantation. 200010896079
differentiation of entamoeba histolytica and entamoeba dispar cysts using polymerase chain reaction on dna isolated from faeces with spin columns.since entamoeba histolytica and entamoeba dispar were formally recognized as two different species at the world health organization (who)/pan american health organization (paho)/united nations educational, scientific and cultural organization (unesco) meeting in mexico city in 1997, the specific differentiation of the two morphologically identical species would seem relevant in clinical diagnosis. several polymerase chain reaction (pcr)-based methods have been described and used successfully, bu ...200010898137
protection of gerbils from amebic liver abscess by vaccination with a 25-mer peptide derived from the cysteine-rich region of entamoeba histolytica galactose-specific adherence lectin.the protozoan parasite entamoeba histolytica causes extensive morbidity and mortality through intestinal infection and amebic liver abscess. here we show that immunization of gerbils with a single keyhole limpet hemocyanin-coupled 25-mer peptide derived from the 170-kda subunit of the e. histolytica galactose-binding adhesin is sufficient to confer substantial protection against experimentally induced amebic liver abscesses. vaccination provided total protection in 5 of 15 immunized gerbils, and ...200010899838
site-directed mutagenesis of the fructose 6-phosphate binding site of the pyrophosphate-dependent phosphofructokinase of entamoeba histolytica.attempts to define the active site of pyrophosphate-dependent phosphofructokinase (ppi-pfk) using homology modeling based on the three-dimensional structure of the atp-dependent pfks from bacteria have been frustrated by low sequence identity between ppi- and atp-pfks in their carboxyl terminal halves. in the current study, alanine scanning mutagenesis of residues in the carboxyl terminal half of the ppi-pfk of entamoeba histolytica coupled with comparative sequence analysis and computational mo ...200010900132
estimating the impact of amebiasis on health. 200010900473
[amebic liver abscess of autochthonous origin: case report]. 200010905021
entamoeba histolytica: tyrosine kinase activity induced by fibronectin through the beta1-integrin-like molecule.previously, we characterized a 140-kda protein from entamoeba histolytica as a beta1-integrin-like molecule that binds fibronectin. in this work we present data showing that the amoebic receptor is associated with another surface molecule, the 220-kda lectin, and with protein tyrosine kinase activity. by immunoprecipitation with the alphabeta1eh antibody, we demonstrated by immune complex assays for tyrosine protein kinases that the amoebic fibronectin receptor was associated with two phosphoryl ...200010910709
infectious diseases of gastrointestinal tract in adolescents.this article reviews the following gastrointestinal infections: esophagitis, gastritis, duodenitis including duodenal ulcers, and enteritis (gastroenteritis). the epidemiology, risk factors, microbiology and pathogenesis, diagnosis, treatment, morbidity/mortality, and prevention are discussed in relation to the most important pathogens. the symptoms and pathogenesis of esophagitis caused by candida albicans and herpes simplex are contrasted with the symptoms of esophagitis caused by helicobacter ...200010916124
[a case of amebic colitis cured with multiple cicatricial strictures].a 53-year-old male was admitted to gifu red cross hospital with the complaints of diarrhea, abdominal pain, and fever. he had a temperature of 38.4 degrees c and diffuse abdominal tenderness without guarding or rebound. plain film of the abdomen showed marked dilatation of the transverse colon. sigmoidoscopy showed multiple aphthoid erosions and pseudomorphic ulcers, and mucosal biopsies demonstrated numerous trophozoites of entamoeba histolytica. the patient was treated with oral metronidazole ...200010916347
inhibitory and lytic effects of phenothiazine derivatives and related tricyclic neuroleptic compounds, on entamoeba histolytica hk9 and hm1 trophozoites.it has been shown previously that tricyclic neuroleptics like clomipramine and chlorpromazine have lethal effects on leishmania donovani and l. major, and other studies indicate that the phenothiazine inhibitors of trypanothione reductase are potential anti-trypanosomal and anti-leishmanial drugs. with this in mind and our original observation on the presence of trypanothione in entamoeba histolytica hk9, we examined the possible inhibitory effects of various phenothiazine and tricyclic derivati ...200010918039
a tracked approach for automated nmr assignments in proteins (tatapro).a novel automated approach for the sequence specific nmr assignments of 1hn, 13calpha, 13cbeta, 13c'/1halpha and 15n spins in proteins, using triple resonance experimental data, is presented. the algorithm, tatapro (tracked automated assignments in proteins) utilizes the protein primary sequence and peak lists from a set of triple resonance spectra which correlate 1hn and 15n chemical shifts with those of 13calpha, 13cbeta and 13c'/1halpha. the information derived from such correlations is used ...200010921777
antiplasmodial and antiamoebic activities of medicinal plants from sierra leone.crude ethanol extracts of 18 medicinal plants from sierra leone, west africa were examined for antiplasmodial activity against plasmodium falciparum, using an in vitro microtest. eleven of these extracts were also screened for in vitro antiamoebic activity against entamoeba histolytica. only one plant extract, triclisia patens (menispermaceae) showed significant antiplasmodial activity (ic(50) = 8 microg/ml). none of the plant extracts was effective against entamoeba histolytica.200010925402
entamoeba histolytica cysteine proteinases with interleukin-1 beta converting enzyme (ice) activity cause intestinal inflammation and tissue damage in amoebiasis.the protozoan parasite entamoeba histolytica causes intestinal inflammation and ulceration. amoebic trophozoites activate the transcription factor nf-kappa b in human intestinal epithelial cells, initiating an inflammatory response programme with resultant damage to the intestinal tissue. amoebic cysteine proteinases have been proposed as important virulence factors for amoebiasis. to test the role of amoebic cysteine proteinases in the pathogenesis of amoebic colitis, human intestinal xenograft ...200010931347
3'-deoxyribonucleosides and their derivatives as anti-amoebic agents.in general nucleoside analogues were found to possess in vitro amoebicidal property against trophozoites of entamoeba histolytica. the acid-labile nature of these compounds completely destroyed their ability to cure caecal amoebiasis of rats. however the therapeutic efficacy of one of these compounds yielded most promising results, with 10% cures when it was administered as enteric coated formulation.200010601681
differences in substrate specificity and kinetic properties of the recombinant hexokinases hxk1 and hxk2 from entamoeba histolytica.entamoeba histolytica is responsible for amoebic colitis and liver abscess in humans. entamoeba dispar is a closely related, morphologically indistinguishable nonpathogenic species. the hexokinase (atp:d-hexose 6-phosphotransferase, ec 2.7.1.1) isoenzyme patterns distinguish the pathogenic and nonpathogenic species. both species possess two hexokinases with very similar molecular mass and different isoelectric points. in order to understand the role of the two different isoenzymes from e. histol ...200010613700
partial characterization of a 36-kda antigen of entamoeba histolytica and its recognition by sera from patients with amoebiasis.a 36-kda antigen of axenically grown pathogenic entamoeba histolytica (hm1-imss) was eluted from the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page)-resolved crude amoebic extract antigens. the immunoreactivity of this partially purified 36-kda antigen with monoclonal antibody (moab) 3d(10) altered significantly (p<0.01) after heat and trypsin treatment but remained unaltered after treatment with sodium metaperiodate (p0.5), thereby indicating the protein nature of the epito ...200010617786
development of a deltaglna balanced lethal plasmid system for expression of heterologous antigens by attenuated vaccine vector strains of vibrio cholerae.we have previously shown that more prominent immune responses are induced to antigens expressed from multicopy plasmids in live attenuated vaccine vector strains of vibrio cholerae than to antigens expressed from single-copy genes on the v. cholerae chromosome. here, we report the construction of a deltaglna derivative of v. cholerae vaccine strain peru2. this mutant strain, peru2deltaglna, is unable to grow on medium that does not contain glutamine; this growth deficiency is complemented by pke ...200010603391
innate immunity to amebic liver abscess is dependent on gamma interferon and nitric oxide in a murine model of disease.evidence from in vitro studies suggests that gamma interferon (ifn-gamma) and nitric oxide (no) are important in host defense against the protozoan parasite entamoeba histolytica. we used scid mice with targeted disruption of the ifn-gamma receptor gene and mice with targeted disruption of the gene encoding inducible no synthase to show that ifn-gamma plays a role in the innate immunity to amebic liver abscess seen in scid mice while no is required for control of amebic liver abscess in immunoco ...200010603416
extracellular matrix-induced signaling in entamoeba histolytica: its role in invasiveness.entamoeba histolytica trophozoites can invade the mucosa of the host large intestine to cause disease. here, isaura meza describes recent work indicating that the trophozoites respond to the binding of extracellular matrix proteins by activating receptor-mediated signal transduction pathways. activation of phosphokinase c or adenylyl cyclase induces protein phosphorylation, actin gene expression and reorganization of the actin cytoskeleton to form adhesive structures that promote interaction wit ...200010637584
granulysin: a novel antimicrobial peptide of cytolytic t lymphocytes and natural killer cells.granulysin is a novel antimicrobial protein produced by human cytolytic t lymphocytes and natural killer cells. it is active against a broad range of microbes, including gram-positive and gram-negative bacteria, fungi, and parasites. the fact that it kills mycobacterium tuberculosis is particularly important, since the current vaccine (bacille calmette-guerin, bcg) is of limited efficacy and antibiotic resistance is increasing. although functionally related to other antibacterial peptides, defen ...200010644038
comparison of antigen-capture elisa to stool-culture methods for the detection of asymptomatic entamoeba species infection in kafer daoud, egypt.we performed a prospective field study in the village of kafer daoud in menofia, egypt to compare the fecal culture method with enzyme linked immuno assay (elisa) for detection of 170 kda lectin antigen in feces for diagnosis of asymptomatic entamoeba histolytica and entamoeba dispar infection. all subjects with e. histolytica or e. dispar infection detected by culture also had positive elisa for amebic antigen in their feces and an additional 57 entameoba infections missed by culture were detec ...200011289667
serodiagnosis of amoebiasis using a recombinant protein fragment of the 29 kda surface antigen of entamoeba histolytica.to develop an improved serodiagnostic test for amoebiasis, we performed a detailed analysis of the immunodominant epitopes of the 29 kda surface antigen and evaluated its sensitivity and specificity. enzyme-linked immunosorbent assay (elisa) based on the fragment containing the immunodominant epitope was evaluated further and compared with full-length recombinant 29 kda protein. specificity and sensitivity of the two elisas were assessed using 55 human sera of parasitic protozoa infection cases ...200011428340
intestinal parasites infestation and anemia in primary school children in gaza governorates--palestine.a comparative study was carried out to identify the prevalence of anemia, nutritional indices and intestinal parasitic infestation in primary school children. the target population included 209 pupils aged 6-11 years, attending schools in two areas, rimal area (urban) and jabalia village (rural), in gaza governorates. prevalence of intestinal parasites was high in jabalia village (more than 53%) in comparison to rimal area (33%). the main intestinal parasites were entamoeba histolytica, giardia ...200011845471
recent developments in amoebiasis research.invasive amoebiasis, the infection of humans by entamoeba histolytica associated with dysentery and liver abscess, is still a major cause of morbidity and mortality in developing countries. this review attempts to reduce the gap between the overwhelming amount of information coming recently from laboratory research and the sparse contributions resulting from clinical and epidemiological investigations of the second parasitic cause of death resulting from a protozoan parasite.200011964813
the application of the atomic force microscope to studies of medically important protozoan parasites.both living and fixed specimens of the medically-important parasitic protozoa, trypanosoma cruzi, toxoplasma gondii, giardia lamblia, entamoeba histolytica, and acanthamoeba spp. were studied by atomic force microscopy (afm). the preparation of fixed specimens was similar to methods used for either scanning or transmission electron microscopy. afm scanning was performed using both contact and tapping modes. a classical fixation procedure utilizing glutaraldehyde followed by ethanol dehydration w ...200011108031
two novel calcium-binding proteins from cytoplasmic granules of the protozoan parasite entamoeba histolytica.we report on the molecular characterisation of two novel granule proteins of the protozoon and human pathogen entamoeba histolytica. the proteins, which were named grainin 1 and 2, show a considerable structural similarity to calcium-binding proteins, particularly within ef-hand motifs. each grainin possesses three of these putative calcium-binding sites. based on careful inspection of known structures of protein families containing ef-hands, a domain of grainin 1 covering two ef-hand motifs was ...200011113449
[bacteriological quality of human drinking water in high-margination zones in chiapas].to analyze the bacteriological quality of drinking water (bqdw) and its association with diarrhoea and intestinal parasites in children 1 to 14 years old, in areas of high levels of poverty in chiapas, mexico.200011125624
socioeconomic status, clinical features, laboratory and parasitological findings of hepatic amebiasis patients--a hospital based prospective study in bangladesh.socioeconomic status, clinical, laboratory and parasitological features of 31 hospitalized amebic liver abscess (ala) and 8 amebic hepatitis (ah) patients were studied. thirty-seven (94.9%) of the total 39 cases were from low socioeconomic class and 2 (5.1%) were from middle class (p<0.001). sixteen (51.6%) ala and 5 (62.5%) ah patients were admitted with duration of disease for 3 weeks or more. twenty-one (67.7%) ala and 3 (37.5%) ah cases gave no previous history of diarrhea or dysentery. epig ...200011127347
auxotrophy to lipoproteins of entamoeba histolytica cultivated under axenic conditions.entamoeba histolytica grows in media without serum but with a mixture of aminoacids, vitamins, lipoproteins, free cholesterol, phospholipids and fatty acids called pacsr. the ability of lipoproteins and free lipids to support growth of three e. histolytica strains (hk9, hmi:imss and hm3:imss) was analysed. tubes containing 5 ml culture medium, amino acids, vitamins and either 120-1,200 microg lipoproteins/ml or 0.017-0.10 mg free lipids/ml (predissolved in absolute ethanol) were inoculated with ...200011133106
recent developments in amoebiasis:the gal/galnac lectins of entamoeba histolytica and entamoeba dispar.amoebiasis is responsible for 50000-100000 deaths annually. invasive amoebic disease begins with the attachment of entamoeba histolytica trophozoites to colonic mucin, a process mediated by the amoebic gal/galnac lectin. the non-pathogenic counterpart, e. dispar, is morphologically identical but genetically distinct. investigations comparing the gal/galnac lectin from these two organisms are under way.200011137050
[a case of aids complicated with liver tuberculosis].we experienced a double infection of tuberculosis and amebiasis of the liver. a 28 year old male with aids was admitted to our hospital because of severe diarrhea and liver abscess by entamoeba histolytica. in spite of improvement of the diarrhea and liver abscess by the therapy against e. historicica, serum levels of gamma-gtp and alp remained high and hepatosplenomegaly gradually increased. a liver biopsy was performed. pathology showed a granulomatous lesion with langhans' giant cells. from t ...200011140084
experimental amebiasis: immunohistochemical study of immune cell populations.distribution of immune cell populations was studied in a c3h/hej mouse model of intestinal amebiasis from 5 to 60 days post-inoculation with entamoeba histolytica, using immunoperoxidase techniques. at various time intervals, the ceca from mice were fixed in 10% formalin, dehydrated, embedded and sectioned at 5 microm. sections were incubated with conjugated peroxidase-labelled antibodies to mouse iga, igm, and igg. color was developed with 3, 3'-diaminobenzidine tetrahydrochloride (dab)/h2o2 so ...200011140454
in vitro antiplasmodial, antiamoebic, and cytotoxic activities of some monomeric isoquinoline alkaloids.twenty-one alkaloids have been assessed for activities against plasmodium falciparum (multidrug- resistant strain k1) in vitro; 18 of these are reported for the first time. two protoberberine alkaloids, dehydrodiscretine and berberine, were found to have antiplasmodial ic(50) values less than 1 m, while seven alkaloids-allocrytopine, columbamine, dehydroocoteine, jatrorrhizine, norcorydine, thalifendine, and ushinsunine-had values between 1 and 10 m. these results are discussed in the context of ...200011141105
purification and properties of an acid phosphatase from entamoeba histolytica hm-1:imss.entamoeba histolytica contains and secretes acid phosphatase, which has been proposed as a virulence factor in some pathogenic microorganisms. in this work, we purified and characterised a membrane-bound acid phosphatase (map) from e. histolytica hm-1:imss and studied the effect of different chemical compounds on the secreted acid phosphatase and map activities. map purification was accomplished by detergent solubilisation, and affinity and ion exchange chromatographies. the enzyme showed a pi o ...200010779571
cloning, characterization and functional expression of a cyclophilin of entamoeba histolytica.full-length entamoeba histolytica cyclophilin gene (ehcyp) was isolated, characterized and recombinantly expressed in bacterial cells. the deduced amino acid sequence of ehcyp shows 60-70% identity with cyclophilins from other organisms and has conserved the cyclophilin signature motifs and residues involved in cyclosporin a binding. upstream of the 501 bp open reading frame of ehcyp, sequences resembling the putative consensus e. histolytica ce1, ce2 and ce3 regulatory elements were found. nort ...200010779598
cloning and characterization of entamoeba histolytica antigens recognized by human secretory iga antibodies.to identify the entamoeba histolytica antigens capable of inducing secretory iga (siga) responses in humans, a cdna library from the strain hm1:imss was immuno-screened with saliva from patients with intestinal amebiasis or amebic liver abscess. clones isolated with siga antibodies from patients with intestinal amebiasis corresponded to the known serine-rich protein isoform, a 29 kda cysteine-rich protein and 1-alpha elongation factor. clones corresponding to enolase, cyclophilin, ribosomal prot ...200010780744
antiamoebic and spasmolytic activities of extracts from some antidiarrhoeal traditional preparations used in kinshasa, congo.three major extracts from some traditional preparations, based on medicinal plants, used as antidiarrhoeal agents were investigated for their putative antiamoebic and spasmolytic activities in vitro. results indicated that both biological activities are concentrated in the polyphenolic fraction, and not in the saponin or alkaloid containing fractions. the most active polyphenolic extracts were those from euphorbia hirta whole plant, leaves of alchornea cordifolia, crossopteryx febrifuga, nauclea ...200010782488
isolation of emetine resistant clones of entamoeba histolytica by petri dish agar method.emetine resistant clones of entamoeba histolytica strain hm1:imss were isolated by using petri dish agar method after mutation with ethyl-methanesulphonate. two emetine resistant clones were obtained and both were resistant to emetine at a concentration of 24 micrograms/ml of emetine. the 50 per cent inhibitory concentration (ic50) for both emetine sensitive and resistant clones was 5 and 14 micrograms/ml respectively. the colony forming efficiency of e. histolytica strain hm1:imss varied from 4 ...200010793488
inhibition of gene expression in entamoeba by the transcription of antisense rna: effect of 5' and 3' regulatory elements.down regulation of gene expression by antisense rna is one of the ways to investigate the specific contribution of certain components to the physiology and activities of a cell. a successful inhibition of gene expression in entamoeba trophozoites was achieved in stable transfectants by using hybrid plasmid constructs containing promotors that produce transcripts which do not bind to polysomes. different promotors were found to be required for entamoeba histolytica or entamoeba dispar. in e. hist ...200010717304
compositional pressure and translational selection determine codon usage in the extremely gc-poor unicellular eukaryote entamoeba histolytica.it is widely accepted that the compositional pressure is the only factor shaping codon usage in unicellular species displaying extremely biased genomic compositions. this seems to be the case in the prokaryotes mycoplasma capricolum, rickettsia prowasekii and borrelia burgdorferi (gc-poor), and in micrococcus luteus (gc-rich). however, in the gc-poor unicellular eukaryotes dictyostelium discoideum and plasmodium falciparum, there is evidence that selection, acting at the level of translation, in ...200010721724
the major surface antigens of entamoeba histolytica trophozoites are gpi-anchored proteophosphoglycans.trophozoites of the parasitic protozoa, entamoeba histolytica, synthesize a cell surface lipoglycoconjugate, termed lipophosphoglycan, which is thought to be an important virulence factor and potential vaccine candidate against invasive amebiasis. here, we show that the e. histolytica lipophosphoglycans are in fact glycosylphosphatidylinositol (gpi)-anchored proteophosphoglycans (ppgs). these ppgs contain a highly acidic polypeptide component which is rich in asp, glu and phosphoserine residues. ...200010715210
entamoeba dispar, but not e. histolytica, detected in a colony of chimpanzees in japan.chimpanzees (pan troglodytes) residing in the kumamoto primate research park, sanwa kagaku kenkyusho, were surveyed for the presence of intestinal parasites. stool samples from 107 chimpanzees were examined by microscopy after formalin-ether sedimentation. of these animals, 100 were infected with at least 1 species of ameba. the positivity rates recorded were as follows: entamoeba coli, 88%; e. histolytica/e. dispar, 48%; e. hartmanni, 15%; iodamoeba buetschlii, 8%; endolimax nana, 4%; and entam ...200010935902
interaction of antibodies with entamoeba histolytica trophozoites from experimental amebic liver abscess: an immunocytochemical study.using immunocytochemical techniques, we studied the interaction of antibodies with entamoeba histolytica trophozoites present during the development of amebic liver abscess. hamsters were intrahepatically inoculated with hm1-imss axenic amebas and sacrificed at different days post-inoculation. igg of rabbit anti-e. histolytica and igg of rabbit anti-igg of hamster were used, both labeled with peroxidase. with the rabbit anti-e. histolytica, all trophozoites present in hepatic lesions from 1-7 da ...200010935913
contribution to the ethnobotanical, phytochemical and pharmacological studies of traditionally used medicinal plants in the treatment of dysentery and diarrhoea in lomela area, democratic republic of congo (drc).in order to collect ethnobotanical information about antidiarrhoeal plants, we performed inquiries among traditional healers, community leaders, and native people of lomela villages in congo. six medicinal plants widely used in this region were designated as having antidysenteric and antidiarrhoeal properties. these six medicinal plants were screened for groups of phytochemical compounds with antibacterial and antiamoebic activities. they were found to contain tannins, alkaloids, saponins, flavo ...200010940578
intestinal parasites in relation to haemoglobin level and nutritional status of school children in gaza.the prevalence of intestinal parasites and their relations to anaemia and nutritional status among school children aged 6-11 years in gaza was studied. the target area is overcrowded with improper sewage disposal system and low socioeconomic levels. anaemia was assessed by haemoglobin level (hb) and nutritional status by anthropometric measurements including weight for age (wa), weight for height (wh) and height for age (ha). intestinal parasites were found to be prevalent in gaza. the overall p ...200010946498
a mitochondrion in entamoeba histolytica? 200010951594
[genetic differentiation with restriction patterns between pathogenic and non-pathogenic monoxenic entamoeba histolytica].cysteine-proteinase of entamoeba histolytica have been considered implicated like important virulence factors in the pathogenesis of amebiasis. on the basis of the differences in ethnic gene that encodes to 30 kda proteinase. the present study validated a strategy to differentiate strains of pathogenic and non-pathogenic entamoeba histolytica by restriction patterns.200010953608
[a recurrent case of amebic liver abscess seventeen years after the first occurrence].a 49-year-old male who had been diagnosed as having amebic liver abscess when he was 32-year-old was admitted to our hospital with fever and watery diarrhea. ultrasonography and ct examination demonstrated a solitary abscess in the right lobe of the liver. cysts of entamoeba histolytica were detected in the stool and an aspiration of the liver abscess looked like anchovy paste. serum amebic antibody by the ifa method was positive and the case was diagnosed as amebic liver abscess. the patient wa ...200010965662
[a case of amebic liver abscess ruptured into the stomach]. 200010965760
antibacterial, anthelmintic and anti-amoebic activity in south african medicinal plants.hexane, ethanol and water extracts of plants used by south african traditional healers for treating stomach ailments were screened for antibacterial, anthelmintic and anti-amoebic activities. to evaluate antibacterial activity, the disc-diffusion assay was used against several gram-positive and gram-negative species. minimal inhibitory concentration values were determined with a microdilution assay. ethanolic extracts showed the greatest activity, and gram-positive bacteria were the most suscept ...200010967478
diagnosis of amebic liver abscess and intestinal infection with the techlab entamoeba histolytica ii antigen detection and antibody tests.a noninvasive diagnostic test for amebic liver abscess is needed, because amebic and bacterial abscesses appear identical on ultrasound or computer tomography and because it is rarely possible to identify entamoeba histolytica in stool specimens from patients with amebic liver abscess. here we report a method of detection in serum of circulating e. histolytica gal/galnac lectin to diagnose amebic liver abscess, which was used in patients from dhaka, bangladesh. the techlab e. histolytica ii test ...200010970364
detection of giardia lamblia, entamoeba histolytica/entamoeba dispar, and cryptosporidium parvum antigens in human fecal specimens using the triage parasite panel enzyme immunoassay.the triage parasite panel (biosite diagnostics, san diego, calif.) is a new qualitative enzyme immunoassay (eia) panel for the detection of giardia lamblia, entamoeba histolytica/e. dispar, and cryptosporidium parvum in fresh or fresh, frozen, unfixed human fecal specimens. by using specific antibodies, antigens specific for these organisms are captured and immobilized on a membrane. panel performance was evaluated with known positive and negative stool specimens (a total of 444 specimens) that ...200010970380
intestinal parasitic infections in an institution for the mentally retarded.of 550 mentally retarded patients in an italian institution, 125 (23%) were found to be infected with intestinal parasites. the infections were most frequent in young men, those with severe mental retardation, the chronically institutionalized and those living in older wards. ninety-four (75.2%) of the parasitised subjects were infected only with protozoa, 25 (20%) only with helminths, and six (4.8%) with protozoa and helminths. entamoeba histolytica and e. dispar infections were detected, but a ...200010983558
amoebic liver abscess in hiv-infected patients. 200010985335
amebic liver abscess.amebiasis is a widespread parasitic disease caused by entamoeba histolytica. this protozoan organism is the third leading parasitic cause of death in the developing world and is an important health risk to travelers in endemic areas. amebiasis most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients may develop intestinal invasive disease or extraintestinal disease-amebic liver abscess being the most common extraintestinal manifestation. this article re ...200010987110
a mitochondrial-type hsp70 gene of entamoeba histolytica. 200010989156
[human infestation by entamoeba histolytica. autochthonous disease in our region? report of a case]. 200010994360
percutaneous catheter drainage in drug-resistant amoebic liver abscess.this communication records our experience with the percutaneous catheter drainage (pcd) of 22 amoebic liver abscesses in 19 patients who had failed to respond to amoebicidal therapy. in one patient with a left lobe abscess, imminent rupture was an additional indication for drainage. pcd combined with amoebicidal therapy not only expedited recovery, but was curative in all 19 patients. there were no complications. we conclude that pcd is a most useful adjunct to drug therapy and recommend its rou ...200010995100
the amoebapore superfamily.amoebapores, synthesized by human protozoan parasites, form ion channels in target cells and artificial lipid membranes. the major pathogenic effect of these proteins is due to their cytolytic capability which results in target cell death. they comprise a coherent family and are homologous to other proteins and protein domains found in eight families. these families include in addition to the amoebapores (1) the saposins, (2) the nk-lysins and granulysins, (3) the pulmonary surfactant proteins b ...200010998571
the primordial high energy compound: atp or inorganic pyrophosphate?the pyrophosphate-dependent phosphofructokinase (pp(i)-pfk) of entamoeba histolytica displays a million fold preference for inorganic pyrophosphate (pp(i)) over atp (calculated as the ratio of k(cat)/k(m)). the introduction of a single mutation by site-directed mutagenesis changes its preference from pp(i) to atp. the single mutant has an 8-fold preference for atp whereas a related double mutant shows a preference exceeding 10,000-fold. the results suggest the presence of a latent nucleotide bin ...200011001940
direct amplification of entamoeba histolytica dna from amoebic liver abscess pus using polymerase chain reaction.an important and serious complication of intestinal infection with entamoeba histolytica is the involvement of the liver (hepatic amoebiasis). hepatic amoebiasis is usually diagnosed by the clinical picture (pain in the right upper quadrant and fever), ultrasound examination and positive serology. however, none of these tests are definitive and the picture overlaps with pyogenic liver abscess caused by bacteria. it is for this reason that the feasibility of using polymerase chain reaction (pcr) ...200011002979
immunoblot analysis of iga antibodies to naegleria fowleri in human saliva and serum.the objective of this study was to evaluate the secretory iga (siga) antibody response to naegleria fowleri (nf) in individuals living in a parasite endemic area. saliva and serum samples were obtained from both healthy subjects and patients suffering from a respiratory illness (chronic bronchitis or rhinitis) and were analyzed by immunoblot assay. siga from the patients' samples recognized more intensely a greater number of nf proteins than did siga from the healthy control group. the proteins ...200011002989
identification of enteric pathogens in hiv-positive patients with diarrhoea in northern india.enteric pathogens associated with chronic diarrhoea in hiv-positive patients were studied. the study was conducted during january 1995-december 1998. stool specimens from all diarrhoea patients (n = 26) were examined microscopically for ova and parasites using wet preparations and stained smears. stool samples from diarrhoea patients were also cultured on appropriate media to isolate enteric bacterial pathogens. of the 59 patients, 26 (44%) had prolonged diarrhoea for more than 4 weeks. enteric ...200011014766
molecular epidemiology of entamoeba spp.: evidence of a bottleneck (demographic sweep) and transcontinental spread of diploid parasites.entamoeba histolytica causes amebic colitis and liver abscess in developing countries such as mexico and india. entamoeba dispar is morphologically identical but is not associated with disease. here we determined the ploidy of e. histolytica and developed pcr-based methods for distinguishing field isolates of e. histolytica or e. dispar. fluorescence in situ hybridization showed that e. histolytica trophozoites are diploid for five "single-copy" probes tested. intergenic sequences between supero ...200011015408
immunodulation of rat serum and mucosal antibody responses to entamoeba histolytica trophozoites by beta-1,3-glucan and cholera toxin.systemic and mucosal and immune responses can be manipulated with immunomodulators. here we show the modulatory effects of cholera toxin (ct) and beta-1,3-glucan (glu) on the rat antiamebic serum and fecal antibody responses to one or four intraperitoneal (ip) or intragastric (ig) doses of glutaraldehyde-fixed entamoeba histolytica trophozoites (gft). one ip dose of gft maximized serum igm and igg antiamebic antibodies on days 4 and 9, respectively; ct coadministration increased igm antibodies, ...200011027459
[diagnosis of intestinal amebiasis using coproscopic and immunological methods in a population sample in greater metropolitan belém, pará, brazil].we compare diagnostic methods for entamoeba histolytica in fecal samples from the city of belém, pará, brazil. we analyze stool samples from children and adults (group i); stool and serum samples from adults (group ii); and stool samples from children (group iii). in groups i and iii, we used direct examination with lugol (dm), faust et al (fm), and elisa (detection of e. histolytica anti-giap coproantigen) and in group ii, dm, iron hematoxylin staining (ihs), fm, elisa, and the indirect immunof ...200011035523
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