Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| clinical and pathophysiological aspects of immune complex glomerulonephritis associated with entamoeba histolytica abscess of the liver. | 1997 | 9332542 | |
| allicin from garlic strongly inhibits cysteine proteinases and cytopathic effects of entamoeba histolytica. | the ability of entamoeba histolytica trophozoites to destroy monolayers of baby hamster kidney cells is inhibited by allicin, one of the active principles of garlic. cysteine proteinases, an important contributor to amebic virulence, as well as alcohol dehydrogenase, are strongly inhibited by allicin. | 1997 | 9333064 |
| [cdnas encoding the antigenic proteins in pathogenic strain of entamoeba histolytica]. | the differential display reverse transcription polymerase chain reaction (ddrt-pcr) analysis was performed to identify the pathogenic strain specific amplicons. mrnas were purified from the trophozoites of the pathogenic strain ys-27 and the non-pathogenic strain s 16, respectively. three kinds of first stranded cdnas were reverse transcribed from the mrnas by one base anchored oligo-dt11m (m: a, c, or g) primers. each cdna template was used for ddrt-pcr analysis. a total of 144 pathogenic strai ... | 1997 | 9335186 |
| progress towards development of a vaccine for amebiasis. | the application of molecular biologic techniques over the past decade has seen a tremendous growth in our knowledge of the biology of entamoeba histolytica, the causative agent of amebic dysentery and amebic liver abscess. this approach has also led to the identification and structural characterization of three amebic antigens, the serine-rich entamoeba histolytica protein (srehp), the 170-kda subunit of the gal/galnac binding lectin, and the 29-kda cysteine-rich protein, which all show promise ... | 1997 | 9336666 |
| protection against invasive amebiasis by a single monoclonal antibody directed against a lipophosphoglycan antigen localized on the surface of entamoeba histolytica. | a panel of monoclonal antibodies was raised from mice immunized with a membrane preparation from entamoeba histolytica, the pathogenic species causing invasive amebiasis in humans. antibody eh5 gave a polydisperse band in immunoblots from membrane preparations from different e. histolytica strains, and a much weaker signal from two strains of the nonpathogenic species entamoeba dispar. although the exact chemical structure of the eh5 antigen is not yet known, the ability of the antigen to be met ... | 1997 | 9348313 |
| infectious diarrhoea--an update. | infectious diarrhoea is one of the most common illness affecting mankind. recent advancement have led to detailed understanding of causative agents and the pathogenesis of the infections. fluid and electrolyte replacement remains the most important aspect of treatment. the role of antimicrobial agents is discussed. | 1997 | 9355725 |
| is it curtains for chronic amebiasis? | 1997 | 9357181 | |
| does entamoeba histolytica cause irritable bowel syndrome? | symptoms of patients with irritable bowel syndrome (ibs) closely mimic those of patients with non-dysenteric amebic colitis. | 1997 | 9357182 |
| metronidazole. a therapeutic review and update. | the nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most gram-negative and gram-positive anaerobic bacteria. metronidazole has activity against protozoans like entamoeba histolytica, giardia lamblia and trichomonas vaginalis, for which the drug was first approved as an effective treatment. anaerobic bacteria which are typically sensitive are primarily gram-negative anaerobes belonging to the bacteroides and fusobacterium spp. gra ... | 1997 | 9360057 |
| intestinal parasitic infections in patients with malignancy. | the frequency of intestinal parasitic infections was studied retrospectively in 1,029 cancer patients presenting with symptoms of diarrhoea. intestinal parasites were diagnosed by stool examination, using both the direct and concentration techniques and also the modified acid fast stain. parasitic infection was found in 16.5% of the cases. the majority of the patients with intestinal parasitosis had cancer of the haemopoietic system and were on anticancer chemotherapy. the most prevalent parasit ... | 1997 | 9360344 |
| sensitivity of entamoeba histolytica and entamoeba dispar patient isolates to human complement. | twenty-one entamoeba histolytica and 56 entamoeba dispar patient isolates were investigated for their sensitivity to the classical and alternative pathway of human complement, e. histolytica and e. dispar patient isolates were differentiated by polymerase chain reaction and hexokinase isoenzyme typing. it was found that 90.3% (+/- 12.0%) of the trophozoites of e. histolytica were lysed after 30 min by the alternative pathway of complement in the presence of 50% human serum (19 isolates showed ly ... | 1997 | 9364556 |
| monoclonal antibodies multireactive with parasite antigens produced by hybridomas generated from naive mice. | hybridoma clones producing igm naturally occurring (natural) antibodies were generated from naive balb/c mice and characterized for reactivity against parasite antigens. ascites of mice injected with these hybridomas reacted with toxoplasma gondii soluble antigen at levels approximately 1000-10,000 times higher than serum pooled from mice used for generating hybridomas as determined by a conventional enzyme-linked immunosorbent assay. western blot analysis indicated that these monoclonal antibod ... | 1997 | 9364565 |
| entamoeba histolytica: computer-assisted modeling of phosphofructokinase for the prediction of broad-spectrum antiparasitic agents. | pyrophosphate-dependent phosphofructokinase (ppi-pfk) is the rate-limiting glycolytic enzyme found in the pathogenic protists entamoeba histolytica, giardia lamblia, toxoplasma gondii, trichomonas vaginalis, and naegleria fowleri. the enzyme differs significantly from atp-dependent phosphofructokinases found in humans and as such represents an important drug target. current therapy for infections caused by these pathogens is inadequate, especially for children, pregnant women, and the immune com ... | 1997 | 9371084 |
| gene amplification in entamoeba histolytica. | we show here data suggesting that entamoeba histolytica, the protozoan responsible for human amebiasis, presents dna amplification in a fashion similar to that described for transformed mammalian cells. by transmission electron microscopy (tem), we found linear, circular and concentric circular dna molecules exhibiting the main events of the unscheduled dna amplification process. loops were formed after the recombination of two nonadjacent dna regions, and bubbles appeared from the recombinant s ... | 1996 | 9371226 |
| usefulness of new dna extraction procedure for pcr technique in species identification of entamoeba isolates. | in this study we have developed a modified clark and diamond (1992, 1993) method using the polymerase chain reaction to amplify amoebic ribosomal rna genes that allow either specific detection of entamoeba histolytica s. str. or amoeba species identification. dna was isolated from cultured protozoa or from stool samples (cysts and/or trophozoites). cultures of xenic or axenic material (also stool samples) were treated with easy genomic dna prep or genomic dna prep plus (a&a biotechnology, poland ... | 1997 | 9374591 |
| endoplasmic reticulum and golgi-like elements in entamoeba. | the cytoplasm of entamoeba is characterized by the presence of a large number of vesicles of different size and shape. previous electron microscopic studies have not clearly revealed the presence of the endoplasmic reticulum and the golgi complex. in the present study two approaches were used aimed at the identification of these two structures in trophozoites of entamoeba moshkovskii and entamoeba histolytica: (a) cytochemical techniques associated with transmission electron microscopy, such as ... | 1997 | 9377074 |
| peroxidase activity of a tsa-like antioxidant protein from a pathogenic amoeba. | the 29 kda surface protein of entamoeba histolytica is an abundant antigenic protein expressed by pathogenic strains of this organism. the protein is a member of a widely-dispersed group of homologues which includes at least two cysteinyl peroxidases, salmonella typhimurium alkyl hydroperoxidase c-22 protein (ahpc) and saccharomyces cerevisiae thiol-specific antioxidant protein (tsa). here, for the first time in a pathogenic eukaryote, we have demonstrated that the amoebic protein also possesses ... | 1997 | 9378375 |
| epidemiologic features of intestinal parasitic infections in italian mental institutions. | to determine the prevalence of intestinal parasitic infections in the residents of four italian psychiatric institutions, we examined the stool specimens collected in triplicate from 238 residents, enrolled between may 1995 and may 1996. besides, physician and staff nurses provided data about each resident by standardized questionnaires. parasites were detected in the fecal samples from 128 patients (53.8%). however, in the stool specimens from 106 residents only non-pathogenic protozoa were fou ... | 1997 | 9384273 |
| application of polymerase chain reaction for diagnosing amebic liver abscess. | polymerase chain reaction (pcr) has been applied in diagnosing amebic liver infection by detecting pathogenic entamoeba histolytica dna in liver aspirates. oligonucleotide primers found to be specific for the gene encoding the 30 kda molecule of this pathogenic ameba were used in the test. liver aspirates obtained from 23 patients with amebic liver abscess substantiated by typical clinical manifastation or with very high titres of anti-e histolytica antibodies by elisa were found to be positive ... | 1996 | 9387418 |
| molecular methods for diagnosis and epidemiological studies of parasitic infections. | direct microscopy is widely used for the diagnosis of parasitic infections although it often requires an experienced microscopist for accurate diagnosis, is labour intensive and not very sensitive. in order to overcome some of these shortcomings, molecular or nucleic acid-based diagnostic methods for parasitic infections have been developed over the past 12 years. the parasites which have been studied with these techniques include the human plasmodia, leishmania, the trypanosomes, toxoplasma gon ... | 1997 | 9394184 |
| virulence parameters in the characterization of strains of entamoeba histolytica. | differences in virulence of strains of entamoeba histolytica have long been detected by various experimental assays, both in vivo and in vitro. discrepancies in the strains characterization have been arisen when different biological assays are compared. in order to evaluate different parameters of virulence in the strains characterization, five strains of e. histolytica, kept under axenic culture, were characterized in respect to their, capability to induce hamster liver abscess, erythrophagocyt ... | 1997 | 9394517 |
| effect of intestinal parasite treatment on the efficacy of oral iodized oil for correcting iodine deficiency in schoolchildren. | oral supplementation with iodized oil for correction of iodine deficiency in a population has advantages over intramuscular injection but the duration of effect is shorter. the relation of intestinal parasite treatment and efficacy of oral iodized oil was examined in an intervention study in 8-10-y-old schoolchildren in malawi. severely iodine-deficient schoolchildren with a single parasitic infestation of ascaris lumbricoides (n = 44), hookworm (n = 42), or entamoeba histolytica (n = 24) were r ... | 1997 | 9394695 |
| fibronectin-derived fragments as inducers of adhesion and chemotaxis of entamoeba histolytica trophozoites. | active migration of entamoeba histolytica trophozoites through extracellular matrixes might play a role in host tissue destruction. trophozoites degrade soluble fibronectin (fn) bound to their surface and adhere to substrate-bound fn, producing local degradation. fn proteolytic fragments were used to determine the nature of adhesion and motility-promoting domains within the protein. the 70-kda fragment (amino-terminal end) promoted the highest adhesion, followed by the 120-kda fragment, which co ... | 1997 | 9395373 |
| epidemiological study on infectious diarrheal diseases in children in a coastal rural area of kenya. | diarrheal diseases are major causes of morbidity and mortality among children in developing countries. we have analyzed the causative agents of diarrhea in children under five years of age who resided in rural environments but attended a hospital in malindi, a coastal town in kenya. bacterial diarrhea was found in 239 (27.7%) of 862 patients with diarrhea. diarrheagenic escherichia coli, including enteropathogenic, enterotoxigenic, and enterohaemorrhagic strains, was isolated from 119 (13.8%) pa ... | 1997 | 9403500 |
| a new gene family (ariel) encodes asparagine-rich entamoeba histolytica antigens, which resemble the amebic vaccine candidate serine-rich e. histolytica protein. | a family of genes, called ariel, are named for and encode asparagine-rich entamoeba histolytica antigens containing 2 to 16 octapeptide repeats. ariel proteins, which are constitutively expressed by trophozoites, belong to a large antigen family that includes the serine-rich e. histolytica protein (srehp), an amebic vaccine candidate. | 1998 | 9423879 |
| amebiasis in schistosomiasis endemic and non-endemic areas in egypt. | stool and blood specimens were collected from each of 404 and 576 individuals at sindbis village (qualiubia governorate) in the nile delta where schistosomiasis is endemic and el-rashda village (new valley governorate) in the western desert of egypt where there is no schistosomiasis; respectively. based on the microscopical examination of stool specimens, the prevalence of infection with entamoeba (e. histolytica and/or e. dispar which are morphologically indistinguishable) was higher at sindbis ... | 1997 | 9425808 |
| blastocystis hominis among apparently healthy food handlers in jeddah, saudi arabia. | a prospective study was carried out to investigate the prevalence of blastocystis hominis among random sample of apparently healthy food handlers. a total of 250 non saudi males over 21 years of age were examined. ninety (36%) had pathogenic and non pathogenic intestinal parasites. a total of 143 parasites were detected in their stool specimens. twenty were b. hominis (13.99%) while other parasites were 123 (86.01%). b. hominis was found in 20 positive cases (22.22%) with an overall rate of 8%. ... | 1997 | 9425825 |
| characterization for virulence of an axenic strain of entamoeba histolytica: evidence for overexpression of two proteins. | the pattern of protein from membrane and crude homogenate of entamoeba histolytica strain 462 axenically cultivated (462ac) and submitted to hamster liver passage (462hp) was obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the substrains 462ac and 462hp were compared by zymodeme analysis, erythrophagocytosis, cytopathic effect upon mammalian cells and the capability to induce abscess in hamster liver. the results showed no differences for erythrophagocytosis, cytopathic ef ... | 1997 | 9428571 |
| [presence of various pathogenic microorganisms in fresh vegetables in costa rica]. | this study reports the occurrence of some pathogenic microorganisms in vegetable consumed on a daily basis by costa ricans. cryptosporidium sp. oocysts were found in 5.2% (4/80) of cilantro leaves, in 8.7% (7/80) of cilantro roots and 2.5% of lettuce samples. a 1.2% (1/80) incidence was found in other vegetables samples (carrot, cucumber, radish and tomatoe). oocysts of this parasite were absent in cabbage. giardia intestinalis was only detected in 5.2% (4/80) of cilantro leaves and in 2.5% (2/ ... | 1996 | 9429609 |
| short report: identification of b-cell epitopes in the serine-rich entamoeba histolytica protein. | the serine-rich entamoeba histolytica protein (srehp) has been shown to be a protective antigen in animal models of amebic liver abscess when delivered by either parenteral or oral routes of immunization, and antibodies to srehp can prevent amebic liver abscess in severe combined immunodeficient mice. to identify b cell epitopes of the srehp molecule that could serve as the basis for a peptide-based vaccine, we synthesized overlapping peptides spanning the amino acid sequence of srehp, and looke ... | 1997 | 9430535 |
| present characteristics of symptomatic amebiasis due to entamoeba histolytica in the east-southeast area of tokyo. | admitted medical records, from january 1988 to december 1995, of 28 symptomatic amebic patients who lived in the east-southeast area of tokyo were studied retrospectively, in order to find the present characteristics of symptomatic amebiasis due to entamoeba histolytica in this area. categorized by disease, there were 14 cases of colitis, 9 cases of liver abscess, 4 cases of colitis with liver abscess, and 1 case of liver abscess with brain abscess. patients consisted of 26 japanese males, 0 jap ... | 1997 | 9440441 |
| cloning and expression of the gene for the active ppi-dependent phosphofructokinase of entamoeba histolytica. | pyrophosphate-dependent phosphofructokinase (ppi-pfk) from entamoeba histolytica (hm-1) was purified from trophozoites. oligonucleotide probes based on partial amino acid sequence were used to clone and sequence the gene and the cdna of the enzyme. the molecular mass of the subunit was greater than, and the derived sequence significantly different from, that of the product of the ppi-pfk gene previously cloned from e. histolytica [huang, albach, chang, tripathi and kemp (1995) biochim. biophys. ... | 1998 | 9445396 |
| [the diagnosis and surgical treatment of intestinal amebiasis]. | ninety-one patients with intestinal amebiasis (ia) were studied. all had been long suffering from ia due to the fact that it had not been diagnosed in time. indications for emergency surgery were profuse hemorrhage, perforation of amebic ulcers, gangrene, and toxic dilatation of the large intestine. planned operations were made in pseudopolyposis, strictures of the large intestine. surgical treatment was performed along with specific therapy. seven patients died due to late diagnosis, ineffectiv ... | 1997 | 9446003 |
| mucosal immunogenicity of a holotoxin-like molecule containing the serine-rich entamoeba histolytica protein (srehp) fused to the a2 domain of cholera toxin. | one strategy for the induction of mucosal immune responses by oral immunization is to administer the antigen in conjunction with cholera toxin. cholera toxin consists of one a polypeptide (cta) which is noncovalently linked to five b subunits (ctb) via the a2 portion of the a subunit (cta2). coupling of antigens to the nontoxic b subunit of cholera toxin may improve the immunogenicity of antigens by targeting them to gm1 ganglioside on m cells and intestinal epithelial cells. here, we describe t ... | 1998 | 9453596 |
| pyogenic liver abscess in children: some observations in the espírito santo state, brazil. | pyogenic liver abscess in children is uncommon in developed countries and there are few reports about the disease in developing countries including brazil. as pyogenic liver abscesses in children are frequently diagnosed in vitória (e. santo state, brazil), the records of admissions at the children's hospital (hospital infantil n.s. da glória) were surveyed. sixty-five cases of pyogenic liver abscess were observed over a period of three years, from may 1991 through april 1994 (mean of admissions ... | 1997 | 9458960 |
| involvement of superoxide dismutase and pyruvate:ferredoxin oxidoreductase in mechanisms of metronidazole resistance in entamoeba histolytica. | metronidazole resistance has been induced in an axenic strain of entamoeba histolytica (hth-56:mutm) following continuous exposure to steadily increasing drug concentrations. the drug-resistant line is routinely maintained in normally lethal levels of metronidazole (10 microm). resistance to this concentration of drug was developed over 177 days. decreased pyruvate:ferredoxin oxidoreductase (pfor) activity in anaerobic organisms is one mechanism of metronidazole resistance but in entamoeba, pfor ... | 1997 | 9462435 |
| the neutral cysteine proteinase of entamoeba histolytica degrades igg and prevents its binding. | patients infected with entamoeba histolytica generate specific igg that does not prevent invasive amebiasis or recurrent infection. studies investigated whether the effectiveness of the human humoral response was limited by cleavage of igg by the extracellular neutral cysteine proteinase of e. histolytica trophozoites, one of the first amebic products to interact directly with components of host defenses. purified proteinase cleaved polyclonal human and monoclonal murine igg in a dose-dependent ... | 1998 | 9466550 |
| comparison of pcr, isoenzyme analysis, and antigen detection for diagnosis of entamoeba histolytica infection. | the diagnosis of amebiasis by microscopic identification of the parasite in stool is insensitive and unable to distinguish the invasive parasite entamoeba histolytica from the commensal parasite e. dispar. in this study, we have tested a pcr technique for the detection of e. histolytica and compared it with isoenzyme analysis and the techlab e. histolytica-specific antigen detection test. the nested-pcr test we used is based on amplification of the small subunit rrna gene of e. histolytica and e ... | 1998 | 9466756 |
| liver involvement in systemic infection. | the liver is heavily involved in the vast majority of systemic infections. pathophysiological mechanisms involved in hepatic involvement in generalized sepsis require further study, as does the importance of bacterial infection in the presence of cirrhosis. although parasitic involvement is theoretically dominated by plasmodium spp., in clinical practice entamoeba histolytica, schistosoma spp. and echinococcus spp. infections are far more important. hepatobiliary involvement is also a feature of ... | 1997 | 9471032 |
| [epidemiology of children's intestinal parasitism in the guadalquivir valley, spain]. | intestinal parasitism represents a public health problem that should be periodically assessed in each region. in the present paper, a study about prevalence of intestinal parasites, has been carried out in children from the natural region of the guadalquivir valley. | 1997 | 9477709 |
| isolation and molecular characterization of a surface-bound proteinase of entamoeba histolytica. | major pathogenic functions of entamoeba histolytica involved in destruction of host tissues are the degradation of extracellular matrix proteins mediated by secreted cysteine proteinases and contact-dependent killing of host cells via membrane-active factors. a soluble protein with an affinity for membranes was purified from amoebic extracts to apparent homogeneity. n-terminal sequencing and subsequent molecular cloning of the factor revealed that it is a member of the cysteine proteinase family ... | 1998 | 9484883 |
| prevalence of intestinal parasites in rural southern indians. | to determine the prevalence of intestinal protozoal and helminthic infection in a rural population. | 1998 | 9484973 |
| recombinant expression and biochemical characterization of an nadph:flavin oxidoreductase from entamoeba histolytica. | the gene encoding a putative nadph:flavin oxidoreductase of the protozoan parasite entamoeba histolytica (eh34) was recombinantly expressed in escherichia coli. the purified recombinant protein (receh34) has a molecular mass of about 35 kda upon sds/page analysis, exhibits a flavoprotein-like absorption spectrum and contains 1 mol of non-covalently bound fmn per mol of protein. receh34 reveals two different enzymic activities. it catalyses the nadph-dependent reduction of oxygen to hydrogen pero ... | 1998 | 9494088 |
| heterogeneity of dna content and expression of cell cycle genes in axenically growing entamoeba histolytica hm1:imss clone a. | the cell division cycle of entamoeba histolytica was studied using multi-parametric flow cytometry in asynchronous and partially synchronised cells. dynamic changes in the dna synthesis and dna content of axenically growing trophozoites were observed by using 5-bromo-2'-deoxyuridine (brdu) uptake and dna specific fluorochromes. it was observed that dna synthesis in these cells continues beyond the typical s-phase stop point when dna duplication is complete. asynchronously growing e. histolytica ... | 1997 | 9497028 |
| molecular and biochemical characterization of phosphoglucomutases from entamoeba histolytica and entamoeba dispar. | entamoeba histolytica and entamoeba dispar have only recently been defined as two separate species. e. histolytica, the pathogenic species, is the microorganism causing invasive intestinal amoebiasis and/or liver abscess, while the morphologically similar e. dispar is nonpathogenic and noninvasive. the gold standard for the distinction of the two species has been the isoenzyme electrophoresis of phosphoglucomutases (ec 5.4.2.2) and hexokinases (ec 2.7.1.1), but there had also been a controversy ... | 1997 | 9497037 |
| primary structure of entamoeba histolytica gamma-tubulin and localisation of amoebic microtubule organising centres. | 1997 | 9497056 | |
| [infection by intestinal protozoa and helminths in schoolchildren from riverside sectors, with different fecal contamination levels, of valdivia river, chile]. | during 1993, the prevalences of infection by intestinal protozoa and helminths (iph) in the riverside schoolchildren population of two sectors of valdivia river, with different levels of fecal contamination, were compared in relation to their contact with river water (swimming, bathing) and basic sanitation elements (bse) of their houses: feces and garbage disposal, and water supply. populations of children from sectors a (n = 418), with significatively greater (sg) total coliform most probable ... | 1997 | 9497533 |
| [human infection by intestinal protozoa and helminths in calbuco county, x region, chile, 1997]. | by the performance of parasitological examination of one fecal sample per individual, a total of 256 persons from a rural county in the x region (41 degrees 50 minutes south lat., 73 degrees 05 minutes west long.) were studied. the general rates of infection by intestinal parasite and/or commensal protozoa and helminths found were: giardia intestinalis 14.1%, entamoeba histolytica 11.7%, blastocystis hominis 36.0%, entamoeba coli 9.8%, endolimax nana 16.4%, iodamoeba buetschlii 1.2%, chilomastix ... | 1997 | 9497539 |
| entamoeba histolytica: liver invasion and abscess production by intraperitoneal inoculation of trophozoites in hamsters, mesocricetus auratus. | intraperitoneal inoculation of axenically cultured entamoeba histolytica trophozoites constitutes an easy to perform, highly reproducible procedure for inducing amebic liver abscesses in hamsters. efficiency in abscess production (95% of infected animals after 1 week) was similar to data reported using direct intrahepatic or intraportal inoculation. the morphological sequence of infection shows that amebas in the peritoneal cavity initially produce a large exudate constituted mainly of acute inf ... | 1998 | 9501845 |
| entamoeba histolytica and entamoeba dispar are distinct species; clinical, epidemiological and serological evidence. | the name of the causative organism of invasive amoebiasis, entamoeba histolytica, was first introduced in 1903, even though this intestinal amoeba had been recognised since 1875. the marked disparity between the number of infected individuals and those with invasive amoebiasis resulted in a number of explanatory hypotheses being proposed. although none of these were universally accepted, brumpt's concept of two morphologically identical species gained increasing acceptance 50-60 years later when ... | 1998 | 9504344 |
| expression and characterization of recombinant pyruvate phosphate dikinase from entamoeba histolytica. | the parasite entamoeba histolytica is an organism whose main energetic source comes from glycolysis. it has the singularity that several of its glycolytic enzymes use pyrophosphate as an alternative phosphate donor. thus, pyruvate phosphate dikinase (ppdk), an inorganic pyrophosphate (ppi)-dependent enzyme, substitutes pyruvate kinase present in humans. we previously cloned and sequenced the gene that codifies for ppdk in e. histolytica. we now report its expression in a bacterial system and its ... | 1998 | 9507062 |
| glycosidases in mucin-dwelling protozoans. | a range of protozoans were tested for the presence of glycosidases using p-nitrophenyl sugars as substrates. some of the organisms were mucin dwellers whereas others were blood borne parasites. it had been hypothesized that glycosidase production would be significantly higher in the mucin dwellers. the results obtained demonstrated that the urogenital protozoans tritrichomonas foetus and trichomonas vaginalis produced a vast range of glycosidases which included those required for mucin breakdown ... | 1997 | 9511996 |
| modeling of entamoeba histolytica ferredoxin. | the e. histolytica ferredoxin (ehfxd) is an iron-sulphur protein and is important in the control of e. histolytica because it donates an electron to and activates metronidazole (4) the most effective anti-amoebic drug. the knowledge of the three-dimensional structure of ehfxd can help to assist in rational design of anti-amebic drugs. homology modeling of ehfxd has been done by using the knowledge of crystal structure of homologous ferredoxin structures. it has been shown that ehfxd is more like ... | 1998 | 9514244 |
| regulation of expression of ribosomal protein l-21 genes of entamoeba histolytica and e. dispar is at the post-transcriptional level. | two genes, ehgle3 and ehg34, encoding the ribosomal protein l21 (rp-l21) were identified and characterized from entamoeba histolytica. their coding regions are highly conserved, but their flanking regions differ significantly. analogous genes (edgle3 and edg34) were characterized in e. dispar. the two rp-l21 copies are transcribed at similar levels in the two parasites. however, their relative binding to the polyribosomal complex during active translation is different. in e. histolytica, binding ... | 1998 | 9515695 |
| transcriptional analysis of the ehpgp1 promoter of entamoeba histolytica multidrug-resistant mutant. | we present here the cloning and characterization of the ehpgp1 multidrug resistance gene promoter isolated from the entamoeba histolytica drug-resistant mutant clone c2. the ehpgp1 promoter lacks the typical tata box and the transcriptional initiation sequences described for other e. histolytica promoters. the major transcription initiation site of the ehpgp1 gene was located at the atg start codon. the ehpgp1 core promoter located within the first 244 base pairs showed a higher chloramphenicol ... | 1998 | 9516421 |
| transcriptional analysis of the ehpgp5 promoter of entamoeba histolytica multidrug-resistant mutant. | we report here the cloning and transcriptional characterization of the ehpgp5 multidrug resistance gene promoter isolated from the drug-resistant clone c2 of entamoeba histolytica. the ehpgp5 promoter has the tata-like motif at -31 base pairs; transcription initiates three nucleotides upstream from the atg in trophozoites grown in 225 microm emetine (clone c2(225)), whereas in those grown without the drug (clone c2) a product with no open reading frame was detected. the promoter was active in tr ... | 1998 | 9516422 |
| cloning and heterologous expression of entamoeba histolytica adenylate kinase and uridylate/cytidylate kinase. | we have isolated two cdna clones encoding entamoeba histolytica nucleotide kinases, ehak and ehuk, expressed them in e. coli and performed functional studies of the recombinant enzymes. nucleotide sequence analysis showed that ehak and ehuk genes exhibited the features characteristic of e. histolytica genes, such as transcripts with relatively short 5' and 3' untranslated flanking regions containing the conserved e. histolytica transcription promoter elements located 5' to the initiation codon a ... | 1998 | 9524270 |
| [intestinal parasitic infections in serbia]. | to determine the public health significance of intestinal parasitism in serbia today, systematic parasitologic examination of 16 regions (kragujevac, luchani, zhagubica, bor, sjenica, novi pazar, valjevo, aleksandrovac, pirot, bosilegrad, ivanjica, golubac, uzhice, kladovo, negotin, beograd) in central serbia were carried out over the period 1984-1993. the study involved a total of 5981 schoolchildren (2887 f, 3094 m), 7-11 years old representing 10% of the total age-matched population (n = 58,2 ... | 1998 | 9525075 |
| entamoeba histolytica: solubilization and biochemical characterization of dolichol phosphate mannose synthase, an essential enzyme in glycoprotein biosynthesis. | sequential treatment of trophozoite membranes with the nonionic detergents brij 35 and igepal ca-630 released a soluble fraction that efficiently catalyzed the transfer of mannose from gdp-man into a mannolipid that was identified as dolichol phosphate mannose (dol-p-man) by several criteria. the transfer reaction occurred only in the presence of exogenously added dolichol monophosphate (dol-p). plots of enzyme velocity versus dol-p and gdp-man concentrations revealed sigmoidal and hyperbolic ki ... | 1998 | 9538865 |
| entamoeba infected orbital cysts as a late complication to orbital floor fractures. | an unusual late complication to an orbital floor fracture is presented. five years after trauma a now 22-year old man demonstrated an entamoeba infected cyst in the orbit. | 1998 | 9541452 |
| [an amebic liver abscess; early suspicion, late detection]. | two men aged 38 and 26 years developed symptoms including pain in the (upper) abdomen, malaise and fever 1.5-5 months after visiting the caribbean. it was only after repeated ultrasonography that liver abscesses were observed. adequate treatment was instituted and the patients recovered. the diagnosis of 'amoebic abscess of the liver' is usually based on the clinical presentation, the serological findings and characteristic observations at ultrasonography. however, if patients are seen at an ear ... | 1997 | 9542869 |
| [enteroparasitoses in food handlers of the public schools in uberlândia (minas gerais), brazil]. | a prospective study based on a parasitologic survey was carried out with a view toward controlling enteroparasitoses in food handlers who work in public primary schools in uberlândia, minas gerais, brazil. the study subjects were 264 individuals from 57 schools, from whom three fecal samples (c) were collected: c1 in september 1989, c2 in april 1990, and c3 in september 1990. the participants were predominantly female (259 women and 5 men) and ranged in age from 20 to 66 years. a total of 792 sa ... | 1997 | 9546081 |
| amebic liver abscess complicated with cardiac tamponade and mediastinal abscess. | amebic pericarditis is an extremely rare complication of liver abscess and an uncommon etiology of sterile pericardial effusion with cardiac tamponade. the association of mediastinal abscess in this clinical setting has not been reported in the literature. herein, we describe a case of amebic liver abscess complicated with mediastinal abscess and amebic pericarditis with cardiac tamponade. a 44-year-old man was admitted to our hospital because of shortness of breath for the previous 2 days. card ... | 1998 | 9549274 |
| entamoeba dispar: cultivation with sterilized crithidia fasciculata. | four isolates of entamoeba dispar identified by their hexokinase and phosphoglucomutase isoenzyme profile and by their failure to react with entamoeba histolytica-specific monoclonal antibody (4g6) could be grown in either diamond's bi-s-33 medium, newly developed bcsi-s (biosate cysteine starch iron-serum) medium, or casein-free yi-s medium in the presence of crithidia fasciculata (ref-1:prr) sterilized by heating 56 degrees c for 30 min and subsequent incubation with 1% hydrogen peroxide for 2 ... | 1998 | 9561776 |
| identification of significant variation in the composition of lipophosphoglycan-like molecules of e. histolytica and e. dispar. | the lipophosphoglycan-like (lpg-like) molecules of e. histolytica virulent strains are clearly distinct from those of the avirulent e. histolytica and e. dispar strains. abundant 'lpg' levels are apparently limited to virulent strains, while lipophosphopeptidoglycans ('lppg's) are common to both virulent and avirulent strains of e. histolytica and e. dispar. it is therefore conceivable that 'lppg' performs a function that is essential to survival within the host, while the 'lpg' performs a more ... | 1998 | 9561777 |
| molecular analysis of the gal/galnac adhesin of entamoeba histolytica. | attachment of entamoeba histolytica to colonic epithelium and a variety of other target cells is mediated by a galactose/n-acetyl d-galactosamine (gal/galnac) inhibitable adhesin. seven monoclonal antibodies specific for nonoverlapping epitopes of the 170 kda subunit have been shown to have distinct effects on adherence. four of these monoclonal antibodies inhibit or have no effect on amebic adherence while two others enhance amebic adherence. the epitopes recognized by these seven monoclonal an ... | 1998 | 9561778 |
| functional heterogeneity of colonic adenocarcinoma mucins for inhibition of entamoeba histolytica adherence to target cells. | mucins secreted from the gastrointestinal epithelium from the basis of the adherent mucus layer which is the host's first line of defense against invasion by entamoeba histolytica. galactose and n-acetyl-d-galactosamine residues of mucins specifically inhibit binding of the amebic 170 kda heavy subunit gal-lectin to target cells, an absolute prerequisite for pathogenesis. herein we characterized the secretory mucins isolated from the human colon and from three human colonic adenocarcinoma cell l ... | 1998 | 9561779 |
| the effects of entamoeba histolytica lysates on human colonic mucins. | detergent lysates of entamoeba histolytica trophozoites contained high levels of beta-n acetyl-d-glucosaminidase, beta-n acetyl-d-galactosaminidase and alpha-d-galactosidase activity, and lower but significant levels of five other glycosidases. although these activities should have been capable of largely degrading the oligosaccharide side-chains of human colonic mucin, in fact only about one third of high mw mucin was degraded in 72 h and trypsin alone produced a similar effect. there was no ev ... | 1998 | 9561780 |
| molecular changes in entamoeba histolytica in response to bacteria. | entamoeba histolytica, the protozoan parasite, is the causative agent of amoebiasis. the degree of virulence, as inferred from invasiveness, of potentially pathogenic strains may be regulated by both host and parasite factors that determine the gut environment. one such factor that plays an important role is the bacterial flora in the gut. previous studies have clearly shown that bacterial flora is an important determinant of virulence in e. histolytica. however, the exact nature of changes indu ... | 1998 | 9561781 |
| [prevalence of antibodies to entamoeba histolytica in the northern area of the province of huelva]. | 1998 | 9562953 | |
| differentiation of pathogenic and non-pathogenic entamoeba: has the question been answered? | pathogenic and non-pathogenic entamoeba have been separated into two distinct species. recently, the non-pathogenic e. dispar has been cultivated axenically. however, the genetic variability among different clones from the same strain, experimental production of hybrid clones which may differ from their parents, and the possibility of invasiveness of e. dispar, are some phenomena which may indicate that the last word on distinctiveness of the species has not yet been said. | 1998 | 9563222 |
| isolation of an entamoeba histolytica intracellular alkaline phospholipase a2. | the major hemolytic activity of entamoeba histolytica is located in a subcellular fraction called p30. its maximal effect is observed at ph 8.0 and 1 mm ca2+ and is due to a phospholipase a (pla). in the present study a membrane-associated phospholipase a2 was purified from p30 to homogeneity. p30 was fractionated with ethyl ether and the insoluble fraction was extracted with 1 m kcl. the kcl-soluble material was diluted ten times with 0.1 m tris-hcl (ph 9.5) and passed through a chromatofocusin ... | 1998 | 9569097 |
| control of ferredoxin and gal/galnac lectin gene expression in entamoeba histolytica by a cis-acting dna sequence. | the ferredoxin (fdx) and lectin (hgl5) promoters of entamoeba histolytica contain the dna sequence motif tattctatt (ure3). previously we showed that mutation of the ure3 motif in the hgl5 lectin promoter results in an increase in promoter reporter activity. mutation of this motif in the fdx promoter led to a 40-to-50% decrease in fdx promoter activity as measured by reporter gene activity and abundance of mrna. e. histolytica nuclear proteins exhibited sequence-specific binding to the ure3 motif ... | 1998 | 9573137 |
| longitudinal study of the antibody response to recombinant entamoeba histolytica antigens in patients with amebic liver abscess. | serology is a critical component in the diagnosis of amebic liver abscess. however, in areas endemic for amebiasis there is a high background level of seropositivity for amebiasis (owing to previous infection with entamoeba histolytica), which may complicate the interpretation of a positive serologic test result. recently, we reported that serologic tests based on recombinant e. histolytica antigens might offer improved diagnosis of current invasive amebiasis because they apparently differentiat ... | 1998 | 9574784 |
| entamoeba histolytica: collagen-induced ap-1 dna binding activity. | the interaction of entamoeba histolytica trophozoites with collagen induces the synthesis and release of electron-dense granules containing a collagenase activity that is an important factor in the pathogenicity of the parasite. the binding is thought to be mediated by an 'integrin-like' collagen receptor. in the signal transduction mechanisms activated by collagen, pp125fak and p42mapk are involved. using immunoprecipitation assays coupled to western blot analysis, we demonstrate here the colla ... | 1998 | 9580078 |
| nitazoxanide for the treatment of intestinal protozoan and helminthic infections in mexico. | a study to evaluate the efficacy and safety of nitazoxanide as a single agent for the treatment of a broad spectrum of mixed parasitic infections, both protozoa and helminths, was conducted at a primary school in san pedro tolimán, querétaro, mexico. three faecal samples from 1824 adults and children were screened for the presence of oocysts, cysts, trophozoites, eggs or larvae of intestinal protozoa or helminths. two hundred and forty-six adults and children infected with at least one protozoan ... | 1997 | 9580117 |
| the bactericidal activity of blood platelets in patients infested with entamoeba histolytica/entamoeba dispar. | blood platelets participate actively in organism defensive reactions and particularity in antiparasitic immunity. platelets stimulation can be the result of contact with a parasite, the presence of immunoglobulins, complement and lymphokines. the aim of the study was to evaluate the blood platelets bactericidal activity in the course of amoebiasis. the examination was carried out in the group of 22 patients with e. histolytica/e. dispar, diagnosed on the basis of cyst forms presence in faeces. t ... | 1997 | 9581473 |
| case of the season. amebic abscess (entamoeba histolytica) of the liver. | 1998 | 9583105 | |
| slaying the hydra all at once or head by head? | 1998 | 9585195 | |
| entamoeba histolytica induces host cell death in amebic liver abscess by a non-fas-dependent, non-tumor necrosis factor alpha-dependent pathway of apoptosis. | amebic liver abscess is characterized by extensive areas of dead hepatocytes that form cavities surrounded by a thin rim of inflammatory cells and few entamoeba histolytica trophozoites. e. histolytica produces pore-forming proteins and proteinases, but how trophozoites actually kill host cells has been unclear. here, we report that e. histolytica induces apoptosis in both inflammatory cells and hepatocytes in a severe combined immunodeficient (scid) mouse model of amebic liver abscess. by study ... | 1998 | 9596776 |
| the small gtp-binding protein racg regulates uroid formation in the protozoan parasite entamoeba histolytica. | entamoeba histolytica is a protozoan parasite that invades human intestine leading to ulceration and destruction of tissue. amoebic movement and phagocytosis of human cells is accompanied by characteristic changes in cell morphology. amoebae become polarized, developing a frontal pseudopod and a well-defined rear zone of membrane accumulation designated the uroid. in motile eukaryotic cells, a phenomenon that contributes to movement is the capping of receptors at the cell surface. during the cap ... | 1998 | 9601102 |
| entamoeba histolytica hm1:imss: hemoglobin-degrading neutral cysteine proteases. | entamoeba histolytica hmi:imss trophozoites were able to utilize human hemoglobin but not hemin as a sole iron source to grow in vitro. proteases from crude extracts of e. histolytica degraded human, porcine, and bovine hemoglobins at ph 7.0. these proteolytic activities were found by electrophoresis in sds-polyacrylamide gels copolymerized with hemoglobin, with apparent molecular weights of 116, 82, and 21 kda, the 82-kda protein being the most active protease against this substrate. the protea ... | 1998 | 9603491 |
| chromatin organization during the nuclear division stages of live entamoeba histolytica trophozoites. | 1998 | 9603497 | |
| proteinase activity & virulence of entamoeba histolytica on passage through hamster liver. | this study was undertaken to determine the enzymatic differences in the process of increasing the degree of virulence in e. histolytica successively passaged in hamster liver. substrate gel electrophoresis was used to compare proteinase banding patterns under reducing conditions from whole cell lysates of one axenic e. histolytica (strain hm1:imss) and five xenic isolates of the same strain of e. histolytica passaged five times through hamster liver. trophozoites successively passaged in hamster ... | 1998 | 9604544 |
| virulence and functions of myosin ii are inhibited by overexpression of light meromyosin in entamoeba histolytica. | several changes in cell morphology take place during the capping of surface receptors in entamoeba histolytica. the amoebae develop the uroid, an appendage formed by membrane invaginations, which accumulates ligand-receptor complexes resulting from the capping process. membrane shedding is particularly active in the uroid region and leads to the elimination of accumulated ligands. this appendage has been postulated to participate in parasitic defense mechanisms against the host immune response, ... | 1998 | 9614192 |
| a survey of amoebic infection in the wonji area of central ethiopia. | an epidemiological survey to characterize entamoeba histolytica/e dispar isolates from 123 human subjects was carried out in the wonji area of central ethiopia, where an increased incidence of amoebic infection has been reported. in a randomized, coproparasitological study, 93 (75.6%) of the subjects were found positive for at least one species of intestinal parasite: 14 (15.1%) harboured only one species and 79 (84.9%) were infected with at least two species. in-vitro culture in robinson's medi ... | 1998 | 9625913 |
| entamoeba histolytica contains a beta 1 integrin-like molecule similar to fibronectin receptors from eukaryotic cells. | entamoeba histolytica trophozoites do interact with extracellular matrix components in order to invade and finally destroy tissue. an important step in this interaction involves the binding of a 140-kda membrane protein that binds to fibronectin. the similarity of this amoebic receptor to fibronectin receptors from higher eukaryotic cells was defined by indirect immunofluorescence, western blot and immunohistochemistry, using polyclonal monospecific antibodies raised against the amoebic protein. ... | 1998 | 9627997 |
| [recommendations for treatment of amebiasis. german society of pediatric infectiology e.v. (dgpi), "parasitology" working group]. | 1998 | 9629551 | |
| characterization and quantitation of parasite species in the effluents of the berisso main sewage channel, buenos aires, argentina. | outbreaks of disease can be caused by pathogenic intestinal parasites in drinking water. la plata, the capital of the province of buenos aires, argentina, is located on the la plata river; a principal tributary receiving the raw sewage from the city's 500,000 inhabitants via the berisso main septic channel at an estimated volume of 108,390 m3/day (4516.3m3/h). to determine the parasite-contamination level of the la plata river, we obtained 18 sewage effluents from the berisso main septic channel ... | 1997 | 9638888 |
| [vegetables for human consumption as probable source of toxocara sp. infection in man]. | although toxocara canis life cycle is known, other possible mechanisms dynamically involved in its transmission to man are still ignored. the object of the present investigation was to search the occurrence of toxocara sp. eggs in vegetables which humans consume. five hundred and thirty six vegetables from a supply distribution center in mexico city (distrito federal) were examined. those included 212 carrots, 76 potatoes, 31 radishes, 22 mushrooms, 27 lettuces, 20 sweet potatoes and 66 bundles ... | 1997 | 9640678 |
| antisense inhibition of expression of cysteine proteinases does not affect entamoeba histolytica cytopathic or haemolytic activity but inhibits phagocytosis. | inhibition of most of the expression of the cysteine proteinases of entamoeba histolytica strain hm-1:imss was successfully performed by transcription of ehcp5 antisense rna using the promoter of ehg34, which encodes a l21 ribosomal protein of e. histolytica. we have generated a stable transfectant in which the overall level of cysteine proteinase activity is strongly reduced ( 90%). this transfectant has a normal growth rate in diamond's tyi-s-33 medium, a cytopathic and haemolytic activity sim ... | 1998 | 9643545 |
| intestinal parasite infections after extended use of chloroquine or primaquine for malaria prevention. | comparative results of baseline and endpoint screening for intestinal parasites are reported from javanese men enrolled in a year-long, placebo-controlled malaria prophylaxis trial in irian jaya. the objective was to detect nontarget qualitative changes that may have resulted from prolonged chloroquine (300 mg base weekly) or primaquine (0.5 mg base/kg daily) prophylaxis. fresh fecal specimens were examined (blinded trial) for parasites and ova using a modified kato-katz thick smear method. more ... | 1998 | 9645872 |
| axenic cultivation of trichomonas vaginalis in a serum-free medium. | mammalian serum or bovine serum albumin are essential for trichomonas vaginalis cultivated under axenic conditions. unfortunately, these components inhibit several biological properties of these parasites. pacsr is a serum replacement, free of bovine serum albumin. used for axenic cultivation of entamoeba histolytica. we show that pacsr is also useful for axenic cultivation of t. vaginalis. tubes containing 5.5 ml pehp, or tyi basal media, plus 8% pacsr (v/v), were inoculated with 10(3) trichomo ... | 1998 | 9645876 |
| evaluation of intestinal protozoan morphology in human fecal specimens preserved in ecofix: comparison of wheatley's trichrome stain and ecostain. | as a result of disposal problems related to the use of mercury compounds, many laboratories have switched from mercuric chloride-based schaudinn's and polyvinyl alcohol (pva) stool preservatives to other, non-mercury-based preservatives. a comparison of organism recoveries and morphologies of the intestinal protozoa was undertaken with pva containing the ecofix zinc-based schaudinn's preservative (meridian diagnostics, inc.); both wheatley's modification of gomori's trichrome stain (wt) and ecos ... | 1998 | 9650947 |
| role of neutrophils in innate resistance to entamoeba histolytica liver infection in mice. | in order to define the role of neutrophils in the innate resistance to entamoeba histolytica liver infection in mice, we examined the pattern of liver lesion induced by direct injection of e. histolytica trophzoites in normal mice and in neutrophil-depleted mice. a variety of histological lesions were found, the extent of liver damage was considerably higher in the neutrophil-depleted mice. livers from neutrophil-depleted mice displayed areas of liquefactive (lytic) necrosis containing a large n ... | 1998 | 9651927 |
| cloning and expression of the entamoeba histolytica erd2 gene. | 1998 | 9657339 | |
| synergy between entamoeba histolytica and escherichia coli in the induction of cytokine gene expression in human colon epithelial cells. | entamoeba histolytica induces the expression and secretion of interleukin 8 (il-8) by cultured colon epithelial cells. we assessed the array of cytokine genes expressed by human colon epithelial cells in response to co-culture with e. histolytica trophozoites and tested the hypothesis that enteric bacteria may alter the e. histolytica-induced expression of such genes. ht-29 colon epithelial cells were co-cultured with e. histolytica trophozoites in the presence or absence of escherichia coli. cy ... | 1998 | 9660143 |
| the human monocyte locomotion-inhibitory factor produced by entamoeba histolytica does not inhibit the locomotion of human eosinophils. | 1998 | 9660147 | |
| entamoeba dispar: ultrastructure, surface properties and cytopathic effect. | the cytological features of entamoeba dispar, recently recognized by biochemical and molecular biology criteria as a distinct species, were compared to those of entamoeba histolytica when cultured under axenic conditions, living trophozoites of e. dispar strain saw 76orr clone a were more elongated in form, had a single frontal pseudopodium, and showed a noticeable uroid. in sections of e. dispar trophozoites stained with toluidine blue, characteristic areas of cytoplasmic metachromasia were see ... | 1998 | 9669863 |
| ecto-nucleotide triphosphatase activity in pathogenic and non-pathogenic entamoeba: protection from the cytotoxic effects of extracellular atp. | the nucleotide triphosphatase (ntpase) activity of entamoeba species and of entamoeba histolytica strains, was compared. in all cases, with the exception of entamoeba moshkovskii, the enzyme was activated by ca2+ and not by mg2+ and preferentially hydrolysed utp with decreasing activity for atp and gtp. the ntpase activity was associated with both the intracellular and the plasma membrane sulphonylbenzoyl-adenosine (fsba) of trophozoites in which the atp-site was facing externally, as shown by f ... | 1997 | 9670549 |