Publications

the cysteine-rich region of the entamoeba histolytica adherence lectin (170-kilodalton subunit) is sufficient for high-affinity gal/galnac-specific binding in vitro.	adherence of entamoeba histolytica trophozoites to colonic mucin, epithelium, and other target cells is mediated by the amebic gal/galnac lectin. we constructed in vitro expression vectors containing full-length (residues 1 to 1280), cysteine-poor (1 to 353 and 1 to 480), and cysteine-rich (356 to 1143 and 480 to 900) fragments of the gene encoding the heavy subunit of the adherence lectin, hgl2. in vitro transcription followed by translation using a nuclease-treated rabbit reticulocyte lysate s ...	1999	10417146
entamoeba histolytica : a novel cysteine protease and an adhesin form the 112 kda surface protein.	here, we present evidence that a cysteine protease (ehcp112) and a protein with an adherence domain (ehadh112) form the entamoeba histolytica 112 kda adhesin. immunoelectron microscopy and immunofluorescence assays using monoclonal antibodies (mabadh) revealed that, during phagocytosis, the adhesin is translocated from the plasma membrane to phagocytic vacuoles. mabadh inhibited 54% adherence, 41% phagocytosis, and 35% and 62% destruction of mdck cell monolayers by live trophozoites and their ex ...	1999	10417646
antimicrobial and cytolytic polypeptides of amoeboid protozoa--effector molecules of primitive phagocytes.	amoebae are primitive, actively phagocytosing eukaryotic cells, many of which use bacteria as a major nutrient source. one may suppose that amoebae possess an array of potent antimicrobial molecules acting in synergy to combat bacterial growth inside their phagosomes. lysosome-like granular vesicles of entamoeba histolytica contain a family of 77-residue peptides with a compact alpha-helical, disulfide-bonded fold. these polypeptides, named amoebapores, exhibit antibacterial and cytolytic activi ...	1999	10426421
dna sequences corresponding to the ariel gene family of entamoeba histolytica are not present in e. dispar.	for the identification of quantitative genetic differences between pathogenic entamoeba histolytica and the closely related but nonpathogenic species e. dispar, a set of 68 independent probes that had previously been isolated from an e. histolytica cdna library were hybridized to total genomic dna of both amoeba species. besides ehcp5, the sequence that codes for cysteine proteinase 5 and has recently been shown to be missing in e. dispar, only one of the probes exclusively reacted with e. histo ...	1999	10431751
[invasive amebiasis at an institution for the mentally retarded in hyogo prefecture].	an outbreak of amebiasis caused by entamoeba histolytica occurred at an institution for mentally retarded persons in hyogo prefecture. twelve out of a total of 49 admitted persons exhibited e. histolytica cysts in their stool, and 13 including persons in whom no cysts had been detected showed positive serological reactions for e. histolytica infection. however, neither the cyst nor the antibody against the organism was detected in the staff members of the institution. indirect fluorescence antib ...	1999	10442047
asymptomatic amebic colitis in a homosexual man.	we describe case of a 75-yr-old japanese homosexual man who was diagnosed as having amebic colitis. the present case is unique in that invasive amebiasis has occurred in a homosexual man, because entamoeba histolytica in homosexual patients is considered to be a nonpathogenic and commensal organism in western countries, and that the patient has not complained of any gastrointestinal symptoms associated with minute colonic lesion of an isolated cecal ulcer. this report indicates that the absence ...	1999	10445573
immunochromatographic strip-based detection of entamoeba histolytica-e. dispar and giardia lamblia coproantigen.	biosite triage was 68.3% sensitive and 100% specific for the detection of entamoeba histolytica-e. dispar (n = 71) compared to alexon-trend's prospect test (reference standard) using fresh-frozen stool. neither test is able to distinguish e. histolytica from e. dispar. triage was 83.3% sensitive and 100% specific compared to microscopy (formalin-ether concentrates and permanent stains) for the detection of giardia lamblia.	1999	10449494
analysis by enzyme-linked immunosorbent assay and pcr of human liver abscess aspirates from patients in china for entamoeba histolytica.	aspirates of liver abscesses were analyzed for entamoeba histolytica. pcr detected a gene encoding a 30-kda protein in all samples but detected the ribosomal dna gene in only 14 (33.3%) samples. enzyme-linked immunosorbent assay detected antigen in 41 (97.6%) samples. pcr analysis of a strain-specific antigen (ssg) revealed that abscesses were caused by various strains.	1999	10449500
intestinal amoebiasis, giardiasis and geohelminthiases: their association with other intestinal parasites and reported intestinal symptoms.	in order to determine reported signs and symptoms that may predict an intestinal parasitic infection, 241 schoolchildren in western côte d'ivoire were interviewed with a simple questionnaire and their stool specimens were examined over several consecutive days. special emphasis was placed on (i) assessing infections by entamoeba histolytica/e. dispar, giardia duodenalis and by intestinal worms, (ii) looking for associations between these parasites, and (iii) looking for associations between thes ...	1999	10450435
virulence factors of entamoeba histolytica.	recent studies have increased our knowledge of entamoeba histolytica cell biology and gene regulation. in the ameba, dominant-negative mutations in the gal/galnac lectin affect adhesion and cytolysis, whereas mutations in meromyosin affect cytoskeletal function. studying these mutant proteins has improved our understanding of the role of these proteins in e. histolytica virulence. the characterization of the cp5 cysteine protease and the induction of apoptosis in host target cells has led to a b ...	1999	10458982
common presentations of amebic liver abscess.	the most common extraintestinal manifestation of entamoeba histolytica, the agent of amebiasis, is a hepatic abscess. this infection is common throughout the world and can be associated with life-threatening consequences. given the often nonspecific nature of the complaints related to an amebic abscess, a retrospective review of patients with confirmed disease was done to recognize the most common patterns of presentation.	1999	10459092
gtpases in protozoan parasites: tools for cell biology and chemotherapy.	small g proteins belong to a superfamily of gtpases related to the protooncogene ras, and function as master control elements for a range of cellular functions. this ability is related to their low rate of substrate turnover; gtpases catalyse the conversion of gtp to gdp, but with a rate in the order of one substrate per second, orders of magnitude slower than 'good' enzyme catalysis, but placing the reaction into the temporal frame of many cellular processes including signal transduction, cytos ...	1999	10461165
keto-acid oxidoreductases in the anaerobic protozoa.	in anaerobes, decarboxylation of pyruvate is executed by the enzyme pyruvate:ferredoxin oxidoreductase, which donates electrons to ferredoxin. the pyruvate:ferredoxin oxidoreductase and its homologues utilise many alternative substrates in bacterial anaerobes. the pyruvate:ferredoxin oxidoreductase from anaerobic protozoa, such as giardia duodenalis, trichomonas vaginalis, and entamoeba histolytica have retained this diversity in usage of alternative keto acids for energy production utilising a ...	1999	10461388
case studies in international travelers.	family physicians should be alert for unusual diseases in patients who are returning from foreign travel. malaria is a potentially fatal disease that can be acquired by travelers to certain areas of the world, primarily developing nations. transmitted through the bite of the anopheles mosquito, malaria usually presents with fever and a vague systemic illness. the disease is diagnosed by demonstration of plasmodium organisms on a specially prepared blood film. travelers can also acquire amebic in ...	1999	10465222
co-agglutination test for the detection of circulating antigen in amebic liver abscess.	we report here a simple and economical slide agglutination test, the co-agglutination (co-a) test, for the detection of circulating amebic antigen in sera for the diagnosis of amebic liver abscess. fifty serum specimens from cases of amebic liver abscess, 25 from other individuals with parasitic and miscellaneous infections, and 25 from healthy controls were tested for the presence of serum antigen by the co-a test. forty-five (90%) amebic liver abscess sera were found to be amebic-antigen posit ...	1999	10466984
detection by hplc of a trypanothione synthetase activity in vitro from entamoeba histolytica.	we have previously demonstrated the presence of glutathione-spermidine (gsp) and trypanothione [t(sh)(2)] from entamoeba histolytica trophozoites, on the basis of results obtained with acid extracts purified by florisil and deae-cellulose, derivatized with the fluorescent reagent monobromobimane and separated by hplc. gsp was originally found in escherichia coli and later in trypanosomatids such as trypanosoma cruzi, t. brucei, t. congolense and the insect trypanosomatid crithidia fasciculata, a ...	1999	10467117
entamoeba histolytica: a eukaryote with trypanothione metabolism instead of glutathione metabolism.	entamoeba histolytica is a human pathogen that lacks the capacity to synthesize glutathione but can incorporate it, from the growth media or presumably from the human host, to form trypanothione [n(1), n(8)-bis(glutathionyl)-spermidine conjugate]. this novel thiol compound has previously been found in trypanosomatids, as has its precursor glutathionyl-spermidine, which was originally detected in escherichia coli. previously we showed the presence of these two thiol compounds in extracts from cul ...	1999	10467118
metronidazole resistance in the protozoan parasite entamoeba histolytica is associated with increased expression of iron-containing superoxide dismutase and peroxiredoxin and decreased expression of ferredoxin 1 and flavin reductase.	to obtain insight into the mechanism of metronidazole resistance in the protozoan parasite entamoeba histolytica, amoeba trophozoites were selected in vitro by stepwise exposures to increasing amounts of metronidazole, starting with sublethal doses of 4 microm. subsequently, amoebae made resistant were able to continuously multiply in the presence of a 40 microm concentration of the drug. in contrast to mechanisms of metronidazole resistance in other protozoan parasites, resistant amoebae did no ...	1999	10473552
sesquiterpene lactones from neurolaena oaxacana	twelve sesquiterpene lactones, two new (1 and 2) and 10 known neurolenin-type germacranolides and furanoheliangolides (3-12) were isolated from neurolaena oaxacana, and their structures were elucidated by nmr and gc-ms analysis. the chemotaxonomic importance of these findings is discussed. as n. lobata is used against dysenteries, neurolenin b (4) and a mixture of the neurolenins c (5) and d (6) were tested against entamoeba histolytica and giardia intestinalis.	1999	10479310
[prevalence of intestinal parasitic infections in nursery schools from ciego de avila province, cuba. 1989-1993].	the prevalence of intestinal parasitsm in nursery schools from ciego de avila province was annually avaluated during 1989-1993. the percentage of infected children ranged from 16.6% to 31.6%. an increase of frequence of infection was observed from 1991. protozoa were more predominant than helminths. in the whole five-year period studied giardia intestinalis had a higher prevalence (19.6%) followed by entamoeba histolytica (3.0%). the nematode most frequently found was trichuris trichiura (0.5%).	1999	10488590
[seasonal variation of intestinal protozoa infections in outpatients of the north section of santiago, chile. 1995-1996].	formalin preserved fecal samples from 6,058 and 5,863 outpatients were examined for intestinal parasites during 1995 and 1996 respectively. prevalence rates of infections by intestinal protozoa in both years were similar. by age group (0-9, 10-19 and > 20 years old) blastocystis hominis was observed in 18.6-19.3, 37.0-31.1 and 25.3-25.4% in 1995-1996 respectively. prevalence of giardia intestinalis infections decreased from 16.6-17.4% in the 0-9 year-old children group to 4.1-4.5% in patients ov ...	1999	10488591
the effect of formalin fixation on the polymerase chain reaction characterization of entamoeba histolytica.	formalin fixation is the most common storage, transportation and preservation method for stool samples. however, fixation dramatically reduces our ability to extract from stool samples dna that is a suitable template for polymerase chain reaction (pcr)-based diagnostic tests. in this study we evaluated the effects of formalin concentration and of the time stored in fixative on the success of pcr amplification. we found that the deleterious effects of formalin are both time and concentration depe ...	1999	10492774
hla characterization in adult asymptomatic cyst passers of entamoeba histolytica/e. dispar.	the present work aimed at studying the possible association of hla antigens with entamoeba histolytica/e. dispar asymptomatic infection in a mexican mestizo population. a case-control design was selected for evaluation of the role of genetic markers in parasite infection. for this purpose the hla-a, hla-b, and hla-dr profiles of a population of asymptomatic e. histolytica/e. dispar adult cyst passers (cases) and a corresponding nonparasitized adult group (controls) followed for 12 months were id ...	1999	10494810
comparative modeling of amoebapores and granulysin based on the nk-lysin structure-structural and functional implications.	amoebapores, the pore-forming polypeptides of the protozoan parasite entamoeba histolytica, and effector proteins of porcine and human lymphocytes, namely nk-lysin and granulysin, reveal a substantial sequence similarity despite their enormous evolutionary distance. moreover, all these polypeptides display antibacterial activity and are in higher concentrations cytolytic to eukaryotic cells. the recently solved nmr structure of nk-lysin enabled us to build the three dimensional structures of amo ...	1999	10494853
growth stimulation by serum in entamoeba histolytica is associated with protein tyrosine dephosphorylation.	very little protein tyrosine phosphorylation was observed in growing (exponential-phase) entamoeba histolytica cells by immunoblotting and quantitative immunofluorescence. after 1 h of serum deprivation, two proteins (42 and 38 kda in sds-page) were tyrosine phosphorylated and two more proteins (96 and 63 kda) also showed tyrosine phosphorylation when examined after 4 h of serum deprivation. intense enhancements of anti-phosphotyrosine immunofluorescence levels were observed during this period o ...	1999	10499274
[cross-sectional study of intestinal parasites and chagas' disease in the municipality of novo airão, state of amazonas, brazil].	a cross-sectional study was performed on the residents of one in every ten households in the town of novo airão, in the northern meso-region of the state of amazonas, 250 kilometers from manaus by riverboat. a family cluster sample of 89 dwellings was studied. a stool sample was requested from each of the inhabitants for examination using the lutz sedimentation and baermann-moraes-coutinho techniques, and blood was taken by venous puncture for trypanosoma cruzi elisa antibody testing and immunof ...	1999	10502145
in vivo nanoimaging and ultrastructure of entamoeba histolytica by using atomic force microscopy.		1999	10502472
entamoeba histolytica: identification and properties of membrane-bound and soluble alpha-glucosidases.		1999	10502475
mucoid presentation of acute enterocolitis in children: a hospital-based case-control study.	a hospital-based case-control study was carried out to clarify the characteristics of mucoid presentation of acute enterocolitis in children. one hundred sixty-eight cases of acute mucoid enterocolitis (study population) were compared with 200 cases of watery diarrhoea and 118 cases of blood dysentery (control groups) on the basis of clinical characteristics and findings on stool examination. study and control groups were comparable with respect to age, body weight and nutritional status. there ...	1999	10503679
entamoeba histolytica outbreaks in institutions for the mentally retarded.		1999	10508000
secondary structure of a calcium binding protein (cabp) from entamoeba histolytica.	a calcium binding protein from entamoeba histolytica, (ehcabp, m(r) approximately 15 kda) is the causative agent for amoebiosis and has a very low sequence homology (approximately 30%) with other known cabps. almost complete sequence specific resonance assignments for (1)h, (13)c and (15)n spins in ehcabp were obtained using double and triple resonance nmr experiments. qualitative interpretation of the nuclear overhauser enhancements, chemical shift indices and of hydrogen exchange rates threw v ...	1999	10508916
entamoeba histolytica lacks trypanothione metabolism.	entamoeba histolytica lacks glutathione reductase activity and the ability to synthesise glutathione de novo. however, a recent report suggested that exogenous glutathione can be taken up and conjugated to spermidine to form trypanothione, a metabolite found so far only in trypanosomatids. given the therapeutic implications of this observation, we have carefully analysed e. histolytica for evidence of trypanothione metabolism. using a sensitive fluorescence-based hplc detection system we could c ...	1999	10514081
gastrointestinal parasitic infection, anthropometrics, nutritional status, and physical work capacity in colombian boys.	this article tests the hypothesis that the presence of gastrointestinal parasites in colombian boys is negatively associated with anthropometric characteristics, physical work capacity, blood hemoglobin (hb) levels, and nutritional status. anthropometric, hb, &vdot;o(2) max, and parasite load data were collected on 1,016 boys in cali, colombia. the boys were classified as lower socioeconomic class (sec) from either urban or rural environments, and upper sec from an urban environment. sixty-three ...	1999	11533992
amebiasis: clinical implications of the recognition of entamoeba dispar.	entamoeba histolytica was recently reclassified to recognize the existence of two genetically distinct but morphologically indistinguishable species: e. histolytica, the protozoan parasite that causes amebic dysentery and liver abscess, and entamoeba dispar, a nonpathogenic intestinal parasite. acceptance of this redefinition has dramatically changed both our understanding of the true epidemiology of e. histolytica and the optimal methods for diagnosing amebiasis. molecular-based diagnostic test ...	1999	11095821
comparative study of the efficacy and tolerability of secnidazole suspension (single dose) and tinidazole suspension (two days dosage) in the treatment of amebiasis in children.	amebiasis caused by entamoeba histolytica may be considered the most aggressive parasitic disease affecting human intestine, causing acute amoebic colitis and extra-intestinal diseases of high morbidity and mortality. 5-nitroimidazoles are the drugs of choice. in this multicenter, open and random clinical trial, the efficacy and tolerability of secnidazole suspension in a single oral dose of 1ml/kg was compared with 0.5ml/kg doses of tinidazole suspension given for 2 consecutive days to 303 enta ...	1999	11098194
analysis of cdna expressed sequence tags from entamoeba histolytica: identification of two highly abundant polyadenylated transcripts with no overt open reading frames.	upon analysis of 304 expressed sequence tags derived from the protozoan parasite entamoeba histolytica, a number of novel protein encoding amoeba sequences were isolated. in addition, two unrelated, abundantly expressed transcripts were identified, and designated, ehapt1 and ehapt2. although these transcripts do not contain any overt open reading frame, both are polyadenylated and together represent about 19% of total polya+-rna(11.6% for ehapt1 and 7.5% for ehapt2), thus being the most highly e ...	1999	10724519
new insights into the role of the cytoskeleton in phagocytosis of entamoeba histolytica.	entamoeba histolytica, a human parasite, crosses the natural barriers of the intestine and, in turn, spreads into the deeper organs, resulting in amoebiasis. the motility of the parasite and its ability to lyse or phagocytose human cells facilitates passage of the amoeba through the intestinal epithelium. little is known about the uptake of material by this parasite; nevertheless, the cytoskeleton is believed to play a role in phagocytosis. myosin ib, an actin-binding protein, localizes to the p ...	1999	11207552
physiology and molecular genetics of multidrug resistance in entamoeba histolytica.	entamoeba histolytica presents the evolutionarily conserved multidrug-resistance (mdr) phenotype, discovered in mammalian cells. mdr cells overexpress the membrane p-glycoprotein, which excludes unrelated drugs from the cytoplasm. e. histolytica mutants exhibit cross-resistance to unrelated drugs, which are pumped out from the cytoplasm. in drug-resistant trophozoites, the constitutively expressed ehpg1 gene appears to be up-regulated by a c/ebp-like factor and a multiprotein complex that were n ...	1999	11504490
role of dna probes in characterization of pathogenic and non-pathogenic e. histolytica.	various tests have been described to differentiate the pathogenic and non-pathogenic types of e. histolytica. recently dna hybridization has been described to differentiate between the two subtypes. using common hmc probe the presence of e. histolytica in stool was confirmed. then on the basis of hybridization with dna probe p 145 (pathogenic) and b 133 (non-pathogenic) e. histolytica was characterized as being pathogenic and non pathogenic respectively. out of 137 patients studied 88 were sympt ...	1998	11229277
trendys in biochemistry-98.		1998	10515725
ribosomal dna fragments enhance the stability of transfected dna in entamoeba histolytica.	genetic manipulation of entamoeba histolytica is limited by the inability to express foreign genes at high levels. we tested whether sequences from the e. histolytica rdna episome, present in 200 copies per cell, could act to stabilize the episomal transfection vector ptcv1. ligation of the rdna transcription unit, or sequences downstream of the rdna transcription unit, increased ptcv1 copy number and stability and conferred additional zones of dna replication. sequences upstream of the rdna tra ...	1998	9864856
69-year-old man with fever, diarrhea, and abdominal pain.		1998	9868422
application of lactophenol cotton blue for identification and preservation of intestinal parasites in faecal wet mounts.	wet mounting is the simplest and easiest technique for the examination of faeces. routinely employed wet mounts in most of the laboratories include saline, iodine and buffered methylene blue. lactophenol cotton blue [lcb] staining--mounting medium is commonly used for microscopic identification of fungi. lcb and its modifications were tested as staining mounting medium on parasite positive faecal samples [both fresh as well as formalin fixed] to stain and demonstrate morphology and to preserve p ...	1998	9670627
role of serum in regulating the entamoeba histolytica cell cycle: a flowcytometric analysis.	to identify stage-specific molecules that might be important in pathogenicity, we focused on synchronizing entamoeba histolytica hm1:1mss axenic cultures by serum deprivation. by growing trophozoites in medium containing 2% serum for 16 h and then replacing with complete medium, we found that most of the trophozoites were in the g0/g1 phase of the cell cycle. subsequently, the distribution of trophozoites in g0/g1, s and g2/m phases was studied for up to 24 h and it was observed that after 8 h, ...	1998	9797069
heat shock protein 70 family: multiple sequence comparisons, function, and evolution.	the heat shock protein 70 kda sequences (hsp70) are of great importance as molecular chaperones in protein folding and transport. they are abundant under conditions of cellular stress. they are highly conserved in all domains of life: archaea, eubacteria, eukaryotes, and organelles (mitochondria, chloroplasts). a multiple alignment of a large collection of these sequences was obtained employing our symmetric-iterative iteralign program (brocchieri and karlin 1998). assessments of conservation ar ...	1998	9797407
secretory immune response in patients with intestinal amoebiasis.	the secretory immune response in saliva from intestinal amoebiasis patients against antigens obtained from entamoeba histolytica membranes was studied. western blot analysis indicated that patient saliva contains secretory iga antibodies against antigens with molecular masses ranging from 170 to 24 kda, some of which were also recognized by saliva from healthy subjects. however, antigens of 170, 125, 46 and 37 kda are recognized more frequently (> 90%) by the secretory iga from patients with int ...	1998	9797512
molecular characterization of an exceptionally acidic lysozyme-like protein from the protozoon entamoeba histolytica.	the protozoan parasite entamoeba histolytica contains a second antibacterial protein with lysozyme-like properties. the newly recognized bacteriolytic protein was purified from extracts of amoebic trophozoites to allow amino-terminal sequencing. subsequent molecular cloning revealed that it is an isoform of the amoeba lysozyme described previously but also demonstrated a substantial sequence divergence of the two forms. as lysozymes typically are basic proteins, the novel amoebic protein differs ...	1998	9804191
entamoeba histolytica: identification of functional gs and gi proteins as possible signal transduction elements in the interaction of trophozoites with fibronectin.	trophozoites of entamoeba histolytica adhere to several components of the extracellular matrix. binding is mediated by specific receptors identified in the parasite surface. interaction of trophozoites with fn induces the formation of special adhesion structures that are dynamic cytoskeleton membrane complexes and facilitate both adhesion and substrate degradation. the process requires activation of signaling pathways in which plc, ip3, ca2-, and pkc participate. these observations, and recent e ...	1998	9806871
henoch schönlein purpura and amebiasis.	the pathogenesis of henoch schönlein purpura (hsp) is unknown but is believed to result from an immune complex reaction to various antigenic stimuli, such as infectious agents. however, its association with entamoeba histolytica has not been reported before. we present an 11-year-old boy with hsp, confirmed by the demonstration of leukocytoclastic vasculitis from skin and diffuse endocapillary proliferative glomerulonephritis, together with immunoglobulin a and complement component c3 deposition ...	1998	9821714
host-pathogen interaction in amebiasis and progress in vaccine development.	entamoeba histolytica, the causative organism of invasive intestinal and extraintestinal amebiasis, infects approximately 50 million people each year, causing an estimated 40 to 100 thousand deaths annually. because amebae only infect humans and some higher non-human primates, an anti-amebic vaccine could theoretically eradicate the organism. uncontrolled epidemiologic studies indicate that acquired immunity to amebic infection probably occurs and that such a vaccine might be feasible. applicati ...	1998	9832261
epithelial cell-initiated inflammation plays a crucial role in early tissue damage in amebic infection of human intestine.	entamoeba histolytica infection of the intestine can induce severe gut inflammation. the aims of this study were to assess the role of the host inflammatory response in the tissue damage observed with amebiasis and the role of the intestinal epithelial cell in initiating that response.	1998	9834272
case report: a patient who developed an amoebic liver abscess during treatment with interferon.	a 65-year-old female received recombinant interferon (ifn) alpha-2b daily for the treatment of chronic hepatitis c. fever (39 degrees c or higher) developed 14 days after the start of administration. abdominal computed tomography suggested multiple liver abscesses, which had not been detected before ifn administration. an autopsy revealed an amoebic liver abscess. a subclinical infection of entamoeba histolytica in this case developed into amoebic liver abscess during ifn administration.	1998	9835326
amoebic relaxant derived factor with activity on vascular smooth muscle.		1998	9836255
mucosal and systemic suppression of the immune response to e. histolytica provoked by metronidazole and mebendazole in balb/c mice.		1998	9836259
prevalence and epidemiologic characteristics of opportunistic and non-opportunistic intestinal parasitic infections in hiv positive patients in manipur.	a survey of the intestinal parasites among the hiv positive asymptomatic injecting drug users (idus) in manipur state in north-east india revealed the presence of three protozoan and two nematode species. of these, the two opportunistic parasitic protozoans i.e., cryptosporidium sp. (94.4 percent) and isospora sp. (10.7 percent) were predominant over entamoeba histolytica (5.6 percent), while non-opportunistic parasitic nematodes, i.e. ascaris lumbricoides (4.6 percent) and ancylostoma sp. (1 pe ...	1998	9842160
[validation in havana city, cuba of enzymeba, an immunoassay for detecting entamoeba histolytica in feces].	parasitologists from different medical institutions in havana city carried out the external validation of enzymeba, a diagnostic procedure of intestinal amebiasis developed at the "pedro kourí" institute of tropical medicine. to this end, serial faeces specimens from 212 individuals were collected and observed on the microscope (reference test). the enzymeba immunoassay (validation test) was also made. on comparing enzymeba with the microscopic examination, satisfactory indexes of sensitivity an ...	1998	9842262
the pyrophosphate-dependent phosphofructokinase of the protist, trichomonas vaginalis, and the evolutionary relationships of protist phosphofructokinases.	the pyrophosphate-dependent phosphofructokinase (ppi-pfk) of the amitochondriate protist trichomonas vaginalis has been purified. the enzyme is a homotetramer of about 50 kda subunits and is not subject to allosteric regulation. the protein was fragmented and a number of peptides were sequenced. based on this information a pcr product was obtained from t. vaginalis gdna and used to isolate corresponding cdna and gdna clones. southern analysis indicated the presence of five genes. one open readin ...	1998	9847416
royal society of tropical medicine and hygiene meeting at manson house, london, 19 february 1998. amoebic disease. entamoeba dispar, an organism reborn.	entamoeba dispar was described by emile brumpt in 1925, and was promptly dismissed as a synonym of e. histolytica by almost all his contemporaries. in the 1970s, however, evidence began to accumulate indicating that brumpt may have been correct and e. dispar is now accepted as a distinct species. this review introduces the organism's history and briefly summarizes what we currently know about its biology. the acceptance of e. dispar has profound implications for our understanding of the epidemio ...	1998	9850382
effect of bacterial association on virulence of entamoeba histolytica to baby hamster kidney cell monolayers.	axenic e. histolytica trophozoite strain nih:200 and hmi:imss when co-associated with aerobic bacteria escherichia coli strain k12 and serotype 056 showed marked increase in virulence as observed by destruction of baby hamster kidney (bhk) monolayers. however, when incubated with anaerobic bacterial strains clostridium perfringens and bacteroides fragilis virulence remained unaltered. further, adherence of e. histolytica to bhk monolayer was found to be mediated by n-acetyl-d-galactosamine.	1998	9854433
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
antiamoebic and phytochemical screening of some congolese medicinal plants.	results from the in vitro antiamoebic activity of some congolese plant extracts used as antidiarrhoeic in traditional medicine indicated that of 45 plant extracts tested, 35 (77.78%) exhibited an antiamoebic activity and 10 (22.22%) were inactive. the highest activity (mic < 100 microg/ml) was obtained with extracts from root bark of paropsia brazzeana, cryptolepis sanguinolenta, alchornea cordifolia, hensia pulchella, maprounea africana, rauwolfia obscura and voacanga africana, leaves and stem ...	1998	9687082
regulation of adherence and virulence by the entamoeba histolytica lectin cytoplasmic domain, which contains a beta2 integrin motif.	killing of human cells by the parasite entamoeba histolytica requires adherence via an amebic cell surface lectin. lectin activity in the parasite is regulated by inside-out signaling. the lectin cytoplasmic domain has sequence identity with a region of the beta2 integrin cytoplasmic tail implicated in regulation of integrin-mediated adhesion. intracellular expression of a fusion protein containing the cytoplasmic domain of the lectin has a dominant negative effect on extracellular lectin-mediat ...	1998	9693367
the novel core promoter element gaac in the hgl5 gene of entamoeba histolytica is able to direct a transcription start site independent of tata or initiator regions.	entamoeba histolytica, an enteric protozoa, is the third leading parasitic cause of death worldwide. investigation of the transcriptional machinery of this eukaryotic pathogen has revealed an unusual core promoter structure that consists of nonconsensus tata and initiator regions and a novel third conserved core promoter sequence, the gaac element. mutation of this region in the hgl5 promoter decreases reporter gene expression and alters the transcription start site. using positional analysis of ...	1998	9705300
effects of aphidicolin on entamoeba histolytica growth and dna synthesis.	we have previously demonstrated that dna polymerase activity of entamoeba histolytica is inhibited by aphidicolin, which is a specific inhibitor of eukaryotic nuclear replicative dna polymerases. the present study was aimed to evaluate the effect of aphidicolin on growth and dna synthesis by this parasite. aphidicolin blocked the growth of axenic e. histolytica strain hm-1:imss. dna synthesis was also inhibited by aphidicolin when assayed by incorporation of [3h]thymidine into the dna. the inhib ...	1998	9714225
substructural specificity and polyvalent carbohydrate recognition by the entamoeba histolytica and rat hepatic n-acetylgalactosamine/galactose lectins.	both the entamoeba histolytica lectin, a virulence factor for the causative agent of amebiasis, and the mammalian hepatic lectin bind to n-acetylgalactosamine (galnac) and galactose (gal) nonreducing termini on oligosaccharides, with preference for galnac. polyvalent galnac-derivatized neoglycoproteins have >1000-fold enhanced binding affinity for both lectins (adler,p., wood,s.j., lee,y.c., lee,r.t., petri,w.a.,jr. and schnaar,r.l.,1995, j. biol. chem ., 270, 5164-5171). substructural specifici ...	1998	9719685
identification and characterisation of early reactions of asparagine-linked oligosaccharide assembly in entamoeba histolytica.	sequential incubation of a mixed membrane fraction isolated from entamoeba histolytica trophozoites with the nonionic detergents brij 35 and igepal ca-630 rendered a soluble fraction with the ability to transfer n-acetylglucosamine (glcnac) from udp-glcnac to dolichol phosphate to form a lipid saccharide that was identified as a mixture of dolichol-p-p-glcnac and dolichol-p-p-(glcnac)2 as follows. (a) the reaction occurred only in the presence of exogenously added dolichol phosphate and was stro ...	1998	9770617
simultaneous amoebic liver abscess and hepatitis a infection.	hepatitis a virus (hav) infection and amoebic liver abscess have an identical mode of transmission (fecal-oral route) and similar epidemiology. either of these diseases might be considered in patients presenting with clinical signs and symptoms of liver disease in areas of the world where hepatitis and entamoeba histolytica are endemic. the following two cases describe patients with simultaneous infection of hav and amoebic liver abscess. this report emphasizes the role of dual infection in pati ...	1998	9772324
diagnosis of trichomonas vaginalis infection by pcr using vaginal swab samples.	trichomonas vaginalis infection is the most prevalent nonviral sexually transmitted disease (std) in the world. a pcr test using vaginal swab samples for the detection of t. vaginalis was developed to add t. vaginalis infection to the growing list of stds that can be detected by dna amplification techniques. a primer set, btub 9/2, was designed to target a well-conserved region in the beta-tubulin genes of t. vaginalis. all strains (15 of 15) of t. vaginalis tested were successfully detected by ...	1998	9774566
intestinal amoebiasis: antibody-secreting cells and humoral antibodies.	splenic plasma cell response and systemic antibody response to intestinal amoebiasis were studied in c3h/hej mice from 5 to 60 days post-inoculation with entamoeba histolytica. at various time intervals specific antibody-secreting cells (asc) in the spleen were measured in infected mice and non-infected control mice by enzyme-linked immunospot (elispot) assay. serum antibodies were measured by enzyme-linked immunosorbent assay (elisa). the infected animals showed high iga asc from 30 to 50 days ...	1998	9775574
some gastro-intestinal parasites of zoonotic (public health) importance commonly observed in old world non-human primates in kenya.	a study was undertaken to categorise some gastro-intestinal (git) parasites commonly observed in kenyan non-human primates (nhps) on the basis of their health implications for humans. six species of locally available non-human primates, namely olive baboons (papio cyanocephalus anubis), vervet monkey (cercopithecus aethiops), sykes monkey (cercopithecus mitis), black and white colobus (colobus abyssinicus), debrazzas monkey (cercopithecus neglectus) and grey and black mangabeys (cercocebus torqu ...	1998	9776144
involvement of the actin cytoskeleton and p21rho-family gtpases in the pathogenesis of the human protozoan parasite entamoeba histolytica.	it has been estimated that infection with the enteric protozoan parasite entamoeba histolytica kills more than 50,000 people a year. central to the pathogenesis of this organism is its ability to directly lyse host cells and cause tissue destruction. amebic lesions show evidence of cell lysis, tissue necrosis, and damage to the extracellular matrix. the specific molecular mechanisms by which these events are initiated, transmitted, and effected are just beginning to be uncovered. in this article ...	1998	9777011
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
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
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
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
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
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