| bone marrow dendritic cells from mice with an altered microbiota provide interleukin 17a-dependent protection against entamoeba histolytica colitis. | there is an emerging paradigm that the human microbiome is central to many aspects of health and may have a role in preventing enteric infection. entamoeba histolytica is a major cause of amebic diarrhea in developing countries. it colonizes the colon lumen in close proximity to the gut microbiota. interestingly, not all individuals are equally susceptible to e. histolytica infection. therefore, as the microbiota is highly variable within individuals, we sought to determine if a component of the ... | 2014 | 25370489 |
| entamoeba histolytica meningoencephalitis diagnosed by trophozoites in cerebrospinal fluid. | entamoeba histolytica meningoencephalitis has not been described in the modern literature, which is distinct from that caused by free-living amoebae. we report the first case of e. histolytica meningoencephalitis without liver or brain abscesses. cerebrospinal fluid revealed 2 + very motile trophozoites. our patient was successfully treated with intravenous metronidazole. | 2013 | 25356319 |
| degradation of the transcription factors nf-κb, stat3, and stat5 is involved in entamoeba histolytica-induced cell death in caco-2 colonic epithelial cells. | entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. during infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger il-8-mediated acute inflammatory responses. however, the signaling pathways involved in host cell death induced by e. histolytica have not yet been fully defined. in this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors d ... | 2014 | 25352693 |
| in vivo identification of the steps that control energy metabolism and survival of entamoeba histolytica. | the steps that control the entamoeba histolytica glycolytic flux were here identified by elasticity analysis, an experimental approach of metabolic control analysis. the concentrations of glycolytic metabolites were gradually varied in live trophozoites by (a) feeding with different glucose concentrations and (b) inhibiting the final pathway steps; in parallel, the changes in the pathway flux were determined. from the metabolite concentration-flux relationship, the elasticity coefficients of ind ... | 2015 | 25350227 |
| colonoscopic diagnosis of amebiasis: a case series and systematic review. | nonspecific gastrointestinal symptoms make diagnosis of amebiasis difficult. certain colonoscopic findings predict amebic colitis while others suggest different diagnoses. we aimed to evaluate the diagnostic capability of colonic evaluation of amebiasis. | 2015 | 25346004 |
| differentially expressed genes of virulent and nonvirulent entamoeba histolytica strains identified by suppression subtractive hybridization. | entamoeba histolytica is a parasite which presents capacity to degrade tissues and therefore has a pathogenic behavior. as this behavior is not shown by all strains, there have been several studies investigating molecular basis of the cytotoxicity process. using the suppression subtractive hybridization (ssh) technique, differential gene expressions of two e. histolytica strains, one virulent (egg) and one nonvirulent (452), have been analyzed with the purpose of isolating genes which may be inv ... | 2014 | 25313356 |
| [analysis of intestinal ameobiasis in patients with diarrhea by adhesin antigen test and direct microscopy]. | in this study, we aimed to research the frequency of intestinal amebiasis in patients who applied with diarrhea retrospectively for a year and compare direct microscopic analysis and elisa adhesin antigen test for entamoeba histolytica procedures. | 2014 | 25308451 |
| biochemical and kinetic characterization of the recombinant adp-forming acetyl coenzyme a synthetase from the amitochondriate protozoan entamoeba histolytica. | entamoeba histolytica, an amitochondriate protozoan parasite that relies on glycolysis as a key pathway for atp generation, has developed a unique extended ppi-dependent glycolytic pathway in which adp-forming acetyl-coenzyme a (coa) synthetase (acd; acetate:coa ligase [adp-forming]; ec 6.2.1.13) converts acetyl-coa to acetate to produce additional atp and recycle coa. we characterized the recombinant e. histolytica acd and found that the enzyme is bidirectional, allowing it to potentially play ... | 2014 | 25303954 |
| a novel alpha kinase ehak1 phosphorylates actin and regulates phagocytosis in entamoeba histolytica. | phagocytosis plays a key role in nutrient uptake and virulence of the protist parasite entamoeba histolytica. phagosomes have been characterized by proteomics, and their maturation in the cells has been studied. however, there is so far not much understanding about initiation of phagocytosis and formation of phagosomes at the molecular level. our group has been studying initiation of phagocytosis and formation of phagosomes in e. histolytica, and have described some of the molecules that play ke ... | 2014 | 25299184 |
| crystal structures and kinetics of type iii 3-phosphoglycerate dehydrogenase reveal catalysis by lysine. | d-phosphoglycerate dehydrogenase (pgdh) catalyzes the first committed step of the phosphorylated serine biosynthesis pathway. here, we report for the first time, the crystal structures of type iiik pgdh from entamoeba histolytica in the apo form, as well as in complexes with substrate (3-phosphoglyceric acid) and cofactor (nad(+) ) to 2.45, 1.8 and 2.2 å resolution, respectively. comparison of the apo structure with the substrate-bound structure shows that the substrate-binding domain is rotated ... | 2014 | 25294608 |
| the parasite entamoeba histolytica exploits the activities of human matrix metalloproteinases to invade colonic tissue. | intestinal invasion by the protozoan parasite entamoeba histolytica is characterized by remodelling of the extracellular matrix (ecm). the parasite cysteine proteinase a5 (cp-a5) is thought to cooperate with human matrix metalloproteinases (mmps) involved in ecm degradation. here, we investigate the role cp-a5 plays in the regulation of mmps upon mucosal invasion. we use human colon explants to determine whether cp-a5 activates human mmps. inhibition of the mmps' proteolytic activities abolishes ... | 2014 | 25291063 |
| interaction between nbp35 and cfd1 proteins of cytosolic fe-s cluster assembly reveals a stable complex formation in entamoeba histolytica. | iron-sulfur (fe-s) proteins are involved in many biological functions such as electron transport, photosynthesis, regulation of gene expression and enzymatic activities. biosynthesis and transfer of fe-s clusters depend on fe-s clusters assembly processes such as isc, suf, nif, and cia systems. unlike other eukaryotes which possess isc and cia systems, amitochondriate entamoeba histolytica has retained nif & cia systems for fe-s cluster assembly in the cytosol. in the present study, we have eluc ... | 2014 | 25271645 |
| microscopy versus enzyme linked immunosorbent assay test for detection of entamoeba histolytica infection in stool samples. | | 2014 | 25250240 |
| amoeboma of colon mimicking colonic carcinoma. | entamoeba histolytica is a major cause of diarrhea in the developing countries and it can present with a wide range of gastrointestinal symptoms depending on the phase of the infection. we describe a case of 65-year-old male patient presented with abdominal pain and vomiting. on the clinical and radiological examination provisional diagnosis of colonic carcinoma was suspected. after resection of perforated caecal growth, histopathological sections showed numerous trophozoites of e. histolytica i ... | 2014 | 25250235 |
| neglected tropical diseases among two indigenous subtribes in peninsular malaysia: highlighting differences and co-infection of helminthiasis and sarcocystosis. | soil-transmitted helminth (sth) infections have been documented among these minority groups since 1938. however the prevalence of sth is still high among these communities. most studies tend to consider the orang asli (indigenous) as a homogenous group. in contrary, different subtribes have their own cultural practices. to understand this variation better, we studied the prevalence and associated factors of sth and other gut parasitic infections among two common subtribes (i.e. temuan and temiar ... | 2014 | 25248116 |
| the mak16 gene of entamoeba histolytica and its identification in isolates from patients. | to identify sequences of entamoeba histolytica associated with the development of amebic liver abscess (ala) in hamsters, subtractive hybridization of cdna from e. histolytica hm-1:imss under 2 growth conditions was performed: 1) cultured in axenic medium and 2) isolated from experimental ala in hamsters. for this procedure, 6 sequences were obtained. of these sequences, the mak16 gene was selected for amplification in 29 cultures of e. histolytica isolated from the feces of 10 patients with int ... | 2014 | 25246723 |
| amoebic pi3k and pkc is required for jurkat t cell death induced by entamoeba histolytica. | the enteric protozoan parasite entamoeba histolytica is the causative agent of human amebiasis. during infection, adherence of e. histolytica through gal/galnac lectin on the surface of the amoeba can induce caspase-3-dependent or -independent host cell death. phosphorylinositol 3-kinase (pi3k) and protein kinase c (pkc) in e. histolytica play an important function in the adhesion, killing, or phagocytosis of target cells. in this study, we examined the role of amoebic pi3k and pkc in amoeba-ind ... | 2014 | 25246714 |
| identification of phosphatidylcholine transfer protein-like in the parasite entamoeba histolytica. | caveolin is the protein marker of caveola-mediated endocytosis. previously, we demonstrated by immunoblotting and immunofluorescence that an anti-chick embryo caveolin-1 monoclonal antibody (mab) recognizes a protein in amoeba extracts. nevertheless, the caveolin-1 gene is absent in the entamoeba histolytica genome database. in this work, the goal was to isolate, identify and characterize the protein that cross-reacts with chick embryo caveolin-1. we identified the protein using a proteomic appr ... | 2014 | 25223890 |
| a new human 3d-liver model unravels the role of galectins in liver infection by the parasite entamoeba histolytica. | investigations of human parasitic diseases depend on the availability of appropriate in vivo animal models and ex vivo experimental systems, and are particularly difficult for pathogens whose exclusive natural hosts are humans, such as entamoeba histolytica, the protozoan parasite responsible for amoebiasis. this common infectious human disease affects the intestine and liver. in the liver sinusoids e. histolytica crosses the endothelium and penetrates into the parenchyma, with the concomitant i ... | 2014 | 25211477 |
| gene expression profiling in entamoeba histolytica identifies key components in iron uptake and metabolism. | entamoeba histolytica is an ameboid parasite that causes colonic dysentery and liver abscesses in humans. the parasite encounters dramatic changes in iron concentration during its invasion of the host, with relatively low levels in the intestinal lumen and then relatively high levels in the blood and liver. the liver notably contains sources of iron; therefore, the parasite's ability to use these sources might be relevant to its survival in the liver and thus the pathogenesis of liver abscesses. ... | 2014 | 25210888 |
| ehcoactosin stabilizes actin filaments in the protist parasite entamoeba histolytica. | entamoeba histolytica is a protist parasite that is the causative agent of amoebiasis, and is a highly motile organism. the motility is essential for its survival and pathogenesis, and a dynamic actin cytoskeleton is required for this process. ehcoactosin, an actin-binding protein of the adf/cofilin family, participates in actin dynamics, and here we report our studies of this protein using both structural and functional approaches. the x-ray crystal structure of ehcoactosin resembles that of hu ... | 2014 | 25210743 |
| immunity in urogenital protozoa. | innate and adaptive immunity play a significant role in urogenital infections. innate immunity is provided by the epithelial cells and mucus lining along with acidic ph, which forms a strong physical barrier against the pathogens in female reproductive tract. cells of innate immune system, antimicrobial peptides, cytokines, chemokines and adaptive immunity in the reproductive tract are evolved during infection, and a pro-inflammatory response is generated to fight against the invading pathogen t ... | 2014 | 25201404 |
| rnai pathway genes are resistant to small rna mediated gene silencing in the protozoan parasite entamoeba histolytica. | the rna interference pathway in the protist entamoeba histolytica plays important roles in permanent gene silencing as well as in the regulation of virulence determinants. recently, a novel rna interference (rnai)-based silencing technique was developed in this parasite that uses a gene endogenously silenced by small rnas as a "trigger" to induce silencing of other genes that are fused to it. fusion to a trigger gene induces the production of gene-specific antisense small rnas, resulting in robu ... | 2014 | 25198343 |
| [ameboma: possible therapeutic decisions in an amebiasis-endemic region]. | amebiasis can mimic cecal tumors. unless this infection is diagnosed in a timely manner, affected individuals may undergo extensive surgery. | 2015 | 25195079 |
| duplex microfluidic sers detection of pathogen antigens with nanoyeast single-chain variable fragments. | quantitative and accurate detection of multiple biomarkers would allow for the rapid diagnosis and treatment of diseases induced by pathogens. monoclonal antibodies are standard affinity reagents applied for biomarkers detection; however, their production is expensive and labor-intensive. herein, we report on newly developed nanoyeast single-chain variable fragments (nyscfv) as an attractive alternative to monoclonal antibodies, which offers the unique advantage of a cost-effective production, s ... | 2014 | 25192256 |
| prevalence of entamoeba histolytica -like cysts compared to e. histolytica antigens detected by elisa in the stools of 600 patients from three socioeconomic communities in the metropolitan city of lahore, pakistan. | amoebiasis, caused by entamoeba histolytica , has a worldwide distribution and is of public health significance in many developing countries. it has a fecal-oral transmission cycle and is most prevalent in developing countries in regions where substandard sanitary conditions exist due to poverty. little is known about the epidemiology of e. histolytica infection and its presence in different socioeconomic communities in developing countries. we undertook the present study in the city of lahore, ... | 2015 | 25189631 |
| entamoeba histolytica acetyl-coa synthetase: biomarker of acute amoebic liver abscess. | to characterize the entamoeba histolytica (e. histolytica) antigen(s) recognized by moribound amoebic liver abscess hamsters. | 2014 | 25182945 |
| invasive amoebiasis: a review of entamoeba infections highlighted with case reports. | entamoeba histolytica infections of the gastrointestinal tract are common in the developing world but rare in north america. the authors present two cases: one involving an individual who had not travelled to an endemic area and another involving an individual who was born in bulgaria. both presented with severe abdominal pain and diarrhea. endoscopic assessment revealed scattered colonic ulcerations and one patient was found to have a liver abscess on imaging. stool ova and parasite studies wer ... | 2016 | 25157525 |
| an uncommon case of hepatopulmonary amoebiasis. | amoebiasis is an uncommon infection in developed countries caused by the protozoan entamoeba histolytica. amoebic liver abscess is the most frequent extraintestinal presentation of the disease; pleuropulmonary involvement is rare, occurring mostly by rupture of the abscess into the pleural space or lung parenchyma. we describe a case of a 48-year-old migrant from são tomé e príncipe, with fever, wasting, dry cough and right upper abdominal pain for the past 2 months. the ct scan revealed a volum ... | 2014 | 25155487 |
| flavodiiron oxygen reductase from entamoeba histolytica: modulation of substrate preference by tyrosine 271 and lysine 53. | flavodiiron proteins (fdps) are a family of enzymes endowed with bona fide oxygen- and/or nitric-oxide reductase activity, although their substrate specificity determinants remain elusive. after a comprehensive comparison of available three-dimensional structures, particularly of fdps with a clear preference toward either o2 or no, two main differences were identified near the diiron active site, which led to the construction of site-directed mutants of tyr(271) and lys(53) in the oxygen reducin ... | 2014 | 25151360 |
| in vitro antiamoebic activity evaluation and docking studies of metronidazole-triazole hybrids. | an in-house database of 520 compounds was docked against entamoeba histolytica thioredoxin reductase (ehtrr), a promising target for the treatment of amoebiasis. amongst these, some metronidazole (mtz)-triazole hybrids were ranked high, with docking scores from -10.23 to -7.56. studies of the binding orientations and conformations show that the head groups of mtz-triazole hybrids interact with the arginine residues within the binding pocket of ehtrr, making it clear that such is the optimal and ... | 2014 | 25146853 |
| genetic analysis of enterobius vermicularis isolated from a chimpanzee with lethal hemorrhagic colitis and pathology of the associated lesions. | human pinworms, enterobius vermicularis, are normally recognized as minor pathogens. however, a fatal case of human pinworm infection has been reported in a nonhuman primate, a zoo reared chimpanzee. here, we histopathologically examined the lesions in tissues from the deceased chimpanzee and genetically characterized the isolated worms to investigate the pathogenicity and determine the phylogeny. we identified ulcers deep in the submucosa where many parasites were found to have invaded the lami ... | 2014 | 25138069 |
| genetic variability of the serine-rich entamoeba histolytica protein gene in clinical isolates from the united arab emirates. | the genetic diversity of 20 entamoeba histolytica isolates from asymptomatic individuals from the uae was investigated by analyzing polymorphism in the serine-rich e. histolytica gene (srehp) by nested polymerase chain reaction (pcr) amplification followed by restriction fragment length polymorphism (rflp) on dna extracted directly from stool samples. the srehp gene was successfully amplified in 15 out of 20 e. histolytica-positive samples. four out of the remaining five isolates did not amplify ... | 2014 | 25134907 |
| proteomic analysis of entamoeba histolytica in vivo assembled pre-mrna splicing complexes. | the genome of the human intestinal parasite entamoeba histolytica contains nearly 3000 introns and bioinformatic predictions indicate that major and minor spliceosomes occur in entamoeba. however, except for the u2-, u4-, u5- and u6 snrnas, no other splicing factor has been cloned and characterized. here, we ha-tagged cloned the snrnp component u1a and assessed its expression and nuclear localization. because the snrnp-free u1a form interacts with polyadenylate-binding protein, ha-u1a immunoprec ... | 2014 | 25109466 |
| cellular and proteomics analysis of the endomembrane system from the unicellular entamoeba histolytica. | entamoeba histolytica is the protozoan parasite agent of amoebiasis, an infectious disease of the human intestine and liver. specific active pathogenic factors are secreted toward the external milieu upon interaction of the parasite with human tissue. trafficking dynamics and secretion of these factors is not known and characterization of the dynamics interplay of subcellular compartments such as the er or golgi apparatus is still pending. in this work, we took advantage of cell fractionation an ... | 2015 | 25109464 |
| noninvasive intestinal amebiasis: entamoeba histolytica colonization without invasion. | entamoeba histolytica infection remains a major cause of morbidity and mortality worldwide. although research with the organism began in the late nineteenth century, our understanding of the natural history of the infection remains incomplete and is heavily based on expert opinion. most persons infected with e. histolytica are carriers with the organism colonizing the large intestine. host defense mechanisms that prevent invasive diseases are poorly understood. a timely review could lead to rene ... | 2014 | 25101557 |
| serological surveillance development for tropical infectious diseases using simultaneous microsphere-based multiplex assays and finite mixture models. | a strategy to combat infectious diseases, including neglected tropical diseases (ntds), will depend on the development of reliable epidemiological surveillance methods. to establish a simple and practical seroprevalence detection system, we developed a microsphere-based multiplex immunoassay system and evaluated utility using samples obtained in kenya. | 2014 | 25078404 |
| regulation of gene expression in the protozoan parasite entamoeba invadens: identification of core promoter elements and promoters with stage-specific expression patterns. | developmental switching between life-cycle stages is a common feature among many pathogenic organisms. entamoeba histolytica is an important human pathogen and is a leading parasitic cause of death globally. during its life cycle, entamoeba converts between cysts (essential for disease transmission) and trophozoites (responsible for tissue invasion). despite being central to its biology, the triggers that are involved in the developmental pathways of this parasite are not well understood. in ord ... | 2014 | 25075445 |
| hypocholesterolemia in patients with an amebic liver abscess. | many parasites induce changes in the lipid profiles of the host. cholesterol increases the virulence of entamoeba histolytica in animal models and in vitro culture. this study aimed to determine, in patients with an amebic liver abscess, the correlation between cholesterol and other features, such as the size and number of abscesses, standard hematological and serum chemistry profiles, liver tests, and duration of hospital stay. | 2014 | 25071907 |
| amoebic anal fistula: new insight into an old disease. | a 67-year-old gentleman underwent fistulectomy for low trans-sphincteric anal fistula along with curettage for an associated abscess extending proximally for half a centimeter into the intersphincteric plane. the roof of the cavity became clearly visible after satisfactory culmination of the surgical procedure. histopathological examination of the fistulous tract and the curetted granulation tissue revealed presence of multiple trophozoites of entamoeba histolytica exhibiting erythrophagocytosis ... | 2014 | 25053686 |
| repurposing the open access malaria box to discover potent inhibitors of toxoplasma gondii and entamoeba histolytica. | toxoplasmosis and amebiasis are important public health concerns worldwide. the drugs currently available to control these diseases have proven limitations. therefore, innovative approaches should be adopted to identify and develop new leads from novel scaffolds exhibiting novel modes of action. in this paper, we describe results from the screening of compounds in the medicines for malaria venture (mmv) open access malaria box in a search for new anti-toxoplasma and anti-entamoeba agents. standa ... | 2014 | 25049259 |
| asymptomatic intestinal amebiasis in japanese hiv-1-infected individuals. | seventy-one asymptomatic human immunodeficiency virus-1 (hiv-1) -infected individuals who underwent colonoscopy for detection of diseases other than amebiasis were included in this study. ulcerative lesions caused by entamoeba histolytica were identified by colonoscopy and biopsy in 11.3% (8 of 71) of individuals. stool microscopic examination hardly identified entamoeba, whereas serum antibody against e. histolytica was often elevated in patients with subclinical intestinal amebiasis. human leu ... | 2014 | 25048374 |
| dna extraction from protozoan oocysts/cysts in feces for diagnostic pcr. | pcr detection of intestinal protozoa is often restrained by a poor dna recovery or by inhibitors present in feces. the need for an extraction protocol that can overcome these obstacles is therefore clear. qiaamp® dna stool mini kit (qiagen) was evaluated for its ability to recover dna from oocysts/cysts directly from feces. twenty-five giardia-positive, 15 cryptosporidium-positive, 15 entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoa ... | 2014 | 25031466 |
| caecal amebic colitis mimicking obstructing right sided colonic carcinoma with liver metastases: a rare case. | intestinal entamoeba histolytica infection can lead to colitis, abscess formation, colonic perforation and rarely amoeboma. we report a case of colonic amoebiasis, in which the presenting symptoms and radiological findings closely resembled an obstructing right-sided colonic carcinoma, with liver metastases. | 2016 | 25022419 |
| recent advances in molecular biology of parasitic viruses. | the numerous protozoa that can inhabit the human gastro-intestinal tract are known, yet little is understood of the viruses which infect these protozoa. the discovery, morphologic details, purification methods of virus-like particles, genome and proteome of the parasitic viruses, entamoeba histolytica, giardia lamblia, trichomonas vaginalis, and the eimeria sp. are described in this review. the protozoan viruses share many common features: most of them are rna or double-stranded rna viruses, ran ... | 2014 | 25019235 |
| entamoeba histolytica adaptation to glucose starvation: a matter of life and death. | parasites are often challenged by constant changes of the glucose concentration in their different hosts and/or within the different biotopes in the same host. during its life cycle, entamoeba histolytica, the causative protozoan parasite of human amoebiasis, is exposed to both a glucose-poor environment in the colon and a glucose-rich environment in the liver. high-throughput 'omics' technologies are now widely used to characterize the cell's global response to various stresses and these techno ... | 2014 | 25016247 |
| differential expression and immunolocalization of antioxidant enzymes in entamoeba histolytica isolates during metronidazole stress. | entamoeba histolytica infections are endemic in the indian subcontinent. five to eight percent of urban population residing under poor sanitary conditions suffers from entamoeba infections. metronidazole is the most widely prescribed drug used for amoebiasis. in order to understand the impact of metronidazole stress on the parasite, we evaluated the expression of two antioxidant enzymes, peroxiredoxin and fesod, in entamoeba histolytica isolates during metronidazole stress. the results reveal th ... | 2014 | 25013795 |
| crystallization and preliminary x-ray analysis of rabx3, a tandem gtpase from entamoeba histolytica. | ras superfamily gtpases regulate signalling pathways that control multiple biological processes by modulating the gtp/gdp cycle. various rab gtpases, which are the key regulators of vesicular trafficking pathways, play a vital role in the survival and virulence of the enteric parasite entamoeba histolytica. the rab gtpases act as binary molecular switches that utilize the conformational changes associated with the gtp/gdp cycle to elicit responses from target proteins and thereby regulate a broa ... | 2014 | 25005092 |
| structural elucidation of a dual-activity pap phosphatase-1 from entamoeba histolytica capable of hydrolysing both 3'-phosphoadenosine 5'-phosphate and inositol 1,4-bisphosphate. | the enzyme 3'-phosphoadenosine 5'-phosphatase-1 (pap phosphatase-1) is a member of the li(+)-sensitive mg(2+)-dependent phosphatase superfamily, or inositol monophosphatase (impase) superfamily, and is an important regulator of the sulfate-activation pathway in all living organisms. inhibition of this enzyme leads to accumulation of the toxic byproduct 3'-phosphoadenosine 5'-phosphate (pap), which could be lethal to the organism. genomic analysis of entamoeba histolytica suggests the presence of ... | 2014 | 25004978 |
| regulation of virulence of entamoeba histolytica. | entamoeba histolytica is the third-leading cause of parasitic mortality globally. e. histolytica infection generally does not cause symptoms, but the parasite has potent pathogenic potential. the origins, benefits, and triggers of amoebic virulence are complex. amoebic pathogenesis entails depletion of the host mucosal barrier, adherence to the colonic lumen, cytotoxicity, and invasion of the colonic epithelium. parasite damage results in colitis and, in some cases, disseminated disease. both ho ... | 2014 | 25002094 |
| proteomic analysis identifies endoribouclease ehl-psp and ehrrp41 exosome protein as novel interactors of ehcaf1 deadenylase. | in higher eukaryotic cells mrna degradation initiates by poly(a) tail shortening catalyzed by deadenylases caf1 and ccr4. in spite of the key role of mrna turnover in gene expression regulation, the underlying mechanisms remain poorly understood in parasites. here, we aimed to study the function of ehcaf1 and identify associated proteins in entamoeba histolytica. by biochemical assays, we evidenced that ehcaf1 has both rna binding and deadenylase activities in vitro. ehcaf1 was located in cytopl ... | 2014 | 24998979 |
| liver abscess in the tropics: an experience from jammu. | to study the various types of liver abscesses. this prospective study was conducted over a period of one year, from november 2011 to october 2012, at the department of general surgery in acharya shri chander college of medical sciences and hospital sidhra, jammu. | 2014 | 24996785 |
| balantidiosis: a rare accidental finding in the urine of a patient with acute renal failure. | balantidium coli is the only ciliated protozoan which is known to infect human and nonhuman primates. route of infection is faecal-oral route. it is actively motile and causes mostly asymptomatic infections, or it may develop dysentery which is similar to that which is caused by entamoeba histolytica. here, we are describing a case of an accidental finding of b.coli in the urine of a patient who presented with acute renal failure, based on its characteristic morphology and motility which were se ... | 2014 | 24995185 |
| modified pehps medium as an alternative for the in vitro culture of giardia lamblia. | commercial culture media present interlot variations in biological activity. we have previously designed a homemade and economic culture medium, pehps medium, for the axenic cultivation of entamoeba histolytica and trichomonas vaginalis. trophozoites of amoebae and trichomonads grow well in this medium. furthermore, the medium is stable for several months when stored frozen or refrigerated. the objective of this work was to modify pehps medium to support the in vitro growth of giardia lamblia. i ... | 2014 | 24982905 |
| antiprotozoal activity of 8-acyl and 8-alkyl incomptine a analogs. | the activities of 11 c-8-o-acyl and alkyl analogs of the antiprotozoal sesquiterpene lactone, incomptine a (1) against entamoeba histolytica and giardia lamblia, were determined. here, the effects of different lengths and amounts of branching of the acyl and alkyl groups on the antiprotozoal activity of the synthesized incomptine a-analogs are reported. | 2014 | 24974343 |
| in vitro genotoxic and mutagenic evaluation of the aqueous extract of codiaeum variegatum and its amoebicidal sub-fraction. | codiaeum variegatum, grown in many varieties, has been widely used as a houseplant based on its brightly decorative foliage. in addition, a variety of this plant has been used for a long time against bloody diarrhea by the local population in cameroon. | 2014 | 24971796 |
| analysis of the epithelial damage produced by entamoeba histolytica infection. | entamoeba histolytica is the causative agent of human amoebiasis, a major cause of diarrhea and hepatic abscess in tropical countries. infection is initiated by interaction of the pathogen with intestinal epithelial cells. this interaction leads to disruption of intercellular structures such as tight junctions (tj). tj ensure sealing of the epithelial layer to separate host tissue from gut lumen. recent studies provide evidence that disruption of tj by the parasitic protein ehcpadh112 is a prere ... | 2014 | 24962382 |
| ip6k structure and the molecular determinants of catalytic specificity in an inositol phosphate kinase family. | inositol trisphosphate kinases (ip3ks) and inositol hexakisphosphate kinases (ip6ks) each regulate specialized signalling activities by phosphorylating either insp3 or insp6 respectively. the molecular basis for these different kinase activities can be illuminated by a structural description of ip6k. here we describe the crystal structure of an entamoeba histolytica hybrid ip6k/ip3k, an enzymatic parallel to a 'living fossil'. through molecular modelling and mutagenesis, we extrapolated our find ... | 2014 | 24956979 |
| metabolomic analysis of entamoeba: applications and implications. | entamoeba histolytica is an enteric protozoan parasite that causes hemorrhagic dysentery and extraintestinal abscesses in millions of inhabitants of endemic areas. the genome of e. histolytica has already been sequenced and used to predict the metabolic potential of the organism. since nearly 56% of the e. histolytica genes remain unannotated, correlative 'omics' analyses of genomics, transcriptomics, proteomics, and biochemical metabolic profiling are essential in uncovering new, or poorly unde ... | 2014 | 24950028 |
| inferior vena cava thrombosis in a case of amoebic liver abscess: is hypercomplementemia responsible for this rare entity? | among the liver abscesses, thrombosis of the inferior vena cava (ivc) has been reported mainly in amoebic liver abscess (ala) caused by entamoeba histolytica (e.h). it is an unusual complication especially in paediatric age group. association of hypercomplementemia and ivc thrombosis has not been discussed previously. published data suggest that e.h can activate the complement system and can cause hypercomplementemia. a very few studies suggest that complement activation and hypercomplementemia ... | 2014 | 24943781 |
| destabilization domain approach adapted for regulated protein expression in the protozoan parasite entamoeba histolytica. | a plethora of information has been gained by sequencing the genome of the human parasite entamoeba histolytica, however a lack of robust genetic tools hampers experimental elucidation of gene functions. we adapted the destabilization domain approach for modulation of protein levels in e. histolytica using the destabilization domains of fk506 binding protein (ddfkbp) and dihydrofolate reductase (dddhfr), respectively. in our studies, the ddfkbp appears to be more tightly regulated than dddhfr, wi ... | 2014 | 24929134 |
| atomic resolution crystal structure of vclmwptp-1 from vibrio cholerae o395: insights into a novel mode of dimerization in the low molecular weight protein tyrosine phosphatase family. | low molecular weight protein tyrosine phosphatase (lmwptp) is a group of phosphotyrosine phosphatase ubiquitously found in a wide range of organisms ranging from bacteria to mammals. dimerization in the lmwptp family has been reported earlier which follows a common mechanism involving active site residues leading to an enzymatically inactive species. here we report a novel form of dimerization in a lmwptp from vibrio cholera 0395 (vclmwptp-1). studies in solution reveal the existence of the dime ... | 2014 | 24909685 |
| ligand heterogeneity of the cysteine protease binding protein family in the parasitic protist entamoeba histolytica. | lysosomal soluble proteins are targeted to endosomes and lysosomes by specific receptors resident in the endoplasmic reticulum and/or the golgi apparatus. the enteric protozoan parasite entamoeba histolytica has a novel class of lysosomal targeting receptors, named the cysteine protease binding protein family (cpbf). among 11 cpbfs (cpbf1-11), ligands for three members, cpbf1, cpbf6 and cpbf8, were previously shown to be cysteine proteases, α- and γ- amylases, and β-hexosaminidase and lysozymes, ... | 2014 | 24907554 |
| ultrastructural characteristics and molecular identification of entamoeba suis isolated from pigs with hemorrhagic colitis: implications for pathogenicity. | protozoan parasites of the genus entamoeba infect many classes of vertebrates and are primarily classified based on morphological criteria. to date, only a few species have been proven to cause disease. here, we examined the pathology of infected pigs with hemorrhage and detected entamoeba parasites. isolates were characterized genetically and ultrastructurally to identify the species. histopathologically, bleeding and thrombus formation were seen only in the large intestine mucosa, where a larg ... | 2014 | 24894081 |
| the flavonoid (-)-epicatechin affects cytoskeleton proteins and functions in entamoeba histolytica. | human amoebiasis is an intestinal disease with a global distribution. due to reports of parasite resistance or susceptibility reduction to metronidazole treatment, there is a renewed interest for the search of new molecules with antiamoebic activity. the flavonoid (-)-epicatechin that was isolated from the mexican medicinal plant geranium mexicanum hbk has an in vitro activity against e. histolytica trophozoites, however its molecular effects have been poorly documented. using a proteomic approa ... | 2014 | 24887480 |
| structural and mutational analysis of amino acid residues involved in atp specificity of escherichia coli acetate kinase. | acetate kinase (ak) generally utilizes atp as a phosphoryl donor, but ak from entamoeba histolytica (ppi-ehiak) uses pyrophosphate (ppi), not atp, and is ppi-specific. the determinants of the phosphoryl donor specificity are unknown. here, we inferred 5 candidate amino acid residues associated with this specificity, based on structural information. each candidate residue in escherichia coli atp-specific ak (atp-ecoak), which is unable to use ppi, was substituted with the respective ppi-ehiak ami ... | 2014 | 24856051 |
| epidemiological features of intestinal infection with entamoeba histolytica in taiwan, 2002-2010. | amebiasis remains an important public health problem worldwide, and immigration and an increase in international travel have affected the incident cases of the disease. the purpose of this study was to assess the prevalence of entamoeba histolytica in taiwan between 2002 and 2010. we analyzed data from surveillance programs run by the centers for disease control, taiwan (taiwan cdc), and only laboratory-confirmed cases were analyzed. in total, 1796 cases with e. histolytica infections were inclu ... | 2014 | 24837854 |
| peroxynitrite and peroxiredoxin in the pathogenesis of experimental amebic liver abscess. | the molecular mechanisms by which entamoeba histolytica causes amebic liver abscess (ala) are still not fully understood. amebic mechanisms of adherence and cytotoxic activity are pivotal for amebic survival but apparently do not directly cause liver abscess. abundant evidence indicates that chronic inflammation (resulting from an inadequate immune response) is probably the main cause of ala. reports referring to inflammatory mechanisms of liver damage mention a repertoire of toxic molecules by ... | 2014 | 24822193 |
| hsp90 inhibitors as new leads to target parasitic diarrheal diseases. | entamoeba histolytica and giardia lamblia are anaerobic protozoan parasites that cause amebiasis and giardiasis, two of the most common diarrheal diseases worldwide. current therapy relies on metronidazole, but resistance has been reported and the drug has significant adverse effects. therefore, it is critical to search for effective, better-tolerated antiamebic and antigiardial drugs. we synthesized several examples of a recently reported class of hsp90 inhibitors and evaluated these compounds ... | 2014 | 24820073 |
| vagotomy induces deregulation of the inflammatory response during the development of amoebic liver abscess in hamsters. | the parasympathetic nervous system modulates the immune response in the abdominal-pelvic gut through the vagus nerve, which releases acetylcholine. this endogenous ligand acts on α7 nicotinic receptors expressed on immune cells. | 2015 | 24819982 |
| the macrophage migration inhibitory factor homolog of entamoeba histolytica binds to and immunomodulates host macrophages. | the host inflammatory response contributes to the tissue damage that occurs during amebic colitis, with tumor necrosis factor alpha (tnf-α) being a key mediator of the gut inflammation observed. mammalian macrophage migration inhibitory factor (mif) is a proinflammatory cytokine that plays an important role in the exacerbation of a wide range of inflammatory diseases, including colitis. we identified a mif gene homolog in the entamoeba histolytica genome, raising the question of whether e. histo ... | 2014 | 24818664 |
| conformational changes induced by detergents during the refolding of chemically denatured cysteine protease ppehcp-b9 from entamoeba histolytica. | ehcp-b9, a cysteine protease (cp) involved in entamoeba histolytica virulence, is a potential target for disease diagnosis and drug design. after purification from inclusion bodies produced in escherichia coli, the recombinant ehcp-b9 precursor (ppehcp-b9) can be refolded using detergents as artificial chaperones. however, the conformational changes that occur during ppehcp-b9 refolding remain unknown. here, we comprehensively describe conformational changes of ppehcp-b9 that are induced by vari ... | 2014 | 24769005 |
| new evidence of entamoeba histolytica infections in pre-columbian and colonial cemeteries in the caribbean. | elisa was used to test the presence of the human pathogenic amoeba entamoeba histolytica in archaeological samples from 2 cemeteries in guadeloupe, in the caribbean. results show that 15.9% of the population was infected during the colonial period, a value comparable to the current rates observed in humans in adjacent countries. this study also confirms the presence of the current strain of e. histolytica in pre-columbian south america before the european colonization in the 15th century and rai ... | 2014 | 24766261 |
| hepatopleuropulmonary amoebiasis--a case report. | amoebiasis is a food-borne protozoan infection, caused by entamoeba histolytica. here a case of hepatopleuropulmonary amoebiasis, which was detected after fibre-optic bronchoscopy is reported. bronchial aspirate showed trophozoites of entamoeba histolytica. the patient was treated with tinidazole and responded favourably. | 2013 | 24765700 |
| amoebicidal activity of essential oil of dysphania ambrosioides (l.) mosyakin & clemants in an amoebic liver abscess hamster model. | amebiasis is a parasitic disease that extends worldwide and is a public health problem in developing countries. metronidazole is the drug recommended in the treatment of amebiasis, but its contralateral effects and lack of continuity of treatment induce low efficiency, coupled with the appearance of resistant amoebic strains. therefore, the search of new compounds with amoebicidal activity is urgent and important. in this study, we evaluated the in vitro and in vivo antiamoebic activity of the e ... | 2014 | 24757495 |
| genital infection caused by entamoeba histolytica confirmed by polymerase chain reaction analyses. | entamoeba histolytica is estimated to infect approximately 1% of the global population. in japan, the prevalence of amebic dysentery has been increasing, with more than 800 patients newly diagnosed annually. however, genital infection with e. histolytica is uncommon even in endemic areas. we present a case of vaginitis caused by e. histolytica. a 50-year-old japanese woman without history of overseas travel presented to a nearby clinic with increased vaginal discharge. she had hemorrhagic erosio ... | 2014 | 24750396 |
| water-soluble ruthenium complexes bearing activity against protozoan parasites. | parasitic illnesses are major causes of human disease and misery worldwide. among them, both amebiasis and chagas disease, caused by the protozoan parasites, entamoeba histolytica and trypanosoma cruzi, are responsible for thousands of annual deaths. the lack of safe and effective chemotherapy and/or the appearance of current drug resistance make the development of novel pharmacological tools for their treatment relevant. in this sense, within the framework of the medicinal inorganic chemistry, ... | 2014 | 24740394 |
| proteomic profiling reveals that ehpc4 transcription factor induces cell migration through up-regulation of the 16-kda actin-binding protein ehabp16 in entamoeba histolytica. | actin cytoskeleton is an essential structure involved in cell migration and invasion in parasites. in entamoeba histolytica, the protozoan parasite causing human amoebiasis, the mechanisms underlying the expression of migration-related genes are poorly understood. here, we investigated the biological effects of ectopic overexpression of ehpc4 (positive coactivator 4) in cell migration of e. histolytica trophozoites. using differential in gel two-dimensional electrophoresis, 33 modulated proteins ... | 2014 | 24721673 |
| naegleria fowleri: contact-dependent secretion of electrondense granules (edg). | the free living amoeba naegleria fowleri is pathogenic to humans but also to other mammalians. these amoebae may invade the nasal mucosa and migrate into the brain causing cerebral hemorrhagic necrosis, a rapidly fatal infection. knowledge of the cytolytic mechanism involved in the destruction of brain tissues by naegleria trophozoites is limited. in other amoebic species, such as entamoeba histolytica, we have previously reported the possible lytic role of small cytoplasmic components endowed w ... | 2014 | 24721258 |
| unusual findings in appendectomy specimens of adults: retrospective analyses of 1466 patients and a review of literature. | diseases and tumors of the appendix vermiformis are very rare, except acute appendicitis. | 2014 | 24719727 |
| trogocytosis by entamoeba histolytica contributes to cell killing and tissue invasion. | entamoeba histolytica is the causative agent of amoebiasis, a potentially fatal diarrhoeal disease in the developing world. the parasite was named "histolytica" for its ability to destroy host tissues, which is probably driven by direct killing of human cells. the mechanism of human cell killing has been unclear, although the accepted model was that the parasites use secreted toxic effectors to kill cells before ingestion. here we report the discovery that amoebae kill by ingesting distinct piec ... | 2014 | 24717428 |
| production of recombinant entamoeba histolytica pyruvate phosphate dikinase and its application in a lateral flow dipstick test for amoebic liver abscess. | amoebic liver abscess (ala) is the most common clinical manifestation of extraintestinal amoebiasis especially in developing countries, causing up to 100 000 fatal cases annually. accurate and early diagnosis is important to prevent the disease complications, however its diagnosis still poses many challenges due to the limitations of the available detection tools. pyruvate phosphate dikinase (ppdk), an excretory-secretory protein of e. histolytica, has been reported as a potential diagnostic mar ... | 2014 | 24708664 |
| the awareness of health professionals in diagnostic techniques for intestinal parasites in gaza strip, palestine. | diagnosis of intestinal parasites still depends on conventional methods in gaza strip hospitals and private laboratories. | 2014 | 24669336 |
| amebic liver abscess: fine needle aspiration diagnosis. | to describe the findings in fine needle aspiration (fna) of an amebic liver abscess (ala). | 2014 | 24662424 |
| parasitic infections of the appendix as a cause of appendectomy in adult patients. | assessment of frequency and clinical findings of parasitic infections for etiology of acute appendicitis. | 2014 | 24659695 |
| natural infection of baboons by entamoeba histolytica elicits anti- gal-lectin heavy subunit iga and igg antibodies with shared epitope specificity to that of humans. | non-human primates, such as baboons (papio hamadryas anubis), are natural hosts for entamoeba species; infections can be asymptomatic or result in invasive lethal disease. it was sought to determine whether following natural infection by entamoeba. histolytica, baboon anti-amebic antibodies recognized native gallectin, a recombinant portion of the lectin heavy subunit (designated lc3) and specific heavy subunit epitopes; we compared the specificity of anti-amebic antibodies from baboons to that ... | 2013 | 24640872 |
| analysis of u3 snorna and small subunit processome components in the parasitic protist entamoeba histolytica. | in the early branching parasitic protist entamoeba histolytica, pre-rrna synthesis continues when cells are subjected to growth stress, but processing slows down and unprocessed pre-rrna accumulates. to gain insight into the regulatory mechanisms leading to accumulation, it is necessary to define the pre-rrna processing machinery in e. histolytica. we searched the e. histolytica genome sequence for homologs of the ssu processome, which contains the u3snorna, and 72 proteins in yeast. we could id ... | 2014 | 24631428 |
| proteomic identification of s-nitrosylated proteins in the parasite entamoeba histolytica by resin-assisted capture: insights into the regulation of the gal/galnac lectin by nitric oxide. | entamoeba histolytica is a gastrointestinal protozoan parasite that causes amebiasis, a disease which has a worldwide distribution with substantial morbidity and mortality. nitrosative stress, which is generated by innate immune cells, is one of the various environmental challenges that e. histolytica encounters during its life cycle. although the effects of nitric oxide (no) on the regulation of gene expression in this parasite have been previously investigated, our knowledge on s-nitrosylated ... | 2014 | 24626316 |
| post-travel screening of asymptomatic long-term travelers to the tropics for intestinal parasites using molecular diagnostics. | the incidence of asymptomatic travel-related parasitic infection is uncertain. previous studies did not distinguish new incident infections, from past infections. regardless of symptoms, we performed multiplex real-time polymerase chain reaction on pre- and post-travel stool samples of dutch long-term travelers to the (sub)tropics. serological screening for schistosoma spp. was only performed in travelers to sub-saharan africa. in total, 679 travelers were included in the study. the follow-up ra ... | 2014 | 24615130 |
| entamoeba histolytica: gene expression analysis of cells invading tissues. | entamoeba histolytica is a protozoan parasite that presents a risk to the health of millions of people worldwide. due to the existence of different clinical forms caused by the parasite and also different virulence levels presented by one strain, one would expect differences in the profile of gene transcripts between virulent and nonvirulent cultures. in this study we used the differential display to select gene segments related to invasiveness of amoeba. one brazilian strain of e. histolytica i ... | 2014 | 24605052 |
| laboratory diagnosis of amebiasis in a sample of students from southeastern brazil and a comparison of microscopy with enzyme-linked immunosorbent assay for screening of infections with entamoeba sp. | epidemiological studies on amebiasis have been reassessed since entamoeba histolytica and e. dispar were first recognized as distinct species. because the morphological similarity of these species renders microscopic diagnosis unreliable, additional tools are required to discriminate between entamoeba species. the objectives of our study were to compare microscopy with elisa kit (ivd®) results, to diagnose e. histolytica infection, and to determine the prevalence of amebiasis in a sample of stud ... | 2014 | 24603737 |
| the entamoeba histolytica dnmt2 homolog (ehmeth) confers resistance to nitrosative stress. | nitric oxide (no) has antimicrobial properties against many pathogens due to its reactivity as an s-nitrosylating agent. it inhibits many of the key enzymes that are involved in the metabolism and virulence of the parasite entamoeba histolytica through s-nitrosylation of essential cysteine residues. very little information is available on the mechanism of resistance to no by pathogens in general and by this parasite in particular. here, we report that exposure of the parasites to s-nitrosoglutat ... | 2014 | 24562908 |
| risk factors for intestinal parasitosis among antiretroviral-treated hiv/aids patients in ethiopia. | summary a cross-sectional survey was conducted to determine the risk factors associated with intestinal parasitosis in hiv/aids patients receiving antiretroviral therapy (art). socio-demographic information was collected and faecal samples were analysed from 384 randomly selected patients on art. data on cd4+ t-cell counts and world health organization clinical staging were obtained from the medical records at the hospital. the overall prevalence of intestinal parasitosis was 56% (95% confidence ... | 2014 | 24554001 |
| unusual multiple large abscesses of the liver: interest of the radiological features and the real-time pcr to distinguish between bacterial and amebic etiologies. | we report a rare case of amebiasis generating 19 large liver abscesses. such a quantity of abscesses is rare, especially when occurring in a young casual traveler without any immunodeficiency disorders. a possible co-infection was excluded. by contrast, the amebic etiology was confirmed by means of serology and real-time pcr. | 2014 | 24548161 |
| expression of ehrad54, ehrad51, and ehblm proteins during dna repair by homologous recombination in entamoeba histolytica. | entamoeba histolytica, the protozoan responsible for human amoebiasis, exhibits a great genome plasticity that is probably related to homologous recombination events. it contains the rad52 epistasis group genes, including ehrad51 and ehrad54, and the ehblm gene, which are key homologous recombination factors in other organisms. ehrad51 and ehrad54 genes are differentially transcribed in trophozoites when dna double-strand breaks are induced by ultraviolet-c irradiation. moreover, the ehrad51 rec ... | 2014 | 24534563 |
| synthesis of 4'-(2-ferrocenyl)-2,2':6'2''-terpyridine: characterization and antiprotozoal activity of mn(ii), co(ii), ni(ii), cu(ii) and zn(ii) complexes. | a terpyridine ligand fctpy was reacted with divalent metals (cu, co, mn, ni and zn), yielding five complexes of general formula [metal(fctpy)2][pf6]2. the structure of fctpy was determined by single crystal x-ray diffraction studies. the complexes characterized using various spectroscopic techniques suggested an octahedral geometry around the central metal ion. these complexes were screened for their antiamoebic, trypanocidal and antimalarial activities. it was found that, complexes 2 and 3 show ... | 2014 | 24534536 |
| design, synthesis and biological evaluation of 3-[4-(7-chloro-quinolin-4-yl)-piperazin-1-yl]-propionic acid hydrazones as antiprotozoal agents. | n-acylhydrazones derived from 7-chloro-4-piperazin-1-yl-quinoline were synthesized and biologically evaluated for blood-stage of plasmodium falciparum and entamoeba histolytica trophozoites. n-acylhydrazone f12 was found to inhibit the p. falciparum growth as well as its life cycle with good selectivity, which was achieved by inhibiting hematin formation. compound f24 showed better ic50 value than the amoebicidal drug metronidazole. | 2014 | 24530492 |
| the future for vaccine development against entamoeba histolytica. | entamoeba histolytica is the causative agent of amebiasis, one of the top three parasitic causes of mortality worldwide. in the majority of infected individuals, e. histolytica asymptomatically colonizes the large intestine, while in others, the parasite breaches the mucosal epithelial barrier to cause amebic colitis and can disseminate to soft organs to cause abscesses. vaccinations using native and recombinant forms of the parasite gal-lectin have been successful in protecting animals against ... | 2014 | 24504133 |
| entamoeba histolytica-secreted cysteine proteases induce il-8 production in human mast cells via a par2-independent mechanism. | entamoeba histolytica is an extracellular tissue parasite causing colitis and occasional liver abscess in humans. e. histolytica-derived secretory products (sps) contain large amounts of cysteine proteases (cps), one of the important amoebic virulence factors. although tissue-residing mast cells play an important role in the mucosal inflammatory response to this pathogen, it is not known whether the sps induce mast cell activation. in this study, when human mast cells (hmc-1 cells) were stimulat ... | 2014 | 24502918 |
| structure, absolute configuration, and antidiarrheal activity of a thymol derivative from ageratina cylindrica. | the leaves of ageratina cylindrica afforded a thymol derivative that was characterized by physical and spectroscopical methods as (8s)-8,9-epoxy-6-hydroxy-l0-benzoyloxy-7-oxothymol isobutyrate (1). the absolute configuration of 1 was established as 8s by vibrational circular dichroism spectroscopy in combination with density functional theory calculations and by evaluation of the flack and hooft x-ray parameters. compound 1 showed weak antiprotozoal activity against entamoeba histolytica and gia ... | 2014 | 24502360 |