Identification of two neutral metabolites of stigmasterol found in human feces. Bile acids and sterols I62.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Several radioactive estrogens possessing one, two and three hydroxyl groups were injected orally (and in the case of estrone sulfate also intraperitoneally) into adult male rats. The rats were either intact or had ligated or cannulated bile ducts. Two unconjugated estrogen tetrols together represented 21 - 87% of the total metabolites in the intact rat. One of the tetrols was 2-hydroxyestriol (estra-1,3,5(10)-triene-2,3,16alpha,17beta-tetrol); the other may be estra-1,3,5(10)-triene-2,3,6xi,17beta-tetrol but this was not confirmed. It is concluded that poly-hydroxylated estrogens represent a very large proportion of the previously unidentified water-soluble metabolites of the estrogens in the adult male rat.
136 fecal samples, collected from 47 dairy calves on a calf ranch and in a dairy herd in California, were tested for the presence of group A and group B rotaviruses by reverse transcription-polymerase chain reaction (RT-PCR). Samples were collected from each calf at days 1, 7 and 14. Within the 14 day period, 44 calves (94%) were positive for group A rotavirus and an unexpectedly high number of calves (38 calves, 81%) were positive for group B rotavirus. When these samples were examined by polyacrylamide gel electrophoresis (PAGE), rotavirus was found in 21 calves and all of them had group A electropherotype. Among 25 PAGE positive samples from 21 calves, 17 (68%) were of short electropherotype, 4 (28%) were of long electropherotype and 4 (28%) contained both short and long electropherotype rotaviruses. Group B and short and long electropherotype group A rotaviruses were found in both normal and diarrheic calves.
Explore the source record for details and available documents.
Chloroform extracts of fecal material from 4 subjects on normal mixed western diets were fractionated to obtain an acid fraction and a hexane extract containing neutrals and bases. The acid fraction from at least 2 of the donors induced an elevated frequency of chromosomal aberrations and exchanges in Chinese hamster ovary (CHO) cells. Since acid steroids are expected to be present in the acid fraction, 5 bile acids were assayed for clastogenic activity in CHO cells. Ursodeoxycholic acid induced chromosomal aberrations and exchanges, and this effect was enhanced by the addition of a microsomal S9 mix. However, the enhancement is probably due to physical factors rather than to enzymatic activity.
Naturally occurring fecal mutagens, called fecapentaenes, are hypothesized to contribute to large bowel carcinogenesis. To understand health risks it is necessary to relate fecal mutagen concentrations to intestinal pathologies, i.e. colon cancer. However, fast and reliable methods for analysis of stool for fecapentaene levels are not available. This study presents an evaluation of stabilizing effects on synthetic fecapentaene-12 of various antioxidants, indicating tri-ethylamine to give the best results. Furthermore, it describes a fast extraction procedure for human stool and a subsequent HPLC-analysis which produces quantitative data on fecapentaene-12 concentrations within 30 min.
The prevalence and identification of Eimeria spp. in the Louisiana State University ewe flock were determined from 109 fecal samples. Unsporulated oocysts were recovered from 94 of the samples and 1208 oocysts representing ten species of Eimeria were identified: E. ahsata, E. crandallis, E. Faurei, E. granulosa, E. intricata, E. ovina, E. ovinoidalis, E. pallida, E. parava and E. punctata. Eimeria ovinoidalis, which is probably the most pathogenic, was the species common to the most number of samples (59.6%); however, E. granulosa, which is non-pathogenic, was the most numerous species (23.7% of the total identified). The prevalence and identification of oocysts from ewes may be useful to evaluate infection potential when considering control programs, especially for lambs.
Monoclonal antibodies to bovine enteric coronavirus (BEC) were produced. Additionally, polyclonal antibodies were made in rabbits and guinea pigs and extracted from the yolk of immunized hens. The antibodies were characterized by neutralization test, hemagglutination inhibition test, enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Neutralizing antibody titers of polyclonal antisera ranged from 1:1280 to 1:40,000. Only one out of 908 hybridoma colonies tested secreted antibodies with neutralizing activity. By ELISA, polyclonal sera exhibited high background reactions that could be significantly reduced by treatment with kaolin in the case of rabbit sera. Attempts to establish an ELISA for BEC antigen detection based on polyclonal sera failed due to low sensitivity and specificity. Optimal results were achieved when a mixture of two monoclonal antibodies was coated onto microplates for antigen capture, while rabbit hyperimmune serum served as detecting antibodies in an indirect assay. The combination of the two monoclonal antibodies did not increase sensitivity synergistically, but in a compensatory fashion, probably because of epitope differences between BEC field strains.
By using primers based on the sequence of the VP2 gene of canine parovirus (CPV), we established a rapid and specific assay for identification of the virus from fecal specimens based on the polymerase chain reaction (PCR). By use of a pair of primers, a specific 226-bp sequence was amplified by the PCR. All strains of CPV tested gave a specific amplification product by the PCR, while neither porcine parovirus nor host cell did so. The PCR assay can detect fewer particles of CPV than the conventional methods, being able to detect CPV from fecal specimens in a rapid manner, provided that gel filtration of the samples through a spun column was done to remove inhibitory substances from the fecal specimens. These results suggest that the PCR assay can detect the presence of CPV in dogs early enough to prevent secondary infection by CPV in veterinary hospitals.
Explore the source record for details and available documents.
Two simple two-step competitive enzyme-linked immunoassays for human E. coli heat-labile enterotoxin (LTh) employing microtitration plates coated with rabbit anti-LTh antibody (ELISA) or GM1 ganglioside (GM1-ELISA) are described. LTh of the test sample competed with the same toxin coupled with horse-radish peroxidase. ELISA and GM1-ELISA were able to detect, respectively, as low as 5 ng and 6.5 ng TLh/ml and up to 9 and 11 micrograms TLh/ml. Both techniques were applied to the study of 167 infant diarrhoeas; ETEC producing LTh were identified in 17 diarrhoeal stools. When the faeces were diluted in phosphate buffer, only 17.6% (3 stools) and 29% (5 stools) of LTh-positive faeces were identified in ELISA and GM1-ELISA. When the stools were diluted with phenylmethylsulphonyl fluoride (PMSF), a synthetic protease inhibitor, 82% (14 stools) and 88% (15 stools) of LTh-positive stool supernatants were detected. Aprotinin, another protease inhibitor, was without effect and foetal calf serum, horse serum and bovine serum albumin enabled detection of only a low percentage of LTh-positive stools.
Explore the source record for details and available documents.
BACKGROUND: Mounting evidence suggests a relationship between bacterial metabolism of certain dietary and endogenous factors and the development of colorectal cancer. Deoxycholic acid (DCA) is a well studied co-carcinogen and bio-transformation product of 7alpha-dehydroxylating Clostridia. H2S is a cytotoxic metabolite produced primarily by sulfate-reducing bacteria (SRB). The production of methane indicates low levels of active SRB. Lactic acid bacteria (LAB) have received attention recently due to their putative anti-tumor properties. METHOD: Human stool was spiked with pure cultures of bacteria and diluted in several enriched media. Each dilution titer was analyzed for the presence of the organism by PCR and biochemical assays. Duplicate stool aliquots were stored under various conditions for a 1 month period at -20 degrees C to test viability and detection. RESULTS: Growth and enumeration of each spiked organism was confirmed by PCR and biochemical assays. The combination of bead beating and chemical lysis steps produced the greatest DNA yields. PCR assays detected as low as 75 fg target DNA. The ability to detect Methanobrevibacter smithii, and Desulfovibrio vulgaris by either PCR or biochemical assay declined significantly after storage at -20 degrees C for 1 month. CONCLUSIONS: Accurate detection and quantification of each bacterium using the described methods resulted when stool was processed immediately after collection. Storage of some members of the gut flora results in decrease in or loss of viability.
Ezetimibe (Ezetrol) is a novel cholesterol lowering drug which disposition is not fully understood in man. We developed a selective and high-sensitive assay to measure serum concentration-time profiles, renal and fecal elimination of ezetimibe in pharmacokinetic studies. Ezetimibe glucuronide, the major metabolite of ezetimibe was determined by enzymatic degradation to the parent compound. Ezetimibe was measured after extraction with methyl tert-butyl ether using 4-hydroxychalcone as internal standard and liquid chromatography coupled via an APCI interface with tandem mass spectrometry (LC-MS/MS) for detection. The chromatography (column XTerra) MS, C(18), 2.1 mm x 100 mm, particle size 3.5 microm) was done isocratically with acetonitrile/water (60/40, v/v; flow rate 200 microl/min). The MS/MS analysis was performed in the negative ion mode (m/z transition: ezetimibe 408-271, internal standard 223-117). The validation ranges for ezetimibe and total ezetimibe were as follows: serum 0.0001-0.015 microg/ml and 0.001-0.2 microg/ml; urine and fecal homogenate 0.025-10 microg/ml and 0.1-20 mg/ml, respectively. The assay was successfully applied to measure ezetimibe disposition in two subjects genotyped for the hepatic uptake transporter SLCO1B1.
A group-specific PCR-based temperature gradient gel electrophoresis (TGGE) method was developed to study the population composition of genus Bacteroides in human gut. Highly reproducible and well-separated bands in TGGE fingerprints of ten unrelated human fecal samples showed complex and host-specific Bacteroides species composition. Dynamic monitoring over 22 months of samples from one healthy 10-year-old boy indicated a relatively stable population profile of Bacteroides. The species identity of each band in TGGE gel of this boy was also resolved via comigration analysis of sequenced inserts in a Bacteroides group-specific clone library. This work provides a rapid and effective technique for analyzing the species composition of Bacteroides in human gut.
Intra-species analysis of pulsed field gel electrophoresis (PFGE) on human fecal Bifidobacterium longum isolates revealed that a majority of 12 Japanese subjects harbored strains of unique PFGE types or subtypes over a 68-week period, suggesting that "indigenous"Bifidobacterium strains remain stable for a considerable time in each individual intestinal microbiota.
Infection with gastrointestinal nematodes, particularly Haemonchus contortus, is a major constraint to goat production in the southeastern United States. Non-anthelmintic control alternatives are needed due to increasing resistance of these nematodes to available anthelmintics. Two studies were completed in Central Georgia in August 1999, and April-May 2000, using Spanish does naturally infected with Haemonchus contortus, Trichostongylus colubriformis, and Cooperia spp. to evaluate effectiveness of nematode-trapping fungi as a biological control agent. In the first experiment, five levels of Duddingtonia flagrans spores were mixed with a complete diet and fed once daily to the does (three per treatment) in metabolism crates. The treatment concentrations were (1) 5 x 10(5), (2) 2.5 x 10(5), (3) 10(5), and (4) 5 x 10(4) spores per kilogram body weight (BW), and (5) no spores. Fungal spores were fed for the first 7 days of the 14-day trial, and fecal samples were collected daily from individual animals for analysis of fecal egg count and establishment of fecal cultures. Efficacy of the fungus at reducing development of infective larvae (L3) in the fecal cultures was evaluated. The mean reduction in L3 from day 2 of the treatment period until the day after treatment stopped (days 2-8) was 93.6, 80.2, 84.1, and 60.8% for animals given the highest to lowest spore doses, respectively. Within 3-6 days after termination of fungal spore feedings, reduction in L3 development was no longer apparent in any of the treated animals. In a second experiment, effectiveness of 2.5 x 10(5) spores of D. flagrans per kilogram BW fed to does every day, every second day, and every third day was evaluated. Reduction in L3 development by daily feeding was less in the second experiment than in the first experiment. Daily fungal spore feeding provided more consistent larval reduction than intermittant feeding (every second or third day). When fed daily under controlled conditions, D. flagrans was effective in significantly reducing development of L3 and appears to be an effective tool for biocontrol of parasitic nematodes in goats.