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111.
PCR assays were compared with standard microbiological methods for rapid detection of the United States Pharmacopoeia (USP) bacterial indicators in artificially contaminated samples of raw materials and cosmetic/pharmaceutical products. DNA primers containing the specific sequences of the uidA gene of the β-glucuronidase enzyme for Escherichia coli, the membrane lipoprotein gene oprL for Pseudomonas aeruginosa, and the 16S ribosomal gene for Staphylococcus aureus were used for detection in the PCR reaction. Contaminated samples were incubated for 24 h at 35°C. After incubation in broth media with and without 4% Tween 20, samples were streaked on selective growth media. After 5–6 days, all microbial indicators were morphologically and biochemically identified using standard methods while detection and identification by the PCR-based assays was completed within 27–30 h. Rapid PCR detection of E. coli, S. aureus, and P. aeruginosa will allow a faster quality evaluation and release of raw materials and cosmetic/pharmaceutical products sensitive to microbial contamination. Received 21 June 1998/ Accepted in revised form 11 January 1999  相似文献   
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羊支原体性肺炎,是由支原体引起的一类高度接触性传染病,又称羊传染性胸膜肺炎(Infections pleuropneumonia of sheep and goats),临床症状主要表现为高热、咳嗽、消瘦、  相似文献   
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Pediatric liver disease (PLD) is a major cause of severe morbidity and prolonged hospitalizations in children. Stratifying patients in terms of prognosis remains challenging. The limited knowledge about molecular mechanisms causing and accompanying PLD remains the main obstacle in a search for reliable prognostic biomarkers. A systematic search of MEDLINE via PubMed and Embase via OVID was conducted on studies published between August 2007 and August 2017. Molecular markers with a prognostic potential in terms of survival, need for liver transplantation or disease progression/regression were selected. In general, identified studies were single center smaller case-control studies or case series with a low level of evidence and a high risk of bias. Only 23 studies comprising 898 patients could be included, mostly focusing on biliary atresia, non-alcoholic fatty liver disease, viral hepatitis, and LT; and markers related to morphogenesis and fibrosis. Furthermore, molecular markers in metabolic pathways and inflammation shown to be relevant, however requiring further validation. Hence, further biological and clinical studies are needed to gain greater molecular insight into PLD.  相似文献   
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Three different DNA mapping techniques—RFLP, RAPD and AFLP—were used on identical soybean germplasm to compare their ability to identify markers in the development of a genetic linkage map. Polymorphisms present in fourteen different soybean cultivars were demonstrated using all three techniques. AFLP, a novel PCR-based technique, was able to identify multiple polymorphic bands in a denaturing gel using 60 of 64 primer pairs tested. AFLP relies on primers designed in part on sequences for endonuclease restriction sites and on three selective nucleotides. The 60 diagnostic primer pairs tested for AFLP analysis each distinguished on average six polymorphic bands. Using specific primers designed for soybean fromEco RI andMse I restriction site sequences and three selective nucleotides, as many as 12 polymorphic bands per primer could be obtained with AFLP techniques. Only 35% of the RAPD reactions identified a polymorphic band using the same soybean cultivars, and in those positive reactions, typically only one or two polymorphic bands per gel were found. Identification of polymorphic bands using RFLP techniques was the most cumbersome, because Southern blotting and probe hybridization were required. Over 50% of the soybean RFLP probes examined failed to distinguish even a single polymorphic band, and the RFLP probes that did distinguish polymorphic bands seldom identified more than one polymorphic band. We conclude that, among the three techniques tested, AFLP is the most useful.  相似文献   
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The previously identified QTL for oleic acid content observed in an F2 population from the Brassica rapa ssp. oleifera cross Jo4002 × Jo4072 (a high-oleic-acid individual) was mapped more precisely by adding markers to the linkage group which harbours the locus. In addition, the fad2 gene, which is known to encode the 18:1 desaturase in Arabidopsis, was mapped in Brassica, too. The results are consistent with the QTL corresponding to the Arabidopsis fad2 gene. Comparison of the wild-type and high-oleic-acid allele of the locus revealed only one difference in their nucleic acid sequences leading to an amino acid change. This substitution of leucine by proline most likely affects the fold of the protein and thereby activity of the enzyme. Using this base difference, an allele-specific PCR was designed. The allele-specific markers will be very effective in selection for plants with high-oleic-acid content derived from Jo4072 because they are located exactly at the locus and can differentiate between homo- and heterozygotes.  相似文献   
119.
Bilateral asymmetry in the structure of the second metacarpal was examined in relation to functional hand dominance in a large, clinically nonselected, healthy population sample from the Baltimore Longitudinal Study of Aging. Bilateral bone measurements were made from anteroposterior hand radiographs of a total of 992 individuals, 609 males and 383 females, with an age range of 19–94 years. Hand dominance was determined on the basis of personal impression. Total width and medullary width at the midshaft of the second metacarpal were measured to 0.05 mm using a Helios caliper. These two measurements were used to derive cortical thickness, cortical bone area, periosteal (total) area, medullary area, percent cortical area, and the second moment of area in the mediolateral plane. In both right and left-handed individuals, statistically significant side differences were found in the calculated bone areas and the second moment of area, with the dominant hand being larger. Cortical thickness did not show significant side-related differences for either handedness. These results show that functional handedness leads to periosteal and endosteal expansion of the second metacarpal cortex on the dominant side, increasing bone strength without increasing cortical thickness. This is the first time this pattern of asymmetry has been reported in left-handers as well as right-handers. Our results argue for the primacy of environmental (mechanical) effects in determining bilateral asymmetry of limb bone structural properties. © 1994 Wiley-Liss, Inc.  相似文献   
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