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Al-Bahry SN Al-Mashani BM Al-Ansari AS Elshafie AE Mahmoud IY 《Asian Pacific journal of tropical medicine》2013,6(9):718-722
ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tcr) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tcr E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment. 相似文献
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目的:通过与组织学的对照研究,探讨MSCT和一种新型的μCT系统对评价恶性脑肿瘤体积的诊断准确性。方法:14只小鼠通过立体定向术植入GFP标记的98F一胶质瘤细胞。植入术后第10天所有小鼠行双倍剂量对比增强μCT和MSCT检查。将2种检查方法测量的肿瘤体积与组织病理学结果进行对照分析。 相似文献
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I. Y. Iourov T. Liehr S. G. Vorsanova A. D. Kolotii Y. B. Yurov 《Chromosome research》2006,14(3):223-229
Molecular cytogenetics offers the unique possibility of investigating numerical and structural chromosomal aberrations in
interphase nuclei of somatic cells. Previous fluorescence in-situ hybridization (FISH) investigations gave hints of numerical chromosomal imbalances in the human brain, present as low-level
mosaicism. However, as precise identification of aneuploidy rates in somatic tissues faces major difficulties due to the limitations
of FISH using whole chromosome painting or centromeric probes, in this study low-level mosaicism in the human brain was addressed
for the first time using microdissection-based multicolour banding (MCB) probe sets. We demonstrated that MCB is suitable
for this application and leads to more reliable results than the use of centromeric probes in parallel on the same samples.
Autosomes and the active X chromosome appear as discrete metaphase chromosome-like structures, while the inactive X chromosome
is condensed in more than 95% of interphase nuclei. The frequency of stochastic aneuploidy was found to be 0.2–0.5% (mean
0.35%) per autosome pair, 2% for the X chromosome in the female brain, and 0.4% in the male brain, giving a cumulative frequency
of aneuploidy of approximately 10% in the adult brain. Moreover, MCB as well as multi-probe FISH using centromeric probes
revealed associated signals in a large proportion of brain cells (10–40%). While co-localized signals could not be discriminated
from numerical chromosome imbalances after FISH using centromeric probes, interphase MCB allows such differentiation. In summary,
MCB is the only approach available at present that provides the possibility of characterizing the chromosomal integrity of
arbitrary interphase cell populations. Thus, cytogenetics is no longer limited in its application to dividing cells, which
is a great step forward for brain research. 相似文献
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