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排序方式: 共有202条查询结果,搜索用时 234 毫秒
141.
Gades NM Ohash A Mills LD Rowley MA Predmore KS Marler RJ Couch FJ 《Comparative medicine》2008,58(3):271-275
Mice in a colony used for pancreatic cancer research and maintained in a barrier animal facility presented with vulvar masses. A census and examination of all colony animals was conducted on 17 February 2006; line, gender, and mass location were recorded; a slide caliper was used to measure the width, length, and height of each mass; and the volume of each mass was calculated. Progeny female mice from crossbreeding of the B6.FVB-Tg(Ipf1-cre)1Tuv and B6;129-Kras2tm4Tyj (KRAS(G12D/+)) strains presented with external vulvar and periauricular papillomas. The papillomas were present in 41.2% of all female crossbred mice and ranged in size from 8 to 36 mm3. Age of mice and tumor size were not correlated. Compared with the B6.FVB-Tg(Ipf1-cre)1Tuv line, the crossbred female mice were more likely to have a vulvar mass, with an odds ratio of 29.3, 95% confidence interval (1.5, 563.9) and a positive predictive value of 42.9%. Diagnostic evaluation, including electron microscopy, light microscopy, serology, and bacteriology, did not reveal a viral or other infectious etiology. Therefore, we speculate that interaction between the genetic background of the mice and the introduced Kras oncogene may be responsible for these papillomas. 相似文献
142.
Regulation of Polyglutamic Acid Synthesis by Glutamate in Bacillus licheniformis and Bacillus subtilis 总被引:2,自引:0,他引:2
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The synthesis of polyglutamic acid (PGA) was repressed by exogenous glutamate in strains of Bacillus licheniformis but not in strains of Bacillus subtilis, indicating a clear difference in the regulation of synthesis of capsular slime in these two species. Although extracellular γ-glutamyltranspeptidase (GGT) activity was always present in PGA-producing cultures of B. licheniformis under various growth conditions, there was no correlation between the quantity of PGA and enzyme activity. Moreover, the synthesis of PGA in the absence of detectable GGT activity in B. subtilis S317 indicated that this enzyme was not involved in PGA biosynthesis in this bacterium. Glutamate repression of PGA biosynthesis may offer a simple means of preventing unwanted slime production in industrial fermentations using B. licheniformis. 相似文献
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Paweł Zagrodzki Fergus Nicol John R. Arthur Marian Słowiaczek Stanisław Walas Halina Mrowiec Renata Wietecha-Posłuszny 《Biological trace element research》2010,134(1):25-40
This study was performed to investigate selenoenzyme activities and trace element concentrations in thyroid tissues, with
reference to other parameters routinely used to characterize thyroid function. This was to reveal relevant parameters as possible
additional markers of tumor grade, clinical course, and prognosis of thyroid disorders. The tissue samples were obtained during
surgical treatment (total or near total thyroidectomy) of 122 patients with different types of thyroid tumor. For most of
the investigated parameters in different groups of patients, we did not find statistically significant differences. In the
majority of cases, thyroid benign or malignant tumors were not accompanied by significant derangement of the gland selenoenzymes
and of either intrathyroidal or plasma concentration of selenium. Nevertheless, types I and II iodothyronine deiodinases were
the most promising (among selenoenzymes) targets for diagnoses and possibly therapy of thyroid tumors. Higher activities of
both enzymes in cases with Graves’ disease, as compared with other thyroid lesions, suggest their involvement in the pathogenesis
of this condition. Patients with struna nodosa had higher levels of thyroid Zn, Cu, and Pb as compared with papillary carcinoma
subjects and also a higher level of Cu than follicular carcinoma cases. The above diagnostics may play a similar role to some
of the general thyroid function indices, TSH, anti-TG, anti-TPO, and calcitonin, which can partially distinguish between various
thyroid tumors. In conclusion, some of selenium status markers, when accompanied with general parameters, and trace elements
can serve as factors with pathophysiologic relevance and be helpful in the identification of malignant disease. Multivariate
statistical methods should be employed to tackle a broad array of thyroid tumor diagnostic data in a short time. Partial least
squares model and other pattern recognition methods seem to be the most appropriate methods for that task. The miniaturization
of all the steps of complex analytical procedure should be developed in a way to allow its completion as sensitive, robust,
and efficient for use of the small quantity of material provided by fine-needle biopsy. 相似文献
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148.
The molecular action of the novel insecticide, Pyridalyl 总被引:1,自引:0,他引:1
Powell GF Ward DA Prescott MC Spiller DG White MR Turner PC Earley FG Phillips J Rees HH 《Insect biochemistry and molecular biology》2011,41(7):459-469
Pyridalyl is a recently discovered insecticide that exhibits high insecticidal activity against Lepidoptera and Thysanoptera. Pyridalyl action requires cytochrome P450 activity, possibly for production of a bioactive derivative, Pyridalyl metabolism being prevented by general P450 inhibitors. Apoptosis is apparently not involved in the cytotoxicity. Continuous culture of Spodoptera frugiperda Sf21 cells in sub-lethal doses of Pyridalyl, results in a Pyridalyl-resistant cell line. Probing the molecular action of Pyridalyl by comparison of the proteomes of Pyridalyl-resistant and -susceptible cell lines, revealed differential expression of a number of proteins, including the up-regulation of thiol peroxiredoxin (TPx), in the resistant cells. Treatment of Bombyx mori larvae with Pyridalyl, followed by comparison of the midgut microsomal sub-proteome, revealed the up-regulation of three proteasome subunits. Such subunits, together with Hsp70 stress proteins, glyceraldehyde 3-phosphate dehydrogenases (GAPDHs) and thiol peroxiredoxin (TPx) were also up-regulated in the whole proteome of B. mori BM36 cells following treatment with the insecticide. The foregoing results lead to the hypothesis that cytochrome P450 action leads to an active Pyridalyl metabolite, which results in production of reactive oxygen species (ROS), that leads to damage to cellular macromolecules (e.g., proteins) and enhanced proteasome activity leads to increased protein degradation and necrotic cell death. 相似文献
149.
Piel A. K. Crunchant A. Knot I. E. Chalmers C. Fergus P. Mulero-Pázmány M. Wich S. A. 《International journal of primatology》2022,43(1):133-167
International Journal of Primatology - Observing and quantifying primate behavior in the wild is challenging. Human presence affects primate behavior and habituation of new, especially terrestrial,... 相似文献
150.
Adam S Arterbery Daniel J Fergus Elizabeth A Fogarty John Mayberry David L Deitcher W Lee Kraus Andrew H Bass 《BMC evolutionary biology》2011,11(1):14