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Specific inhibition of nuclear RNA polymerase II by alpha-amanitin 总被引:75,自引:0,他引:75
T J Lindell F Weinberg P W Morris R G Roeder W J Rutter 《Science (New York, N.Y.)》1970,170(956):447-449
alpha-Amanitin, a toxic substance from the mushroom Amanita phalloides, is a potent inhibitor of DNA-dependent RNA polymerase II (the nucleoplasmic form) from sea urchin, rat liver, and calf thymus. This compound exerts no effect on the activity of polymerase I (nucleolar form) or polymerase III (also nucleoplasmic). The inhibition is due to a specific interaction with polymerase II or with a complex of DNA and polymerase II. 相似文献
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Engineering controls in veterinary oncology: A survey of 148 ACVIM board‐certified oncologists and environmental surveillance in 20 specialty hospitals 下载免费PDF全文
K. Alexander N. Northrup D. Clarke H. Lindell T. Laver 《Veterinary and comparative oncology》2018,16(3):385-391
Engineering controls (EC, facility and equipment barriers between hazards and people) are used to avoid exposure to chemotherapy drugs. In this study, American College of Veterinary Internal Medicine board‐certified veterinary oncologists were surveyed about their use of containment primary EC (C‐PEC) and supplemental EC (closed system transfer devices, CSTD). The survey was completed by 148 (38%) of practicing diplomates. All used EC. Both C‐PEC and CSTD were used at 92% of hospitals; however, US Pharmacopoeial Convention Chapter <800> (USP <800>) standards were met at only 19% of hospitals and oncologists did not know the type of C‐PEC at 18% of hospitals. Next, surface contamination and EC use were assessed with environmental surveillance for carboplatin, cyclophosphamide, doxorubicin, and vincristine in 20 veterinary specialty hospitals using a commercially available kit. No contamination with carboplatin, doxorubicin, or vincristine was detected, however, there was contamination with cyclophosphamide at 4 hospitals. Based on this study, most veterinary oncologists use C‐PEC and CSTD, but few meet USP <800> standards. Current measures appear effective for preventing contamination with IV drugs, but additional measures are needed for oral drugs. 相似文献
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Acht geschlechtsreife Jungsauen wurden ungefähr 24 Stunden nach Eintritt der Brunst geschlachtet und 8 trächtige Jungsauen 30–60 Tage nach der Besamung geschlachtet. Von deren Uteri wurden Uterusstreifen präpariert und im Durchlaufbad eingespannt. Die Motilität der Muskelstreifen war bei den nicht trächtigen Uteri nach 2 Stunden regelmäβig mit 1–2 Kontraktionen pro Minute, während die spontane Motilität des Myometriums bei der Frühträchtigkeit sehr unregelmäβig war und manchmal ganz fehlte. PGF2α und Oxytocin ergaben immer eine Stimulanz der Motilität in den Muskelstreifen bei den nicht trächtigen als auch bei den trächtigen Jungsauen. 相似文献
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Robert Denison Bruce Caldwell Bernard Bormann Lindell Eldred Cynthia Swanberg Steven Anderson 《Water, air, and soil pollution》1977,8(1):21-34
We investigated both the current status of N2 fixation in western Washington forests, and the potential effects of acid rain on this vital process. Even the low concentrations of SO2 presently found in the Northwest are thought to have an adverse effect on N2 fixation by limiting the distribution of the epiphytic N2-fixing lichen, Lobaria pulmonaria, which is found mainly in deciduous forests. A close relative, L. oregana, was found to be the major N2 fixer in old-growth coniferous forests. It fixes less N2 following exposure to H2SO4 of pH 4 or less. A more serious threat to N2 fixation than acid rain is the practice of deliberately suppressing red alder to keep it from competing with Douglas fir. Also, L. oregana is a late successional species and does not develop in forests where short cutting cycles are practiced. 相似文献
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Three newly delivered dairy cows were given prostaglandin F2α during the immediate postpartum period. PGF2α was administered from day 3–13 post partum in doses of 25 mg twice daily. Endogenous release of PGF2α and progesterone was studied in blood plasma during the experimental period. Rectal examination of the uterus was performed every second day in order to establish the end of uterine involution. Uterine involution in the three cows was completed days 16, 23 and 20, respectively. These figures are to be compared with earlier investigations of uterine involution times, which show about 27 days. It was concluded that PGF2α had a positive effect on the uterine muscular tone.Key words: uterine involution, prostaglandin F2α, bovine 相似文献
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Blood plasma concentrations of estrone and progesterone, calcium and inorganic phosphorus were measured in 22 cows (Swedish Red and White Breed) from 4 weeks prepartum up to 6 days post partum. Ten cows with parturient paresis had Ca levels below 6 mg/100 ml. Data from plasma analyses in individual cows were grouped in the following periods: 28–22, 21–15, 14–8, 7–6, 5–4, 3, 2, 1 day(s) before parturition and 1, 2, 3–6 days after parturition. Statistical comparisons of the levels of the hormones and the ratio progesterone/estrone did not reveal any significant differences between the paretic and normal cows at any time period. The results do not support the theories that high systemic levels of estrogens or an imbalance between estrogen and progesterone predispose towards parturient paresis. 相似文献
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