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51.
D T Brandau P Ray A S Stern R V Lewis 《International journal of peptide and protein research》1985,25(3):238-241
We have isolated a previously unknown peptide and its precursor from bovine adrenal medullary chromaffin granules. The peptide sequence is Leu-Pro-Val-Asn-Ser-Pro-Met-Asn-Lys-Gly-Asn-Glu-Val-Met-Lys. The peptide is cleaved from the precursor at a Lys site. The sequence shows no homology to any known protein in the largest sequence data bank available. 相似文献
52.
STATUS OF STUDIES ON FOSSIL MARINE MAMMALS 总被引:4,自引:0,他引:4
53.
Giuseppe Colacicco Mukul K. Basu Apurba K. Ray Murray Wittner Robert M. Rosenbaum 《Prostaglandins & other lipid mediators》1977,14(2):283-294
Transformed cells from human lung carcinoma (Line A549), resembling type II pneumocytes, were cultured in monolayer at 37°C and incubated for five hours with 3H-choline and 14C-palmitate in the presence of various concentrations of prostaglandins (PGs) E2 and F2α. In the control (no PG) the level of % palmitate incorporation was 13.5 × as high as that of choline, after taking isotope dilution into account. Between the concentrations studied, 0.1 and 10 μM, both prostaglandins stimulated markedly the incorporation of both precursors, though choline up to 3 × better than palmitate. This was indicated by a change in the palmitate/choline incorporation ratio from 13.5 to as low as 4.2. At the lowest PG concentration, 0.1 μM, PGE2 was much more effective than PGF2α in stimulating the incorporation of both precursors. 相似文献
54.
55.
Carrington Stone Cobbs Keith Ray Shelton 《Archives of biochemistry and biophysics》1978,189(2):323-335
The three predominant polypeptides of the insoluble proteinaceous fraction from the HeLa cell nucleus polymerize in vitro upon oxidation of intrinsic sulfhydryl groups. The ease and specificity of this reaction indicate that these polypeptides exist as ordered oligomers in vivo. The comparable insoluble fraction from the rat liver nucleus also contains three predominant polypeptides of the same molecular weights, 65,000 71,000, and 75,000. The insoluble protein of the avian erythrocyte nuclear envelope consists principally of the 71,000- and the 75,000-dalton polypeptides. Indeed, in the avian erythrocyte nucleus these are the predominant polypeptides of the entire nucleus (Shelton, K., Cobbs, C., Povlishock, J. and Burkat, R., 1976, Arch. Biochem. Biophys.174, 177). Further, these avian polypeptides each form homogeneous covalently linked oligomers upon sulfhydryl oxidation (Cochran, D., Cobbs, C. and Shelton, K., 1977, J. Cell Biol.75, 151a). The insolubility, oligomeric disposition, and relative prominence of these polypeptides in a wide variety of cells indicate a fundamental structural role in the nucleus. Morphological features which may reflect this structural or skeletal role could be the nuclear envelope, the fibrous lamina, or perhaps an intrachromatinic matrix. The metabolism of the oligomeric polypeptides has been investigated in HeLa cells. Turnover of the HeLa insoluble nuclear protein is similar to that of the histones which are known to be stable proteins. The insoluble protein, including the oligomeric polypeptides, is synthesized in G1, S, and G2 phases of the cell cycle. This metabolic behavior indicates that the oligomeric polypeptides are reutilized in successive cell cycles and that synthesis accompanies nuclear and cellular expansion rather than deoxyribonucleohistone synthesis. This suggests that neither degradation nor selective synthesis of oligomeric polypeptides at a particular phase of the cell cycle are responsible for the breakdown and reformation of the interphase cell morphological features that occur during mitosis. 相似文献
56.
Hannes Hentze Poh Loong Soong Siew Tein Wang Blaine W. Phillips Thomas C. Putti N. Ray Dunn 《Stem cell research》2009,2(3):198-210
Transplantation of human embryonic stem cells (hESC) into immune-deficient mice leads to the formation of differentiated tumors comprising all three germ layers, resembling spontaneous human teratomas. Teratoma assays are considered the gold standard for demonstrating differentiation potential of pluripotent hESC and hold promise as a standard for assessing safety among hESC-derived cell populations intended for therapeutic applications. We tested the potency of teratoma formation in seven anatomical transplantation locations (kidney capsule, muscle, subcutaneous space, peritoneal cavity, testis, liver, epididymal fat pad) in SCID mice with and without addition of Matrigel, and found that intramuscular teratoma formation was the most experimentally convenient, reproducible, and quantifiable. In the same experimental setting, we compared undifferentiated hESC and differentiated populations enriched for either beating cardiomyocytes or definitive endoderm derivatives (insulin-secreting beta cells), and showed that all cell preparations rapidly formed teratomas with varying percentages of mesoderm, ectoderm, and endoderm. In limiting dilution experiments, we found that as little as two hESC colonies spiked into feeder fibroblasts produced a teratoma, while a more rigorous single-cell titration achieved a detection limit of 1/4000. In summary, we established core parameters essential for facilitating safety profiling of hESC-derived products for future therapeutic applications. 相似文献
57.
Monocentric chromosomes of Vicia faba (2n=12) and polycentric chromosomes of Luzula purpurea (2n=6) and L. multiflora (2n=36) were studied by the C-banding technique. C-positive regions exhibited a restricted distribution in V. faba nuclei and were located near the centromeres of the chromosomes. Each chromosome had both a characteristic number and distribution of C-positive regions permitting homologue identification. L. purpurea and L. multiflora C-bands were much more numerous than those of V. faba and were widely distributed throughout both nuclei and chromosomes. Three distinct constitutive heterochromatin distribution patterns were present in L. purpurea metaphase chromosomes permitting homologous chromosome identification. One of three C-band distribution patterns was also evident in L. multiflora chromosomes. 相似文献
58.
59.
In randomized clinical trials, the log-rank test and Cox proportional hazards model are the gold standard in survival data analyses. While the log-rank tes 相似文献
60.
Hood Glen Ray Papuga Shirley A. Socrates Connor Rankin Kennadi Hwang Kyotaek 《Plant and Soil》2021,466(1-2):569-580
Plant and Soil - Tussock microhabitat is a universal phenomenon in wetlands, where soil and plant properties differ from their surrounding lawns. This study aims to investigate the differences of... 相似文献