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711.
Two culture systems for maintenance of Day 13-18 conceptus tissue were developed. Harvested culture media were assayed for luteotrophic activity by determining their ability to stimulate progesterone synthesis by dispersed bovine luteal cells. Significant luteotrophic activity was found in 80% of the 31 tissue culture media studied. A series of experiments carried out to determine the nature of the luteotrophic activity indicate that it is a small (Mr less than 10,000), heat-labile, lipid-soluble substance that is adsorbed by dextran-coated charcoal. The nature and activity of this factor, together with its synthesis by the early bovine conceptus, suggest that it may have a significant role in stimulating progesterone synthesis by the corpus luteum during early pregnancy. 相似文献
712.
Hickey William F. Stieber Anna Hogue-Angeletti Ruth Gonatas Jacqueline Gonatas Nicholas K. 《Brain Cell Biology》1983,12(5):751-766
Brain Cell Biology - Cells of the PC-12 rat pheochromocytoma cell line respond to nerve growth factor (NGF) by sprouting neurites and biochemically differentiating into sympathetic ganglion-like... 相似文献
713.
M. Lourdes Velez-Suberbie Stephen A. Morris Kawaljit Kaur John M. Hickey Sangeeta B. Joshi David B. Volkin Daniel G. Bracewell Tarit K. Mukhopadhyay 《Biotechnology progress》2020,36(3):e2966
To meet the challenges of global health, vaccine design and development must be reconsidered to achieve cost of goods as low as 15¢ per dose. A new recombinant protein-based rotavirus vaccine candidate derived from non-replicative viral subunits fused to a P2 tetanus toxoid CD4(+) T cell epitope is currently under clinical development. We have sought to simplify the existing manufacturing process to meet these aims. To this end, we have taken a holistic process development approach to reduce process complexity and costs while producing a product with the required characteristics. We have changed expression system from Escherichia coli to Pichia pastoris, to produce a secreted product, thereby reducing the number of purification steps. However, the presence of proteases poses challenges to product quality. To understand the effect of fermentation parameters on product quality small-scale fermentations were carried out. Media pH and fermentation duration had the greatest impact on the proportion of full-length product. A novel acidic pH pulse strategy was used to minimize proteolysis, and this combined with an early harvest time significantly increased the proportion of full-length material (60–75%). An improved downstream process using a combination of CIEX and AIEX to further reduce proteases, resulted in maintaining product quality (95% yield). 相似文献
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