Four sublines of Chinese hamster ovary (CHO) cells were selected or cloned on a 10% fetal calf serum supplemented MEM-alpha medium. Three of them were monolayer cultures and could proliferate by 2000 ...times a week (mu = 1.1 d 1) in T-flasks. The other subline, S1, could grow in suspension even in static T-flask cultures. The stability in chromosome number of these cell lines was investigated. By evaluating the kinetic growth parameters, i.e. the specific rates of growth, glucose consumption and lactic acid production, and the yields of cells and lactic acid from glucose, the S1 cells were considered to be the most suitable subline for the bioreactor suspension culture. The S1 cells reached the greatest maximum of cell concentration among all cell lines tested because of their efficient glucose utilization. Observed nutrient limitations in the S1 cell culture was overcome by modification of the medium composition, that is addition of 10 mg l-1 hypoxanthine, 1 mg l-1 FeSO4.7H2O, and 0.1 mg l-1 sodium putrescine, elimination of glutamine, supplementation of 6 mM asparagine and double amount of isoleucine, leucine, methionine and vitamins other than ascorbic acid, cyanocobalamin and biotin, increase of NaHCO3 concentration from 26 to 40 mM, and finally decrease of NaCl concentration from 122 to 100 mM. With this modified medium, 7.2 X 10(6) ml-1 of the maximum cell concentration was observed in a glucose fed-batch culture, the cell concentration which was twice as much as in batch cultures with the original medium.
Coronavirus disease 2019 is associated with a significant venous thromboembolic risk. Phlegmasia cerulean dolens is a severe form of deep vein thrombosis that can lead to acute limb ischemia. In this ...report, we present a 58-year-old woman who developed a delayed-onset left lower extremity phlegmasia cerulean dolens 8 weeks after coronavirus disease 2019 onset that led to compartment syndrome and acute limb ischemia from external compression of the arterial vasculature from edematous muscle. The patient received an emergent minimally invasive percutaneous mechanical thrombectomy and four-compartment fasciotomy, resulting in adequate perfusion and ultimately made a full recovery.
CHO SSF3 cells grow as a suspension culture in unmodified commercial medium with only low-molecular weight ingredients. Continuous serum-free culture unexpectedly induced expression of a low ...dihydrofolate reductase activity in the originally
dhfr
−
CHO cells. Nevertheless, it was possible with methotrexate to induce amplification of a gene coding for the hybrid plasminogen activator K2tu-PA cotransfected with a
dhfr gene. Expression of K2tu-PA expression was proportionally increased to that of
dhfr, which was measured with fluorescent methotrexate. Because no serum proteases were present, secreted K2tu-PA was not converted to the enzymatically active form, but was exclusively recovered in proenzyme form.
Evaluation of an intensive community health project by three medical school classes (n=240) found the project was rated more favorably (1) with each succeeding class, (2) by students planning to ...enter primary care specialties, and (3) by students who invested more time in the project. (Author/DB)
To meet the informational needs of health care practitioners and trainees in a four-county rural area of northwestern North Carolina, the eleven-member UNIFOUR Consortium was founded as a two-year ...experimental project from 1978 to 1980. The consortium has several unique features: (1) it is an organization of institutions, not libraries; (2) it employs its own professional librarian who manages a central library, coordinates consortium programs, and makes regular circuit visits to all affiliated institutions; (3) the central library, where the circuit is based, is a developing community hospital library, not an established academic medical center library; and (4) it is ultimately tied to the Northwest Area Health Education Center and that organization's emerging learning resources network, which includes the Bowman Gray School of Medicine, Library, two other subregional libraries, and the libraries of all member institutions. At the end of the experimental period in 1980, member institutions voted unanimously to continue the program and assume their share of the costs.
A process was developed to produce recombinant human renin for X-ray analysis and enzyme inhibition studies. An expression vector containing a human prorenin cDNA and expressing a mouse dihydrofolate ...reductase selection marker was transfected into dhfr-minus Chinese hamster ovary cells. After selection of cell strains with an increased gene copy number with methotrexate, cultures of the recombinant cells were scaled-up in serum-free media. Major improvements in cellular productivity were achieved by using continuous suspension cultures with cell recycling instead of an adherent culture system or batch-mode suspension cultures. The recombinant zymogen prorenin was purified and preparatively activated with trypsin. Enzymatic properties of the recombinant active renin are described.
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