Cc Of Medium Research Articles

Galactose and glucose metabolism in galactokinase deficient, galactose‐1‐P‐uridyl transferase deficient and normal human fibroblasts

Despite the genetic interruption of the Leloir pathway both galactosemic patients and galactosemic fibroblasts can convert galactose to CO2 and TCA precipitable products, although at less than the normal rate. These observations stimulated investigations into the identity of the alternative metabolic routes which allows for galactose metabolism in the absence of in vitro galactose-1-P-uridyl transferase. Four lines of galactosemic cells, each without detectable gal-transferase, produced 14CO2 from [1-14C]-galactose (0.094 mumoles in 20 cc of medium) at approximately 39% +/- 16% the rate of transferase positive cells over a 48-hour period. However, galactokinase deficient fibroblasts produced 14CO2 and TCA precipitable products from [1-14C]-galactose or [U-14C]-galactose at only 3% to 9% the rate of normal fibroblasts. Therefore it seems likely that gal-transferase deficient fibroblasts must first synthesize galactose-1-P for further metabolism of galactose.

Estrogen stimulation of prolactin production by rat adenohypophysis in vitro.

Explants from anterior pituitaries of mature female rats were cultured by a watch glass technique for 6 or 7 days in synthetic medium “199.” The medium was assayed for prolactin activity by the sensitive intradermal pigeon crop method. It was demonstrated that the pituitary explants were capable of synthesizing and releasing almost as much prolactin each day as they contained at the beginning of culture. An average of 0.8 Reece-Turner prolactin units (approximately 0.1 iu) was produced per pituitary each day in cultures maintained in 95% O2-5% CO2 atmosphere. Medium incubated without any tissue had no prolactin activity. Considerable prolactin activity was still detected in the medium at the end of a 3-week culture, showing that the explants continued to produce prolactin for the entire period. Histological examination of the pituitary explants at the end of the culture period revealed that the cells were in a viable state. In 10 trials, addition of 0.5 μg estradiol per cc of medium significantly increase...

Propagation of Theiler's GD-VII Mouse Virus in Tissue Culture

Summary and Conclusions(1) Theiler's GD-VII virus has been propagated for 20 passages (transfers) in cultures of chopped mouse embryo brain suspended in ox serum ultranltrate and Simms' X7 solution. After an initial series of culture passages, the cell-free culture fluid killed mice in dilutions as high as 1:1,000,000 when 0.03 cc was injected intracerebrally. Eventually, the same results were achieved when the ox serum ultranltrate was replaced by heated rabbit serum. (2) The virus multiplied more abundantly at 35°C than at 37.5°C; and, the yield was higher in 125 cc Erlenmeyer flasks containing 3 cc of medium than in 50 cc flasks containing 4 cc of medium. (3) No increase in virus output was ever obtained by inoculating subcultures with ground material; nor did grinding the culture tissues improve the mouse titrations. Also, no real advantage was gained by subjecting the cultures to continuous gassing with mixtures of O2 CO2 and N2. (4) The concentration of virus in the culture medium was higher after 2...

Effect of Nicotinic Acid, Its Isomers and Related Compounds upon Nutrition of Staphylococcus aureus.

Neither of the 2 isomers of nicotinic acid was able to replace nicotinic acid itself in the nutrition of S. aureus. when tested in concentrations up to 20 gamma per 10 cc of medium. Reduction in the activity of nicotinic amide was brought about by introduction of an ethyl group. Complete loss of activity was evident by introduction of 2 ethyl groups into nicotinic amide. Pyridine 2-3:dicarboxylic acid was inactive as a factor in the growth of S. aureus.