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Biomedical subjects

C Kent

Publications and source records attributed to C Kent.

At least 163 records · Page 9Linked to original sources
PubMed1992

Regulation of CTP:phosphocholine cytidylyltransferase activity and phosphorylation in rat hepatocytes: lack of effect of elevated cAMP levels.

Immunoprecipitation of 32P-labeled CTP:phosphocholine cytidylyltransferase from freshly isolated rat hepatocytes followed by trypsin digestion and two-dimensional peptide mapping revealed multiple phosphorylation sites. Treatment of the hepatocytes with 0.5 mM of the cAMP analog, 8-(4-chlorophenylthio)-adenosine 3':5'-monophosphate or elevation of intracellular cAMP levels by cholera toxin activated the cAMP-dependent protein kinase activity in intact cells. Despite the activation of cAMP-dependent protein kinase no change in the rate of [3H]choline incorporation into phosphatidylcholine was detected. In addition, the activity of cytidylyltransferase in total cell homogenates and its distribution between soluble and particulate fractions remained unchanged. Comparison of peptide maps of 32P-labeled cytidylyltransferase obtained from control and cholera-toxin-treated hepatocytes did not reveal any differences in the phosphorylation state of cytidylyltransferase. Furthermore, only [32P]phosphoserine residues were detected following phosphoamino acid analysis. We conclude that cytidylyltransferase activity is not altered solely by the activation of the cAMP-dependent kinase in fresh hepatocytes.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Ileocolonic anastomosis: a comparison of the patency of stapled versus hand-sewn techniques.

This study compared strength of hand-sewn sutures to that of staples for end-to-end anastomoses of ileocolostomies in 20 mongrel dogs. In ten dogs, the authors used four applications of staples for the anastomoses. In the other ten, they performed single-layer anastomoses using 4-0 polypropylene sutures. Half the dogs were sacrificed on the third postoperative day; half were sacrificed on the fifth postoperative day. Bursting strengths were obtained by infusing air through a catheter inserted into the colon. Results showed the single-layer hand-sewn anastomosis was significantly stronger than the stapled anastomosis. In addition, a histologic comparison of the two closures showed no difference in inflammatory responses.

Anastomosis, Surgical↗
PubMed1991

Regulation of CTP:phosphocholine cytidylyltransferase activity and subcellular location by phosphorylation in Chinese hamster ovary cells. The effect of phospholipase C treatment.

The phosphorylation state of cytidylyltransferase in Chinese hamster ovary (CHO) cells was correlated with its subcellular distribution and activity in vivo. Western blot analysis of soluble and particulate fractions from control and phospholipase C-treated cells revealed slower migrating forms of cytidylyltransferase present only in the soluble fraction of control cells. These were abolished by incubating the soluble fraction at 37 degrees C in the presence of 5 mM Mg2+ but persisted if 135 mM NaF was present in the incubation. CHO cells were labeled with 32Pi, and cytidylyltransferase was immunoprecipitated from soluble and particulate fractions from control and phospholipase C-treated cells. The slower migrating forms of cytidylyltransferase, present in the soluble fraction of control cells, were phosphorylated at multiple sites. Although an equivalent amount of cytidylyltransferase was immunoprecipitated from the particulate fraction of phospholipase C-treated cells, it contained little 32P. Pretreatment of the CHO cells with okadaic acid, an inhibitor of type 1 and 2A phosphatases, prevented the stimulation of cytidylyltransferase in vivo by phospholipase C. These results demonstrate that dephosphorylation of soluble cytidylyltransferase is required for the phospholipase C-mediated translocation of cytidylyltransferase in CHO cells.

Animals↗