Biomedical subjects

K Guo

Publications and source records attributed to K Guo.

76 records · Page 5Linked to original sources

PubMed1989

Endotoxin-induced cytokine gene expression in vivo. I. Expression of tumor necrosis factor mRNA in visceral organs under physiologic conditions and during endotoxemia.

Tumor necrosis factor (TNF) mRNA was detected by Northern blotting in whole-organ homogenates of the spleen, liver, kidney, lung, and small bowel in naive and saline-injected control rats, supporting the hypothesis that TNF mRNA is present in vivo in a preformed intracellular pool. TNF mRNA in endotoxin-treated rats as quantitated by densitometry of the ratio of TNF mRNA to actin mRNA in Northern blots was present in increased quantity in the liver, kidney, and lung (1.6-2.9 times over time zero levels) at 15 minutes and increased quantity in the spleen, liver, and kidney (1.3-1.9 times over time zero levels) at 30 minutes. The kinetics of endotoxin-induced TNF gene expression are consistent with the relatively transient peak of serum TNF protein levels reported by previous investigators to occur approximately 1 hour after injection of endotoxin. Because TNF mRNA appeared ubiquitous in the organs of control rats examined and because the endotoxin-induced increase in TNF mRNA was relatively small, endotoxin may induce the expression of the TNF protein in serum not only by increasing TNF mRNA levels but perhaps more importantly by a posttranscriptional mechanism. The presence of a preformed pool of TNF mRNA may teleologically be viewed as a mechanism to increase the rapidity of the host's response to sepsis.

Actins↗

PubMed1989

Plasma lipoprotein metabolism in lean and in fat chickens produced by divergent selection for plasma very low density lipoprotein concentration.

Plasma lipoprotein metabolism was studied in vivo in two lines of chickens produced by selection for high and low plasma very low density lipoprotein (VLDL) concentration. Rates of VLDL secretion were measured by determining the rate of accumulation of triglyceride in the plasma after intravenous injection of anti-lipoprotein lipase antibody. The clearance of VLDL-triglyceride and its uptake into liver and adipose tissue was examined using radioactively labeled VLDL synthesized in vivo. The rate of VLDL secretion was about threefold higher in the high-VLDL line as compared to the leaner, low VLDL-line (6.7 vs 2.1 mumol VLDL triglyceride/h per ml of plasma). The clearance of VLDL from the circulation of the low VLDL line was much faster than that of the high VLDL line (t1/2 of 3.7 and 13.6 min, respectively). The proportion of administered radiolabel taken up by the abdominal fat pad was substantially greater in the fat line than in the lean line (11.9 vs 4.8%, respectively). Lipoprotein lipase activities in leg muscle and heart were consistently greater in the low-VLDL line and beta-hydroxybutyrate concentrations in the plasma of the low-VLDL line were significantly greater than those in the high-VLDL line (0.86 vs 0.48 mumol/ml). The results show that the approximately tenfold difference in plasma VLDL concentration between lines is primarily due to markedly different rates of hepatic VLDL production and that selection has made a major effect on partitioning of VLDL triglyceride between adipose and other tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1988

Biochemical indicators of fatness in meat-type chickens: lack of correlation between lipoprotein lipase activity in post-heparin plasma and body fat.

1. Possible relationships between fatness and lipoprotein lipase activity in adipose tissue and plasma from heparinised birds were examined in 7-week-old male and female broilers. 2. Total lipoprotein lipase activity in abdominal fat was significantly correlated (r = 0.5) with fat pad weight, but there was no correlation between specific activity of the enzyme and fat pad weight. 3. Lipoprotein lipase activity in post-heparin plasma showed no correlation with either abdominal fat or total body fat content. 4. The results indicate that measurements of lipoprotein lipase activity in biopsy samples or in post-heparin plasma are of no value in predicting the fat content of live birds.

Adipose Tissue↗

PubMed1986

Expression of immunoglobulin lambda chains in the laboratory rat.

We immunized a BALB/c mouse with the lambda-bearing rat IgG1 myeloma IR31, fused its spleen cells with the hybridoma parent line P3.X63.Ag8.653, and isolated a monoclonal antibody (G33/11) directed against rat immunoglobulin lambda chains. We used this antibody to classify two existing rat hybridomas as lambda-bearing proteins (D4.37HL.252 and PC61.5), and isolated one new lambda-bearing rat IgM hybridoma, G36/1. All the normal inbred rat sera that were tested contained lambda-bearing Ig as detected by G33/11, at levels ranging from 1.5% to 13% of the total serum Ig, the mean value being 7.9%. This antibody will be valuable for broadening our understanding of the immunogenetics of the rat, and for the characterization of monoclonal antibodies made in this species.

Animals↗