Analysis of fibrinogen genes in patients with congenital afibrinogenemia

Several cDNA clones coding for A alpha, B beta and gamma chains of fibrinogen have been isolated from a human liver cDNA library. They were selected by differential hybridization with probes raised against fractionated liver mRNA (positive probes) and muscle and albumin mRNA (negative probes), then firmly identified by positive hybridization selection. Three of these clones, encoding A alpha, B beta and gamma fibrinogen chain sequences, were further characterized by restriction mapping and used as probes to characterize fibrinogen mRNAs from adult and fetal liver and fibrinogen genes in normal individuals and two afibrinogenemic patients. The results indicate that there is a single copy of the fibrinogen genes which are present and grossly intact in afibrinogenemic DNA.     

Biochemical changes in a 100 km run: proteins in serum and urine.

Eleven male subjects took part in a 100 km running competition. Alterations in the total plasma protein and in ten individual plasma protein concentrations in blood and urine were measured prior to the run, immediately after and after 1 day of recovery. Five individual proteins showed a 7-10%, and lysozyme a 40%, increase in the plasma after the run. On the contrary, the haptoglobin concentration fell to 40% of its pre-race level. None of these variations were correlated with the plasma volume change. The present data showed a moderate hemolysis, as evidenced by plasma lysozyme and hemoglobin-haptoglobin binding. The urinary excretion of plasma proteins was slightly increased, especially albumin and alpha1-acid-glycoprotein. The renal clearance of plasma proteins revealed that the 100 km run induced a moderate increase of glomerular permeability without any signficant change in the tubular reabsorption process.     

Synthesis and secretion of some plasma proteins by tissue slices of Morris hepatoma 7777 and liver from control and turpentine-injected rats

Slices of Morris hepatoma 7777 or rat liver isolated from control or turpentine-injected rats were incubated for 2 h with 14C-leucine. Radioactivities incorporated into albumin, alpha-fetoprotein, fibrinogen, alpha 1-AP-globulin, haptoglobin and alpha 1-acid glycoprotein were determined after the proteins had been isolated from the incubation medium or tissue homogenate by immunoprecipitation with monospecific antisera. It was found that hepatoma synthesizes fibrinogen, alpha 1-AP-globulin and alpha 1-acid glycoprotein in the amounts comparable to rat liver, whereas formation of albumin and haptoglobin is reduced 5- to 10-fold. Local inflammation elicited by injection of turpentine to tissue donors increased formation of acute-phase protein in liver slices but had no effect on synthesis of these proteins in preparations of Morris hepatoma, although certain ultrastructural changes in the Golgi complex were observed not only in the liver but also in the tumour.     

Influence of chronic inflammation on the level of mRNA for acute-phase reactants in the mouse liver

Systemic injuries provoke a coordinate change in the hepatic synthesis and circulating concentration of plasma proteins. To assess the effect of a transition from acute to chronic inflammation on the expression of the plasma protein genes, the qualitative and quantitative changes of liver mRNA were measured in males of the inbred strain C57BL/6 of Mus musculus during a 14-day period of inflammation. Inflammation was induced and maintained by repeated injections of the irritants, turpentine, lipopolysaccharides, and celite. At various times, total RNA was extracted from the liver. The concentration of specific mRNA was quantitated by cellfree translation and by blot hybridization with cDNA. The mRNA for the increased plasma proteins serum amyloid A, alpha 1-acid glycoprotein, haptoglobin, and alpha-fibrinogen showed essentially the same time course of changes. The concentrations were maximal 24 hr after initiation of inflammation and then declined gradually during the following days. During the progression from acute to chronic inflammation, there was a switch from a predominant expression of the gene for alpha 1-acid glycoprotein-1 to one of alpha 1-acid glycoprotein-2. The prolonged inflammation had an inverse effect on the two major negative acute-phase reactants, albumin and major urinary proteins. The concentration of albumin mRNA was reduced to 50% after 24 hr of inflammation but returned to the control level within 5 days. The mRNA for major urinary proteins, however, were lowered within 2 to 5 days of inflammation to 10 to 20% and were maintained at that level. These results suggest that different regulatory factors, humoral and/or cellular, are involved in controlling the expression of the genes for positive and negative acute-phase plasma proteins during acute and chronic inflammation.