Approaches to plasma fractionation for improved recovery and the development of potentially useful clinical factors.

World-wide use of large amounts of highly purified Factor VIII and Factor IX concentrates has increased steadily over the last decade. The increase has resulted in more effective treatment of patients with haemophilia, especially those patients on home care and 'demand' therapy, those on prophylactic therapy for chronic bleeding or those on maintenance therapy for the suppression of inhibitors. Changing socioeconomic conditions have also contributed to greater use of the concentrates. The trend is putting an increasing strain on conventional methods for collecting and fractionating plasma. These include the donor, the nature of the anticoagulant, methods for purification of the clotting factors, procedures for denaturation and/or separation of viral contaminants and patterns of clinical usage. As a result, it is essential that we upgrade the quantity and quality of plasma collected and utilize the most effective new methods for increasing the yield and purity of the plasma fractions. Of special significance are recently described procedures for heat inactivation and/or separation of viral contaminants from the fractions and the long-term promise of genetically engineered proteins.

Quantitative protein synthetic rates in various tissues of a temperate fish in vivo by the method of phenylalanine swamping.

1. A single high-dose injection of 14C- (or 3H-) phenylalanine was used for measurement of protein synthetic rates in tissues of toadfish, Opsanus tau, in vivo. 2. Average rates at 20 degrees C, as per cent of tissue protein synthesized per day, were as follows: liver, 14; head kidney, 15; gill, 7.7; spleen 5.0; heart, 2.3; testis, 1.4; epaxial and pectoral muscle, 0.20-0.23. Elevated rates in muscle (0.71%/day) were found in fed fish. 3. Temperature dependency (Q10) in the 10-20 degrees C range averaged 6-7 for tissues with high rates of protein turnover, and 3-4 in heart and muscle after two-weeks acclimation.

Liver protein synthesis. Molecular weight distribution of pulse-labeled polypeptide chains in normal and thyroidectomized rats.

Equations are presented for determination of elongation rate in vivo for a heterogenous population of polypeptide chain molecular weights. The distribution of pulse-labeled polypeptide chains in rat liver deoxycholate-soluble protein has been obtained by sodium dodecyl sulfate-gel electrophoresis and used to compute a theoretical curve for determination of synthesis time of a 50000 mol. wt. polypeptide chain (tc50). Values of tc50 for normal and thyro-parathyroidectomized Long-Evans male rats were 1.2 and 1.75 min, respectively, representing protein synthetic rates of about 7.5 and 5.1 mg protein/g liver/h. No difference in the molecular weight profile of liver polypeptide chains on the basis of labeling or Amido-black staining was observed between the two groups. The distributions of radioactivity before and after secretion of labeled plasma protein are compared. The role of protein-synthetic rate in the changing enzyme levels associated with thyroid hormone is discussed.