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1. 1. An enzyme which catalyses the transamination between γ-hydroxyglutamate and α-ketoglutarate was extracted from rat-liver acetone powder and purified in excess of 15-fold. Fractionation of the enzyme from a separate aspartate transaminase (L-aspartate: 2-oxoglutarate aminotransferase, EC 2.6.1.1) remained incomplete. 2. 2. [2-14C]Pyruvate was incorporated into γ-hydroxy-α-ketoglutarate and γ-hydroxyglutamate in the presence of glyoxylate in rat-liver homogenate. Specific activity values of these three compounds indicated the occurence of the following pathway: Pyruvate + glyoxylate ⇌ γ-hydroxy-α-ketoglutarate ⇌ γ-hydroxyglutamate. 3. 3. A further possible pathway of γ-hydroxy-α-ketoglutarate metabolism leading to malate and of γ-hydroxyglutamate to its decarboxylation product or to L-hydroxyproline were inferred and discussed.

TSUCHIYA, S., KOBAYASHI, Y., YAMAGUCHI, Y., IMAIZUMI, M., MINEGISHI, M., KONNO, T. and TADA, K. Two Non-T/Non-B Leukemia Cell Lines (THP-3-1 and THP-3-2) Established from a Patient at Different Stages of the Disease. Tohoku J. exp. Med., 1983, 140 (4), 443-444 - Two leukemia cell lines of different phenotypic expression were established from a single patient with non-T/non-B acute lymphocytic leukemia (ALL); one (THP-3-1) was derived from the peripheral blood taken on admission before chemotherapy and the other THP-3-2) during the terminal stage. Both THP-3-1 and THP-3-2 cells were positive for terminal deoxynucleotidyl transferase (TdT) and Ia-like antigen but negative for surface immunoglobulins (Ig), nuclear antigen of Epstein-Barr virus (EBNA) and receptors for sheep erythrocytes. However, there was a difference in the expression of common ALL antigen (J5) between the two cell lines. J5+ cells were found in only 5% of THP-3-1 and in 96% of THP-3-2.

The mitochondrial protein content of liver increased, and mitochondria enlarged after prolonged administration of valproic acid (VPA: N-dipropylacetic acid) to rats. The mitochondria showed low specific activities of membrane-bound enzymes, decreased content of cytochrome aa3, and decreased respiration in states 3 and 4. In vitro studies of amino acid incorporation suggested a decrease in protein synthesis in liver mitochondria from VPA-treated rats. Prolonged administration of VPA seems to impair mitochondrial structure and function.