M. O. Schultze

Enzyme and Nucleic Acid Content of Thrombocytes from Normal and Thrombocytopenic Calves.

Summary 1. Bovine thrombocyte concentrates contained acid phosphatase, beta-D-glucuronidase, arylsulfatase, aliesterase (active with three fatty acid esters of carbon chain lengths: C2, C12 and C18) and acetyl-cholinesterase but no alkaline phosphatase. Benzoylcholine was not hydrolyzed by thrombocytes. 2. There was no significant difference in these enzyme activities of thrombocytes from normal or thrombocytopenic calves calculated in terms of activity per 1010 thrombocytes. 3. There was no significant quantity of deoxypentosenucleic or pentosenucleic acid in bovine thrombocyte concentrates from either normal or thrombocytopenic calves. 4. Thrombocytes released by hypoplastic bonemarrow could not be differentiated from normal thrombocytes by the tests used.

Nutritional Value of Plant Materials. II. Prevention of Acute Uremia of the Newborn Rat by Vitamin B12

Summary 1. Acute uremia of the newborn rat observed on rations in which a commercial soybean protein and DL-methionine furnish the only source of amino acids can be prevented by subcutaneous administration of 0.05 pg of vitamin B12 shortly after birth.

Failure of DL-batyl alcohol to prevent aplastic anemia in calves.

Summary Feeding of 3/4 or 1/2 lb trichloroethylene-extracted soybean oil meal/day/100 lb to young calves for 10 days induced aplastic anemia and caused death 14-25 days after feeding of the toxic material had ceased. DL-batyl alcohol injected by various routes after feeding of the toxic agent had ceased, but before appearance of clinical symptoms, failed to prevent development of aplastic anemia.

Effect of dietary lipids on the lipids in rats' milk.

Summary Spectrophotometric determinations of polyenoic acids showed that the milk of rats whose diet contained methyl linoleate as the only source of fatty acid contained significant quantities of unconjugated dienoic, trienoic and tetraenoic acids. Feeding of vegetable oils caused a great increase in concentration of unconjugated dienoic acid and, to a smaller extent, an increase of trienoic and tetraenoic acids in milk fat.

Metabolism of Trichloroethylene in the Bovine.

Summary Following the oral administration of 3 to 12 g of trichloroethylene to calves weighing about 100 lb, about 1% of this compound was excreted in the urine as trichloroacetic acid and from 13 to 25% as trichloro-ethanol (free and combined). Only traces of trichloroethylene were excreted in the urine. No trichloroacetaldehyde could be demonstrated in the urine with the method used. Some of the metabolic products of trichloroethylene in the bovine are the same as those produced by man and dogs.

Protective effects of histones against drug-induced alterations of deoxyribonucleic acid in thymus chromatin

Abstract When S -(1,2-dichlorovinyl)- l -cysteine is cleaved by a lyase in vitro , a very reactive alkylating fragment (AF) is produced which can combine with a variety of acceptors, including DNA. Using 35 S as tracer of AF, it was shown that histone, added as such, and particularly in the form of bovine thymus chromatin reacted with AF and greatly decreased the extent to which AF combined with DNA. In contrast to DNA treated directly with AF, DNA which was isolated from AF-treated chromatin retained most of its primer activity for DNA and RNA polymerases and its susceptibility to hydrolysis by pancreatic DNase I. These results illustrate the role which histones and perhaps other nuclear proteins may have in protecting DNA against interaction with various toxic agents. They may also have a bearing on the susceptibility of various cells, tissues and species to the effects of proximate carcinogens and other proximate toxicants formed by metabolic reactions of toxic or therapeutic agents in vivo .

Effect of phenylalanine on toxicity of S-(dichlorovinyl)-L-cysteine in the rat and the calf.

Summary Both enantiomers of phenylalanine when injected intraperitoneally into rats can greatly reduce the toxicity of S-(1,2-dichlorovinyl)-L-cysteine. To be most effective the DCVC and Phe must be administered simultaneously, a delay of one hour in injection of phenylalanine reducing its effectiveness markedly. Administration of L-phenylalanine to calves failed to reduce the toxic effects of S-(dichlorovinyl)-L-cysteine and development of fatal aplastic anemia.

SURVIVAL OF CALVES TREATED WITH AUTOLOGOUS BONE MARROW AFTER EXPOSURE TO LETHAL DOSE OF WHOLE-BODY IRRADIATION

Summary Intravenous injection of homologous bone marrow or of a mixture of fetal liver, spleen and thymus after exposure to a lethal dose of whole-body gamma-radiation failed to protect calves against death from bone marrow damage. Nine of 15 calves treated with autologous bone marrow recovered after a severe hematologic crisis; 8 of these developed normally, showed no apparent signs of late radiation damage, had regular estrous cycles and 7 are now pregnant.

Effect of S-(dichlorovinyl)-L-cysteine on incorporation of precursors into deoxypentose nucleic acid of leukocytes.

Summary 1. When sodium P32-phosphate was injected intravenously into calves, there was an early labeling of leukocyte DNA. 2. DCVC decreased but did not abolish this uptake of P32 when given concurrently with P32 or when calves were pre-treated with DCVC for 2 or 4 days. 3. When normal calf blood was incubated in presence of H3-thymidine, there was a rapid nuclear uptake by mononuclear leukocytes. 4. DCVC did not inhibit incorporation of H3-thymidine in either blood from DCVC-treated calves or in normal blood incubated in presence of DCVC. 5. Abolishment of DNA synthesis in leukocytes or leukopoietic tissue does not appear to be a primary biochemical lesion through which DCVC induces fatal blood dyscrasia in calves.

Regeneration of liver in lysine-deficient, partially hepatectomized rats.

Summary Rats maintained for 2 weeks on a lysine-deficient ration and then partially hepatectomized were able to regenerate their livers in spite of continued consumption of a lysine-deficient diet.