Detergent solubilization, purification, and separation of specificities of HLA antigens from a cultured human lymphoblastoid line, RPMI 4265.

HLA antigens have been purified to homogeneity after detergent solubilization from RPMI 4265, a human lymphoblastoid line. The inhibition of cytotoxicity assay for HLA antigen was modified, using preincubation with bovine serum albumin of antigen samples containing detergent to prevent lysis of target cells by detergent. Solubilization was tested with many types of detergents. A polyethyleneglycol oleyl ether nonionic detergent mixture, Brij 99:Brij 97 (2:1) was selected for solubilization, since it selectively solubilized HLA antigens, had a low absorbance at 280 nm and was uncharded. HLA antigens were then purified by Lens culinaris lectin affinity chromatography and Bio-Gel A-5m filtration. The antigen specifity HLA-A2 was separated from specificities HLA-B7,12 by isoelectric focusing. Purified HLA antigens contained a subunit of Mr=44,000 with NH2-terminal glycine, and a subunit of Mr=12,000, beta2-microglobulin, with NH2-terminal isoleucine.     

Distribution of alloantigens on human Fc receptor-bearing lymphocytes: the presence of B cell alloantigens on sIg-positive but not sIg-negative lymphocytes.

Human peripheral blood lymphocyte subpopulations were analyzed for the presence of B cell alloantigens with a microcytotoxicity assay. B cell alloantigens were found exclusively on sIg-positive lymphocytes and were not present on sIg-negative, Fc receptor-bearing lymphocytes or sIg-negative, Fc receptor-negative T lymphocytes.     

Increased striatal acetylcholine after 14 months cis-flupenthixol treatment in rats suggests functional supersensitivity of dopamine receptors

Rats received continuous administration of cis-flupenthixol (0.8-1.2 mg/kg/day) or trans-flupenthixol (0.9-1.2 mg/kg/day) in drinking water for 14 months. The administration of cis-flupenthixol, but not trans-flupenthixol, caused apparent cerebral dopamine receptor supersensitivity. Thus, animals receiving cis-flupenthixol, but not trans-flupenthixol, showed enhanced apo-morphine-induced stereotyped behaviour. Dopamine concentration in striatum was not altered by drug treatment but striatal HVA and DOPAC concentrations were reduced in animals receiving cis-flupenthixol, but not trans-flupenthixol. No consistent change in Bmax of KD for specific striatal 3H-spiperone binding was observed after 14 months drug intake. However, in cis-flupenthixol treated animals a 40% increase in Bmax was observed following 2 weeks drug withdrawal. Continuous cis-flupenthixol intake increased striatal acetylcholine concentrations; trans-flupenthixol was without effect. This suggests the apparent increase in cerebral dopamine receptor supersensitivity caused by continuous long-term cis-flupenthixol administration is of functional importance in the intact animal.     

Copper metabolism in mottled mouse mutants. Defective placental transfer of 64Cu to foetal brindled (Mobr) mice.

Decreased placental transfer of 64Cu into both Mobr/Y and Mobr/+ foetuses was apparent after its administration to pregnant Mobr/+ mice. The severity of impairment and the degree of retention and accumulation of 64Cu in the placenta was not as great as has been previously observed in the gut of the suckling Mobr/Y mice.     

Chirality of electrons from beta-decay and the left-handed asymmetry of proteins

A simplified mathematical model of the origin of the left-handed asymmetry of proteins in living matter is presented. The model is based on the hypothesis of Vester and Ulbricht that the chirality of (lefthanded) electrons from naturally beta-active elements, e.g.,¹⁴C,⁴⁰K, etc., was the specific source of the asymmetry; it requires for its application data on the interaction of electrons having non-zero chirality with racemic mixtures of amino acids. This interaction is here treated theoretically in an order-of-magnitude calculation. Our analysis yields a very approximate value of the induced steady-state asymmetry in the amino acids at the beginning of protein synthesis and indicates that this asymmetry, though small, may have been suffcient to account for the dominant left-handedness of proteins now observed.