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Notes: Abstract— Synaptosomes from guinea-pig cerebral cortex contain a fetuin: sialyl glyco-protein: glycosyl transferase; evidence is presented which indicates that both a sialyl transferase; evidence is presented which indicates that both a sialyl transferase and endogenous acceptors were located in the synaptosome ‘ghost’ fractions. Following solubilization of synaptosomes with Triton X-100 and the use of fetuin minus NANA as acceptor, 25 per cent of the transferase was recovered after centrifugation and column chromatography on Sephadex G-100 and G-200 with a 64·0-fold purification. The enzyme had a pH optimum of 6·3, required no divalent metal cation for activity, and exhibited high activity with either fetuin minus sialic acid, prothrombin minus sialic acid, Tamm-Horsfall glycoprotein minus sialic acid, or orosomucoid minus sialic acid as acceptor; neither BSM nor PSM minus NANA functioned as an effective acceptor. The fetuin:sialyl transferase using fetuin minus sialic acid and CMP-sialic acid as substrates a and b, respectively, gave the following kinetic constants when using the Cleland bisubstrate model: Ka= 35μM; Kb= 3 μM; Kia, = 25 μM; Kib= 25μM; and V1= 92 pmoles. min−1.mg−1 of protein. The following divalent cations inhibited the reaction: Ba2+ 〉 Hg2+ 〉 Pb2+ 〉 Cu2+.

Notes: Abstract— Four glycoprotein:glycosyl transferases (a fetuin:N-acetylglucosaminyl transferase; a bovine submaxillary mucin: N-acetylgalactosaminyl transferase; a collagen: glucosyl transferase and an orosomucoid: galactosyl transferase) were purified 34-, 45-, 37- and 47-fold, respectively, from synaptosomes prepared from guinea pig cerebral cortex. Purifications were achieved by centrifugation and by column chromatography on Sephadex G-100 and G-150 of 0, 1% (w/v) Triton X-100 extractsof the purified cerebral cortical synaptosomes. The enzymes were separated from endogenous acceptors and were highly specific for specific macromolecular acceptors; small molecules were ineffective as acceptors. The fetuin: N-acetylglucosaminyl transferase functioned only with fetuin minus N-acetylneuraminic acid, galactose and N-acetylglucosamine; the bovine submaxillary mucin: N- acetylgalactosaminyl transferase with bovine submaxillary much minus N-acetylneuraminic acid and N-acetylgalactosamine; the collagen: glucosyl transferase with collagen minus glucose; and the orosomucoid: galactosyl transferase with either orosomucoid minus N-acetylneuraminic acid and galactose or fetuin minus N-acetylneuraminic acid and galactose. Each transferase required a specific (XDP)-monosaccharide for transfer. The transferases were entirely dependent on either Mn2+ or Mg2+ for activation and Fe2+ and Hg2+ inhibited each of the four enzymes. The optimum pH's for the enzymes were: for fetuin: N-acetylglucosaminyl transferase, 7, 4–8.0; for bovine submaxillary mucin: N-acetylgalactosaminyl transferase, 7, 7; for collagen: glucosyl transferase, 7, 7 and for orosomucoid: galactosyl transferase, 6, 6. The enzymes were distributed subsynaptosomally primarily in the synaptosomal plasma membrane and in the mitochondria of the synaptosome. The respective values for Km (μM) and Vmex (pmoles/h/mg of protein) for the transferases were: fetuin: N-acetylglucosaminyl transferase, 12 and 143; for bovine submaxillary mucin: N-acetylgalactosaminyl transferase, 25 and 166; for collagen: glucosyl transferase, 4 and 10 and for orosomucoid:galactosyl transferase, 8 and 111.

Notes: Summary Increasingly, decisions to withhold treatment for the terminally ill have received considerable attention in medical, ethical, legal and lay publications. Few studies, however, have examined in detail the beliefs of health professionals about euthanasia, and more importantly, the frequency with which euthanasia occurs. A questionnaire was administered to 190 health care professionals (three-fourths of whom were affiliated with long term health care facilities) to examine these two questions. With regard to passive euthanasia, 83% of the respondents had heard of such cases, 56% had participated, 37% had given the permission for it to occur, and 17% had withheld life support system. With respect to active euthanasia, results were as follows: hearsay, 44%; participation, 21%; permission, 37%; and direct action, 20%. This study supports the need for health care professionals to become more active in the development of broad professional and individual institutional ethical guidelines in the care of the terminally ill.

Notes: Abstract A synaptosomal plasma membrane fraction and its junctional and nonjunctional subfractions were isolated and analyzed for glycoprotein galactosyltransferase activity. The nonjunctional components fraction had the highest specific activity in the presence of exogenous acceptor, suggesting an enrichment of enzyme in this fraction. The synaptic junctional complex fraction had the highest specific activity in the absence of added acceptor, suggesting that there is a relative enrichment of endogenous acceptors for this galactosyltransferase within the synaptic junctional complex.