Peroxidase activity in human red cell: a biological model for excited state molecules generation.

The presence of enzymically generated triplet acetone in red cells and energy transfer to eosin, rose bengal and 9,10-dibromoanthracene-2-sulfonate was indicate by: (1) product distribution; (2) K_ET τ_o, similar to the 2-methylpropanal/peroxidase/O₂ system; (3) correlation between hemolysis, oxygen uptake and photon emission; (4) membrane protection by energy acceptors, and (5) by comparison of the 2-methylpropanal/peroxidase/O₂ system with 2-methylpropanal/red cells/membranes/O₂ and 2-methylpropanal/acid extractable protein from red cells membrane/O₂ systems, which have a high peroxidase activity.This is the first report of a biological system producing a photohemolysis effect in the dark.     

Characterization of neutral glycosphingolipids from fetal human brain: evidence for stage-specific expression of the globo, ganglio, and neolacto series in the central nervous system

Neutral glycosphingolipids were isolated from normal human fetal brains, at 22 to 23 weeks gestation. They were identified as monohexosylceramides, lactosylceramide, and glycolipids belonging to the globo (globotriaosylceramide) and ganglio (gangliotriaosylceramide) series. In addition, considerable amounts of neolactotetraosylceramide and III3-alpha-fucosyl-neolactotetraosylceramide were detected. Although neutral glycolipids of the globo, ganglio, and neolacto series have been demonstrated in the brains of cases with some sphingolipidoses, they are not present in appreciable amounts in differentiated normal brain. Therefore, the present and previous observations would imply that the metabolism of these glycolipid series actively occurs in the normal brain at an early stage of differentiation and continues thereafter in the brain in the case of some sphingolipidoses. The diseased brain is most probably accompanied by a disturbance of differentiation.     

Purification and properties of GM2 synthase, UDP-N-acetylgalactosamine: GM3 beta-N-acetylgalactosaminyltransferase from rat liver

A UDP-N-acetylgalactosamine:ganglioside GM3 beta-N-acetylgalactosaminyltransferase which catalyzes the conversion of ganglioside GM3 to GM2 has been purified over 6300-fold from a Triton X-100 extract of rat liver particulate fractions by hydrophobic chromatography and affinity chromatography on GM3-acid-Sepharose. The purified enzyme has two identical subunits of 64,000 daltons. The enzyme has a pH optimum of pH 6.7-6.9 and requires divalent cations such as Mn2+ and Ni2+. In studies on substrate specificity GM3 containing N-acetylneuraminic acid (GM3(NeuAc] and GM3 containing N-glycolylneuraminic acid were both good acceptors for the purified enzyme. The plots of the activity of transferase as a function of GM3(NeuAc) showed sigmoidal relationships. The oligosaccharide of GM3, sialyllactose, was also a good acceptor, which indicates that the preferred acceptor substrate has the possible structure NeuAc alpha 2- or NeuGc alpha 2-3 Gal beta 1-4Glc-OR.     

Spacing and kinship in the Formosan squirrel living in different habitats

Summary Spacing and kinship of the Formosan squirrel, Callosciurus erythraeus thaiwanensis, were studied in two different habitats. One, native habitat in the woods of Kenting, southern Formosa, was rich in available food throughout the year and had several species of predators. The other, a site in Kamakura, central Japan where squirrels had been introduced, had relatively scanty food and few potential predators. 1. Home ranges among males and between sexes overlapped extensively in both habitats. 2. Females occupied exclusive home ranges in Kamakura but had small overlapping home ranges in Ken-ting. 3. Most males disappeared from their natal areas at 1 year old in both habitats (86% in Kamakura and 93% in Ken-ting), but less females disappeared (36% in Kamakura and 35% in Ken-ting). 4. In Kamakura, daughters settled adjacent to the mother or inherited the home range of the mother, but never shared the mother's home range. In Ken-ting, 35% of daughters shared the home range with their mothers. 5. Tolerance among female kin in Ken-ting was probably facilitated by the richness of available food throughout the year, and functioned to reduce predation risk via alarm calling and mobbing.     

Radioimmunoassay for non-enzymatically glycated serum proteins

We have developed a radioimmunoassay (RIA) for nonenzymatically glycated serum proteins. The polyclonal antibodies prepared against reduced glycated human albumin were specific for the glucitollysine residues of serum proteins. Serum proteins from diabetic patients (n = 25) contained 5.3 +/- 2.8 nmoles of glucitollysine/mg protein, compared to 2.0 +/- 0.2 in controls (n = 20). The intra- and inter-assay variables were 3.2-6.2% and 4.4-8.6%, respectively. Results from this assay procedure correlated well with those from the boronate affinity chromatography procedure (r = 0.94; P less than 0.001). The data suggested that diabetic serum proteins contained at least 2.5 times as much immunochemically detectable glucitollysine residures as normal serum proteins after reduction of the proteins with sodium borohydride.     

Antitumor effect of RBS (rice bran saccharide) on ENNG-induced carcinogenesis

We examined whether orally administered RBS (rice bran saccharide), prepared from rice bran by hot water extraction, increases immunocompetence, inhibits gastrointestinal carcinogenesis with N-ethyl-N-nitro-N-nitrosoguanidine (ENNG) or shows an antitumor effect. After the administration of RBS, phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood was enhanced, and the helper/ suppressor T-cell ratio was elevated, and migration activity of peritoneal macrophages was also increased in rats treated continuously with ENNG. ENNG-induced gastrointestinal carcinomas were observed in 43% of those administered RBS (ENNG-RBS) as compared with 88% in the control (ENNG) and 94% in the prednisolone (PRD) group (ENNG-PRD). The 12-month survival rate of rats bearing gastrointestinal cancer was 58% in the ENNG-RBS group as compared with 25% in the ENNG group and 15% in the ENNG-PRD group. RBS prevented the reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of rats with gastrointestinal cancer. Antitumor activities of RBS are thought to be a kind of host mediated action. The growth inhibition ratio of transplantable ENNG-induced cancer in Wistar rats was 42.1% in the RBS and 51.8% in the 5-FU group. Since little is known about the potent antitumor activity of -glucan, it would be interesting to consider the relationship between the structure and the biological activities of polysaccharides.