Presence of tetrataenite grains has been recently confirmed in Yamato 791717 carbonaceous (CO3) chondrite. The observed coexistence of tetrataenite fine grains with more abundant magnetite and kamacite in this CO3 chondrite suggests that the tetrataenite grains were directly formed by a coalescence process of Fe and Ni fine particle smokes in the solar nebula.
Accelerator mass spectrometry (AMS) was applied for 26Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26Al as a tracer. When 26Al was intraperitoneally injected into rats, a considerable amount of 26Al was incorporated into the cerebrum after 5-35 days of the injection.
A time-of-flight neutron diffraction experiment was undertaken on a powder sample of orthorhombic ZrO2 synthesized at 600°C and 6GPa for 30min. The Rietveld analysis for the diffraction data shows that the space group of this phase is Pbca. The refined lattice parameters are a0=1.00861, b0=0.52615, and c0=0.50910nm.
A sterol glucoside was detected in both myxoamoeboid and plasmodial stages of mating-less mutant, Colonia strain of Physarum polycephalum. The isolated substance was characterized and identified as poriferasterol mono-glucoside, which was recently detected in the plasmodia but not in the myxoamoebae of wild-type Physarum polycephalum.1) The endogenous activity of UDP-glucose: poriferasterol glucosyltransferase, which transfers glucose moiety from sugar nucleotide to poriferasterol and synthesizes poriferasterol monoglucoside, was found in both myxoamoebae and plasmodia of Colonia strain. This enzyme as well as poriferasterol monoglucoside was detected in the wild-type plasmodia but not in the wild-type myxoamoebae. In wild-type Physarum, the enzyme was expressed in the process of differentiation from myxoamoebae to plasmodia.2) To clarify the biological roles of poriferasterol monoglucoside in the membrane function, comparative studies of some physiological characteristics were performed. The mutant myxoamoebae showed 5-times higher uptake of D-glucose than wild-type myxoamoebae. Colonia myxoamoebae could grow in the glucose-based nutrient medium, but in this medium, wild-type myxoamoebae could hardly survive.
Twenty-two kDa protein specifically decreased in slow soleus muscle atrophy after 2-week hindlimb suspension (HS) of rats. This protein is abundant in soleus muscle but less in fast plantaris muscle. We purified this protein, determined the partial amino acid sequence using its proteolytic fragment, and found that the 22-kDa protein was a α-crystallin B chain with a 95% homology to bovine αB-crystallin. Further we demonstrated that αB-crystallin did not decrease in passively stretched slow muscle even under HS, and did markedly increase in denervated and stretched fast muscle under HS. These results suggest that the expression of αB-crystallin is dynamically related to the muscle plasticity.
An antibiotic, tautomycin induced bled formation and protein phosphorylation of K562 cells as do the protein phosphatase inhibitors, okadaic acid and dinophysistoxin-1. Tautomycin inhibited the specific binding of [3H]okadaic acid to protein phosphatases. Furthermore, tautomycin inhibited the protein phosphatases isolated from mouse brain. However, tautomycin did not activate the protein kinase C. These results indicate that tautomycin induces bled formation through inhibition of protein phosphatases.
Rotary shadowed image of α-connectin (titin 1; TI), mother molecule of the muscle elastic filament, was a long thin rod, approximately 1μm long and 3-4nm wide, with a globular head at one end. β-Connectin (titin 2; TII), the proteolytic product of α-connectin, was also a long rod, about 0.85μm long and 3-4nm wide without the head. It appeared that both α-and β-connectin rods consisted of two laterally associated stands, approximately 1.5nm wide.
cDNA and genomic sequences coding for human protective protein/carboxypeptidase were isolated and characterized. The cDNA sequence was identical with that reported by Galjart et al. (Cell 54: 755, 1988). Two clones hybridizing cDNA were isolated from the human chromosome 20 specific bacteriophage library, comprising the first 5 exons and the next 3 exons, respectively. The exon-intron organization was determined for these clones. Molecular analysis of Japanese adult-form galactosialidosis patients revealed a common gene rearrangement: an A-to-G base substitution at the position 3 by downstream of exon 7, resulting in skipping of this exon in mRNA. All five cases in this study were found to be homozygous for this mutation. We conclude that this is a common gene mutation among the Japanese galactosialidosis patients of late onset (Japanese type).