Gap Junctions Mediate Glucose Transport Between GLUT1-Positive and -Negative Cells in the Spiral Limbus of the Rat Cochlea

To elucidate the role of the spiral limbus in glucose transport in the cochlea, we analyzed the expression and localization of GLUT1, connexin26, connexin30, and occludin in the spiral limbus of the rat cochlea. GLUT1 and occludin were detected in blood vessels. GLUT1, connexin26, connexin30, and occludin were also expressed in fibrocytes just basal to the supralimbal lining cells. Connexin26 and connexin30 were present among not only these GLUT1-positive fibrocytes but also GLUT1-negative fibrocytes. In vivo glucose imaging using 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-6-deoxyglucose (6-NBDG, MW 342) together with Evans Blue Albumin (EBA, MW 68,000) showed that 6-NBDG was rapidly distributed throughout the spiral limbus, whereas EBA was localized only in the vessels. Moreover, the gap junctional uncoupler heptanol inhibited the distribution of 6-NBDG. These findings suggest that gap junctions play an important role in glucose transport in the spiral limbus, i.e., that gap junctions mediate glucose transport from GLUT1-positive fibrocytes to GLUT1-negative fibrocytes in the spiral limbus.     

Evolutionary trends of the hairy-faceSaguinus in terms of the dental and cranial morphology

Shape variations in the dentition and the cranium were analyzed for sevenSaguinus forms of the hairy-face tamarin by applying the factor analysis method. The results obtained for the dental and cranial measurements were almost consistent with each other. The magnitude of the difference in shape factors between theS. nigricollis group and theS. midas group is appreciably larger than that between the former group and theS. mystax group. If the ancestral geographic centre of origin is postulated as being within the region which is inhabited by the livingS. nigricollis group, the morphological distances between any pairs of groups correlate well with the geographic distances between them. Concerning the dental and cranial morphologies, the physical changes in the three species group probably took place in two directions; that is, from theS. nigricollis group to theS. mystax group, and from theS. nigricollis group to theS. midas group. The forms belonging to each species group are more closely related to each other, with the exception ofS. imperator in theS. mystax group. The uniqueness ofS. imperator was clearly demonstrated by factor analysis and distance analysis. In theS. mystax group, although still hypothetical,S. imperator may have been related only through the basic ancestral stock toS. labiatus andS. mystax.     

Cytosolic adenylate kinase catalyzes the synthesis of thiamin triphosphate from thiamin diphosphate

An attempt was made to purify a porcine skeletal muscle enzyme catalyzing the formation of thiamin triphosphate (TTP) from thiamin diphosphate (TDP), requiring ATP, Mg2+ and a cofactor (creatine). As the purification proceeded, the reaction requirements for ATP and creatine were lost and then a requirement for ADP was manifested. The activity responsible for TTP synthesis from TDP, ADP, and Mg2+ was found to be copurified with adenylate kinase [EC 2.7.4.3] activity, and was finally purified to a single band on SDS-PAGE. Antiserum obtained against the purified enzyme preparation inhibited both adenylate kinase activity and the TTP-synthesizing activity to exactly the same extent. These results indicate that adenylate kinase catalyzes TTP formation from TDP in vitro.     

Comparison of growth properties of carrot hairy root in various bioreactors

Summary Growth properties of carrot hairy root cells in various bioreactors were investigated. A turbine-blade reactor and an immobilized rotating drum reactor were found to be advantageous for the hairy root culture because of a high oxygen transfer coefficient (k in L a). After 30 days of culture, 10 g/l of dry hairy root cells were obtained in both bioreactors and maximum growth rates (V _m ) were found to be 0.63 and 0.61 g/l per day for the turbine-blade reactor and immobilized rotating drum reactor, respectively. Specific growth rates () at various cultivation times were observed to be linearly proportional to X/k _l a for both bioreactor configurations where X is the cell concentration. The estimated specific oxygen uptake rate of 0.34 mmol O₂/g dry cells per hour compares fairly well with an experimental value of 0.3.     

A cladistic analysis of interspecific relationships ofSaguinus

The dental and cranial morphologies of all species ofSaguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess the interspecific relationships ofSaguinus.Saguinus are divided into two main groups; one consists ofS. oedipus, S. geoffroyi, andS. leucopus, and the other includesS. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas. In the former group,S. oedipus is more closely related toS. geoffroyi than either is toS. leucopus. In the latter group,S. labiatus, S. mystax, andS. imperator are classified into one group, andS. bicolor andS. midas form one monophyletic group.     

Cloning and expression of cDNAs from enterically-transmitted non-A, non-B hepatitis virus.

The fragment gene of enterically-transmitted non-A, non-B hepatitis virus (ET-NANBHV) was cloned as a cDNA and inserted into an expression vector pUEX2. The recombinant protein was expressed in Escherichia coli HB101 as a fusion protein with beta-galactosidase (beta-Gal). The fusion protein reacted with the sera of infected cynomolgus monkeys and of patients from Myanmar. This reaction was highly related with ET-NANBHV infection, and obviously demonstrates in that the recombinant protein can be used for the detection of ET-NANBHV infection.     

Food preferences and nematode parasitism in mycophagousDrosophila

Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom onPleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of thequinaria species-group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, onlyD. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagousDrosophila. D. pirka, D. trivittata andD. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo. Bionomics of Drosophilidae (Diptera) in Hokkaido, IX.     

Molecular cloning and nucleotide sequence of a gene for alkaline cellulase from Bacillus sp. KSM-635

A gene for alkaline cellulase from the alkalophilic Bacillus sp. KSM-635 was cloned into the HindIII site of pBR322 and expressed in Escherichia coli HB101. Although the recombinant plasmid contained two HindIII inserts of 2.6 kb and 4.0 kb, the inserts were found to be contiguous in the Bacillus genome by hybridization analysis. Nucleotide sequences of a 2.4 kb region which was indispensable for the production of cellulase, and the flanking, 1.1 kb region, were determined. There was an open reading frame (ORF) of 2823 bp in the 3498 bp sequence determined, which encoded 941 amino acid residues. Two putative ribosome-binding sites and a sigma 43-type, promoter-like sequence were found upstream from an initiation codon in the ORF. The deduced amino-terminal sequence resembles the signal peptide of extracellular proteins. A region of amino acids, 249 to 568, of the deduced amino acid sequence of the cellulase from this organism is homologous with those of alkaline and neutral enzymes of other micro-organisms, but nine amino acid residues were found to be conserved only in the alkaline enzymes.