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.     

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.     

Purification and characterization of diabetes-inducible cytochrome P-450

A diabetes-inducible form of cytochrome P-450, termed P-450DM, was purified to electrophoretical homogeneity (MW 51,000) by high-performance liquid chromatography from liver microsomes of diabetic rats induced with streptozotocin. The CO-reduced absorption maximum of P-450DM was at 452 nm and the oxidized heme iron appeared to be predominately in the high-spin state as deduced from the Soret maximum at 395 nm. P-450DM was active in aniline hydroxylation and N-nitrosodimethylamine demethylation. The dealkylation activity toward 7-ethoxycoumarin by P-450DM was much enhanced by the addition of cytochrome b5.     

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.     

Expression of adenovirus type 12 early region 1 in KB cells transformed by recombinants containing the gene.

The adenovirus type 12 (Ad12) early region 1 (E1) gene was introduced into KB cells by using a dominant selection vector, pSV2-gpt, and over 80 Gpt+ KB cell clones were established. Three types of recombinant DNAs (gAE1A, gARC, and gABA) were constructed. They contained the AccI-H, EcoRI-C, and BamHI-A fragments, respectively, of Ad12 DNA in pSV2-gpt. Five of 50 (10%) gABA-transformed cell clones, 12 of 18 (67%) gAE1A-transformed cell clones, and 10 of 18 (56%) gARC-transformed cell clones complemented the growth of Ad5 dl312 (deletion in E1A) and were designated as Gpt+ Ad+ cell clones. In these cell clones at their early passages, recombinant genome sequences were detected in cellular DNA and were expressed. T antigen g (the E1A gene product) was detected by immunofluorescence. The Gpt+ Ad+ cell clones supported the growth of Ad5 deletion mutants in parallel with the expression of Ad12 E1A or E1A plus E1B genes. After infection of Gpt+ Ad+ cell clones with Ad5 dl312, the early genes of dl312 were efficiently transcribed, indicating the expression of the pre-early function of the Ad12 E1A gene. Two clones each from gAE1A-,gARC-, and gABA-transformed cells were subcultured for a long period to determine the stability of the transfecting DNAs. Subculture in a nonselective medium resulted in cells which lost the transfecting DNAs. Subculture in a selective medium resulted in the selection of cells which maintained the gpt gene expression but lost the Ad12 gene expression. These results indicate that the transfecting DNA is present in an unstable state in KB cells.     

Inactivation of T Antigen-Forming Capacities of Simian Virus 40 and Adenovirus 12 by Ultraviolet Irradiation

Methods to measure T antigen-forming capacities of simian virus 40 (SV40) and adenovirus 12 (Ad12) were investigated, and a method to measure the capacity in terms of T antigen-forming units was employed by the use of cytosine arabinoside. Plaque-forming units and T antigen-forming units of SV40, SV40 deoxyribonucleic acid, or Ad12 were inactivated by ultraviolet (UV) irradiation at the same rate, roughly following a single-hit curve. T-antigen formation by UV-irradiated SV40 and Ad12 was enhanced in cells multiply infected and in cells in a growing state. These observations showed that it was difficult or impossible to estimate the size of the gene for T antigen by UV inactivation.