Respiration of adult female Calanus hyperboreus (Copepoda) during spring in the North Water Polynya

The respiration rate of adult female Calanus hyperboreus was determined in order to assess physiological activity and its relationship to food availability during spring in the North Water Polynya, northern Baffin Bay. The respiration rate increased hyperbolically with increasing ambient chlorophyll α (Chl. α) concentration regardless of the reproductive status. The increase of respiration with Chl. α concentration may be caused by activated feeding behavior. This suggests that all adult females during spring were physiologically active individuals. Possible advantages of the rapid response to food concentration in adult female copepods are discussed

Ab initio study on stability of half-metallic Co-based full-Heusler alloys

科研費報告書収録論文(課題番号:16310081/研究代表者:白井正文/ナノ磁性材料におけるスピン構造とそのダイナミクスに関する理論研究

Half-metallicity at the (110) interface between a full Heusler alloy and GaAs

科研費報告書収録論文(課題番号:16310081/研究代表者:白井正文/ナノ磁性材料におけるスピン構造とそのダイナミクスに関する理論研究

Detection and analyses by gel electrophoresis of cisplatin-mediated DNA damage.

DNA damage induced by cis-diamminedichloroplatinum (II) (cisplatin: cis-DDP), an anticancer drug, was studied in vitro by monitoring the drug-induced conformational change of pUC18 plasmid DNA, the sensitivity to some restriction enzymes of the damaged DNA and the sequence-dependent termination of DNA synthesis caused by cisplatin. Closed circular, superhelical pUC18 DNA was treated at 37 degrees C for 16 h with various concentrations of cisplatin. Cisplatin-dose-dependent conformational change due to unwinding of the treated DNA was detected by agarose gel electrophoresis. To analyze the base-specificity of the cisplatin damage, the measurement for sensitivity of cisplatin-treated DNA to various types of restriction enzyme and sequence gel analysis of the treated DNA were conducted. The results suggested that cisplatin attacked preferentially the sequence of GG &#62; AG &#62; GNG in the order. In the present assay condition, the cisplatin/DNA nucleotide ratios required for the DNA damage detection were roughly 0.025 for the conformational analysis, 0.001 or more for the restriction enzyme analysis, and less than 0.001 for the sequence gel analysis. By using the present method, it was demonstrated that the cisplatin-mediated DNA damage was inhibited by NaCl, KCl, CaCl2 or MgCl2 at their nearly physiological concentrations, and by reducing agents such as thiourea and 2-mercaptoethanol in the reaction mixture.</p

Non-radioactive hybridization probes prepared using M13 phage vector and the universal sequencing primer.

Non-radioactive hybridization probes were prepared using the M13 phage vector and the universal sequencing primer. The probe sequence to be used was first cloned into the M13 vector, and the minus strand of the template DNA was then synthesized with the Klenow fragment of E. coli DNA polymerase I in the presence of the biotinylated nucleotide, biotin-11-dUTP, as a label. Resultant DNA was heavily biotinylated, and made up of the entire minus strand of the template DNA. The long tag sequence derived from the M13 vector may increase the sensitivity of the detection. The biotinylated hybrids were visualized with the streptavidin-alkaline phosphatase conjugate and chromogenic substrates. As shown by Southern hybridization, the probe prepared in this way could be used to detect less than 1 pg of target sequence and a single copy gene sequence in human genomic DNA within several hours of signal development.</p

Studies on Hydrocarbon-utilizing Microorganisms : Part II. Screening of Hydrocarbon-utilizing Bacteria Producing Antibiotic Substances from Kerosene

Forty-four bacterial isolates were subjected to screening test for production of antibiotic substance from kerosene. Twenty-two isolates were found to produce antibiotic substance : 19 isolates against Streptomyces and 3 isolates against bacteria. But no isolates produced any antibiotics against moulds and yeasts

Therapy for CKD-associated muscle dysfunction

Background Chronic kidney disease (CKD) patients experience skeletal muscle wasting and decreased exercise endurance. Our previous study demonstrated that indoxyl sulfate (IS), a uremic toxin, accelerates skeletal muscle atrophy. The purpose of this study was to examine the issue of whether IS causes mitochondria dysfunction and IS-targeted intervention using AST-120, which inhibits IS accumulation, or mitochondria-targeted intervention using L-carnitine or teneligliptin, a dipeptidyl peptidase-4 inhibitor which retains mitochondria function and alleviates skeletal muscle atrophy and muscle endurance in chronic kidney disease mice. Methods The in vitro effect of IS on mitochondrial status was evaluated using mouse myofibroblast cells (C2C12 cell). The mice were divided into sham or 5/6-nephrectomized (CKD) mice group. Chronic kidney disease mice were also randomly assigned to non-treatment group and AST-120, L-carnitine, or teneligliptin treatment groups. Results In C2C12 cells, IS induced mitochondrial dysfunction by decreasing the expression of PGC-1α and inducing autophagy in addition to decreasing mitochondrial membrane potential. Co-incubation with an anti-oxidant, ascorbic acid, L-carnitine, or teneligliptine restored the values to their original state. In CKD mice, the body and skeletal muscle weights were decreased compared with sham mice. Compared with sham mice, the expression of interleukin-6 and atrophy-related factors such as myostatin and atrogin-1 was increased in the skeletal muscle of CKD mice, whereas muscular Akt phosphorylation was decreased. In addition, a reduced exercise capacity was observed for the CKD mice, which was accompanied by a decreased expression of muscular PCG-1α and increased muscular autophagy, as reflected by decreased mitochondria-rich type I fibres. An AST-120 treatment significantly restored these changes including skeletal muscle weight observed in CKD mice to the sham levels accompanied by a reduction in IS levels. An L-carnitine or teneligliptin treatment also restored them to the sham levels without changing IS level. Conclusions Our results indicate that IS induces mitochondrial dysfunction in skeletal muscle cells and provides a potential therapeutic strategy such as IS-targeted and mitochondria-targeted interventions for treating CKD-induced muscle atrophy and decreased exercise endurance