硝子体の構造とその液化との関係

The aim of the study is to clarify the vitreous body structure and liquefaction phenomena. It was found that when melting a frozen rabbit vitreous body, the gel-sol transition phenomenon occurs and the gel structure is broken. This is almost like the liquefaction of the vitreous body in vivo. We try to clarify the liquefaction phenomenon by using this animal model. The native vitreous body has three dimensional meshwork structures. After liquefaction, it is changed into two parts, namely fiber aggregates and soluble amorphous aggregates. The surface of native vitreous body meshwork is mucopolysacharide, but that of fiber aggregates after liquefaction is changed into connective tissue, which means the conformational change of vitreous body in liquefaction. The soluble proteins after liquefaction were analyzed and identified as crystallin family. It is suggested that the liquefaction is induced by detachment of non-collagenous protein beads containing crystallins, resulting in the collapse of the three dimensional structure to release watery liquid trapped within. And the new gel-sol transition model of vitreous bod is proposed.博士（医学）・乙1330号・平成26年3月17

Squalene Quantification Using Octadecylbenzene as the Internal Standard

AbstractSqualene was determined by HPLC using octadecylbenzene (ODB) as an internal standard. Squalene and ODB were monitored at 210nm. The retention times of squalene and ODB were 7.59 and 8.54min, respectively. Squalene was determined from the peak area ratios of squalene/ODB detected at 210nm. After treatment with 0.5M KOH containing ethanol at 90°C for 1h, squalene in the saponified lipid fraction was extracted using n-hexane. No interfering peak was observed. Linearity of this method was observed in the range 80–900 ng. ODB is useful as an internal standard for squalene determinations

Evolutionary conservation and changes in insect TRP channels

<p>Abstract</p> <p>Background</p> <p>TRP (Transient Receptor Potential) channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP channels and the mechanisms of integrating sensory inputs in insects, we have identified and compared TRP channel genes in <it>Drosophila melanogaster, Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis</it>, and <it>Pediculus humanus </it>genomes as part of genome sequencing efforts.</p> <p>Results</p> <p>All the insects examined have 2 TRPV, 1 TRPN, 1 TRPM, 3 TRPC, and 1 TRPML subfamily members, demonstrating that these channels have the ancient origins in insects. The common pattern also suggests that the mechanisms for detecting mechanical and visual stimuli and maintaining lysosomal functions may be evolutionarily well conserved in insects. However, a TRPP channel, the most ancient TRP channel, is missing in <it>B. mori</it>, <it>A. mellifera</it>, and <it>N. vitripennis</it>. Although <it>P. humanus </it>and <it>D. melanogaster </it>contain 4 TRPA subfamily members, the other insects have 5 TRPA subfamily members. <it>T. castaneum</it>, <it>A. mellifera</it>, and <it>N. vitripennis </it>contain TRPA5 channels, which have been specifically retained or gained in Coleoptera and Hymenoptera. Furthermore, TRPA1, which functions for thermotaxis in <it>Drosophila</it>, is missing in <it>A. mellifera </it>and <it>N. vitripennis</it>; however, they have other Hymenoptera-specific TRPA channels (AmHsTRPA and NvHsTRPA). NvHsTRPA expressed in HEK293 cells is activated by temperature increase, demonstrating that HsTRPAs function as novel thermal sensors in Hymenoptera.</p> <p>Conclusion</p> <p>The total number of insect TRP family members is 13-14, approximately half that of mammalian TRP family members. As shown for mammalian TRP channels, this may suggest that single TRP channels are responsible for integrating diverse sensory inputs to maintain the insect sensory systems. The above results demonstrate that there are both evolutionary conservation and changes in insect TRP channels. In particular, the evolutionary processes have been accelerated in the TRPA subfamily, indicating divergence in the mechanisms that insects use to detect environmental temperatures.</p

On the Bio-Rearrangement into Fully Saturated Fatty Acids-Containing Triglyceride in Aurantiochytrium sp

AbstractA strain of Aurantiochytrium sp. was grown in media with various concentrations of glucose to monitor triglyceride production as a potential source of oil for biodiesel. The fatty acid composition of triglyceride in the strain was unique, because the fatty acids consisted of only 6 molecular species, and the major species were myristic, pentadecanoic, palmitic, heptadecanoic, docosapentaenoic, and docosahexaenoic acids. When cells were cultured in glucose-rich (over 9%) medium for 4 days, the triglyceride yields were 0.5-1.0g/L. After culture for 4 days, the fatty acid composition of triglyceride was nearly identical in all cells grown in media containing various concentrations of glucose. However, when cells were grown in medium containing 12% glucose for 12 days, unique triglyceride containing only saturated fatty acids accumulated. This bio-rearrangement into fully-saturated fatty acids-containing triglyceride may be utilized for the preparation of biodiesel oil

Critical Point Mutations for Hepatitis C Virus NS3 Proteinase

AbstractThe hepatitis C virus NS3 proteinase plays an essential role in processing of HCV nonstructural precursor polyprotein. To detect its processing activity, we developed a simpletrans-cleavage assay. Two recombinant plasmids expressing the NS3 proteinase region and a chimeric substrate polyprotein containing the NS5A/5B cleavage site between maltose binding protein and protein A were co-introduced intoEscherichia colicells. The proteinase processed the substrate at the single site during their polyprotein expression. Deletion analysis indicated that the functionally minimal domain of the NS3 proteinase was composed of 146 amino acids, 1059 to 1204. We isolated several cDNA clones encoding the functional domain of the NS3 proteinase from the sera of patients chronically infected with HCV and determined their proteinase activity by thistrans-cleavage assay. Both active and inactive clones existed in the same patients. Comparative sequence analyses of these clones suggested that certain point mutations seemed to be related to the loss of proteolytic activity. This was confirmed by back mutation experiments. Among the critical mutations, Pro-1168 to Thr and Arg-1135 to Gly were intriguing. These amino acids, which are situated near the oxyanion hole, seem to be essential for maintaining the conformation of the active center of the NS3 proteinase

Electrical Resistivity Studies of Hydrogenated Pd-Zr Glasses

The effect of hydrogen absorption on the electrical resistivity is studied for Pd-Zr glasses prepared by melt-quenching using a single roll technique. The temperature coefficients of the electrical resistivity are negative over the temperature range between 4.2 and 300 K for both as-quenched Pd_Zr_ and hydrogenated Pd_Zr_H_ glasses. The results can be interpreted in terms of an acoustical phonon in case of Pd_Zr_ glass, while in Pd_Zr_H_ glass an optical phonon originating from the metal-hydrogen interaction has a significant contribution to the electrical resistivity as well as an acoustic phonons