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61.
During temperature acclimation of Tetrahymena pyriformis, the changes in fluidity and composition of total lipids from three membrane fractions, mitochondria, pellicles and microsomes were studied by a spin-label technique using a stearate probe and thin-layer and gas-liquid chromatography. The increase of fluidity observed in microsomal and pellicular lipids following the temperature shift from 39 to 15 degrees C corresponds with the increase of the ratio of total unsaturated to saturated fatty acid content. However, despite the increase of this ratio, the fluidity of mitochondrial lipids was found to be constant up to 10 h after the temperature shift. The fluidity of total lipids of mitochondria isolated from Tetrahymena cells grown at 39 degrees C was not changed by removal of cardiolipin, whereas cardiolipin-depleted lipids of mitochondria from 15 degrees C-acclimated cells showed a decrease in fluidity. The re-addition of cardiolipin to the mitochondrial lipids depleted of cardiolipin restored the fluidity to the initial level, thereby confirming the rigidifying effect of cardiolipin in cold-acclimated cells. These results suggest that cardiolipin may be implicated in maintaining consistent fluidity of mitochondrial membranes against change in thermal environment. 相似文献
62.
Cartilage-derived factor (CDF) : II. Somatomedin-like action on cultured chondrocytes 总被引:2,自引:0,他引:2
Yukio Kato Yoshio Nomura Mitsuko Tsuji Hiroaki Ohmae Masahiko Kinoshita Shinji Hamamoto Fujio Suzuki 《Experimental cell research》1981,132(2):339-347
Previously, we showed that fetal bovine cartilage contains a polypeptide that stimulates the incorporation of [35S]sulfate into proteoglycans synthesized by rat and rabbit costal chondrocytes in culture. In this paper, we report that the cartilage-derived factor (CDF) increases not only [35S]sulfate incorporation but also [3H]thymidine incorporation into rabbit chondrocytes in monolayer culture. The dose-response curve of CDF stimulation of DNA synthesis was similar in profile to that of CDF stimulation of proteoglycan synthesis. In addition, CDF markedly enhanced [3H]uridine incorporation into rabbit chondrocytes and significantly enhanced [3H]serine incorporation into total protein. These findings indicate that fetal bovine cartilage contains a factor that shows somatomedin-like activity in monolayer cultures of rabbit chondrocytes. 相似文献
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65.
A 13C-nmr study of the salt-induced helix–coil transition of the basic polypeptides poly(L -lysine) [(Lys)n], poly(L -arginine) [(Arg)n], and poly (L -ornithine) [(Orn)n] was performed to serve as a reference of the helical portion of histones and other proteins. As is the case with pH-induced helix–coil transition, the downfield displacement of the Cα and carbonyl carbon signals are observed in the helical state. The upfield shift of the Cβ signals, on the other hand, is noted in the salt-induced transition. Regardless of the differences in the side chains and also the salts used, very similar helix-induced chemical shifts are obtained for (Lys)n and (Arg)n. However, the displacement of the Cα, Cβ, and carbonyl carbons of (Orn)n in the presence of 4M NaClO4 is found to be almost 50% of that of (Lys)n and (Arg)n. This is explained by the fact that the maximum helical content is about 50%, consistent with the ORD result. Further, the motion of the backbone and side chains of the helical from was estimated by measuring the spin-lattice relaxation time (T1), nuclear Overhauser enhancement (NOE), and line width. In the case of (Lys)n, the motion of the side chains is charged very little in comparison with that of the random coil. Indicating that the aggregation of the salt-induced helix is small in contrast to that of the pH-induced helix. For (Arg)n, however, the precipitate of the helical polymers is mainly due to aggregation. 相似文献
66.
Saito Masahiko; Kondo Noriaki; Yamaguchi Hisao; Hashimoto Tohru 《Plant & cell physiology》1976,17(3):411-416
Nine bibenzyls and 10 stilbenes were synthesized as analoguesof batatasin III, a growth inhibitor isolated from dormant yambulbils, and examined for their plant growth-regulating activities.The bioassays used were the elongation of dark-grown intactrice coleoptiles, auxin-induced elongation of excised oat coleoptiles,and germination of rape and barnyard grass seeds. In the elongationof intact rice coleoptiles, 3,3'-dihydroxy-5-methoxy- (batatasinIII), 3,5-dimethoxy-3'-nitro-, 4'-bromo-3-nitro-, 3-amino-3'-chloro-,3-amino-4'-chloro-bibenzyls and 3-benzyloxy-4'-bromo-5-methoxy-,3-benzyloxy-3',4'-dichloro-5-methoxy-stilbenes were inhibitory,and 4'-bromo-3-nitrostilbene was promotive at a concentrationof 100 mg/liter. The results obtained by the other bioassayswere qualitatively consistent with these findings, although3-amino-4'- chlorobibenzyl and 4'-bromo-3-nitrostilbene werenot tested in all the bioassays. In the seed germination, which was rather tolerant to the testanalogues, batatasin III was inactive but 3-benzyloxy-4'-bromo-5-methoxy-and 3-benzyloxy-3',4'-dichloro- 5-methoxystilbenes were veryactive. Thus, if substituted properly, bibenzyls and stilbenes are activewithout hydroxyl and methoxyl group(s) as the functional group.
3 Present address: The National Institute for EnvironmentalStudies, Yatabc, Ibaraki 300-21, Japan. (Received November 19, 1975; ) 相似文献
67.
Shiro Ohki Yoshimasa Nishigaki Katsuhiro Imaki Masayasu Kurono Fumio Hirata Toshio Hanyu Nobuhiko Nakazawa 《Prostaglandins & other lipid mediators》1976,12(2):181-186
Radioimmunoassay technique for measuring 5α,7α-dihydroxy-11-keto-tetranorprosta-1,16-dioic acid, the main urinary metabolite of PGF1α and PGF2α (PGF2α-MUM), was further improved.It was postulated based on some experimental data that the PGF2α-MUM exists in the urine mostly as dioic acid form, not as δ-lactone formThe daily excretion of PGF2α-MUM in men ranged from 14.43 μg to 36.14 μg and in women from 5.21 μg to 14.25 μg. 相似文献
68.
Keishi Abe Yoichi Otsuka Minoru Yasujima Satoru Ciba Masahide Seino Nobuo Irokawa Kaoru Yoshinaga Fumio Hirata Shiro Ohki Nobuhiko Nakazawa Toshio Hanyu 《Prostaglandins & other lipid mediators》1976,12(5):843-848
The excretion rates of main urinary metabolite of PG F2α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F2α. 相似文献
69.
Lactobacillus casei YIT 9018 (LC 9018) augmented the natural killer (NK) cell activity of spleen cells from inbred BALB/c mice injected intravenously with LC 9018 or intraperitoneally with polyinosinate-polycytidylate. Augmentation of this activity by LC 9018 was also observed in male C3H/He, CBA/N, and C57BL/6 mice. The spleen cells exhibited no cytolytic activity against P815, a cell line insensitive to NK cells. The cytolytic activity of the spleen cells increased 2 days after the injection of 250 μg of LC 9018/mouse, peaked on day 3, and gradually declined thereafter. The increase caused by LC 9018 was also observed in normal and Meth A-bearing mice. In vitro treatment with anti-asialo GM1 antibody plus complement completely-abrogated the LC 9018-augmented murine NK cell activity. The NK activity on the 3rd day after LC 9018 injection was reduced by in vitro treatment with anti-Thy 1.2 monoclonal antibody plus complement to half of that observed when treatment was with complement alone. This suggests that there were two populations of NK cells in the spleen cell suspension derived from LC 9018-treated mice. One population was asialo GM1-positive and Thy 1-negative, the other was asialo GM1-positive and Thy 1-positive. 相似文献
70.
Masahiko Saito Tomohiro Fukuhara Satoshi Kamimura Hiroyuki Ichikawa Hiroyuki Yoshida Tomoyuki Koganezawa Yutaka Ie Yasunari Tamai Hyung Do Kim Hideo Ohkita Itaru Osaka 《Liver Transplantation》2020,10(7)
Controlling the energetics and backbone order of semiconducting polymers is essential for the performance improvement of polymer‐based solar cells. The use of fluorine as the substituent for the backbone is known to effectively deepen the molecular orbital energy levels and coplanarize the backbone by noncovalent interactions with sulfur of the thiophene ring. In this work, novel semiconducting polymers are designed and synthesized based on difluoronaphthobisthiadiazole (FNTz) as a new family of naphthobisthiadiazole (NTz)–quaterthiophene copolymer systems, which are one of the highest performing polymers in solar cells. The effect of the fluorination position on the energetics and backbone order is systematically studied. It is found that the dependence of the solar cell fill factor on the active layer thickness is very sensitive to the fluorination position. It is thus further investigated and discussed how the structural features of the polymers influence the photovoltaic parameters as well as the diode characteristics and bimolecular recombination. Further, the polymer with fluorine on both the naphthobisthiadiazole and quaterthiophene moieties exhibits a quite high power conversion efficiency of 10.8% in solar cells in combination with a fullerene. It is believed that the results would offer new insights into the development of semiconducting polymers. 相似文献