巻号一覧
28 巻, 1 号
February
選択された号の論文の8件中1～8を表示しています
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Full Papers
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Keisuke TSUTSUI, Masato KAKU, Masahide MOTOKAWA, Yuiko TOHMA, Toshitsu ...2007 年 28 巻 1 号 p. 1-7
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーIt has been reported that reduction of masticatory afferent stimulation might influence learning and memory function. In order to clarify the influences of reduced masticatory sensory input on spatial memory/learning ability and neuropathological changes, we conducted the Morris water maze experiment and investigated the number of hippocampal neurons in association with the differences in masticatory afferent stimuli from hard- and soft-diet feeding in mice. The water maze experiment showed no significant difference in learning ability between 180-day-old solid- and powderdiet groups. Meanwhile, the ability was significantly reduced in the 360-day-old powder-diet group as compared with the age-matched solid-diet group. The total number of pyramidal cells in the hippocampal CA1 and CA3 regions was significantly smaller in 360-day-old powder-diet group than in the remaining groups. These results demonstrate that reduction of masticatory afferent stimuli due to long-term soft-diet feeding may induce neuron loss in the hippocampus and reduced memory/learning ability.抄録全体を表示PDF形式でダウンロード (968K) -
Annie JOUBERT, Sumari MARAIS2007 年 28 巻 1 号 p. 9-16
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーThe influence of 1 × 10-6 M exogenous 2-methoxyestradiol (2ME) was investigated on nuclear and cytoplasmic morphology, as well as Cdc (cell division cycle) 2 kinase activity in WHCO3 esophageal carcinoma cells. Mitotic indices after 18 h of 2ME exposure revealed an increase in metaphase cells (9.0%) when compared to the vehicle-treated cells (0.9%). 2ME-treated cells showed apoptotic cells at 5.6% after 18 h of exposure to dimethyl sulphoxide, compared to 0.9% in vehicle-treated cells. Increased morphological characteristics of apoptosis were observed in 2ME-treated cells after 21.5 h of exposure. Twelve percent of cells were in apoptosis when compared to the 1.6% of vehicle-treated cells. Furthermore, 42.4% of cells were arrested in metaphase after 21.5 h of 2ME exposure compared to 2.9% of vehicle-control cells present in metaphase. Cdc2 kinase activity was statistically significantly increased (1.7-fold) (P ‹ 0.005) after 18 h of 2ME exposure when compared to vehicle-treated controls. Although the mechanism of 2ME's action on esophageal carcinoma cells is not yet elucidated, the present study revealed that 2ME caused metaphase arrest, as well as an increase in Cdc2 kinase activity that culminated in the induction of apoptosis in these cells.抄録全体を表示PDF形式でダウンロード (1293K) -
Yasuo OHTANI, Mineyoshi HIYOSHI, Tomoichi OHKUBO, Kimiyoshi TSUJI, Mas ...2007 年 28 巻 1 号 p. 17-23
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーWe found a substance in culture medium of neonatal pig liver fragments, which suppresses an immune response monitored by 3H-thymidine incorporation using phytohemagglutinin (PHA)-stimulated lymphocytes. We named it as an immunosuppressive factor (ISF). To purify ISF, ammonium sulfate fractionation, DE52, SP-Sephadex, hydroxyapatite, blue Sepharose, heparin Sepharose and Superdex gel filtration columns were used. Using these purification procedures, ISF was purified 1,254-fold, with 9.2% recovery, from the culture medium of neonatal pig liver fragments, and was identified as arginase by its biochemical characteristics including molecular size, amino acid sequences of digested peptides and expression of arginase activity. The addition of ISF caused to decrease in arginine concentration in culture medium and at the same time DNA synthesis was suppressed dose-dependently, both of which were recovered by the addition of NOHA (NG-hydroxy-L-arginine), an arginase inhibitor. In addition, the depletion of arginine in culture medium also led to the inhibition of DNA synthesis. These results led us to the conclusion that immunosuppressive effect of ISF was due to arginase activity that decreased arginine concentration in culture medium, not to another function of ISF.抄録全体を表示PDF形式でダウンロード (820K) -
Katsuhide KUROKAWA, Shinichi ABE, Koji SAKIYAMA, Tomotaka TAKEDA, Yosh ...2007 年 28 巻 1 号 p. 25-31
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーIn vivo studies have shown that changes in the characteristics of skeletal muscle fiber are determined by type of exercise or training. These earlier studies on mechanical stimulation, however, have all employed stimulation applied at a constant intensity, and no studies appear to have investigated change with variation of intensity of stimulation. In this study, we investigated the characteristics and differentiation of myoblasts stretched at different rates. Myoblasts were stimulated at 3 different rates, and the numbers of cells and nuclei on days 1, 3, and 5 were compared. The myosin heavy chain (MyHC) mRNA expression level was also compared. We investigated expression of MyHC-perinatal to determine speed of differentiation of myoblasts, and expression of MyHC-2b, 2d, and 2a to ascertain muscle cell characteristics. Counting cells and nuclei of myoblasts revealed clear promotion of differentiation with stretching. With rapid stretching, expression of MyHC-perinatal was high at first, but then showed a decrease. In terms of effect on muscle fiber characteristics, MyHC-2b, MyHC-2d, and MyHC-2a were high with rapid, medium, and slow stretching, respectively. This indicated that myoblast differentiation was promoted regardless of difference in stretching speed, with the myoblasts acquiring the muscle-fiber characteristics appropriate to each rate of stretching.抄録全体を表示PDF形式でダウンロード (4445K) -
Kazumasa OHTA, Rintarou OKOSHI, Maiko WAKABAYASHI, Ayako ISHIKAWA, Yut ...2007 年 28 巻 1 号 p. 33-42
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーGeldanamycin, a heat-shock protein 90 (Hsp90)-binding agent, modulates various cellular activities. The present study found that, although geldanamycin by itself had no effect on thymocyte viability, it induced apoptosis in thymocytes with a reduction of the mitochondrial transmembrane potential (ΔΨm) in the presence of 12-O-tetradecanoylphorbol 13-acetate (TPA), an activator of protein kinase C (PKC). This apoptosis depended on transcription and translation, and on activation of caspase-8 and -3. Geldanamycin treatment in the presence of TPA also enhanced destabilization of Lck. This destabilization was independent of transcription and translation. It was inhibited, however, by conventional PKC inhibitors, preventing apoptosis. Proteasome inhibitor affected neither the degradation of Lck nor DNA fragmentation, although they inhibited reduction of ΔΨm. These results suggest that the ubiquitin-proteasome system is not involved in Lck destabilization, and that ΔΨm reduction is not directly related to the progression of apoptosis. Furthermore, inhibition of Lck in the presence of TPA induced apoptosis in thymocytes. Our findings suggest that Hsp90 modulates thymocyte apoptosis in concert with PKC through the destabilization of Lck and in a caspase-8- and -3-dependent manner.抄録全体を表示PDF形式でダウンロード (924K) -
Kouichi ABE, Takuji SUZUKI, Mitsuhiro IJIRI, Yu KOYAMA, Mamoru ISEMURA ...2007 年 28 巻 1 号 p. 43-48
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーPreviously, we reported that the oral administration of green tea rich in catechins restored levels of several biomarkers increasing in galactosamine-treated rats to nearly control values. These biomarkers included serum transaminase activities, serum concentrations of tumor necrosis factor-α and interleukin 1-β, and the hepatic mRNA expression of these inflammatory cytokines. In the present study, we examined possible anti-fibrotic effects of green tea in galactosamine-induced hepatitis. The results of the reverse transcription and polymerase chain reaction indicated that the increase in gene expression of the α1 chain of collagen type 1 and transforming growth factor β-1 in the injured liver 24 h post-injection of galactosamine was suppressed by the administration of green tea. Masson's trichrome staining demonstrated that the extent of fibrogenesis after 14 days was greater in the galactosamine-injured livers not treated with green tea than the treated ones. These results suggest that the drinking of green tea with a high catechin content may help to prevent and/or attenuate the development of fibrosis in hepatitis.抄録全体を表示PDF形式でダウンロード (3549K) -
Shigenobu MATSUMURA, Takafumi MIZUSHIGE, Takeshi YONEDA, Toshihiko IWA ...2007 年 28 巻 1 号 p. 49-55
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーWe investigated the expression of G protein-coupled receptor GPR40 and GPR120 in the rat tongue. Using reverse transcription polymerase chain reaction, we detected a significant expression of GPR120 mRNA in the epithelium of the circumvallate papillae but not in the nonsensory epithelium, while the expression of GPR40 mRNA was undetectable in the sensory papillae. Western blotting analysis of colon and circumvallate papillae for GPR120 showed a protein band with a molecular weight that corresponds to that of GPR120, indicating that this antibody could recognize a native form of GPR120. Immunohistochemistry using anti-GPR120 antibody revealed GPR120 immunoreactivity in the enteroendocrine cells of the colon. Furthermore, some cells in each taste bud were stained positively with more intense labeling in the apical part of the cells. These results suggested that GPR120 is expressed in the taste cells of the circumvallate papillae to sense dietary fat, like the receptor expressed in the enteroendocrine cells.抄録全体を表示PDF形式でダウンロード (4500K)
Communication
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Rei DEN, Masahiro TODA, Shingo NAGASAWA, Kazuyuki KITAMURA, Kanehisa M ...2007 年 28 巻 1 号 p. 57-60
発行日: 2007年
公開日: 2007/03/13
ジャーナル フリーWe investigated the circadian rhythm of chromogranin A (CgA) concentrations in saliva and blood samples from 40 male college students collected at 7 : 00, 8 : 00, 10 : 30, 12 : 30, 17 : 30, and 22 : 30. CgA concentrations were determined by ELISA. Salivary CgA levels peaked upon awakening, and then quickly decreased to the nadir after 1 hour and maintained a low level throughout the day. On the other hand, plasma CgA did not show any obvious circadian rhythm. These findings suggest that salivary and plasma CgA has different routes of secretion.抄録全体を表示PDF形式でダウンロード (555K)
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