Biomedical Research
Online ISSN : 1880-313X
Print ISSN : 0388-6107
ISSN-L : 0388-6107
32 巻 , 2 号
April
選択された号の論文の13件中1~13を表示しています
Full Papers
  • Yoshiyuki Moriguchi, Kenji Yogo, Ken Aizawa, Ken-ichi Serizawa, Yoshih ...
    2011 年 32 巻 2 号 p. 83-90
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    The pathological influences of inflammation on left ventricular hypertrophy (LVH) were studied in subtotal nephrectomized (SNx) rats after 0.3% NaCl loading for 5 weeks. We found that mild hypertension, increased plasma levels of creatinine, inorganic phosphate, asymmetric dimethylarginine (ADMA), and parathyroid hormone (PTH) were observed in the present SNx rats without LVH. In the present study, the NaCl-loaded SNx (SNx + NaCl) rats were characterized by significant LVH and hypertension with aggravated values of all the parameters. We further confirmed that glomerular sclerosis, tubulointerstitial fibrosis, and inflammatory cell infiltration into the tubulointerstitial area, observed in the SNx rats, were more severely caused in the SNx + NaCl rats. In addition, plasma interleukin-6 (IL-6) levels in the SNx + NaCl rats were significantly increased compared to those in the SNx rats. These findings indicated that NaCl-loaded SNx rats developed LVH and hypertension, which were accompanied with increased plasma levels of PTH, creatinine, inorganic phosphorus, ADMA, and IL-6. Thus, these results suggest that inflammation as well as endothelial dysfunction would be correlated with LVH as non-traditional risk factors at the early stage in the present renal failure model.
  • Chihiro Kamagata, Yosiaki Tsuboko, Tadashi Okabe, Chiyo Sato, Atsuhiro ...
    2011 年 32 巻 2 号 p. 91-102
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Some reports have shown that electroconvulsive shock therapy is effective for treating refractory neuropathic pain. However, its mechanism of action remains unknown. This study analyzes changes in protein expression in the brainstems of neuropathic pain model rats with or without electroconvulsive stimulation (ECS). A neuropathic pain model rat is produced by chronic constrictive injury (CCI) of the sciatic nerve. An ECS was administered to rodents once daily for 6 days after the CCI operation. After ECS, the latency to withdrawal from thermal stimulation was significantly increased. The expression of several proteins was changed after CCI. Ten proteins that increased after CCI then had decreased expression levels (close to control) after ECS, and 8 proteins that decreased after CCI then had increased expression levels (close to control) after ECS. In conclusion, ECS improved thermal hypersensitivity in a rat CCI model. Proteomic analysis showed that altered expression levels of proteins in the brainstem of CCI model rats returned to close to control levels after ECS, including many proteins associated with pain. This trend suggests an association of ECS with improved hypersensitivity, and these results may help elucidate the mechanism of this effect.
  • Tomoko Mashidori, Hiromichi Shirataki, Takao Kamai, Fumihiko Nakamura, ...
    2011 年 32 巻 2 号 p. 103-110
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Intracellular vesicle trafficking is the principal transportation system in eukaryotic cells, and is considered to be involved in a variety of processes related to cell proliferation. A protein named alpha-taxilin has been identified as a binding partner of the syntaxin family, which coordinates intracellular vesicle trafficking. To clarify the role of alpha-taxilin in renal cell carcinoma (RCC), we investigated alpha-taxilin protein expression in clear cell RCC tissues. We analyzed alphataxilin protein in matched sets of tumor and non-tumor tissues from the surgical specimens of 52 Japanese RCC patients by Western blotting. We also studied the relation between alpha-taxilin protein expression in tumor tissues and various clinicopathological features. The alpha-taxilin protein level was higher in tumor tissues than in non-tumor tissues (P < 0.05). Increased expression of alpha-taxilin protein in primary tumors was related to local invasion (P < 0.001), pathological vessel invasion (P < 0.001), and metastasis (P < 0.0001). Kaplan-Meier plots of survival for patients with low versus high alpha-taxilin expression revealed that high expression in tumor tissues was associated with shorter overall survival in all patients (P < 0.05) and with shorter disease-free survival in patients without metastasis (P < 0.01). These findings suggest that alpha-taxilin influences the metastatic and invasive potential of RCC.
  • Makihiko Kuhara, Jingshu Wang, Maria Jolina Flores, Zhiwei Qiao, Yukio ...
    2011 年 32 巻 2 号 p. 111-117
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    We examined age-related changes in the protein expression of carbonic anhydrase III (CAIII) in livers of Long-Evans with a cinnamon-like color (LEC) rats using an agouti color (LEA) rats as controls. The levels of the protein of CAIII in the liver of LEC male rats increased before 20 weeks of age, at the stage of acute hepatitis, and were decreased at 54 weeks of age, while those of CAIII in the liver of LEA male rats were highly expressed at all ages. In the normal LEA rats, CAIII showed sexual dimorphism. The level of CAIII in LEA male rat liver relative to female was four times higher. On the other hand, young LEC rat (at 4-12 weeks) showed a higher protein level of CAIII than LEA rats, and then decreased during development of hepatitis. CAIII mRNA also decreased in the LEC rat liver during hepatocarcinogenesis. The level of CAIII in the tumor region was lower than that in the tumor-free region. Immunohistochemical analysis showed that glutathione S-transferase P (GST-P) was positive and CAIII was negative in the precancerous region. The expression of CAIII was suppressed in cancerous lesions in hepatoma-bearing LEC rat liver compared to uninvolved surrounding tissues. These results indicated that suppression of CAIII accompanied hepatocarcinogenesis and it is a secondary consequence of the high copper levels in the liver.
  • Kensuke Yasui, Noriyuki Miyoshi, Hiroki Tanabe, Yoko Ishigami, Ryuuta ...
    2011 年 32 巻 2 号 p. 119-125
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Many biological activities of green tea have been attributed to a major constituent, (-)-epigallocatechin gallate (EGCG). We previously reported that EGCG and a catechin-rich green tea beverage modulated the gene expression of gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), in the mouse liver. However, it remains to be examined whether or not a constituent other than EGCG contributes to the change in gene expression of these enzymes. In this study, we separated the hot water infusion of green tea leaves (GT) into an ethanol-soluble fraction (GT-E) and an EGCG-free water-soluble fraction (GT-W), and examined their effects using rat hepatoma H4IIE cells. The inclusion of GT, GT-E, and GT-W in the culture medium reduced the gene expression of G6Pase and PEPCK. GT-W caused a decrease in expression of the transcription factor HNF4α. Reduced levels of PEPCK and HNF4α proteins were demonstrated in the cells treated with GT-W. GT-W showed an activity similar to insulin, but different from EGCG. Administration of GT-W to mice for 4 weeks reduced the hepatic expression of G6Pase, PEPCK, and HNF4α. These results suggest that green tea contains some component(s) with insulin-like activity distinguishable from EGCG and that drinking green tea may help to prevent diabetes.
  • Yasuyuki Kudo, Satoko Morohashi, Kaori Takasugi, Shinji Tsutsumi, Hiro ...
    2011 年 32 巻 2 号 p. 127-134
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Recent advances in endoscopic submucosal dissection (ESD) techniques contribute to endoscopic treatment of early gastric cancer (EGC). Recognition of chronic atrophic gastritis as the background is important for high-quality detection and diagnosis of EGC. But, relationships between EGC and atrophy of the background gastric mucosa caused by Helicobacter pylori are not well understood. The present study demonstrated histopathological phenotypes of EGC, as well as chronic atrophic gastritis as background mucosa of EGC. We evaluated mucosal heights, number of glands, and degree of intestinal metaplasia (IM) of the background gastric mucosa, using 81 cases of EGC resected by ESD. Gastric phenotype cancer cases showed IM of the background gastric mucosa less frequently, compared with intestinal phenotype cancer cases (score of IM, 1.15 vs. 1.65, P = 0.012). The average mucosal heights around EGC were lower in moderately to poorly differentiated adenocarcinoma cases than well differentiated adenocarcinoma cases (442.6 μm vs. 500.2 μm, P = 0.011). The mucosal atrophy indicated by average heights of background mucosa was low in the gastric phenotype cancer cases, compared with the intestinal phenotype cancercases (452.8 μm vs. 505.6 μm, P = 0.018). In the fundic gland area, the mucosal heights were low in the gastric phenotype cancer cases, compared with the intestinal phenotype cancer cases (413.2 μm vs. 495.5 μm, P = 0.015). Our results using EGC specimens indicated that gastric phenotype cancer and moderately to poorly differentiated adenocarcinoma had atrophic background mucosa with lower mucosal heights and less IM. The atrophic gastric mucosa with less IM is thought to play an important role in gastric carcinogenesis, especially tumoriogenesis of gastricphenotype cancer.
  • Huachun Weng, Chunshen Shen, Gou Hirokawa, Xu Ji, Rie Takahashi, Kana ...
    2011 年 32 巻 2 号 p. 135-141
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    MicroRNAs (miRNAs) are endogenous small RNAs that play an important role in various physiological processes by downregulating target genes. Recently, plasma miRNAs have been investigated as biomarkers for various diseases. In this study, miRNA array analysis in various tissues showed that miR-124 is almost exclusively expressed in the central nervous system and neuronal cells, suggesting that it might be useful as a potential biomarker for neurological diseases. We examined whether plasma concentrations of brain-specific miRNA can serve as a biomarker for cerebral infarction, where the cerebral infarction was modeled by middle cerebral artery occlusion (MCAO) in the rat. Plasma concentrations of miR-124 were significantly elevated at 6 h, and remained elevated at 48 h after MCAO introduction. Thus, plasma concentration of miR-124 provides a promising candidate biomarker for early detection of cerebral infarction.
  • Keisuke Hikosaka, Hidenao Noritake, Wataru Kimura, Nishat Sultana, Moh ...
    2011 年 32 巻 2 号 p. 143-150
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    No suitable mouse model is available for studying chronic liver disease caused by hepatitis C virus (HCV). CD81, claudin-1, scavenger receptor class B type I, and occludin were recently reported to be the important factors in HCV entry into hepatocytes. We made transgenic mice (Alb-CCSO) expressing the four human proteins and examined whether HCV from a patient serum or HCV pseudoparticles (HCVpp) were capable of infecting them. HCV was not detected in the mouse serum after injecting the mice with HCV from a patient serum. We also found no indications of HCVpp entry into primary hepatocytes from Alb-CCSO mice. In addition, HCV-infectible Hep3B cells were fused with HCV-resistant primary mouse hepatocytes and the fused cells showed 35-fold lower infectivity compared to wild-type Hep3B cells, indicating that primary mouse hepatocytes have the inhibitory factor(s) in HCVpp entry. Our results suggest that the expression of the human factors does not confer susceptibility to HCV entry into the liver.
  • Eri Matsubara, Mio Fukagawa, Tsuyoshi Okamoto, Koichiro Ohnuki, Kuniyo ...
    2011 年 32 巻 2 号 p. 151-157
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    (-)-Bornyl acetate is the main volatile constituent in numerous conifer oils and has a camphoraceous, pine-needle-like odor. It is frequently used as the conifer needle composition in soap, bath products, room sprays, and pharmaceutical products. However, the psychophysiological effects of (-)-bornyl acetate remained unclear. We investigated the effects of breathing air mixed with (-)-bornyl acetate at different doses (low-dose and high-dose conditions) on the individuals during and after VDT (visual display terminal) work using a visual discrimination task. The amounts of (-)-bornyl acetate through our odorant delivery system for 40 min were 279.4 μg in the low-dose and 716.3 μg in the high-dose (-)-bornyl acetate condition. (-)-Bornyl acetate induced changes of autonomic nervous system for relaxation and reduced arousal level after VDT work without any influences of task performance in low-dose condition, but not in high-dose condition.
  • Yohko Nakagawa, Eiji Watari, Masumi Shimizu, Hidemi Takahashi
    2011 年 32 巻 2 号 p. 159-166
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Assays for cytotoxicity of CTLs in vivo using a fluorescent-based dye, 5- (and 6-) carboxyfluorescein diacetate succinimydyl ester (CFSE), have been established and widely used. On the basis of this experience, we applied it to in vitro assay system and established a simpe, highly sensitive flow cytometric assay for CTL activity. In our assay, specific activities of CTLs could be detected by a reduction in sensitive target cell numbers on single-color histogram plot analysis. By using this assay, we could determine the changes in cytotoxic activity by single amino acid substitution within an epitope peptide. Adherent cells were also used as target cells in this assay by treatment with excess EDTA and trypsin reagents after incubation with effector CTLs. Furthermore, when fluorescent calibration beads were used as a control, we could determine the cytotoxicity of CTLs against tumor cells. The results obtained from our assay were almost consistent with those from the conventional 51Cr-release assay.Because our assay uses only a stable non-radioactive reagent, CFSE, this assay is safe, inexpensive and extremely easy. These results indicated that this new assay (FACS-CTL assay) would be sufficiently acceptable alternative to classical 51Cr-release assay.
  • Korefumi Nakamura, Kohtaro Minami, Kanako Tamura, Keisuke Iemoto, Taka ...
    2011 年 32 巻 2 号 p. 167-174
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    The mass of pancreatic β-cells is maintained throughout lifetime to control blood glucose levels. Although the major mechanism of the maintenance of β-cell mass after birth is thought to be selfreplication of pre-existing β-cells, it is possible that pancreatic β-cells are also generated from non-β-cells. Here, we address this issue by using the inducible Cre/loxP system to trace β-cells. We generated Ins2-CreERT2/R26R-YFP double knock-in mice, in which pancreatic β-cells can be labeled specifically and permanently upon injection of the synthetic estrogen analog tamoxifien, and then traced the β-cells by pulse and chase experiment in several different conditions. When β-cells were labeled in adults under physiological and untreated conditions, the frequency of the labeling (labeling index) was not altered significantly throughout the 12-month experimental period. In addition, the labeling index was not changed after ablation of β-cells by streptozotocin treatment. However, when tamoxifen was injected to pregnant mothers just before they gave birth, the labeling index in the neonates was decreased significantly around weaning, suggesting that β-cells are generated from non-β-cells. These results indicate that various mechanisms are involved in the maintenance of β-cells after birth, and that the present system using knock-in mice is useful for investigation of β-cell fate.
  • Kazunari Sato, Toshihiko Kawamura, Satoshi Yamagiwa
    2011 年 32 巻 2 号 p. 175-180
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Obese individuals have an increased risk of developing depression. This study aimed to determine whether the “Senobi” breathing exercise (SBE), a stretching-breathing exercise that we have established, could relieve depression, especially in obese women. Forty premenopausal women, aged 40 to 49 years, participated in the present study. Twenty were healthy, and the other 20 were obese (body mass index > 25 and body fat > 30%) and in a depressive state (OWD). Sympathetic nerve activity determined by analyzing heart rate variability, and the hormone levels in the urine were investigated before and 30 min after one minute of SBE. The relative proportion of sympathetic nerve activity among healthy women in the daytime was 79.2 &plsumn; 2.3%, whereas that in OWD group was 30.4 ± 1.9%. After one minute of SBE, significant up-regulation of sympathetic nerve activity and increased concentrations of catecholamines, estradiol, and growth hormone (all P values < 0.001) were observed in OWD group. After 30 days of SBE, the sympathetic nerve activity and hormone levels had recovered in OWD group, and the depressive state, as evaluated by the Hamilton Depression Scale, had ameliorated. The “Senobi” breathing exercise was found to be effective for amelioration of depression in obese women possibly through up-regulation of sympathetic nerve activity and hormone secretion.
Communication
  • Momoe Iwami, Takahiko Shiina, Haruko Hirayama, Yasutake Shimizu
    2011 年 32 巻 2 号 p. 181-185
    発行日: 2011年
    公開日: 2011/05/03
    ジャーナル フリー
    Zingerone, a pungent component of ginger, may exert beneficial therapeutic effects on hypermotilityinduced diarrhea because it has the ability to inhibit contractions of colonic smooth muscles. However, the pungency is undesirable for possible therapeutic use. The purpose of this study was to examine effects of zingerol, a non-pungent analogue of zingerone, in rats. Colonic motility in vivo was evaluated by measuring intraluminal pressure changes and expelled fluid volume from the colon in anesthetized rats. Mechanical contractile activities of isolated colonic segments were also recorded. Intracolonic administration of zingerol attenuated colonic motility in vivo without affecting blood pressure and heart rate in a manner similar to that of zingerone. Zingerol also inhibited spontaneous contractile movements in isolated colonic segments, suggesting that zingerol directly acts on the colon. Zingerol had no effect on jejunal motility, although zingerone showed an inhibitory effect to the jejunum. These findings suggest that zingerol can inhibit colonic motility without adverse effects on small intestinal motility and the cardiovascular system. The non-pungent property of zingerol will be useful as an oral or suppository medicine for treating diarrhea and other gastrointestinal disorders.
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