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991.
A method for estimating torque-vector directions of shoulder muscles using surface EMGs 总被引:1,自引:0,他引:1
In this study, a new method is proposed to estimate the torque-vector directions of each shoulder muscle. The method is based on a multiple regression model that reconstructs shoulder torque, which is calculated from the hand force and posture, from the surface EMG of many muscles recorded simultaneously. The torque-vector directions of eleven shoulder muscles of four subjects were obtained at up to 30 different arm postures with this method. The mean confidence interval ( p< 0.05) of the estimated torque-vector direction of each subject was 7.7-10.6 degrees. The correlation coefficient between the measured shoulder torque and reconstructed shoulder torque was between 0.76-0.84. The results for majority of the muscles were in accordance with previous studies, and reasonable from the viewpoint of anatomy. The torque-vector directions of a muscle, which are estimated with this method, have more of a functional meaning than a pure anatomical or mechanical one. These indicate the direction of the shoulder torque accompanying the muscle activation for a normal shoulder action that involves the cooperative contraction of many muscles. 相似文献
992.
Kojima K Naruse Y Iijima N Wakabayashi N Mitsufuji S Ibata Y Tanaka M 《American journal of physiology. Regulatory, integrative and comparative physiology》2002,282(5):R1348-R1355
We investigated the responses of the hypothalamic-pituitary-adrenal (HPA) axis during experimental colitis induced by intracolonic administration of 2,4,6-trinitrobenzenesulfonic acid in the rat. On days 3 and 7 after induction of colitis, the corticotropin-releasing hormone (CRH) mRNA level in the parvocellular paraventricular nucleus (pPVN) of the hypothalamus was reduced, the plasma ACTH level remained at the basal level, and the plasma corticosterone (Cort) level was high. Induction of colitis on day 3 after adrenalectomy with Cort pellet replacement (ADX + Cort) resulted in a marked increase in CRH mRNA on day 7 after induction of colitis compared with noncolitic ADX + Cort animals. Pair feeding to match the food intake of the colitic animals resulted in no significant change in CRH mRNA in the pPVN, plasma ACTH, and Cort compared with healthy control animals. These findings indicated that CRH mRNA expression in the pPVN was inhibited by glucocorticoid feedback during this experimental colitis, and the decrease in food intake during colitis was not simply responsible for the expression of CRH mRNA. It is inferred that the HPA axis including the CRH level in the pPVN is altered in patients with inflammatory bowel disease. 相似文献
993.
994.
Murakami M Yoshihara K Shimbara S Lambeau G Gelb MH Singer AG Sawada M Inagaki N Nagai H Ishihara M Ishikawa Y Ishii T Kudo I 《The Journal of biological chemistry》2002,277(21):19145-19155
Here we report the cellular arachidonate (AA)-releasing function of group IIF secretory phospholipase A(2) (sPLA(2)-IIF), a sPLA(2) enzyme uniquely containing a longer C-terminal extension. sPLA(2)-IIF increased spontaneous and stimulus-dependent release of AA, which was supplied to downstream cyclooxygenases and 5-lipoxygenase for eicosanoid production. sPLA(2)-IIF also enhanced interleukin 1-stimulated expression of cyclooxygenase-2 and microsomal prostaglandin E synthase. AA release by sPLA(2)-IIF was facilitated by oxidative modification of cellular membranes. Cellular actions of sPLA(2)-IIF occurred independently of the heparan sulfate proteoglycan glypican, which acts as a functional adaptor for other group II subfamily sPLA(2)s. Confocal microscopy revealed the location of sPLA(2)-IIF on the plasma membrane. The unique C-terminal extension was crucial for its plasma membrane localization and optimal cellular functions. sPLA(2)-IIF expression was increased in various tissues from lipopolysaccharide-treated mice and in ears of mice with experimental atopic dermatitis. In human rheumatoid arthritic joints, sPLA(2)-IIF was detected in synovial lining cells, capillary endothelial cells, and plasma cells. These results suggest that sPLA(2)-IIF is a potent regulator of AA metabolism and participates in the inflammatory process under certain conditions. 相似文献
995.
Shinomiya A Shibata N Sakaizumi M Hamaguchi S 《The International journal of developmental biology》2002,46(5):711-717
In order to investigate the function of gonadal somatic cells in the sex differentiation of germ cells, we produced chimera fish containing both male (XY) and female (XX) cells by means of cell transplantation between blastula embryos in the medaka, Oryzias latipes. Sexually mature chimera fish were obtained from all combinations of recipient and donor genotypes. Most chimeras developed according to the genetic sex of the recipients, whose cells are thought to be dominant in the gonads of chimeras. However, among XX/XY (recipient/donor) chimeras, we obtained three males that differentiated into the donor's sex. Genotyping of their progeny and of strain-specific DNA fragments in their testes showed that, although two of them produced progeny from only XX spermatogenic cells, their testes all contained XY cells. That is, in the two XX/XY chimeras, germ cells consisted of XX cells but testicular somatic cells contained both XX and XY cells, suggesting that the XY somatic cells induced sex reversal of the XX germ cells and the XX somatic cells. The histological examination of developing gonads of XX/XY chimera fry showed that XY donor cells affect the early sex differentiation of germ cells. These results suggest that XY somatic cells start to differentiate into male cells depending on their sex chromosome composition, and that, in the environment produced by XY somatic cells in the medaka, germ cells differentiate into male cells regardless of their sex chromosome composition. 相似文献
996.
Sakai S Mantani N Kogure T Ochiai H Shimada Y Terasawa K 《Mediators of inflammation》2002,11(6):359-361
BACKGROUND: Influenza virus is a worldwide health problem with significant economic consequences. To study the gene expression pattern induced by influenza virus infection, it is useful to reveal the pathogenesis of influenza virus infection; but this has not been well examined, especially in vivo study. AIMS: To assess the influence of influenza virus infection on gene expression in mice, mRNA levels in the lung and tracheal tissue 48 h after infection were investigated by cDNA array analysis. METHODS: Four-week-old outbred, specific pathogen free strain, ICR female mice were infected by intra-nasal inoculation of a virus solution under ether anesthesia. The mice were sacrificed 48 h after infection and the tracheas and lungs were removed. To determine gene expression, the membrane-based microtechnique with an Atlas cDNA expression array (mouse 1.2 array II) was performed in accordance with the manual provided. RESULTS AND CONCLUSIONS: We focused on the expression of 46 mRNAs for cell surface antigens. Of these 46 mRNAs that we examined, four (CD1d2 antigen, CD39 antigen-like 1, CD39 antigen-like 3, CD68 antigen) were up-regulated and one (CD36 antigen) was down-regulated. Although further studies are required, these data suggest that these molecules play an important role in influenza virus infection, especially the phase before specific immunity. 相似文献
997.
998.
Tamamura H Hiramatsu K Miyamoto K Omagari A Oishi S Nakashima H Yamamoto N Kuroda Y Nakagawa T Otaka A Fujii N 《Bioorganic & medicinal chemistry letters》2002,12(6):923-928
A 14-residue peptide, T140, strongly inhibits the T-cell line-tropic HIV-1 (X4-HIV-1) infection, since this peptide functions as a specific antagonist against a chemokine receptor, CXCR4. T140 takes an antiparallel beta-sheet structure with a type II' beta-turn. In the present paper, we have designed and synthesized several T140 analogues, in which an (E)-alkene dipeptide isostere was inserted into the type II' beta-turn moiety, as a bridging study to develop nonpeptidic CXCR4 inhibitors. It has been proven that the turn region of T140 can be replaced by the above surrogate with the maintenance of strong anti-HIV activity. 相似文献
999.
Nakashima Y Shinzawa-Itoh K Watanabe K Naoki K Hano N Yoshikawa S 《Journal of bioenergetics and biomembranes》2002,34(2):89-94
The rotenone sensitivity of bovine heart NADH: coenzyme Q oxidoreductase (Complex I) depends significantly on coenzyme Q1 concentration. The rotenone-insensitive Complex I reaction in Q1 concentration range above 300 M indicates an ordered sequential mechanism with Q1 and reduced Q1 (Q1H2) as the initial substrate to bind to the enzyme and the last product to be released from the enzyme product complex, respectively. This is the case in the rotenone-sensitive reaction although both K
m and V
max values of the rotenone-insensitive reaction for Q1 are significantly higher than those of the rotenone-sensitive reaction (Nakashima et al., 2002, J. Bioenerg. Biomemb.
34, 11–19). This rigorous control mechanism between the nucleotide and ubiquinone binding sites strongly suggests that the rotenone-insensitive reaction is also physiologically relevant. 相似文献
1000.
Kanayama N Kimoto T Todo K Nishikawa Y Hikida M Magari M Cascalho M Ohmori H 《Journal of immunology (Baltimore, Md. : 1950)》2002,169(12):6865-6874
The quasi-monoclonal mouse has limited B cell diversity, whose major (approximately 80%) B cell Ag receptors are comprised of the knockin V(H) 17.2.25 (V(H)T)-encoded H chain and the lambda1 or lambda2 L chain, thereby being specific for 4-hydroxy-3-nitrophenylacetyl. The p-nitrophenylacetyl (pNP) was found to be a low affinity analog of nitrophenylacetyl. We examined affinity maturation of anti-pNP IgG by analyzing mAbs obtained from quasi-monoclonal mice that were immunized with this low affinity Ag. The results are: 1) Although V(H)T/lambda1 and V(H)T/lambda2 IgM were equally produced, V(H)T/lambda2 IgG almost exclusively underwent affinity maturation toward pNP. 2) A common mutation in complementarity-determining region 3 of V(H)T (T313A) mainly contributed to generating the specificity for pNP. 3) Because mutated V(H)T-encoded gamma-chains could form lambda1-bearing IgG in Chinese hamster ovary cells, apparent absence of V(H)T/lambda1 anti-pNP IgG may not be due to the incompatibility between the gamma-chains and the lambda1-chain, but may be explained by the fact that V(H)T/lambda1 B cells showed 50- to 100-fold lower affinity for pNP than V(H)T/lambda2 B cells. 4) Interestingly, a pNP-specific IgM mAb that shared common mutations including T313A with high affinity anti-pNP IgG was isolated, suggesting that a part of hypermutation coupled with positive selection can occur before isotype switching. Thus, even weak B cell receptor engagement can elicit an IgM response, whereas only B cells that received signals stronger than a threshold may be committed to an affinity maturation process. 相似文献