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931.
J H Hochman Y Shimizu R DeMars M Edidin 《Journal of immunology (Baltimore, Md. : 1950)》1988,140(7):2322-2329
We prepared single-labeled FITC derivatives of beta-2-microglobulin (b2m) and examined their interactions with class I MHC Ag H chains on living cells. Human b2m was reacted with FITC under mild conditions and separated by hydroxylapatite chromatography into three peaks containing single labeled derivatives of b2m peaks A, B, and C, and a peak containing the unmodified protein. The three fluorescent derivatives labeled the surfaces of cells bearing class I MHC Ag. The labeling was specific for class I MHC Ag as indicated by failure to label cells in the presence of excess unlabeled b2m and failure to label the HLA-negative cell lines Daudi and 721.221. Mouse cells labeled with fluorescent human b2m were recognized by mAb to the class I MHC Ag and by virus-restricted cytotoxic T lymphocytes, suggesting that labeling with the fluorescent b2m does not significantly alter the structure of class I MHC Ag or impair their ability to present viral antigens to cytotoxic T lymphocytes. We determined the kinetic and equilibrium binding parameters for the fluorescent b2m derivatives associating with the class I H chains of mouse and human cells. Peaks B and C exhibited biphasic binding to the mouse lymphoma cells EL-4(G-CSA-) (Kd1 = 1 x 10(-9) M; K2 = 1.5 to 3.0 x 10(-8) M whereas peak A bound to a small number of low affinity binding sites. In contrast to the biphasic binding observed with EL-4(G-CSA-), only monophasic binding was observed for peak C binding to RDM4 cells. Biphasic binding was also observed with the human B cell line LCL 721. Analysis of a series of LCL 721 class I MHC loss mutants and gene transferents revealed that the heterogeneity in binding is due to differences in the affinity of different class I encoded H chains for b2m. 相似文献
932.
Yuji Shimizu Mio Nakazato Takaharu Sekita Koichiro Kadota Kazuhiko Arima Hironori Yamasaki Hisashi Goto Satoshi Shirahama Noboru Takamura Kiyoshi Aoyagi Takahiro Maeda 《Journal of physiological anthropology》2013,32(1):19
Background
Previous studies have reported an inverse association between height and risk of cardiovascular disease. However, evidence is limited for the association between risk of atherosclerosis and height. Further, although the association between atherosclerosis and body mass index (BMI) is reportedly positive, there have been no reports of studies on associations between height and atherosclerosis in relation to BMI.Methods
We conducted a cross-sectional study of Japanese men aged 30 to 89 years undergoing general health check-ups.Results
Of the 1,337 men, 312 were diagnosed with carotid atherosclerosis (carotid intima-media thickness (CIMT) ≥ 1.1 mm), but no significant association was found between height and carotid atherosclerosis for the entire study group. Stratification by BMI status of those analytical findings disclosed a significant inverse association between height and carotid atherosclerosis among overweight (BMI ≥ 25 kg/m2) but not among non-overweight (BMI < 25 kg/m2) men. The classical cardiovascular risk factors-adjusted odds ratio (OR) and 95% confidence interval (CI) of carotid atherosclerosis for an increment of one SD (standard deviation) in height (6.70 cm) were 0.71 (0.54 to 0.94) for overweight (BMI ≥ 25 kg/m2) and 1.05 (0.87 to 1.27) for non-overweight (BMI < 25 kg/m2) men.Conclusion
Independent from classical cardiovascular risk factors, height was found to be inversely associated with carotid atherosclerosis for overweight but not for non-overweight men. 相似文献933.
Tagaya Y Osaki A Miura A Okada S Ohshima K Hashimoto K Yamada M Satoh T Shimizu H Mori M 《Protein and peptide letters》2012,19(9):997-1004
Nucleobindin-2 is a 420 amino acid EF-hand Ca2+ binding protein that can be further processed to generate an 82 amino terminal peptide termed Nesfatin-1. To examine the function of secreted Nucleobindin-2 in adipocyte differentiation, cultured 3T3-L1 cells were incubated with either 0 or 100 nM of GST, GST-Nucleobindin-2, prior to and during the initiation of adipocyte differentiation. Nucleobindin-2 treatment decreased neutral lipid accumulation (Oil-Red O staining) and expression of several marker genes for adipocyte differentiation (PPARγ, aP2, and adipsin). When Nucleobindin- 2 was constitutively secreted into cultured medium, cAMP content and insulin stimulated CREB phosphorylation were significantly reduced. On the other hand, intracellularly overexpressed Nucleobindin-2 failed to affect cAMP content and CREB phosphorylation. Taken together, these data indicate that secreted Nucleobindin-2 is a suppressor of adipocyte differentiation through inhibition of cAMP production and insulin signal. 相似文献
934.
Mitsui N Suzuki N Koyama Y Yanagisawa M Otsuka K Shimizu N Maeno M 《Life sciences》2006,79(6):575-583
Bone matrix turnover is regulated by matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), and the plasminogen activation system, including tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1). We previously demonstrated that 1.0g/cm(2) of compressive force was an optimal condition for inducing bone formation by osteoblastic Saos-2 cells. Here, we examined the effect of mechanical stress on the expression of MMPs, TIMPs, tPA, uPA, and PAI-1 in Saos-2 cells. The cells were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum and with or without continuously compressive force (0.5-3.0g/cm(2)) for up to 24h. The levels of MMPs, TIMPs, uPA, tPA, and PAI-1 gene expression were estimated by determining the mRNA levels using real-time PCR, and the protein levels were determined using ELISA. The expression levels of MMP-1, MMP-2, MMP-14, and TIMP-1 markedly exceeded the control levels at 1.0g/cm(2) of compressive force, whereas the expression levels of MMP-3, MMP-13, TIMP-2, TIMP-3, TIMP-4, tPA, uPA, and PAI-1 markedly exceeded the control levels at 3.0g/cm(2). These results suggest that mechanical stress stimulates bone matrix turnover by increasing these proteinases and inhibitors, and that the mechanism for the proteolytic degradation of bone matrix proteins differs with the strength of the mechanical stress. 相似文献
935.
Kazutoyo Osoegawa Rie Susukida Saishi Okano Jun Kudoh Shinsei Minoshima Nobuyoshi Shimizu Pieter J. de Jong Juergen Groet Jane Ives Hans Lehrach Dean Nizetic Eiichi Soeda 《Genomics》1996,32(3):375
The major phenotypic features of Down syndrome have been correlated with partial trisomies of chromosome 21, allowing us to define the candidate gene region to a 4-Mb segment on the 21q22.2 band. We present here a high-resolution physical map with megabase-sized cosmid/PAC contigs. This ordered clone library has provided unique material for the integration of a variety of mappable objects, including exons, cDNAs, restriction sites, etc. Furthermore, our results have exemplified a strategy for the completion of the chromosome 21 map to sequencing. 相似文献
936.
937.
Structure of human holocarboxylase synthetase gene and mutation spectrum of holocarboxylase synthetase deficiency 总被引:4,自引:0,他引:4
Xue Yang Yoko Aoki Xue Li Osamu Sakamoto Masahiro Hiratsuka Shigeo Kure Sepidh Taheri Ernst Christensen Koji Inui Mitsuru Kubota Miki Ohira Misao Ohki Jun Kudoh Kazuhiko Kawasaki Kazunori Shibuya Ai Shintani Shuichi Asakawa Shinsei Minoshima Nobuyoshi Shimizu Kuniaki Narisawa Yoichi Matsubara Yoichi Suzuki 《Human genetics》2001,109(5):526-534
Holocarboxylase synthetase (HLCS) is an enzyme that catalyzes the incorporation of biotin into apo-carboxylases, and its deficiency causes biotin-responsive multiple carboxylase deficiency. The reported sequences of cDNA for human HLCS from liver, lymphocyte, and KG-1 myeloid cell lines differ at their 5' regions. To elucidate variations of the human HLCS mRNA and longer 5' cDNA ends, we performed screening of the human liver cDNA library and rapid amplification of the cDNA ends (RACE). Our results suggest the existence of three types of HLCS mRNA that start at different exons. The first type starts at exon 1, and the second type starts at exon 3, and both are found in various human tissues. The third type, corresponding to the cDNA from the KG-1 cell, starts at exon 2 of the HLCS gene. Various splicing patterns from exons 3-6 were also observed. None of the variations of cDNA found created a new initiation codon. Mutation screening from exons 6-14, therefore, was sufficient to detect amino acid changes in HLCS in patients. Our direct sequencing strategy for screening mutations in the HLCS gene revealed mutations in five Japanese patients and seven non-Japanese patients. Our analyses involving 12 Japanese and 13 non-Japanese patients and studies by others indicate that (1) there is no panethnically prevalent mutation; (2) the Arg508Trp, Gly581Ser, and Val550Met mutations are found in both Japanese and non-Japanese populations; (3) the IVS10+5G-->A mutation is predominant and probably a founder mutation in European patients; (4) the 655-656insA, Leu237Pro, and 780delG mutations are unique in Japanese patients; (5) the spectrum of the mutations in the HLCS gene may vary substantially among different ethnic groups. 相似文献
938.
939.
A methanol-utilizing bacterium, Protaminobacter ruber, formed a green pigment, when it was grown on 1,2-propanediol as a sole carbon and energy source. The pigment was identified as bacteriochlorophyll a by the absorption spectrum resembling the pigment from photosynthetic bacteria and by the exact stoichiometric relationship among the original pigment, the pigment treated to remove magnesium (bacteriopheophytin) and magnesium ion obtained from the pigment. Bacteriochlorophyll formation was stimulated by the exposure to light during the relatively early stage of the growth, while the continuous light exposure completely prevented the pigment formation. Aeration was also necessary for the pigment synthesis as well as the bacterial growth. Electron micrographs of thin section of P. ruber cells cultured in the intermittent light showed the probable existence of a chromatophore-like structure. 相似文献
940.
A new enzyme has been obtained in a crystalline state from the muscle of blue white dolphin. This enzyme resembles to methemoglobin reductase from erythrocyte with respect to (a) elution pattern of DEAE-Sephadex column chromatography, (b) absorption spectra, (c) molecular weight and (d) activity of reducing methemoglobin, metmyoglobin and ferric cytochrome c. However, distinct differences can be observed between two enzymes with regard to (a) sedimentation coefficient, (b) diffusion coefficient, (c) frictional ratio, (d) pH-mobility curve and (e) specific activity of reducing the above three substrates. It is advocated that enzyme is termed metmyoglobin reductase. 相似文献