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1.
Yusuke Nakamura Michio Ogawa Takahiro Nishide Mitsuru Emi Goro Kosaki Seiichi Himeno Kenichi Matsubara 《Gene》1984,28(2):263-270
The nucleotide sequences of the cloned human salivary and pancreatic α-amylase cDNAs correspond to the continuous mRNA sequences of 1768 and 1566 nucleotides, respectively. These include all of the amino acid coding regions. Salivary cDNA contains 200 bp in the 5′-noncoding region and 32 in the 3′-noncoding region. Pancreatic cDNA contains 3 and 27 bp of 5′- and 3′-noncoding regions, respectively. The nucleotide sequence humology of the two cDNAs is 96% in the coding region, and the predicted amino acid sequences are 94% homologous.Comparison of the sequences of human α-amylase cDNAs with those previously obtained for mouse α-amylase genes (Hagenbuchle et al., 1980; Schibler et al., 1982) showed the possibility of gene conversion between the two genes of human α-amylase. 相似文献
2.
Junko Maeda Charles R. Yurkon Yoshihiro Fujii Hiroshi Fujisawa Sayaka Kato Colleen A. Brents Mitsuru Uesaka Akira Fujimori Hisashi Kitamura Takamitsu A. Kato 《PloS one》2015,10(12)
When energetic particles irradiate matter, it becomes activated by nuclear reactions. Radioactivation induced cellular effects are not clearly understood, but it could be a part of bystander effects. This investigation is aimed at understanding the biological effects from radioactivation in solution induced by hadron radiation. Water or phosphate buffered saline was activated by being exposed to hadron radiation including protons, carbon- and iron-ions. 1 mL of radioactivated solution was transferred to flasks with Chinese hamster ovary (CHO) cells cultured in 5 mL of complete media. The induction of sister chromatid exchanges (SCE) was used to observe any increase in DNA damage responses. The energy spectrum and the half-lives of the radioactivation were analyzed by NaI scintillation detector in order to identify generated radionuclides. In the radioactivated solution, 511 keV gamma-rays were observed, and their half-lives were approximately 2 min, 10 min, and 20 min. They respectively correspond to the beta+ decay of 15O, 13N, and 11C. The SCE frequencies in CHO cells increased depending on the amount of radioactivation in the solution. These were suppressed with a 2-hour delayed solution transfer or pretreatment with dimethyl sulfoxide (DMSO). Our results suggest that the SCE induction by radioactivated solution was mediated by free radicals produced by the annihilated gamma-rays. Since the SCE induction and DMSO modulation are also reported in radiation-induced bystander effects, our results imply that radioactivation of the solution may have some contribution to the bystander effects from hadron radiation. Further investigations are required to assess if radioactivation effects would attribute an additional level of cancer risk of the hadron radiation therapy itself. 相似文献
3.
Yukiji Shimojima Hiroshi Hayashi Tadaaki Ooka Mitsuru Shibukawa 《Bioscience, biotechnology, and biochemistry》2013,77(7):1823-1829
Two potent gastroprotective substances against experimental gastric ulcers in rats induced by stress and five of their analogues were isolated from the culture broth of bacterial strain AI-77 which was classified taxonomically as Bacillus pumilus. Physico-chemical properties and pharmacological activities of the seven compounds were examined and compared with each other. 相似文献
4.
Genetic linkage between lipoprotein(a) phenotype and a DNA polymorphism in the plasminogen gene 总被引:12,自引:0,他引:12
D T Drayna R A Hegele P E Hass M Emi L L Wu D L Eaton R M Lawn R R Williams R L White J M Lalouel 《Genomics》1988,3(3):230-236
Coronary heart disease risk correlates directly with plasma concentrations of lipoprotein(a) (Lp(a)), a low-density lipoprotein-like particle distinguished by the presence of the glycoprotein apolipoprotein(a) (apo(a)), which is bound to apolipoprotein B-100 (apoB-100) by disulfide bridges. Size isoforms of apo(a) are inherited as Mendelian codominant traits and are associated with variations in the plasma concentration of lipoprotein(a). Plasminogen and apo(a) show striking protein sequence homology, and their genes both map to chromosome 6q26-27. In a large family with early coronary heart disease and high plasma concentrations of Lp(a), we found tight linkage between apo(a) size isoforms and a DNA polymorphism in the plasminogen gene; plasma concentrations of Lp(a) also appeared to be related to genetic variation at the apo(a) locus. We found free recombination between the same phenotype and alleles of the apoB DNA polymorphism. This suggests that apo(a) size isoforms and plasma lipoprotein(a) concentrations are each determined by genetic variation at the apo(a) locus. 相似文献
5.
The effects of phenobarbital (PB), 3-methylcholanthrene (MC), and alpha-naphthoflavone (alpha-NF) on the synthesis of drug-inducible forms of cytochrome P-450, P-450(PB-1), and P-450(MC-1), and sex-specific forms of cytochrome P-450, P-450(M-1), and P-450(F-1), in male and female rats were studied. Whereas P-450(PB-1) and P-450(MC-1) in liver microsomes were markedly induced in both sexes by treatment with PB and MC, respectively, the contents of P-450(M-1) and P-450(F-1) were significantly decreased by the treatments. alpha-NF, which is not a P-450 inducer, did not change the contents of sex-specific forms of cytochrome P-450. The translatable mRNAs of the P-450s were also determined by using an in vitro translation system. The mRNAs coding for P-450(PB-1) and P-450(MC-1) were increased by drug administrations. On the other hand, the mRNAs coding for P-450(M-1) and P-450(F-1) were transiently decreased by the drugs, and then returned to the normal levels. The time courses of the induction of the drug-inducible P-450s and the repression of the sex-specific P-450s showed no close correlation. alpha-NF had no effect on the synthesis of P-450(M-1) and P-450(F-1). We also found that the synthesis of P-450(M-1) in the livers of untreated rats showed no diurnal variations. 相似文献
6.
Noritsugu Yabe Yutaka Matsuya Isao Yamane Mitsuru Takada 《In vitro cellular & developmental biology. Plant》1986,22(7):363-368
Summary A newly developed, serum-free medium (NYSF-404) selects for antibody-producing hybridomas after fusion of antigen-sensitized
mouse spleen cells with myeloma cell lines P3-X63-Ag8-U1 (P3-U1), P3-X63-Ag8-6.5.3 (Ag8.653), or P3-NSI/1-Ag4-1 (NS-1). Without
the need for hypoxanthine-aminopterinthymidine (HAT) selection of hybrid cells, frequency of hybridoma formation in medium
NYSF-404 is higher (twice) than that in serum- and HAT-containing medium. Colonies developed upon limiting dilution in the
presence of the mortal parent myeloma cells in medium NYSF-404 and pure culture of antibody-secreting cells could be subsequently
established. The results suggest that fusions can be done in serum-free medium and that the clonal growth of hybridomas is
dependent on factors produced by parent myeloma cells under serum-free culture conditions. Such factors seem deficient in
serum- and HAT-containing medium or are masked by serum. 相似文献
7.
Transformation of L cells with virus thymidine kinase genes introduced by red cell-mediated microinjection 总被引:2,自引:0,他引:2
Takashi Iino Mitsuru Furusawa Iwao Furusawa Masuo Obinata 《Experimental cell research》1983,148(2):475-480
Fusion of red cell ghosts containing foreign materials with cells results in the introduction of the materials into the cells (red cell-mediated microinjection). Until now, 'two-step dialysis' has mainly been used for trapping proteins in the ghosts. Large-sized materials such as DNA, however, are rarely trapped in the ghosts, since the holes in the red cell membrane caused by osmotic shock are too small for such materials to pass through. In this study, we improved the trapping technique. Some of the Hind III fragments of lambda phage DNA as well as proteins could be trapped in the ghosts when the mixture of these materials and red cells were frozen at -80 degrees C for a short period followed by quick thawing. Red cell-mediated microinjection using ghosts containing plasmid pBR322 linked with a Herpes simplex viral thymidine kinase (tk) gene brought about transformation of tk-defective L cells, the efficiency of transformation was 1 out of 20 000-60 000 cells fused with the ghosts. 相似文献
8.
Effect of Ethanol on the Sodium and Potassium Conductances of the Squid Axon Membrane 总被引:8,自引:6,他引:2 下载免费PDF全文
The effects of ethanol on squid giant axons were studied by means of the sucrose-gap technique. The membrane action potential height is moderately reduced and the duration sometimes shortened by ethanol in sea water. Voltage clamp experiments showed that ethanol in sea water reduced the maximum membrane conductances for sodium (g'Na) and potassium (g'K). In experiments with multiple application of ethyl alcohol to the same spot of membrane, a reduction of g'Na to 82 per cent and of g'K to 80 per cent of their value in sea water was brought about by 3 per cent ethanol (by volume) while 6 per cent caused a decrease of g'Na to 59 per cent and of g'K to 69 per cent. Ethanol has no significant effect on the steady-state inactivation of gNa (as a function of conditioning membrane potential) or on such kinetic parameters as τh or the time course of turning on gi gNa and gK. It is concluded that ethanol mainly reduces gNa and gK in the Hodgkin-Huxley terminology. 相似文献
9.
Mitsuru Iwata Shoko Iwata Mark A. Everett Bryan B. Fuller 《In vitro cellular & developmental biology. Plant》1990,26(6):554-560
Summary A human foreskin organ culture system has been developed to study the response of human skin to hormonal stimulation. Foreskins
are maintained in culture on floating plastic supports which allows the epidermal surface to be exposed to air while the dermis
is bathed in nutrient medium. Both black and white human foreskins can be maintained in organ culture for at least 1 wk with
no change in the tissue structure or cell viability as determined by histochemical staining and by dopa reaction staining.
Tyrosinase activity in both black and white human foreskin cultures decays markedly during the first 2 d of culture to a new
steady state level which remains stable throughout the culture period. Both black and white foreskin cultures consistently
demonstrate 2- to 10-fold increases in tyrosinase activity when treated with theophylline (1 mM). Approximately 90% of all skin cultures examined showed an increase in enzyme activity when treated with this phosphodiesterase
inhibitor. Dibutyryl cAMP (0.1 mM) and [Nle4, D-phe7]-alpha MSH (10−8
M), were also found to markedly stimulate tyrosinase activity in some skin cultures, whereas alpha-MSH and prostaglandin E1 produced only an inconsistent and small increase in the activity of the enzyme. Histamine (1 μM), vitamin D3 (1 μM), and retinoic acid (1μM) failed to stimulate tyrosinase activity in either white or black foreskin cultures. This hormone-responsive organ culture
system can be utilized to characterize the molecular processes responsible for the regulation of tyrosinase and pigmentation
in human skin.
This work was supported by a research contract from the Oklahoma Center for the Advancement of Science and Technology (OCAST)
and by a research grant from the Presbyterian Health Foundation. 相似文献
10.
John O. Hui John Le Viswanatham Katta Robert Rosenfeld Michael F. Rohde Mitsuru Haniu 《Journal of Protein Chemistry》1996,15(4):351-358
Human neurotrophin-3 (NT-3) is a member of the nerve growth factor (NGF) family of neurotrophic factors, and the recombinant protein is being developed as a therapeutic for neurodegenerative diseases. The final product purity and lot-to-lot variation are monitored routinely by peptide mapping. However, only the N-terminal region of NT-3 was susceptible to proteolysis under native conditions. Complete digestion required that the protein be chemically modified by reduction and S-alkylation prior to proteolysis. Complete proteolytic degradation of the protein was achieved simply by an intial denaturation of NT-3 in 6 M guanidinium chloride (pH 6) for 2 hr at 37°C, followed by a tenfold dilution with the digestion buffer (0.1 M Tris-HCl, 1 mM CaCl2 at pH 7.0) and immediate addition of chymotrypsin at 1% by weight. Direct comparison of the peptide map with an identical aliquot that had been reduced and alkylated also allowed the establishment of the cystine linkages present in NT-3: Cys14 to Cys79, Cys57 to Cys108, and Cys67 to Cys110. This disulfide structure is homologous to the NGF family of neurotrophic factors. 相似文献