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991.
Taku Fujiwara Yutaka Terao Tomonori Hoshino Shigetada Kawabata Takashi Ooshima Shizuo Sobue Shigenobu Kimura Shigeyuki Hamada 《FEMS microbiology letters》1998,161(2):331-336
Three glucosyltransferase (GTase) genes (gtfB, gtfC and gtfD) were cloned and sequenced from clinically isolated strains of Streptococcus mutans MT8148 (serotype c), MT4239 (c), MT4245 (e), MT4467 (e) and MT4251 (f), respectively. Comparison of the gtf genes revealed that interstrain difference of gtfB and gtfD was limited, while gtfC showed significant interstrain variations. Similar to gtfB and gtfD, gtfC possessed five direct repeats composed of homologous unit in the carboxyl-terminal portion. The repeating unit consisted of 63–65 amino acid residues and is responsible for glucan binding. The gtfC gene from S. mutans MT4245 lacked the fourth unit. Multiple alignment with the gtf sequence of strain GS-5 (c) revealed several changes in these gtf genes due to frameshift mutations. The peptides encoded by the gtfB, gtfC and gtfD genes of GS-5 were 1, 80, and 32 amino acid residues shorter than those of the test strains except strain MT4245. 相似文献
992.
M. Kato Toshiyuki Kimura Changqing Lin Aiko Ito Soichi Kodama Tateki Morikawa Takashi Soga Kiyoshi Hayasaka 《Human genetics》1999,104(4):341-344
The doublecortin (DCX) gene was recently found to be involved in patients with X-linked lissencephaly and subcortical band
heterotopia or double cortex syndrome. We have studied the coding regions of the DCX gene in 11 Japanese patients with cortical
dysplasia and have identified three different mutations (R186C in exon 3, R272X and R303X in exon 5) in four sporadic female
cases. R272X, which has been detected in two unrelated cases, is a novel mutation. Although the number of cases studied remains
limited, exon 5 may be a common mutational site in Japanese patients in contrast to many previus reports concerning exons
2 and 3.
Received: 28 October 1998 / Accepted: 26 February 1999 相似文献
993.
T Shibasaki K Moroi M Nishiyama J Zhou A Sakamoto T Masaki K Ito T Haga S Kimura 《Biochemistry and molecular biology international》1999,47(4):569-577
The role of phosphorylation of the C-terminal tail of endothelin B receptor (ETBR) in agonist-induced desensitization was investigated, using a mutant lacking C-terminal 40 amino acids (delta 40 ETBR). In cells expressing the wild type or delta 40 ETBR, ET-1 caused rapid desensitization of calcium responses. The wild type ETBR was phosphorylated by biotinylated ET-1, and the phosphorylation was markedly enhanced by coexpression with G protein-coupled receptor kinase 2 (GRK2). However, delta 40 ETBR was not phosphorylated regardless of coexpression with GRK2. On the other hand, ET-1-induced IP3 formation in these cells was decreased by coexpression with GRK2 or catalytically inactive Lys220Arg GRK2 to the similar extent. The present study demonstrates the presence of phosphorylation-independent desensitization mechanism in delta 40 ETBR and suggests that GRK2 might play a role other than that as a kinase. 相似文献
994.
Increased expression of inducible nitric oxide synthase and peroxynitrite in Helicobacter pylori gastric ulcer. 总被引:2,自引:0,他引:2
A A Sakaguchi S Miura T Takeuchi R Hokari M Mizumori H Yoshida H Higuchi M Mori H Kimura H Suzuki H Ishii 《Free radical biology & medicine》1999,27(7-8):781-789
The role of nitric oxide in ulcer formation remains unknown. Accordingly, we assessed local expression of inducible nitric oxide synthase (NOS) and nitration of tyrosine as an indicator of peroxynitrite formation in patients with Helicobacter pylori (HP)-associated gastric ulcers compared with HP-negative ulcers. Biopsy specimens were taken from the ulcer margin and from an area remote from the ulcer portion. Inducible NOS, nitrotyrosine, and macrophage immunoreactivity were assessed immunohistochemically using a labeled streptavidin-biotin method. In HP-positive gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity was frequently observed at active ulcer margins, sometimes in surface epithelial cells as well as in the lamina propria. Occasionally, inducible NOS and nitrotyrosine reactivity were found in areas remote from the lesion in cases of HP-positive ulcer and HP-related gastritis. Macrophages accumulated significantly in the margin of HP-positive ulcers. In HP-negative gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity also were frequent at the ulcer margin, but no significant immunoreactivity was observed at a distance. HP eradication caused significant attenuation in inducible NOS and macrophage immunoreactivity. In conclusion, nitric oxide and peroxynitrite formation is increased in HP-infected gastric mucosa, suggesting that HP promotes nitric oxide stress. 相似文献
995.
Nobuo Hoshino Takahide Kimura Akira Yamaji Takashi Ando 《Free radical biology & medicine》1999,27(11-12)
In the presence of a nonlethal concentration of Cu(II), washed Escherichia coli ATCC11775 cells were killed by (-)-epigallocatechin (EGC) and (-)-epicatechin (EC). Cell killing was accompanied by a depletion in both the ATP and potassium pools of the cells, but the DNA double strand was not broken, indicating that the bactericidal activity of catechins in the presence of Cu(II) results from damage to the cytoplasmic membrane. Induction of endogenous catalase in E. coli cells increased their resistance to being killed by the combination of catechins and Cu(II). In all cases studied, EGC and EC with Cu(II) were found to generate hydrogen peroxide, but its concentration was too low to account for the bactericidal activity. The bactericidal activity of EGC in the presence of Cu(II) was completely suppressed by ethylenediaminetetraacetate, bathocuproine, catalase, superoxide disumutase (SOD), heated catalase, and heated SOD, but not by dimethyl sulfoxide. When catalase, either heated or unheated, was added to the cells incubated with EGC in the presence of Cu(II), it completely inhibited further killing of the cells. These findings suggest that recycling redox reactions between Cu(II) and Cu(I), involving catechins and hydrogen peroxide on the cell surface, must be important in the mechanism of the killing. 相似文献
996.
Y Kimura Y Araki A Takenaka K Igarashi 《Bioscience, biotechnology, and biochemistry》1999,63(5):799-804
The preventive effects of nasunin (delphinidin-3-[4-p-coumaroyl-rhamnosyl(1-->6)glucosid e]-5-glucoside) on paraquat-induced oxidative stress were determined in rats. Decreased food intake and body weight gain and increased lung weight by feeding the rats a diet containing paraquat were clearly suppressed by supplementing nasunin to the paraquat diet. Paraquat feeding increased the concentration of thiobarbituric acid-reactive substances (TBARS) in liver lipids and the atherogenic index, and decreased the liver triacylglycerol level. These effects were also suppressed by supplementing nasunin to the paraquat diet. In addition, catalase activity in the liver mitochondrial fraction was markedly decreased by feeding the paraquat diet, this decrease being partially suppressed by supplementing the paraquat diet with nasunin. These results suggest that nasunin acted preventively against the oxidative stress in vivo that may have been due to active oxygen species formed through the action of paraquat. 相似文献
997.
Toshihiko Kimura Masataka Watanabe Kunio Kohata Ryuichi Sudo 《Journal of applied phycology》1999,11(3):301-311
The ecological advantage of diel vertical migration on the nutrition and accumulation of Chattonella antiqua, which is one
of the dominant red-tide forming phytoplankton species in the Seto Inland Sea of Japan, was examined using a large axenic
culture tank, in which vertical stratification of salinity, temperature and nutrients was maintained, analogous to natural
conditions observed when red tides occur. C. antiqua was capable of migrating through very sharp salinity and temperature
gradients. At night the species migrated to the deep nutrient-rich water and assimilated nutrients. During the daytime it
migrated to the nutrient-depleted surface water and used the accumulated nutrients for photosynthesis. Nitrogen uptake was
synchronized with phosphate uptake. 31P-NMR spectroscopy during the migration experiment revealed that C. antiqua has the capability of nocturnal phosphate uptake
in the deep nutrient-rich water, but no capability of synthesizing polyphosphate, which was considered to be the intracellular
phosphate pool. These findings were compared with those reported for another raphidophycean, Heterosigma akashiwo. Although
both species carry out vertical migration and nocturnal nutrient uptake, only H. akashiwo has the capability of making an
intracellular polyphosphate pool.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
998.
Regional lymph node lymphocytes from five patients with primary lung cancer were analyzed for subset composition, and exposed
in vitro to the polyclonal human B cell mitogen Staphylococcus aureus Cowan I (SACI) or the murine B cell mitogen lipopolysaccharide
(LPS) and then fused with mouse myeloma cells for investigation at the clonal level of their antibody (Ab) production and
its statistical relation to the original subset composition. No correlation was found between the proportion of CD19+, CD23+,
or CD3+ cells in the lymphocyte sample prior to its exposure to either SACI or LPS, and the Ab production efficiency, defined
as the ratio of the number of Ab producing wells to the total number of proliferating wells. For lymphocytes exposed to LPS,
however, a strong correlation (r = 0.931, p = 0.02) was observed between the Ab production efficiency and the ratio of CD8+
to CD3+ cells (CD8/CD3) in the original sample at least within the ranges studied (CD8/CD3 = 0.216–0.288). For those exposed
to SACI, no correlation was found between the Ab production efficiency and the CD8/CD3 ratio (r = 0.881, p = 0.12) or the
proportion of CD8+ cells (r = 0.808, p = 0.19) in the original sample. These results suggest that the repertoire of B cells
responsive to LPS is different at least in part from the repertoire responsive to SACI and that the ratio CD8/CD3 could serve
as a practical predictor for Ab production by human lymphocytes stimulated with LPS.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
999.
Yusuke Takeuchi Hideyuki Yamamoto Kazuya Matsumoto Takemi Kimura Shoichi Katsuragi Taihei Miyakawa Eishichi Miyamoto 《Journal of neurochemistry》1999,72(2):815-825
Abstract : To examine the physiological roles of the δ subunit of Ca2+ /calmodulin-dependent protein kinase ∥ (CaM kinase ∥δ) in brain, we examined the localization of CaM kinase ∥δ in the rat brain. A specific antibody to CaM kinase ∥δ1-δ4 isoforms was prepared by immunizing rabbits with a synthesized peptide corresponding to the unique carboxyl-terminal end of these isoforms. The prepared antibody did not recognize the α, β, and γ subunits, which were each overexpressed in NG108-15 cells. Immunoblot analysis on various regions and the nuclear fractions from rat brains suggested that some isoforms of CaM kinase ∥δ1-δ4 were abundant in the nucleus in the cerebellum. Total RNA from the cerebellum was analyzed by RT-PCR with a primer pair from variable domain 1 to variable domain 2. We detected the three PCR products δ3.1, δ3.4, and δ3 that contained the nuclear localization signal. These CaM kinase ∥δ3 isoforms were localized in the nuclei in transfected NG108-15 cells. Immunohistochemical study suggested the existence of these isoforms in the nuclei in cerebellar granule cells. These results suggest that CaM kinase ∥δ3 isoforms are involved in nuclear Ca2+ signaling in cerebellar granule cells. 相似文献
1000.