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991.
Shibue M Yoshiki M Miyazaki M Fujita I Osada S Yasuda S Nakamura H Hamasaki Y Kondo M Maeda H Kodama H Shimizu H 《Protein and peptide letters》2003,10(2):147-153
Formylpeptide receptors are well-characterized receptors which participate in host defense responses of neutrophils. We designed and synthesized chemotactic peptide analog with p-benzoylphenylalanine (Bpa) and biotin to probe structural and mechanistic aspects of peptide-receptor interaction. These peptides possess biological activities which were dependent upon spacer residue length of and Bpa position. The covalent photoaffinity label was detected by Streptavidine-blot, which was inhibited by the parent peptide. 相似文献
992.
993.
Kiviluoto T Watanabe S Hirose M Sato N Mustonen H Puolakkainen P Rönty M Ranta-Knuuttila T Kivilaakso E 《American journal of physiology. Gastrointestinal and liver physiology》2001,281(5):G1151-G1157
Effects of nitric oxide (NO) on gastric wound healing were investigated in primary rabbit gastric epithelial cell cultures. We analyzed the speed of cell migration, proliferation, and apoptosis after creating a round wound on the cell cultures. The monolayers were incubated with or without the NO donor sodium nitroprusside, oxatriazolimine 1,2,3,4-oxatriazolium, 5amino-3-(3,4-dichlorophenylchloride), or the peroxynitrite generator 3-morpholinosydnomine-N-ethylcarbamide. The possible role of cGMP as a second messenger of NO was investigated with 8-bromo-cGMP. The role of O2(-*) was evaluated using diethyldithiocarbamate and pyrogallol. The effects of superoxide dismutase and allopurinol were also investigated. NO inhibited the speed of cell migration and proliferation and induced cell apoptosis in a dose- and time-dependent manner. The effects were augmented with O2(-*) generators and ameliorated by O2-(8) scavengers, whereas cGMP had no significant effect on wound healing. NO donors retard gastric wound healing by inhibiting migration and proliferation and inducing cell apoptosis. These effects do not seem to be mediated via cGMP, but O2(-*). or peroxynitrites may be involved. 相似文献
994.
995.
Sasaki N Sato T Marbán E O'Rourke B 《American journal of physiology. Heart and circulatory physiology》2001,280(4):H1882-H1888
We tested whether close coupling exists between mitochondria and sarcolemma by monitoring whole cell ATP-sensitive K(+) (K(ATP)) current (I(K,ATP)) as an index of subsarcolemmal energy state during mitochondrial perturbation. In rabbit ventricular myocytes, either pinacidil or the mitochondrial uncoupler dinitrophenol (DNP), which rapidly switches mitochondria from net ATP synthesis to net ATP hydrolysis, had little immediate effect on I(K,ATP). In contrast, in the presence of pinacidil, exposure to 100 microM DNP rapidly activated I(K,ATP) with complex kinetics consisting of a quick rise [time constant of I(K,ATP) increase (tau) = 0.13 +/- 0.01 min], an early partial recovery (tau = 0.43 +/- 0.04 min), and then a more gradual increase. This DNP-induced activation of I(K,ATP) was reversible and accompanied by mitochondrial flavoprotein oxidation. The F(1)F(0)-ATPase inhibitor oligomycin abolished the DNP-induced activation of I(K,ATP). The initial rapid rise in I(K,ATP) was blunted by atractyloside (an adenine nucleotide translocator inhibitor), leaving only a slow increase (tau = 0.66 +/- 0.17 min, P < 0.01). 2,4-Dinitrofluorobenzene (a creatine kinase inhibitor) slowed both the rapid rise (tau = 0.20 +/- 0.01 min, P < 0.05) and the subsequent declining phase (tau = 0.88 +/- 0.19 min, P < 0.05). From single K(ATP) channel recordings, we excluded a direct effect of DNP on K(ATP) channels. Taken together, these results indicate that rapid changes in F(1)F(0)-ATPase function dramatically alter subsarcolemmal energy charge, as reported by pinacidil-primed K(ATP) channel activity, revealing cross-talk between mitochondria and sarcolemma. The effects of mitochondrial ATP hydrolysis on sarcolemmal K(ATP) channels can be rationalized by reversal of F(1)F(0)-ATPase and the facilitation of coupling by the creatine kinase system. 相似文献
996.
Comparison of oligosaccharide components derived from salivary mucin was performed between secretor and non-secretor individuals. Salivary mucin was collected from four secretors and three non-secretors having blood group type-A. Compositional analysis showed that the contents of galactose and N-acetylglucosamine in the non-secretor were higher than those in the secretor. The O-linked oligosaccharides obtained by treatment with alkaline borohydride were separated by gel filtration using Sephadex G-50. The results indicated that the size of the type-A active oligosaccharides from the secretor was similar to or smaller than that of the non-secretor. Ion-exchange chromatography showed that the secretors had strong type-A activities in both the neutral and acidic fractions but the non-secretors showed type-A activity mainly in the neutral fraction. These results suggest that compositional differences in blood group substances exist between secretors and non-secretors. 相似文献
997.
Sato S Taoda K Kawamura M Wakaba K Fukuchi Y Nishiyama K 《Journal of human ergology》2001,30(1-2):235-240
We recorded ambulatory electrocardiograms of 6 long distance truck drivers during their work period in order to observe the affect of autonomic nervous function and symptoms while doing their work. We also recorded their work patterns every minute. The RR50 value and the LFP/HFP ratio were calculated every two minutes based on R-R interval data. RR50 was significantly higher during taking naps than during other periods of work shifts, while, the LFP/HFP ratio showed significantly lower during taking naps than during other periods of work shifts. RR50 in the morning was significantly higher than that in the afternoon. On the contrary, the LFP/HFP ratio showed opposite tendency. Only on the times of driving, RR50 was significantly higher in the morning than that in the afternoon. On the other hand, the LFP/HFP ratio showed an opposite tendency. These results show that the parasympathetic nervous activities were more dominant than sympathetic nervous activities in the morning during the subjects were doing long distance truck driving including midnight work. Driving while in high parasympathetic nervous activity levels may add to cardiovascular stress and lead to drowsiness. And this may result in disrupted attention. It is necessary to decrease work time and improve working conditions of truck drivers working long-hour shifts. 相似文献
998.
Katsumata N Satoh M Mikami A Mikami S Nagashima-Miyokawa A Sato N Yokoya S Tanaka T 《Hormone research》2001,55(3):141-146
BACKGROUND: 17alpha-Hydroxylase/17,20-lyase deficiency is caused by a defect of P450c17 which catalyzes both 17alpha-hydroxylase and 17,20-lyase reactions in adrenal glands and gonads. RESULTS: In the present study, we analyzed the CYP17 gene in a Japanese patient with 17alpha-hydroxylase/17,20-lyase deficiency. The patient was a phenotypic girl and referred to us for right-sided inguinal hernia at the age of 4 years. Biopsy of the herniated gonad showed testicular tissue. The karyotype was 46,XY. At 6 years of age, hypertension was clearly recognized and the patient was diagnosed as having 17alpha-hydroxylase/17,20-lyase deficiency based on the clinical and laboratory findings. Analysis of the CYP17 gene revealed a compound heterozygous mutation. One mutation was an undescribed single nucleotide deletion at codon 247 in exon 4 (CTT to CT: 247delT) and the other was a missense mutation resulting in a substitution of His to Leu at codon 373 in exon 6 (CAC to CTC: H373L), which has been previously shown to abolish both 17alpha-hydroxylase and 17,20-lyase activities. The functional expression study of the 247delT mutant showed that this 247delT mutation completely eliminates both 17alpha-hydroxylase and 17,20-lyase activities. CONCLUSIONS: Together, these results indicate that the patient is a compound heterozygote for the mutation of the CYP17 gene (247delT and H373L) and that these mutations inactivate both 17alpha-hydroxylase and 17,20-lyase activities and give rise to clinically manifest 17alpha-hydroxylase/17,20-lyase deficiency. 相似文献
999.
Miyagi N Sato K Rong Y Yamamura S Katagiri H Kobayashi K Iwata H 《Bioelectromagnetics》2000,21(2):112-121
After pulsed exposure of Dunn osteosarcoma cells (nonresistant cells) to Adriamycin (ADR) at increasing concentrations and single-cell cloning of surviving cells, ADR-resistant cells were obtained. These resistant cells expressed P-glycoprotein and had resistance more than 10 times that of their nonresistant parent cells. Compared to the nonresistant cells not exposed to pulsing electromagnetic fields (PEMF) in ADR-free medium, their growth rates at ADR concentrations of 0.01 and 0.02 micrograms/ml, which were below IC50, were 83.0% and 61.8%, respectively. On the other hand, in the nonresistant cells exposed to PEMF (repetition frequency, 10 Hz; rise time, 25 microsec, peak magnetic field intensity, 0.4-0.8 mT), the growth rate was 111.9% in ADR-free medium, 95.5% at an ADR concentration of 0.01 micrograms/ml, and 92.2% at an ADR concentration of 0.02 micrograms/ml. This promotion of growth by PEMF is considered to be a result of mobilization of cells in the non-proliferative period of the cell cycle due to exposure to PEMF. However, at ADR concentrations above the IC50, the growth rate tended to decrease in the cells not exposed to PEMF. This may be caused by an increase in cells sensitive to ADR resulting from mobilization of cells in the non-proliferative period to the cell cycle. The growth rate in the resistant cells exposed to PEMF was significantly lower than that in the non-exposed resistant cells at all ADR concentrations, including ADR-free culture (P=0.0114). Therefore, this study suggests that PEMF promotes the growth of undifferentiated cells but progressively suppresses the growth of more differentiated cells, i.e., PEMF controls cell growth depending on the degree of cell differentiation. This study also shows the potentiality of PEMF as an adjunctive treatment method for malignant tumors. 相似文献
1000.
Differential electron flow around photosystem I by two C(4)-photosynthetic-cell-specific ferredoxins 下载免费PDF全文
Kimata-Ariga Y Matsumura T Kada S Fujimoto H Fujita Y Endo T Mano J Sato F Hase T 《The EMBO journal》2000,19(19):5041-5050
In the C(4) plant maize (Zea mays L.), two ferredoxin isoproteins, Fd I and Fd II, are expressed specifically in mesophyll and bundle-sheath cells, respectively. cDNAs for these ferredoxins were introduced separately into the cyanobacterium Plectonema boryanum with a disrupted endogenous ferredoxin gene, yielding TM202 and KM2-9 strains expressing Fd I and Fd II. The growth of TM202 was retarded under high light (130 micromol/m(2)/s), whereas KM2-9 grew at a normal rate but exhibited a nitrogen-deficient phenotype. Measurement of photosynthetic O(2) evolution revealed that the reducing power was not efficiently partitioned into nitrogen assimilation in KM2-9. After starvation of the cells in darkness, the P700 oxidation level under far-red illumination increased significantly in TM202. However, it remained low in KM2-9, indicating an active cyclic electron flow. In accordance with this, the cellular ratio of ATP/ADP increased and that of NADPH/NADP(+) decreased in KM2-9 as compared with TM202. These results demonstrated that the two cell type-specific ferredoxins differentially modulate electron flow around photosystem I. 相似文献