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排序方式: 共有538条查询结果,搜索用时 328 毫秒
1.
S Hayasaka T Shiono K Mizuno C Sasayama S Akiya Y Tanaka M Hayakawa Y Miyake N Ohba 《The British journal of ophthalmology》1986,70(8):612-614
We examined 15 Japanese patients who had gyrate atrophy of the choroid and retina with hyperornithinaemia. Their visual acuities fell to 0.2 or worse in the second or third decade of life. Myopia developed late in the first decade, and the refractions decreased to -10 or -15 dioptres at age 20. Tunnel vision developed at approximately age 20. Our results suggested that the visual functions of Japanese patients were worse in the third decade or later than similarly affected Finnish patients. 相似文献
2.
Tomohiko Ai M. Horie Kazuhiko Obayashi Shigetake Sasayama 《Pflügers Archiv : European journal of physiology》1998,436(2):168-174
To examine mechanism(s) underlying the accentuated antagonism by angiotensin II (A-II) on twitch tension, we recorded L-type
Ca2+ currents (I
Ca,L) using conventional patch-clamp techniques in single, guinea-pig, ventricular myocytes. I
Ca,L was recorded by a step-pulse protocol after eliminating K+ conductances (internal Cs+ plus tetraethylammonium chloride and K+-free extracellular solution). A-II (100 nM) did not affect basal I
Ca,L, but inhibited I
Ca,L that had been enhanced (approximately 200% of control) by (ISO, isoproterenol 100 nM). The inhibitory action of A-II was
concentration dependent (concentration eliciting 50% inhibition 88±9 pM, n=41) and the ISO-enhanced component of I
Ca,L was completely blocked by A-II at concentrations above 10 nM. CV-11974 (500 nM), an A-II type-1 receptor (AT1) antagonist, prevented the inhibitory action of A-II. Pre-incubation with pertussis toxin (PTX) abolished the inhibitory
effect of A-II. A-II also inhibited the I
Ca,L enhanced by histamine (500 nM) and forskolin (1 μM), but failed to affect I
Ca,L enhanced by intracellular cyclic adenosine monophosphate (1 mM). The inhibitory action of A-II may therefore involve AT1 receptors/PTX-sensitive, guanine nucleotide-binding (G) proteins (Gi)/adenylate cyclase and partially explains the A-II-dependent
accentuated antagonism of inotropy. 相似文献
3.
T Hirozane A Matsumori Y Furukawa S Matsui Y Sato Y Matoba S Sasayama 《Clinical and experimental immunology》1995,102(1):186-191
Amrinone is a non-glycoside positive inotropic agent with an inhibitory effect on a cyclic adenosine monophosphate (AMP) phosphodiesterase isoenzyme. In the present study, we examined the immunosuppressive action of amrinone, since several other cyclic AMP-elevating agents have been shown to suppress T lymphocyte activation. First, the in vivo effects of amrinone were investigated. Oral amrinone treatment, at 40 mg/kg per day, significantly prolonged median cardiac allograft survival compared with non-treated controls (22.0 days versus 10.5 days, P < 0.01) when DBA/2 mouse hearts (H-2d) were heterotopically transplanted into C57B1/6 mice (H-2b). Histopathological examination showed that there was less prominent cellular infiltration in the amrinone-treated than in the non-treated allografts. Plasma amrinone concentrations of mice after a single oral dose of 40 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were done. The generation of specific cytotoxic T lymphocytes after mixed lymphocyte culture was significantly suppressed by addition of amrinone to the culture medium at 5 micrograms/ml. The production of IL-2 and the interferon-gamma during mixed lymphocyte culture was also suppressed by amrinone at 5 micrograms/ml. However, the level of intracellular cyclic AMP in mouse splenic lymphocytes was not affected significantly by the same dose of amrinone. In conclusion, amrinone has immunosuppressive actions at the therapeutic doses, and it may be a beneficial agent for therapy against acute cardiac allograft rejection. 相似文献
4.
Sasayama T Marumoto T Kunitoku N Zhang D Tamaki N Kohmura E Saya H Hirota T 《Genes to cells : devoted to molecular & cellular mechanisms》2005,10(7):627-638
Aurora-A is a centrosomal serine-threonine kinase that regulates mitosis. Over-expression of Aurora-A has been found in a wide range of tumors and has been implicated in oncogenic transformation. However, how Aurora-A over-expression contributes to promotion of carcinogenesis remains elusive. Immunohistochemical analysis of breast tumors revealed that over-expressed Aurora-A is not restricted to the centrosomes but is also found in the cytoplasm. This over-expressed Aurora-A appeared to be phosphorylated on Thr288, which is known to be required for its enzymatic activation. In analogy to Aurora-A's role in oocyte maturation and the early embryonic cell cycle, here we investigated whether ectopically over-expressed Aurora-A can similarly stimulate polyadenylation of mRNA in human somatic cultured cells by interacting with a human ortholog of cytoplasmic polyadenylation element binding protein, h-CPEB. In vitro experiments revealed that Aurora-A binds directly to, and phosphorylates, h-CPEB. We found that polyadenylation of mRNA tails of cyclin B1 and Cdk1 was synergistically stimulated when Aurora-A and h-CPEB were over-expressed, and they were further promoted in the presence of an Aurora-A activator Ajuba. Our results suggest a function of ectopically over-expressed Aurora-A that might be relevant for carcinogenesis. 相似文献
5.
Effect of the anticomplementary agent, K-76 monocarboxylic acid, on experimental immune complex glomerulonephritis in rats. 下载免费PDF全文
H Iida K Izumino M Asaka M Takata Y Mizumura S Sasayama 《Clinical and experimental immunology》1987,67(1):130-134
We examined the effect of the anticomplementary agent K-76 monocarboxylic acid (K-76COOH), which is known to inhibit C5 activity, on immune complex glomerulonephritis in rats. Bovine serum albumin (BSA) nephritis was induced in rats by subcutaneous immunization and daily intravenous administration of BSA. K-76COOH (30 mg/kg) was administered intraperitoneally twice daily for 4 weeks. It was shown that K-76COOH would significantly reduce the development of proteinuria in the early stage of BSA nephritis, but it failed to suppress proteinuria in the late stage. There was no significant difference in glomerular changes between treated animals and non-treated controls. These findings suggest that C5, and the terminal complement components may play a significant role in protein excretion in the early stage of immune complex glomerulonephritis. 相似文献
6.
Kono Y Horie M Takano M Otani H Xie LH Akao M Tsuji K Sasayama S 《Pflügers Archiv : European journal of physiology》2000,440(5):692-698
Functional ATP-sensitive K (KATP) channels have an octameric subunit structure with four pore-forming subunits (Kir6.x) and four sulfonylurea receptors (SURx). In the present study, the properties of the heteromeric KATP channel whose pore subunits are composed of Kir6.1 and Kir6.2 were examined using a heterologous expression system. In COS7 cells co-transfected with Kir6.1, Kir6.2 and SUR2A at a ratio of 1:1:2, KATP channels showed various unitary conductances between those of Kir6.1/SUR2A (33.6+/-4.2 pS) and Kir6.2/ SUR2A (67.1+/-1.6 pS). Kir6.1-6.2 tandem protein, constructed by fusing the C-terminus of Kir6.1 to the N-terminus of Kir6.2 with a ten glutamine linker sequence, also formed a channel with an intermediate conductance (58.9+/-1.5 pS). Kir6.2 and Kir6.1-6.2 showed similar sensitivity to ATP4-: half-maximal inhibition (IC50) was obtained at 14.1+/-12.8 microM and 17.6+/-9.6 microM, respectively. In the presence of Mg2+, Kir6. 1-6.2 was significantly less sensitive than Kir6.2 to MgATP (IC50=95.5+/-49.6 microM versus 18.9+/-5.0 microM). These results suggest that Kir6.1 and Kir6.2 are endowed with the potential to form a heteromeric KATP channel, which has a low sensitivity to MgATP. 相似文献
7.
Role of KCNQ1 in the cell swelling-induced enhancement of the slowly activating delayed rectifier K(+) current 总被引:2,自引:0,他引:2
Kubota T Horie M Takano M Yoshida H Otani H Sasayama S 《The Japanese journal of physiology》2002,52(1):31-39
Cell swelling enhances a slowly activating delayed rectifier K(+) current (I(Ks)) in cardiac cells. This investigation was undertaken to determine which of the two structural units reconstituting the I(Ks) channel, KCNQ1 (KvLQT1) and KCNE1 (minK/IsK), plays a key role in the cell swelling-induced I(Ks) enhancement and to dissect a possible involvement of tyrosine phosphorylation therein. KCNQ1 was transiently expressed alone or together with KCNE1 in a heterologous mammalian cell line. Two distinct whole-cell membrane currents were separately observed during the exposure of transfected cells to various degrees of hyposmotic solutions. A hyposmotic challenge (0.7 times control osmolarity) resulted in about a twofold increase not only in the heteromeric KCNQ1/KCNE1, but also in the homomeric KCNQ1 channel currents. There was no significant difference in the incremental ratio of current amplitude in response to hyposmotic stress between the two KCNQ1-related currents, and the cells expressing the heteromeric channels swelled less than those with the homomeric channels or without the exogenous ones. The cell swelling-induced I(Ks) enhancement was not affected by a protein tyrosine kinase (PTK) inhibitor, by genistein (50 microM), or by an inhibitor of phosphotyrosine phosphatase (PTP), orthovanadate (500 microM), or a nonhydrolyzable ATP analogue, AMP-PNP (5 mM). Taken together, it is very likely that KCNQ1 might primarily participate in the I(Ks) enhancement by osmotic cell swelling. The obligatory dependence of the I(Ks) augmentation on PTK activity remained to be demonstrated, at least, in this expression system. 相似文献
8.
Kakio T Matsumori A Ono K Ito H Matsushima K Sasayama S 《Laboratory investigation; a journal of technical methods and pathology》2000,80(7):1127-1136
Reperfusion injury is a troublesome and unresolved problem in acute myocardial infarction and is believed to be associated with inflammatory reactions in which various types of cells and cytokines participate, in particular, macrophages and monocyte chemoattractant protein-1 (MCP-1). We designed this study to clarify the role and relationship of macrophages and MCP-1 in ischemic and reperfused heart. The number and distribution of macrophages and MCP-1 messenger RNA (mRNA) in the ischemic and reperfused rat heart were examined with in situ hybridization and immunohistochemistry. Myocardial samples were obtained at several times. In situ hybridization was performed with digoxigenin-labeled antisense RNA probe for rat MCP-1 mRNA, and immunohistochemistry was performed with antimacrophage antibody. Double staining with in situ hybridization and immunohistochemistry was also performed. The number of MCP-1 mRNA-positive cells increased after reperfusion and peaked at 3 hours after reperfusion. Early infiltration of ischemic tissues by macrophages was also observed at the time of the absence of an increase of MCP-1 mRNA-positive cells, and this infiltration was not significantly accelerated by reperfusion, but by ischemia itself. The numbers of both MCP-1 mRNA-positive cells and macrophages increased in the ischemic marginal region over time. From the result of double staining, and based on the cellular morphology and the distribution, the majority of MCP-1 mRNA-positive cells appeared to be activated macrophages. This suggests that macrophages may not be attracted to cardiac tissue only by MCP-1 and that MCP-1 may have some roles other than attracting macrophages into ischemic heart. It also suggests that macrophages and MCP-1 may play an important role in reperfusion injury and that MCP-1 may be one of the key molecules of reperfusion injury. These observations may contribute to the development of a new therapeutic approach to the prevention of reperfusion injury. 相似文献
9.
Neurosurgical Review - Although transvenous embolization (TVE) via the superior ophthalmic vein (SOV) is adopted in treating cavernous sinus dural arteriovenous fistula (CS DAVF), its effect on the... 相似文献
10.
Calcaneus Bone Mineral Density is Lower Among Men and Women with Lower Physical Performance 总被引:5,自引:0,他引:5
Aoyagi K Ross PD Hayashi T Okano K Moji K Sasayama H Yahata Y Takemoto T 《Calcified tissue international》2000,67(2):106-110
Fracture risk is influenced by both bone strength and by falls. Measures of physical function and performance are predictors
of falls. However, the interrelationships among bone mineral density (BMD), regular physical activity, and measures of physical
performance are not well known. We studied 447 community-dwelling Japanese people aged 40 years and over (96 men and 351 women)
to examine the association of calcaneus BMD with measures of physical performance (grip strength, walking speed, chair stand,
and functional reach) and regular physical activity. Calcaneus BMD decreased with age by approximately 25% in men and 42%
in women. Measures of physical performance decreased with age by approximately 30% in both genders, however, performance on
the chair stand test declined by approximately 60%. There were only minimal differences in performance measures and calcaneus
BMD between people with and those without regular physical activity in both genders, and most differences were not significant.
However, there were significant BMD increases of 3–6% per standard deviation (SD) increase in all performance measures for
women and a 7% increase in BMD per SD increase in grip strength for men, after adjusting for age. These associations remained
after additional adjustment for body mass index and regular physical activity. These findings suggest that bone density and
physical function decline markedly in both men and women with age, and that low BMD and poor function tend to occur together,
which would increase fracture risk more than either risk factor alone.
Received: 9 August 1999 / Accepted: 4 February 2000 相似文献