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排序方式: 共有1023条查询结果,搜索用时 15 毫秒
1.
Keigo Kohara Tomio Ono Keiko Tominaga-Yoshino Tomokazu Shimonaga Seiichi Kawashima Akihiko Ogura 《Brain research》1998,809(2):285
Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca2+ concentration ([Ca2+]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca2+]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca2+]i between the two culture conditions. Influx of Ca2+ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca2+ due to the activity of Ca2+/Na+ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca2+ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca2+ turnover. 相似文献
2.
Cardiovascular depression occuring when diazepam is combined with fentanyl has been investigated using the benzodiazepine antagonist RO15-1788 in the dog.After the initial administration of fentanyl (40mcg/kg), the mean arterial pressure (MAP) decreased to 89% of its control value. Following the administration of diazepam (1.2mg/kg), the MAP and the total peripheral resistance (TPR) decreased significantly, to 75% and 83% of their control values respectively. After the administration of RO15-1788 (0.4mg/kg), the MAP increased significantly to 90% and the TPR to 102% of their control values and, lastly, the administration of naloxone (40mcg/kg) increased the MAP to 108% of its control value. No relationship was found between the changes in the catecholamines and the changes in the MAP after the administration of fentanyl, diazepam, and RO15-1788.The mechanism of circulatory depression when diazepam was used with fentanyl is interpreted as being a peripheral vasodilatory effect of diazepam acting by way of the benzodiazepine receptors since RO15-1788 was found to antagonize this effect.(Sone T, Kato T, Tsukahara I et al.: The effect of RO15-1788 on cardiovascular depression caused by fentanyl and diazepam. J Anesth 2: 69–76, 1988) 相似文献
3.
Anjali Ramaswamy Nina N. Brodsky Tomokazu S. Sumida Michela Comi Hiromitsu Asashima Kenneth B. Hoehn Ningshan Li Yunqing Liu Aagam Shah Neal G. Ravindra Jason Bishai Alamzeb Khan William Lau Brian Sellers Neha Bansal Pamela Guerrerio Avraham Unterman Victoria Habet Carrie L. Lucas 《Immunity》2021,54(5):1083-1095.e7
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4.
Production and release of infectious hepatitis C virus from human liver cell cultures in the three-dimensional radial-flow bioreactor 总被引:5,自引:0,他引:5
Aizaki H Nagamori S Matsuda M Kawakami H Hashimoto O Ishiko H Kawada M Matsuura T Hasumura S Matsuura Y Suzuki T Miyamura T 《Virology》2003,314(1):16-25
Lack of efficient culture systems for hepatitis C virus (HCV) has been a major obstacle in HCV research. Human liver cells grown in a three-dimensional radial-flow bioreactor were successfully infected following inoculation with plasma from an HCV carrier. Subsequent detection of increased HCV RNA suggested viral replication. Furthermore, transfection of HCV RNA transcribed from full-length cDNA also resulted in the production and release of HCV virions into supernatant. Infectivity was shown by successful secondary passage to a new culture. Introduction of mutations in RNA helicase and polymerase regions of HCV cDNA abolished virus replication, indicating that reverse genetics of this system is possible. The ability to replicate and detect the extracellular release of HCV might provide clues with regard to the persistent nature of HCV infection. It will also accelerate research into the pathogenicity of HCV, as well as the development of prophylactic agents and new therapy. 相似文献
5.
The topological changes of the human autonomic cardiac nervous system in two cadavers with a retroesophageal right subclavian
artery (Rersa) were compared with the normal autonomic cardiac nervous system. The following new results were obtained in
addition to the conventional deficient finding of the right recurrent laryngeal nerve. (1) Right superior cardiac nerves arising
from the superior cervical ganglion were consistently observed in both cadavers, in addition to the right thoracic cardiac
nerves along the Rersa. (2) A segmental accompanying tendency of the right cardiac nerves was recognized: the cardiac nerves
arising from the sympathetic trunk cranial to the middle cervical ganglia ran along with the right common carotid artery,
whereas the cardiac nerves arising from the sympathetic trunk caudal to the vertebral ganglion ran along the Rersa. (3) The
right thoracic cardiac nerves, which have never been observed to accompany the normal right subclavian artery, ran along the
proximal part of the Rersa. According to previous reports of individuals with the Rersa, a thick right thoracic cardiac nerve
is commonly observed instead of a right superior cardiac nerve. However, all the cardiac nerves were recognized in both the
individuals described in the present report. Therefore, we strongly disagree with the previous idea that the origin of the
right cardiac nerves from the sympathetic trunk and ganglia is shifted caudally in individuals with the Rersa. The topological
changes of the autonomic cardiac nervous system in two cases of Rersa also reflected spatial changes of great arteries. 相似文献
6.
Murata K Inami M Hasegawa A Kubo S Kimura M Yamashita M Hosokawa H Nagao T Suzuki K Hashimoto K Shinkai H Koseki H Taniguchi M Ziegler SF Nakayama T 《International immunology》2003,15(8):987-992
CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients. 相似文献
7.
Jojiro Nakada Hiroyuki Ito Nozomu Furuta Yukihiko Oishi Yutaka Yamaguchi Tomokazu Matsuura Yoshiaki Hataba Seishi Nagamori 《Medical Electron Microscopy》2002,35(1):53-59
We conducted ultrastructural analysis of human pheochromocytoma (PC) cells maintained in primary culture for about 10 months. The cells were first isolated by the enzymatic treatment of a surgically resected tissue specimen obtained from a 37-year-old man with PC, a condition which is characterized by elevated blood levels of adrenaline and noradrenaline. It was found that noradrenaline production in the medium continued until the 90th day of culture (1330 pg/ml). The production level decreased to 20 pg/ml on the 180th day, and to 18 pg/ml on the 300th day. Examination under a transmission electron microscope (TEM) at 4 weeks of culture revealed electron-dense granules (about 200 nm in size and, presumably, rich in catecholamines), which were also observed in the tumor cells from the original PC tissue. Neurite-like processes grew at around 1 week of culture, and were still maintained at 6 months of culture. But, after 6 months of culture, the neurite-like processes contained a rosary-like elevated structure, which was suggestive of cell degeneration, as determined by a plasma polymerization replica method and observed with a scanning electron microscope. When cells were examined under the TEM, fewer electron-dense granules were observed in the cell bodies, with more numerous lipofuscin-like granules and filaments. Thus, electron-dense granules, which, presumably, contain catecholamines, were seen in a long-term culture of human PC cells. These granules decreased in number in parallel with the decrease in catecholamine levels in the culture. 相似文献
8.
The anatomical relationship between the kidney position and its arterial supply was investigated in 21 mammals, 1 bird, and 3 reptiles (n = 1 for each species) and in 43 human cadavers. The following observations were made. (1) Although the right kidney was located caudal to the left kidney in 29 out of 43 human cadavers (67.4%), the origin of the right renal artery from the aorta was located cranial to the origin of the left renal artery in 36 human cadavers (83.7%). Therefore, the relative positions of the kidneys do not correspond with the relative origins of the renal arteries in humans. (2) Among the mammals that were examined, the position of the kidney and the branching level of the renal artery on the right side were usually cranial to those on the left side. (3) In the bird and most reptiles that were examined, kidneys were typically located in the pelvic region and were supplied by segmental arterial branches. These results suggest that the right kidney and its arterial supply are generally located cranial to the left kidney in phylogeny of mammals. While the presence of a human accessory renal artery in 9 out of 86 sides (10.5%) and a cranial origin of the left renal artery relative to the right renal artery in 7 out of 43 cadavers (16.3%), shows some variation in the arterial supply to the kidneys, the origin of the renal arteries can generally be used as phylogenetic landmarks indicating the relative positions of the kidneys. Hence, from an ontological perspective, the human right kidney may be initially situated cranial to the left kidney during the early stages of development. Thereafter, the human right kidney may shift downwards secondary. 相似文献
9.
Dihydropyrimidine dehydrogenase activity in 150 healthy Japanese volunteers and identification of novel mutations. 总被引:4,自引:0,他引:4
10.
Tomokazu Kishiki Hiroaki Ohnishi Tadahiko Masaki Kouki Ohtsuka Yasuo Ohkura Jyunji Furuse Takashi Watanabe Masanori Sugiyama 《Cancer chemotherapy and pharmacology》2014,73(4):749-757