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Somites are formed by periodic segmentation of the presomitic mesoderm (PSM). This periodic event is controlled by the segmentation clock, where Notch signaling plays an essential role. The basic helix-loop-helix factor Hes7, a Notch effector, is cyclically expressed by negative feedback and regulates cyclic expression of Lunatic fringe (Lfng), a Notch modulator. Lfng then seems to periodically inhibit Notch, leading to oscillation in Notch activity. It is thought that these coupled negative feedback loops by Hes7 and Lfng are important for sustained and synchronized oscillations in the PSM. Of interest, another Notch effector, Hes1, is cyclically expressed by many cell types such as neuroblasts, suggesting that this clock is widely distributed and regulates many biological events. This review summarizes the recent finding about roles and mechanism of Notch signaling in the segmentation clock and discusses the significance of Hes1 oscillation in non-PSM cells. 相似文献
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Yoshito Tomimaru Ken Kodama Jiro Okami Kazuyuki Oda Koji Takami Masahiko Higashiyama 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(5):193-198
Objective Postoperative pericardial effusion commonly occurs after open heart surgery. However, after general thoracotomy such as pulmonary
resection, there have been few reports of pericardial effusion. The purpose of this study is to investigate patients with
pericardial effusion following pulmonary resection.Methods: Among 2,385 patients with pulmonary resection for lung neoplasm in our institute, eight patients, whose pericardium had
never been opened during the operation, developed pericardial effusion. The clinical characteristics of the eight patients
were analyzed.Results: Pericardial effusion after pulmonary resection was divided into two subtypes: pericardial effusion in three patients with
left thoracotomy occurring within 30 days postoperatively, and pericardial effusion in the remaining five patients with right
thoracotomy occurring more than 30 days postoperatively. Pericardiotomy or pericardiocentesis was performed in three symptomatic
patients, and the remaining five asymptomatic patients were treated with diuretics. Pericardial effusion disappeared in three
of the five patients about 1–3 months after the conservative treatment, while, in the remaining patients, because pericardial
effusion had increased gradually, pericardiocentesis was performed.Conclusion: From our experience, the treatment strategy of drainage for early pericardial effusion and diuretics for late pericardial
effusion seems to be appropriate. (Jpn J Thorac Cardiovasc Surg 2006; 54:193-198) 相似文献
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Yoshito Sadahira Masaharu Mori Michitaka Ozaki Michiyasu Awai 《Pathology international》1987,37(11):1719-1729
The so-called Potter's lesion, previously described as preneoplastic in the lymph nodes of C58 mice, develops frequently in autoimmune NZB mice. These lesions were characterized in the present study by bands or sheets of palestaining histiocytic cells in the cortex and medulla of the lymph node, and multiple small nodules of the same cells were found in the red pulp of the spleen and the liver. Electron microscopically, the cells had pleomorphic cytoplasm with long processes, electron-dense bodies, abundant mitochondria, and a characteristic labyrinth structure with many C-type viruses. Mac-1 antigen, IgG-Fc receptor, ferritin, and ACPase activity were identified on these cells. Intraperitoneally-injected iron colloids were found in the lesions of the spleen and liver but not in those of the lymph nodes. The lymph node lesions appeared when the mice were about 3 months of age and enlarged until the mice were around 10 months old, after which they gradually receded and were replaced by small vessels and fibroblastic cells. These data indicate that the lesions represent reactive hyperplasia of the macrophage system and may have no direct association with the development of malignant lymphoma in NZB mice. 相似文献
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Takashi Ishimori Satoru Nakano Masahiro Kagawa Koiku Yokoe Tarou Togami Hirofumi Asakura Toshiaki Kusuhara Motoomi Ohkawa Syeigo Nagao Yuichi Yamashita Satoshi Sugiura 《Magnetic resonance in medical sciences》2003,2(3):145-149
Three-dimensional fast asymmetric spin echo (3D FASE) cisternography provides high spatial resolution and excellent contrast as a water image acquisition technique. It is also useful for the evaluation of various anatomical regions. This study investigated the usefulness and limitations of virtual endoscopic images obtained by 3D FASE MR cisternography in the preoperative evaluation of patients with neurovascular compression. The study included 12 patients with neurovascular compression: 10 with hemifacial spasm and two with trigeminal neuralgia. The diagnosis was surgically confirmed in all patients. The virtual endoscopic images obtained were judged to be of acceptable quality for interpretation in all cases. The areas of compression identified in preoperative diagnosis with virtual endoscopic images showed good agreement with those observed from surgery, except in one case in which the common trunk of the anterior inferior cerebellar artery and posterior inferior cerebellar artery (AICA-PICA) bifurcated near the root exit zone of the facial nerve. The veins are displayed in some cases but not in others. The main advantage of generating virtual endoscopic images is that such images can be used for surgical simulation, allowing the neurosurgeon to perform surgical procedures with greater confidence. 相似文献
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Reoperation after aortic valvuloplasty for aortic regurgitation associated with ventricular septal defect 总被引:1,自引:0,他引:1
Y Ohkita S Miki K Kusuhara Y Ueda T Tahata M Komeda T Tamura 《The Annals of thoracic surgery》1986,41(5):489-491
Five patients underwent reoperations because residual or recurrent aortic regurgitation occurred after aortic valvuloplasty for aortic regurgitation associated with ventricular septal defect. The mean age at reoperation was 22 years old, and the mean time interval between initial and second operation was 6 years, 10 months. The pathological findings of the aortic valves showed tears and perforation of repaired leaflets in four patients and a giant pseudoaneurysm of the Valsalva sinus in one. Aortic valvuloplasties were performed again in three patients, and aortic valves were replaced with prosthetic valves in two. Slight to moderate regurgitant murmurs are still audible in patients who underwent these valvuloplasties. Ventricular septal defects should be closed before aortic regurgitation develops. If it has developed, however, valvuloplasty should be considered as a first choice in young patients. For adult patients, aortic valve replacement is recommended. 相似文献