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排序方式: 共有419条查询结果,搜索用时 15 毫秒
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CA von Arnim R Spoelgen ID Peltan M Deng S Courchesne M Koker T Matsui H Kowa SF Lichtenthaler MC Irizarry BT Hyman 《The Journal of neuroscience》2006,26(39):9913-9922
The beta-amyloid (Abeta) precursor protein (APP) is cleaved sequentially by beta-site of APP-cleaving enzyme (BACE) and gamma-secretase to release the Abeta peptides that accumulate in plaques in Alzheimer's disease (AD). GGA1, a member of the Golgi-localized gamma-ear-containing ARF-binding (GGA) protein family, interacts with BACE and influences its subcellular distribution. We now report that overexpression of GGA1 in cells increased the APP C-terminal fragment resulting from beta-cleavage but surprisingly reduced Abeta. GGA1 confined APP to the Golgi, in which fluorescence resonance energy transfer analyses suggest that the proteins come into close proximity. GGA1 blunted only APP but not notch intracellular domain release. These results suggest that GGA1 prevented APP beta-cleavage products from becoming substrates for gamma-secretase. Direct binding of GGA1 to BACE was not required for these effects, but the integrity of the GAT (GGA1 and TOM) domain of GGA1 was. GGA1 may act as a specific spatial switch influencing APP trafficking and processing, so that APP-GGA1 interactions may have pathophysiological relevance in AD. 相似文献
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应用放射配体结合法证实大鼠胸腺内存在降黑素特异结合部位,该结合位点可以满足特异结合部位的基本条件:1.低结合容量;2.高亲和力;3.可饱和性;4.可逆性;5.对降黑素高度特异性。此外,该特异结合位点具昼夜节律;亚细胞分布的研究表明以细胞核含量最高,线粒体次之,并具有年龄依赖性降低,以出生时最高。 相似文献
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Kung FT; Chen WJ; Chou HH; Ko SF; Chang SY 《Human reproduction (Oxford, England)》1997,12(8):1649-1653
We report a rare case of early-stage endometrial adenocarcinoma in a 22
year old nullipara with polycystic ovaries undergoing conservative
treatment. Pretreatment evaluation including tumour grade, depth of
myometrial invasion, tumour size, hormone receptor status and flow
cytometric analysis indicated a favourable prognosis. The patient underwent
repeat endometrial curettage and a 6 month period of therapy with megestrol
acetate and tamoxifen. A combination contraceptive pill was then prescribed
to ensure withdrawal of the menstrual cycle thereafter. Now, 1 year after
the last curettage, there is no evidence of disease. During the treatment
period, hysteroscopy allowed for a more precise approach in panoramically
examining the tumour nest in the endometrial cavity, and the subsequent
endometrial response to hormone therapy. Laparoscopy using bulldog clamps
applied to the isthmic portion of the Fallopian tubes prevented i.p. spread
of endometrial tissue from retrograde regurgitation during hysteroscopy.
Laparoscopic ovarian electrocautery resulted in the reduction of abnormal
hypervascularization on the surface of polycystic ovaries postoperatively
but caused a peri-ovarian adhesion complication. It is interesting that
this case posed a unique opportunity to demonstrate the tumour regression
under the assistance of laparoscopy and hysteroscopy.
相似文献
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Castro DJ Saxton RE Soudant J Calcaterra T Lufkin R Nyerges A Aldinger J Paiva M Anzai Y Chung PS 《Journal of clinical laser medicine & surgery》1994,12(2):65-73
Imaging-guided palliative therapy of recurrent and/or inaccessible head and neck tumors may soon become clinically practical since sensitive and noninvasive monitoring techniques of energy deposition in tissues are now available. Interstitial tumor therapy (ITT) is a technique whereby a source of energy (laser, radiofrequency, ultrasonic, cryoenergy, etc.) is directly applied into tumors at various depths. Recent studies have demonstrated the efficiency of ultrasound (UTZ) and magnetic resonance imaging (MRI) for real and/or "near" real time tumor and vessel identification as well as monitoring and quantifying energy-induced tissue damage. We now report our initial clinical experience with patients in which UTZ and/or MRI-guided ITT techniques were successfully applied for the treatment of recurrent, nonresectable, local, and/or metastatic head and neck carcinomas. Patients were treated on an outpatient basis either in the operating room or in an upgraded specially equipped SIGNA 1.5T MR suite. Most patients tolerated these procedures well and were successfully palliated for periods ranging from 3 months to 5 years posttreatment. The upgrades introduced in a standard MRI suite, the clinical experience, and future perspectives will be reviewed. 相似文献
7.
3D-based production of hip joints: the Aldinger system 总被引:4,自引:0,他引:4
Total hip replacement is regarded as one of the most successful surgical procedures. However, aseptic loosening of the foreign material still remains a great problem with endoprostheses. Bone cement, a material for filling and fitting, allows a solution to the problem in old people, but for younger people surgeons have looked for alternatives without cement. In fixation hip stems without form-filling cement, the greatest difficulty with standardized stems was the lack of adequate fit into the individual bone cavity. The new approach, the Aldinger custom-made hip stem, is based on a series of computer tomographical X-rays. This free-styled prosthesis stem is derived directly from the 3D-reconstruction of the inner contour of the femur without any parametrization of the cross-sections. A simulation of the implantation procedure is performed to ensure the implantability of the prosthesis and to give the surgeon some useful hints for the individual operation. In addition to the excellent form-fit to the individual bone, this prosthesis has further advantages such as the special disk-like surface structure, allowing good stress transfer to the bone, and the possibility of positioning the artificial head freely in three dimensions according to the requirements of therapy. Seven years of experience with this new system demonstrate that "computer-fit" can be a successful alternative to "cement-fit," especially in younger patients with a life expectancy of more than 10-15 years. 相似文献
8.
Pierre Robin sequence (PRS) describes a small mandible with retrognathia, an elevated and posteriorly positioned tongue, and an associated U-shaped cleft palate. The retracted tongue may obstruct the airway leading to respiratory failure, with failure to thrive and adverse neurodevelopmental outcomes if not addressed. If the airway obstruction cannot be overcome with conservative measures, there are non-surgical and surgical options. A nasopharyngeal prong (NPP) is a non-surgical, temporary treatment that avoids the complications inherent in an operation, especially given the natural history of mandibular growth and improved airway obstruction in PRS. Although the use of a prong requires training, support, and follow up, it effectively bypasses the obstruction in the majority of children with PRS, and allows the child to outgrow the airway obstruction until the prong is no longer required. On average, the prong can be removed between 6 and 12 months of age. 相似文献
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Kameoka J; Sato T; Torimoto Y; Sugita K; Soiffer RJ; Schlossman SF; Ritz J; Morimoto C 《Blood》1995,85(4):1132-1137
Patients who have undergone allogeneic bone marrow transplantation (allo-BMT) are susceptible to a variety of opportunistic infectious complications in the months to years after engraftment. Impaired in vitro T-cell functions have been documented in these patients, and these T-cell dysfunctions contribute to the prolonged immune deficiency after allo-BMT. In the present study, we examined the expression of CD26 as well as the reconstitution of CD26-mediated T-cell costimulation via the CD3 and CD2 pathways at various times in patients aged greater than 18 years after CD6-positive, T-cell depleted allo- BMT. We found that the percentage of CD26- and CD3-positive cells, as well as the levels of expression of both antigens, was lower than in normal controls during the first 4 months after CD6-depleted allo-BMT. Subsequently, the amount of lymphocytes expressing CD3 and CD26 and the quantitative surface expression of CD3 and CD26 were not significantly different in patients and normal controls. Functional studies showed that CD26-mediated T-cell proliferation via the CD3 pathway was considerably improved and almost reached normal levels by 1 year, whereas recovery of CD26-mediated T-cell proliferation via the CD2 pathway was delayed for at least 2 years after CD6-depleted allo-BMT. As CD26 involvement in the regulation of human thymocyte activation is restricted preferentially to the CD3 pathway--unlike its involvement with both CD3 and CD2 pathways of peripheral T cells--our results suggest that the different effects of CD26-mediated costimulation via the CD3 and CD2 pathways after CD6-depleted allo-BMT may be a reflection of peripheral T-cell immaturity in those individuals, similar to that seen in mature medullary thymocytes or cord T lymphocytes. 相似文献