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151.
Cerebralvasospasm(CVS)remainsoneofthemajorcausesofseriousoutcomeinpatientswithsubarachnoidhemorrhage(SAH);however,themechanismofwhichisstillnotwellunderstood.Sofaralargenumberofputativespasmogenshavebeenproposedandoneofwhichisendothelins(ETs).ETs,akindofverypotentendogenousvasoconstrictorsubstancesknown[1],hasthreeiso-forms:ET-1,2and3,andET-1isthemostpo-tentvasoconstrictorofthem.lnrecentstudies,ET-lhasbeenproposedasamediatorofCVSfol-lowingSAH[2-4j.TheavailabilityofETantagonistprovided…  相似文献   
152.
The crystallization behavior of coextruded microlayered sheets comprised of 657 alternating layers of polycarbonate (PC) and a miscible copolyester of mainly 1,4-cyclohexanedimethanol and terephthalic acid (KODAR) was investigated as a function of annealing time when the KODAR was crystallized isothermally from the glass at 195°C. Comparisons were made with crystallization of KODAR alone, and with crystallization of KODAR from melt blends with PC. The kinetics of crystallization and the morphology of the crystallized KODAR were characterized with differential scanning calorimetry, and by examination of thin sections microtomed from annealed specimens in the polarized light microscope and the transmission electron microscope. The growth rate of small, birefringent KODAR spherulites was non-linear, and was strongly affected by diffusion of PC into the KODAR layers. Diffusion of amorphous PC into the KODAR layers retarded nucleation and spherulite growth and decreased spherulite density. The effect became more pronounced as the KODAR layer thickness was reduced. Spherulities nucleated randomly throughout the KODAR layers in the PC/KODAR 20/80 (w/w) microlayer and grew rapidly to form a continuous layer of impinged spherulites. In contrast, spherulites in the PC/KODAR 40/60 and 60/40 microlayers nucleated and grew along the center of the KODAR layers where the KODAR concentration was highest.  相似文献   
153.
We investigated the importance of prostaglandin E2 (PGE2) release in interleukin-1 (IL-1)-induced inhibition of aggrecan synthesis by chondrocytes. Keratan sulfate (KS) production was measured in parallel with PGE2 release in chondrocytes. IL-1 inhibited KS production and stimulated PGE2 release. In the presence of PGE2, there was a dosedependent decrease in baseline KS production. Indomethacin and dexamethasone partially blocked the IL-1-induced PGE2 release while KS production recovered. Our results suggest that IL-1 inhibits KS production, in part, by stimulating the release of PGE2.  相似文献   
154.
卡介苗激活杀伤细胞抗膀胱肿瘤作用研究   总被引:1,自引:0,他引:1  
为了进一步探讨BCG抗膀胱肿瘤的作用机理,采取15例膀胱肿瘤患者外周血单个核细胞(PBMC),置于含BCG或IL2的培养基中培养,计算扩增倍数,检测培养细胞抗自体及异体膀胱癌细胞活性。结果:卡介苗激活杀伤细胞(BAK)与淋巴因子激活杀伤细胞(LAK)分别于培养第7和第3天达增殖高峰,对自体瘤杀伤率分别为36.2%和31.4%,差异有显著性(P<0.05);对异体瘤杀伤率分别为25.2%和28.3%,差异无显著性。结果表明:BAK细胞抗自体瘤活性高于LAK细胞,死BCG对PBMC无激活作用,BAK细胞抗肿瘤效应可能是BCG抗膀胱肿瘤重要作用机理之一。  相似文献   
155.
戴军  陈玉林 《广东医学》1998,19(3):170-171
目的:通过阻断烫伤早期大鼠中枢和下丘脑室旁核γ-氨基丁酸的作用,观察大鼠心血管指标和存活时间的改变。方法:制备大鼠30%总体表面积Ⅲ度烫伤模型;借助脑立体定向仪行中枢内注射;运用四导生理仪记录血压和心肌力学指标。结果:烫伤早期大鼠中枢和下丘脑室旁核γ-氨基丁酸作用的阻断可明显回升其血压、左心室收缩压、左心室内压最大变化速率和延长存活时间。结论:提示中枢γ-氨基丁酸对大鼠烫伤早期心血管功能有影响,部  相似文献   
156.
论述了电脑控制连续式料位仪的原理及性能,研制了一种先进可靠的物料料位测量工具。  相似文献   
157.
Twenty-one patients, under 6 years of age, with root avulsion of the brachial plexus were treated from 1975 to 1987. Among them, 9 had root avulsion of the upper trunk, 2 root avulsion of the lower trunk with middle trunk broken, and 10 root avulsion of the whole brachial plexus. Follow-up of 16 patients showed excellent results in 2 patients, good in 11, fair in 1 and poor in 2. It is suggested that good results can be obtained if multi-paired nerve transfer is adopted in treatment. We conclude that owing to anatomical and physiological characteristics of the respiratory system in children, it is harmful to perform phrenic nerve transfer concomitantly with intercostal nerve transfer. Advisably, two-stage operation is required, otherwise dyspnea and pneumonia are liable to occur. In addition, the time of the operation could be extended to 4-5 years after injury in children, but best results are obtained if the operation is performed within 1 year.
  相似文献   
158.
MK-679 (R(?)-3-((3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl)(3-(dimethylamino)-3-oxopropyl)thio)methyl)thio(propanoic acid) is a potent and specific LTD4-receptor antagonist. The disposition of MK-679 was investigated in a three-way crossover study in 12 healthy males receiving single intravenous doses of 75, 250, and 500 mg of MK-679. A greater than proportional increase in the area under the plasma concentration—time curve of MK-679 was observed with increase in dose. The plasma concentration data for each subject fitted well to the differential equations for a two-compartment model with linear tissue distribution and Michaelis-Menten elimination from the central compartment, indicating that the elimination of MK-679 in humans is saturable. In a previous study, the disposition of MK-679 in humans was also dose-dependent when given together with its S(+)-isomer, L-668,018. Thus, the disposition of MK-679 in humans is dose-dependent regardless of the presence of its stereoisomer. Also, the bioavailability of MK-679 was determined in six healthy males receiving simultaneously an oral dose of 250 mg of MK-679 and intravenous infusion of 1 mg 14C-MK-679. Results of this study indicate that the oral bioavailability of MK-679 is nearly quantitative.  相似文献   
159.
孙琼  俞锡林 《营养学报》1992,14(3):266-269
本文对14岁以下健康小儿171名,成人30名及初生儿脐带血30份进行了血清叶酸和维生素B_(12)含量测定,171名小儿于采血前均经补足叶酸和维生素B_(12)。结果:血清叶酸(nmol/L)的正常值低限,<4岁者为6.1,4~14岁为8.4,成人为5.0;血清维生素B_(12)(pmol/L)的正常值低限,<1岁为459,1岁~成人为107。  相似文献   
160.
W C Cheng  A D Wang 《Neurosurgery》1990,27(5):802-805
Carotid-cavernous sinus fistulas are not rare, but they have never been reported in association with persistent primitive trigeminal artery. We recently encountered such a case. The Jaeger-Hamby procedure was employed, with mandatory occlusion of the primitive trigeminal artery.  相似文献   
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