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31.
光化学诱导的血栓形成性脑缺血及其代谢改变 总被引:4,自引:2,他引:4
本文用光化学法激发大鼠局部脑血栓形成,以组织病理学、局部脑血流量、皮层水含量、三磷酸腺苷、二磷酸腺苷,一磷酸腺苷、能量负荷、肌酸及乳酸为指标,探讨局部脑血栓形成后5天rCBF明显增高的可能机理。结果表明,血栓形成后局部脑组织ATP水平进行性减少(P<0.01)、ADP/ATP及AMP/ATP比值明显升高(P均<0.01),LA及脑水含量显著增加(P<0.01)。这些因素既是能量衰竭、无氧酵解的结果 相似文献
32.
左心室局部心肌梗塞时的组分式模型及计算机仿真 总被引:1,自引:0,他引:1
为研究左心室局部心肌梗塞时心肌各部分的能量供需状况及心脏辅助装置对改善心肌能量供给的影响,我们建立了一个由左心室正常区域心肌和梗塞区域心肌两部分组成的组分式模型,我们的模型以Sunagawa的模型为基础,并在此基础上加以扩展,与Sunagawa的模型相比,我们的模型允许梗塞区域心肌的收缩性在一定范围内变化,从而可以模拟各种不同范围和不同程度的梗塞情况。用建立好的左心室组分式模型取代我们原有的狗的心 相似文献
33.
Summary The patterns of regional changes of sympathetic efferent activity evoked by thermal stimulation of the spinal cord and by arterial and primary tissue hypoxia were investigated in decerebrated, anesthetized and immobilized rabbits. Decerebration was performed either at the mid- or infracollicular level. The responses of the decerebrated rabbits evoked by spinal thermal stimulation were the same as those of intact rabbits, i.e., splanchnic and cardiac sympathetic activity increased and cutaneous sympathetic activity decreased during warming, while the reverse response was elicited by cooling. It is concluded that the typical thermoregulatory response pattern of the sympathetic nervous system can be produced also after the loss of hypothalamic integration, i.e., by integrative mechanisms in the lower brain stem and the spinal cord. In contrast, the responses of decerebrated rabbits to arterial and primary tissue hypoxia differed from those of intact rabbits in that they consisted in an overall activation in all investigated sympathetic branches. It is confirmed by this result that suprabulbar integration is essential for the generation of the inhibitory components in the differential sympathetic responses to hypoxia, which typically consist in cutaneous and cardiac sympathetic inhibition with splanchnic activation during arterial hypoxia and in cutaneous sympathetic inhibition with cardiac and splanchnic sympathetic activation during primary tissue hypoxia. 相似文献
34.
Our knowledge about aging modulation of the central motor system remains sparse and contradictory. In the current study, we used functional MRI (fMRI) to study the aging influence on regional homogeneity of the motor-related brain areas in the resting state. We found that regional homogeneity in extensive motor regions, like the cingulate motor area, cerebellum, primary motor cortex, premotor area, supplementary motor area, thalamus, globus pallidus and putamen was significantly decreased in aged subjects. Our study indicates that normal aging process may disrupt the function of motor areas in the resting state, which may contribute to the declined motor ability in aged population. 相似文献
35.
36.
Dr. Joel M. Price 《Annals of biomedical engineering》1984,12(5):481-496
This study examines the effect of length on the dose-response (D-R) relationship and the effect of agonist concentration on
the length-tension (L-T) relationship in vascular smooth muscle. The experiments used 2-mm rings from isolated segments of
the dog anterior tibial artery. In D-R experiments the length (internal ring circumference) for maximum active force (Lmax) was determined first. D-R relationships were obtained from cumulative responses to increasing concentrations of norepinephrine
(NE) or potassium (K+). L-T relationships were obtained from individual responses to a specific concentration of agonist as the ring was stretched
in increments of L0 (the initial length for resting force). Dimensions of the arterial rings were measured with a video caliper. For NE and K+ stimulations at lengths equal to and less than Lmax: (a) The concentration for half maximal response (ED50) was lowest (most sensitive) at Lmax and increased significantly as length decreased from Lmax; (b) When the direction of length change was reversed, the direction of change in ED50 was reversed; and (c) The ED50 of repeated dose-response experiments at Lmax was not significantly different. For NE: (a) the ED50 decreased significantly when length was increased from Lmax; and (b) the ED50 increased significantly when length was decreased to Lmax. The results of L-T experiments show Lmax is significantly longer for a low concentration of NE (10−6 M) than for a high concentration (10−5 M). With force normalized to the maximum force, the L-T curve is significantly lower, and the initial length for an active
response was 80% longer for 10−6 M than for 10−5 M NE. It may be concluded that vascular smooth muscle has a length-dependent dose-response relationship and a concentration-dependent
length-tension relationship. 相似文献
37.
Reichart B. Schad N. Nickel O. Kemkes B. M. Kreuzer E. Harrington O. B. 《Journal of molecular medicine (Berlin, Germany)》1982,60(4):181-191
Summary Twenty consecutive patients (mean age 51.6 years) with persistent severe angina pectoris underwent aorto-coronary bypass surgery receiving an overall of 60 anastomosis. On an average, 9.4±1.5 months p.o. first pass radionuclide ventriculograms (18 to 24 mCi 99 m Technetium-Pertechnetate i.v.) were performed at rest and after excerise. Besides measurement of global ejection fraction (GEF), regional ejection fraction (REF) was assessed employing for the first time a new technique: each RAO-view of p.o. radionuclide left ventriculogram was subdivided into three regions according to supply of the three main coronary arteries and their branches as visualized on pre-operative coronary angiogram.GEF improved after maximum exercise in 13 cases by 8.1% points (from 50.4 to 58.5%), remained unchanged three times and decreased four times by 7.1 points (from 51.6 to 44.5%; all changesp<0.05).In completely revascularized regions (n=35) REF improved 24 times by 9.7 points (from 51.1 to 60.8%), did not differ from rest REF six times and decreased in three case by 7.3 points (from 48.6 to 41.3%; all changesp<0.05). Completely revascularized regions responded to exercise like normally perfused areas (increase 7.8 points (from 50.6 to 58.4%;n=7;p<0.05).REF deteriorated in incompletely revascularized regions (n=9) six times by 12.8 points (from 58.0 to 45.2%), remained unchanged twice and improved once by 4.5 points. Total group's REF decreased by 7.3 points (from 56.8 to 49.5%;p<0.05). Exercise REF of incompletely revascularized regions was highly significant inferior to that of completely revascularized regions (49.5 to 58.4%;p<0.01).GEF is a weighted balance of the three regional ejection fractions. The most important parameter is REF of LAD territory. 相似文献
38.
银杏叶制剂和丹参对急性肾衰兔肾皮质局部血流量的影响 总被引:8,自引:0,他引:8
目的探讨急性肾功能衰竭(acute renal failure,ARF)兔肾皮质局部血流量(regional renalblood flow,rRBF)与血液流变学的关系,以及银杏叶制剂(Ginkgo Bilobal Extraction,GbE)、丹参对其的影响.方法用50%的甘油10 ml/kg行兔后肢肌肉加压注射,建立ARF动物模型,观察血液流变学、rRBF的变化,并给予GbE、丹参注射液对比观察.结果 ARF组血液流变学指标明显异常,rRBF明显下降.ηb、ηb、EAI、HCT等与rRBF呈明显负相关(P均<0.05).GbE组、丹参组动物血液流变学、rRBF等指标明显改善.结论 ARF时血液流变特性恶化和肾局部微循环障碍可能是造成rRBF下降的直接原因之一.GbE、丹参对甘油所致ARF家兔的血液流变特性及肾组织缺血性损害有明显的保护作用. 相似文献
39.
宋佳 ' target='_blank'> 范成鑫 ' target='_blank'> 艾旭峰 ' target='_blank'> 刘馨璐.. 王婉晨.. 袁玫.. 王相印.. 张玉杰 ' target='_blank'> 戴萌娜.. 丰志强.. 尹文强 ' target='_blank'> 《现代预防医学》2022,(3):456-460
目的 分析山东省卫生资源配置地区差异性,为优化区域卫生资源配置提供参考。方法 采用熵权-TOPSIS(Entropy weight TOPSIS)法与秩和比(RSR)法综合评价2015—2019年山东省卫生资源配置情况。结果 根据熵权-TOPSIS法可得2015—2019年鲁东、鲁中、鲁西南地区卫生资源配置综合评价平均水平分别为0.403、0.520、0.264;RSR法分档结果为好( Ci >0.542)、中(0.092< Ci <0.542)、差( Ci <0.092)三类,其中鲁东地区在三档中占比为2/3、4/12、0;鲁中地区占比为1/3、3/12、1/2;鲁西南地区占比为0、5/12、1/2。方差分析结果显示 F =18.755, P <0.001,说明分档结果具有统计学意义。结论 山东省卫生资源配置存在明显地区差异,鲁东、鲁中地区卫生资源配置情况较好,鲁西南地区较差。政府应发挥主导作用,完善人才激励机制,缩小卫生资源区域配置差异,提高人群健康水平。 相似文献
40.
目的:了解利多卡因混合芬太尼-潘库溴铵静脉局部麻醉能否降低利多卡因的剂量。方法:80例前臂和手部手术患者(ASAⅠ-Ⅱ级)分成二组,用0.6ml/kg的0.25%利多卡因(1.5mg/kg)混合1ug/kg芬太尼-0.5mg潘库溴铵或者0.5%利多卡因(3mg/kg)进行静脉局部麻醉。每5min1次,测量感觉和运动神经阻滞时间至手术开始,手术结束,松开止血带后,每5min1次,测量感觉和运动神经恢复时间;记录术后镇痛时间,结果:两组患者均取得满意的麻醉效果,两组间感觉和运动阻滞起效有明显差异,A组明显快于B组(P<0.05),松开止血带后,感觉和运动恢复时间,两组相比无明显差异(P>0.05),术后镇痛时间,两组间亦无明显差异(P>0.05),结论:25%利多卡因混合芬太尼-劣库溴铵具有0.5%利多卡因相同的静脉局部麻醉效果,可减少局麻药剂量和潜在系统毒性。 相似文献