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51.
When a person moves through the world, the associated visual displacement of the environment in the opposite direction is not usually seen as external movement but rather as a changing view of a stable world. We measured the amount of visual motion that can be tolerated as compatible with the perception of moving within a stable world during active, sinusoidal, translational and rotational head movement. Head movements were monitored by means of a low-latency, mechanical head tracker and the information was used to update a helmet-mounted visual display. A variable gain was introduced between the head tracker and the display. Ten subjects adjusted this gain until the visual display appeared stable during sinusoidal yaw, pitch and roll head rotations and naso-occipital, inter-aural and dorso-ventral translations at 0.5 Hz. Each head movement was tested with movement either orthogonal to or parallel with gravity. A wide spread of gains was accepted as stable (0.8 to 1.4 for rotation and 1.1 to 1.8 for translation). The gain most likely to be perceived as stable was greater than that required by the geometry (1.2 for rotation; 1.4 for translation). For rotational motion, the mean gains were the same for all axes. For translation there was no effect of whether the movement was inter-aural (mean gain 1.6) or dorso-ventral (mean gain 1.5) and no effect of the relative orientation of the translation direction relative to gravity. However translation in the naso-occipital direction was associated with more closely veridical settings (mean gain 1.1) and narrower standard deviations than in other directions. These findings are discussed in terms of visual and non-visual contributions to the perception of an earth-stable environment during active head movement.  相似文献   
52.
Programmed myocyte cell death and activation of the immune system have been shown to occur in patients with congestive heart failure. Besides, unstable angina episodes are likely to be associated with immune activation. Our aim was to evaluate the role of changes in circulating levels of soluble Fas (sFas), suggestive of an enhanced inhibitory response to ongoing apoptosis, and soluble IL2 receptor (sIL2-R), indicative of T-lymphocyte activation, in chronic heart failure and unstable angina pectoris. Thirty patients affected by chronic heart failure (20 idiopathic and 10 ischemic cardiomyopathy) and 13 patients with unstable angina were evaluated. Twenty healthy individuals matched for age and gender were used as controls. A complete biochemical determination of indexes of myocardial damage including cardiac troponin I (cTnI) and creatine kinase (MB/CK) was performed. The results demonstrated that mean levels of sFas and sIL2-R were significantly increased in patients affected by chronic heart failure and unstable angina and were not associated with changes in renal function or with serum levels of cTnI. Highest values of sFas were found in NYHA class IV patients (IV NYHA class = 7.39 ± 0.52 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and more elevated in idiopathic than in ischemic cardiomyopathy (3.64 ± 0.40 vs. 1.82 ± 0.37 ng/ml; P < 0.01). Moreover, in chronic heart failure patients sFas and ejection fraction were negatively correlated (P = 0.01), whereas sFas and sIL2-R were positively correlated (P < 0.01). In unstable angina patients too, sFas and sIL2-R appeared to be correlated (P = 0.03); whereas sFas (angina group = 3.18 ± 0.39 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and sIL2-R (angina group = 0.46 ± 0.11 vs. controls = 0.00 UI/ml; P < 0.01) were higher in angina group than in controls. In most of the cases, the increase of sFas was associated with comparable changes in sIL2-R serum levels, indicating that the activation of Fas system is strictly associated with autoimmune–inflammatory reactions. This phenomenon, both in chronic heart failure and in unstable angina, occurs in the absence of biochemical evidences of myocardial damage and seems to parallel the activation of T cell. Soluble Fas could have a role in sustaining inflammatory response and in prolonging the detrimental effects correlated with it in chronic heart failure and angina pectoris.  相似文献   
53.
This study investigated the percentage of carbohydrate utilization than can be accounted for by glucose ingested during exercise performed after the ingestion of the potent lipolysis inhibitor Acipimox. Six healthy male volunteers exercised for 3 h on a treadmill at about 45% of their maximal oxygen uptake, 75 min after having ingested 250 mg of Acipimox. After 15-min adaptation to exercise, they ingested either glucose dissolved in water, 50 g at time 0 min and 25 g at time 60 and 120 min (glucose, G) or sweetened water (control, C). Naturally labelled [13C]glucose was used to follow the conversion of the ingested glucose to expired-air CO2. Acipimox inhibited lipolysis in a similar manner in both experimental conditions. This was reflected by an almost complete suppression of the exercise-induced increase in plasma free fatty acid and glycerol and by an almost constant rate of lipid oxidation. Total carbohydrate oxidation evaluated by indirect calorimetry, was similar in both experimental conditions [C, 182, (SEM 21); G, 194 (SEM 16) g · 3 h–1], as was lipid oxidation [C, 57 (SEM 6); G, 61 (SEM 3) g · 3 h–1]. Exogenous glucose oxidation during exercise G, calculated by the changes in13C:12C ratio of expired air CO2, averaged 66 (SEM 5) g · 3 h–1 (19% of the total energy requirement). Consequently, endogenous carbohydrate utilization was significantly smaller after glucose than after placebo ingestion: 128 (SEM 18) versus 182 (SEM 21) g · 3 h–1, respectively (P < 0.05). Symptoms of intense fatigue and leg cramps observed with intake of sweet placebo were absent with glucose ingestion.In conclusion, we found glucose ingestion during 3-h exercise with lipolysis blockade could provide metabolic substrate permitting a significant sparing of endogenous carbohydrate and consequently an improvement in performance.  相似文献   
54.
本文分别用抗人E受体、抗T_H、Ts细胞单抗的Ea花结抑制试验检测孕血清中EPF活性并对其进行了动态观察,同时检测了EPF活性与HCG-β、AFP、孕酮的关系以及对T淋巴细胞亚群的影响。结果说明:孕血清中EPF活性明显高于对照组(P<0.001)。孕血清中EPF活性主要通过对T_H细胞的作用实现。在孕早期EPF活性较高,随孕期延长活性逐渐下降,至孕6个月活性渐趋消失,分娩前10周基本消失。EPF活性与血中HCG-β、AFP浓度无关,与孕酮呈负相关。EPF不能直接抑制淋巴细胞的花结形成,但能显著地增强ATS、anti-CCT_3、anti-CD_4的花结抑制效应。  相似文献   
55.
对黄杨碱治疗的62例冠心病心绞痛甲襞微循环变化进行观察。结果表明:96.8%(60/62)的病例甲襞微循环有异常改变,且病情愈重其改变愈明显。用该药4.5mg/日(1.5mg,tid)治疗60天结果显示:绝大多数微循环异常指标都获改善(P<0.05~0.01),并认为该药有部分类似茛菪类药物的作用。对少数严重病例的异常微循环改善不明显。心绞痛缓解率及心电图(ST、T)改善率分别在70%以上及50%~70%之间。面药对降高明固醇及高甘油三酯作用不明显(P>0.05),而对升高高密度脂蛋白具有较好疗效(P<0.05)。该药无明显毒副作用。  相似文献   
56.
Twenty-four patients with stable exercise-induced angina pectorisentered a double-blind cross-over study. Isosorbide-5-mononitrate(5-ISMN) 60 mg in a controlled release formulation (Durules®)given once daily was compared with identical placebo. The exercisetolerance was determined by bicycle ergometry before and 3 hafter a single dose of 5-ISMN and following one week's treatmentwith 5-ISMN and placebo. Nineteen patients completed the study.Exercise tolerance until the onset of chest pain and until 1mm ST segment depression increased significantly 3 h after dose.The same increase was seen both after a single dose and thesame dose under steady-state conditions. No increase was seenwith placebo. The heart rate and systolic blood pressure reactionsin the standing position were less pronounced 3 h after dosein steady-state than after a single dose of 5-ISMN. Headachewas the only bothersome side-effect reported. The study demonstratesthat 60 mg 5-ISMN in a Durules® formulation given once dailyhas a significant anti-anginal effect and that tolerance doesnot develop.  相似文献   
57.
Summary A randomized, placebo-controlled, double-blind crossover investigation in 12 patients with non-asthmatic chronic obstructive lung disease and co-existing stable angina pectoris was done to compare two 1-selective adrenoceptor blocking agents, atenolol 100 mg and bisoprolol 20 mg. Systolic and diastolic blood pressures (SBP, DBP), heart rate (HR) as well as airway resistance (AWR, and less frequently forced expiratory volume in 1 s (FEV1) and intrathoracic gas volume (ITGV) were measured in the sitting position before and at various times up to 24 h after drug intake.During the first 4 h both beta-blockers produced a significant reduction in HR in comparison to placebo (p<0.01). Atenolol 100 mg significantly increased AWR relative to placebo and bisoprolol (p<0.05). After 24 h, a significant reduction in HR (p<0.01) could only be demonstrated after bisoprolol, whereas atenolol alone led to a significant elevation in AWR relative to placebo and bisoprolol (p<0.05) at that time.It is concluded that bisoprolol appears to have a high degree of beta1-selectivity, thus providing a wide split between beta1- and beta2-adrenoceptor blockade. Bisoprolol in its therapeutic dose range is expected to be relatively safe as regards bronchoconstriction in patients suffering both from hypertension and/or angina pectoris and chronic obstructive lung disease.  相似文献   
58.
目的:运用中医传承计算平台V3.0软件,研究王行宽教授治疗胸痹心痛遣方用药规律,传承王行宽教授诊疗胸痹心痛的学术经验。方法:收集整理2017—2020年王行宽教授于湖南中医药大学门诊诊疗冠心病心绞痛患者的原始病历资料,录入中医传承计算平台V3.0,运用软件进行方药规律研究。结果:共收集王行宽教授治疗胸痹心痛处方1 044则,所用药物多为甘、苦药物,归经以肺经为主,其次为心、脾、肝、胃、肾经;所用方剂中使用最多的经方是生脉散,最高的经验方是心痛灵Ⅲ号方;高频数药物主要有麦冬、半夏、丹参、瓜蒌皮、黄连、五味子、柴胡等药物;药物的常用剂量多为3、5、10、15 g;组方规律分析得到常用药组合129个,置信度>0.99的组合有58个,并得到常见证型核心药物;药物聚类得到6个核心药物组合。结论:王行宽教授论治胸痹心痛以益气养营、豁痰化瘀、疏肝利胆为治疗思路,并根据胸痹心痛不同证型予以辨证施治,体现其“多脏调燮、综合治理”的学术思想,其核心处方可供临床从业者参考,但仍需要进一步的临床及实验研究验证其疗效。  相似文献   
59.
目的 探讨梗死前心绞痛对急性心肌梗死溶栓治疗及近期预后的影响。方法 本文将 98例急性Q波心肌梗死病人 ,按梗死前 4 8h内心绞痛的有无 ,分为AP( +)和AP( - )组 ,分别观察两组溶栓再通率、CPK峰值、达峰时间、坏死Q波导联数、住院期间心力衰竭、恶性心律失常、心源性休克的发生率、病死率 ,出院时室壁瘤及左室射血分数。结果 两组均有显著性差异。结论 梗死前心绞痛对急性心肌梗死有潜在的治疗意义 ,可影响预后。  相似文献   
60.
目的 :观察心痛安颗粒剂对不稳定性心绞痛患者血小板和凝血系统的作用。方法 :6 0例不稳定性心绞痛患者随机分为心痛安组 (30例 ,常规西药加心痛安颗粒剂治疗 )与对照组 (30例 ,单用常规西药治疗 ) ,观察治疗前后血小板最大聚集率 (Ma% )血小板 α颗粒膜糖蛋白 (GMP- 140 )和 D-二聚体 (D- D)的变化。结果 :治疗后 ,心痛安颗粒组的 Ma% ,GMP- 140和 D- D经治疗后明显下降 ,下降幅度明显大于对照组。结论 :心痛安颗粒剂可能通过抑制血小板聚集、活化和纤维蛋白合成而发挥治疗不稳定性心绞痛的作用。  相似文献   
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