关键词： alpha-adrenergic receptors   cerebral autoregulation   cerebral blood flow   phentolamine   transcranial Doppler  

摘要： Background: Cerebral vasoconstriction without concurrent changes in systemic arterial blood pressure has been observed in both normal individuals and those with idiopathic orthostatic intolerance following several minutes of postural stress when circulating catecholamines are elevated. Therefore, we tested the hypothesis that alpha-adrenergic activation with and without elevated circulating norepinephrine (NE) directly affects cerebrovascular tone in healthy individuals. Methods: Mean arterial pressure (MAP;tonometry) and cerebral blood flow velocity (MFV) in the middle cerebral artery (transcranial Doppler) were measured in seven healthy individuals during 15 min periods of saline and of 5 0 (low NE) and 10 0 (high NE) ng kg(-1) min(-1) infusions of NE. Following this, phentolamine (PHO) was administered to return MAP back to baseline while high NE infusion continued (high NE + PHO). Finally, NE infusion was stopped allowing the persistent effects of PHO to dominate. Results: Circulating NE caused a dose-dependent increase in MAP (P<0(.)05). During combined high NE + PHO, blood pressure was initially reduced to baseline levels but then increased a second time (P<0(.)05) during the final similar to5 min of this phase. MFV remained constant during both low NE and high NE. In contrast, the secondary increase in BP during the late high NE + PHO phase was associated with elevated MFV. Cerebral vascular resistance (CVR) increased during high NE but was reduced to baseline during both early and late portions of the combined high NE + PHO phase (i.e. despite the late-phase increase in blood pressure). Conclusions: The increase in CVR during NE infusion was explained by an autoregulatory response to the increased blood pressure and not an alpha-mediated constriction. However, PHO appeared to interfere with the normal autoregulatory response to increasing blood pressure.

摘要： Background: EGD with conscious sedation is a safe procedure, but complications such as hypoxia can occur. The efficacy and safety of low-dose flunitrazepam (0.25 mg) was compared with a standard dose of flunitrazepam (0.5 mg) for moderate sedation during EGD. Methods: In a randomized, double-blind, placebo-controlled trial, 75 outpatients (40 men, 35 women, mean age 45 [11] years) undergoing screening EGD were randomly assigned to one of 3 treatment arms: 0.25 mg of flunitrazepam (F0.25 group), 0.5 mg of flunitrazepam (F0.5 group), or placebo (normal saline solution), each administered intravenously. Patient tolerance was scored by using self-assessment questionnaires with visual analogue scales. Cardiopulmonary complications were assessed by monitoring blood pressure, heart rate, oxygen saturation, and the electrocardiogram during the procedure. Results: The patient tolerance scores in the F0.25 and F0.5 groups, respectively 2.1 (2.1) and 2.3 (2.5), were significantly lower than that for the placebo group (6.5 [3.0]);there was no significant difference between F0.25 and F0.5. Cardiopulmonary complications in the F0.25 group were significantly lower than in the F0.5 group. Oxygen desaturation (oxygen saturation < 90%) was noted in two of 25 patients in the F0.5 group. Post-procedure drowsiness was observed in two of 24 (8.3%) patients in the F0.25 group and 3 of 21 (14.3%) in the F0.5 group (p = 0.2438). Conclusions: Patient tolerance of EGD with low-dose flunitrazepam (0.25 mg intravenously) was similar to that with a standard dose (0.5 mg intravenously) and significantly better than in the placebo group. Oxygen desaturation was observed only in the group that received the standard dose, suggesting that sedation with low-dose flunitrazepam is efficacious and safe for EGD.

关键词： CONSCIOUS sedation   SEDATIVES   ENDOSCOPY  

摘要： OBJECTIVE: Propofol, a rapidly-acting hypnotic agent, is increasingly being used for endoscopic sedation. Serious adverse effects, including respiratory and cardiovascular depression, make many endoscopists reluctant to use propofol in critically ill patients. This study characterizes propofol's safety profile in consecutive high-risk patients (American Society of Anesthesiologists [ASA] classes III and IV) compared with matched subjects (ASA classes I and II). METHODS: During a 19-month period, 1370 at risk-patients were sedated with propofol, of whom 47% (614 ASA III, 28 ASA IV) were age matched with 642 consecutive patients of the same gender and age assigned to ASA classes I and H and undergoing the same endoscopic procedures (395 gastroscopies, 201 colonoscopies, 14 combined). Registered nurses performed all sedations by propofol dose titration while carefully monitoring arterial oxygen saturation, heart rate, and blood pressure. RESULTS: No major complications occurred among the critically ill patients. There was, however, an increased risk for a short relevant oxygen desaturation (<90%) of 3.6% for ASA Ill and IV versus 1.7% for ASA I and Il (p = 0.036). In four versus one case, short mask ventilation was necessary. Also, a greater proportion of patients showed a >= 5% oxygen saturation decrease. There was no pronounced influence on arterial pressure or heart rate and no perforations in 336 colonoscopies. CONCLUSIONS: With careful monitoring, propofol sedation during GI endoscopies is safe, even for high-risk patients. Considering their higher comorbidity and tendency toward oxygen desaturation, they need particularly careful monitoring, and the required dose is, on mean, 10-20% lower than in ASA classes I and II.

关键词： 自我意识   脑   物理基础   辨证唯物主义   精神活动   人   皮亚杰   心理活动  

摘要： 人类“自我”意识产生的物理基础是什么 ?意识的本质究竟是什么 ?近年来 ,脑科学的迅猛发展在一定程度上回答了这些问题。本文通过对科学家发现了控制“自我”意识的大脑区域这一医学新成果的分析 ,考察了历史上有关意识问题的多种理论的局限性 ,揭示了该成果蕴含的哲学意义是对辩证唯物主义关于“人脑是产生意识的物理基础”内容的补充。

关键词： 弗洛伊德   意识形态理论   “意识形态”   马克思主义   本质   相同   丰富   “文化”   区别   角度  

摘要： 弗洛伊德的“文化”具有相同于“意识形态”的功能 ,尽管弗洛伊德的理论与马克思的历史唯物主义理论之间有着本质的区别。但弗洛伊德对文化的研究能为我们对于马克思主义意识形态理论的研究提供新的角度 ,补充和丰富马克思主义的意识形态理论。

摘要： Background: Patients undergoing EUS usually receive intravenously administered sedative medication. A double-blind, prospective, randomized trial was conducted to compare midazolam with a placebo for EUS of the esophagus and stomach and to assess patient tolerance and endoscopic feasibility. Methods: A total of 111 patients were randomized to receive midazolam or a placebo. Patients used a visual analogue scale to score pre-EUS anxiety and tolerance for the procedure. Endoscopists used a visual analogue scale to score ease of echoendoscope introduction and overall patient cooperation. Subsequent to EUS, patients were asked if they were willing to undergo the procedure under the same conditions. Results: The patients' visual analogue scale scores indicated that tolerance for the introduction of the echoendoscope and the procedure overall were both significantly better in the midazolam group. Overall patient tolerance was predicted by sedation (p < 0.001) and pre-EUS anxiety (p = 0.024). Endoscopists' visual analogue scale scores showed that ease of echoendoscope introduction was significantly better in the midazolam group. There was no significant difference in overall patient cooperation during the procedure. There were no significant differences in introduction time, total procedure time, or patients' willingness to undergo the procedure under the same conditions. Conclusions: EUS of the esophagus and stomach without intravenous sedation is feasible for endoscopists and patients. Patients prefer intravenous administration of midazolam. Assessment of anxiety before EUS may indicate whether administration of midazolam can improve tolerance for the individual patient.

关键词： GLUCONEOGENESIS   GLUCAGON   ADRENALINE  

摘要： Epinephrine increases net hepatic glucose output (NHGO) mainly via increased gluconeogenesis, whereas glucagon increases NHGO mainly via increased glycogenolysis. The aim of the present study was to determine how the two hormones interact in controlling glucose production. In 18-h-fasted conscious dogs, a pancreatic clamp initially fixed insulin and glucagon at basal levels, following which one of four protocols was instituted. In G + E, glucagon (1.5 ng . kg1 . -1; portally) and epinephrine (50 ng . kg1 . -1; peripherally) were increased; in G, glucagon was increased alone; in E, epinephrine was increased alone; and in C, neither was increased. In G, E, and C, glucose was infused to match the hyperglycemia seen in G + E (~250 mg/dl). The areas under the curve for the increase in NHGO, after the change in C was subtracted, were as follows: G = 661 +- 185, E = 424 +- 158, G + E = 1,178 +- 57 mg/kg. Therefore, the overall effects of the two hormones on NHGO were additive. Additionally, glucagon exerted its full glycogenolytic effect, whereas epinephrine exerted its full gluconeogenic effect, such that both processes increased significantly during concurrent hormone administration. [PERIODICAL ABSTRACT]

关键词： 意识形态   国家   国家形态   控制   知识经济   经济的知识  

摘要： 在知识经济时代和改革开放的今天,政治体制改革迫在眉睫,从理论上弄清楚国家与意识形态的关系,弄清楚国家如何利用科学知识和意识形态控制自然界和社会,控制人的意识等问题,具有非常迫切的理论和现实意义。本文试图以马克思的唯物史观为基础,谈谈对这些问题的看法。

关键词： 钢琴慢练   钢琴学习   意识控制   钢琴教学   钢琴弹奏   手指动作   弹奏技巧  

摘要： 钢琴慢练是解决钢琴学习中的困难最有效途径之一,也是弹好钢琴的必经之路。其真谛在于通过速度的放慢,手指动作的减缓去加强大脑意识的控制能力,使手指动作完全服从于有目的的意识控制。

关键词： ANGIOTENSIN-receptor blockers   BAROREFLEXES   HEART beat   ARGININE   SODIUM nitroferricyanide  

摘要： This study reports the effects of angiotensin II (ANG II), arginine vasopression (AVP), phenylephrine (PE), and sodium nitroprusside (SNP) on baroreflex control of heart rate in the presence and absence of the area postrema (AP) in conscious mice. In intact, sham-lesioned mice, baroreflex-induced decreases in heart rate due to increases in arterial pressure with intravenous infusions of ANG II were significantly less than those observed with similar increases in arterial pressure with PE (slope: 3.0 plus or minus 0.9 vs. 8.1 plus or minus 1.5 beats). Baroreflex-induced decreases in heart rate due to increases in arterial pressure with intravenous infusions of AVP were the same as those observed with PE in sham animals (slope: 5.8 plus or minus 0.7 vs. 8.1 plus or minus 1.5 beats). After the AP was lesioned, the slope of baroreflex inhibition of heart rate was the same whether pressure was increased with ANG II, AVP, or PE. The slope of the baroreflex-induced increases in heart rate due to decreases in arterial blood pressure with SNP were the same in sham- and AP-lesioned animals. These results indicate that, similar to other species, in mice the ability of ANG II to acutely reset baroreflex control of heart rate is dependent on an intact AP. [PUBLICATION ABSTRACT]