血液回收对非体外循环冠状动脉旁路移植患者红细胞和血液粘度的影响

目的观察血液回收技术对非体外循环冠状动脉旁路移植患者红细胞、血小板和血液粘度的影响。方法2005年8月~2007年10月间,共完成46例非体外循环冠状动脉旁路移植术,随机分为实验组(血液回收组)和对照组(不使用血液回收机组),每组23例。观察两组用血液制品的数量和术后24h的引流量,比较两组术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度。结果实验组用浓缩红细胞和血浆的量明显少于对照组,两组术后24h引流量、术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度之间的差异无显著性意义。结论血液回收技术在非体外循环冠状动脉旁路移植患者中能减少输血,对红细胞、血小板和血液粘度无不利影响。     

Filter properties of root mean square successive difference (RMSSD) for heart rate

The root mean square successive difference (RMSSD) in heart period series is a time domain measure of heart period variability. The RMSSD is sensitive to high-frequency heart period fluctuations in the respiratory frequency range and has been used as an index of vagal cardiac control. By transfer function simulations, the RMSSD statistic is shown to represent a high-pass filter that effectively captures respiratory sinus arrhythmia but also passes lower frequency fluctuations that can include sympathetic influences. These simulations, together with analysis of actual heart period series, reveal that the RMSSD is biased by basal heart period. Although between-subjects levels of RMSSD covary highly with spectral estimates of high-frequency variability, within-subject RMSSD change scores account for only 50-60% of the variance in spectral estimates. The present findings raise caveats in the applications and interpretation of the RMSSD statistic.     

额窦筛窦向眶顶气化的应用解剖

目的:观察额窦、筛窦气房向眶顶气化情况。方法:对60具成人尸体头部标本额窦、筛窦向眶顶气化进行解剖观察,并结合全部标本的鼻窦冠状位CT扫描了解气化情况。结果:120侧标本气化眶顶骨板的有36.7％(44侧),其中气化整个眶顶者36.4％(16侧),气化部分眶顶者63.6％(28侧),气化眶顶的前颅底骨质内侧缘及外侧缘骨壁厚度分别为(0.3±0.1)mm(0.1-0.4mm)和(0.2±0.1)mm(0.1-0.3mm),无气化的前颅底骨质骨壁厚度为(0.9±0.3)mm(0.4-1.8 mm);CT扫描显示额窦、筛窦向眶顶气化结果与解剖观察一致。结论:了解额窦、筛窦气房向眶顶气化情况对预防鼻微创手术颅内及眶内并发症有重要的临床意义。     

上颌窦窦口的形态观察及其临床意义

目的：为了指导鼻内窥镜下功能性上颌窦手术。方法：对６０个头部标本（男３４，女２６）１２０侧进行了上颌窦口及其毗邻结构的观察测量。结果：上颌窦鼻通道的鼻开口口径为平均３．８ｍｍ，上颌窦通道长度为５．６ｍｍ，鼻内开口到前鼻棘连线与鼻底平面夹角为４５．２°，前鼻棘至鼻内开口的距离为３７．０ｍｍ，下鼻甲前端至鼻内开口距离为１９．５ｍｍ，中鼻甲前端至鼻内开口距离为１４．６ｍｍ。结论：上颌窦窦口为管状通道，该处的病变可以导致窦腔炎症，可以进行内窥镜下窦口扩大术，术中应避免损伤眼眶及鼻泪管。     

Baroreflex control of jejunal blood flow and fluid transport in cats; effects of yohimbine,an α.-adrenergic antagonist

The aim of the study was to test the hypothesis that baroreceptor unloading increases jejunal fluid absorption rate via an α₂-adrenergic effect on electrogenic active transport. In 13 chloralose-anaesthetized cats, the carotid sinus baroreceptors were isolated and perfused with arterial blood, and we studied the effects of a graded decrease in carotid sinus pressure on intestinal vascular resistance, net fluid absorption rate and the potential difference between the intestinal lumen and the peritoneal cavity (PD). Experiments were performed in seven control animals and in six animals pretreated with yohimbine, an α₂-adrenergic antagonist, at a dose of 0.1 mg kg^-I i.v. Yohimbine per se had no significant effects on systemic arterial pressure, intestinal vascular resistance, net fluid absorption rate or PD. In the control animals, baroreceptor unloading induced an increase in systemic arterial pressure, intestinal vascular resistance and net fluid absorption rate, and a decrease in the PD. Yohimbine pretreatment did not significantly affect the systemic blood pressure response to baroreceptor unloading, but abolished the effect on intestinal vascular resistance and PD. After yohimbine treatment, decreases in carotid sinus pressure still enhanced net fluid absorption rate, but this response was observed in a higher range of carotid sinus pressures than in control animals. We conclude that (1) a major component of the increase in jejunal absorption rate during baroreceptor unloading is due to a non-electrogenic mechanism, which may be either active or passive; (2) this component of the response is not blocked by yohimbine at a dose sufficient for an effect on presynaptic α₂-receptors; (3) the absorptive response to baroreceptor unloading is not a phenomenon secondary to the concomitant jejunal vasoconstriction.     

Cardiovascular indices of physiological arousal in boys with fragile X syndrome

In this study, the relationship between physiological arousal, as indexed by heart rate variability, was examined in boys with fragile X syndrome (FXS) and typically developing boys matched on chronological age. In addition, the relationship of heart activity to clinical and molecular factors in the group of boys with FXS was examined. Results suggest that boys with FXS have higher levels of heart activity during the passive phases, as reflected in shorter heart periods. This high level of heart activity appears to be due to increased sympathetic activity and reduced parasympathetic activity. Boys with FXS did not display the expected patterns of heart activity in response to phases of increasing challenge, and sympathetic and parasympathetic systems did not appear coordinated in these boys with FXS. Clinical factors may be related to neural regulation of heart activity while molecular factors do not appear to be.     

急性上颌窦炎实验动物模型的建立

目的:拟建立急性上颌窦炎的实验动物模型,并探讨窦口的阻塞和致病菌的毒力在急性上颌窦炎的发病机制中的地位。方法:第一天,阻塞单侧窦口,对侧做假手术。次日,注入0.5ml108CFU/ml肺炎链球菌悬浮液。第五天处死动物、观察、分离培养细胞、取材和制作切片。结果:阻塞上颌窦口和注入肺炎链球菌的联合组,鼻部症状明显;进食量减少;鼻窦粘膜水肿、微红,具有较多脓性分泌物,微血管扩张,白细胞浸润;肺炎链球菌的重新分离培养率为100％（与其余组比较具有显著意义P<0.01）。而仅阻塞上颌窦口或仅注入肺炎链球菌或假手术均无明显临床症状及组织病理学改变,细胞培养率也低。结论:窦口的阻塞和致病菌的毒力是上颌窦炎发生发展的重要的条件,其中,窦口的阻塞起着关键性作用;联合阻塞窦口并注入有荚膜的肺炎链球菌能较理想地建立急性上颌窦炎实验动物模型。     

Hostility and sex differences in the magnitude, duration, and determinants of heart rate response to forehead cold pressor: Parasympathetic aspects of risk

Recent models hypothesize that hostility confers increased risk of CHD through weaker parasympathetic dampening of cardiovascular reactivity (CVR). We tested this possibility using the forehead cold pressor task, a common maneuver which elicits the “dive reflex” characterized by a reflexive decrease in HR presumably through cardiac-parasympathetic stimulation. Participants were initially chosen from the outer quartiles of a sample of 670 undergraduates screened using the hostility subscale of the Aggression Questionnaire ([Buss, A.H., Perry, M., 1992. The Aggression Questionnaire. Journal of Personality and Social Psychology, 63, 452-459.]). The final sample of 80 participants was evenly divided between men and women and high and low hostility. Following a 10-min baseline, participants underwent a 3-min forehead cold pressor task. The task evoked a significant HR deceleration that was mediated by PNS activation, as assessed by respiratory sinus arrhythmia (RSA). Replicating prior research, men displayed greater decrease in HR. More important, low hostiles maintained larger HR deceleration over time compared to high hostiles although the autonomic basis for this effect was unclear. The findings broaden understanding of hostility and sex-related cardiovascular functioning and support the task as a method for evoking PNS-cardiac stimulation.