戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响

目的 探讨戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响.方法 雄性Wistar大鼠36只,体重250～300 g,随机分为4组(n=9):对照组(Ⅰ组)、肢体缺血再灌注诱发肺损伤组(Ⅱ组)、小剂量盐酸戊乙奎醚组(Ⅲ组)和大剂量盐酸戊乙奎醚组(Ⅳ组).Ⅱ组、Ⅲ组和Ⅳ组麻醉后双后肢缺血3 h,Ⅲ组和Ⅳ组分别于股动脉开放前10 min肌肉注射盐酸戊乙奎醚2、9 mg/kg,再灌注4 h快速取肺,计算肺组织湿/干重比(W/D),透射电镜下观察肺组织超微结构,酶联免疫吸附法测定肺组织肿瘤坏死因子-α(TNF-α)和白细胞介素(IL)-10含量.结果 与Ⅰ组比较,Ⅱ组肺组织W/D及TNF-α、IL-10含量升高(P<0.01);与Ⅱ组比较,Ⅲ组肺组织W/D及TNDF-α含量降低、IL-10含量升高(P<0.01);与Ⅲ组比较,Ⅳ组肺组织W/D及TNF-α含量降低、IL-10含量升高(P<0.01).结论 戊乙奎醚可减轻肢体缺血再灌注诱发大鼠肺损伤,且呈剂量依赖性,其机制与降低肺组织炎性反应有关.     

Watching emotional movies: Affective reactions and gender differences

Previous studies have found that unpleasant film clips depicting mutilated bodies or injuries evoke a sustained heart rate deceleration which has been interpreted as reflecting a stimulus-specific aversive response or as increased orienting and attentional processing that varies with stimulus significance. Few studies, however, have examined cardiac changes during the viewing of high arousal pleasant films. To clarify this issue, the present study assessed evaluative, facial and autonomic reactions in both men and women during the viewing of highly arousing pleasant, as well as unpleasant, films. Results indicated a similar skin conductance increase and heart rate deceleration which were greater than those observed during the viewing of a neutral film. Compared to men, women rated both films as less pleasant and rated the unpleasant film as more arousing. The present findings suggest that sustained exposure to pleasant and unpleasant stimuli elicit similar cardiac orienting when stimuli are equated for subjective report of emotional arousal.     

羟羧氧酰胺菌素临床副反应

本文观察了使用羟羧氧酰胺菌素治疗肺部感染的患者14例,其每日用量为4.0克,持续用药1—2周。结果表明,治疗后有8例出现了不同程度的血液系统异常改变,肝肾功能未见明显异常。文章分析了该药引起血液系统异常的原因,并提出了应用该药时应注意的事项。     

Effect of ipratropium bromide on respiratory mechanics in infants with acute bronchiolitis

The effect of nebulized ipratropium bromide in 14 infants (mean age:20 weeks, range:4–41) with acute respiratory syncytial virus bronchiolitis was examined. A modified rapid chest compression technique was used to obtain partial expiratory flow-volume curves and maximum flow at functional residual capacity. Passive respiratory mechanics were assessed by brief occlusion at end inspiration. Thoracic gas volume was measured in a body plethysmograph. No significant difference was found in forced and passive respiratory mechanics pre- and post-ipratropium bromide. No subgroups could be identified. These results do not support the use of ipratropium bromide in acute viral bronchiolitis.     

Effects of Added Breathing Resistance on Respiratory Pattern during Mild and Moderate Exercises

In six healthy male subjects, the changes of respiratory airflow rate and heart rate were de-termined in sensory units of five just noticeable difference (JND) steps caused by inspiratory resistive (IR) loads ranging 0.28-1. 62 kPa.L~(-1) s and physical stimuli in IR corresponding to JND steps andcombined resistance (CR) of different ratios equivalent to 2, 4 JND sensation at rest and duringmild and moderate muscular exercises (250 and 500 kgm·min~(-1)) performed on a bicycle ergometer.The results suggest that the tendency of effects on respiratory pattern, within the test range of IRloads, are approximately consistent at rest and during mild and moderate exercise, that when theCR load is carried, the changes of respiratory pattern at rest and during mild exercise are similar,but more apparently during moderate exercise, and that the heart rote only increases with the rise ofexertion intensity, without apparent influence of resistive loads.     

Lung mechanics,gas exchange,pulmonary perfusion,and hemodynamics in a canine model of acutePseudomonas pneumonia

Acute bilateral hemorrhagic pneumonia was induced in 6 dogs (pneumonia group) by endotracheal inoculation withPseudomonas aeruginosa. Measurements of lung mechanics, gas exchange, distribution of pulmonary blood flow, and hemodynamics were made prior to inoculation and 5 hr later when pneumonia was established. These findings were compared to the same measurements in 6 other dogs inoculated with a sterile broth (control group). While there were no significant changes in lung mechanics in the control group, pneumonia caused a significant and proportional reduction (42%) in total lung capacity (TLC) and functional residual capacity (FRC). Although tidal lung compliance was reduced in the pneumonia group, neither the specific compliance nor the deflation pressure-volume curve, with lung volume expressed as a percentage of observed TLC, changed significantly. Pneumonia caused marked hypoxemia with a mean increase in shunt and venous admixture of 35% and 52%, respectively, while the control group developed only minimal abnormalities in gas exchange. Perfusion of the consolidated lung region, determined by radioactive microspheres and expressed as a percentage of total pulmonary blood flow, showed a small but significant decrease from baseline (53±13%) to established pneumonia (44 ±14%), while no change in lobar perfusion was seen in the control group. Only the infected animals showed significant changes in hemodynamics with a rise in cardiac output and fall in mean systemic arterial pressure and vascular resistance. We conclude that acute experimentalPseudomonas pneumonia causes reduction of FRC by filling of alveoli with inflammatory exudate and further reduction of TLC by preventing these alveoli from inflating at higher lung volumes without evidence for a change in the elastic properties of the remaining inflated lung; marked hypoxemia caused by maintenance of perfusion of consolidated lung with reduced or absent ventilation; and a hyperdynamic septic hemodynamic state similar to that seen in humans.     

Protective effects of pretreatment with Radix Paeoniae Rubra on acute lung injury induced by intestinal ischemia/reperfusion in rats

Objective： To investigate the effect of pretreatment with Radix Paeoniae Rubra （RPR） on acute lung injury induced by intestinal ischemia/reperfusion in rats and its protective mechanism.
Methods： Thirty-two Wistar rats were randomly divided into four groups： Sham-operation group, ischemla/ reperfusion group （I/R group ）, RPR-pretreatment group and hemin group. The model of intestinal ischemia/ reperfusion was established by clamping the superior mesenteric artery for 1 hour followed by 2-hour reperfusion. The effect of RPR on the expression of heme oxygenase-1 （HO-1） in lung tissues was detected by immunohistochemistry and morphometry computer image analysis. Arterial blood gas analysis, lung permeability index, malondialdehyde （MDA） and superoxide dismutase （SOD） contents in lungs were measured. The histological changes of lung tissue were observed under light microscope.
Resalts： The expression of HO-1 in RPR-pretreatment group and hemin group was obviously higher than that in sham-operation group and I/R group （ P 〈 0.01 ）. The level of MDA and lung permeability index in RPR-pretreatment and hemin group were significantly lower than those in I/R group （P〈0.01 or P〈0.05）, while the activity of SOD in RPR-pretreatment and hemin group was obviously higher than that in I/R group （P〈0.01）. Under light microscope, the pathologic changes induced by I/R were significantly attenuated by RPR.
Conclusion： Intestinal ischemia/reperfusion may result in acute lung injury and pretreatment with RPR injection can attenuate the injury. The protective effect of RPR on the acute lung injury is related to its property of inducing HO-1 expression and inhibiting lipid peroxidation.     

慢性阻塞性肺疾病并发呼吸衰竭相关危险因素分析

目的 探讨慢性阻塞性肺疾病(COPD)并发呼吸衰竭相关危险因素和预后因素.方法 对2005年3月至2008年2月收治的110例COPD患者的临床资料进行回顾性分析,根据是否发生呼吸衰竭分为呼吸衰竭组(40例)和非呼吸衰竭组(70例).结果 呼吸衰竭组每年急性发作次数、尿酸、总蛋白、白蛋白、体重指数与非呼吸衰竭组比较差异有统计学意义[分别为(5.54±1.16)次/年比(2.75±0.78)次,年、(283.75±72.49)mmol/L比(359.87±41.50)mmol/L、(58.77±1.54)g/L比(63.95±2.04)g/L、(36.15±1.08)g/L比(36.96±1.48)g/L、(20.33±0.99)kg/m2比(21.16±1.36)kg/m2](P<0.01);COPD分度、院内感染、酸碱平衡紊乱两组比较差异有统计学意义(P<0.05或<0.01).呼吸衰竭死亡患者和好转患者动脉血氧分压比较差异无统计学意义(P>0.05),pH值、动脉血二氧化碳分压、血钠、血氯比较差异有统计学意义(P<0.01).结论 COPD并发呼吸衰竭相关危险因素多.     

Force-time integral does not improve predictability of cardiac O2 consumption from pressure-volume area (PVA) in dog left ventricle

Summary We have proposed the systolic pressure-volume area (PVA) as a measure of the total mechanical energy generated by ventricular contraction, and we found a closely linear correlation between PVA and cardiac oxygen consumption (V_{O 2}). Although the force-time integral (FTI) has long been considered to be the most reliable correlate of cardiac oxygen consumption (V_{O 2}), we have already shown that V_{O 2} remained constant although FTI was changed while PVA was kept constant in the excised, cross-circulated dog left ventricle. This means that PVA is superior to FTI as a predictor of V_{O 2}. In the present study, we studied whether a linear addition of FTI to PVA could improve the prediction of V_{O 2} from PVA in isovolumic and ejecting contractions with different afterload pressures in the same type of dog left ventricle preparation. Although left ventricular V_{O 2} was always closely correlated with either PVA (r=0.967, mean after z-transformation) or FTI (mean r=0.925), multiple regression analysis indicated that PVA alone accounted for as much as 94% (mean) of the variance of V_{O 2} and that FTI linearly added to PVA accounted for an additional few percent of the variance (statistically significant in less than half the cases). We conclude that the addition of FTI to PVA does not improve the predictability of V_{O 2} from PVA in ordinary contractions.     

A theoretical and experimental model of ventricular interdependence

Summary Because of the close anatomical association between the ventricles, the volume of one ventricle can directly affect the volume and pressure within the other ventricle. To study the mechanical coupling between the ventricles, we modeled the right and left ventricles as a two-compartment model with right wall (C_iw), septal (C_s), and left wall (C_lw) compliances. Based on the balances of forces across the septum, four equations were obtained to predict the transfer of pressure (P) and volume (V) information from one ventricle to another. The validity of the theoretical analysis was tested first in a physical model and then in a post-mortem heart preparation. The standard errors of estimate comparing the predicted to measured values were low for both the physical model and the post-mortem heart data. All values were significantly related (P<0.05) with r>0.89. The results show excellent correlation between predicted and measured values. This model provides a better understanding of ventricular interdependence and may help to predict effects of hypertrophy and/or myocardial ischemia on ventricular interdependence.This study was supported in part by PHS NIH Grant Nos. HL31644 and HL22843. Dr. Santamore is a recipient of an NIH Research Carrer Development Award No. H101026