地塞米松对感染柯萨奇B-2病毒的人胚心肌细胞的保护作用

目的从细胞水平观察地塞米松对感染柯萨奇(CoxB_2)病毒的人胚心肌细胞的作用,从而对病毒性心肌炎患者应用激素治疗的问题作出评价。方法采用培养的人胚心肌细胞接种CoxB_2病毒,观察细胞生长、搏动情况及超微结构,测定心肌细胞释放的LDH活性。结果地塞米松治疗组的心肌细胞搏动较感染组者维持时间长,心肌细胞病变发展亦较缓慢,且LDH值明显低于感染组。结论地塞米松对感染CoxB_2病毒的人胚心肌细胞有明显的保护作用,提示临床上重症病毒性心肌炎,特别是早期阶段,应用激素有一定的治疗意义     

槐果碱对感染CVB3搏动心肌细胞的保护作用

目的：应用柯萨奇病毒B3(CVB3)感染SD大鼠乳鼠心肌细胞造成病毒性心肌炎模型,观察槐果碱对该模型的作用。方法：(1)将乳鼠心肌细胞分成4组：感染组,感染CVB3；治疗组,感染病毒后加入100mg·L~(-1)的槐果碱；同时设立药物对照组和细胞对照组。在处理的d 2,3,5观察各组细胞病变效应(CPE)、细胞搏动频率并测定细胞上清液中乳酸脱氢酶浓度。(2)将心肌细胞感染CVB3后加入不同浓度的槐果碱(12．5～400mg·L~(-1)),设立病毒、细胞及药物对照。在处理后d 2,3,5观察CPE并测定细胞上清中的乳酸脱氢酶(LDH)浓度。结果：(1)100mg·L~(-1)的槐果碱对感染CVB3的乳鼠心肌细胞有保护作用,治疗组的CPE较感染组减轻,上清液中的LDH浓度降低。(2)槐果碱在12．5～300mg·L~(-1)之间均对感染CVB3的乳鼠心肌细胞有保护作用,它可以减轻病毒导致的CPE,并减少LDH释放。在400mg·L~(-1)反而会加重CPE,增加LDH释放。结论：一定浓度的槐果碱在体外对感染CVB3的心肌细胞有保护作用。     

参麦注射液对感染柯萨奇B3病毒心肌细胞的影响

目的在细胞水平探讨参麦注射液（SMI）对实验性病毒性心肌炎的治疗作用。方法采用原代培养的SD大鼠心肌细胞感染柯萨奇B3病毒（CVB3）造成实验性病毒性心肌炎细胞模型;设立正常对照组、模型组、SMI高剂量（10g／L）组、SMI中剂量（5g／L）组及SMI低剂量（2．5g／L）组,观察心肌细胞感染CVB,后第3天和第5天的搏动频率、细胞病变、细胞超微结构、上清液中乳酸脱氢酶（LDH）的活性和CVB,滴度。结果感染CVB,后心肌细胞的搏动频率明显减慢;第5天模型组有半数细胞搏动停止,细胞病变明显,线粒体肿胀且形态不完整,内质网扩张,部分肌原纤维损坏,上清液中LDH的活性显著升高;SMI各剂量组心肌细胞均维持搏动,且高剂量组细胞病变程度、LDH活性和CVB,滴度均明显低于模型组,除部分肌原纤维损坏外,线粒体形态完整,内质网未见扩张。结论SMI对感染CVB,的培养心肌细胞搏动功能具有保护作用,并能降低心肌细胞上清液中CVB3滴度和减轻CVB,对心肌细胞的损伤。     

N-Acetylcysteine prevents but does not reverse dexamethasone-induced hypertension

1. We have shown previously that N-acetylcysteine (NAC) prevents the increase in blood pressure induced by adrenocorticotropin treatment. The present study investigated the effect of NAC on dexamethasone (Dex)-induced hypertension. 2. Male Sprague-Dawley rats were randomly divided into six groups (n = 10 in each). In a prevention study, NAC (10 g/L in the drinking water) was given for 4 days prior to and 11 days during concurrent treatment with saline (0.1 mL/rat per day) or with Dex (10 mg/rat per day). In a reversal study, daily injections of Dex or saline began 8 days before NAC and cotreatment continued for 5 days. Systolic blood pressure (SBP) was measured on alternate days using a tail-cuff system. 3. Dexamethasone significantly increased SBP from 113 +/- 4 to 139 +/- 6 mmHg (n = 10; P < 0.01). N-Acetylcysteine alone had no effect on SBP. In NAC + Dex-treated rats, SBP was significantly lower than that of Dex-treated rats (P cent < 0.01). In fully established Dex-hypertension NAC was ineffective and SBP remained high. 4. Both Dex and NAC treatments decreased bodyweight gain. N-Acetylcysteine reduced food and water consumption. Dexamethasone reduced thymus weight (P cent < 0.01) but NAC treatment did not alter this marker of glucocorticoid activity. 5. Dexamethasone tended to decrease plasma NO(x), whereas NAC restored plasma NO(x) concentrations to control levels. N-Acetylcysteine had no effect on Dex-induced increased plasma F(2)-isoprostane concentrations. 6. In conclusion, NAC partially prevented, but did not reverse, Dex-induced hypertension.     

The role of the pituitary in the development of electroacupuncture analgesia in rats

In order to investigate the involvement of pituitary beta-endorphin in electroacupuncture analgesia (EAA), the effects of hypophysectomy, dexamethasone (Dex) and adrenalectomy on the analgesia and the increase in plasma corticosterone (Cort) and ACTH levels produced by electroacupuncture (EA) were studied in male SD rats. In saline-treated and Dex-treated rats, plasma Cort levels were correlated with plasma ACTH levels. In non-treated rats, the time course of EA-induced increase in pain threshold was similar to that of EA-induced elevation of plasma Cort levels. In the hypophysectomized rats, EAA was significantly reduced and the EA-induced increase in plasma Cort was also abolished. Single administration of a large dose of Dex tended to reduce EAA and significantly reduced the EA-induced increase in plasma Cort and ACTH. Further suppression of pituitary functions by 4 days-treatment with Dex resulted in further reduction of EAA and the EA-induced increase in plasma Cort and ACTH. On the other hand, hind-paw pressure test without EA produced an increase in plasma Cort and ACTH to the same extent as that produced by EA and produced no analgesia. In the adrenalectomized rats, EAA was reduced, and the plasma ACTH level, which was sixteen times higher than that of nonoperated rats, was further elevated 2-fold higher by EA. No correlation between plasma ACTH levels and the increase in pain thresholds was observed in individual rats of the saline-treated and Dex-treated groups. Control pain thresholds were not influenced by hypophysectomy, Dex or adrenalectomy. These results suggest that pituitary beta-endorphin may not be mainly involved in EAA.     

丙泊酚联合雷米芬太尼复合麻醉期间右旋美托咪啶对BIS和AAI的影响

目的探讨丙泊酚靶控输注复合雷米芬太尼麻醉期间右旋美托嘧啶(Dex)对脑电双频谱指数(BIS)和听觉诱发电位指数(AAI)的影响。方法将230例行甲状腺全切除术的全麻患者按照随机数字表法均分为研究组和对照组,患者均输注丙泊酚和静脉泵注射雷米芬太尼,研究组给予静脉泵注生理盐水与Dex稀释药物,对照组给予等剂量的生理盐水,观察2组不同麻醉时刻BIS、AAI、MAP及HR的变化情况,同时监测患者生化指标变化。结果 (1)维持麻醉过程中,BIS和AAI值均逐步下降,使用右旋美托嘧啶20min后BIS值显著低于给药前,而AAI值变化不显著;(2)MAP:研究组中与t0时刻相比,t1、t2时刻MAP明显升高(P<0.05),t1、t2时刻MAP高于对照组,t3时刻低于对照组(P<0.05)。(3)HR:研究组中与t0时刻相比,t2、t3时刻HR明显升高(P<0.05);t2、t3时刻HR低于对照组(P<0.05);t0时刻检测显示,AST、ALT、ALB、TP和TBiL等生化指标组间差异无统计学意义,t3时刻研究组AST、ALT、ALB、TP和TBiL与t0时刻相比均降低,且均低于同时刻对照组水平(P<0.05),对照组AST、TBiLt3时刻与t0时刻相比降低(P<0.05)。结论丙泊酚靶控输注复合雷米芬太尼麻醉期间静脉泵注右旋美托嘧啶有助于患者降低BIS而保持AAI不发生明显变化,且麻醉20min维持MAP和HR在正常稳定状态。     

体外循环和不停跳冠脉搭桥术后早期肺功能的临床研究

目的：了解冠脉搭桥术后早期肺动力学指标的变化，比较体外循环和非体外循环心脏不停跳冠脉搭桥术对术后早期肺功能的影响。方法：对行体外循环与非体外循环不停跳冠脉搭桥术的28例冠心病患者的肺动力学指标、血气分析及某些临床指标进行检测。结果：冠脉搭桥术后早期患者均出现肺顺应性下降，气道阻力下降，两组比较，不停跳冠脉搭桥术后早期患者肺顺应性较高，动脉血氧分压较高，机械通气时间较短，且均有显著性差异（P＜0．05）。结论：冠脉搭桥手术对术后早期肺顺应性有不良影响，不停跳冠脉搭桥术对术后早期肺功能的影响较少，有利于改善患者的预后。     

Glucocorticoids enhance airway epithelial barrier integrity

Asthma is a chronic inflammatory disorder of the airways, but its pathogenesis is incompletely understood. While asthma is a complex disease caused by multiple factors, epithelial barrier damage is a cardinal feature. Glucocorticoids (GCs) are the most effective anti-inflammatory drugs in the treatment of asthma. However, the effects of GCs on the airway epithelial barrier have not been evaluated. Epithelial barrier functions were evaluated in cultured human airway epithelial cell monolayers, Calu-3 and 16HBE. Then, the cells were treated with dexamethasone (Dex), fulticasone propionate (FP), or budesonide (BD) for 5 days. Permeability measured by transepithelial electrical resistance was increased by treatment with Dex, FP, and BD in a dose-dependent manner. Permeability to fluorescein isothiocyanate-labeled dextran was markedly reduced by these treatments. Immunocytostaining revealed that Dex treatment potentiated tight junction formation in these polarized epithelial cells. Knockdown of epidermal growth factor receptor (EGFR) by small interference RNA blunted the effects of Dex on barrier integrity. Although EGFR expression was not affected by Dex treatment, EGFR phosphorylation was enhanced in Dex-treated cells. This is suggesting that EGFR are important for this phenomenon. These findings suggest that GC inhalation therapy can improve epithelial barrier integrity and might contribute to the therapeutic effects of GCs for treating asthma.