人前脑啡肽基因修饰人胚胎肾细胞的构建

目的 构建人前脑啡肽基因(hPPE)修饰的人胚胎肾细胞(HEK293细胞).方法 重组质粒pcDNA3.1(+)/hPPE经限制性内切酶HindⅢ和Not Ⅰ进行双酶切获得hPPE基因,运用基因重组技术将hPPE基因与表达载体同源重组,转染293T细胞进行慢病毒包装、扩增、纯化,测定病毒滴度,再将重组的慢病毒载体转染HEK293细胞.用Western blot法检测hPPE基因在HEK293细胞中的表达.结果 重组慢病毒载体阳性克隆测序结果和基因库的hPPE基因序列完全一致.含有hPPE基因的慢病毒载体,滴度为2.07×108TU/ml.转染慢病毒载体后的HEK293细胞,在荧光显微镜下未见到GFP荧光.转染Ubc-GFP-L.V.空病毒载体的HEK293细胞,可见到较强的荧光.Western blot法检测到经慢病毒载体转染后的HEK293细胞中hPPE基因表达呈阳性.结论 成功构建了hPPE基因修饰的HEK293细胞,使hPPE基因可在HEK293细胞中稳定表达.     

强力霉素调控表达脑啡肽的永生化大鼠星形胶质细胞株的构建

目的构建受强力霉素（Dox）调控表达脑啡肽的永生化大鼠星形胶质细胞株（IAST）。方法采用脂质体介导法将重组质粒pRevTREhPPE和调节质粒pRevTet-On分别转染逆转录病毒包装细胞PT67；将含有RevTet—On和RevTRE／hPPE病毒上清感染IAST，得到稳定表达脑啡肽的IAST／Tet-On／hPPE细胞株，实时定量PCR检测Dox定量调控该细胞株前脑啡肽原（hPPE）基因的表达，免疫细胞化学及放射免疫分析法检测Dox定量调控该细胞株中脑啡肽的表达。结果IAST／Tet-On／hPPE细胞株中，hPPE基因的表达和脑啡肽的分泌受Dox调控，Dox浓度为100～5000nedml时，随着Dox浓度增高，hPPE基因的表达和脑啡肽的分泌增加，Dox浓度为5000ng／ml时达峰值。结论成功构建了受四环素及其衍生物强力霉素定量调控表达脑啡肽的IAST。     

四环素调控系统修饰永生化大鼠星形胶质细胞株的构建及鉴定

目的构建四环素及其衍生物强力霉素诱导表达目的基因的永生化大鼠星形胶质细胞株。方法用脂质体法将逆转录病毒载体四环素调控系统中的质粒pRevTet-On转染病毒包装细胞 PT67,经筛选培养后获得病毒载体RevTet-On,采用RT-PCR进行鉴定,并应用NIH313细胞测定病毒滴度。将RevTet-On感染永生化大鼠星形胶质细胞,用有限稀释法挑选阳性细胞单克隆后扩大培养,每个克隆瞬时转染含萤光素酶报告基因的质粒pRevTRE-Lue,加入强力霉素48h后分别检测其萤光素酶活性值,挑选出强力霉素诱导表达高、背景表达低的细胞株并检测其诱导表达的时效、量效关系。结果 RT-PCR结果显示逆转录病毒包装成功,病毒最高滴度为7．4×105CFU／ml。RevTet-On转染永生化大鼠星形胶质细胞后挑选出48个单克隆,瞬时转染pRevTER-Luc后筛选出1株高表达低背景细胞株, 其诱导表达值为876．1 RLU,背景表达值为42．5 RLU,诱导倍数为20．6。该细胞株在加入诱导因子强力霉素1 h后目的基因即开始表达,在24 h时达到高峰,在强力霉素浓度100-2 000 ng/ml的范围内, 其诱导表达活性与药物浓度呈剂量依赖性。结论含四环素调控系统的永生化大鼠星形胶质细胞株诱导活性可靠,可用于调控表达外源基因的研究。     

重组人前脑啡肽原基因腺相关病毒载体的构建

目的 构建重组人前脑啡肽原基因(hPPE)腺相关病毒载体(AAV)。方法 构建质粒骨架上含有新霉素抗性基因表达盒的重组腺相关病毒(rAAV)载体质粒pSNAV-hPPE并酶切鉴定,转染金黄地鼠胚胎肾细胞(BHK 21),后用G418筛选培养形成稳定携带rAAV载体的混合细胞株BHK／SH1;再用HSV1-rc／△UI2感染、包装此细胞株并收获病毒载体rAAV-hPPE,并行DNA探针点杂交测定病毒滴度。结果 酶切鉴定pSNAV-hPPE重组成功,病毒滴度为2.5×1012v.g.／ml。结论 获得的rAAV-hPPE滴度高,感染性好,可以用于转基因镇痛的实验研究。     

pLXSN-GDNF重组载体的鉴定及其包装细胞系的建立

目的 鉴定携带大鼠胶质细胞源性神经营养因子（glial cell line—derived neurotrophic factor，GDNF）的重组逆转录病毒载体（pLXSN—GDNF），并建立包装细胞系。方法 采用脂质体包裹法进行pLXSN—GDNF质粒PA317细胞的包装、G418抗性筛选及病毒液提取，PCR及RT—PCR进行重组逆转录病毒的鉴定，NIH3T3细胞进行逆转录病毒颗粒滴度测定。结果 pLXSN-GDNF质粒测序结果与GeneBank中序列一致，所测DNA序列位于pLXSN多克隆位点Xho I。采用pLXSN—GDNF质粒转染包装细胞PA317，获得G418抗性细胞，RT—PCR证实其培养上清含有重组逆转录病毒，采用NIH3T3细胞测定病毒滴度为10^4～10^5CFU／ml。结论 pLXSN—GDNF结构正确，GDNF基因序列完整；并成功建立了pLXSN-GDNF的包装细胞系。     

人IL-1受体拮抗蛋白重组逆转录病毒载体的构建、鉴定及在骨关节炎软骨细胞中的表达

目的 构建含人IL-1受体拮抗蛋白(IL-1 receptor antagonist, IL-1Ra)逆转录病毒表达载体(PLXRN-IL-1Ra),体外转染人骨关节炎(osteoarthritis, OA)软骨细胞,研究其相关特性.方法 利用细菌内同源重组技术快速构建PLXRN-IL-1Ra逆转录病毒重组质粒,经测序及酶切鉴定正确后转染PT67细胞,包装成为重组PLXRN-IL-1Ra逆转录病毒,并使用小鼠肾成纤维细胞系NIH/3T3对病毒进行滴度测定.实验分为3组未转染组(A组)、PLXRN空质粒转染组(B组)、PLXRN-IL-1Ra转染组(C组),病毒感染人OA软骨细胞后,RT-PCR检测细胞内IL-1Ra基因的转录和表达;ELISA法检测细胞培养上清液中人IL-1Ra蛋白表达.结果 酶切鉴定及基因测序证实重组逆转录病毒质粒中含有人IL-1Ra cDNA,测定包装的病毒滴度为3 × 104 CFU/mL.原代软骨细胞体外培养呈多角形或梭形,甲苯胺蓝染色见细胞内有紫色异染颗粒.RT-PCR结果显示在C组出现311 bp人IL-1Ra mRNA片段,A、B组未见人IL-1Ra mRNA的表达带,GAPDH在各组均有表达.ELISA检测发现C组细胞上清有一定量的人IL-1Ra表达,蛋白浓度为(60.47±15.13)ng/L,A组和B组均无人IL-1Ra表达.结论 构建的IL-1Ra逆转录病毒表达载体成功地感染人OA软骨细胞,并在体外获得稳定表达,为将表达人IL-1Ra基因的人OA软骨细胞用于OA基因治疗提供了实验依据.     

新型人骨形成蛋白2逆转录病毒载体的构建及活性检测

目的 构建表达重组人骨形成蛋白2(BMP2)基因的重组逆转录病毒,对其在成骨细胞中的生物学作用进行探讨.方法 克隆BMP2基因,与pDNR-CMV连接构成pDNR-CMV-BMP2,然后将重组质粒pDNR-CMV-BMP2和逆转录病毒质粒pLP-LNCX以loxP位点进行同源重组,构成逆转录病毒载体pLP-LNCX-BMP2,转染包装细胞PT67进行病毒包装,NIH3T3细胞测定病毒滴度;将逆转录病毒感染人成骨细胞,噻唑蓝(MTT)法检测细胞生长变化,Western blot检测BMP2蛋白表达.结果 重组逆转录病毒载体pLP-LNCX-BMP2经鉴定连接正确;病毒载体pLP-LNCX-BMP2转染PT67后,上清液中病毒滴度可达到5×108pfu;MTT检测见逆转录病毒组与对照组比,48和72h细胞抑制率(5.1%比5.3%,8.5%比8.3%)差异无统计学意义(P>0.05),转染48 h后Westernblot可见BMP2蛋白高表达.结论 成功构建了BMP2逆转录病毒,为BMP2基因治疗及其功能研究提供了有效的手段.     

Stra8基因启动子逆转录病毒包装细胞株的建立

目的:建立小鼠Stra8基因启动子控制绿色荧光蛋白EGFP表达(P(stra8)-EGFP)的逆转录病毒包装细胞株,以方便地将P(stra8)-EGFP转导到目的细胞,为生殖细胞鉴定分选提供基础.方法:PCR扩增小鼠基因组DNA中的Stra8基因启动子片段,构建Stra8基因启动子控制表达的EGFP报告基因逆转录病毒质粒.将质粒脂质体法转染PT67病毒包装细胞,G418抗性筛选后,梯度稀释法将包装细胞单克隆化并扩增成多个细胞株.以包装细胞培养上清液感染NIH3T3细胞的所形成的G418抗性阳性细胞数定义病毒滴度,确定高滴度病毒包装细胞株.通过染毒小鼠骨髓间充质干细胞(mouse bone marrow mesenchymal stem cells,MSCs)验证该细胞株的P(stra8)-EGFP转导效果.结果:所建立的病毒包装细胞株培养上清液滴度达到1.3×10(6) cfu/ml.MSC经包装细胞培养上清液感染后,在(retinoic acid,RA)诱导下能表达EGFP蛋白.结论:成功构建了将P(stra8)-EGFP转导到目的细胞的PT67逆转录病毒包装细胞株.     

携带反义甲胎蛋白增强子/单纯疱疹病毒胸苷激酶基因的产病毒细胞系的建立及对肝癌细胞的靶向杀伤效应

目的建立对肝癌细胞具有靶向调控的高感染性和高分泌性产病毒细胞系。方法将重组反义甲胎蛋白增强子/单纯疱疹病毒胸苷激酶基因逆转录病毒载体(pL/TK/AFE/SN)转染至PA317包装细胞,经G418(400mg/L)筛选、病毒滴度测定。以病毒上清感染培养的Hep3B肝癌细胞和Hela宫颈癌细胞,并抽提细胞基因组DNA作Southernblot分析;观察GCV(100mg/L)对细胞生长的影响。结果转染pL/TK/AFE/SN的PA317细胞经G418筛选2周获阳性克隆;病毒滴度为5.4×104～3.8×105CFU/ml。Southern杂交证实前病毒已完整整合于PA317细胞,并稳定整合于Hep3B肝癌细胞和Hela宫颈癌细胞中。导入AFE/TK基因的Hep3B肝癌细胞经GCV作用后的存活率在2、4、6d时分别降低35%、87%、95%,生长明显受抑制(F=7.23,P<0.01)。结论携带AFE/TK基因的产病毒细胞系能够成功地将AFE/TK基因转移到感染细胞中。     

携带人降钙素基因相关肽基因的重组逆转录病毒的构建及鉴定

目的 构建、鉴定携带人降钙素基因相关肽α(hCGRPα)的重组逆转录病毒载体pLNCX2-hCGRPα.方法 采用基因工程技术,双酶切消化后回收438 bp的hCGRPα cDNA片段和6.1kb的pLNCX2载体片段,纯化后按摩尔比7∶1混合,将降钙素基因相关肽基因片段克隆至逆转录病毒载体pLNCX2上,序列测定、对比.鉴定后用脂质体法转染PT67细胞进行病毒包装扩增,感染NIH3T3细胞,观察细胞克隆,测定病毒滴度.结果 酶切、测序结果与hCGRPα基因重组逆转录病毒载体的预期结果一致,分别为6.1kb和438 bp,与空载体和目的基因大小相符.包装、扩增获得病毒滴度达1.7×106 pfu/ml,对NIH3T3细胞有较高的感染效率.结论 成功构建重组逆转录病毒pLNCX2-hCGRPα,为进一步的基因治疗研究奠定了实验基础.     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.