脂肪基质干细胞培养及其定向分化为成骨细胞、软骨细胞特性的研究

目的研究脂肪基质干细胞（adipose—derived stem cells，ADSCs）分离培养的方法，探讨大鼠ADSCs在体外向成骨细胞、软骨细胞分化的能力。方法从成年SD大鼠腹股沟处无菌获取脂肪组织，胶原酶消化分离，培养出ADSCs。基础培养基传至第二代时改换诱导培养基，分别诱导向成骨、软骨细胞分化，培养2～4周，碱性磷酸酶（alkaline phosphatase，ALP）、Vonkossa染色鉴定向成骨细胞分化能力；阿新蓝染色鉴定向软骨细胞分化能力。RT—PCR检测成骨细胞、软骨细胞标志基因。结果大鼠脂肪能够分离培养出生长旺盛的ADSCs；向成骨细胞诱导，ALP、Vonkossa染色阳性，RT—PCR检测有ALP、Osteocalcin及Osteopontin表达；向软骨细胞诱导，阿新蓝染色阳性，RT—PCR检测有Ⅱ型胶原、X型胶原和Aggreean表达。结论大鼠脂肪组织可以分离培养出ADSCs，生物学特性与骨髓基质干细胞（mesenchymal stemcells，MSCs）相似，能够向成骨细胞、软骨细胞分化，有希望成为组织工程理想的种子细胞来源。     

膝关节滑膜间质干细胞分离、培养及其多向分化潜能特性的研究

目的 探讨晚期骨关节炎患者膝关节滑膜间质干细胞(synovium-derived mesenchymalstem cells,SMSCs)体外分离、培养的可行性及其在体外向脂肪细胞、成骨细胞和软骨细胞定向分化的特性.方法 取膝关节滑膜组织,胶原酶消化获得有核细胞.挑选单细胞克隆,筛选获得SMSCs.流式细胞技术检测细胞表面特异性抗原标志.培养至第三代,分别向脂肪细胞、成骨细胞和软骨细胞诱导分化.油红O染色鉴定向脂肪细胞分化;碱性磷酸酶染色、茜素红染色鉴定向成骨细胞分化;甲苯胺蓝染色鉴定向软骨细胞分化.RT-PCR检测脂肪细胞、成骨细胞标志基因.Ⅱ型胶原免疫组化染色检测软骨细胞Ⅱ型胶原的表达.结果 原代SMSCs体外培养呈葵花样细胞集落,传代后可见圆形巨噬样细胞和纺锤形成纤维样细胞,融合后呈成纤维细胞样生长.CD44、CD90呈阳性,CD34、CD71和CD45呈阴性.向脂肪细胞诱导21d,油红O染色阳性;RT-PCR检测有脂蛋白酶、乙二腈及PPARγ2表达;向成骨细胞诱导7、28 d,ALP,茜素红染色阳性,有ALP、Osteopontin及Osteocalcin表达;向软骨细胞诱导21d,甲苯胺蓝染色阳性,Ⅱ型胶原免疫组化染色阳性.结论 晚期骨关节炎患者膝关节滑膜组织可以分离、培养获得SMSCs. SMSCs具有向脂肪细胞、成骨细胞和软骨细胞发生定向分化的潜能.     

自体富血小板血浆诱导兔脂肪干细胞成软骨分化的实验研究

[目的]体外分离、培养、鉴定兔脂肪干细胞,探讨富血小板血浆体外诱导脂肪干细胞成软骨分化潜能。[方法]取Ⅰ型胶原酶消化兔脂肪后,贴壁法分离培养脂肪干细胞,取第3代细胞分别予以成脂、成骨诱导,证实其多向分化潜能;同时取第3代细胞予以富血小板血浆诱导,2周后倒置显微镜观察细胞形态,行Ⅱ型胶原免疫荧光细胞化学染色、甲苯胺蓝染色和实时荧光定量PCR检测Ⅱ型胶原和聚集蛋白聚糖的表达。[结果]可以从兔脂肪中培养出脂肪干细胞,成脂、成骨诱导证实其多向分化潜能。经自体富血小板血浆诱导的脂肪干细胞,其Ⅱ型胶原免疫荧光细胞化学染色、甲苯胺蓝染色均为阳性。实时荧光定量PCR检测发现经自体富血小板血浆诱导的兔脂肪干细胞Ⅱ型胶原α1链基因和聚集蛋白聚糖基因表达明显高于对照组未经诱导的兔脂肪干细胞(P<0.01)。[结论]自体富血小板血浆可以有效诱导兔脂肪干细胞表达II型胶原和蛋白聚糖,可以诱导兔脂肪干细胞向软骨细胞方向分化。     

负载人骨形态发生蛋白-7基因的兔脂肪干细胞向成骨细胞分化的实验研究

目的 探讨人骨形态发生蛋白-7(hBMP-7)基因修饰对兔脂肪干细胞(ADSCs)成骨能力的影响. 方法 原代培养兔脂肪干细胞,免疫组织化学方法检测细胞表面抗原CD44、CD49d、CD106的表达,对细胞进行鉴定;阳离子脂质体介导hBMP-7基因转染ADSCs,绿色荧光蛋白表达观察转染效率、逆转录-聚合酶链反应(RT-PCR)检测目的基因hBMP-7的表达;ALP定量测定,Western blot检测Ⅰ型胶原、骨钙素的表达,以评价转基因ADSCs向成骨细胞分化的情况. 结果 从兔脂肪组织中分离出来的ADSCs CD44、CD49d表达呈阳性,CD106表达呈阴性.RT-PCR检测筛选后的ADSCs稳定表达hBMP-7.转染后7、10、14 d ALP定量测定转染组明显高于未转染组,差异有统计学意义(P<0.05);成骨标志物Ⅰ型胶原、骨钙素的表达转染组明显高于未转染组.结论 从脂肪组织中分离出的ADSCs是一种较好的组织工程种子细胞.hBMP-7重组质粒转染ADSCs后表达目的蛋白,并诱导ADSCs向成骨细胞分化.     

三种亚型软骨组织来源干细胞的分离培养及鉴定

目的分离培养猪不同亚型软骨组织(弹性软骨、透明软骨以及纤维软骨)来源干细胞并鉴定,为软骨组织工程提供理想种子细胞。方法利用纤维连接蛋白黏附法分别从猪耳软骨、关节软骨以及椎间盘软骨中分离培养干细胞,并进行传代。倒置相差显微镜下观察细胞形态变化,流式细胞术鉴定细胞表面抗原表达水平(阳性标志物CD29、CD90及阴性标志物CD34、CD45),单克隆形成实验鉴定软骨干细胞单克隆形成能力。三向诱导分化鉴定软骨来源干细胞的成软骨、成骨及成脂多向分化潜能。RT-PCR检测成骨(Ⅰ型胶原、Ⅹ型胶原)、成软骨[蛋白聚糖(Aggrecan)、II型胶原]、成脂[脂联素(Adiponectin)、脂肪酸合成酶(fatty acid synthase,FAS)]相关基因表达,并以猪BMSCs作为对照。结果通过纤维连接蛋白黏附法分别从耳软骨(弹性软骨)、关节软骨(透明软骨)、椎间盘软骨(纤维软骨)分选出一群细胞,细胞高表达干细胞表面阳性标志物CD29、CD90,几乎不表达干细胞表面阴性标志物CD34、CD45。经过体外2周培养,单个细胞均能形成细胞克隆。三向诱导分化显示软骨来源的干细胞具备成软骨、成骨和成脂分化能力。RT-PCR结果显示,成骨诱导后关节和椎间盘来源软骨干细胞的Ⅰ、Ⅹ型胶原基因相对表达量明显高于BMSCs(P0.05),耳软骨来源干细胞与BMSCs比较差异无统计学意义(P0.05);成软骨诱导后,3种亚型软骨组织来源干细胞Aggrecan、Ⅱ型胶原基因相对表达量均高于BMSCs(P0.05);成脂诱导后,3种来源软骨干细胞Adiponectin及FAS基因相对表达量均低于BMSCs,但比较差异无统计学意义(P0.05)。结论不同亚型的猪软骨组织中均存在软骨干细胞,具有干细胞的典型特征。     

兔骨髓基质细胞体外成骨分化鉴定及与煅烧骨复合培养的实验研究

目的研究兔骨髓基质细胞体外向成骨细胞分化的生物学特性及其与牛煅烧骨体外复合培养的生物相容性.方法将体外培养1周的兔骨髓基质细胞向成骨细胞诱导分化,于1、2、4周时提取RNA,采用RT-PCR技术检测ALP和I型胶原mRNA表达,并对培养2周的细胞行VonKossa染色观察钙结节形成;另制备细胞-煅烧骨复合物,继续培养1、7、14 d后取出,扫描电镜观察及X射线衍射仪检测.结果体外诱导培养2、4周后,兔骨髓基质细胞成功表达ALT和I型胶原,VonKossa染色可见钙结节形成.扫描电镜及X射线衍射分析证实细胞在煅烧骨表面大量贴附成活,14 d后细胞铺满支架表面,合成并分泌胶原纤维及钙盐.结论兔骨髓基质细胞体外可成功向成骨细胞诱导分化,成骨特性表达佳;与牛煅烧骨体外复合培养显示良好的生物相容性.     

人原发性骨关节炎与正常人关节软骨间充质祖细胞多向分化能力的对比研究

[目的]观察原发性骨关节炎及正常人关节软骨间充质祖细胞的生长和增殖特性及其成软骨、成骨和成脂分化能力,探讨关节软骨间充质祖细胞在原发性骨关节炎发病中的重要作用。[方法]观察原发性骨关节炎及正常人关节软骨间充质祖细胞成软骨(微团培养)诱导分化后的细胞形态变化,TB、Ⅱ型胶原、Aggrecan染色,GAG含量及Ⅱ型胶原mRNA表达;成骨(单层传代培养)诱导分化后细胞形态变化,钙结节染色,ALP活性及BGPmRNA表达;成脂(单层传代培养)诱导分化后细胞形态变化,油红染色,油红染色阳性细胞比率及TG含量。[结果]原发性骨关节炎及正常人关节软骨间充质祖细胞成软骨诱导分化后细胞TB、Ⅱ型胶原、Aggrecan染色均呈阳性,原发性骨关节炎者GAG含量减少及Ⅱ型胶原mRNA表达减弱(P<0.05);成骨诱导分化后细胞钙结节染色均呈阳性,原发性骨关节炎者ALP含量减少及BGPmRNA表达减弱(P<0.05);成脂诱导分化后细胞油红染色均呈阳性,原发性骨关节炎者TG含量增加(P<0.05)。[结论]关节软骨间充质祖细胞经成软骨、成骨及成脂诱导后均能分化为具有相应功能细胞特性的分化细胞。原发性骨关节炎关节软骨间充质祖细胞成软骨和成骨分化能力降低,而成脂分化能力增加,提示原发性骨关节炎关节软骨间充质祖细胞分化功能出现异常,骨关节炎关节软骨细胞对软骨损伤修复能力降低。     

人骨髓间充质干细胞体外成骨分化过程中成骨相关基因的动态表达

目的：系统研究人骨髓间充质干细胞（hBMSCs）体外成骨诱导分化过程中成骨相关基因的表达变化。方法：应用密度梯度离心法分离hBMSCs,取第2代细胞通过流式检测及多向诱导分化方法进行干细胞鉴定;应用RT-PCR法对hBMSCs在体外成骨诱导不同时间点的成骨相关基因表达进行检测。结果：第2代hBMSCs表达间充质干细胞表面标志CD44、CD90,具有成脂和成骨分化潜能。成骨相关基因在诱导早期部分表达,中期均有表达,基因表达大部分在14天达高峰,与矿化相关的基因表达在21天达高峰。结论：hBMSCs体外成骨诱导过程中成骨相关基因呈动态表达,其表达时序与成骨细胞生理发育基本相似。     

胰岛素样生长因子-1基因转染脂肪间充质干细胞向软骨细胞分化的研究

目的 观察胰岛素样生长因子(IGF)-1基因转染的脂肪间充质干细胞(ADSCs)向软骨细胞分化的效果.方法 原代培养兔ADSCs,免疫荧光法检测细胞表面抗原CD44、CIM9;脂质体介导人IGF-1基因转染兔ADSCs联合低浓度血清培养基向软骨细胞分化诱导,RT-PCR及Western blot方法检测IGF-1的表达,MMT法绘制细胞增殖曲线、甲苯胺蓝染色软骨结节、免疫组织化学检测Ⅱ型胶原的表达.结果 脂肪间充质干细胞CD44、CD109表达阳性,基因转染后细胞IGF-1表达阳性,细胞增殖速度增快,出现软骨结节,Ⅱ型胶原表达增高.结论 从脂肪组织中能够分离出增殖旺盛的ADSCs,IGF-1在ADSCs内获得稳定表达,细胞增殖能力增强,促进其向软骨细胞分化.     

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.