老年男性维生素D受体基因多态性与骨密度关系的研究

目的研究维生素D受体(vitamin D receptor,VDR)基因多态性在老年男性中的分布, 并进一步研究其与骨密度的关系。方法采用聚合酶链反应-限制性片段长度多态性(PCR- RFLP)方法,分析145例老年男性的VDR基因型,同时用双能X线吸收法测定腰椎及髋部骨密度。结果 VDR基因型分别为BB,0．014;Bb,0．117;bb,0．869。骨质疏松组与非骨质疏松组之间VDR基因型分布频率的差异无显著性(P>0．05)。比较各基因型组的骨密度,bb组及 Bb组只有在股骨颈处显示出BMD均低于BB组,差异有显著性(P<0．05),其它部位,三个基因型组的BMD均差异无显著性(P>0．05)。结论老年男性VDR基因型分布频率与某些西方国家人群分布不同,其VDR基因型与骨密度无明显相关性。VDR基因可能不是我们所研究群体 BMD的主要遗传基因。     

广西壮、汉族绝经后妇女维生素D受体基因型与骨密度的关系

目的 探讨维生素D受体基因(VDR)型在广西壮、汉族绝经后妇女中的分布及其与骨密度(BMD)的关系。方法 在广西居住20年以上、无血缘关系的健康绝经后妇女198名,其中三代均为壮族的116名,均为壮族的82名。记录他们的年龄、绝经年龄,测量他们的身高、体重。用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法测定受试者的VDR基因型;用双能X线吸收法测定髋部、腰椎和前臂的骨密度。结果 壮、汉两组妇女VDR基因型和VDR等位基因频率分布均无显著性差异(P>0.05);198名妇女BB、Bb、bb基因型检出率分别为6.57％、66.16％和27.27％;B、b等位基因分别为39.65％和60.35％。BB基因型组第二腰椎(L2)BMD较bb基因型组低10.03％(P=0.047),第四腰椎(L4)BMD分别较bb、Bb基因型组低9.63％(P=0.043)和12.44％(P=0.005)。BB基因型组骨质疏松发生率最高(46.15％),Bb基因型组次之(19.86％),bb基因型组最低(14.81％),差异有显著性(P=0.04)。结论 VDR基因型与广西壮、汉族绝经后妇女BMD有关联,BB基因型可能可作为预测广西壮、汉族绝经后妇女骨质疏松危险性的遗传学标志之一。     

维生素D受体基因型与骨密度

目的考察维生素D受体(VDR)基因多态性在我国汉族人群中的分布频率,分析VDR基因型与骨密度的关系.方法采用聚合酶链反应和限制性酶切技术检测100例绝经前健康妇女VDR基因多态性.应用双能X线骨密度仪检测受试者腰椎及髋部骨密度.结果VDR基因型分布频率为BB型4.0%,Bb型10.0%,bb型86.0%;而三种基因型受试者髋部及腰椎骨密度均表现出Bb＞bb＞BB,经F检验腰椎骨密度3基因型比较,P＜0.05,具有显著差异.结论绝经前妇女VDR基因型分布频率与西方及国内的一些报道不尽相同,且骨密度显示出Bb＞bb＞BB,亦与国内外一些研究结果不同.     

绝经后妇女桡骨远端骨质疏松性骨折相关因素的研究

目的 探讨绝经后妇女桡骨远端骨质疏松性骨折的危险因素,雌激素受体-α（ER-α）基因多态性与骨密度的关系.方法 以哈尔滨地区自然绝经后妇女108名为研究对象,采用问卷调查的方式,测量腰椎（L2-4）、股骨近端和桡骨远端的骨密度,分为桡骨远端骨质疏松性骨折组、骨质疏松症组和正常对照组.利用PCR-限制性片段长度多态技术检测ER-α基因的PvuⅡ和Xba Ⅰ的酶切多态性,分析基因多态性与骨密度之间的关系.结果 骨折组各部位骨密度均低于正常对照组各部位骨密度,差异有显著统计学意义（P＜0.01）,骨折组与骨质疏松症组各部位骨密度差异无统计学意义（P＞0.05）.Ca、P、AKP在不同组间无统计学意义（P＞0.05）.文化程度高、身高较高、月经初潮较早、钙制剂、牛奶饮用量、VD、体重指数大是桡骨远端骨质疏松性骨折的保护性因素,有统计学意义（P＜0.05）,绝经年龄早、绝经年限长、妊娠次数多、多产次、身高缩短为桡骨远端骨质疏松性骨折的危险因素,有统计学意义（P＜0.05）.ER-α基因PvuⅡ多态性与股骨颈、大转子及桡骨远端骨密度有统计学意义（P＜0.05）,PP基因型较Pp及pp型具有更低的骨密度值,差异有统计学意义（P＜0.05）,Xba Ⅰ多态性与骨密度无相关性（P＞0.05）.结论 文化程度高、身高较高、月经初潮较早、钙制剂、牛奶饮用量、VD、体重指数大是桡骨远端骨质疏松性骨折的保护性因素,绝经年龄早、绝经年限长、妊娠次数多、多产次、身高缩短为桡骨远端骨质疏松性骨折的危险因素.ER-α基因PvuⅡ多态性与股骨颈、大转子及桡骨远端骨密度具有相关性.     

甲状旁腺素和维生素D受体基因多态对糖尿病患者骨密度的影响

目的探讨甲状旁腺素(PTH)基因多态性与中国北方汉族人糖尿病患者骨密度的关系,联合分析维生素D受体(VDR)基因和PTH基因多态性与骨密度的相关性。方法选自青岛市内分泌糖尿病医院1998年1月~2002年1月住院的糖尿病患者,运用聚合酶链反应限制性片段长度多态性(PCR-RFLP)技术检测了1型糖尿病(T1DM)组54例,2型糖尿病(T2DM)组104例,健康对照(CON)组102例,260例中国北方汉族人PTH基因多态性;采用双能X线吸收法骨密度仪(DEXA)测量骨密度。结果校正年龄和BMI后,1型糖尿病组腰椎、股骨颈骨密度低于对照组(P0.05);2型糖尿病组与对照组相比,骨密度差异无显著性(P0.05);甲状旁腺素(BSTB1位点)基因型和等位基因分布频率在1型糖尿病组、2型糖尿病组与对照组间差异无显著性(P0.05);在对照组及2型糖尿病组,BB基因型者腰椎(L2-4)和股骨颈部位骨密度显著高于Bb/bb基因型(P0.05);在1型糖尿病组,BB基因型仅腰椎L2-4部位骨密度高于Bb/bb基因型(P0.05);联合VDR基因多态(Apa I酶切位点)分析结果表明,Bbaa基因型在腰椎和股骨颈骨密度低于其他基因型(P0.05)。结论糖尿病患者PTH基因多态性(BSTB1位点)可能是预测骨量减少、骨质疏松易感性的遗传标志。联合VDR基因多态(Apa I酶切位点)有助于识别糖尿病患者发生骨质疏松的高危人群。     

广州汉族成年人维生素D受体基因分布及其与骨密度关系的研究

目的　了解中国广州地区人群VDR基因多态性的分布及其与骨密度的关系。方法　选取居住广州地区的汉族成年人 396例。应用PCR RFLP等生物学技术检测VDR基因 ,用双能X线骨密度仪 (DEXA)对入选的大部分对象进行了全身、腰推正侧位 ,股骨近端BMD检测。结果　VDR基因分布频率是BB 6 5 %、Bb 4 8 2 %、bb 4 5 3% ;本组对象峰值骨量出现在 30～ 39岁组 ,并且以Bb基因型的BMD值最高 ;3种基因型按BMD大小排列顺序为 :Bb >BB >bb ,但只有Bb与bb两基因型的BMD存在着差异。结论　①VDR基因多态性与种族、居住地区和人群不同有关。②峰值骨量出现在 30～39岁组 ,以Bb基因型对应较高的BMD ,bb基因型对应较低的BMD。③VDR基因型与BMD间存在着关联 ,但对其骨质疏松相对高危人群的预测价值有待进一步的深入研究。     

长春市汉族女性维生素D受体基因BsmⅠ和FokⅠ位点多态性与骨密度相关性研究

目的研究长春市35~85岁汉族女性维生素D受体(vitamin D receptor,VDR)基因Bsm Ⅰ、Fok Ⅰ位点的多态性,并分析其与骨密度(bone mineral density,BMD)的相关关系。方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术分析Bsm Ⅰ和Fok Ⅰ酶切位点多态性,采用Hologic Discovery WA型骨密度仪检测腰椎正位(L1~4)BMD。将230例受试者分成绝经组和未绝经组,观察两组各基因型分布特征,应用SPSS 19.0软件对试验结果进行统计分析。结果在本研究人群中,Bsm Ⅰ位点基因型分布情况为bb占83.9%、Bb占12.6%、BB占3.5%,b等位基因频率高达90.2%,B等位基因频率为9.8%;Fok Ⅰ位点基因型分布情况为ff占18.3%、Ff占43.9%、FF占37.8%,f等位基因频率为40.2%,F等位基因频率为59.8%,两位点基因型分布均符合Hardy-Weinberg定律(χ2=1.283,P=0.125;χ2=0.96,P=0.342);未绝经组与绝经组各基因型分布组间差异无统计学意义(P0.05);Bsm Ⅰ位点在未绝经组和绝经组中各基因型BMD无差异(P0.05);Fok Ⅰ位点ff型BMD较FF型和Ff型低,但在未绝经组中差异无统计学意义(P0.05),绝经组中ff型与FF型比较,BMD差异有统计学意义(P0.05)。结论在本研究的230例35~85岁汉族女性人群中,Bsm Ⅰ位点基因型分布以bb型为主,b等位基因频率高达90.2%,各基因型骨密度无差异;Fok Ⅰ位点ff型有较低的BMD,但在未绝经组中差异无统计学意义,在绝经后女性中ff型与低BMD相关。     

雌激素受体α和维生素D受体基因多态性与哈尔滨地区绝经后妇女骨密度的关系

目的探讨哈尔滨市绝经后妇女雌激素受体α(ER-α)基因和维生素D受体(VDR)基因多态性与骨密度的关系。方法对哈尔滨市81例无亲缘关系汉族健康妇女进行PCR-RFLP测定ER-α基因PvuⅡ、XbaⅠ多态性和VDR基因BSMⅠ多态性,用双能X线吸收法测定骨密度(BMD)。结果本研究人群PP、Pp及pp基因型频率分别为13.6%、49.4%、37.0%;XX、Xx及xx基因型频率各为4.9%、40.7%、54.4%;BB、Bb及bb基因型频率各为0%、16.0%、84.0%,t检验分析各基因型与BMD值的关系显示:绝经后妇女中,雌激素受体基因型仅与腰椎骨密度有显著差异。维生素D受体基因型在股骨颈、大转子部位有显著差异。PvuⅡ多态性和BSMⅠ多态性共同作用对骨密度影响更大。结论雌激素受体、维生素D受体基因型分布频率均符合Hardy-Weinberg定律,并且与骨密度有一定的关联,尤其是基因与基因的共同作用与骨密度的关系更为密切。     

骨质疏松相关基因的研究进展

骨质疏松(osteoporosis,OP)在很大程度上受基因的影响。在OP的相关基因中,维生素D受体(VDR)基因、雌激素受体(ER)基因、Ⅰ型胶原基因及转化生长因子基因都是重要的候选基因。VDR基因中BB基因型者比Bb及bb基因型者的腰椎骨密度(bone mineral density,BMD)低,骨丢失率高。FokⅠ基因型与腰椎BMD降低有明显相关性,ff基因型者腰椎BMDXx基因型者>xx基因型者。Ⅰ型胶原基因与骨量呈显著相关性,COLIA1基因突变可致低骨量、骨脆性增加。转化生长因子β(TGF-β)基因对调节骨形成和骨吸收有重要作用,TGF-β基因中可发生碱基丢失,这种变异多见于OP患者。     

上海地区汉人维生素D受体基因多态性与骨密度关系的初步分析

目的：了解维生素D受体（VDR）基因多态性在中国人群中的分布，并进一步研究其与骨密度的关系。方法：通过聚合酶链反应－限制性片段长度多态性（PCR－RFLP）方法分析了348例无亲缘关系的上海地区男女居民的VDR基因型，并用双能X线吸收仪测定了其中202例骨密度。结果：348例研究对象中bb型占81．9％，Bb型占18．1％，未见到BB型。b等位基因在本组人群中分布 高达90．0％。男女性之间VDR基因型分布频率无明显区别（P＞0．5）。比较这两组各部位的骨密度值，只有女性在华氏三角区部位显示出Bb型比bb型有较高的BMD，在其余部位，不管男性还是女性，两组基因型的BMD均差异无显性（P＞0．05）。结论：VDR基因多态性与骨密度无相关关系。     

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.     

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.     

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.