膀胱移行细胞癌中Survivin与Ki-67、p53的表达及临床意义

目的 探讨膀胱移行细胞癌中Survivin、p53及Ki-67的表达与膀胱移行细胞癌临床病理特征的关系及其临床意义. 方法 用免疫组织化学方法 检测88例膀胱移行细胞癌与10例正常膀胱黏膜组织中Survivin、p53及Ki-67的表达,并用RT-PCR方法 验证其中30例膀胱移行细胞癌和10例正常膀胱黏膜组织中Survivin的表达. 结果 免疫组织化学方法 显示在膀胱移行细胞癌中Survivin、p53阳性表达率分别为63.6%(56/88)和45.5%(40/88),正常膀胱黏膜组织中均无表达,差异有统计学意义(P<0.01),且Survivin的表达与膀胱癌的临床分期密切相关(P<0.05).膀胱癌组织中Ki-67增殖指数(PI)为20.4士10.7,正常膀胱黏膜组织中为0.RT-PCR方法 显示在30例膀胱移行细胞癌中Survivin阳性表达率为100%,而正常膀胱黏膜组织中均无表达.结论 Survivin与膀胱癌的恶性程度有关,与p53及Ki-67共同参与了膀胱移行细胞癌的发生、发展及进程.     

基质金属蛋白酶-9和脆性组氨酸三联体基因在人类膀胱移行细胞癌中的表达及其意义

目的 探讨基质金属蛋白酶-9(MMP-9)和脆性组氨酸三联体基因(FHIT)在膀胱移行细胞癌组织中的表达、相互关系和临床意义.方法 采用免疫组织化学链霉菌抗生物素蛋白-过氧化物酶(SP)法观察50例膀胱移行细胞癌石蜡标本和10例正常膀胱组织中MMP-9和FHIT的表达.结果 50例膀胱癌组织中的FHIT和MMP-9的阳性表达率分别为58.0％和52.0％,与正常膀胱组织中的表达比较差异有统计学意义(P＜0.05和P ＜0.01).FHIT和MMP-9的表达与膀胱移行细胞癌的临床分期、病理分级和肿瘤的复发相关;肿瘤组织中的FHIT与MMP-9的表达呈负相关(r=-0.412,P＜0.01).结论 膀胱癌组织中FHIT和MMP-9的表达在肿瘤进展中发挥重要作用.     

Survivin和富含亮氨酸重复序列免疫球蛋白2在人膀胱移行细胞癌组织中的表达及临床意义

目的 探讨Survivin和富含亮氨酸重复序列免疫球蛋白2(LRIG2)基因及其产物在人膀胱移行细胞癌中的表达及临床意义 方法 应用免疫组织化学检测72例膀胱癌组织病理标本中的Survivin和LRIG2的表达,每例标本均选用癌组织中心、癌旁组织及其远端正常黏膜对照.结果 免疫组织化学显示Survivin蛋白在正常膀胱黏膜中无表达,在膀胱癌组织中表达明显高于癌旁组织,阳性率分别为90.28％ 、33.33％,Survivin蛋白在膀胱癌不同病理分级中的阳性表达率分别为G1组72.22％、G2组90.48％、G3组100.00％;在膀胱癌临床分期Ta～ Tis、T1～T2的阳性表达率分别81.25％、97.50％;在淋巴结转移组和非淋巴结转移组的阳性表达率为96.00％、85.11％,随着病理分级、临床分期的升高和淋巴结转移的出现,Survivin蛋白表达水平逐渐升高,各组间差异有统计学意义(P＜0.05);LRIG2在膀胱移行细胞癌中的阳性表达率显著低于癌旁组织和正常膀胱黏膜组织,并随组织病理分级、分期的增高和淋巴结转移的出现,LRIG2阳性表达率逐渐下降,差异有统计学意义(p＜0.05);提示Survivin和LRIG2表达呈负相关(r=-0.487,P＜0.01).结论 Survivin和LRIG2基因表达与膀胱移行细胞癌的分级、分期、淋巴结转移有关,Survivin过表达和LRIG2基因突变或缺失在膀胱移行细胞癌的发生发展中可能起重要作用.     

血管生成素-2在膀胱移行细胞癌中的表达及意义

目的　初步探讨血管生成素 2 (Ang 2 )在膀胱移行细胞癌组织中的表达及其与临床分期、病理分级的关系。方法　应用免疫组织化学S P法检测 4 3例初治膀胱癌及 2 8例正常膀胱组织中的Ang 2表达水平 ,并与临床资料对照进行统计分析。 结果　正常膀胱组织中未见Ang 2阳性染色 ;4 3例膀胱移行细胞癌中Ang 2阳性染色者 2 1例 ,Ang 2在许多膀胱癌细胞和癌组织中微血管内皮上呈强阳性染色 ,且染色率随膀胱癌病理分级、临床分期的上升而升高 (P <0 .0 5 )。结论　①Ang 2促进肿瘤新生血管形成 ,参与膀胱癌的发生和发展。②Ang 2的表达与膀胱移行细胞癌的临床分期、病理分级正相关。     

凋亡抑制因子Livin在膀胱移行细胞癌组织中的表达及意义

目的：研究凋亡抑制蛋白家族(IAP家族)新的凋亡抑制因子Livin在膀胱移行细胞癌(BTCC)中的表达及其与肿瘤分级、分期、复发之间的关系。方法：采用免疫组织化学SP法,对54例BTCC和8例正常膀胱组织中Livin的表达情况进行检测,分析其在膀胱癌组织和非膀胱癌组织中的表达及其与肿瘤病理学分级、临床分期和患者复发情况的关系。结果：Livin在8例正常膀胱组织中均不表达,而在54例膀胱移行细胞癌组织中表达率为85．2%(P＜0．01)。Livin的表达和膀胱移行细胞癌的病理分级、临床分期、是否复发无明显相关(P＞0．05)。结论：细胞凋亡抑制因子Livin在BTCC组织中表达上调,提示Livin可能通过抑制细胞凋亡,对BTCC的发生发展起重要作用;Livin在膀胱癌中的高表达有望成为一种有效、敏感的瘤标,并为BTCC的基因治疗提供新的靶点。     

维甲酸受体β在膀胱移行细胞癌中的表达及意义

目的探讨维甲酸受体β（retinoic acid receptor-beta,RAR-β）在膀胱移行细胞癌中表达的意义。方法应用免疫组织化学方法检测80例膀胱移行细胞癌组织标本中RAR-β的表达。病理分级：Ⅰ级26例,Ⅱ级22例,Ⅲ级32例;临床分期：T120例,T220例,T322例,T418例;其中复发性膀胱癌46例。以10例正常膀胱组织作为对照。结果10例正常膀胱粘膜组织中RAR-β均为强阳性表达。80例膀胱移行细胞癌中RAR-β阳性表达28例（35.0%）。RAR-β表达在病理分级Ⅰ级以及临床分期T1、T2期膀胱癌中表达较高;在复发性与非复发性膀胱移行细胞中的表达分别为17.4%和58.9%,差异显著（P〈0.05）。结论RAR-β在膀胱移行细胞癌组织中存在表达缺失,其表达缺失程度与肿瘤病理分级、临床分期及复发相关,有作为膀胱移行细胞癌预后指标的可能。     

环氧化酶-2基因在膀胱移行细胞癌组织中的表达及其意义

目的　探讨环氧化酶 2 (COX 2 )基因在膀胱移行细胞癌组织中的表达及其临床意义。方法　采用免疫组织化学酶标记链霉素亲和生物素法 (LSAB)对 78例膀胱移行细胞癌组织进行COX 2基因表达的检测。结果　在膀胱癌中COX 2主要呈胞核表达 ,染色阳性率为 5 6.41% ;COX 2表达与膀胱移行细胞癌组织分级、分期和预后呈高度正相关 (P <0 .0 1)。结论　膀胱移行细胞癌中COX 2异常表达与肿瘤分级、分期和疾病进展等生物学行为密切相关。     

O6-甲基鸟嘌呤-DNA甲基转移酶在膀胱移行细胞癌中的表达及临床意义

目的：研究O^6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）在膀胱移行细胞癌（TCCB）组织中的表达及其与临床病理特征的关系。方法：应用免疫组织化学SP法检测60例膀胱移行细胞癌中MGMT的表达,统计分析其与肿瘤临床病理的关系。结果：膀胱癌组织中MGMT阳性表达率为35．0％（21／60）,明显低于癌旁组织（76．7％．46／60）及正常膀胱组织（86．7％,13／15）（P〈0．015;MGMT蛋白的表达与膀胱移行细胞癌组织分化程度有关（P＜0．05）。而与临床分期无明显关系。结论：MGMT在膀胱移行细胞癌的发生和发展中起抑制作用;MGMT蛋白的表达可能是预断膀胱癌预后的重要指标。     

膀胱移行细胞癌中凋亡相关蛋白survivin及caspase3的表达及相关性

目的探讨凋亡相关蛋白survivin及caspase3的表达与膀胱移行细胞癌发生及发展的关系。方法应用SP免疫组织化学法检测69例膀胱移行细胞癌石蜡切片,应用免疫印迹法（Western blotting）检测33例膀胱移行细胞癌新鲜组织中survivin和caspase3表达的情况,结合临床资料进行分析。结果免疫组化结果显示,survivin在膀胱移行细胞癌标本中的表达阳性率为88．4％（61／69）,而正常对照组均呈阴性;caspase3在膀胱移行细胞癌标本中的表达阳性率为59．4％（41／69）,但是与对照组相比无明显差异。Western blotting结果显示,93．9％（31／33）的肿瘤组织可见survivin蛋白表达,而对照组全部阴性表达;81．8％（27／33）的肿瘤标本可见caspase3蛋白表达,对照组中阳性表达率为80％（8／10）,实验组与对照组间无明显差异。在Ⅲ级膀胱移行细胞癌中survivin的表达强度较Ⅰ级为高,二者之间差异有显著性（P〈0．05）。survivin和caspase3的表达与肿瘤的临床分期无关（P〉0．05）,而且survivin的表达与easpase3的表达之间也没有相关性。结论survivin蛋白在膀胱移行细胞癌中特异性表达,其表达的上调可能提示肿瘤分化不良。Caspase3蛋白的表达情况与膀胱移行细胞癌关系不密切。     

醛酮还原酶1C2和组织蛋白酶D在膀胱移行细胞癌中的超表达及意义

目的：探讨醛酮还原酶1C2（AKR1C2）和组织蛋白酶D（cathepsinD）在膀胱移行细胞癌中的表达及其与膀胱癌病理分级、临床分期的关系。方法：应用免疫组织化学的方法检测AKR1C2和cathepsinD在40例膀胱癌组织和5例正常膀胱组织中的表达,并对比两者表达相关性。结果：40例膀胱癌中AKR1C2阳性表达率为80％,cathepsinD阳性表达率为90%,cathepsinD蛋白表达与膀胱癌病理分级、临床分期呈正相关（r=0．308）．AKR1C2蛋白表达在不同膀胱癌病理分级中差异有统计学意义（P〈0．05）。AKR1C2蛋白在不同临床分期之间表达差异无统计学意义。结论：结论：AKR1C2和cathepsinD表达特征可以作为膀胱移行细胞癌的诊断和判断预后的参考指标。     

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.