正常(牙合)者下颌运动的肌电活动研究

目的研究正常(牙合)者在姿势位及下颌不同运动中,双侧颞肌前束(TA),后束(TP),嚼肌(MM),二腹肌前腹(DA)的肌电活动情况.方法采用美国BioEMG Ⅱ八道表面肌电仪和瑞士Kistler双极表面电极,同步记录30例正常牙合者上述诸肌的肌电变化.结果①姿势位:TA,TP,MM,DA均有轻微的肌电活动,其中TP的活动比较明显,起主要作用;②正中牙合位最大紧咬:TA,TP,MM均有强烈的肌电活动,其肌电压值达到最高峰,TA肌电活动最大,其次为MM,再次为TP;③前伸运动:MM,DA的肌电活动大于TA,TP;④后退运动:DA肌电活动最明显,其次为TP; ⑤左右侧方运动:肌电活动主要表现在同侧TA和TP,对侧MM和左右侧DA.结论 TA是重要的升颌肌;TP是维持姿势位、下颌后退和侧方运动的主要肌肉;MM为下颌紧咬产生咬(牙合)力,以及下颌前伸的主要肌肉;DA参加下颌的各种运动,起调节作用.     

正常[牙合]者下颌运动的肌电活动研究

目的 研究正常[牙合]者在姿势位及下颌不同运动中，双侧颞肌前束（TA），后束（TP），嚼肌（MM），二腹肌前腹（DA）的肌电活动情况。方法 采用美国BioEMGⅡ八道表面肌电仪和瑞士Kistler双极表面电极，同步记录30例正常[牙合]者上述诸肌的肌电变化。结果 ①姿势位：TA，TP，MM，DA均有轻微的肌电活动，其中TP的活动比较明显，起主要作用；②正中[牙合]位最大紧咬：TA，TP，MM均有强烈的肌电活动，其肌电压值达到最高峰，TA肌电活动最大，其次为MM，再次为TP；③前伸运动：MM，DA的肌电活动大于TA，TP；④后退运动：DA肌电活动最明显，其次为TP；⑤左右侧方运动：肌电活动主要表现在同侧TA和TP，对侧MM和左右侧DA。结论 TA是重要的升颌肌；TP是维持姿势位、下颌后退和侧方运动的主要肌肉；MM为下颌紧咬产生咬胎力，以及下颌前伸的主要肌肉；DA参加下颌的各种运动，起调节作用。     

改良固定反式TBA联合前牵矫治AngleIII类前牙反的肌电研究

目的:应用改良固定反式双阻板矫治器(Twin-blockappliance,TBA)联合前牵治疗AngleIII类轻、中度骨性前牙反牙合,进行肌电研究,探讨在矫治过程中咀嚼肌功能活动的变化规律,以期从咀嚼肌适应性改建来探讨其作用机制。方法:调查颞肌前束(TA)、咬肌(MM)、二腹肌前腹(DA)治疗前、中、后肌电活动变化情况。结果:矫治后姿势位TA、DA、MM肌电值(MCV)明显下降;反牙合时下颌前伸位TA及DA存在异常的肌电活动,在治疗后均明显降低;治疗前后退位MM、TA及DA肌电活动与对照组相比均较大,具有显著性差异,治疗结束后明显下降;反牙合解除后紧咬及双侧咀嚼运动MM、TA及DA肌电水平明显增加。结论:反式TBA联合前牵全天作用可引起神经肌肉的适应性改建。     

前伸头位对咀嚼肌功能活动时的肌电影响

目的：研究前伸头位对牙尖交错位自主用力紧咬和吞咽两功能活动时咀嚼肌肌电活动的影响。方法：以30名健康正常青年女性受试者为研究对象,应用BioEMGII型表面肌电测量仪,测量正常人群分别在自然头位和最大前伸头位情况下,牙尖交错自主用力紧咬以及吞咽时颞肌前束（TA）、咬肌（MM）、胸锁乳突肌（SCM）、二腹肌前腹（DA）的肌电幅值,并对结果进行统计学分析。结果：最大前伸头位吞咽时TA、MM、SCM、DA的肌电幅值以及最大前伸头位牙尖交错位自主用力紧咬时MM和DA的肌电幅值与自然头位时相比增高且具有统计学意义（P〈0.05）;最大前伸头位牙尖交错位自主用力紧咬时TA以及SCM的平均肌电幅值高于自然头位时的肌电幅值,但差别没有统计学意义（P〉0.05）。结论：吞咽活动时各咀嚼肌对最大前伸头位有着明显的反应,牙尖交错位紧咬时MM和DA对前伸头位反应明显,最大前伸头位时各咀嚼肌肌紧张度增加,肌电活动增强。     

改良固定反式TBA联合前牵矫治AngleⅢ类前牙反(牙合)的肌电研究

目的：应用改良固定反式双阻板矫治器（Twin-block appliance，TBA）联合前牵治疗AngleⅢ类轻．中度骨性前牙反[牙合]，进行肌电研究，探讨在矫治过程中咀嚼肌功能活动的变化规律，以期从咀嚼肌适应性改建来探讨其作用机制。方法：调查颞肌前束（TA）、咬肌（MM）、二腹肌前腹（DA）治疗前、中、后肌电活动变化情况。结果：矫治后姿势位TA．DA、MM肌电值（MCV）明显下降；反[牙合]时下颌前伸位TA及DA存在异常的肌电活动，在治疗后均明显降低；治疗前后退位MM、TA及DA肌电活动与对照组相比均较大，具有显著性差异，治疗结束后明显下降；反[牙合]解除后紧咬及双侧咀嚼运动MM、TA及DA肌电水平明显增加。结论：反式TBA联合前牵全天作用可引起神经肌肉的适应性改建。     

Ⅲ类错患者的咬合与肌电研究

目的:探讨Ⅲ类错畸形对咬合与肌电的影响。方法:使用T-SCANⅢ与肌电仪对16名Ⅲ类错畸形患者进行检测,其中男7例,女9例,平均年龄(15.59±2.51)岁,采集患者在姿势位、牙尖交错位(ICP)最大紧咬、前伸切对切最大紧咬时的咬合与肌电情况。结果:Ⅲ类患者在姿势位时的颞肌、咬肌肌电高于对照组(P0.05),切对切最大紧咬时低于对照组(P0.05),ICP最大紧咬时与对照组无统计学差异(P0.05)。结论:Ⅲ类错畸形会导致患者咀嚼肌肌电发生异常。     

不同垂直颅面结构年轻女性嚼肌超声厚度及肌电活动的相关性研究

目的:探讨不同垂直颅面结构的嚼肌超声厚度和肌电活动之间的关系.方法:选取30名女大学生(高角14例、低角16例),应用B超测量姿势位和紧咬位的嚼肌厚度及表面电极测量姿势位和紧咬位的嚼肌肌电活动.结果:低角组浅层嚼肌厚度在姿势位和紧咬位均大于高角组,具有明显统计学差异;在姿势位低角组与高角组之间嚼肌肌电活动差异无统计学意义；在最大紧咬位低角组的肌电活动显著大于高角组的肌电活动,差异有统计学意义;姿势位和紧咬位时嚼肌厚度与最大紧咬位肌电活动均呈正相关.结论:不同垂直骨面型的嚼肌形态功能不同；低角骨面型的嚼肌超声厚度与肌电活动均大于高角组.     

成人骨性反(牙合)的咀嚼肌肌电特征

目的:本研究通过对成人骨性反牙合患者主要咀嚼肌肌电检查分析,揭示成人骨性反牙合畸形对咀嚼肌功能的影响。方法:20名患者均为需正畸与正颌手术联合治疗的成人骨性反牙合患者。利用肌电图仪测试咬肌、颞肌前束、二腹肌前腹在功能活动中肌电变化。结果:与对照组相比,咬肌、颞肌前束和二腹肌前腹的肌电,除个别功能位外,与对照组均有显著不同,其中咬肌的肌电变化最明显。咀嚼肌在姿势位、前伸位、后退位、张口位、闭口位的肌电值增大;双侧咀嚼时,咀嚼肌的肌电是下降的。结论:骨性反牙合患者的咀嚼肌肌肉长期处于紧张状态,咀嚼肌肌电异常,患者咀嚼功能低下。     

成人骨性反he的咀嚼肌肌电特征

目的：本研究通过对成人骨性反he患者主要咀嚼肌肌电检查分析，揭示成人骨性反he畸形对咀嚼肌功能的影响。方法：20名患者均为需正畸与正颌手术联合治疗的成人骨性反he患者。利用肌电图仪测试咬肌、颞肌前束、二腹肌前腹在功能活动中肌电变化。结果：与对照组相比，咬肌、颞肌前束和二腹肌前腹的肌电，除个别功能位外，与对照组均有显著不同，其中咬肌的肌电变化最明显。咀嚼肌在姿势位、前伸位、后退位、张口位、闭口位的肌电值增大；双侧咀嚼时，咀嚼肌的肌电是下降的。结论：骨性反he患者的咀嚼肌肌肉长期处于紧张状态，咀嚼肌肌电异常，患者咀嚼功能低下。     

下颌偏突颌畸形患者双侧下颌骨升支矢状劈开术前后咀嚼肌功能变化探究

目的:探究下颌偏突颌畸形患者双侧下颌骨升支矢状劈开术(BSSRO)前后咀嚼肌功能变化。方法:选取2016年6月-2018年6月笔者医院收治的31例下颌偏突颌畸形患者为观察组,另选取30例年龄相仿的正常志愿者为对照组。测定两组自由咀嚼状态下的半分钟咀嚼效能、吞咽反射前咀嚼效能。采用OXFORD双通道肌电诱发仪采集两组紧咬位、大张口运动的MML、MMR、TAL、TAR肌电值;计算相应部位的咀嚼肌活动量指数(AcI)。结果:术前,观察组患者的半分钟及吞咽反射前咀嚼效能,紧咬位、大张口运动时的MML、MMR、TAL、TAR及AcI指标均低于对照组,差异有统计学意义(P<0.05);术后3个月,观察组患者的咀嚼效能指标及各功能运动中的MML、MMR、TAL、TAR肌电值均明显小于对照组及术前(P<0.05),各功能运动中AcI指标明显大于术前(P<0.05);术后1年,观察组患者的咀嚼效能指标及各功能运动中的MML、MMR、TAL、TAR肌电值均明显高于术后3个月(P<0.05),但部分指标仍与对照组无差异(P>0.05)。结论:下颌偏突颌畸形患者术前的咀嚼肌功能弱于健康人群,行BSSRO后咀嚼肌功能得到了一定程度的改善。     

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.     

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.     

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.