低温对兔离体多系统动脉舒张功能的影响

目的 探讨低温对兔肺动脉、肾动脉、颈动脉内皮依赖性舒张与非内皮依赖性舒张的影响。方法 选24只白兔，每8只兔取一种血管环，每一实验组血管环选自同一只白兔。8只血管环为一实验组，随机分为对照组（37℃）、实验组1（30℃）、实验组2（24℃）、实验组3（16℃）。建立不同低温乙酰胆碱、硝酸甘油浓度依赖性曲线。测定不同低温对乙酰胆碱及硝酸甘油引起动脉内皮依赖性舒张及非内皮依赖性舒张的影响。结果 各低温组与常温组及前一低温组之间相比，低温抑制肺动脉、肾动脉、颈动脉内皮依赖性佶张与非内皮依赖性舒张（P＜0．001）。结论 低温抑制动脉内皮依赖性舒张与非内皮依赖性舒张功能减弱，这对心脏手术后并发症的发生机制的深入理解有重要临床意义。     

程序化降温保存血管内皮功能的研究

目的：探讨程序化降温对体外大鼠血管内皮的影响。方法：对大鼠腹主动脉进行0．7℃／min（新鲜血管组和常规方法组）及1℃／min（试验组）程序化降温，低温保存3个月后对比观察血管内皮形态和功能变化。结果：试验组的平均收缩张力及非依赖性血管舒张均较常规组高（P〈0．05），但对于Ach引起的内皮依赖性血管舒张，两组差异不明显（P〉0．05）；光镜下试验组皿管内皮细胞较常规组完整。结论：改良的降温程序能够较好保持内皮的收缩功能以及非内皮依赖性舒张功能，但对内皮依赖性舒张功能效果欠佳。     

复方丹参滴丸对冠心病患者内皮细胞生长因子及内皮抑素的影响

目的观察冠心病患者使用复方丹参滴丸前后血管内皮生长因子及内皮抑素水平的变化。方法选择2009年6月-2011年6月笔者所在医院住院患者86例,随机分为观察组及对照组,观察组给予复方丹参滴丸,10粒／次,3次,d,连续用药8周。两组受试者均于用药前及用药8周后清晨抽取空腹静脉血检测VEGF及ES。结果在治疗前两组VEGF和ES差异无统计学意义（P〉0．05）;同对照组相比,观察组用药后VEGF水平明显降低,而ES升高（P〈0．05）;同用药前相比观察组用药后VEGF水平同样明显降低,ES升高（P〈0．05）。结论冠心病患者使用复方丹参滴丸可使VEGF水平降低,而ES水平升高。     

血液透析对肱动脉内皮功能影响的临床研究

目的：通过观察不同透析时间患者肱动脉内皮功能,评价血液透析对血管内皮的影响及其时间变化规律。方法：利用高频超声,测量血液透析患者（HD组）、尿毒症非透析患者（pre-HD组）和健康志愿者（正常组）的肱动脉收缩期、舒张期内径及反应性充血后内径,计算肱动脉的扩张系数（DC）、僵硬度（SD）和血流介导的内径扩张值（FMD）。结果：与正常组相比,HD组和pre-HD组肱动脉DC值、FMD值减小,SD值增大,差异有统计学意义（P〈0.01）;HD组透析12月患者和pre-HD组患者间各项指标差异无统计学意义（P〉0.05）;透析36月肱动脉DC值、FMD值显著小于透析12月（P〈0.01）,SD值显著大于透析12月（P〈0.01）;透析60月与透析36月相比各观察指标差异无统计学意义（P〉0.05）。结论：血液透析可以加重尿毒症患者内皮功能损伤,且这种作用与透析时间长短有一定关系。     

内皮素 - 1对离体动脉的收缩作用及舒张药物的对抗效应

目的　研究内皮素-1（Endothelin-1,ET-1）收缩血管的特性及显微血管外科常用舒张药物的对抗效应。方法　采用离体血管舒缩功能的实验技术比较ET-1与去甲肾上腺素（noradrenaline,NE）对离体动脉张力的影响,同时检测舒张药物对ET-1收缩血管的拮抗作用。结果　ET-1使离体大鼠颈总动脉环产生浓度依赖性的恒定收缩,ET-1与NE的半数有效浓度(medianeffectiveconcentration,EC     

普伐他汀治疗肾移植术后血脂异常的前瞻性研究

目的 探讨他汀类药物对肾移植术后血脂异常的疗效。方法 将27例肾移植术后高胆固醇血症患者（血浆胆固醇总量水平〉6．2mmol／L）作为普伐他汀组，患者每日口服普伐他汀10mg，每晚1次，疗程8周。另取健康男、女各15例作为对照组，对照组在8周内未服用任何药物。测定普伐他汀组治疗前、后及对照组的血清胆固醇总量（TC）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）、甘油三酯（TG）、血浆内皮素（ET）、一氧化氮（NO）的变化。采用高分辨血管外超声技术测定各组肱动脉血流介导的舒张功能及服用硝酸甘油介导的舒张功能。结果 普伐他汀组治疗前血浆ET含量显著高于对照组，NO含量则显著低于对照组；降脂治疗8周后，ET含量明显下降（P〈0．01），NO含量明显升高（P〈0．01），血TC、LDL-C、TG也较治疗前明显降低（P〈0．05）。普伐他汀组治疗前肱动脉血流介导的舒张功能低于对照组，治疗后较治疗前明显好转。结论 普伐他汀可有效治疗肾移植后血脂异常，并可显著改善血管内皮细胞功能。     

别嘌呤醇对慢性肾衰竭患者肾脏保护作用及机制

目的观察别嘌呤醇对慢性肾衰竭（CRF）患者肾功能的保护作用。方法将入选的86例CRF（除外尿酸性肾病）患者分成对照组和治疗组,对照组给予CRF常规非透析疗法治疗;治疗组则在对照组基础上加用别嘌呤醇治疗;观察4周。测定2组治疗前后患者的尿素氮（BUN）、血肌酐（SCr）、血尿酸、一氧化氮（NO）,内皮素1（ET-1）,血栓素B2（TXB2）、6-酮-前列腺素F1α（6-keto-PGF-1α）及超敏C反应蛋白（hs-CRP）。结果治疗组治疗后,BUN、SCr及血尿酸较同组治疗前显著降低（P〈0．05）,与对照组比较有统计学差异（P〈0．05）;ET-1和NO分别较同组治疗前降低和升高（P〈0．05）,TXB2和6-keto-PGF-1α分别较治疗前降低和升高（P〈0．05）,hs-CRP较同组治疗前下降（P〈0．05）,与对照组比较均有统计学差异（P〈0．05）。结论别嘌呤醇对CRF患者肾功能具有保护作用,其可能是通过抗微炎症状况和改善血管内皮功能的作用。     

血管内皮生长因子和内抑素在STZ大鼠肾脏中的表达及意义

目的：研究血管内皮生长因子（VEGF）和内抑素（ENS）在2型糖尿病大鼠肾脏中的表达状况、比值变化及与肾脏微血管病变的关系。方法：将Wister大鼠设正常对照组和模型组，使用STZ诱导形成2型糖尿大鼠肾病模型，分别于2、4、8、12周，采用RT-PCR的方法观察大鼠肾脏VEGF和ENSmRNA的表达，并观察其比值变化，同时采用免疫组化观察VEGF蛋白的表达变化。结果：（1）糖尿病组2周时肾脏中VEGFmRNA开始上调（P〈0．05），4、8、12周时较正常对照组明显上调（P〈0．01）。（2）糖尿病组2周时肾脏中ENSmRNA的表达开始上调（P〈0，05），8、12周时表达明显上调（P〈0．01）。（3）糖尿病组2周时肾脏的VEGFmRNA／ENSmRNA值未见变化（P〉0．05），4周时升高（P〈0．05），12周时明显升高（P〈0．01）。（4）免疫组化显示糖尿病肾病组2周时VEGF升高，12周时升高更明显。结论：VEGF和ENS同时参与了糖尿病肾病的血管生成调控，两者表达水平的失衡是其新生血管形成的关键。     

高脂血症对肱动脉内径达峰时间的影响

目的探讨高脂血症对肱动脉内径达峰时间的影响。方法选取到我院就诊、未曾治疗的40例高脂血症患者作为研究对象（高脂血症组）,另选对照组30名,应用在血管回声跟踪技术（eTRACKING）基础上实现的血流介导血管舒张（FMD）检测技术及FMD专用检测装置测量肱动脉内径达峰时间,并进行分析。结果高脂血症组肱动脉内径达峰时间为（70.70±6.99）s,对照组为（60.25±5.38）s,差异有统计学意义（P〈0.001）。结论高脂血症患者动脉内膜出现异常改变之前已出现内皮功能损伤,运用这种新的FMD检测技术测量肱动脉内径达峰时间,可作为判断早期血管功能受损的新指标。     

冷冻速率对猪主动脉冷冻保存效果的影响

目的比较不同冷冻速率对大口径猪动脉功能及内皮的影响.方法 16头乳猪切取胸主动脉,每根主动脉分3段,作为对照、-1℃/min冷冻和-5℃/min冷冻处理.分别测定内皮细胞死亡率和血管活性药物引起的收缩、舒张程度.结果 -5℃/min冷冻组内皮细胞死亡率明显高于-1℃/min冷冻组和对照组,P＜0.01.冷冻组由去甲肾上腺素引起的收缩张力值明显低于未冷冻对照组P＜0.01.-5℃/min组明显低于-1℃/min组,P＜0.01.冷冻组由乙酰胆碱引起的张力下降绝对值与对照组差异无显著性,P＞0.05;舒张程度与对照组有明显差异,P＜0.01.-5℃/min组舒张程度明显低于-1℃/min组,P＜0.01.内皮细胞死亡率与乙酰胆碱舒张作用呈负相关,P＜0.05.结论冷冻对猪主动脉的结构和功能造成损伤.慢速冷冻对内皮细胞破坏小,对血管平滑肌的收缩和内皮依赖性舒张的损害小.     

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.