肿瘤坏死因子在肠缺血所致多脏器损伤中的作用

应用大鼠肠系膜上动脉夹闭模型，对不死因子（ＴＮＦ）在肠缺血所致多脏器损伤中的作用进行了探讨。结果发现，肠缺血再灌注初期循环ＴＮＦ水平即显著升高，其动态变化与门脉系统内毒素血症密切相关；预防性给予ＴＮＦＭｃＡｂ治疗则可有效地减轻机体的全身性损害。提示：严重损伤早期体内ＴＮＦ的过度产生、释放，对宿主肝、肾及肺等器官有明显影响，这可能是导致脓毒症、多系统器官功能衰竭等并发症的重要原因之一。     

参附注射液对缺血再灌注家兔多脏器损伤的治疗作用

目的：观察参附注射液（ＳＦ）对缺血再灌注家兔多脏器细胞损伤的保护作用。方法：家兔１８只，采用失血性休克模型，随机分为三组，检测多脏器组织中ＳＯＤ、ＭＤＡ、ＴＮＦ含量及血浆酸性磷酸酶（ＡＣＰ）、镁浓度，小肠组织作透射电镜观察。结果：再灌９０分钟后ＳＦ治疗组肝、肾、肺、肠组织中的ＭＤＡ和ＴＮＦ水平低于对照组，ＳＯＤ水平则高于对照组，血ＡＣＰ、Ｍｇ２＋浓度治疗组低于对照组。电镜观察，肠粘膜上皮细胞损伤ＳＦ组不明显。结论：ＳＦ对兔缺血再灌注多脏器细胞的损伤有保护作用。     

肠缺血再灌注损伤后内毒素增敏作用及其机制的初步探讨

目的 探讨肠缺血再灌注损伤（Ｉ／Ｒ）对内毒素的增敏作用及其机制。方法 大鼠肠系膜上动脉阻断４５ｍｉｎ后松夹进行再灌注，静脉注射低剂量内毒素（ＬＰＳ，１．５ｍｇ／ｋｇ）。观察动物多脏器功能指标及体外诱生肿瘤坏死因子（ＴＮＦ）的改变。结果 Ｉ／Ｒ＋ＬＰＳ组显著加重全身血流动力学异常改变和肝、肺、肠等器官功能损害（Ｐ〈０．０１）。而单纯ＬＰＳ组或Ｉ／Ｒ组上述指标改变较轻或无明显异常。体外试验显示，当ＬＰ     

抗TNFα单抗对肠缺血/再灌注大鼠血液动力学的影响

目的：观察应用抗肿瘤坏死因子－α（ＴＮＦα）单导重度肠缺血／再灌注损伤时动物血液动力学的影响及其机理。方法：大鼠肠系膜上动脉阻断７５分钟后再灌注６小时，分别静脉给予抗ＴＮＦα单抗或白蛋白。结果：使用抗ＴＮＦα单抗可减轻缺血／再灌注所致血压和心脏指数下降，每搏输出量维持于伤前范围。防治组７２小时存活率显著高于对照组。抗ＴＮＦα单抗可有效中和循环中ＴＮＦα，并抑制心肌组织ＴＮＦｍＲＮＡ的表达。结论：抗     

己酮可可碱对肠缺血再灌注致多器官损伤的保护作用

研究多形核中性粒细胞在多器官损伤中的作用及ＰＭＮ活化的抑制剂己酮可可碱对器官损伤的保护作用。方法；采用大鼠肠缺血再灌注致多器官损伤的损伤的模型。结果；肠缺血再灌注可导致肠及远端器官肝，肺中ＰＭＮ聚集明显增加，并伴有这些器官的损伤，己酮可可碱可明显抑制肠缺血再灌注引起的ＰＭＮ聚集，同时肠，肝，肺组织损伤的指标明显改善。     

肿瘤坏死因子在肠缺血所致多脏器损伤中的作用

应用大鼠肠系膜上动脉夹闭模型,对肿瘤坏死因子(TNF)在肠缺血所致多脏器损伤中的作用进行了探讨。结果发现,肠缺血再灌注初期循环 TNF 水平即显著升高,其动态变化与门脉系统内毒素血症密切相关;预防性给予 TNF-McAb 治疗则可有效地减轻机体的全身性损害。提示:严重损伤早期体内 TNF 的过度产生、释放,对宿主肝、肾及肺等器官功能有明显影响,这可能是导致脓毒症、多系统器官功能衰竭等并发症的重要原因之一。     

肠缺血与多器官功能障碍

肠缺血、缺血再灌注损伤及内毒素等激发的炎性瀑布反应在多器官功能障碍发生机制中占有重要地位。对肠缺血及缺血再灌注的病理生理、肠缺血的早期监测及其损伤的防治作一综述。     

肠缺血与多器官功能障碍

肠缺血、缺血再灌注损伤及内毒素等激发的炎性瀑布反应在多器官功能障碍发生机制中占有重要地位。对肠缺血及缺血再灌注的病理生理、肠缺血的早期监测及其损伤的防治作一综述。     

肿瘤坏死因子—α单抗对烫伤大鼠组织脂多糖结合蛋白mRNA表达 …

探讨肿瘤坏死因子－α单抗治疗对烫伤后组织ＴＮＦ－α及脂多糖结合蛋白ｍＲＮＡ表达、不同器官功能改变的影响。方法采用大鼠３５％体表面积Ⅲ度烫伤模型,检测伤后肺,肝,肠肾等组织ＴＮＦ－α及ＬＢＰｍＲＮＡ水平。结果烫伤后肺,肝,肠,肾等组织ＴＮＦ－α及ＬＢＰＭｒｎａ表达前水平均有显著升高,约为正常对照地１．７－２．５倍。     

喂服双歧杆菌制剂对烧伤大鼠肿瘤坏死因子变化的影响

肿瘤坏死因子 (ＴＮＦα)是由激活的单核巨噬细胞系统产生的一种内源性无种属特异性的细胞调节因子 ,它一方面参与机体的免疫防御机能 ,是机体细胞免疫反应释放的细胞因子之一 ,另一方面又参与介导休克、炎症反应和组织器官损伤等病理生理过程。在血管内皮细胞和肝、肾、肠、肌肉及皮肤等正常器官的多种细胞表面都含有ＴＮＦα高亲和力受体 ,它对组织细胞和血管内皮细胞有直接毒性作用 ,可造成组织细胞的结构破坏和功能障碍。为此 ,本实验观察了烧伤大鼠喂服双歧杆菌后ＴＮＦα的变化情况。材　料　和　方　法1.动物模型及分组 :Ｗｉｓｔａ…     

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.