口服谷氨酰胺对化疗患者肠屏障功能的保护作用

目的观察谷氨酰胺对胃肠肿瘤术后化疗患者肠黏膜的保护作用。方法将胃肠道肿瘤手术后准备行化疗的39例患者分成观察组(22例)和对照组(17例),化疗方案为氟尿嘧啶(5-FU)加四氢叶酸(CF),连续5d。观察组化疗同时口服谷氨酰胺颗粒30g/d,分3次服,连续7d;对照组仅化疗。检测两组患者化疗前后血浆中谷氨酰胺浓度和尿中乳果糖/甘露醇(L/M)比值。结果观察组化疗后血浆中谷氨酰胺浓度为(594.44±81.26)μmol/L,较对照组的(535.42±53.75)μmol/L明显增高(P<0.01);尿中L/M比值治疗组(0.0321±0.0052)较对照组(0.0453±0.007)明显降低(P<0.01)。结论口服谷氨酰胺颗粒能够提高胃肠肿瘤术后化疗患者血谷氨酰胺浓度,减轻化疗后肠黏膜损伤程度,维护肠黏膜屏障功能。     

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本文研究化疗后大鼠补充含有谷氨酰胺和生长激素的肠外营养时，血浆和小肠中游离氨基酸的变化，探讨谷氨酰胺和生长激素对氨基酸代谢的影响及其协同作用。     

丙氨酰-谷氨酰胺双肽对肿瘤术后患者热休克蛋白70及肿瘤坏死因子的影响

目的 观察丙氨酰-谷氨酰胺双肽对肿瘤手术患者热休克蛋白、炎症反应及免疫状态的影响。方法 接受胸、腹部肿瘤切除手术患者116例进入研究，采用双盲设计，研究组58例接受丙氨酰-谷氨酰胺双肽补充的全胃肠外营养，对照组58例接受一般全胃肠外营养。7d后观察热休克蛋白（HSP）-70、肿瘤坏死因子（TNF）-α及CIM／CD8变化。结果 两组患者研究期间均未出现死亡及过敏等副反应，丙氨酰-谷氨酰胺组7d后TNF—α明显降低，CIM／CD8比率明显增多，HSP-70表达明显增高，差异有统计学意义（P〈0．05）；而对照组7d前后无明显变化。结论 肿瘤手术患者术后使用丙氨酰-谷氨酰胺能增加HSP-70表达，减轻患者炎症反应，并改善患者免疫功能状态，对患者恢复有益。     

谷氨酰胺联合早期肠内营养干预对胃癌术后疲劳综合症的研究

目的:探讨谷氨酰胺联合早期肠内营养对胃癌术后疲劳综合征的影响.方法:将60例胃癌患者随机分为肠内营养组,(EN n=30),肠内营养联合谷氨酰胺组( SE n=30),两组术后第1-5天均给予等氮,等热量的营养支持,SE组同时肠内给予谷氨酰胺颗粒注入,观察术后恢复情况,血浆白蛋白,术后疲劳综合评分各项指数的变化.结果:与EN组相比,SE 组术后住院时间明显短于EN组,两者比价有显著差异(P＜0.05)两组患者术前血浆白蛋白水平相似,在术后第5天SE组血浆白蛋白水平明显高于EN组(P＜0.05),术后累计疲劳均低于EN组(P＜0.05).结论:胃癌病人术后早期联合谷氨酰胺肠内营养比常规肠内营养更有利于改善机体的营养状态,减轻术后疲劳程度,加快术后康复.     

谷氨酰胺与肿瘤免疫、化学治疗、放射治疗(文献综述)

谷氨酰胺是机体内含量最丰富的氨基酸 ,在荷瘤机体常出现谷氨酰胺的缺乏。本文拟对谷氨酰胺在荷瘤机体中的代谢及在肿瘤免疫、化学治疗、放射治疗中的应用新的进展作一综述。     

谷氨酰胺与肿瘤免疫、化学治疗、放射治疗（文献综述）

谷氨酰胺是机体内含量最丰富的氨基酸，在荷瘤机体常出现谷氨酰胺的缺乏。本文拟对谷氨酰胺在荷瘤机体中的代谢及在肿瘤免疫、化学治疗、放射治疗中的应用新的进展作一综述。     

特殊营养素在外科患者中的应用

某些特殊营养素如谷氨酰胺、精氨酸、ω-3脂肪酸等具有治疗和调节机体代谢与免疫功能作用,可降低手术患者感染性并发症发生率,缩短住院时间.本文介绍药理营养或免疫营养概念以及其在胃肠道手术患者中的应用.     

高支链氨基酸在胃肠肿瘤术后患者营养支持治疗中的疗效

胃肠肿瘤患者术后短时间内无法进食,必须通过肠外或肠内途径改善机体营养状况以促进机体恢复。已有研究表明,支链氨基酸（branch chain amino acid,BCAA）对于手术创伤后的患者能抑制肌肉蛋白分解、促进肝脏蛋白合成和纠正负氮平衡,具有明显的节氮效应［1］。本研究通过比较胃肠肿瘤术后患者予以富含BCAA的高浓度复方氨基酸注射液和普通复方氨基酸注射液的营养支持效果,进一步评价富含BCAA的高浓度复方氨基酸注射液的临床疗效。     

免疫营养在胃肠道恶性肿瘤围手术期中的应用

胃肠道恶性肿瘤发病率较高, 且有40%～80%的胃肠道肿瘤患者存在营养不良, 肿瘤疾病本身的代谢机制及以手术为主的治疗方式导致围手术期应激反应可进一步加重营养不良。因此, 对有营养风险或营养不良的围手术期肿瘤患者应常规进行营养支持。长期以来, 以谷氨酰胺、ω-3脂肪酸、精氨酸及核苷酸等为主的免疫营养素在围手术期肿瘤患者中的治疗备受关注。围手术期免疫营养治疗不仅可以改善营养缺乏, 纠正营养不良;还能维持机体免疫功能和减轻炎症反应;以及维护肠屏障完整性, 减少术后并发症发生率和缩短术后住院时间等。然而, 近年来随着免疫营养在临床上的广泛应用与深入研究, 其在胃肠道恶性肿瘤围手术期的应用仍存在争议。笔者就胃肠道恶性肿瘤患者围手术期免疫营养素的药理机制与临床应用、免疫营养素围手术期联合应用、免疫营养应用时机等方面进行综述, 为其临床应用提供依据。     

丙氨酰-谷氨酰胺双肽对急性胰腺炎的治疗分析

目的评价丙氨酰-谷氨酰胺双肽对急性胰腺炎患者肠道损伤的治疗效果。方法采用随机双盲对照法,将220例受试患者随机分为治疗组和对照组。治疗组静脉滴注丙氨酰-谷氨酰胺双肽,200mL/d。对照组静滴200mL生理盐水,共7d。观察血浆谷氨酰胺浓度、肠黏膜损伤程度、血浆蛋白水平及免疫功能指标。结果治疗组患者血浆谷氨酰胺含量明显高于对照组（P〈0.05）;肠黏膜损伤程度明显低于对照组（P〈0.01）;血浆蛋白水平及免疫功能指标明显高于对照组。结论丙氨酰-谷氨酰胺双肽经静脉输入后能显著提高血浆谷氨酰胺浓度,明显减轻急性胰腺炎患者肠黏膜损伤程度,维护肠黏膜屏障功能,增强机体免疫功能,减少机体氮的丢失,提高治疗效果。     

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.