人参皂甙Rg3联合小剂量化疗抑制小鼠S-180肉瘤血管生成的作用

目的：观察人参皂甙Rg3联合持续小剂量环磷酰胺（CTX）对小鼠S-180肉瘤肿瘤血管生成的影响、抑瘤作用及毒副反应。方法：建立S-180肉瘤小鼠移植性肿瘤模型，60只小鼠随机分为4组，分别为人参皂甙Rg3组（5mg／kg）、CTX组（5mg／kg）、联合治疗组（人参皂甙Rg3和CTX的联合治疗）及模型对照组。治疗结束后测定肿瘤组织重量、肿瘤微血管密度（MVD）和血管内皮生长因子（vEGF）表达情况。结果：人参皂甙Rg3组、CTX组和联合治疗组小鼠移植瘤的瘤重较对照组降低（P〈0．05），肿瘤抑制率分别为36．12％、49．43％、71．10％，MVD及VEGF的表达较对照组均下降（P〈0．05），其中联合治疗组更明显（P〈0．05）。联合治疗组小鼠毒副作用较轻，生存质量较好。结论：小剂量CTX与人参皂甙Rg3联合应用显示出明显的抗血管生成协同作用，抑瘤效果显著，且毒副反应小。     

蟾酥注射液对小鼠S180和人结肠癌HT-29裸鼠移植性肿瘤的影响

目的研究蟾酥注射液对小鼠移植性肿瘤 S180和人结肠癌 HT-29裸鼠移植性肿瘤的抑制作用.方法分别用小鼠 S180和人结肠癌 HT-29裸鼠两种荷瘤小鼠模型,观察药物对上述肿瘤的抑瘤作用,并镜下观察后者细胞凋亡情况.结果与荷瘤阴性对照组比较,蟾酥注射液各剂量组对小鼠 S180抑瘤率( IR)为 19.1%～38.2%(P<0.05),呈量效关系;而对人结肠癌 HT-29裸鼠移植性肿瘤的 IR为 9.5%～15.8%(P>0.05),也呈量效关系,但差异均未见统计学意义;环磷酰胺则能显著抑制小鼠 S180和 HT-29细胞裸鼠移植性肿瘤的生长( IR分别为70.7%和 67.1%, P<0.01),镜检可见其有显著促进肿瘤细胞凋亡作用;未发现实验药物出现明显的毒副作用.结论该实验所用的蟾酥注射液,对小鼠 S180有抑制作用,而对人结肠癌 HT-29裸鼠移植性肿瘤,则作用不明显,表明不同类型的肿瘤对其敏感性不同.     

肿瘤浸润淋巴细胞与白介素2联用抑制Lewis肺癌生长和转移的研究

目的 研究Lewis肺癌(LLC）肿瘤浸润淋巴细胞(TIL）对荷瘤鼠体内的抗瘤作用。方法 从接种于C57BL/6小鼠体内的LLC瘤体中分离提取TIL，经1000u／ml白细胞介素-2(IL-2)的完全培养基中培养后，与LLC细胞以10：1接种于C57BL／6小鼠腋下，每口1000u IL-2瘤内注射，于接种后第18天处死小鼠。结果 经TIL和IL-2处理的小鼠肿瘤重量明显低于其它各组(P＜0．001)，且肺转移发生率也较其它各组低（P＜0.001）。结论 肿瘤浸润淋巴细胞与IL-2联用可明显抑制LLC的生长和转移。     

p16与细胞因子基因联合基因疗法对荷瘤小鼠免疫功能的影响

目的 探讨瘤体内直接注射途径的ｐ１６抑癌基因疗法与细胞因子（ＧＭ－ＣＳＦ）基因疗法联合应用对荷瘤肾癌小鼠免疫功能的影响。方法 建立皮下荷瘤肾癌小鼠模型。于接种种瘤细胞３ｄ后将荷瘤小鼠随机分为５组,分别给予不同的治疗,检测每组小鼠的免疫功能,观察每组小鼠的存活期,并行肿瘤病理学分析。结果 与其它４组相比,ｐ１６和ＧＭ－ＣＳＦ联合治疗组小鼠机体免疫功能显著增强（Ｐ〈０．０１）,存活时间明显延长（Ｐ〈０．０５）。结论 ｐ１６与ＧＭ－ＣＳＦ联合基因疗法的应用可增强小鼠抗肿瘤免疫反应,并抑制肿瘤的生长。     

瘤体内注射无水乙醇对小鼠移植性肿瘤治疗作用的研究

通过动物实验研究瘤体内注射无水乙醇对小鼠移植性肿瘤的治疗作用机理。结果表明：瘤体内注射无水乙醇治疗小鼠移植性肿瘤是有效的，它可以直接杀死肿瘤细胞，使肿瘤体积缩小甚至消失，肿瘤抑制率增加（ＨｅｐＡ７６．１７％，Ｓ１８０、６１．１８％、Ｅｈｒｌｉｃｈ氏癌８１．６０％）及荷瘤小鼠的生命延长率增加，同时对全身免疫器官及末梢血白细胞、血红蛋白含量无明显影响，不矢为一种值得试用的抗肿瘤疗法。对瘤体内注射无水乙醇治疗肿瘤的机理进行了简要讨论。     

老鹳草提取物对Lewis结肠癌瘤株转染的Livin基因影响的实验研究

为研究老鹳草提取物对Lewis结肠癌瘤株转染的C57BL／6小鼠Livin基因表达的影响,探讨其抗转移机制,本研究成功建立了Lewis结肠癌瘤株小鼠皮下移植瘤模型,并将48只小鼠随机分为空白对照组、老鹳草提取物组和羟基喜树碱组,观察各组移植瘤体生长情况,免疫荧光法检测移植瘤组织中Livin基因表达情况。结果显示,与空白对照组相比,老鹳草提取物组和羟基喜树碱组移植瘤体积均缩小（P〈0．01）,移植瘤组织中Livin基因表达均降低（P〈0．01）;但老鹳草提取物组比羟基喜树碱组移植瘤体积缩小及移植瘤组织中Livin基因表达降低更明显（P〈0．01）。结果表明,老鹳草提取物的抗Lewis结肠癌转移机制可能与降低Livin基因的表达有关。     

竹叶多糖对小鼠移植瘤的抑制作用

研究了竹叶多糖对小鼠移植瘤的抑制作用。实验结果表明，竹叶多糖对动物移植性Ｓ１８０肿瘤有抑制作用，抑制率可达５０％．５０％～７０％醇沉组分抑瘤活性最大，且能显著提高小鼠腹腔巨噬细胞的吞噬能力。     

血清胰岛素样生长因子-1对癌性恶病质小鼠营养状况的影响

目的探讨血清中胰岛素样生长因子-1（IGF-1）水平与癌性恶病质机体营养状况的关系。方法用小鼠结肠腺癌CT-26细胞接种于肝特异性IGF-1基因缺失（LID）鼠及对照组小鼠皮下建立癌性恶病质模型，LID鼠和对照鼠各30只。肿瘤种植后，监测2组小鼠体重、肿瘤重量及去瘤体重，并监测肿瘤种植后第14、18及22d血清IGF-1、TNF-α、IL-6、血糖、甘油三酯和白蛋白水平。结果肿瘤种植后，各时间点LID组IGF-1水平均显著低于对照组（P〈0．05）。随时间延长，2组荷瘤鼠TNF-α、IL-6、血糖及甘油三酯水平均逐渐升高（P〈0．05），去瘤体重和白蛋白水平均逐渐下降（P〈0．05）。在3个实验观察时点，与对照组荷瘤鼠相比，LID组荷瘤鼠血清TNF-α、IL-6、甘油三酯及血糖水平均较高（P〈0．05）。在第18及22d，LID组荷瘤鼠去瘤体重较对照组荷瘤鼠轻（P〈0．05），摄食量低于对照组荷瘤鼠（P〈0．05）。结论在癌性恶病质机体中，相对于低水平IGF-1而言，正常水平血清IGF-1对应着较低水平的恶病质相关细胞因子和较好的机体营养状态，这为癌性恶病质的治疗提供了新的思路。     

马氏钳蝎毒抗癌多肽与5—Fu对小鼠肝癌的联合治疗作用

目的 探讨马氏钳蝎毒抗癌多肽（ＡＰＢＭＶ）单独及其与５－Ｆｕ联合对小鼠肝癌抑瘤作用。方法 采用小鼠腹水型肝癌Ｈ２２的荷瘤模型观察了ＡＰＢＭＶ的体内抑瘤作用和对５－Ｆｕ抑癌作用的影响。结果 ＡＰＢＭＶ在所用剂量「（０．０３－０．０６）ｍｇ／（ｋｇ．ｄ），用１０ｄ」范围内对Ｈ２２荷瘤小鼠无显著的抑瘤作用。     

磁流体热疗对荷Lewis肺癌小鼠肿瘤细胞凋亡和周期的影响

目的探讨磁流体热疗对荷Lewis肺癌小鼠肿瘤细胞的凋亡和周期的影响。方法接种Lewis肺癌细胞悬液于C57BL／6小鼠的皮下，等肿瘤长至直径约为（0．8±0．1）cm时，随机分为4组：对照组、磁场组、磁流体组、实验组。加温治疗后48h，眼球取血，检测血中白细胞的变化，切取肿瘤标本，流式细胞仪检测细胞凋亡率和周期的变化。结果热疗后4组血中自细胞没有明显的变化（F=0．62，P=0．613）；肿瘤细胞凋亡率实验组为（63．55±8．39）％，对照组、磁场组、磁流体组分别为（28．43±6．29）％，（32．75±5．07）％，（32．42±6．15）％，实验组肿瘤细胞凋亡率明显高于其他3组（q=11．925，P〈0．05；g=10．458。P〈0．05；g=10．570，P〈0．05）；实验组细胞周期出现明显G1／G0期阻滞为（68．13±5．73）％显著高于对照组（47．95±9．98）％（q=5．501，P〈0．05），磁场组（49．23±6．62）％（q=5．152，P〈0．05），磁流体组（52．28±9．64）％（q=4．320，P〈0．05）。结论磁流体热疗可明显提高Lewis肺癌细胞的凋亡率，抑制Lewis肺癌细胞G1期向S期的进程。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.