聚丙烯酰胺水凝胶注入兔体后组织病理学与免疫组化的动态观察

目的动态观察聚丙烯酰胺水凝胶(奥美定)注入兔体后,对组织细胞形态学及Bcl-2、P53、HsP70、PCNA表达的影响。方法将24只新西兰白色家兔分为三组,注入奥美定5ml/kg的10只为Ⅰ组,注入奥美定10ml/kg的11只为Ⅱ组,未注入任何材料的3只为对照组,在相同的饲养条件下,分别于注入3、6、14个月时处死白色家兔,即刻切取标本切片,经10%甲醛固定后,石蜡包埋,HE及免疫组化染色观察。结果24只新西兰白色家兔中有6只兔(注入奥美定的4只,对照组的2只),分别观察到支气管肺炎、支气管黏膜鳞状上皮化生、肝点状坏死、间质性心肌炎等病理改变;其余18只兔均无明显改变。免疫组化Bcl-2、p53均为阴性,Hsp70、PCNA仅在极少数的肝、肾小管上皮细胞有阳性表达。结论奥美定注入兔体后动态观察3、6、14个月时处死,经病理形态学及免疫组化检测表明是安全的。     

奥美定中丙烯酰胺单体含量的分析

目的　探讨奥美定的配制材料注入兔体内 1年 ,丙烯酰胺单体含量的变化。方法　将 4只日本大耳兔分为A(2只 )、B(2只 )两组 ,A组以 10ml/kg奥美定的配制材料注入大耳兔体内 ,B组以 2ml/kg奥美定的配制材料注入大耳兔体内 ,至 12个月时取出 ,用高效液相色谱法分析丙烯酰胺单体含量。结果　奥美定中丙烯酰胺单体含量 <1.10× 10 -6g/ g ,而注入兔体内后取出的奥美定的配制材料中丙烯酰胺单体含量为 1.18× 10 -5～ 4 .88× 10 -5g/ g。结论　注入大耳兔体内的奥美定 12个月时丙烯酰胺单体含量较未注入的奥美定有所升高 ,但仍低于或接近国外同类材料中丙烯酰胺单体含量 ,因此是安全无毒性的     

奥美定中丙烯酰胺单体含量的分析

目的探讨奥美定的配制材料注入兔体内1年,丙烯酰胺单体含量的变化.方法将4只日本大耳兔分为A(2只)、B(2只)两组,A组以10 ml/kg奥美定的配制材料注入大耳兔体内,B组以2 ml/kg奥美定的配制材料注入大耳兔体内,至12个月时取出,用高效液相色谱法分析丙烯酰胺单体含量.结果奥美定中丙烯酰胺单体含量＜1.10×10-6 g/g,而注入兔体内后取出的奥美定的配制材料中丙烯酰胺单体含量为1.18×10-5～4.88×10-5 g/g.结论注入大耳兔体内的奥美定12个月时丙烯酰胺单体含量较未注入的奥美定有所升高,但仍低于或接近国外同类材料中丙烯酰胺单体含量,因此是安全无毒性的.     

TNFα和VEGF在激素性股骨头坏死中的变化

[目的]通过应用马血清、激素作用新西兰兔，诱导激素性股骨头坏死动物模型。分析TNFα、VEGF在激素性股骨头坏死中的作用。[方法]将20只健康新西兰兔随机分成2组，每组10只。A组为模型组。每只用马血清10ml／kg。经兔耳缘静脉注射。间隔2周，按5ml／kg剂量连续2d注射马血清各1次。间隔2周后，注射醋酸泼尼松龙。按7．5mg／kg腹腔注射3次。B组：正常对照组。动物注射激素5周后，采血，应用ELISA法测血清中TNF-α浓度。处死模型组，标本进行常规组织病理学检查，免疫组化分析股骨头VEGF的表达。[结果]模型组兔血清TNF-α浓度明显高于正常组（P〈0．01）。组织病理学检查显示：部分血管栓塞。骨髓腔内造血组织明显减少。免疫组化结果显示：骨细胞及骨髓组织VEGF表达明显减少。[结论]血清中TNF-α浓度升高及股骨头骨髓组织VEGF表达减少可能是激素性股骨头坏死发生的重要因素。     

介入治疗对兔VX2肝癌MMP-2/PCNA/VEGF表达的影响及其意义

目的：模拟不同方法介入治疗对兔VX2肝癌基质金属蛋白酶（MMP-2）、增殖细胞核抗原（PC-NA）、血管内皮生长因子（VEGF）表达的影响。方法：将VX2瘤细胞接种于40只新西兰大白兔肝左叶，建立VX2肝癌模型，随机分为4组，每组10只。介入治疗前MRI测量并记录肿瘤直径。经股动脉途径行肝固有动脉插管，分别注入生理盐水（对照组）、水化碘油（A组）、Ad-p53（B组）、Ad-p53＋水化碘油（C组）。术后1周处死动物，取肿瘤组织制作石蜡切片（HE）染色，镜下观察肿瘤组织坏死情况。免疫组化方法测定MMP-2／PCNA/VEGF的表达。结果：经肝动脉插管介入治疗1周后，A、B、C组肿瘤生长受到明显抑制，与对照组比较，P均〈0.05。单纯碘油栓塞后，肿瘤区的MMP-2、PCNA及VEGF的表达略有升高，与对照组相比P〉0.05；B组与C组的MMP-2、PCNA及VEGF的表达阳性率降低，与对照组相比，P均〈0.05；有转移的MMP-2、PCNA及VEGF的表达阳性率均高于无转移者（P〈0.05）；MMP-2与VEGF、PCNA之间之间有相关性（P〈0.05）。结论：碘油＋Ad-p53可抑制肿瘤的生长，抑制肿瘤新生血管形成，减少转移。MMP-2、PCNA、VEGF的增高预示着肿瘤的高转移、高增殖能力，肿瘤血管的高形成能力。     

参麦注射液对兔多脏器损伤的保护作用

目的 研究麦注射液对兔多脏器损伤动物模型的保护作用。方法 大耳家兔20只，随机分为对照组和治疗组，每组10只。对照组给每只家兔一次性耳缘静脉注射阿霉素10mg，以后隔日皮下注射间羟胺10mg，4周后即制成多脏器损伤动物模型。治疗组在对照组的基础上，每次注射阿霉素和间羟胺前，经耳缘静脉注射参麦注射液，每次10ml／kg。4周后剖杀取心、肝、肺、肾行病理组织学观察。结果 对照组兔心、肝、肺、肾细胞肿胀坏死，正常结构消失，间质炎性改变及局灶性水肿和硬化，有炎性细胞浸润和血栓形成。治疗组兔心、肝、肺、肾细胞肿胀、坏死明显减轻，间质炎性细胞明显减少，局灶性硬化明显减轻。结论参麦注射液对兔多脏器损伤有明显的保护作用。     

奥美定注入小香猪体内后生殖毒性的观察

目的 观察奥美定注入小香猪体内后的生殖毒性。方法 注入奥美定后观察小香猪母代及子代的生长、健康情况，抽出奥美定检测丙烯酰胺单体含量以及抽血查染色体及微核试验观察。结果 6只母代小香猪健康，2只与公猪交配，4个月及5个月后生出9只及4只子代小猪，健康情况亦良好。在半年及1年后分别抽出奥美定检测丙烯酰胺单体没有增加，共检测9只小香猪的染色体包括母代及子代，均未发现数目畸变及结构畸变，微核试验有细微的变化，并初步反映出与用药量大小呈正相关，但超量注射的一只动物(18.5ml/kg)变化的千分值仍在正常范围内。结论 从目前几项观察与检测指标看，实验量奥美定注入小香猪体内尚不具生殖遗传毒性。     

甘露醇注射速度对留置针穿刺部位血管损伤的实验研究

目的了解在25℃环境中以不同速度静脉注射20％甘露醇对兔耳静脉损伤情况。方法选择健康成年的新西兰兔36只，随机取4只作为对照组，另32只随机分为A、B、C、D四组各8只。均于兔两耳留置静脉留置针。对照组给予生理盐水5ml／kg 30min注入；另四组给予20％甘露醇5ml／kg分别于5min（A组）、10min（B组）、20min（C组）、30min（D组）注射完毕。均8h给药1次，连续3d。最后1次给药后处死兔，在穿刺点及以上2cm处取血管组织行病理检查。结果对照组血管壁增厚、血管周围炎症、纤维组织增生及血栓形成情况与其余四组之间比较，差异有显著性意义（均P〈0．05）；实验组四组比较，差异无显著性意义（均P〉0．05），D组血管壁增厚、血管周围炎症相对较多，A组血栓形成相对较多。结论注射甘露醇对穿刺部位血管均有损伤；根据注射甘露醇时的速度、持续时间不同，穿刺部位血管的损伤特点不一。     

硬膜外不同浓度辣椒辣素对兔痛阈、神经功能和脊髓神经元结构的影响

目的 观察硬膜外不同浓度辣椒辣素（CAP）对兔痛阈、神经功能和脊髓神经元结构的影响。方法健康新西兰雄性白兔36只，随机分为4组：对照组、C1、C2、C3组，每组9只。L6.7间隙硬膜外穿刺置管，C1、C2、C3组分别注入0．1％、0．25％、0．5％CAP1ml，对照组注入0．9生理盐水1ml。观察后肢热痛阈和神经功能改变，注药后24h，每组处死3只家兔，在光镜、电镜下观察L6.7脊髓神经元的病理改变。结果与对照组相比，注药后C1、C2、C3组痛阈延长（P〈0．05），随CAP浓度增加，痛阈延长时间增加，而神经功能评分下降。光镜、电镜下显示C2组神经元发生可逆性改变，C3组发生不可逆性改变。结论兔硬膜外注入CAP可延长痛阈，高浓度CAP可导致神经功能和脊髓神经元结构损害。     

血小板浓缩液的制备及促进兔尺骨骨折愈合方面的实验研究

目的：探索动脉血小板浓缩液，在无菌情况下的制备方法。通过免疫组化及物理测量，证实血小板浓缩液中含有多种生长因子，并对比分析其对骨折愈合不同时期的促进作用，为临床应用提供基础资料。方法：选用20只新西兰兔，随机分成2组，分别为空白组及血小板组。制作尺骨中段骨折动物模型，采用指钢板行内固定。在手术之前，先抽取兔股动脉血6ml左右，经枸橼酸钠抗凝后，加低速高速离心，提纯出白色的血小板浓缩液，将其注射回骨折断端。所有操作均为无菌操作。分别在1、2、4及6周处死兔，在骨折处取5mm骨组织标本。切片作PDGF免疫组化染色定性分析及测量骨痂直径定量分析。结果：①6ml的兔动脉血在低速及高速离心后，可分离出0．5ml的血小板浓缩液，浓度在正常兔血小板浓度的3倍以上。②免疫组化染色阳性产物呈棕黄色颗粒状。在空白组术后第1周及第2周PDGF因子为阴性表达，第4周、第6周为弱阳性表达；在血小板浓缩液组，随着处死时间延长，阳性表达率逐渐增高。在相同的处死时间，血小板浓缩液组阳性表达率明显高于空白组。空白组、血小板组兔尺骨骨折标本在1、2、4、6周，均有不同程度骨痂形成，其中以第6周兔骨痂最多，第1周兔以纤维连接为主，仅有少许骨痂形成。空白组与血小板组同期骨痂直径差异有显著性意义。结论：①少量的兔血在严格的实验条件下，能够制备出血小板浓缩液。②兔血小板浓缩液中确含有较高浓度的PDGF生长因子。③血小板浓缩液加速了骨折断端的愈合。     

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.