防粘连几丁糖膜的制备和部分性能测定

目的制备防粘连几丁糖膜及测定其部分性能.方法在透析后的几丁糖与明胶混合液中加入戊二醛交联后置入冻干机冻干制得几丁糖膜.测定湿润时间、吸水量和吸水率表示其吸水性能.动物实验研究膜的止血性能,观察与创面的粘附情况,记录出血时间,以膜或纱布中Hbo光度吸收值表示出血量.结果几丁糖膜具有良好的吸水性能,适合用于止血.与创面粘附良好,几丁糖膜组、纱布组的出血时间分别为(78.25±6.42)s、(119.05±11.39)s,Hb光度吸收值为0.76±0.51、1.63±0.72,明显优于纱布对照组(P＜0.01).结论几丁糖膜具有一定的止血性能.     

纤维蛋白原-胶原海绵片在肝手术创面的止血及组织封闭作用的动物实验研究

目的探讨纤维蛋白原鄄胶原海绵片在手术创面的止血性能、封闭创面的效果及在体内降解吸收的状况。方法将SD大鼠20只随机分成实验组和对照组。实验组用纤维蛋白原鄄胶原海绵片进行止血,对照组用明胶海绵片止血。结果在大鼠肝表面的切口,两种止血材料均能即刻止血。纤维蛋白原鄄胶原海绵片与切口粘附紧;而明胶海绵片较易脱落。在大鼠左肝前叶切除术中,纤维蛋白原鄄胶原海绵片组在止血时间及出血量的指标上均优于明胶海绵片组(P<0.05)。组织学检查:创面炎症消退、止血材料降解和促肝细胞再生,实验组均优于对照组。结论纤维蛋白原鄄胶原海绵片能有效地止血,与创面的粘附力强,吸收降解快,且能诱导肝创面肝细胞再生。因而,纤维蛋白原鄄胶原海绵片是一种安全的局部止血、组织封闭和促进细胞再生的生物材料。     

胶原海绵止血功能的实验研究

目的 验证国产胶原海绵的止血性能。方法 选用健康成年SD大鼠20只,随机分为二组,行肝脏和切口,分别用胶原及明胶少绵止血,观察止血情况;切除肝左前叶造成标准肝创伤模型,分别用二种海绵止血,观察止血情况,并记录即时止血时间及出血量。术后7、14及20天剖腹观察腹腔内粘连、腹腔内感染及肝脏愈合情况,并切除部分再生肝组织进行组织学检查。结果 胶原海绵下肝创面粘附良好,即时止因时间及出血量均明显优于对照组（P＜0.05）。组织切片显示胶原海绵吸收、降解快,可诱导肝细胞再生。结论 胶原海绵止血性能良好,能有效导肝再生,吸收降解快,使用方便,有应用、推广价值。     

医用胶原蛋白海绵治疗重度肝破裂的临床研究

目的：探讨医用胶原蛋白海绵对重度肝破裂创面的治疗作用。方法：将重度肝破裂患者以入院先后为序，随机分成治疗组（68例）和对照组（64例）。治疗组和对照组分别用医用胶原蛋白海绵片和明胶海绵片对肝创面进行止血和填塞。结果：治疗组的止血时间为(19.65±1.28)min，术中出血量为(301.57±56.18)mL均少于对照组［分别为(34.3±1.2)min及(642.3±61.8)mL］(均P<0.05)。治疗组术后腹腔引流量为(380.45±12.34)mL,并发胆瘘(1.5%)及再出血(3.0%)均少于对照组［分别为(693.2±219.4)mL,6.3%及9.5%］(均P<0.05);治疗组术后住院时间(24.01±4.89)d短于对照组(35.8±5.9)d(P<0.05)。术后CT复查显示治疗组创面肝组织修复时间(30.30+6.42)d短于对照组(62.1±7.2)d(P<0.05)。结论：胶原蛋白海绵对肝创面止血效力强于明胶海绵，与创面的黏附力强，术后并发症少，恢复快，是一种治疗肝破裂的有效、安全而可靠的生物材料。     

苦参碱对兔耳增生性瘢痕治疗作用的组织形态学研究

目的:研究苦参碱（matrine,Mat）对兔耳增生性瘢痕治疗作用。方法:利用兔耳腹侧面增生性瘢痕模型,采用组织形态学的方法对比研究苦参碱在兔耳增生性瘢痕形成过程中的影响。结果:兔耳腹侧面增生性瘢痕局部注射苦参碱后,按时间段取材;VG和HE染色显示真皮层明显变薄,成纤维细胞数量明显减少,胶原排列趋于一致;12周后,对照组苦参碱组的增生指数、成纤维细胞数密度、胶原密度分别为3.25±0.89/2.15±0.12,4517.5±879.6/3551.2±234.1,39.89±14.12/28.75±10.87。结论:苦参碱能抑制兔耳增生性瘢痕的增殖过程,使瘢痕组织纤维化程度明显减轻。     

医用几丁糖预防髌骨骨折后膝关节粘连的临床观察

目的研究医用几丁糖对髌骨骨折后膝关节功能障碍发生的影响.方法对40例因髌骨骨折行内固定治疗的患者,24例术中于关节腔内涂布几丁糖作为几丁糖组;另16例未用作为对照组.观察术后1个月和1年时膝关节的伸屈活动度.结果40例均获随访,术后1个月时膝关节活动度几丁糖组(104±23°)显著＞对照组(72±16°),P＜0.01;术后1年几丁糖组(165±38°)也显著＞对照组(110±31),P＜0.05.结论医用几丁糖能有效预防髌骨骨折后膝关节粘连的发生.     

间歇性脾动脉阻断在医源性脾损伤中的应用

目的总结间歇性脾动脉阻断联合明胶海绵压迫在医源性脾损伤保脾手术中的应用。方法回顾分析2013年1月至2015年12月徐州医学院附属医院收治的胃癌手术操作相关的Ⅰ、Ⅱ级脾损伤病例共18例,所有病例均采用间歇性脾动脉阻断联合明胶海绵压迫创面止血,脾动脉阻断时间首次为15 min,如仍有出血,再依次继续阻断10 min、5 min,然后解除阻断及压迫观察止血效果。结果14例经阻断后压迫15 min成功止血,4例经阻断压迫25 min成功止血。术后均无再次出血、腹腔脓肿、脾脏坏死等并发症,术后3周内血小板计数均500×10~9/L。结论对于工级、Ⅱ级医源性脾损伤间歇性脾动脉阻断联合明胶海绵压迫止血安全有效。     

医用几丁糖预防逆行带锁髓内钉固定术后膝关节黏连的临床观察

[目的]观察医用几丁糖对股骨逆行带锁髓内钉固定术后,预防膝关节黏连方面的作用。[方法]56例因股骨远端骨折行膝关节开放、股骨逆行带锁髓内钉内固定术的患者中随机选择29例,术中关节腔内涂布2%几丁糖4 m l作为几丁糖组;另27例常规手术不作任何处理作为对照组。双盲法观察术后6周和1年时膝关节的伸屈活动度。[结果]56例均获随访,术后6周时膝关节活动度几丁糖组伸屈104°±23°、对照组伸屈72°±16°,有显著差异(P<0.01);术后1年几丁糖组伸屈161°±30°、对照组105°±28°,有显著差异(P<0.05)。[结论]医用几丁糖能有效预防股骨逆行带锁髓内钉固定术后膝关节黏连的发生。     

胶原蛋白海绵对腔镜甲状腺手术止血效果的研究

甲状腺肿块切除后常导致局部甲状腺创面出血、创面渗液等,如不及时止血和引流,可能导致纤维化包块形成~([1]),所以甲状腺手术后大多需创面止血,缝合甲状腺组织缺损部位,同时留置颈部引流管以排出术后创面渗血、渗液。胶原蛋白海绵是一种新型医用生物材料~([2]),由细胞外基质主要成分胶原蛋白发展而来,具有可降解、生物相容性好、止血快和不易发生感染等优良的生物学特性,被广泛应用于医学创面修复领域~([3-4])。多项研究表明,采用胶原海绵填充手术缺     

几丁糖与透明质酸钠治疗肘关节粘连的对比研究

目的比较医用几丁糖与透明质酸钠预防肘关节粘连的临床疗效.方法对43例肘关节僵硬患者进行手术松解,其中15例术后关节腔内涂布2%几丁糖,14例术后关节腔内涂布1%透明质酸钠,另14例术后关节腔内涂布生理盐水为对照组,观察术后肘关节伸屈活动度改善程度以评定疗效.结果本组病例均获随访,随访时间10～87月,平均42月.几丁糖组术后肘关节平均活动度恢复到(97.7±16.5)°,比术前增加(62.0±12.7)°;透明质酸钠组术后肘关节平均活动度恢复到(86.1±18.6)°,比术前增加(48.9±15.1)°,对照组术后肘关节平均活动度恢复到(70.0±15.1)°,比术前增加(36.1±11.5°).几丁糖组术后肘关节伸屈活动度增值大于透明质酸钠组(P＜0.05),透明质酸钠组术后肘关节伸屈活动度增值大于对照组(P＜0.05).结论医用几丁糖和透明质酸钠均具有减轻或预防肘关节松解术后再粘连的形成作用,几丁糖疗效优于透明质酸钠.     

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.