光动力学疗法对兔耳增生性瘢痕作用的初步研究

目的 探讨光动力学疗法对兔耳增生性瘢痕的作用。方法 建立兔耳增生性瘢痕模型后，将增生性瘢痕块随机分为血卟啉单甲醚（HMME）一光动力学疗法（PDT）治疗组和对照组（n=12）。观察瘢痕生长情况，建模术后28d取材行常规HE染色和胶原纤维VG染色，计算微血管密度，观察PDT对瘢痕的影响。结果 PDT治疗后瘢痕厚度显著降低，真皮层变薄；微血管数量及成纤维细胞数量减少，且主要位于真皮深层；胶原含量下降，胶原纤维排列较规则有序。结论 在瘢痕形成早期，HMME—PDT能够有效抑制兔耳瘢痕的增生，该方法有可能成为瘢痕预防与治疗的有效方法。     

ALA-PDT对兔耳增生性瘢痕抑制效应及作用机制的初步研究

目的：观察ALA-PDT（5-氨基酮戊酸光动力疗法）对兔耳增生性瘢痕形成的抑制作用及对转化生长因子β1（TGF-β1）表达的影响。方法：在兔耳腹侧面做直径1cm大小全层皮肤缺损创面3个/侧,共60个。随机分为以下三组：高浓度ALA-PDT组（n=20）：20%ALA介导PDT治疗;低浓度ALA-PDT组（n=20）：10%ALA介导PDT治疗;对照组（n=20）：不做治疗,待创面自然愈合。在创面形成术后的第6天、第13天分别进行ALA-PDT治疗,观察治疗组与对照组之间的瘢痕形成率、瘢痕增生指数、胶原纤维含量及TGF-β1表达情况的差异。结果：ALA-PDT治疗降低了瘢痕形成率,其中药物高浓度ALA-PDT组与对照组的差异有统计学意义（P〈0.01）;药物高浓度ALA-PDT组和药物低浓度ALA-PDT组的瘢痕增生指数、胶原纤维含量与对照组的差异有统计学意义（P〈0.05）;药物高浓度ALA-PDT组与对照组之间的TGF-β1的表达差异具有统计学显著性（P〈0.05）。结论：ALA-PDT对兔耳增生性瘢痕的形成有抑制作用,从而预防创伤后增生性瘢痕形成,该作用可能通过减少TGF-β1的产生而实现。     

5-氨基酮戊酸介导的光动力对人增生性瘢痕成纤维细胞的影响

目的 探讨5-氨基酮戊酸介导的光动力对人增生性瘢痕中成纤维细胞的影响.方法 选取人增生性瘢痕增生期组织5例,体外培养其中的成纤维细胞.取培养后的第3、4代成纤维细胞,添加5-氨基酮戊酸培养后应用激光共聚焦显微镜检测其代谢产物原卟啉IX在细胞内的积聚,并在5-氨基酮戊酸作用5h后给予635nm波长的红光照射,照射功率密度10mW/cm2,能量密度0.5～8.0J/cm2.24h后,应用CCK-8试剂盒分析5-氨基酮戊酸介导的光动力对成纤维细胞的杀伤作用.结果 5-氨基酮戊酸作用4h后,成纤维细胞中有原卟啉IX的积聚;作用5h后,原卟啉IX的积聚达到高峰,此时给予激光照射,成纤维细胞的成活率降低,并与照射强度呈量效依赖关系.结论 5-氨基酮戊酸介导的光动力能够杀伤增生性瘢痕中的成纤维细胞,是一种治疗增生性瘢痕的新方法.     

ALA光动力治疗兔耳增生性瘢痕模型的实验研究

目的：观察ALA光动力学疗法对兔耳增生性瘢痕的影响。方法：建立兔耳增生性瘢痕模型后,将增生性瘢痕块随机分为ALA-光动力学治疗组和对照组。观察ALA对增生性瘢痕微血管、成纤维细胞、胶原纤维的影响。结果：ALA-光动力学治疗后瘢痕厚度显著变薄;微血管及成纤维细胞明显减少;胶原纤维明显稀疏,排列较规则有序。结论：ALA-光动力学治疗能够显著抑制兔耳增生性瘢痕的增生。     

维拉帕米对兔耳增生性瘢痕作用的实验研究

目的　探讨钙通道阻滞剂维拉帕米对兔耳增生性瘢痕的作用。方法　建立兔耳外伤性皮肤早期瘢痕增生模型 ,将 2 4只兔随机平均分为 3组 ,每组 8只 ,各组瘢痕内分别注射维拉帕米 2 5 μl(0 .0 6 2 5mg) 瘢痕、曲安缩松 2 5 μl(1mg 瘢痕 )、生理盐水 2 5 μl(0 .2 2 5mg 瘢痕 ) ,1次 10d ,共 2次。观察瘢痕外形变化。治疗后 2 0d在瘢痕处取材 ,切片行HE及Masson染色。光镜下观察 ,计算瘢痕增生指数、切片内成纤维细胞数密度 ,计算机辅助图象分析测算切片内胶原纤维面密度。结果　与生理盐水组相比 ,维拉帕米组和曲安缩松组瘢痕均变软、变平 ,色泽变浅 ,瘢痕增生指数及胶原纤维面密度均降低 ,3组间成纤维细胞数密度无显著变化 ;维拉帕米组瘢痕增生指数高于曲安缩松组 ,胶原纤维面密度两组间无显著性差异。结论　外伤性兔耳早期增生性瘢痕局部注射维拉帕米可降低瘢痕内胶原含量 ,引起瘢痕萎缩。本实验条件下维拉帕米的促瘢痕萎缩作用弱于曲安缩松。     

电针抑制兔耳增生性瘢痕形成的作用研究

目的：探究电针刺激在抑制兔耳增生性瘢痕形成过程中的影响。方法：以成年新西兰雄性兔（24只）为实验对象,随机分为电针组、手针组、模型组、空白组,除空白组外其余各组在兔耳腹侧面造成创面以形成瘢痕组织,然后根据组别分别在血海与翳风穴给予不同的刺激,比较各组兔耳增生性瘢痕形成情况,测定增生性瘢痕的瘢痕增生指数、各样品组织中羟脯氨酸的含量及胶原纤维的排列。结果：电针治疗组的瘢痕增生指数与其他各组存在明显差异（P〈0．05）,HE染色在光镜下可见胶原纤维组织排列整齐度的增加及胶原纤维组织含量的降低。结论：电针可以抑制兔耳增生性瘢痕形成。     

吡非尼酮抑制兔耳增生性瘢痕作用的研究

目的探索局部注射吡非尼酮对兔耳增生性瘢痕的抑制作用。方法选取健康新西兰大耳白兔36只,在兔耳双侧分别构建增生性瘢痕模型后,将36只兔子随机平均分为溶剂对照组(A组)、吡非尼酮实验组(B组)和曲安奈德阳性对照组(C组)。待创面完成上皮化后开始给药。B组注射含150μg吡非尼酮的DMSO溶液,共30μl;A组注射等体积的DMSO;C组注射曲安奈德30μl,1次/d,连续注射3 d后改为1次/周,共2次。给药后第45天取材固定,常规HE染色及组织病理学分析,并计算瘢痕增生指数。通过Masson染色分析胶原纤维排列,PCR检测瘢痕组织中TGF-β1、TGF-β2和Col-Ⅰ等基因表达情况。结果 B组和C组与A组相比,吡非尼酮和曲安奈德均可显著降低兔耳瘢痕增生指数,减少瘢痕的高度,其颜色更加接近正常皮肤,胶原组织排列也更为整齐有序;瘢痕组织中TGF-β1、TGF-β2和Col-Ⅰ等的m RNA表达也均明显下降。结论吡非尼酮对兔耳增生性瘢痕的形成具有明显的抑制作用,其初步作用机制可能与抑制瘢痕组织中的TGF-β1和TGF-β2的表达有关。吡非尼酮可能通过下调TGF-β1与TGF-β2等基因的表达抑制了兔耳增生性瘢痕的形成。     

青蒿琥酯钠对兔耳增生性瘢痕中肥大细胞的影响

目的:探讨青蒿琥酯钠(Art)对兔耳增生性瘢痕中肥大细胞的影响.方法:用新西兰大白兔制作增生性瘢痕动物模型,兔左耳为Art组,用60mg/ml Art 20l/瘢痕作局部注射,每隔2天1次,共5次;右耳作为对照组,用5%NaHCO320μl/瘢痕作局部注射.HE、VG染色观察成纤维细胞和胶原形态,甲苯胺蓝染色作肥大细胞计数.结果:HE和VG染色显示:Art组真皮层较薄,胶原纤维排列较整齐;对照组真皮层较厚,胶原排列紊乱,有漩涡状结构.肥大细胞计数Art组为(5.27土1.27)个/HP,对照组为(10.67±.2.35)个/HP,两组比较差异有显著性意义.结论:青蒿琥酯钠能减少瘢痕中肥大细胞数量,抑制成纤维细胞增殖,减少胶原合成.[关键字]青蒿琥酯钠;动物模型;增生性瘢痕:肥大细胞     

微等离子体与点阵Er:YAG激光(2940nm)治疗兔耳增生性瘢痕的疗效比较

目的:探讨微等离子体与点阵Er:YAG激光(2 940nm)对兔耳增生性瘢痕的治疗效果。方法:同种属雌性新西兰大耳白兔6只,于每只兔耳腹侧面中段制作增生性瘢痕模型。28d后,将造模成功的瘢痕块随机分为3组,分别行微等离子体、点阵激光治疗和空白对照,治疗后27d取材,进行HE、Masson和天狼猩红染色,观察各组瘢痕组织中成纤维细胞数目、胶原分布特征及Ⅰ、Ⅲ型胶原纤维的构成比。结果:两个治疗组瘢痕组织变软变平且弹性增加,成纤维细胞数均较对照组减少,以P1asma组更为明显;胶原纤维的形态及排列向正常皮肤中的形态及排列转变,Ⅲ型胶原纤维的比例均增加,两治疗组间无显著差异。结论:微等离子体与点阵Er:YAG激光(2 940nm)治疗兔耳增生性瘢痕均有效,且在抑制瘢痕组织内成纤维细胞增生方面,微等离子体具有更明显的优势。     

中草药单体松萝酸抑制兔耳增生性瘢痕的作用研究

目的探讨中草药单体松萝酸对兔耳增生性瘢痕的抑制作用。方法建立兔耳增生性瘢痕模型,于兔左右侧耳形成4孔创面,23 d后给药;将24只大耳白兔随机分为4组(1 mg松萝酸和2 mg松萝酸的实验组、DMSO和曲安奈德的对照组),每组6只;实验组每孔创面注射含不同浓度松萝酸的DMSO 50μl;DMSO组注射等体积的DMSO溶剂;曲安奈德对照组注射曲安奈德50μl。每周给药1次,共4次,于给药35 d后取材。通过HE染色观察组织学变化,并检测瘢痕的增生指数;通过Masson染色检测胶原排列情况;应用CD31免疫组织化学染色检测瘢痕内血管的变化。结果 2 mg松萝酸实验组可以显著抑制兔耳增生性瘢痕的形成,明显改善瘢痕的颜色和厚度,且瘢痕增生指数也明显减少,胶原组织排列有明显改善。CD31染色结果表明,2 mg松萝酸实验组可显著抑制瘢痕内的血管新生。结论 2 mg松萝酸具有抑制兔耳增生性瘢痕内血管新生的作用,从而抑制增生性瘢痕的形成。     

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.