糖尿病大鼠深Ⅱ度烫伤后真皮成纤维细胞的生物学特征

目的观察糖尿病（DM）大鼠深Ⅱ度烫伤肝创面皮肤组织及真皮成纤维细胞（Fb）生物学特征，探讨其与DM创面愈合延迟的病理关系。方法将90只SD火鼠分为DM组（50只）和NM组（NM，40只），DM纽大鼠制成链脲菌索绣导的DM模型，之后将两纰大鼠造成10％TBSA深Ⅱ度烫伤。各组大鼠均于伤前及伤后3、7、14、21d（每组每时相点6只）留收创面皮肤组织标本，对其各项生物学特征进行检测。结果与NM组大鼠比较，DM组伤前真皮厚度明显变薄（P〈0．01）、胶原排列紊乱、真皮内出现大量的慢性炎性细胞浸润，皮肤糖含量升高（DM组2．77mg／g，NM组0．85mg／g，P〈0．01）和高级糖基化终产物（AGEs）蓄积。深Ⅱ度埂伤后，DM组大鼠Fb的S期细胞百分比和羟脯氨酸合成量明显低于NM组，而Fb的凋亡率却明显高于NM组（P〈0．05或0．01）。结论DM大鼠合并深Ⅱ度烫伤后真皮中Fb的乍物学特征异常，可能与局部皮肤组织糖含量升高和AGEs的蓄积有关，推测是DM患者容易并发慢性溃疡的病理基础之一。     

依那普利拉对严重烫伤大鼠早期心肌损害的防治作用

目的了解依那普利拉对烧伤后早期心肌损害的防治效果。方法将60只SD大鼠制成30％TBSAⅢ度烫伤模型，分为单纯烫伤组（30只，伤后常规补液）和依那普利拉组（30只，伤后立即一次性腹腔注射依那普利拉1mg／kg并行常规补液）。另取6只大鼠不致伤作为正常对照组。检测正常对照组及2组烫伤大鼠伤后1、3、6、12、24h血清心肌肌钙蛋白I（cTnI）的含量、心肌型肌酸激酶同工酶（CK—MB）的活性，并观察心肌组织病理学变化。结果（1）单纯烫伤组大鼠伤后各时相点cTnI、CK—MB均显著高于正常对照组（P〈0．01）。依那普利拉组伤后各时相点cTnI为（1．32±0．12）-（2．47±0．22）μg／L，均显著低于单纯烫伤组[（6．42±0．96）-（15．10±3．69）μg／L，P〈0．01]；其各时相点CK—MB活性为（438±68）-（5569±322）U／L，亦均低于单纯烫伤组[（2556±74）-（8047±574）U／L，P〈0．05或P〈0．01]。（2）与正常对照组比较，单纯烫伤组伤后出现心肌细胞浊肿、间质血管扩张充血、炎性细胞浸润等病理改变；依那普利拉组病变程度较之减轻。结论大鼠严重烫伤后早期心肌组织受损明显，依那普利拉能显著减轻这些损害。     

胰岛素强化治疗对烫伤大鼠心肌保护作用的研究

目的 了解胰岛素强化治疗对重度烫伤大鼠心肌的保护作用，并探讨其作用机制。方法 将18只SD大鼠分为3组，每组6只。强化组及烫伤组大鼠背部脱毛造成30％TBSA的Ⅲ度烫伤。强化组伤后即输注胰岛素等渗盐水（含胰岛素0．12U／m1）及100g／L葡萄糖，使大鼠血糖水平控制在4．0～6．6 mmol／L之间，补液总量为2ml·kg^-1。·％TBSA^-1·8h^-1；烫伤组伤后仅给予等渗盐水，总量同前。假伤组模拟烫伤，伤后补充生理量的液体。于伤前及伤后1、2、3、4、5、6 h 抽取大鼠静脉血测定其血糖值。各组大鼠伤后均经右颈动脉插管人左心室并连接生理记录仪，观察左心室收缩压（LVSP）及左心室舒张末期压（LVEDP）。伤后6h，处死各组大鼠，留取左心室组织标本用于心肌细胞肌钙蛋白T的检测。结果 烫伤组大鼠伤后1～6h的血糖值为（7．6±1．7）～（8．4±4．7）mmol／L，均高于强化组[（4．5±0．9）～（5．2±1．3）mmol／L，P〈0．01]。伤后1h，烫伤组LVSP[（60±11）mmHg（1mmHg=0．133kPa）]降低、LVEDP[（21．3±11．3）mmHg]升高，与强化组[（72±8）、（11．7±5．2）mmHg]比较，差异有统计学意义（P〈0．05）。烫伤后各组大鼠肌钙蛋白T在心肌细胞内大量缺失，而强化组缺失程度明显低于烫伤组（P〈0．05）。结论 胰岛素强化治疗对重度烫伤大鼠左心室功能具有明显的保护作用，此作用可能与抑制心肌细胞蛋白的缺失有关。     

内皮素-1受体拮抗剂PD142893对肝硬化大鼠肝脏Ⅰ型胶原、Ⅲ型胶原表达的影响以及和肝纤维化关系

目的探讨内皮素受体拮抗剂是否对CCl4引起的大鼠肝纤维化有阻滞作用。方法实验中采用的是通过CCl4损伤引起的肝硬化门脉高压大鼠模型，随机分为正常对照组、肝硬化模型组、PD142893（ETA／B双受体拮抗剂）治疗组。治疗组在用CCl4造模的同时皮下注射PD142893（12．5μg／kg），2次／d，直到造模结束，取部分肝组织用甲醛固定后行HE染色和Masson染色并进行肝硬化分级；然后根据染色结果制作组织芯片并行免疫组化染色，检测Ⅰ型胶原、Ⅲ型胶原的蛋白表达并进行半定量分析。取部分肝组织用RT-PCR法检测Ⅰ型胶原、Ⅲ型胶原的mRNA表达并进行半定量分析。结果肝硬化分级和Masson染色胶原半定量结果证实肝硬化模型组、PD治疗组大鼠肝纤维化程度明显加重，与对照组比较有非常显著性差异（P〈0．01）；而PD治疗组的肝纤维化程度较模型组明显减轻，差别有显著性意义（P〈0．05）。Ⅰ型胶原、Ⅲ型胶原免疫组化蛋白表达及mRNA表达结果证实肝硬化模型组与对照组、PD治疗组比较明显上调（P〈0．05）。结论ET A/B双受体拮抗剂可以有效地下调CCl4引起的肝纤维化大鼠的Ⅰ型胶原、Ⅲ型胶原的蛋白表达和mRNA表达，进而抑制大鼠肝纤维化的发展。     

嵌合体大鼠诱导异种皮肤移植免疫耐受的初步研究

目的 探讨嵌合体大鼠诱导异种皮肤移植免疫耐受的可行性。方法 采集兔骨髓干细胞，经行宫内胎鼠移植以及对新生子鼠行肝内注射，制作兔骨髓干细胞嵌合体大鼠模型。6周后将15只嵌合体大鼠分为A组（8只）、B组（7只）。将A组大鼠皮肤移植给供髓兔，将7只非嵌合体大鼠皮肤移植给非供髓兔作A组对照；将B组大鼠、7只非嵌合体大鼠（B组对照）皮肤同时移植给供髓兔。记录移植后皮片成活时间、创面愈合时间。结果A组对照移植皮片成活（9．3±1．8）d，创面于（20．9±2．1）d愈合；A组移植皮片成活（15．1±2．6）d，创面于（18．5±1．3）d愈合。B组及其对照移植皮片的成活时间、创面愈合时间与A组相似。与各自对照皮肤移植相比，A、B组皮片成活时间延长（P〈0．01），创面愈合时间缩短（P〈0．05或P〈0．01）。结论 嵌合体大鼠行异种皮肤移植后能诱导移植皮片免疫耐受．使其成活时间明显延长．创面愈合时间缩短。     

碱性成纤维细胞生长因子对深Ⅱ°烫伤大鼠创面再上皮化过程中表皮干细胞的生物学作用

目的观察碱性成纤维细胞生长因子（bFGF）促进大鼠深Ⅱ°烫伤创面再上皮化作用及对表皮干细胞增殖和迁移的影响。方法66只Wistar大鼠随机分为A组（正常对照组，n=6）、B组（单纯烫伤组，n=30）、C组（bFGF治疗组，n=50）。利用大鼠5％深Ⅱ°烫伤模型，于伤后1、3、7、14和21d采取创面边缘皮肤标本，免疫组织化学染色技术检测创面边缘上皮及深层皮肤附件上皮整合素-β1（integrin-β1）、角蛋白19（K19）和PCNA以及上皮钙依赖性黏附素（E—cadherin）的表达情况。结果正常皮肤中，整合素-β1、角蛋白19、PCNA和E-cadherin表达主要集中在Wistar大鼠表皮层的基底部及毛囊球部。皮肤烫伤初期，以上指标变化不显著。7—14d时，整合素-β1和角蛋白19同时阳性表达的细胞有所增强，PCNA和E—cadherin的表达增强。当局部外用bFGF后，创伤初期（1—3d）组织中的表达差异无统计学意义（P〉0．05），7—14d，阳性表达角质形成细胞出现在创缘的棘层与颗粒层，毛囊根部的阳性标记细胞强于对照组。结论bFGF促进深Ⅱ°烫伤大鼠创面愈合与加速启动创缘表皮基底层的表皮干细胞以及皮肤附件上皮的迁移有关。     

晚期糖基化终产物受体在糖尿病大鼠自体移植静脉中的表达及氨基胍的干预作用

目的 探讨晚期糖基化终产物受体（RAGE）在糖尿病大鼠自体移植静脉中的表达及氨基胍对其内膜增生的干预作用。方法 雄性SD大鼠60只，随机均分为氨基胍组、蒸馏水组及对照组，前2组行链脲佐菌素腹腔注射建立糖尿病模型，并分别用氨基胍或蒸馏水灌胃，对照组为未作处理的正常大鼠。3组均建立自体静脉移植模型后，于术后第7d及14d测定血清晚期糖基化终产物（AGE）含量，同时取自体静脉移植标本进行组织形态学观察，Westernblot和免疫组织化学染色方法检测RAGE及NF-KBp65的蛋白表达，半定量RT-PCR检测RAGE及NF—xBp65mRNA的表达。结果 术后第7d及14d，相对于对照组大鼠，蒸馏水组糖尿病大鼠自体移植静脉内膜增生加重，血清AGE含量增加，RAGE和NF—kB p65mRNA和蛋白表达增强，差异均有统计学意义（P〈0．05）；氨基胍组血清AGE含量、NF—kB p65蛋白和mRNA表达及内膜增生均较蒸馏水组减少或减轻（P〈0．05），与对照组相比差异无统计学意义（P〈0．05）。结论 糖尿病大鼠自体移植静脉RAGE表达增强，激活NF—kB，与移植静脉内膜增生关系密切；氨基胍抑制AGE的产生，可阻断AGE-RAGE结合，减轻内膜增生。     

晚期糖基化终产物及其受体对大鼠阴茎海绵体组织中内皮素-1活性的影响

目的：通过观察大鼠阴茎海绵体组织中晚期糖基化终产物（AGEs）及其受体（RAGE）的变化对内皮素1（ET-1）活性的影响，探讨AGEs在糖尿病性勃起功能障碍（DMED）发生发展中的作用。方法：成年雄性SD大鼠60只，随机取40只用于制作糖尿病模型，造模后共27只大鼠成模，将其分为两组：糖尿病（DM）组15只和糖尿病＋氨基胍给药（DM＋AG）组12只；另20只大鼠平分为两组：正常对照（NC）组和正常对照＋氨基胍给药（NC＋AG）组；两组氨基胍（AG）给药组大鼠造模后即在其饮水中按1g／L剂量加入AG。饲养8周后取各组大鼠阴茎海绵体组织，一部分用于免疫组化法观察分析AGEs及其受体的分布和表达，剩余部分匀浆后检测AGE-肽（AGE-P）含量和ET-1活性。结果：DM组阴茎海绵体组织中AGEs和RAGE的表达、AGE-P含量及ET-1活性明显高于正常对照组（P〈0．05）；正常对照组与NC＋AG组间比较在各项指标上则无明显差异（P〉0．05）。结论：糖尿病状态下AGEs与RAGE的结合效应可以引起大鼠阴茎海绵体组织中ET-1活性的增强，从而促进DMED的发生发展。     

β内啡肽与μ型-阿片受体在深Ⅱ度烫伤大鼠创面愈合过程中的表达

目的观察β内啡肽和μ型-阿片受体（MOR）在深Ⅱ度烫伤大鼠创面愈合过程中的表达。方法将36只Wistar大鼠随机分为对照组（6只）、烫伤组（30只）。烫伤组大鼠被造成5％TBSA深Ⅱ度烫伤，对照组仅模拟烫伤。于伤后即刻及伤后3、7、14、21d取创面组织，采用免疫荧光标记法检测B内啡肽和MOR的表达情况。结果对照组大鼠皮肤组织内β内啡肽和MOR主要分布于表皮、真皮交界的周围神经纤维、表皮的角质形成细胞、真皮的成纤维细胞中，强度较弱。伤后3d，烫伤组B内啡肽表达达峰值（196±16，P＜0．01），在皮肤全层均有表达；MOR集中表达在基底层和基底上的角质形成细胞。伤后7、14d烫伤组B内啡肽仍大量表达。伤后7d，烫伤组MOR的表达进一步增强，胶原排列紊乱；14d时部分创面再上皮化，MOR表达达高峰（306±23，P＜0．01）。伤后21d，烫伤组创面完全再上皮化，周围神经末梢接近并抵达表皮、真皮交界，胶原排列较整齐，β内啡肽的表达（31±24）与对照组（30±18）接近；但MOR的表达（56±16）仍然高于对照组（28±15）。结论烫伤后β内啡肽和MOR的表达具有一定的时效性，这种变化可能影响了创面愈合。     

2型糖尿病大鼠后肢缺血模型的建立及评价

目的建立2型糖尿病大鼠后肢缺血模型并进行评价,为后续的干预实验提供研究平台。方法将15只SD大鼠随机分为正常对照组、糖尿病组及糖尿病后肢缺血组,每组5只。糖尿病组及糖尿病后肢缺血组的10只大鼠均给予高脂饮食喂养4周后,腹腔注射链脲佐菌素（STZ,40mg／kg）以建立2型糖尿病模型。糖尿病后肢缺血组大鼠建模成功后行双侧髂总动脉结扎术以建立后肢缺血模型,正常对照组和糖尿病组大鼠仅分离髂总动脉,不予结扎。2周后对3组大鼠股动脉的起始段行彩色多普勒超声检查,以检测股动脉的血流峰值速度和血流加速时间;取缺血部位的小腿三头肌及大腿股四头肌组织,分别行HE染色及免疫组化SP染色,以观察3组大鼠肌细胞的营养状况及血管再生情况。结果后肢缺血模型建模2周后,正常对照组、糖尿病组和糖尿病后肢缺血组大鼠的血流峰值速度分别为（22．49±3．02）cm／s、（17．36±2．60）cm／s和（11．23±1．26）cm／s,血流加速时间分别为（0．080±0．009）S、（0．120±0．009）S和（0．160±0．020）s,糖尿病后肢缺血组大鼠的股动脉血流峰值速度小于正常对照组和糖尿病组（P〈0．05）,而血流加速时间较长（P〈0．05）。HE染色结果显示：糖尿病后肢缺血组大鼠小腿三头肌的结构破坏,有大量炎症细胞浸润,肌肉损伤程度重于正常对照组和糖尿病组。免疫组化sP染色结果显示：糖尿病后肢缺血组大鼠大腿股四头肌的毛细血管密度[（1．40±0．55）个／HPF]小于正常对照组[（6．80±0．84）个／HPF]及糖尿病组[（4．60±0．55）个／HPF],差异均有统计学意义伊〈O．05）。结论对SD大鼠给予高脂饮食联合小剂量STZ注射可以成功诱导2型糖尿病模型,在此模型基础上结扎髂总动脉可以成功制备糖尿病后肢缺血模型。     

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.     

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.     

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.