补肾生血药促进大鼠缺血后肢血管新生的实验研究

目的:探讨补肾生血药对缺血后肢大鼠外周循环中骨髓来源内皮祖细胞(EPC)的影响及缺血组织血管新生的影响。方法:建立大鼠后肢缺血模型,喂食补肾生血药,1周后细胞培养观察外周血EPC数量变化,4周后检测缺血组织微血管密度及血管内皮生长因子(VEGF)的表达情况。结果:实验组大鼠外周血培养的EPC(89.1±10.3/mm2)明显高于对照组(48.6±7.5/mm2)(P<0.01),缺血组织微血管密度(288.76±12.54)和VEGF表达(0.233±0.014)均高于对照组(224.84±5.87),(0.162±0.018,P<0.05),且外周血EPC数量与微血管密度之间具有显著相关性(P<0.01)。结论:补肾生血药通过动员骨髓EPC的迁移、分化、促进局部的血管新生,达到改善供血目的。     

骨髓干细胞移植促进缺血肢体血管新生的研究

我们通过建立大鼠肢体缺血模型。采用骨髓内皮祖细胞(EPC)移植于缺血肢体，观察缺血组织血管新生及血管内皮生长因子(VEGF)的表达情况，探讨自体骨髓干细胞移植在治疗肢体缺血性疾病中的价值。     

血管内皮生长因子转染内皮祖细胞治疗大鼠缺血后肢的研究

目的 使用血管内皮生长因子(VEGF)转染内皮祖细胞(EPC)治疗大鼠缺血后肢,观察EPC、VEGF转染EPC对大鼠缺血后肢的新生血管和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的VEGF基因真核表达载体转染入骨髓来源的EPCs后通过尾静脉注射人大鼠体内,并与使用磷酸盐缓冲液(PBS)或EPC的动物进行比较,观察转染VEGF的EPCs在缺血部位的聚集和形成新生血管的情况.结果 (1)动物总残肢率比较,CELL组、VEGF组较PBS组明显增加的肢体恢复率(P<0.05),CELL组肢体恢复率较VEGF组差(P<0.05).(2)毛细血管密度与PBS组比较,各时间点中CELL、VEGF组MVD均明显增多(P<0.05).(3)缺血肢体VEGFa的表达:VEGF组的VEGF蛋白表达较PBS组、CELL组、明显增多(P<0.05);(4)手术后7、14、28 d,与PBS对照组比较,CELL、VEGF组细胞的血流灌注有较大程度的恢复(P<0.01).结论 VEGFa基因转染EPCs对缺血部位的血管新生有重要影响,联合应用VEGFa基因和EPCs治疗缺血后肢有较好的协同作用.     

血管内皮生长因子-碱性成纤维细胞生长因子基因治疗家兔肢体缺血的研究

目的　了解血管内皮生长因子 (VEGF)和碱性成纤维细胞生长因子 (bFGF)联合克隆基因 (VEGF bFGF)治疗兔下肢动脉缺血模型后新生血管和侧支形成状况。方法　应用 40只家兔制成下肢缺血模型 ,其中VEGF bFGF组 10只 ,VEGF组 12只 ,空载体组 8只 ,生理盐水 (NS)组 10只。构建pcDNA3 /VEGF和pcDNA3 /VEGF bFGF真核表达载体。转染缺血部位肌组织 ,行下肢血管造影。结果　血管造影计数显示 ,VEGF bFGF组在转染后 14d(1.98± 0 .2 2 ) ,2 8d (1.81± 0 .5 2 ) ,5 6d(2 .2 1± 0 .44 )和 3个月 (2 .10± 0 .2 2 ) ;VEGF组在 2 8d(1.3 8± 0 .2 9) ,5 6d(1.94± 0 .2 5 )和 3个月 (2 .2 4± 0 .3 1) ,新生血管形成较对照组显著增加 (P <0 .0 5 )。结论　VEGF bFGF真核表达载体可以获得局部高效表达 ,刺激新生血管生成 ,建立侧枝循环 ,改善肢体缺血。     

兔肝癌肝动脉栓塞后肿瘤血管生成的变化

目的　观察肝癌肝动脉栓塞后肿瘤组织血管生成的变化。方法　建立兔肝癌模型 ,随机分栓塞组 (n =10 )和对照组 (n =10 )。于接种后 14d经肝动脉注入超液化碘油 (栓塞组 )或等量生理盐水 (对照组 )。栓塞后第 7天取肿瘤 ,免疫组织化学方法检测肿瘤组织微血管密度 (MVD)及血管内皮生长因子 (VEGF)蛋白的表达 ,逆转录 聚合酶链反应 (RT PCR)检测VEGFmRNA的表达。结果　栓塞组MVD (2 8.6± 10 .6)与对照组 (16.3± 6.9)比较差异有非常显著性 (t =3 .0 83 ,P <0 .0 1) ;栓塞后VEGF蛋白 (t =3 .0 75 ,P <0 .0 1)及VEGF165mRNA (t =3 .95 4,P <0 .0 0 1)表达水平显著增高 ;在栓塞组和对照组 ,VEGF蛋白表达均与MVD呈正相关 (r分别为 0 .69和 0 .72 ,P <0 .0 5 )。结论　肝动脉栓塞术可通过促使肿瘤细胞VEGF表达上调 ,从而促进肿瘤的血管生成 ,如果将介入栓塞与抗血管生成治疗相结合 ,可望提高栓塞治疗效果     

腺相关病毒介导的血管内皮生长因子基因与内皮祖细胞联合治疗肢体缺血

目的探讨腺相关病毒(AAV)介导的人血管内皮生长因子165(hVEGF165)基因转染的兔骨髓内皮祖细胞(EPCs)自体移植对于移植细胞存活率和缺血肢体血管再生的影响。方法构建、制备携带hVEGF165基因或β-半乳糖苷酶(β-gal)基因的AAV载体AAV-hVEGF165和AAV- LacZ;用AAV—hVEGF165和AAV-LacZ分别转染体外培养的EPCs,得到AAV/VEGF-EPC和AAV/LacZ-EPC,用RT-PCR、免疫细胞化学、流式细胞术检测外源基因的表达。分别用AAV/VEGF-EPC、AAV/LacZ-EPC和PBS自体移植于兔右下肢缺血的肌组织,28 d后行双侧肢体血流和免疫组织化学检测。结果AAV/VEGF—EPC和AAV/LacZ-EPC内可检测到外源基因的表达。AAV/VEGF—EPC、AAV/LacZ-EPC和PBS组患/健侧血流比值、毛细血管密度分别为0.73±0.21、0.64±0.13、0.45±0.10;(962±291)、(557±132)、(361±69)/mm2。AAV/VEGF-EPC和AAV/LacZ-EPC组移植成活的EPCs密度分别为(330±81)/mm2和(204±55)/mm2。结论AAV能够高效将外源基因转入EPCs,对其进行基因修饰。自体移植AAV-hVEGF165转染的EPCs可提高其移植存活率和增强其促进缺血肢体血管再生能力。     

骶骨脊索瘤中Survivin、VEGF的表达及其与血管生成的相关性研究

[目的]研究骶骨脊索瘤组织中生存素(survivin)、血管内皮生长因子(vascular endothelial growth factor,VEGF)与微血管密度(microvessel density,MVD)的表达情况及三者的相关性,为骶骨脊索瘤的预后判断和靶向治疗提供理论依据.[方法]应用免疫组织化学(SP)法检测30例人骶骨脊索瘤组织和10例癌旁组织中survivin、VEGF的表达,利用CD34标记组织中的新生血管.[结果]①Survivin、VEGF在骶骨脊索瘤中的阳性表达率分别为70.0％、76.7％,均高于瘤旁组织(P＜0.05).骶骨脊索瘤中MVD值(27.2±10.70) /mm2高于瘤旁组织(8.90±3.11) /mm2(P＜0.05);②Survivin阳性表达的骶骨脊索瘤组织中MVD值(30.71±10.35) /mm2明显高于Survivin阴性组(19.00±6.25) /mm2 (P＜0.05).VEGF阳性组MVD值(29.43±10.87) /mm2明显高于VEGF阴性组(19.86±6.18) /mm2(P＜0.05);③Survivin与VEGF的表达呈正相关(r=0.499,P=0.005);④Survivin的表达与患者肿瘤有无局部浸润、是否复发相关(P＜0.05).[结论]骶骨脊索瘤组织中survivin和VEGF表达水平较高,两者的表达呈正相关且与骶骨脊索瘤中的MVD均呈正相关,二者对骶骨脊索瘤的血管生成可能起协同、正向调节作用.     

犬自体骨髓干细胞在缺血肢体中新生血管形成中的作用

目的:探讨犬自体骨髓干细胞在缺血组织的新生血管形成中的作用.方法:抽取犬骨髓,经免疫磁珠系统分离出CD 34细胞,体外扩增并向血管内皮细胞诱导分化;建立犬双下肢缺血动物模型,将诱导分化细胞移植入一侧缺血肢体中作为实验组,另一侧缺血肢体植入等体积的生理盐水作为自体对照组.移植后6周,检测缺血肢体中新生血管的形成.结果:细胞移植后6周,动脉造影显示实验组缺血肢体侧枝循环增加,明显多于对照组.微血管密度检测实验组为(14±2.3)个/高倍镜视野,明显高于对照组(6±2.1)个/高倍镜视野(P<0.05).激光共聚焦显微镜证实缺血肢体中移植的自体骨髓干细胞参与了新生血管形成.结论:自体骨髓干细胞移植可以促进缺血肢体组织中的新生血管形成.     

缺氧诱导因子转染内皮祖细胞治疗大鼠缺血后肢

目的 使用缺氧诱导因子-1α(HIF-1α)转染内皮祖细胞(EPC)治疗大鼠后肢缺血,观察EPC、HIF-1α转染EPC对大鼠缺血后肢血管新生和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的HIF-1α基因真核表达载体转染入EPCs后通过尾静脉注射入大鼠体内,并与注射磷酸盐缓冲液(PBS)或EPC的大鼠进行比较,观察转染HIF-1α对新生血管形成的影响.结果 (1)EPC组、HIF组较PBS组肢体恢复率明显增加(P<0.05),EPC组肢体恢复率较HIF组差(P<0.05).(2)与PBS组比较,各时间点中EPC、HIF组微血管密度(MVD)均明显增多(P<0.05),HIF组较EPC组明显增高(P<0.05).(3)HIF组的HIF与血管内皮生长因子(VEGF)蛋白表达较PBS组、EPC组明显增多(P<0.05).PBS组Capase-3的表达较EPC组、HIF组明显增多(P<0.05).(4)术后7 d,各组的大鼠肢体灌注均明显降低,但EPC、HIF组细胞的血流灌注较PBS组多(P<0.01).术后14、21 d,与PBS对照组比较,HIF组的血流灌注恢复明显(P<0.01),EPC组血流灌注较HIF组少(P<0.05).结论 EPCs对大鼠缺血后肢的局部血管新生有明显促进作用,联合应用HIF-1α和EPCs有更优的治疗效果.     

再次TURP患者前列腺组织微血管密度、血管内皮生长因子和雄激素受体的表达及意义

目的 探讨再次TURP患者前列腺组织微血管密度(MVD)、血管内皮生长因子(VEGF)和雄激素受体(AR)表达的临床意义.方法 再次TURP手术患者50例.选取2次手术标本(再次TURP组),50例首次手术患者标本作为对照组.采用免疫组织化学S-P法检测标本组织中CD_(34)、VEGF、AR的表达,通过血管内皮特异的CD_(34)染色计数MVD值.统计学比较3组标本MVD、VEGF、AR的表达水平.结果 再次TURP组1、2次手术标本和对照组标本MVD值分别为35.83±20.92、32.16±16.65和20.56±6.99,VEGF阳性表达率分别为82.0%(41例)、84.0%(42例)和60.0%(30例),AR阳性表达率分别为84.0%(42例)、88.0%(44例)和64.0%(32例),再次TURP组首次标本MVD值、AR及VEGF阳性表达率均高于对照组,差异有统计学意义(P<0.05);再次TURP组2次手术标本间各指标差异无统计学意义(P>0.05). 结论 BPH患者前列腺组织中高MVD值及AR、VEGF高表达是导致TURP术后复发及再次手术的重要原因之一.     

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.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

The multiply injured child

Blunt trauma is the principal cause of childhood death in many developed countries. This review outlines the differences between adults and children with respect to resuscitation and treatment of orthopaedic injuries in a child with polytrauma. Recent advances in techniques of fracture stabilization are reported.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

Utilisation des médicaments prokinétiques en réanimation : indications et limites ?

Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.