复方胰岛素凝胶剂促进大鼠皮肤溃疡愈合的初步研究

目的:研究复方胰岛素凝胶剂对大鼠皮肤溃疡的促愈合作用,并探讨其可能的作用机制。方法:18只Wistar大鼠背部各制备4个皮肤溃疡模型,共复制溃疡72个,随机将溃疡分为复方胰岛素凝胶治疗组(A组)、凝胶基质对照组(B组)、空白对照组(C组)。以治疗后不同时间点各组溃疡面积、溃疡愈合速度及组织病理学检查评价修复效果。结果:在伤后头10天内,A组溃疡缩小最明显,愈合速度明显快于B组、C组。伤后14天,A组溃疡基本愈合,皮肤结构完整、上皮化较厚;而B、C组溃疡仍未完全愈合,皮肤结构不完整、上皮化较薄。结论:局部应用复方胰岛素凝胶剂对大鼠皮肤溃疡有促愈合作用。     

局部应用NGF-胰岛素复合凝胶对糖尿病大鼠深Ⅱ度烫伤创面修复的影响

目的制备NGF-胰岛素复合凝胶并观察其对大鼠深Ⅱ度烫伤创面愈合的影响。方法以卡波姆980为基质,分别加入NGF 4 000 U、胰岛素800 U,制备胰岛素凝胶、NGF凝胶、NGF-胰岛素复合凝胶。观察NGF-胰岛素复合凝胶性状,并行体外药物释放检测。75只SPF级雄性Wistar大鼠,体重200～250 g,随机分为正常对照组(A组)、糖尿病对照组(B组)、局部胰岛素凝胶治疗组(C组)、局部NGF凝胶治疗组(D组)、局部NGF-胰岛素复合凝胶治疗组(E组),每组15只。B、C、D、E组大鼠采用一次性腹腔注射链脲佐菌素(55 mg/kg)制备1型糖尿病模型,A组注射相同剂量柠檬酸钠缓冲液。造模成功后,采用恒温水浴箱法于各组大鼠背部制备深Ⅱ度烫伤模型。A、B组创面外敷空白凝胶基质,C、D、E组对应外敷胰岛素凝胶、NGF凝胶、NGF-胰岛素复合凝胶,每天换药1次。烫伤后观察各组大鼠存活情况,于3、7、11、15、21 d观察创面愈合情况并计算创面愈合率,各时间点每组处死3只大鼠取皮肤全层标本行组织学及免疫组织化学染色观察。结果制备的NGF-胰岛素复合凝胶清亮透明,保湿性及黏附性良好,易于涂抹及清洗。体外释放检测示NGF-胰岛素复合凝胶释药时间可达24 h以上,且30 d内稳定性良好。各组大鼠均存活至实验完成。烫伤后3 d各组创面无缩小,7、11、15、21 d时E组创面愈合率最高,B组最低,与其余各组比较以及E、B组间比较,差异均有统计学意义(P<0.05)。组织学观察示各时间点E组肉芽组织和胶原纤维生长均优于其余各组。免疫组织化学染色示各组CD34、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)均于3 d开始表达,且随时间延长阳性细胞逐渐增多;各时间点E组微血管密度及PCNA最高,B组最低,与其余各组比较以及E、B组间比较差异均有统计学意义(P<0.05)。结论局部应用NGF-胰岛素复合凝胶可显著促进大鼠深Ⅱ度烫伤创面愈合。     

伤口愈合水凝胶治疗慢性下肢静脉曲张性溃疡的早期结果

目的 评价伤口愈合水凝胶(商品名奇特生)治疗下肢静脉曲张性溃疡的早期疗效,为治疗下肢静脉曲张性溃疡提供新方法.方法 2007年4-月2007年9月,门诊治疗60例临床分级均为C6级的慢性下肢静脉曲张性溃疡患者,随机分为伤口愈合水凝胶组(A组)和对照组(B组),每组30例.A组男24例,女6例;年龄(57.3±6.8)岁,病程(2.9±0.7)年,溃疡面积(3.4±0.6)cm2.B组男20例,女10例;年龄(60.1±7.4)岁,病程(3.3±0.9)年,溃疡面积(3.1±0.4)cm2.两组差异均无统计学意义(P＞0.05).A组用1mL/cm2伤口愈合水凝胶涂抹于创面,B组用生理盐水纱条覆盖创面治疗.治疗后每周测定两组溃疡面积,治疗15 d评定疗效至溃疡痊愈.结果 A组治疗7 d及14 d溃疡面积分别为(2.6±0.7)及(1.1±0.2)cm2;B组分别为(2.8±0.6)及(2.3±0.7)cm2.两组治疗7d差异无统计学意义(P＞0.05),治疗14 d差异有统计学意义(P＜0.05).A组溃疡愈合时间为(12.0±1.7)d,B组为(31.0±2.9)d,差异有统计学意义(P＜0.01).根据自定评价标准A组治愈16例,显效9例,有效4例,无效1例;B组治愈3例,显效9例,有效14例,无效4例.两组疗效比较,差异有统计学意义(P＜0.01). 结论 伤口愈合水凝胶可有效治疗下肢静脉曲张性溃疡.     

局部应用胰岛素对烫伤大鼠创面愈合的影响

目的观察局部应用小剂量胰岛素对烫伤大鼠创面愈合的影响,探讨其可能的作用机制.方法制作深Ⅱ度烫伤大鼠模型.部分大鼠创面下浸润注射0.1、1.0 U胰岛素,分别设为B、C组;以创面下浸润注射等渗盐水(A组)和腹部皮下注射0.1 U胰岛素(D组)的烫伤大鼠作为对照.记录各组创面愈合时间,伤后3 d起隔日计算A、B、C组的创面愈合百分率.观察各组创面愈合后的组织形态学改变,采用流式细胞仪对各组创面表皮细胞进行细胞周期分析,并测定血糖浓度的变化. 结果A、B、C、D组创面愈合时间分别为(24.57±5.19)、(18.36±4.12)、(21.46±2.97)、(24.50±1.05)d,B组较其他3组明显缩短(P<0.01).伤后5、9、11、13、15、17、19 d B组创面愈合率均明显高于A组,且伤后17 d时明显高于C组(P<0.05～0.01).组织形态学观察可见A组表皮层薄,钉脚数量少,真皮层内多见纤维细胞;B、C组表皮层增厚,钉脚数量多,真皮层内多见成纤维细胞.B组伤后4 d S期细胞比例明显高于A组(P<0.01);B组伤后4、5 d G2-M期细胞比例均明显高于A、C组(P<0.05～0.01).烫伤后24 h A组血糖波动在3.42～4.62 mmol/L;B组血糖变化规律与A组相似;C、D组注射后1 h血糖明显降低(P<0.01),注射后4 h逐渐恢复正常.结论局部应用小剂量胰岛素能明显地促进烫伤大鼠创面愈合,胰岛素可加速修复细胞的增殖分裂可能是其作用机制之一.     

复方中药软膏在猪断层皮创面愈合中的作用研究

目的:研究复方中药软膏在猪断层皮创面愈合中的作用。方法:制备猪断层皮创面模型,创面深度至真皮深层,深度达真皮厚度约3/4。实验分为复方中药软膏组(A组)、斯丽凯纳米银抗菌凝胶组(B组),空白对照组(C组),创面分别用复方中药软膏、斯丽凯纳米银抗菌凝胶、生理盐水纱布覆盖,创面定量涂抹上述药物。每天一次观察三组创面的愈合时间及不同时间点愈合情况。伤后每隔5天取上述三组创面组织,测定猪皮肤转化生长因子β(TGF-β)含量、过氧化氢酶(SOD)、丙二醛(MDA),并取创面组织行HE染色,观察表皮及真皮变化。结果:1动物实验显示,A组、B组、C组,愈合时间依次为(13.17±1.75)天、(18.42±1.93)天、(24.67±2.64)天,P0.05;2各组创面TGF-β含量的比较,在伤后第5天,A组(196.36±1.53)pg/ml、B组(160.52±1.43)pg/ml、C组(150.65±3.60)pg/ml,A组高于B组和C组,P0.05;伤后第9天比较,A组(183.39±1.73)pg/ml、B组(157.19±3.58)pg/ml、C组166.68±6.50,A组高于B组和C组,P0.05;其它时间点A组低于B组和C组;3各组创面中SOD含量的比较,伤后第5、第9、第14,A组高于B组和C组,P0.05;伤前一天和伤后第29天,P0.05;4各组创面中MDA含量的比较,在伤后第5至第24天,A组低于B组和C组,P0.05;伤前一天和伤后第29天,P0.05。结论:制备猪断层皮缺损创面模型可靠稳定复方中药软膏在猪断层皮创面愈合过程中,可缩短创面愈合时间,提高创面愈合速率,升高创面组织中TGF-β含量,促进创面愈合复方中药软膏可提高创面组织中SOD含量,加强药物抗氧化能力;降低创面组织中MDA含量,减轻细胞毒性损伤。可减轻皮肤损伤造成的局部或全身炎症反应,发挥抗炎作用.复方中药软膏减少创面组织中渗出液,体现抗渗出功能。     

不同时期应用复方肝素钠尿囊素凝胶对大鼠深Ⅱ度烧伤后增生性瘢痕形成的影响

目的：研究不同时期应用复方肝素钠尿囊素凝胶对深Ⅱ度烧伤大鼠增生性瘢痕(Hypertrophic scar,HS)的影响，以期发现复方肝素钠尿囊素凝胶抑制瘢痕的最佳时间。方法：使用砝码法制备深Ⅱ度烧伤大鼠模型。根据复方肝素钠尿囊素凝胶应用时间分为14 d组（A组）、28 d组（B组）和42 d组（C组），每组根据有无应用复方肝素钠尿囊素凝胶分为未应用组（A1组、B1组、C1组）和应用组（A2组、B2组、C2组），并于应用28 d后取材，每组应用前取材作为应用前对照组（A0组、B0组、C0组）。共造模45只，每小组5只。每天固定时间均匀涂抹复方肝素钠尿囊素凝胶于各创面。对A组创面拍照并计算创面愈合率，HE染色检测各组瘢痕组织的厚度，Masson染色检测各组瘢痕组织胶原纤维的表达，RT-PCR检测各组瘢痕组织炎症因子IL-6和TNF-α mRNA的表达。结果：应用复方肝素钠尿囊素凝对创面愈合率有一定影响。A2、B2组瘢痕组织的厚度增长量较A1、B1组低，未应用组和应用组瘢痕组织厚度的差值A组、B组均大于C组,差异有统计学意义（P<0.05）。A2、B2、C2组胶原纤维光密度值的增长量较...     

自体富血小板血浆局部注射治疗糖尿病足溃疡的临床研究

目的探讨局部注射自体富血小板血浆(platelet-rich plasma,PRP)治疗糖尿病足溃疡的疗效。方法将2017年10月—2018年10月收治且符合选择标准的90例糖尿病足溃疡患者随机分为3组:PRP注射组(A组,创面及创周局部注射PRP+水凝胶敷料覆盖创面)、PRP覆盖组(B组,PRP凝胶+水凝胶敷料覆盖创面)和对照组(C组,单纯水凝胶敷料覆盖创面),每组30例。3组患者性别、年龄、侧别、病程及术前糖化血红蛋白、创面面积、Wagner分级等一般资料比较,差异均无统计学意义(P0.05),具有可比性。比较3组患者治疗次数、住院时间及A、B组PRP使用总量。治疗期间观察创面愈合情况,首次清创术后3个月测算创面愈合率。结果 A、B、C组治疗次数分别为(10.2±0.8)、(11.4±0.6)、(12.5±0.5)次,A、B组PRP使用总量分别为(306±24)、(342±18)m L,组间比较差异均无统计学意义(P0.05)。A、B、C组住院时间分别为(40.5±1.8)、(62.1±2.3)、(88.6±1.4)d,差异有统计学意义(P0.05)。治疗过程中,3组创面坏死渗出均逐渐减少,创面面积逐渐缩小;A组均明显优于B、C组,B组优于C组。首次清创术后3个月,A、B、C组创面愈合率分别为93.2%±0.8%、52.1%±1.1%、21.3%±1.3%,组间比较差异均有统计学意义(P0.05)。结论 PRP能有效促进糖尿病足溃疡创面修复,而且PRP局部注射疗效优于PRP凝胶覆盖。     

自体表皮细胞悬液移植修复全层皮肤缺损创面的动物实验研究

目的探讨自体表皮细胞悬液移植技术用于全层皮肤缺损创面修复的适宜密度。方法取健康清洁级成年SD大鼠40只,雌雄不限,体质量210~230 g;根据细胞移植密度不同,随机分为高、中、低细胞密度及空白组(分别为A、B、C、D组,n=10)。取大鼠背部皮肤培养表皮细胞,并制作大鼠全层皮肤缺损创面抗挛缩模型。其中A、B、C组分别将0.2 mL密度为1×10~6、1×10~5、1×10~4个/cm~2的自体表皮细胞悬液移植至创面处,D组给予等量限制性角质形成细胞无血清培养基;取成年Wistar大鼠背部皮肤制备同种异体皮,覆盖各组创面。术后观察大鼠存活情况,于术后7、14、21 d大体观察同种异体皮成活、脱落及创面愈合情况,同种异体皮脱落后计算创面愈合率;21 d时取材行组织学及免疫组织化学染色,观察创面修复情况。结果术后大鼠均存活至实验完成。各组大鼠同种异体皮随时间延长逐渐成活,干燥并开始脱痂;至21 d同种异体皮基本脱落后A、B组创面可见成片上皮,C组创面可见少量菲薄上皮,D组创面无上皮形成。术后21 d同种异体皮脱落后,A、B、C、D组创面愈合率分别为62.9%±9.6%、64.2%±9.1%、38.5%±5.7%、22.7%±5.5%,A、B组创面愈合率显著高于C、D组(P0.05),C组高于D组(P0.05),A、B组间比较差异无统计学意义(P0.05)。组织学观察示,A、B、C组愈合的创面上皮层可见鳞状上皮细胞,A、B组表皮分层明显,C组表皮层薄、可见炎性细胞浸润,D组为肉芽组织。免疫组织化学染色观察示,A、B、C组表皮-真皮连接层Ⅳ型胶原和Ⅶ型胶原表达呈阳性,D组无表皮层呈阴性;A、B组Ⅳ、Ⅶ型胶原表达阳性细胞百分比显著高于C组(P0.05),A、B组间比较差异无统计学意义(P0.05)。结论自体表皮细胞悬液移植技术在大鼠全层皮肤缺损创面修复中可重构皮肤,1.0×10~5个/mL为创面修复的适宜移植密度。     

脂肪间充质干细胞-壳聚糖凝胶复合物治疗大鼠深Ⅱ度烫伤创面实验研究

目的制备脂肪间充质干细胞(adipose-derived stem cells,ADSCs)与温敏氯化壳聚糖(chitosan chloride,CSCl)凝胶复合物,研究其生物相容性及对大鼠深Ⅱ度烫伤创面修复的可行性。方法取SPF级6周龄雄性SD大鼠皮下脂肪组织,采用酶原消化并差速贴壁法制备ADSCs。将CSCl、β-甘油磷酸钠和羟乙基纤维素按8∶2∶2.5比例混合,制作温敏CSCl凝胶;采用Live/Dead染色和细胞计数试剂盒8(cell counting kit 8,CCK-8)法观察ADSCs在其中的存活和增殖情况。取SPF级8周龄雄性SD大鼠72只,采用开水接触烫伤法制备深Ⅱ度烫伤创面模型,随机分为3组,每组24只,A组为空白对照组,B组用温敏CSCl凝胶涂抹创面,C组用ADSCs/温敏CSCl凝胶复合物涂抹创面。术后3、7、14、21 d观察创面闭合情况并计算创面闭合率;术后7 d行HE染色观察炎性细胞数,21 d行HE染色观察新生表皮厚度;同时于术后7 d行CD31免疫组织化学染色观察新生微血管情况。结果 CSCl有温度敏感性,4℃为液态,37℃时成凝胶。Live/Dead染色和CCK-8法结果显示ADSCs在温敏CSCl凝胶中存活并持续增殖。大体观察示,术后各时间点C组创面闭合率均高于A、B组(P0.05)。HE染色示,术后7 d,3组大鼠创面修复进入纤维增生期,各组可见胶原沉积,真皮层可见炎性细胞浸润,C组炎性细胞数显著小于A、B组,B组小于A组(P0.01)。术后21 d,B、C组新生上皮及真皮层纤维结缔组织排列整齐,可见成纤维细胞及新生毛细血管;A组亦可见新生表皮覆盖,但真皮层纤维结缔组织排列较紊乱,见零星毛细血管。C组新生表皮厚度显著大于A、B组,B组大于A组(P0.01)。术后7 d,CD31免疫组织化学染色示各组均可见新生微血管,C组大鼠创面新生微血管数显著高于A、B组,B组高于A组(P0.05)。结论 ADSCs/温敏CSCl凝胶复合物具有良好的组织相容性,并且能加快大鼠深Ⅱ度烫伤创面修复。     

改性聚乳酸-Ⅰ型胶原荷载骨髓间充质干细胞对糖尿病大鼠创面愈合的影响

目的 观察改性聚乳酸-Ⅰ型胶原荷载骨髓间充质干细胞(BMSCs)对糖尿病大鼠创面愈合的影响.方法 36只糖尿病大鼠,随机分为3组:A组:改性聚乳酸-Ⅰ型胶原+BMSCs实验组;B组:改性聚乳酸-Ⅰ型胶原支架对照组;C组:空白对照组,观察创面愈合及5-溴脱氧尿嘧啶核苷(5-BrdU)阳性细胞角蛋白的表达.结果 A组第3、5、7、14天的创面愈合率分别为(18.20±2.68)％、(30.60±5.50)％、(57.63±9.13)％、(87.35±5.83)％,明显快于B、C组(P＜0.05),A组新生表皮较厚,新生血管及皮肤附属器多于B、C组,免疫组织化学法检测5 -BrdU阳性细胞角蛋白的表达.结论 改性聚乳酸-Ⅰ型胶原荷载BMSCs能促进糖尿病创面的愈合.     

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 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.     

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.     

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.     

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.