bFGF壳聚糖微球的制备及检测

目的探讨以壳聚糖为载体、采用乳化交联法制备的bFGF壳聚糖微球体外释放特性,为下一步实验奠定基础。方法应用0.6%三聚磷酸钠溶液作为交联剂,1.5%壳聚糖溶液作为载体,采用乳化交联法制备bFGF壳聚糖微球。激光粒度及Zeta电位分析仪检测微球粒径分布,扫描电镜观察形态;ELISA法计算bFGF壳聚糖微球载药量、包封率及体外释药规律。结果 bFGF壳聚糖微球粒径为20.312～24.152μm;扫描电镜观察显示微球表面光滑圆整,无明显孔隙,分布均匀,分散性好。载药量和包封率分别为(7.57±0.34)mg/g及95.14%±1.58%。bFGF壳聚糖微球可持续体外释放bFGF 24 d;bFGF浓度随时间延长逐渐升高,第24天达(820.45±21.34)ng/mL;微球体外释药具有突释效应,突释率为18.08%,24 d累计释放率为82.05%。结论乳化交联法制备bFGF壳聚糖微球操作简便,微球表面光滑、分布均匀,分散性好,载药量和包封率均较高,体外释药较稳定且释放率较高,是一种较理想的制备bFGF壳聚糖微球的方法。     

京尼平与戊二醛交联明胶微球的性能比较

目的 比较京尼平(genipin,GP)及戊二醛(glutaraldehyde,GA)交联明胶微球的性能,探讨GP交联明胶微球的优缺点.方法 以改进的双相乳化冷凝聚合法制备明胶微球,分别以GP、GA进行交联.取60%交联度的GP及GA明胶微球,分散于PBS中,比较其粒径外观、溶胀及降解性能.两种交联明胶微球分别携载rhBMP-2,测定载药量及包封率,观察10 d内的药物缓释性能.收集GP及GA明胶微球浸提液,倍比稀释成100%、50%、25%浓度,分别与小鼠成骨细胞共培养2 d,以DMEM组为阴性对照组,MTT法检测细胞增殖,测定GP及GA微球的细胞毒性.结果 GP及GA交联明胶微球在溶液中均呈规则圆形,粒径分别为(78±18)、(65±10)μm,GP交联明胶微球分散性更佳.当交联度均为60%时,GP交联明胶微球溶胀率为89.0%±4.8%,显著低于GA交联明胶微球(118.0%±7.6%),差异有统计学意义(P<0.01);GP及GA交联明胶微球分别于28、21 d完全降解,两者比较差异有统计学意义(P<0.05).GP及GA交联明胶微球载药量分别为(921±73)、(965±62)ng/g,包封率分别为88.5%±2.1%、89.7%±1.8%,两者比较差异均无统计学意义(P>0.05).GP及GA交联明胶微球10 d累积释药百分率分别为78.80%±4.96%、90.50%±5.12%,两者比较差异有统计学意义(P<0.05).当浸提液浓度为25%、50%、100%时,GP交联明胶微球细胞毒性均为Ⅰ级,GA交联明胶微球细胞毒性分别为Ⅱ、Ⅲ、Ⅲ级.结论 与GA交联明胶微球比较,GP交联明胶微球的综合性能更优越,可应用于组织工程领域.     

rh-BMP-2壳聚糖微球的制备及体外检测

[目的]以壳聚糖为辅料,通过乳化交联法制备新型重组人骨形态发生蛋白-2缓释微球,并对其粒径、载药、体外释药、理化特性及降解特性进行检测,以评估应用生物可降解的壳聚糖微球作为BMP-2缓释载体的可行性.[方法]以京尼平作为交联剂,应用乳化交联法制备具有控制释放功能的负载rhBMP-2壳聚糖微球,应用扫描电镜观察微球的形态和粒径;利用酶联免疫吸附实验(ELISA)动态检测BMP-2壳聚糖微球的载药率、包封率和缓释规律以分析微球的缓释能力.[结果]乳化交联法制备的壳聚糖微球,球形良好,球体表面光滑,具有较高的包封率(>85%).体外药物释放试验表明,rhBMP-2可以从壳聚糖微球中缓慢释放,整个释放过程可达30 d.[结论]应用乳化交联法制备的负载rhBMP-2壳聚糖缓释微球,具有很好的控制释放rhBMP-2的能力.这种新型药物控制释放系统在细胞因子的控制释放及骨组织工程中有潜在的应用价值.     

软组织填充材料聚氨酯微球的制备及体外生物相容性研究

目的制备生物医用聚氨酯微球,对其理化性能及体外生物相容性进行评价。方法采用自乳化法(乳化速率分别为1 000、2 000、3 000、4 000 r/min)制备聚氨酯微球,采用傅里叶变换红外光谱仪测试聚氨酯微球的分子结构,扫描电镜观察微球内部结构及表面形貌,筛选最佳乳化速率制备的微球进行后续实验。培养人脐静脉内皮细胞(human umbilical vein endoth elial cells,HUVECs),采用钙黄绿素/碘化丙啶(calceinacetoxymethylester/pyridine iodide,Calcein-AM/PI)双染观察细胞在聚氨酯材料上的形态及生长黏附情况。分别用含1%苯酚、10%FBS的H-DMEM培养基(A组)、按GB/T 16886.12标准规定比例制备的聚氨酯材料浸提液(B组)、含10%FBS的H-DMEM培养基(C组)培养细胞,采用细胞计数试剂盒8(cell counting kit 8,CCK-8)法评价细胞活力;通过溶血实验评价血液相容性,其中浸提液作为实验组,生理盐水作为阴性对照组,蒸馏水作为阳性对照组。结果扫描电镜观察示,乳化速率为2 000 r/min时制得的微球形态大小均较为理想,聚氨酯涂膜的表面为粗糙致密结构,内部为不均匀的多孔结构。Calcein-AM/PI双染观察示HUVECs与聚氨酯材料黏附紧密,且以绿染的活细胞为主。CCK-8检测示B、C组各时间点细胞增殖活力均显著高于A组(P0.05),材料细胞毒性低。溶血实验测定示,阳性对照组吸光度(A)值为0.864±0.002,阴性对照组A值为0.015±0.001,聚氨酯微球浸提液的溶血率为0.39%±0.07%(5%标准),无溶血作用。结论通过自乳化法成功制备了球形度较好的聚氨酯微球,该材料有利于细胞黏附增殖、细胞毒性低,且具备良好血液相容性,有望用作软组织缺损填充材料。     

rhBMP-2明胶纳米微球制备及体外缓释效果研究

目的制备重组人骨形态发生蛋白2(recombinant human bone morphogenetic protein-2,rhBMP-2)明胶纳米微球并检测其体外缓释效果。方法 "二次凝聚法"制备明胶纳米微球,扫描电镜、透射电镜和粒径分析仪检测纳米微球的表面形态、内部结构、粒径,计算其溶胀率;将rhBMP-2与明胶纳米微球复合,计算其包封率和载药量,并对其体外缓释效果进行检测。结果明胶纳米微球的表面形态良好,分散均一,内部结构多孔隙、通道,平均粒径(171.49±50.12)nm,溶胀率为1.83;rhBMP-2明胶纳米微球的包封率为(98.13±0.131)%,载药量为(58.89±0.079)ng/mg;rhBMP-2明胶纳米微球释药时间在1个月以上,呈"双相缓释",第1天为"突释相",释药量约为7%,以后平缓释放呈"缓释相",40%左右的药物于28 d内释放,约60%的药物在1个月以后释放。结论成功制备rhBMP-2明胶纳米微球,不但包封率高,而且体外缓释效果好。     

明胶微球/rhBMP-2/CPC的制备及其异位成骨效应研究

目的：制备多孔复合材料明胶微球／rhBMp-2／CPC并研究其异位成骨效应。方法：双相乳化冷凝聚合法制备明胶微球,京尼平进行交联,喷金后电镜观察。交联微球携载rhBMP-2,以2．5％的比例掺入磷酸钙骨水泥（calcium phosphate cements,CPC）固化,制成实验用多孔明胶微球／rhBMP-2／CPC,rhBMP-2／CPC作为对照组．两组材料固化后分别浸入生理盐水,1、3周后进行生物力学压缩实验,扫描电镜观察材料断面：ELISA法测定不同时间点生理盐水中rhBMP-2浓度,计算rhBMP-2的累积释放量。材料植入小鼠大腿肌袋,术后3周处死小鼠,切取材料及周围组织,HE染色后进行组织学观察,同时测定材料周围组织中碱性磷酸酶及钙含量。结果：交联的明胶微球呈规则圆形,粒径（62±18）um,分散性好。1、3周后实验组材料断面可见大量大孔形成,对照组未见明显大孔,实验组的总孔径率、大孔率及rhBMP-2的累积释放量均高于对照组：3周后实验组最大压缩强度（7．8±1．2）MPa,较对照组（11.2±1．6）MPa稍低。HE染色两组均可见软骨形成,但实验组更多,碱性磷酸酶及钙含量测定实验组分别为（4.33±0．52）IU／g和（6．12±1.22）ug／mg,高于对照组的（2．67±0．23）IU／g和（3．12±0．41）ug／mg。结论：明胶微球／rhBMp-2／CPC在微球降解后形成多孔磷酸钙复合材料,使rhBMp2的释放量增加,具有强大的异位成骨性能,是一种优秀的骨组织工程材料。     

重组人骨形态发生蛋白-2壳聚糖纳米微球的制备及检测

目的 制备负载重组人骨形态发生蛋白-2(rhBMP-2)壳聚糖纳米微球,并检测其粒径、形态、降解及药理特性,以评估壳聚糖纳米微球作为rhBMP-2缓释载体的可行性.方法 以壳聚糖为原料、三聚磷酸钠为交联剂,通过离子交联法制备负载rhBMP-2壳聚糖纳米微球,应用透视电镜观察微球的形态、激光粒径,分析其粒径分布、溶菌酶降解,了解降解特性.通过酶联免疫吸附实验(ELISA)检测rhBMP-2壳聚糖微球的载药率、包封率和释药规律.结果 离子交联法制备的壳聚糖纳米微球,平均粒径大小为230nm,成球性较好,包封率和载药率分别为(66.867±4.575)％、(33.437±2.290)μg/mg;体外释药试验rhBMP-2可以从壳聚糖纳米微球中缓慢释放,释放行为符合双向动力学规律,整个释放过程可达30 d.结论 离子交联法可成功制备壳聚糖纳米微球并具有缓释rhBMP-2的能力,为进一步应用于骨组织工程研究提供实验依据.     

聚乙二醇修饰磁性5-氟尿嘧啶白蛋白微球的制备与表征

目的 制备聚乙二醇(PEG)修饰的磁性5-氟尿嘧啶白蛋白微球(PEG-5-Fu-MAMS),对其表征和体外释放规律进行初步研究.方法 采用乳化-加热固化法,制备PEG修饰的磁性5-氟尿嘧啶白蛋白微球;用扫描电镜和Malvem粒度仪对其形貌和粒径进行表征;碱消化后在265 nm波长下测定吸光度计算载药量;溶解后于0、5、10、20、30、40、60、90 min测定其吸光度,研究其稳定性和磁响应性;药物体外释放实验研究微球的缓释性.结果 微球平均粒径为1.32μm,呈球形,表面光滑;载药量为(5.31±0.13)%;具有良好的磁响应性;0.5 h释放度为(28.50±0.66)%,24 h释放度为(46.93±2.83)%.结论 PEG-5-Fu-MAMS具有良好的外形、粒径、载药量、磁响应性和药物缓释作用.     

壳聚糖复合止血膜的制备及性能评价

目的为提高壳聚糖(chitosan,CS)/羧甲基壳聚糖(carboxymethyl chitosan,CMCS)止血膜柔韧性和止血性能,制备止血膜时引入甘油和酚磺乙胺。探讨甘油和酚磺乙胺对CS/CMCS止血膜力学性能的影响,评价改性后CS/CMCS止血膜的止血效果。方法将质量分数为2%的CS乙酸溶液及CMCS水溶液分别与10%、15%、20%、25%、30%的甘油水溶液,按体积比为16∶4∶5混合,或同时加入质量分数为0.5%的酚磺乙胺,采用溶液浇铸法分别制得不同甘油含量的甘油改性CS/CMCS止血膜和载药止血膜。检测甘油改性CS/CMCS止血膜pH值,测量其厚度。根据GB13022-1991中塑料薄膜拉伸性能试验方法测定不同甘油含量的甘油改性CS/CMCS止血膜拉伸强度、断裂伸长率和模量,并测量含水率。于4只新西兰兔耳背分别制备大小为1cm×1cm的20个静脉出血创面和5个动脉出血创面,分别将甘油含量为15%和25%的甘油改性CS/CMCS止血膜(A组及B组),以及相同甘油含量的甘油改性CS/CMCS载药止血膜(C组及D组)覆盖静脉出血创面(n=5),观察止血时间及失血量;选择止血性能最佳的止血膜覆盖动脉出血创面并观察止血效果。结果甘油改性CS/CMCS止血膜呈浅黄色,pH值为3～4,厚度为30～50μm。随甘油含量增加,甘油改性CS/CMCS止血膜拉伸强度和模量下降,与甘油含量为10%时比较,甘油含量≥15%时分别下降了7.6%～60.2%和97%～99%,但断裂伸长率和含水率分别增加5.7～11.6倍和13%～125%。大体观察见止血膜接触血液后即迅速黏附其上,并吸收血液中水分;止血膜即刻皱起,呈波浪状。A、B、C、D组处理静脉创面止血时间分别为(70±3)、(120±10)、(52±4)及(63±3)s,失血量为(117.2±10.8)、(121.2±8.3)、(98.8±5.5)及(90.3±7.1)mg。A、B组止血时间及失血量与C、D组比较,差异有统计学意义(P0.05)。取C组止血膜处理兔耳背动脉出血创面,出血时间和失血量分别为(123±10)s和(453.3±30.0)mg。结论甘油和酚磺乙胺复合改性增加了CS/CMCS止血膜的柔韧性,缩短了出血时间。     

负载重组人骨形态发生蛋白-2壳聚糖纳米微球的制备及异位成骨活性研究

目的 制备负载重组人骨形态发生蛋白-2(rhBMP-2)的壳聚糖纳米微球,并考察其成骨活性. 方法 应用离子交联法制备空白壳聚糖纳米微球和rhBMP-2壳聚糖纳米微球,应用透射电镜观察微球的形态,激光粒径分析仪测定其粒径的分布,检测其载药量、包封率及累积释药率.取24只SD大鼠,随机分为4组,每组6只.以无菌手术分别在大鼠左侧股部建立肌袋.A组大鼠肌袋内植入rhBMP-2壳聚糖纳米微球(含rhBMP-2 1 mg),B组大鼠肌袋内植入rhBMP-2 1 mg,C组大鼠肌袋内植入空白壳聚糖纳米微球,D组大鼠肌袋内不做任何处理.评估rhBMP-2壳聚糖纳米微球的成骨活性.结果离子交联法制备的壳聚糖纳米微球球形规整、分散均匀,微球平均粒径为230.0 nm,分布较集中,包封率为66.87％±4.58％,载药率为(33.44±2.29) μg/mg.A、B、C、D组的ALP活性平均分别为(1.94±0 35)、(1.48±0.56)、(0.20±0.07)及(0.18±0.06) kat/g,差异有统计学意义(F=42.959,P=0.000),A、B组明显高于C、D组,且A组高于B组.4组钙含量平均分别为(5.20±1.42)、(3.80±1.40)、(0.19±0.08)、(0.20±0.08)μg/mg,差异有统计学意义(F=39.242,P=0.000),A、B组明 显高于C、D组,且A组高于B组. 结论 离子交联法可成功制备出均一的rhBMP-2壳聚糖纳米微球,该微球具有良好的载药性能和缓释性能,且其骨诱导活性优于单纯rhBMP-2.     

980-nm Diode laser: a novel laser technology for vaporization of the prostate

OBJECTIVE: The wavelength 980 nm of a recently introduced diode laser system for treatment of benign prostatic enlargement offers a high simultaneous absorption in water and haemoglobin, and is postulated to combine high tissue ablative properties with a good haemostasis. METHODS: The Ceralas HPD150 diode laser system was evaluated in the well-established ex vivo model of the isolated blood-perfused porcine kidney to evaluate tissue ablation capacity and haemostatic properties at different generator settings. A histological examination of the ablated renal tissue followed. The results were compared with the reference standards transurethral resection of the prostate (TURP) and potassium-titanyl-phosphate (KTP) laser. RESULTS: The diode laser displays a higher tissue ablation capacity, reaching 7.24+/-1.48 g after 10 min, compared with the KTP laser (3.99+/-0.48 g; p<0.05), whereas only 30s are needed to resect the tissue in the same surface area using TURP, resulting in 8.28+/-0.38 g of tissue removal. With a bleeding rate of 0.14+/-0.07 g/min, the diode laser offers haemostatic properties equivalent to the KTP laser (0.21+/-0.07 g/min) and a significantly reduced bleeding compared with TURP (20.14+/-2.03 g/min; p<0.05). The corresponding depths of the coagulation zones are 290.1+/-46.9 microm for the diode laser, 666.9+/-64.0 microm for the KTP laser (p<0.05), and 287.1+/-27.5 microm for TURP. CONCLUSIONS: In the standardised ex vivo investigation, the 980-nm diode laser offers a higher tissue ablation capacity and similar haemostasis compared with the KTP laser. In comparison with TURP, both tissue ablation and bleeding are significantly reduced. The promising ex vivo results warrant further clinical investigation.     

Ex-vivo comparison of the haemostatic properties of standard transurethral resection and transurethral vaporization resection of the prostate

OBJECTIVE: To compare the haemostatic properties of standard transurethral resection of the prostate (TURP) and transurethral vaporization resection of the prostate (TUVRP), as perioperative bleeding is still regarded as the major complication of prostate resection. MATERIALS AND METHODS: Isolated blood-perfused porcine kidneys were used to determine the haemostatic efficacy of TURP and TUVRP (using two different electrodes). Bleeding was quantified precisely in relation to tissue ablation for the two techniques, and specimens were evaluated histologically. RESULTS: Both TUVRP groups had significantly less bleeding (P = 0.005) than the TURP group for a standardized ablation volume of perfused kidney tissue (18.9, 19.5 and 24.1 mL/min, respectively). The different TUVRP electrodes had no significant haemostatic differences. The histology showed significantly (P = 0.03) larger coagulation zones for the TUVRP groups than for standard TURP. CONCLUSIONS: TUVRP ex-vivo was associated with significantly better haemostasis than TURP. The haemostatic properties of different active electrodes for TUVRP seem to be equivalent.     

Haemostatic efficacy of an ethyl-2-cyanoacrylate-based aerosol in combination with tourniquet application in a large wound model with an arterial injury

BACKGROUND: Tourniquet application is the standard method for the control of severe trauma haemorrhage. However, it may result in severe ischaemic injuries when used for a long time. In this study, we developed a modified ethyl-2-cyanoacrylate-based aerosol (ECA) aerosol spray and determined its efficacy for short-time control of bleeding of large wounds in pigs when used in combination with tourniquet application. METHODS: A large wound model with a femoral arterial injury was made in the middle of either thigh of the pig. Thirty white female hybrid pigs were divided evenly and randomly into three groups, including tourniquet application only group (group A), tourniquet-ECA group (group B, a combination of ECA with tourniquet application) and tourniquet-ECA with wound cleaning group (group C, a combination of ECA with tourniquet application plus wound cleaning). RESULTS: The success rates of haemostasis were 0%, 30%and 90% in groups A, B and C, respectively (P<0.05). The incidence of haematoma and the membrane forming time were 100% and 20%, and 5.9+/-1.0min and 8.3+/-1.1min, respectively, in groups B and C (both P<0.05). The haemostatic time and the thickness of membrane were 11.9+/-1.8min and 10.2+/-1.4min, and 0.68+/-0.29mm and 0.79+/-0.25mm, respectively, in the two groups (P>0.05, both). CONCLUSION: The ECA spray achieves haemostasis within a very short time when it is used in combination with tourniquet application in a large wound model with an arterial injury. It may effectively prevent the wound from bleeding without the need for any long-term pressure bandage to wrap the wound, and it is easy to be disposed in debridement. Therefore, it may serve as an optimal choice for the first aid of large wounds with an arterial injury.     

Prospective comparison between total sternotomy and ministernotomy for aortic valve replacement

Ministernotomy (MS) is an alternative for total sternotomy (TS) in aortic valve replacement. We compared these two approaches for results and adverse effects in a prospective study. From January to December 2000, 100 patients who underwent aortic valve replacement were included in two groups of 50 according to the surgical approach that used MS or TS; one senior surgeon performed all cases in each group. Valvular pathologies were either stenosis or insufficiency. Mean age was 63 +/- 14 years in MS, 67 +/- 12 in TS (p = ns). NYHA class was 2.7 +/- 0.5 in MS, 2.8 +/- 0.6 in TS (p = ns). Left ventricular ejection fraction was 58 +/- 12% in MS, 57 +/- 12% in TS (p = ns). There was a significant difference between MS and TS in aortic cross-clamping (66 +/- 14 min vs 48 +/- 9 min) and cardiopulmonary bypass (88 +/- 18 min vs 69 +/- 10 min, p < 0.01), but not in intervention times (2.8 +/- 0.4 hours vs 2.7 +/- 0.4 hours). Mean intensive care stay was reduced in MS (1.7 +/- 1.6 days vs 2.6 +/- 6 days, p < 0.05). Intubation times (12 +/- 7 hours vs 14 +/- 9 hours), 24 hours bleeding (394 +/- 219 mL vs 465 +/- 318), reintervention for hemostasis (4% vs 2%), rhythmic complications (14% vs 14%), and mortality at 1 month (2% vs 2%) were comparable in MS and TS. In aortic valve surgery, ministernotomy is technically more demanding and needs more time. It is as safe and as effective as conventional sternotomy but its eventual benefits, excepting upon cosmesis, are still to be defined.     

Use of the harmonic scalpel versus conventional haemostatic techniques in patients with Grave disease undergoing total thyroidectomy: a prospective randomised controlled trial

INTRODUCTION: Thyrotoxicosis is often considered to be the most difficult thyroid operation because of the high vascularisation and the risk of bleeding. The conventional haemostatic technique in thyroidectomy today include knot tying and electrocoagulation. The introduction of the harmonic scalpel (HS) has led to further research if the use of the HS has any benefits in thyroid surgery. To our knowledge, no previous study has evaluated the HS dissection technique in a homogenous group of patients with Graves' disease undergoing total thyroidectomy. MATERIALS AND METHODS: Fifty-one patients (39 women and 12 men) with the pre-operative diagnosis of Graves' disease treated at two endocrine centers were randomised to total thyroidectomy with the use of the HS or with conventional haemostatic techniques. RESULTS: Twenty-seven patients were randomised to the harmonic group and 24 to the conventional group. The operating time was shorter in the HS group (median, 121 min; range, 84-213 min) compared to the conventional group (median, 172 min; range, 66-268 min; p = 0.011). CONCLUSION: The use of the HS was associated with a significant reduction in operating time compared to the use of the conventional haemostatic techniques in patients with Graves' disease undergoing total thyroidectomy.     

A comparison of the haemostatic effect of Vivostat patient-derived fibrin sealant with oxidised cellulose (Surgicel) in multiple surgical procedures

AIM: To evaluate the haemostatic properties of Vivostat patient-derived fibrin sealant in a broad range of surgical procedures. METHOD: In a prospective, randomised, multicentre, clinical study, typical surgical wounds of 69 patients (cardiothoracic, general, obstetric and gynaecologic, and vascular), requiring intervention to control bleeding, were treated with either Vivostat-derived sealant (n = 35) or Surgicel (n = 34) as required and the time taken to arrest bleeding was assessed. RESULTS: Compared with Surgicel, the mean time to haemostasis of Vivostat-derived sealant was significantly shorter (1.6 vs. 3.3 min, p < 0.0001) and more patients were successfully treated (i.e. no additional haemostatic measures required; 94 vs. 65%, p = 0.003). CONCLUSION: Vivostat-derived sealant is a more reliable and rapidly effective surgical haemostat than Surgicel.     

The role of recombinant factor VIIa in the treatment of life-threatening haemorrhage in blunt trauma

BACKGROUND: Recombinant factor VIIa (rFVIIa) is a novel haemostatic agent originally developed to treat bleeding in haemophiliacs. Several case reports suggest effectiveness of rFVIIa in the treatment of patients without pre-existing bleeding disorders. The aim of this study is to evaluate treatment with recombinant (rFVIIa) in blunt trauma patients with uncontrolled bleeding. PATIENTS AND METHODS: This study was designed as a retrospective case review. Consecutive patients with life-threatening uncontrolled bleeding due to blunt trauma who were treated with rFVIIa were selected. Data were obtained from medical records. RESULTS: A total of eight blunt trauma patients were treated with rFVIIa for uncontrolled bleeding. After treatment the need for transfusion of red blood cells (RBC) decreased significantly from 31.3 +/- 15.8 to 6.1 +/- 6.8 units (P = 0.003), fresh frozen plasma (FFP) from 13.3 +/- 6.6 to 5 +/- 6.3 units (P = 0.02), and platelets from 3.6 +/- 1.8 to 1.5 +/- 2.3 units (P = 0.01). Three patients died of non-bleeding complications. The other five fully recovered. CONCLUSION: Treatment with rFVIIa reduced or stopped bleeding in all patients. No adverse events were registered. Prospective studies are mandatory to elucidate the role of rFVIIa in blunt trauma.     

Improved efficacy of basiliximab over antilymphocyte globulin induction therapy in paediatric renal transplantation.

BACKGROUND: Basiliximab is a chimeric human/mouse monoclonal antibody directed against the alpha chain of the IL-2 receptor, CD25, which has been reported as successfully reducing rejection in adult renal transplant recipients. Reported clinical experience of basiliximab in paediatric renal transplantation is limited. METHODS: Using two intravenous doses on day 0 (pre-operatively) and day 4 with prednisolone and cyclosporin A (dual) maintenance immunosuppression in 42 children undergoing renal transplantation in our unit (SIM group), we have compared patient and graft outcome, rejection rates in the first 6 months, renal function and the incidence of Cytomegalovirus (CMV) infection with 42 consecutive children who previously received antilymphocyte globulin immunoprophylaxis with prednisolone, cyclosporin A and azathioprine (triple) maintenance immunosuppression (ALG group). The two groups were similar, including HLA mismatching, apart from age and size at transplantation (SIM=10.3+/-5.4 years vs ALG=12.4+/-4.2 years, P<0.05). RESULTS: One patient in the SIM group died from food inhalation with a functioning kidney and one patient in the ALG group from Pneumocystis pneumonia and post-transplant lymphoproliferative disorders with a rejecting graft. Both 1- and 2-year actuarial graft survivals were 93% for the SIM group and 86% for the ALG group (NS). Three grafts were lost in the SIM group-none from rejection (thrombosis 2, death 1)-and seven in the ALG group-three from rejection. Occurrence of biopsy documented rejection in the first 6 months after transplantation was 0.15+/-0.22 for the SIM group and 0.35+/-0.51 episodes per pt-month at risk for ALG treatment (P<0.04). Early rejection within 30 post-operative days occurred in only four SIM patients, three of whom had undergone retransplantation. Forty-seven per cent of rejection episodes occurred between days 30 and 44 in SIM treated patients. Switching to tacrolimus was similar in both groups; 24% of the SIM groups were prescribed triple therapy. Estimated glomerular filtration rate was 46.0 and 46.2 ml/min for SIM and ALG groups, respectively, six months after transplantation. Ten per cent of SIM and 19% of ALG treated patients developed clinically significant CMV infection (NS) but none of 16 (R(+)) SIM children had CMV infection compared with 8 out of 15 (R(+)) ALG patients (P<0.01). CONCLUSIONS: Basiliximab immunoprophylaxis and dual therapy reduces rejection episodes in the first six months and maintains graft survival and function after paediatric renal transplantation. Seventy-six per cent of children receiving basiliximab immunoprophylaxis were successfully maintained on long-term dual immunosuppression. This immunosuppressive protocol reduces CMV disease in CMV(+) recipients compared with ALG induction and triple therapy.     

Fibrinogen-impregnated collagen as a combined haemostatic agent and antibiotic delivery system in a porcine model of splenic trauma.

OBJECTIVE: To assess the effect of rifampicin on the haemostatic function of a fibrinogen-impregnated collagen fleece. DESIGN: Laboratory experiment. SETTING: Government research establishment, UK. MATERIAL: Six Large White pigs. INTERVENTIONS: Four 5 cm incisions were made in the spleen of each animal. Three of the wounds were each covered with a sheet of either dry, saline-soaked or rifampicin-soaked fibrinogen-impregnated collagen. MAIN OUTCOME MEASURES: The bleeding time and blood loss from each wound was recorded. Systemic serum rifampicin concentrations were measured using a Staphylococcus aureus inhibition assay. RESULTS: Dry fibrinogen-impregnated collagen resulted in significantly less blood loss (112 (21) compared with 39 (13)ml, p < 0.05) and shorter bleeding time (16 (2) compared with 9 (1) min, p < 0.01) than in untreated control wounds. Pre-soaking in saline or rifampicin solution had no significant effect on its haemostatic function. Rifampicin concentrations above the minimum inhibitory concentration were recorded in the systemic circulation 45 minutes after injury and persisted for the duration of the experiment. CONCLUSIONS: Fibrinogen-impregnated collagen is an effective haemostatic agent in splenic trauma that may be of use for both the local and systemic delivery of antibiotics.     

Differential platelet receptor expression following hydroxyethyl starch infusion in thrombocytopaenic orthotopic liver transplantation recipients

BACKGROUND AND OBJECTIVE: Platelet function abnormalities influence the haemostatic defect in patients with liver failure. Patients after orthotopic liver transplantation present thrombocytopaenia associated with bleeding problems, which may be aggravated by the interaction of hydroxyethyl starches with platelets. METHODS: From 12 patients after liver transplantation venous blood samples (3 mL) were taken before, 20 and 120 min after infusion of hydroxyethyl starch of medium molecular weight (200 kDa/0.5) 6% 10 mL kg(-1) over a period of 30 min. Surface expression of glycoprotein IIb/IIIa and P-selectin were quantified by flow cytometry as well as the percentage of platelet-leucocyte complexes. RESULTS: A significant decrease of P-selectin expression following administration of hydroxyethyl starch after 120 min (89.1 +/- 4.2%, P = 0.029) and a corresponding significant reduction in the formation of platelet-monocyte complexes (81.1 +/- 7.8%, P = 0.001) were observed. There was no alteration in the glycoprotein IIb/IIIa expression after hydroxyethyl starch infusion. CONCLUSIONS: Infusion of hydroxyethyl starch 200 kDa/0.5 in clinically relevant doses does not alter glycoprotein IIb/IIIa expression in thrombocytopaenic patients with pre-existing platelet dysfunction after orthotopic liver transplantation. Accordingly, infusion of hydroxyethyl starch may have a beneficial effect on microvascular graft perfusion through the resulting haemodilution and reduced P-selectin expression with subsequent reduced leucocyte-platelet complexes and endothelial adhesion.