Efficient inhibition of in-stent restenosis by controlled stent-based inhibition of elastase: a pilot study

PURPOSE: It is proposed that local elastase inhibition could suppress the extracellular matrix (ECM) degradation and subsequent smooth muscle cell migration and limit subsequent in-stent restenosis. This study evaluated the effect of stent-based controlled elastase inhibition on restenosis after stent implantation in a rabbit model. MATERIALS AND METHODS: Biodegradable microspheres containing the potent elastase inhibitor alpha-1-antitrypsin (AAT) were prepared. Daily release of AAT from the microspheres was confirmed in vitro. The microspheres were loaded into stents with an abluminal polymer reservoir. Implantation of the stent with AAT microspheres and blank microspheres (control) was performed in the abdominal aortae of six rabbits in each group. After stent deployment, all stents were overdilated to 125% diameter. Stent-implanted arteries were harvested after 7 days (n = 3 each) or 28 days (n = 3 each). To assess the effect of local delivery of AAT, elastase activity and elastin content of the stent-implanted aortae were analyzed. As an endpoint, intima-to-media (I/M) ratio was determined in the 7-day and 28-day specimens. RESULTS: Significant inhibition of elastase was confirmed in treated vessels versus controls at 7 days after stent implantation (P < .05). This reduction in elastase activity was sufficient to afford early and late reduction of in-stent neointima. Plaque progression in the 28-day specimens decreased to 67% with elastase inhibition relative to controls (P < .05). CONCLUSION: Stent-based controlled release of elastase inhibitor may significantly reduce ECM degradation and might limit in-stent restenosis.     

Effect of glucagon on blood glucose homeostasis in infants of diabetic mothers.

Thirty infants of diabetic mothers (IDM) were randomly selected and divided into 3 groups of 10 babies each. Group A were used as controls. Group B received glucagon 300 mug/kg i.m. and Group C received glucagon 300 mug/kg i.v. at birth. Hypoglycemia developed in 6 infants in Group A and 4 infants in Group B. None of the infants in Group C had hypoglycemia. Mean blood glucose was higher in Group C in the first 3 hours than Group A, and higher in Group B in the first (/2-1 hour. I.v. glucshon, 300 mug/kg when given in the first 15 minutes after birth prevented hypoglycemia in IDM in the first hours of life.     

Venous clots: evaluation with MR imaging

In vitro and in vivo studies were performed to determine the proton relaxation and imaging characteristics of static blood and acute and organized clot in canine jugular veins. In vivo, it was found that two inversion recovery sequences using a short inversion time (100 msec) demonstrated better differentiation of signal intensity of intravascular clot from surrounding soft tissues than did standard T1- and T2-weighted sequences. In vitro, quantitative measurements showed marked reduction of both T1 and T2 relaxation time of acute clot compared with stagnant blood. In addition, the T1 relaxation time, and to a lesser extent the T2 relaxation time, shortened as the clot aged, indicating a potential role for magnetic resonance imaging in determining the age of venous thrombi.     

ASRI2005-88 Comparable levels of CD4+CD25+ CTLA4+ Treg cells in peripheral blood of pre-eclampsia and normal pregnant patients

The acceptance of the semiallogeneic fetus within the maternal environment requires tolerance mechanisms not fully characterized yet. Normal pregnancy is known to be associated with a Th2 profile. Furthermore, T-regulatory cells were proposed to regulate the Th2/Th1 balance at early stages of pregnancy. Treg may avoid the shift to a Th1 profile preventing miscarriage. Accordingly, spontaneous abortion is characterized by a Th1 dominance and diminished levels of Tregulatory cells (Treg). The major aim of the present work was to investigate if pre-eclampsia, a late immunological complication of pregnancy, is characterized by similar hallmarks. Therefore, we measured the surface antigens CD4, CD25, CD8, CTLA4 (as well as the secretion of IL-10) in peripheral blood from patients suffering from pre-eclampsia (n = 8) and age-matched patients undergoing normal pregnancies (n = 9) by 4-colour flow-cytometry. We were not able to find any significant differences in the levels of CD4⁺, CD25⁺, CD8⁺, CTLA4, CD4⁺/CD25⁺, CD4⁺/CD25^bright, CD4⁺/CTLA4, CD25⁺/CTLA4, CD4⁺/CD25⁺/CTLA4, CD8⁺/CD25⁺, CD8⁺/CTLA4 or CD8⁺/CD25⁺/CTLA4 cell subsets. Our data suggest that Treg may not participate in the onset of pre-eclampsia and suggest other regulatory mechanisms during late pregnancy.     

Does transfusion using a syringe infusion pump and small-gauge needle cause hemolysis?

Hemolysis of two- and nine-day-stored sedimented red blood cells (hematocrit 65%), infused by a constant-rate syringe delivery pump through a 25-gauge needle was investigated. Fifteen-ml aliquots of blood were pumped through the system at flow rates of 10.6, 20.5, and 70 ml/hour. Plasma-free hemoglobin and potassium were measured and compared to controls. Significant red blood cell hemolysis occurred during passage through this infusion system, and the amount of hemolysis was greater with nine-day-stored cells. These cells showed more hemolysis with slower flow rates, but the two-day-stored cells were not affected by rate of flow.     

胶原-壳聚糖复合材料的制备及生物安全性检测

目的:制备胶原-壳聚糖复合细胞载体,并对该载体进行系统的生物学性能检测。方法:实验于2003-07/2006-06在天津市医药科学研究所完成。将胶原溶液和壳聚糖溶液按照一定比例(9∶1)混匀,交联后真空冷冻干燥,制成胶原-壳聚糖复合载体,对该载体进行复合材料性状及理化性能检测。并采用急性全身毒性试验、皮内刺激试验、皮肤致敏试验、溶血试验、细胞毒性试验和致突变试验进行生物学性能检测。结果:①胶原-壳聚糖复合材料具有三维立体多孔结构,适合细胞的三维生长,能为新生组织提供良好的支架。②急性全身毒性试验、皮内刺激试验均阴性,致敏率仅为6.25%,细胞毒性为0级,无诱变能力。结论:从仿生学角度出发,制备出可生物降解的胶原-壳聚糖复合材料,经过系统的生物学评价发现,胶原-壳聚糖复合材料具有良好的生物安全性,对机体无毒,不致突变,对细胞有较强的亲和作用,利于细胞生长和分化。     

三种移植物关节镜下重建膝关节前交叉韧带效果比较：2年随访

目的:采用自体骨-髌韧带、自体双股半腱肌腱半膜肌及同种异体跟腱移植重建膝关节前交叉韧带,比较不同移植物的临床疗效。方法:选择1998-06/2003-02中山大学附属第三医院骨科单纯前交叉韧带损伤后行关节镜下重建手术病例96例,患者均签署知情同意书。根据不同移植物分为3组:①自体骨-髌韧带组38例,应用自体中1/3骨-髌韧带-骨移植物。②自体双股半腱肌腱股薄肌腱组22例,应用自体双股半腱肌腱股薄肌腱。③同种异体跟腱组36例,应用同种异体跟腱。术后定期随访,对膝关节活动度、肌力恢复程度、Werner髌股痛评分(最差为0分,最高为55分)、Lysholm评分(0～100分,分数越高膝关节功能恢复越好)、国际膝关节文献委员会评分(按病情严重程度分类分为正常、接近正常、异常、严重异常4个等级)等进行对比观察。结果:①96例患者随访2年,无脱落。②全部患者无感染,未发生髌骨骨折。也未发现关节内粘连、下肢深静脉血栓形成和血管神经损伤等并发症。③膝关节活动度、肌力恢复情况、髌股痛评分:随访结束时3组差异均无显著性意义(P>0.05)。④Lysholm膝关节评分:随访结束时自体骨-髌韧带组由术前(68.2±6.3)分提高至(88.6±6.8)分,自体双股半腱肌腱股薄肌腱组由术前(66.5±6.5)分提高至(86.4±6.6)分,同种异体跟腱组由术前(68.2±6.3)分提高至(86.3±6.2)分,随访结束时各组评分均显著高于术前(P<0.05),3组比较差异无显著性意义(P>0.05)。⑤国际膝关节文献委员会评分(术后活动水平正常或接近正常):随访结束时自体骨-髌韧带组为87%,自体双股半腱肌腱股薄肌腱组为86%,同种异体跟腱组为89%,各组移植术后膝关节功能均有所改善,3组间差异无显著性意义(P>0.05)。结论:关节镜下采用自体骨-髌韧带、自体双股半腱肌腱股薄肌腱和同种异体跟腱移植重建前交叉韧带,均能明显改善膝关节运动功能,3种移植方法的临床疗效无明显差异,提示重建前交叉韧带的术后疗效与移植物种类的相关性不明显。     

无牙颌颞下颌关节紊乱病患者总义齿修复前后咬合垂直距离改变与髁状突在关节凹内位置的关系

目的:观察咬合垂直距离改变对无牙颌颞下颌关节紊乱病患者两侧颞颌关节髁状突位置的影响。方法:于1994-01/1997-12选择本院口腔修复门诊收治的无牙颌患者中符合颞下颌关节紊乱病诊断标准,同时垂直距离减低的患者48例。实验方案经医院伦理委员会审批,患者均知情同意。将48例无牙颌颞下颌关节紊乱病患者根据垂直距离减低程度的不同分为3组:减低1.8～6.0mm组18例,减低6.1～10.0mm组20例,减低10.1￣14.0mm组10例。通过重新制作一副全口义齿的方法治疗,咬合垂直距离恢复在合适的范围内,3组全口义齿的咬合垂直距离恢复前分别平均为63.4,60.6,54.2mm,恢复后咬合垂直距离分别平均为67.8,68.4,66.4mm,平均抬高4.4,7.8,12.2mm。通过拍摄正中颌位时颞下颌关节薛氏位X射线片测量各组前、后、上关节间隙。结果:垂直距离恢复前,减低1.8～6.0mm组关节后间隙,减低6.1～10.0mm组关节前、后间隙、减低10.1￣14.0mm组关节上、后间隙左右侧相比较,差异有显著性意义(P<0.05)。垂直距离恢复后,3组关节间隙左右侧差异无显著性意义。结论:无牙颌咬合垂直距离减低后可以导致两侧髁状突位置发生不对称改变。