儿童生殖细胞瘤全脑放射治疗中自适应消除摆位累积误差新技术探讨

目的 以影像引导放射治疗(image guided-radiotherapy, IGRT)为基础探讨儿童生殖细胞瘤全脑自适应放射治疗(以下简称放疗）(adaptive radio therapy,ART）可行性,为临床全脑ART提供依据。方法 回顾性研究首都医科大学附属北京天坛医院放射治疗科20例中枢神经系统生殖细胞肿瘤(germ cell tumors, GCTs)行全脑预防性照射的放疗患者。每例患者治疗前三次及后每周行一次锥形束电子计算机断层扫描(cone beam computed tomography,CBCT),共7次。记录整个治疗过程中左右(lateral, LAT)、进出(longitudinal, LNG)、升降(vertical, VRT)方向上的摆位误差值。原计划命名为Plan_A,将因摆位误差值产生新的治疗中心点(treatment center point,ISO)回归治疗计划系统,不改变射野权重、射野分布情况下进行体积剂量计算,用Plan Sum功能相加摆位累积误差产生新计划得到Plan_B。将摆位累积误差产生的新计划用Acuros XB算法重新快速优化后用Plan Sum功能相加得到Plan_C。对比Plan_A、Plan_B、Plan_C的靶区及危及器官(organ at risk, OAR)剂量变化并用Wilcoxon配对符号秩检验证统计学差异。结果与Plan_A相比,Plan_B 均匀性指均匀性指数（homogeneity index, HI）95计划靶区（planning target volume, PTV）、 HI98 PTV为1.058 4~1.084 7。适形度指数(conformity index, CI）PTV为0.934 4。 临床靶区（clinical target volume, CTV）D_min相对偏差为－7.22%,P值为0.000 7。OAR相对偏差为－0.1%~9.8%。与Plan_ A相比,Plan_ C的HI95 PTV、 HI98 PTV为1.056 9~1.078 8。CI PTV为0.936 5。CTV D_min相对偏差为－1.69%,P值为0.545 9。OAR相对偏差为－0.15%~3.40%。结论儿童生殖细胞瘤全脑放疗摆位累计误差对靶区及危及器官剂量差异有统计学意义,摆位累计误差导致靶区均匀性及适形度变差,CTV的D_min 变化超过5%,OAR受量增高。ART再计划可以让靶区均匀性和适形度及危及器官受量接近原计划。同时Plan_B虽然存在相对偏差,但是危及器官的绝对剂量在合理范围内。     

AO肩锁钢板钩治疗重型肩锁关节脱位

目的评估AO肩锁钢板钩治疗重型肩锁关节脱位的手术疗效.方法回顾性分析两年来27例手术病人的手术治疗和疗效.结果手术方法符合生理结构,手术时间平均30分钟,内固定牢靠.根据Murley和Constant[1]评分,优良率94%.结论 AO肩锁钢板钩治疗重型肩锁关节脱位,手术方法简单,疗效可靠,允许病人术后早期功能锻炼.     

Collagen-coated polylactide microspheres as chondrocyte microcarriers

Polylactide (PLA) microspheres were coated with collagen for cell culture and injectable cell carriers. Utilizing a method of emulsion-solvent evaporation, PLA microspheres with diameter ranging from 180 to 280 microm were prepared, followed with aminolysis in hexanediamine/n-propanol solution to introduce free amino groups on their surfaces. After the amino groups were transferred into aldehyde groups by a treatment of glutaraldehyde, collagen type I was covalently coupled via Schiff base formation between the aldehyde groups and the amino groups on collagen molecules. Meanwhile, physically entangled collagen molecules were retained following a grafting-coating protocol to yield microspheres coated with larger amount of collagen. Aminolysis resulted in weight loss of the microspheres following a linear relationship with the aminolysis time. The NH2 and collagen contents existed on the microsphere surface were quantitatively determined by ninhydrin and hydroproline (Hyp) analyses, respectively. Larger amount of collagen was immobilized on the microspheres with higher content of NH2. In vitro chondrocyte culture revealed that the cells could attach, proliferate and spread on these PLA microspheres, in particular on the ones having higher content of collagen. These results show that the collagen-coated PLA microspheres are promising candidate as cell microcarriers.     

Inhibitory actions of serotonin on glutamate release in dorsal medulla suppress systemic arterial pressure of cats

The role of serotonin and glutamate release in dorsal medulla (DM) for regulation of systemic arterial pressure (SAP) was examined with microdialysis and high performance liquid chromatograph in anesthetized cats. KCl-perfusion in DM increased serotonin and glutamate concentrations in DM. Perfusion of serotonin resulted in decreases in glutamate concentration and SAP. Perfusion of alaproclate, a serotonin reuptake inhibitor that produced an increase in serotonin concentration in DM, had the same results as perfusion of serotonin. In conclusion, serotonin and glutamate appeared to be tonically and endogenously released from nerve terminals in DM, and the decrease in SAP could be attributed to the decreased glutamate release resulting from inhibitory action of serotonin in DM. The putative roles of serotonin and glutamate in DM may be important in SAP regulation.     

Fos oncoprotein expression in the rat forebrain following muscimol-induced absence seizures

Fos oncoprotein expression is a marker of neuronal activation following seizures. Here, using this method we examined the anatomical locations of muscimol-induced absence seizures in the rat forebrain. Six hours after a systemic injection of muscimol a massive Fos immunoreactivity appeared in the olfactory system, retrosplenial cortex and paraventricular thalamic nucleus, whereas other cortical areas contained low level of Fos expression. These results provide the first functional morphological evidence suggesting that these forebrain structures with Fos expression may play an important role in the pathophysiology of muscimol-induced absence seizures.     

一种可生物降解温度敏感型聚乙二醇-聚己内酯-聚乙二醇水凝胶的合成和表征

合成了一系列分子量较低的聚乙二醇．聚己内酯-聚乙二醇（Poly（ethylene glycol）-Polycaprolactone-Poly（ethylene glycol），PEG-PCL—PEG）三嵌段共聚物。分别采用FTIR和1H—NMR对其结构进行了表征。所合成的PEG-PCL-PEG共聚物具有良好的水溶性，当水溶液浓度高于临界凝胶浓度（Critical gel concentration，CGC）时，随着温度的变化聚合物水溶液会呈现特有的凝胶-溶胶转变。研究了共聚物亲水疏水链段的比例和长度，以及热历史等对凝胶-溶胶转变行为的影响。通过调节上述条件，可以在一定程度上拓宽凝胶-溶胶转变温度范围，有助于PEG—PCL-PEG水凝胶在可注射药物控制释放系统等方面的应用。     

白细胞介素—1对大鼠下丘脑室旁核Fos癌蛋白和CRF的诱导作用

将白细胞介素-1(IL)注入大鼠侧脑室,用Fos癌蛋白抗体免疫组化法检测了下丘脑室旁核的激活神经元:大量位于含促肾上腺皮质激素释放因子(CRF)相应区域的室旁核小细胞部神经元呈Fos免疫强阳性。Fos和CRF的免疫双染色显示了许多Fos免疫阳性神经元也呈CRF免疫阳性。此外,在IL-1注射动物中,CRF的免疫阳性显著加强,提示CRF合成增加。