大鼠坐骨神经分支选择结扎切断模型的建立及脊髓背脚N-甲基-D-天冬氨酸受体检测

目的采用免疫组织化学方法,观察SNI模型大鼠脊髓背角神经元NMDAR的表达。方法健康雄性SD大鼠15只,随机分为3组：对照组（C1组）、假手术组（C2组）和生理盐水组（NS组）,每组5只。C1组不做任何处理,其他2组均根据改良Yaksh法进行鞘内置管。置管5d后,NS组按Woolf等方法建立神经病理性疼痛模型（SNI）,C2组除不损伤神经外处理同NS组;制模2d后,C2组和NS组用微量注射器鞘内注射20μL生理盐水,然后用生理盐水冲管（共20μL）。在30min后,C2组、NS组均进行疼痛行为学观察。3组均在注药后2h处死大鼠,用免疫组化法观察大鼠腰5节段水平脊髓背角NMDAR的表达。结果C1组和C2组在各时点均无机械性异常疼痛出现,热刺激后爪退缩潜伏时间差异也均无统计学意义（P〉0.05）;NS组在SNI手术后第1天和第2天出现明显的痛觉过敏（机械性异常疼痛痛阈降低）,与C1组比较差异有统计学意义（P〈0.01）,但对热刺激的后爪退缩潜伏时间与C1组比较差异无统计学意义（P〉0.05）;NS组大鼠脊髓背角NMDAR免疫阳性细胞数量与C1及C2组比较明显增加,两者之间差异有统计学意义（P〈0.05）;NS组的脊髓背角NMDAR免疫阳性细胞数密度值与C1,C2组相比显著增高（P〈0.05）,NS组的阳性细胞光密度值较C1组和C2组增高（P〈0.05）。结论SNI模型可引起大鼠损伤侧肢体机械性痛觉过敏,但对热刺激不敏感;SNI模型引起大鼠脊髓背角神经元NMDAR表达上调。     

1，25-二羟维生素D3对糖尿病大鼠肺脏的保护作用及机制

目的观察1,25-二羟维生素D3[1,25-（OH）：D,]对糖尿病大鼠炎性水平及肺组织Toll样受体4（TLR4）表达的影响,探讨其肺保护作用及机制。方法将90只SD大鼠随机分为对照组（C组）10只及模型组80只,模型组经尾静脉注射STZ制备糖尿病模型,C组注射等体积柠檬酸缓冲液;将模型组造模成功的75只大鼠随机分为糖尿病组（D组）,1,25-（OH）：D,大、中、小剂量干预组（H、M、L组）及精蛋白锌胰岛素干预组（Y组）各15只,其中H、M、L组分别予0．3、0．15、0．025μg/（kg·d）的1,25-（OH）：D3灌胃,Y组予胰岛素颈后皮下注射,c组和D组予蒸馏水2mL灌胃,均为1次/d、连续16周,16周后所有动物均采用股动脉放血处死,立即取肺脏组织置于10％甲醛及液氮中保存。测定各组血糖及血清CRP水平;采用HE、Masson染色法观察肺组织形态学变化,免疫组织化学法检测TLR4、NF-KBp65的蛋白表达;采用PCR法定量检测TLR4、MyD88、NF-KBp65的mRNA表达。结果①D组血糖及血清CRP水平均显著高于C组（P〈0．01）,各干预组均不同程度低于D组,尤以H组为著（P〈0．01）。②D组肺泡壁重度增厚、肺间质明显增生、大量炎症细胞浸润,H、Y、M及L组肺泡壁轻到中度增厚、炎细胞浸润明显;与c组比较,余5组TLR4、NF-KBp65蛋白表达有所升高,其中H、Y组显著低于D组。③D组,TLR4、MyD88和NF-KBp65的mRNA表达显著高于C组（P〈0．01）,各干预组表达水均低于D组。肺组织TLR4mRNA表达与MyD88mRNA（r=0．610）、NF-KBp65mRNA表达（r=0．744）均呈正相关,P均〈0．001;MyD88mRNA与NF-KBp65mRNA表达亦呈正相关（r=0．609）,P〈0．001。结论1,25-（OH）：D,可能通过TLR4介导的炎症途径对STZ诱导的糖尿病大鼠肺脏病变发挥保护作用。     

Dynamic probabilistic model for determination of optimal timing of surveillance chest radiography in pediatric Hodgkin disease

A dynamic probabilistic model based on hazard rate analysis, Monte Carlo modeling, and lead-time estimation techniques was developed to determine the optimal timing and frequency of chest radiography in the monitoring for relapse of children with treated Hodgkin disease. The analysis incorporates the performance characteristics of chest radiography, the natural history of the disease process, and therapeutic efficacy as a function of earliness of detection in the determination of optimal strategy. Examples of the model applied to the experiences of Stanford Medical Center and St. Jude Children's Research Hospital illustrate the utility of such a model in customizing an optimal monitoring strategy for a specific institution and clinical experience. The results suggest that monitoring protocols significantly overutilize chest radiography in the evaluation for recurrent Hodgkin disease in children.     

Quantum chemical study of the electronic and conformational characteristics of adenosine and 8-substituted derivatives: functional implications in the mechanism of reaction of adenosine deaminase

A quantum chemical study of 10 substrates of adenosine deaminase is performed. The conformational preference around the glycosidic bond of several 8-substituted derivatives of adenosine is studied using semiempirical modified neglect of diatomic overlap (MNDO) and Austin model 1 (AM1) methods. All the compounds studied show preference for the anti conformation; the syn - anti energetic differences calculated are small and in excellent agreement with experimental data. A relationship between the ab initio molecular electrostatic potential minimum energy of N3 and the syn - anti energetic difference is found. A highly significant relationship is also found between the ab initio net charge over the purine and pyrimidine rings and the logarithm of the maximum rate of deamination (log Vm) of the nucleosides by adenosine deaminase. In contrast, no significant relationship is found between the anti preference of 8-substituted derivatives of adenosine and their log Vm of deamination.