Physical and spectroscopic methods for the evaluation of the interactions of antimitotic agents with tubulin.

The physico-chemical methods for the study of the binding of ligands to tubulin are examined in-depth, emphasizing the assumptions on which they are based and their limitations. The criteria of specificity and linkage to protein self-association are presented. It is shown that, of the direct equilibrium binding techniques, Hummel-Dreyer gel permeation chromatography and rapid ultracentrifugation are applicable only when binding is not linked to protein self-association. Disc filtration is valid only when the reverse unbinding reaction is very low. Binding linked to protein self-association can be measured by batch gel permeation or by dialysis equilibrium. The indirect techniques, such as fluorescence perturbation or difference absorption spectroscopy are discussed in terms of the assumptions on which they are based. They are shown to be used best only after characterization of the binding by direct techniques. Equilibrium binding parameters can also be deduced from careful kinetic experiments. Comparison of calorimetrically measured enthalpies of binding to van't Hoff enthalpies derived from equilibrium measurements indicates that the method of choice is calorimetric, while comparison with van't Hoff analysis can reveal the existence of reaction steps not detected by equilibrium measurements. Use of other indirect approaches, such as titration of an enzymic activity, can also lead to the detection of additional steps. The criteria are set up for the proper data analysis of ligand binding linked to protein self-association and the selection of the proper mode of linkage. It is shown how the thermodynamic contributions of various moieties of a ligand can be established by a rational structural modification of the ligand and the proper analysis of the binding measurements, in which all non-specific entropic contributions are taken into account. It is demonstrated also how a similar analysis of binding data can lead to conclusions about the reaction pathway from a comparison of equilibrium thermodynamic measurements on judiciously modified ligand molecules.     

支气管扩张症1例

患儿,男,12岁,以反复咳嗽、咯痰5年、加重2个月为主诉入院。5年前开始反复咳嗽,咯黄痰,每年至少发作4次,每次持续10~20 d。近2个月病情明显加重,无咯血,盗汗较重,体质量无减轻,无结核接触史。查体:神清,呼吸平稳,营养中等,咽充血,扁桃体Ⅰ度大。双肺底可闻及密集吸气末中小湿音,以左肺底为主。血白细胞17.4×109/L,中性粒细胞0.84,红细胞5.0×1012/L,血红蛋白151 g/L,血沉53 mm/1 h,降钙素原1.56 ng/L,C-反应蛋白67.4 mg/L。病原学检查:肺炎支原体、肺炎衣原体、腺病毒、合胞病毒、流感病毒、副流感病毒、柯萨奇病毒、埃可病毒、腮腺炎病…     

穿透性角膜移植术后角膜内皮细胞之命运

地２组猴行５。５→５．０ｍｍ穿透性角膜移植术，异种组４只，同种组４只，术前用冷冻创伤＾３Ｈ－ＴｄＲ标记法标记受生角膜内皮细胞，术后１４周摘除眼球，用放射自显影法显示银颗粒的分布。     

Application of trans-abdominal chorionic villus sampling in prenatal diagnosis of chromosomal diseases in first trimester of gestation

Objective:To evaluate the feasibility and safety of prenatal diagnosis by traneabdominal chorionic villus sam-pling(TA-CVS)via the guidance of B-mode ultrasound in the first trimester of gestation.To explore the technique of long time culture and chromosome preparation of villi in early pregnancy.To evaluate the feasibility of the above techniques in the application of the prenatal cytogenetic diagnosis.Methods:One hundred and thirty-five singleton pregnancies at risk were referred from January 2001 to Decem-ber 2007.Results:The average maternal age was 35.2 years.TA-CVS was performed in the 10～13th weeks of gestation and the average gestational age was 10.89 weeks.All attempts at sampling were successful.The rate of operation-associated fetal loss was 0.74%.The failure rate of prenatal diagnosis because of inadequate amount of specimen was 0.The average culture time was 5-7 days.The success rate of the cell culture was 98.5%.No maternal con-temination and bacterial contamination happened.Fifteen cases of abnormal karyotype and one case of confined pla-cantel mosaiciem were diagnosed.Conclusion:TA-CVS appears to be safe and feasible and might to be offered in the prenatal diagnosis in the first trimester of gestation.The technique of long time culture and chromosome preparation of villi is stable and reliable.It is feasible to apply these techniques in the clinical practice of prenatal cytogenetic diagnose in the early pregnancy.     

腹腔镜治疗妇科急症593例临床分析

目的:探讨腹腔镜治疗妇科急症的可行性、安全性及治疗效果。方法:回顾分析2003年7月至2007年10月我院用腹腔镜治疗593例妇科急症患者的临床资料。结果:593例患者均用腹腔镜完成手术,其中异位妊娠512例,手术时间18～75min,平均32min,术中出血10～70ml,平均25ml;盆腔炎、盆腔脓肿47例,手术时间35～90min,平均49min,术中出血45～130ml,平均84ml;黄体破裂、卵巢内膜囊肿破裂、卵巢囊肿蒂扭转34例,手术时间35～80min,平均52min,术中出血20～85ml,平均65ml;术后住院3～7d,平均4.5d,随访12～36个月无复发。结论:腹腔镜手术治疗妇科急症安全可行,且具有良好的效果。     

Reversible Verbal and Visual Memory Deficits after Left Retrosplenial Infarction

The retrosplenial cortex is a cytoarchitecturally distinct brain structure located in the posterior cingulate gyrus and bordering the splenium, precuneus, and calcarine fissure. Functional imaging suggests that the retrosplenium is involved in memory, visuospatial processing, proprioception, and emotion.We report on a patient who developed reversible verbal and visual memory deficits following a stroke. Neuropsychological testing revealed both anterograde and retrograde memory deficits in verbal and visual modalities. Brain diffusion-weighted and T2-weighted magnetic resonance imaging (MRI) demonstrated an acute infarction of the left retrosplenium.     

下颌第一磨牙三维有限元模型的建立

目的：建立下颌第一磨牙三维有限元模型。方法：通过螺旋CT扫描的方法，利用Mimics、Geomagic Studio 7等图像处理软件，HyperMesh网格自动划分软件，通过特定的MSC．MARC有限元软件建立下颌第一磨牙三维有限元模型。结果：准确的建立了牙本质、牙釉质、髓腔、牙槽骨、牙周膜等组织形态的三维有限元模型。结论：本实验建模方法可行性强，方便快捷，具有良好的生物力学与几何力学相似性。为临床口腔医师提供了一种简捷而精确的有限元建模方法。     

阶梯状分离法在睑袋整形术中的应用

目的：在传统睑袋整形术式分离层次的基础上进行改进，以便获得更佳的术后矫治效果，减少术后并发症。方法：在切口下缘皮下轮匝肌表面分离5-10mm，顺肌纤维走行方向由外向内剪开轮匝肌，在眶隔浅面分离轮匝肌肌皮瓣达眶缘，在眶骨表面分离轮匝肌的附着及外眦部肌肉，皮下悬吊固定于外眦眶缘骨膜上，观察手术效果。结果：术后通过3-6个月随访无一例出现睑球分离、睑外翻、下睑退缩、外眦下垂、眼袋复发等并发症。结论：阶梯状分离法是睑袋整形术中的技术改进，术后效果确切、可靠。