Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: IV modulation of membrane fluidity of leukemic cell lines and tonsillar cell stimulated with McAbs

Summary In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane-fluidity induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However, the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding isotypic and idiotypic determinants of IgM on the cell membrane.     

Effect of meal volume on gastric emptying

Abstract While the volume of a liquid meal has been identified as the principal accelerator of gastric emptying of liquids, the relationship between meal volume and gastric emptying of solids has been controversial. With solid foods, the need to reduce solid foods into small particles (trituration) before passage might obscure the effect of meal volume on solid propulsion. To distinguish trituration from driving force as the rate-limiting factor for emptying, 75 (1.6 mm) nylon spheres were fed along with different amounts of steak meals (150, 300 and 600 g), or alternatively, 50, 100 or 200 (1.6 mm) nylon spheres were fed to six dogs with 300 g steak meals. To examine the effect of meal volume on gastric emptying, we studied the effect of different meal volumes on the speed of gastric emptying of liquids (150, 300, 600 and 1200 ml of phosphate buffer) and solids (150, 300 and 600 g of cooked beef steak) in five dogs with duodenal fistulas. Intestinal inhibition was eliminated by diverting all chyme through the fistulas. In the absence of intestinal feedback, we found that gastric emptying of steak and spheres were different in that steak emptying was independent of meal volume (g min^-1 was constant across 150–600 g) while sphere emptying was affected by the number of spheres in the stomach and that liquid emptying was dependent on the meal volume (ml min^-1 increased across 150–1200 ml). Thus, meal volume accelerated gastric emptying provided the process is not rate-limited by trituration.     

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.     

颈椎椎体次全切除钛网钉板系统的临床应用

目的探讨颈椎前路椎体次全切除钛网钉板植骨融合的临床效果。方法自2001年3月～2003年3月间应用颈前路椎体次全切除钛网植骨融合及钉板固定治疗颈椎管狭窄性疾病22例，其中4例患者行2椎体次全切除3节椎间隙减压手术。术后观察减压、固定、融合及神经功能恢复情况，并行X线摄片或CT扫描检查。结果患者获6～12个月随访，神经功能得到不同程度改善，无加重情况。椎间隙高度无丢失、无成角，均获得骨性融合。术后3d在颈围领固定下下床活动，4周后可恢复较轻工作。结论此术式可避免传统手术方法的缺点，即不取自体髂骨，融合率高，稳定性好，并减压彻底，疗效好，是一种值得推广的新技术。     

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。     

我国临床科研中存在的问题与思考

推动我国临床医学发展的成就1998年,王秀峰教授[1]总结了我国建国50年来取得的14大医学科技成果。这些成果具有原创性,影响深远且广泛,得到国际公认;同时解决了某些较急迫问题,或形成了一门新的医学学科,推动了我国乃至世界医学进步。巴德年院士[2]将下列研     

老年移位性股骨颈骨折手术治疗选择

老年移位性股骨颈骨折患者骨折愈合缓慢、全身情况较差等,使得手术治疗颇为棘手.在选择手术方法时要综合考虑各种因素.内固定治疗引起的创伤相对较小,但手术后并发症较多;半髋关节置换术后并发症大大减少,但远期效果不如全髋关节置换术.该文就内固定术、半髋关节置换术、全髋关节置换术及其治疗中的若干问题作一综述.     

营养素食预防化疗患者便秘的效果观察

目的 观察营养素食预防化疗患者便秘的效果。方法 选择128例化疗患者，随机分为观察组和对照组各61例，对照组常规正常饮食，观察组于化疗开始当天实施营养素食．连续7～10d，比较两组患者便秘发生率及体重、血红蛋白、白蛋白等指标。结果　对照组便秘发生率显著高于观察组（P〈0．01）；两组化疗后营养指标比较，差异无显著性意义（均P〉0．05）。结论　营养素食对化疗患者便秘有较好的预防作用。