IS THE SEVERITY OF OSTEOSCLEROSIS OF FLUOROSIS PROPORTIONAL TO THE DOSE OF FLUORIDE INTAKE?

Histomorphometric study was made on a series of sections of undecalcified epiphyseal femoral specimens from rats with experimental fluorosis. The results revealed osteosclerosis in Group A (5 ppm) being more severe than that in Group B (25 ppm) With the increase of fluoride dose, the parameters fell down instead of increased in parallel. There is seemingly a threshold over which osteosclerosis in fluorosis becomes less severe. In contrast to Bely's conclusion the authors proposed that, fluoride toxi- city, besides decreasing the number of osteoblasts, may also activate the osteoblasts. The number of osteoblasts may be increased with relative lower dose of fluoride also. The net outcome is the in crement in bone volume. When toxic dose of fluoride is higher enough (higher than the proposed threshold), however, the number of osteoblasts and its activity are inhibited. So are the osteocytes. This interpretation may be the cytological basis for osteosclerosis in the experimental fluorosis.     

协同刺激分子CD28在结核杆菌抗原体外激活人外周血γδT细胞中的作用

目的 :为了探讨CD2 8协同刺激分子在结核杆菌 (Mtb)低分子多肽抗原体外激活人外周血γδ T细胞中的作用。方法 :采用激发型抗CD2 8单抗模拟第二信号 ,Mtb低分子多肽抗原作为刺激原 ,对纯化的人外周血T细胞进行体外刺激和培养 ;用流式细胞仪检测γδ T细胞上CD2 8分子的表达、γδ T细胞的增殖效应及活化的γδ T细胞上CD6 9分子的表达。结果 :人外周血γδ T细胞中有 5 0 %左右表达CD2 8分子 ;抗CD2 8单抗协同Mtb抗原可刺激γδ T细胞的活化和增殖 ;但抗CD2 8单抗或Mtb抗原单独刺激则无作用。活化的γδ T细胞表面表达CD6 9分子。结论 :Mtb抗原在选择性活化人外周血γδ T细胞时需要第二信号的参与 ;CD2 8在Mtb抗原激活γδ T细胞时可提供协同刺激信号 ;CD6 9可作为γδ T细胞的早期活化标志。     

神经活素对Pc12细胞作用的初步观察

从胎脑、颌下腺、肌肉组织中制备神经活素。其性能同脑活素一样：可促进Ｐｃ１２细胞的突起生长，提高其胞浆内乳酸脱氢酶活性，电泳显示二者有相同的三条带。提示：神经活素有可能替代脑活素应用于临床。     

人皮质骨矿化基质中骨盐框架结构

目的：研究人皮质骨矿化基质中骨盐的框架结构及框架中骨微间隙。方法：应用透射电镜、场发射扫描电镜观察、电脑图像分析及能谱分析，分析无骨病成人长骨、扁骨２００例骨盐分布特征。结果：骨盐框架结构由微柱、微梁、微小梁、弓状梁、致密点、隔板和骨微间隙构成。骨微间隙由洞、内衬和壁组成，洞平均直径为８４．４±７５．６ｎｍ，与骨小管相比有显著差异（Ｐ值＜０．００１），平均密度为１１～１７个／μｍ２，与骨小管之比超过１０：１。骨盐分针形结晶和微颗粒结晶。结论：骨盐框架结构及骨微间隙是骨盐在人皮质骨矿化基质中的存在形式，可能与骨盐吸收、沉着有关。     

急性心肌梗塞静脉溶栓治疗冠脉再通者早期ST段再抬高的临床意义

急性心肌梗塞早期静脉溶栓治疗后，一些溶栓再通患者中，可见早期降低的ＳＴ段再度出现抬高现象。本文回顾溶栓成功者８１例，其中早期出现ＳＴ段再度抬高者２１例（占３５％），与ＳＴ段非再度抬高者相比，ＣＰＫ、ＣＰＫ－ＭＢ峰值，心功能及院内死亡率等无显著差异。笔者认为，此现象也为再通的标志之一。因此，急性心肌梗塞溶栓治疗的早期连续监测心电图对确认再通与否非常重要     

中老年人24小时动态血压变化的研究

目的探讨血压正常老年患者和老年高血压患者24h动态血压波动规律及与靶器官损害的关系.方法采用无创伤袖带式动态血压监测仪检测36例中年人(对照组),50例血压正常老年患者,60例老年高血压患者的动态血压.结果血压正常老年患者较中年血压正常者24h动态血压呈杓型曲线的比例明显下降.血压正常老年患者,血压昼夜波动曲线与心、脑、肾损害无相关性.老年高血压患者,血压曲线呈非杓型者比例增高,血压昼夜节律消失较节律正常的高血压患者有更显著的靶器官损害.结论对于非高血压患者,随年龄的增加,血压昼夜节律消失者增多,血压曲线变化与心、脑、肾损害无关,可能与原发病有关.对于高血压患者,血压昼夜节律紊乱可作为靶器官损害的预测因子.     

Structure-activity studies with chiral isomers and with segments of the antimitotic marine peptide dolastatin 10

Eighteen configurational isomers of the antimitotic peptide dolastatin 10 (Bai et al., Biochem Pharmacol 39: 1941-1949, 1990) derived from Dolabella auricularia, together with segments obtained as precursors in its synthesis (Pettit et al., J Am Chem Soc 111: 5463-5465, 1989), were examined as inhibitors of tubulin polymerization and as inhibitors of growth of L1210 murine leukemia cells in culture. Dolastatin 10 consists of four amino acids (in order from the amino terminus: dolavaline, valine, dolaisoleucine, and dolaproine), three unique to D. auricularia, linked to an unusual primary amine (dolaphenine, probably derived from phenylalanine) at what would otherwise be its carboxyl terminus. Dolastatin 10 has nine asymmetric carbon atoms, and available isomers included alternate configurations at five positions (positions 9 and 10 in the dolaproine moiety and positions 18, 19 and 19a in the dolaisoleucine moiety). For tubulin polymerization, only alterations at positions 18 and 19 resulted in loss of inhibitory activity of the isomer. In addition, a tripeptide containing dolavaline, valine and dolaisoleucine with all asymmetric carbons identical configurationally to those in dolastatin 10 was found to be about 30% as effective as dolastatin 10 in inhibiting tubulin polymerization. Cytotoxic effects were much more sensitive to alterations in the dolastatin 10 structure. The only modification which did not lead to reduced cytotoxicity was reversal of configuration at position 19a in the dolaisoleucine moiety. Both this isomer and dolastatin 10 had IC50 values of less than 1 nM. Several other isomers had IC50 values with the L1210 cells in the range of 30-90 nM, but these did not correlate well with their inhibitory effects on tubulin polymerization. The tripeptide effective as an inhibitor of tubulin polymerization had no activity against the L1210 cells.     

阴股沟皮瓣显微解剖学特征及其在组织修复功能重建中的应用

目的：明确阴股沟皮瓣的显微解剖基础，为临床应用此皮瓣提供解剖依据。资料来源：应用计算机检索Medline1991-01／2005-01的相关文章，检索词“pudendal-thigh flap，micranatomy”，并限定文章语言种类为English。并且手工检索《中文科技资料目录一医药卫生）1998-01／2005-01的相关文章，检索途径：分类途径。 资料选择：对资料进行初审，并查看每篇文献后的引文。纳入标准：①随机对照的基础及临床试验。②无论是否为单盲，双盲或非盲法。排除标准：重复性研究或综述性文章。 资料提炼：共检索到42篇相关文章，21篇文献符合纳入标准，排除的21篇文献为内容陈旧或重复。 资料综合：阴股沟区动脉血液供应充足，并且位置均比较恒定，尤以阴部外动脉最为恒定。静脉回流丰富，神经支配可靠。阴股沟皮瓣是位于股内侧上方与会阴部之间的无毛区域，上界平耻骨联合上缘水平，下界为两侧坐骨结节连线，内侧界为阴囊或大阴唇外侧缘，外侧界为股内侧皱襞，自阴囊（唇）外侧缘向大腿内上方延伸约5cm包括的范围。该区动脉血液供应丰富，计有阴部外动脉，闭孔动脉前皮支，阴囊（唇）后动脉的外侧支，旋股内侧动脉的皮支，股内侧的主要动脉支，以及来自阴部内动脉的肛动脉（直肠下动脉）等，并且位置均比较恒定，其中尤其以阴部外动脉最为恒定。在阴股沟区，阴囊（唇）后动脉与旋股内动脉、闭孔动脉前支及阴部外动脉的分支存在广泛的吻合并在内收肌内侧以上的深筋膜层形成血管网。进入阴股沟区的多支血管相互吻合成网。阴股沟区静脉回流丰富，神经支配可靠。 结论：阴股沟皮瓣血运丰富，解剖简便易行，切取方便，供区隐蔽，再造性器官外形及恢复神经感觉均取得较为理想的效果，是一种值得推广的方法。