铰链式冠外附着体的结构强度分析

目的探讨铰链式冠外附着体设计的合理性.方法采用有限元应力分析的实验方法,分析铰链式冠外附着体阳性结构L形球体的应力分布情况,对其结构强度进行测试.结果在附着体阳性结构L形球体的转角处应力最大,应力值为321.847MPa.结论该铰链式附着体的结构强度符合临床设计要求.     

Nerve growth factor and tyrosine kinase A in human salivary adenoid cystic carcinoma: expression patterns and effects on in vitro invasive behavior.

PURPOSE: Perineural invasion is a frequent occurrence in salivary adenoid cystic carcinoma (ACC) and may prevent complete surgical resection. Studies have indicated that nerve growth factor (NGF) and its high-affinity receptor tyrosine kinase A (TrkA) may play a role in perineural invasion in several malignancies in which perineural invasion is observed. The present study was conducted to investigate the expression of NGF and TrkA in salivary ACC and to examine the effects of NGF on adhesion, migration and invasion capacities of a salivary ACC cell line (SACC-83) in vitro. PATIENTS AND METHODS: Expression of NGF and TrkA was explored using immunohistochemistry in paraffin-embedded tissues of 32 cases of salivary ACC. The effects of NGF on in vitro adhesion, migration, and invasion capacities of the SACC-83 cell line were examined using an MTT assay and a modified Boyden chamber assay respectively. RESULTS: In ACC specimens, 31 (96.9%) and 32 (100%) tumors showed immunoreactivity for NGF and TrkA respectively. Significant correlations were found between NGF/TrkA expression levels and perineural invasion (P < .05). In cell adhesion assay, the percent adherences of SACC-83 cells co-cultured with 25 ng/ml NGF at 1.5 hours and 5, 25 ng/ml NGF at 6 hours were significantly higher than that co-cultured with 0 ng/ml NGF (P < .05). However, high concentration of NGF (500 ng/ml) resulted in a significant inhibition of invasion (P < .05). CONCLUSION: Overexpression of NGF and TrkA in human salivary ACC tissues may constitute a reason for perineural invasion in salivary ACC.     

异落新妇甙的结构研究

从百合科菝葵属植物土茯苓(Smilaxg labra Roxb.)根茎的乙醇提取物中分得一个新的天然化合物(I),命名为异落新妇甙(isoastilbin)。根据元素分析,UV,IR,¹H-NMR,¹³C-NMR,2DNMR及FAB-MS,确定化合物I的结构为5,7,3',5'-四羟基二氢黄酮醇-3-O-α-L-鼠李糖甙。     

中和法制备水杨酸微晶

为增加水杨酸在各类制剂中的分散度，便于制备，提高疗效，采用酸碱中和法将其制成微晶。先将水杨酸与１ｍｏｌ／Ｌ氢氧化钠反应成盐溶解，然后用１ｍｏｌ／Ｌ盐酸中和析出微晶。所得微晶呈针状，色白，膨松，在电镜下测得平均粒径为１６μｍ。各项理化标准符合中国药典１９９５年版规定。本法微晶得率为９８％。     

计算机导航在骨科手术中的应用

目的将计算机导航技术应用于骨科手术,并对其进行初步分析。方法2004年2～12月,计算机导航系统辅助下共行134枚椎弓根螺钉固定,51枚股骨颈骨折空心钉内固定,58枚交锁髓内钉远端交锁螺钉固定。结果所有病例全部在导航下完成手术,术中明显减少C型臂X线机透视次数,未发生血管和神经损伤并发症。结论计算机导航手术安全有效,更有利于微创手术的开展。     

Primary amyloidosis of the urinary bladder.

Amyloidosis is a systemic disease that usually occurs in the gastrointestinal tract or in muscular or adipose tissue. Primary amyloidosis of the urinary bladder is a rare disease that can mimic bladder cancer on cystoscopic examination as well as in its clinical presentation of painless gross hematuria. This report describes a 49-year-old male with repeated painless gross hematuria, who underwent transurethral resection of a suspected bladder tumor. Pathologic examination revealed papillary urothelial hyperplasia with vascular ectasia and no signs of malignancy. Massive gross hematuria occurred 2.5 years later. Cystoscopy showed multiple papillary lesions with yellowish-brown submucosal plaques on the posterior bladder wall. A second transurethral tumor resection was performed and histologic examination revealed plasma cell infiltration and eosinophilic amorphous deposits in the subepithelial stroma and vascular wall. The deposits were positive for Congo red and apple-green birefringence under polarized light examination but negative for Masson's trichrome stain, indicating that they were not fibrotic in nature. Hence, the diagnosis of amyloidosis of the urinary bladder was confirmed. Screening for amyloidosis was negative in other organ systems and the patient has remained disease-free up to the last follow-up 4 years after the second transurethral resection. Amyloidosis should be considered in the differential diagnosis of patients with recurrent hematuria who have symptoms characteristic of bladder cancer but negative pathologic study for malignancy. Correct diagnosis relies on clinical alertness and the use of a special staining technique during pathologic examination.     

单侧鼻前庭切口经蝶切除垂体腺瘤

对１６例垂体腺瘤采用单侧鼻前庭切口经蝶切除，效果满意，既可减少手术创伤，又缩短了手术距离，且避免了美容缺陷，是一种设计巧妙，较为实用的手术方法，尤其适用于生长激素腺瘤。     

人脑胶质瘤逃避免疫监视机制的研究

为研究胶质瘤逃避免疫监视的机制，检测了胶质瘤体外细胞系培养上清（SN）抗PHA－P刺激正常人及胶质瘤患者外周血淋巴细胞增殖的作用。证实了胶质瘤可自分泌免疫抑制因子。经抗TGFβ2单抗中和SN试验，TGFβ2免疫组化染色及Northern杂交进一步表明该因子主要成分为TGFβ2并对胶质瘤患者血浆皮质醇，生长激素及儿茶酚胺含量及细胞免疫功能进行检测，发现血浆去甲肾上腺素显著降低，其水平与CD8亚群％呈负相关，与CD4／CD8比值及淋巴细胞增殖率呈正相关。初步提示存在胶质瘤的情况下，神经－免疫调控紊乱，可能起着抑制性调节作用。     

岭南医药启示录(十二)

17清末民初广东伤寒学与温病学之发展（上） 清代至民国时期，广东伤寒学与温病学有长足的发展，表现为著名的医家与著作的林立，由师徒相授而举办学校，应对传染病能力的增强等等。考其原因，主要：一是病谱的变化，海外传来许多新的疫病如霍乱，烂喉痧等，老传染病如鼠疫，天花等的不断爆发流行。二是西医传人，废止中医之举屡起，中医危亡不能不起而抗争，研究理论，提高临床诊治水平、举办学校、出版著作与刊物都势在必行，实际是寻求奋发图强、发展中医之路。现就清末民初有代表性的几位伤寒学家与温病学家略加介绍，以见一般。