Brain abscess in Saudi Arabia

There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%.     

Evaluation of neural fold fusion and coincident initiation of spinal cord occlusion in the chick embryo.

Although it is known that rapid expansion of the vertebrate brain begins near the time that the spinal neurocoel is occluded, it still remains unknown when occlusion occurs in relation to neurulation. Since both morphogenetic events are critical for normal brain growth, it is important to decipher the temporal relationship between the two processes. This study assessed the temporal relationship of the two events with the rationale that if it could be demonstrated that occlusion occurs coincident with the completion of neurulation, then it could be argued that factors shown to direct neurulation could also initiate occlusion. Nearly 600 chick embryos (stages 9- through 12+) were cultured atop egg-agar, the caudal extent of neurulation determined, the cranial five pairs of somites removed and the neurocoels assessed for occlusion. In stage 9- through 10- chicks, neurulation of the spinal cord is incomplete. Stages 10 through 12+ exhibit neurulation and occlusion from the 8th to 19th somites. When lateral tissues were removed in embryos 8 through 10-, the neural folds became dysraphic whereas in embryos stage 10 and older, the folds remained fused dorsomedially and occluded. The only surgical manipulation that was found to prevent occlusion was elimination of the lateral tissues responsible for elevation and closure of the neural folds. Analysis of particular components of the lateral tissues essential for convergence, by treating embryos (n = 75) with chemicals known to degrade tissue-tissue bonds or specific components of the perineural matrix, indicated that more than 75% of the embryos treated with EDTA, EDTA plus Ca2+, trypsin, collagenase, or hyaluronidase exhibited little or no effect on convergence, dorsomedial fusion, and concomitant occlusion.     

铅的肾细胞毒性及锌的保护作用

铅的肾细胞毒性及锌的保护作用陈卫平，刘世杰（北京医科大学公共卫生学院，１０００８３）本实验采用由猪肾脏起源建株并具有肾近曲小管功能的ＬＬＣ－ＰＫ１细胞系，从细胞水平上研究了铅对肾细胞的毒性及锌的保护作用。所选用的指标为细胞存活率和上清液中的乳酸脱氢酶...     

Astrocyte and microglial motility in vitro is functionally dependent on the hyaluronan receptor RHAMM

RHAMM (Receptor for Hyaluronic Acid Mediated Motility) has been identified as a receptor for the extracellular matrix component hyaluronan (HA) and was recently shown to be essential for the locomotion of normal and transformed peripheral cells. Until now the potential role of RHAMM in the motility of neural-derived cells has not been investigated. Here, we report that cultured primary astrocytes, astrocyte cell lines, and microglia express this receptor and exhibit RHAMM-dependent motility. Immunocytochemical localization of RHAMM showed that it was often present as aggregates at the periphery of cells in contact with one another or concentrated on protruding processes of isolated cells. Glial cells contained 50 and 72 kDa forms of RHAMM, and both of these forms were found to have HA binding capacity. Time lapse imaging of cell locomotion revealed a significant inhibition of motility and process elongation by neutralizing anti-RHAMM antibodies and by peptides corresponding to the HA binding domains of RHAMM. These results demonstrate that RHAMM serves a role in glial cell locomotion in vitro and provide the basis for investigations of the motile behavior of glial cells in vivo after CNS injury.     

晕得宁毒性的实验研究

晕得宁为复方中药制剂,济宁市第一人民医院耳科用于治疗美尼尔氏病疗效良好,我室对此方剂进行了毒理学研究。急性毒性实验表明,小鼠一次灌胃量达人用量的200倍(n=10),观察72小时,未见异常表现及死亡。亚急性毒性实验:实验组12只家兔(分成大、中、小剂量三组),连续给药三周,其观察指标包括体重、血常规、肝功(GPT)和肾功(BUN),与对照组(n=4)相比,均无异常(P>0.05);病理检查10兔正常,另2兔患有肺炎。其中1只病兔属大剂量组,于给药第20～21天出现腹泻并死亡,可能与方剂组成中半夏的毒性有关。作者认为晕得宁的毒性较小;鉴于半夏有毒,临床用药宜避免大剂量、长期应用。     

Schwann cell invasion of the conus medullaris: case report

As Schwann cells possess regenerative capabilities there is intense interest concerning their role in central nervous system (CNS) regeneration. We report on a case of an intramedullary schwannoma involving the conus medullaris and spinal cord above it. We discuss the possible origin of these cells and the mechanisms by which these cells may invade the CNS. We offer imaging and discuss experimental studies to support our hypothesis. This case concerns a 48-year-old man, who presented with a 6-month history of bilateral lower extremity weakness. Magnetic resonance imaging (MRI) revealed an intramedullary tumour extending from the conus to T11. At operation, following laminectomy and durotomy, a schwannoma was dissected free from the conus. Total gross resection of tumour was achieved. The patient made an uneventful and full recovery. This case shows that Schwann cells can invade the CNS. Manipulation of the transitional zone astrocytic barrier may offer a potential avenue for Schwann cells to enter the CNS in pathological states.     

植入后全胚胎培养的培养基pH值改变对大鼠胚胎生长发育的影响

目的　探讨植入后全胚胎培养培养基最适pH值。方法　分离 9.5天龄Wistar大鼠胚胎 ,分别在实验组 (即不同pH :5 .5 ,6 .0 ,6 .5 ,7.0 ,7.5 ,8.0 ,8.5 ,9.0 )和对照组 (pH为 8.2 )的培养基 (1 0 0 %大鼠即刻离心血清 )中体外旋转培养4 8小时 ,观察pH值的改变对胚胎生长发育的影响。结果　与对照组比较 ,当培养基pH为 6 .5、6 .0和 9.0时培养胚胎的生长发育明显受到影响 (P <0 .0 5 ) ,胚胎畸形率和死亡率增高 (P <0 .0 5 )。当培养基pH为 5 .5时 ,培养胚胎死亡率达1 0 0 %。结论　全胚胎培养培养基pH条件改变 (过低或过高 )能够影响培养胚胎的生长发育。植入后全胚胎培养培养基最适pH值为 7.5～ 8.2。     

农药唑呀威毒理及中毒治疗的实验研究

唑呀威（Ｔｒｉａｚｕｒｏｎ）系新型的高效杀蚜虫剂。目前，对其抑制胆碱酯酶活性的毒理尚报道不一。作者在进行毒性测试和发现１６名包装工夏季作业时８名出现明显症状的基础上，开展动物实验研究。结果发现，唑呀威有较有机磷农药更为快速的胆碱酯酶抑制作用，大鼠经口染毒１１２．５ｍｇ／ｋｇ仅３０ｍｉｎ内即见全血胆碱酯酶活性显著下降，Ｐ＜０．０１；且存在明显剂量－反应关系。高剂量（２００ｍｇ／ｋｇ）还可引起心血管系统的损害。注射阿托品有显著解救效果，染毒同时给药的解救效果明显优于染毒后５分钟给药，提示愈早给药解救效果愈好。作者由此提出了临床中毒急救措施的建议     

环孢素A体外抗曼氏血吸虫作用的观察

ＭＦ１小鼠实验感染曼氏血吸虫尾蚴１周、３周和６周后，分别经肺静脉和门静脉灌注取虫。实验显示，药物体外抗曼氏血吸虫的作用呈时间、剂量和虫龄依赖方式，童虫和雄虫对药物更敏感。