Neural plasticity in vivo: opioid sensitivity of memory develops gradually after a septal lesion

Neuronal plasticity can manifest itself in alterations in the sensitivity of memory to the effects of drugs. After the production of a brain lesion, the memory processing of a passive-avoidance task in mice gradually becomes sensitive to the effect of morphine, i.e., an improvement in retention performance is seen after 6 weeks, but not after 1 or 2 weeks. The results presented demonstrate that, even if they lead to no discernible changes in behaviour, plastic processes can still be detected by means of behavioural tests.     

多曲方丝对下颌中切牙牙周膜应力分布有限元分析

目的:对多曲方丝弓技术中打开咬合所产生的力学系统进行有限元分析,了解多曲方丝弓打开咬合时下颌中切牙牙周膜应力分布情况。方法:建立下颌牙列各牙齿、牙槽骨及切牙牙周膜的有限元模型。然后进一步模拟临床在中切牙处加载75g垂直向下的力,按照考虑或不考虑牙周膜的两种情况,求得牙周膜的应力分布。结果:两种情况下牙周膜部位最大值变化很大。在不考虑牙周膜时,牙根颈部应力最大值达21.6×105g/mm2;考虑牙周膜的缓冲作用时牙根及牙周膜上的应力分布相对均匀,且绝对值变小,但牙槽嵴顶部应力峰值明显变大。结论:①本研究建立的下颌牙列的三维有限元模型,比较符合实际情况,可以适用于多曲方丝弓矫治技术的研究。②多曲方丝弓作用下下颌中切牙牙周膜应力从颈缘到根尖逐渐减小,但在牙槽嵴顶部应力峰值明显增大,易出现牙周膜透明性变。     

易误诊为神经肿瘤的一种疾病——肿块型中枢神经系统原发性血管炎

背景与目的：由于缺乏特异性临床和影像表现，肿块型中枢神经系统原发性血管炎（primary angiitris of central nervous system，PACNS）常被误诊为胶质瘤．本文旨在探讨肿块型PACNS的诊断与鉴别诊断。方法：回顾性分析手术治疗的37例肿块型PACNS患者的临床及影像表现。结果：85．3％的患者出现局灶性神经功能减退，55．9％患者有不同程度皮层高级功能减退症状。70．6％的颅内病变累及脑皮层：73．5％患者的正常区域脑血管周围间隙增宽，其中76％出现血管强化；病变出现特征性的“C”形强化。结论：局灶性神经功能和高级功能减退、病变累及皮层和“C”形强化等特征．有助于诊断肿块型PACNS。     

Carcinoma of the thyroid in black patients.

In the period from January 1, 1976 to December 31, 1988, we reviewed the charts of 33 patients treated for carcinoma of the thyroid at Howard University Hospital. The three non-black patients (two Whites and one Pakistani) were excluded from the study. There were 19 females and 11 males. Of the 30 cases elevated, 10 were papillary, 7 were follicular variant of papillary, 8 were follicular, 3 were undifferentiated (anaplastic), and 2 were medullary. Ten patients had either distant metastasis (Hoffman, South Med J 80:741, 1987) or locally advanced disease in the neck (Woolner et al., Am J Surg 102:354, 1961.) at the time of diagnosis. The treatment of these lesions depended on, among other variables, the cell type, the extent of the lesion, and the personal preference of the attending surgeon. Carcinoma of the thyroid remains an uncommon lesion in Black patients. Because of its rarity, the diagnosis may often be delayed and, as a result, patients may first come to attention with a more advanced stage of this disease. To prevent this occurrence, a high index of suspicion must be maintained for all thyroid nodules, and appropriate diagnostic steps taken. Diagnostic and treatment options are discussed.     

慢性脊髓损伤的实验研究

探讨慢性脊髓损伤的形成原因。方法 选用新西兰白兔36只，随机分为6组，即1天、4月、8月造模组及相应对照组，造模组使用自制捆绑法固定兔于腰椎弯曲位来模仿人类的弯腰运动，通过体感皮层诱发电位及组织形态学等技术进行动态观察。结果 4、8月组造模动物白质出现了髓鞘变薄、水肿，粗大轴突的数量减少，细小的轴突相对增多，诱发电位潜伏期延长等慢性脊髓损伤的病理变化。结论 压迫和牵拉都是造成慢性脊髓损伤的原因。     

Fracture separation of the articular pillar of C5 following brass knuckles trauma

We report the case of a fracture separation of the articular pillar at the lower cervical spine. The trauma, following a brass knuckles, repeats almost in an experimental way the rotation and extension mechanism given in literature for the genesis of such injuries. From the admission in the orthopaedic service to the surgery, the development went in a characteristic way towards a rotatory displacement. Received: 12 July 2002, Accepted: 18 August 2002 Correspondence to: R. Massicot     

成年男性下颌角间宽与颧弓深度、长度及下颌角厚度的关系

目的：测量下颌角间宽与颧弓深度、颧弓长度及下颌角厚度并进行相关分析，以期在活体上通过测量下颌角间宽来推算颧弓深度、颧弓长度、下颌角厚度，为临床行颜面美容矫治术及复合体的制作提供相关资料。方法：经福尔马林固定、颜面骨正常的成人男性尸体50具，按《人体测量方法》，用游标卡尺直接测量下颌角间宽、左右两侧颧弓深度与长度、下颌角厚度。结果：颧弓深度、颧弓长度、下颌角厚度与下颌角间宽其相关系数分别是，颧弓深度为0．649(P=0．001)，颧弓长度为0．584(P=0．001)，下颌角厚为1．0(P=0．001)，颧弓深度、长度左、右无明显差别。结论：临床采用测量下颌角间宽来推算颧弓深度、颧弓长度及下颌角厚度具有显著性意义。     

钛种植体－羟基磷灰石早期修复犬下颌骨缺损与骨结合的实验研究

本研究对钛种植体－羟基磷灰石（Ｔｉ－ＨＡ）在早期修复下颌骨缺损中与骨结合的界面形态进行了扫描电镜和Ｘ线能谱观察分析。通过对９只健康狗下颌骨缺损区植入Ｔｉ－ＨＡ２、６及１２周后Ｔｉ－ＨＡ／宿主骨界面及Ｔｉ／ＨＡ界面的扫描电镜观察和Ｘ线能谱分析，结果表明Ｔｉ－ＨＡ植入骨缺损区，不引起正常的骨矿化过程改变，与宿主骨形成骨性结合；Ｔｉ／ＨＡ界面有新骨形成；扫描电镜观察和Ｘ线能谱分析在研究骨缺损修复过程中不同阶段的组织成份的变化是一个重要手段。     

Intrahippocampal Injection of Endothelin-1: A New Model of Ischemia-induced Seizures in Immature Rats

Summary:  The goal of this study was to develop a new model of ischemia-induced seizures in immature rats using injection of vasoconstrictor Endothelin-1 (ET-1) into the brain. ET-1 (10, 20, or 40 pmol) was infused into the left dorsal hippocampus of freely moving Wistar rats 12 (P12) and 25 (P25) days old. Animals were then video/EEG-monitored for 100 min and monitoring was repeated 22 h later. Parameters of electrographic seizures (frequency and mean duration) as well as pattern of their behavioral correlates were evaluated. The pattern of behavioral seizures was used to develop model-specific scoring system. Cresyl violet and Fluoro Jade-B-staining were used to evaluate brain damage. Extension of the lesion was correlated with seizure severity. After ET-1-injection, seizures occurred in 83–100% animals of all age-and-dose groups and persisted for 24 h except P12 rats with 10 pmol. There were no differences in average seizure duration (18–40 s) or seizure frequency (3–7 seizures/100 min) among individual dose-groups. Between the 1st and 2nd observation period, total seizure duration decreased in 71% of P12 and 47% of P25 rats. Electrographic seizure activity was most frequently accompanied by clonus, incidence of more severe convulsions (barrel rolling or generalized clonic seizures) increased with dose of ET-1. Morphologic examination did not reveal any dose-related difference in damage severity, hippocampal damage was however more extensive in P12 compared to P25 animals. Seizure severity correlated positively with severity of the damage in both age groups. Our study presents focal injection of ET-1 into the brain as a new and practical model of ischemia-induced seizures in immature rats.     

明显强化孤立肺结节血流模式的临床价值

目的利用4层螺旋CT动态增强技术定量评价不同性质的明显强化孤立肺结节的血流模式并初步评价血管内皮生长因子(VEGF)表达阳性的孤立性肺腺癌血管生成与血流模式定量CT参数的相关性.方法 78例孤立明显强化肺结节(直径≤4 cm,68例恶性,10例活动性炎性),行多层螺旋CT(MSCT)动态增强(以4 ml/s的流率注入对比剂).记录孤立肺结节增强前后各时相的CT值并计算强化值、灌注值,结节-主动脉强化值比.灌注值等于时间-密度曲线最大斜率除以主动脉强化值.其中30例VEGF表达阳性的肺腺癌患者用免疫组织化学测定微血管密度(MVD)并标定VEGF,评价肺腺癌血流模式定量CT参数(强化值、灌注值、结节-主动脉强化值比及平均通过时间)与MVD的相关性.结果恶性结节强化值(35.79±10.76) HU与活动性炎性结节(39.76±4.59) HU差异无显著意义 (t=1.148 , P=0.255).恶性结节的结节-主动脉强化值比(14.27±4.37)%及灌注值(3.02±0.96)ml-1·min-1·kg-1均低于活动性炎性结节(18.51±2.71)%,(6.34±4.39)ml-1·min-1·kg-1 (t=2.978,P=0.004;t=5.590,P<0.0001).VEGF表达阳性的肺腺癌强化值(33.06±13.57)HU、结节-动脉强化值比(14.25±4.92)%及灌注值(2.97 ±0.56) ml-1·kg-1·min-1与MVD(70.15±20.03)条/视野,均呈正相关性(r=0.781, P<0.0001;r=0.688, P<0.0001;r=0.716, P<0.0001).平均通过时间(14.86±5.84)s与MVD无显著相关性(r=0.260, P=0.200).结论恶性与活动性炎性孤立肺结节血流模式不同,恶性结节通过结节-大动脉强化值比和灌注值可有效区别于活动性炎性结节,有助于两者鉴别诊断.肺腺癌强化值、结节-动脉强化值比及灌注值反映了VEGF表达阳性的肺腺癌的MVD.强化值、结节-动脉强化及灌注值可作为VEGF相关的肺腺癌血管生成的指标.