Activity of lateral vestibular nucleus neurons during locomotion in the decerebrate Guinea pig

Summary The influence of locomotor activity upon neurons in the lateral vestibular nucleus was investigated in precollicularly-postmamillary decerebrate guinea pigs. Out of 95 recorded neurons, 24 were identified as vestibulospinal and 71 had no descending projections. Locomotor activity occurred either spontaneously or was prompted by electrical stimulation of the mesencephalic locomotor region. Natural vestibular stimulation was supplied by tilting the animal about its longitudinal axis. Locomotor rhythmic limb muscle activity was accompanied by an increase in the firing frequency in the vast majority of investigated neurons. The increase in frequency was observed at the beginning of ipsilateral forelimb extensor muscle activity. Only in a few non-vestibulospinal neurons was the spontaneous activity depressed during locomotion. An increase in evoked responses was observed in almost all vestibulospinal neurons and in two thirds of the neurons without descending projections. A decrease in evoked responses was observed in one quarter of non-vestibulospinal neurons. During locomotion, the mean and maximal frequencies of evoked neuronal impulse activity changed, but the phase lag of these changes was not altered significantly. The results suggest an enhancement of vestibulospinal influences during locomotion, thus providing a high level of tonus in antigravitational muscles. This is interpreted as a mechanism to ensure that equilibrium is maintained during motion in different gaits and postures.     

Effects of androgens and estrogens on the vasopressin and oxytocin innervation of the adult rat brain

Recently we reported that castration of rats eliminates vasopressin immunoreactivity in the lateral septum and other areas that appear to receive vasopressin innervation from the bed nucleus of the stria terminalis. Testosterone treatment counteracts this effect of castration. In the present study, we investigated whether this action of testosterone depends on its androgenic or estrogenic metabolites by treating long-term castrated rats with estradiol (E) and/or 5 alpha-dihydrotestosterone (DHT) or testosterone. The brains were then processed for immunocytochemistry or radioimmunoassay. DHT did not increase vasopressin staining in the lateral septum, although it fully restored the size of the seminal vesicles. E did restore the original fiber density, but individual fibers stained more weakly than in sham-operated males. Only treatment with both E and DHT fully restored the vasopressin innervation. This pattern was also reflected in the radioimmunoassay data. The vasopressin content of the lateral septum decreased about 90% after castration but was fully restored by either testosterone or E + DHT treatment. E alone, however, was only half as effective as E + DHT. The treatments had no effect on the oxytocin content of the septum, or on the vasopressin or oxytocin content of the dorsal vagal complex. The results suggest that E mediates most of the effects of testosterone on the vasopressin innervation of the lateral septum. DHT enhances the response to E but has little effect on its own.     

Development of phantom for radiographic image optimization of standard patient in the lateral view of chest and skull examination

We present the construction of a homogeneous phantom to be used in simulating the scattering and absorption of X-rays by a standard patient chest and skull when irradiated laterally. This phantom consisted of lucite and aluminium plates with their thickness determined by a tomographic exploratory method applied to the anthropomorphic phantom. Using this phantom, an optimized radiographic technique was established for chest and skull of standard sized patient in lateral view. Images generated with this optimized technique demonstrated improved image quality and reduced radiation doses.     

Anatomy and pathophysiology of the popliteal tendon area in the lateral meniscus: 1. Arthroscopic and anatomical investigation

An arthroscopic and anatomical investigation was performed to define the abnormal conditions of the popliteal tendon area in a lateral meniscus. Arthroscopic findings for 100 patients and anatomical observations of 10 amputated knees were analyzed. Five of the 10 dissected menisci were also examined histologically. Menisco-tibial coronary ligaments were classified into two types, as follows: type I--a coronary ligament covering an entire popliteal tendon beneath the meniscus; type II--a popliteal tendon visible beneath the meniscus through defects of the coronary ligament. Twenty-one of 100 cases were classified as type I, and 79 were classified as type II. Three of the 10 anatomical dissections were type I, and the remaining 7 were type II. Menisci in which the type I coronary ligaments were thought to be torn and menisci with type II coronary ligaments showed a rather marked mobility, but no conclusion could be reached.     

Lateral unicompartimental knee arthroplasty: indications,technique and short-medium term results

Lateral unicompartmental knee arthroplasty (UKA) is a valid alternative treatment in the event of arthritis confined to the lateral compartment. This paper examines its indications, technique and short to medium-term results. A total of 159 Miller–Galante cemented UKA prostheses (Zimmer, Warsaw, Indiana) were implanted consecutively (131 medial and 28 lateral) by the same surgeon. This study investigates 28 lateral UKAs in 27 patients. Twenty-five implants in 24 patients (including a subject operated bilaterally) were followed up for 12–60 months. Three patients were discarded on account of to short a follow-up period. The Hospital for Special Surgery (HSS) knee score was used to compare the pre- and post-operative results of the lateral UKA patients. The HSS score improved from a pre-op mean of 59.92 (range 48–68) to 88.04 (range 71–95) at the last follow-up. There was a positive increase in the pain, function and ROM components of the score. The lateral UKA prosthesis can be regarded as a sound alternative to total knee replacement. Correct patient selection on the basis of optimum surgical indications, however, is essential. No benefits of funds were received in support of the study.     

颈椎肿瘤单侧关节突关节切除后的稳定性重建

目的：探讨颈椎肿瘤单侧关节突关节切除后稳定性重建的方法及效果。方法：对1999—2005年存我院骨科手术治疗且得到随访的18例切除单侧关节突关节的颈椎肿瘤患者的资料进行分析，男10例，女8例；年龄16～72岁，平均46岁。神经根受压表现为主者10例，VAS评分2～8分，平均4．2分；脊髓压迫表现为主者8例．ASIA分级C级5例．D级3例。均采用颈后路患侧关节突关节、侧块切除，完整切除肿瘤组织，其中10例行单侧侧块钢板固定植骨融合，8例行双侧侧块钢板固定植骨融合。结果：随访3—60个月，平均20个月，1例透明细胞癌肺转移患者死亡．余存活无复发。10例神经根受压表现为主者术后疼痛VAS评分0—4分，平均1．6分。8例脊髓压迫表现为主者，5例术前C级者术后C级2例、E级3例，3例术前D级者术后D级2例．E级l例。双侧侧块钢板固定植骨融合者术后3个月4例m现骨性融合（其中1例3个月后失访），6个月7例达到骨性融合，内固定无断裂、松动、移位。无颈椎不稳。单侧侧块钢板固定植骨融合者．1例术后5个月出现颈部疼痛；9例在术后9个月骨性融合；1例12个月时仍未能骨性融合，螺钉松动。结论：颈后路侧块钢板同定植骨融合可以实现颈椎肿瘤单侧关节突关节切除后的颈椎稳定性重建。     

踝关节侧副韧带损伤的超声表现

目的 分析踝关节侧副韧带损伤的超声图像特征并评价其诊断价值。方法 采用7～13MHz线阵探头探查136例临床怀疑踝关节侧副韧带损伤患者，观察胫舟、胫距前、胫跟、距腓前、跟腓、胫距后、距腓后韧带，共计952条韧带，其中，51例的超声结果与手术比较。结果 46例侧副韧带完全及部分撕裂伤的超声诊断与手术结果符合。侧副韧带挫伤以肿胀为主，部分撕裂伤超声表现为韧带局部连续性中断（跟腓韧带）和不规则低-无回声区内见丝状结构相连，完全撕裂伤超声表现为韧带连续性中断，断端挛缩（跟腓韧带）和不规则低-无回声区贯穿整条韧带，无明显断端挛缩征。结论 高频超声对踝关节侧副韧带损伤的诊断无创、较准确、廉价，具有较高的临床应用价值。     

膝关节后外侧结构的解剖与MRI研究

目的 改进膝关节后外侧结构MRI定位方法，提高后外侧结构损伤的诊断准确率。方法 解剖膝关节标本，辨认后外侧各结构起止点及走行，明确它们之间的解剖关系。以注水的输液器缝合标记各结构进行MRI扫描，测量各结构在矢状面和冠状面上与腓骨颈长轴之间的夹角。按照这些角度定位扫描正常膝关节，观察各结构在MRI中完整显示的情况。结果 （1）测得矢状面上腓侧副韧带和胴肌腱关节囊内部分与腓骨颈长轴的夹角分别为（11．5±1.7）°和（39．5±6，4）°冠状面上胴肌腱关节囊外部分和胴腓韧带与腓骨颈长轴夹角为（39.5±3．9）°和（31．9±3．9）°。（2）腓侧副韧带在11°后斜冠状位1个层面上完整显示占90％，胴肌腱关节囊内部分在40°后斜冠状位1个层面上完整显示占80％，胭肌腱关节囊外部分在内斜40°矢状位1个层面上完整显示占90％，胭腓韧带在外斜30°矢状位1个层面上完整显示占90％。此外，胴腓韧带在11°后斜冠状位1个层面上完整显示的占75％，股二头肌腱和髂胫束在常规冠状面均能够很好显示.结论 选择完整显示腓骨茎突和腓骨颈的冠状面和矢状面为基准面，按照后外侧各结构与腓骨颈长轴所呈角度进行定位，层厚2mm的MR扫描能很好地显示膝关节后外侧解剖结构。     

侧脑室－头静脉分流术治疗梗阻性脑积水

通过对２５例成人尸体的解剖学调查及应用＂侧脑室─头静脉分流术＂治疗２３例梗阻性脑积水的临床疗效观察，旨在确立一种脑积水症手术分流的新途径。２３例手术病人显效率９２％（２１／２３）。１８例（７８％）基本恢复正常。３例（１３％）明显好转。２例轻度改善。分析表明：头静脉具备位置浅表恒定、管径适宜、瓣膜可防止血液返流等解剖学特点。是一条可供选择的较为理想的脑积水症分流途径。     

The lateral arm free flap in lower extremity reconstruction

Reconstruction of skin defects of the distal third of the leg and foot is often a difficult task. Shape, resistance to shearing stresses in the weight-bearing surface and sensibility are the main features that have to be restored. For coverage of this region, the authors have used, in selected patients, the lateral arm flap (LAF) since 1994. This flap is thin, easy to dissect and has the possibility to be innervated through the posterior cutaneous nerve of the arm. Fourteen cases are presented. The drawbacks of this flap are the loss of sensibility in the forearm (partially transient) and the scar on the arm, which can be rather unsightly in young ladies and when big flaps are harvested skin graft is needed.