Decrease in the number of lower affinity (type II) nerve growth factor receptors on embryonic sensory neurons does not affect fiber outgrowth

Nerve growth factor binds to two different specific receptors on responsive cells. The relationship of these two receptors is not fully understood at this time. We have studied the binding of labeled NGF to a different strain of white leghorn chicken embryo dorsal root ganglionic cells. The equilibrium dissociation constants for the two sites (K = 4.1 ± 1.8 × 10^?11M, K = 1.0 ± 0.8 × 10^?9M) are identical to those obtained previously. Also, the number of type I sites per cell (3.8 ± 1.3 × 10³) is the same as that previously determined. However, the number of type II sites per cell (1.9 ± 1.3 × 10⁴) is significantly different than that previously determined. This 2.5-fold decrease in the number of type II sites does not affect the concentration of NGF needed to obtain maximal fiber outgrowth from explanted sensory ganglia. The rate of association (1.2 ± 0.2 × 10⁷ M^?1 sec^?1 at 22°C) of labeled NGF with receptors on sensory neurons from this different strain of chickens is identical to that previously obtained. The rate of association of NGF with its receptors on sensory neurons was also determined at 4°C. This rate constant (2.1 ± 1.1 × 10⁶ M^?1 sec^?1) along with the rate constants obtained at 22° and 37°C were used to determine an activation energy for the binding of NGF to its receptors. The activation energy obtained (16.2 kcal/mole) suggests that binding is not a diffusion-controlled process.     

Melorheostosis and the sclerotomes: A radiological correlation

Melorheostosis is characterised radiologically by hyperostotic linear densities in bone. These densities have a peculiarly segmental distribution which does not correspond with the anatomical course of blood vessels or mixed nerve roots of the limbs. So far this distribution has lacked any valid explanation, although it has been suggested to be a developmental error as a result of an embryonic metameric disturbance. Inman and Saunders in 1944 described a sensory nerve supply to skeletal structures with sclerotomes representing the zones of the skeleton supplied by individual spinal sensory nerves. Radiographs of 30 cases from the Radiological Museum of the Institute of Orthopaedics, London, have been reviewed and an attempt has been made to correlate the sclerosing lesions with the sclerotomes. The investigation was handicapped by paucity of films and clinical information, but in 19 cases the skeletal abnormalities were considered to correspond with a single sclerotome or part thereof. These studies were convincing when films of an affected hand or foot were available. In the remaining 11 cases multiple sclerotomes appeared to be involved and the clinical manifestations were correspondingly more severe. It is proposed that melorheostosis may be the late result of a segmental sensory nerve lesion, to account for its sclerodermal distribution. The association with linear scleroderma is discussed, since it has been suggested that these cutaneous lesions are related to the same nerve segment. Eight cases showed para-articular ossification of soft tissues which may be related to involvement of a corresponding myotome.     

Effects of graft placement site on the survival of adrenal medulla transplants into the brain and its relation with the recovery of motor function

BACKGROUND: Because of their lack of long-term viability, adrenal tissue transplants have shown limited success in alleviating the motor disturbances associated with experimental and pathologic striatal dopamine denervation. In this study, we examined how the graft placement site influences adrenal medulla transplant survival and its relation with the reduction of motor deficits in rats bearing unilateral 6-OHDA lesion. METHODS: One or 5 microL of fetal adrenal medullar tissue was grafted either inside the striatal parenchyma or into the lateral ventricle in contact with the dopamine-denervated striatum. Motor disturbances, as assessed by apomorphine-induced rotation, were correlated to the graft morphologic survival features. RESULTS: Apomorphine-induced rotation showed a marginal reduction of 11% in all groups independently of graft survival features or placement site. Intrastriatal transplants showed limited viability characterized by a substantial loss of graft initial volume as well as fewer and smaller chromaffin cells compared to ventricular grafts, which had a reduced loss of graft initial volume and more and larger chromaffin cells. CONCLUSIONS: Although the lateral ventricle may favor adrenal medulla transplant viability, their induced motor outcome is comparable to that induced by less viable intrastriatal grafts, suggesting that the implanted dopamine-producing cells may interact and influence striatal neurons better when placed in close proximity.     

儿童感觉统合失调及其影响因素分析

目的了解儿童感觉统合失调的现况及影响因素.方法采用"儿童感觉统合能力发展评定量表"和自拟的调查问卷对合肥市某小学933名智力正常儿童进行感觉统合评定和影响因素分析.结果儿童感觉统合失调的总发生率为34.7%,男孩发生率(42.3%)明显高于女孩(28.8%)(P＜0.01).单因素和多因素分析表明,感觉统合失调的主要影响因素有母亲文化程度、家庭结构和气氛、父母教育子女的态度和方式、母亲孕前的不良因素、儿童的疾病史和3岁前是否被寄养.结论感觉统合失调的发生是多因素相互作用的结果.     

卒中后抑郁与神经功能缺损及日常生活能力的相关性探讨

目的探讨脑卒中后抑郁发病率与神经功能缺损程度和日常生活能力的关系。方法对198例住院诊断为脑卒中的患者,在发病1个月时用改良的爱丁堡斯堪的那维亚神经功能缺损评分表和日常生活能力量表进行评分,并根据汉密尔顿抑郁量表评定,分卒中后抑郁(post stroke depression,PSD)和非PSD两组。结果卒中后1月时,PSD的发病率在神经功能缺损组中明显高于神经功能正常组;在生活能力依赖组中PSD的发生率明显高于独立生活能力组。结论脑卒中后PSD的发病率在卒中后有神经功能缺损以及日常生活能力需依赖的患者中较高。     

硬膜外自控镇痛技术在脊柱内镜手术中的应用研究

探讨硬膜外自控镇痛在脊柱内镜手术应用的临床效果。选择120例脊柱内镜手术治疗腰椎间盘突出症患者,随机分为对照组(0.2%罗哌卡因+0.2%利多卡因局麻),0.1%罗哌卡因+舒芬太尼组(0.1%罗哌卡因+0.3 μg/mL舒芬太尼硬膜外自控镇痛),0.2%罗哌卡因+舒芬太尼组(0.2%罗哌卡因+0.3 μg/mL舒芬太尼硬膜外自控镇痛),采用视觉模拟(VAS)评分法评估手术中镇痛效果,采用改良Bromage 评分评估术毕运动神经阻滞程度,统计0.1%罗哌卡因+舒芬太尼组和0.2%罗哌卡因+舒芬太尼组自控镇痛泵(PCA)按压次数和用药量。结果显示0.2%罗哌卡因和0.3 μg/mL舒芬太尼硬膜外自控镇痛应用于脊柱内镜手术,可以达到明显的镇痛效果,满足手术需要,又同时保留患者双下肢运动功能,即有“感觉和运动阻滞分离”现象,从而避免脊柱内镜下马尾神经损伤的可能,值得在临床上推广。