人工髓核置换治疗腰椎间盘突出症初步报告

目的探讨人工髓核置换治疗腰椎间盘突出症临床应用的初步效果. 方法自2002年5月～2003年8月行单个人工髓核假体(PDN)置换术治疗腰椎间盘突出症26例. 结果所有病例均获随访,平均时间10.5(3～18)个月.临床疗效评价:优18例,良4例,尚可2例.1例发生椎间隙感染,保守治疗后好转;1例术后2月出现假体移位、症状复发,行再次手术更换假体后治愈. 结论人工髓核假体置换治疗腰椎间盘突出症能恢复椎间隙高度,操作简单,创伤小,恢复快,近期疗效满意,远期疗效仍需进一步观察.     

对侧网状巨细胞核对大鼠脊髓背表面电位的影响

以浅麻醉和麻痹大鼠为对象,利用计算机平均技术记录强电流刺激腓肠神经诱发的脊髓背表面电位(CDP),观察对侧网状三细胞核(NGC)微量注射L一谷氨酸钠,使神经细胞兴奋后对CDP的影响.实验发现,对侧NGC神经细胞兴奋后,Aβ和Aσ纤维引起的P_1波及Aσ和C类纤维引起的N_3波减小,C类纤维引起的P_2波明显减小,N_4 波消失.以上结果提示:对侧NGC对细纤维诱发的CDP成分有抑制作用.     

Vasopressin receptors in the mouse (Mus musculus) brain: sex-related expression in the medial preoptic area and hypothalamus

We have investigated the distribution of vasopressin binding sites in the brain of male and female adult mice using a radio-iodinated ligand and film autoradiography. Vasopressin receptors were uncovered in various regions of the brain including the basal nucleus of Meynert, the substantia innominata, the hypothalamic paraventricular nucleus, the substantia nigra pars compacta and the hypoglossal nucleus. A sex-related difference in the expression of vasopressin receptors was seen in the medial preoptic area/anterior hypothalamus corresponding to the rat sexually dimorphic nucleus in the rat and in the hypothalamic mammillary nuclei. In both structures the autoradiographic labeling is more intense in females than in males. These observations confirm that vasopressin binding sites are present in the hypothalamic preoptic area of most species examined so far and that sex-related expression of neuropeptide receptors could trigger sex-related behavioral differences.     

Chemosensitivity of neurons in the dorsal motor nucleus of the vagus that responded to portal infusion of hypertonic saline in rats

Neural responses in the dorsal motor nucleus of the vagus (DMV) to topical administrations of sodium and portal infusions of hypertonic saline were investigated electrophysiologically by using multibarrel electrodes in anesthetized rats. Of 102 neurons that showed antidromic response to electrical stimulation of the ventral gastric vagus or the accessory celiac vagus, 51 neurons increased and 13 neurons decreased their discharge rates in response to the electrophoretic administration of sodium. The other 38 neurons did not respond to this stimulation. The portal infusion of hypertonic saline elicited neural responses of some DMV neurons whose axons are involved into either the ventral gastric or the accessory celiac vagus. Further, effects of the topical administration and the portal infusion of hypertonic saline were examined on 33 neurons. Typical response was characterized by an increase in discharge rate responding to both of the portal infusion and the topical administration. In conclusion, the DMV neurons receiving the afferent inputs from hepatoportal osmoreceptors may have an enteroceptor function detecting the change in osmotic pressure of their environment.     

Calretinin is differentially localized in magnocellular oxytocin neurons of the rat hypothalamus. A double-labeling immunofluorescence study

By use of a double-labeling immunofluorescence method with a confocal laser scanning microscope, we have examined whether a calcium-binding protein, calretinin, is localized in magnocellular oxytocin and vasopressin neurons of the rat hypothalamus. In the supraoptic nucleus, all oxytocin-labeled cells were stained for calretinin. However, in the magnocellular part of the paraventricular nucleus, almost all oxytocin-stained cells were devoid of calretinin immunoreactivity. All vasopressin-positive cells of both the supraoptic nucleus and the magnocellular part of the paraventricular nucleus lacked calretinin immunoreactivity. No calretinin immunoreactivity was found in oxytocin-labeled cells of the the anterior commissural nucleus or in vasopressin-labeled cells of the suprachiasmatic nucleus. We previously showed that another calcium-binding protein, calbindin-D28k, was localized in magnocellular oxytocin neurons of the supraoptic nucleus but not in those of the paraventricular nucleus. These findings suggest that, in general, magnocellular oxytocin neurons of the supraoptic nucleus and those of the paraventricular nucleus can be chemically distinguished, that is, the former contain both calretinin and calbindin-D28k but the latter lack the two calcium-binding proteins.     

Release of vasopressin from supraoptic neurons within the median eminence in vivo. A combined microdialysis and push-pull perfusion study in the rat

The present study was designed to investigate whether or not arginine vasopressin (AVP) is released from magnocellular neurons within the median eminence (ME) in vivo. Urethane-anesthetized adult male Wistar rats were equipped with a microdialysis probe aimed at the supraoptic (SON) or paraventricular nucleus (PVN), a push-pull perfusion probe resting in the ME, and a blood microdialysis probe within the jugular vein. Dialysis of the SON (but not the PVN) with Ringer's solution containing 56 mmol l⁻¹ K⁺ resulted in an increase in AVP release within the ME (to 492 ± 192% of release during basal conditions,P < 0.05) and into blood (to 138 ± 9%,P < 0.01) whereby the release probably occurred from axonal swellings and nerve terminals of supraoptic neurons which project through the internal zone of the ME to the posterior pituitary. The calculated amount of AVP released into the extracellular fluid of the ME was high enough (approximately 1 pg/μ1) to hypothesize that the neuropeptide could enter the portal blood capillaries in physiologically relevant concentrations. Taken together, the present study indicates that activation of magnocellular neurons is accompanied by release of AVP within the median eminence. We assume that AVP released in this way might mediate a communication between the hypothalamic-neurohypophysial system and the hypothalamic-pituitary-adrenal axis in response to selected stressful stimuli.     

Neuronal changes in the basolateral complex during development of the amygdala of the rat

Neuronal changes in the amygdala basolateral complex were studied during development and maturation in fetal and postnatal rat brains using morphometrical methods. Forty brains of animals of various ages were fixed in formalin, frozen and cut into 25 μm thick sections and stained with cresyl violet or haematoxylin and eosin (H&E). In cresyl violet preparations, the complex appeared for the first time on embryonic day (E)17 and was composed of two homogeneous nuclei—lateral and basolateral. On about the seventh postnatal day, each of these nuclei was divided into two parts—the first one into the dorsolateral and ventromedial and the second one into the anterior and posterior. Morphometric investigations showed a different increase of the neuronal and nuclear size in various parts of the basolateral complex up to postnatal day (P)14; after that time these parameters did not change significantly. The neuronal density and the total number of neurons stabilized at P7 in all parts of this complex, except for the dorsolateral part of the lateral nucleus in which a 30% decrease of the total number of cells was observed. From P14, in all nuclei under study, the total number of neurons did not change significantly.     

东莨菪碱对大鼠下丘脑室旁核精氨酸升压素的影响

目的 观察东莨菪碱对大鼠下丘脑室核精氨酸升压素的影响。方法 以不同浓度Ｓｃｏｐ推挽灌流大鼠下丘脑室旁核 结果 扣留出液中精氨酸升压素含量随推挽时间延长而增多。结论Ｓｃｏｐ可促进ＰＶＮ释放内源性ＡＶＰ，这对了解Ｓｃｏｐ抗休克的机理有重大的意义。