大鼠内脏大神经电刺激后C－Fos在中枢神经系统中的表达

有关内脏痛的问题,已有不少学者进行了研究。但由于内脏痛本身的复杂性,至今其中枢传导途径还不太清楚。本实验刺激大鼠内脏大神经后,利用Ｆｏｓ的免疫组化技术在下列结构中可以发现Ｆｏｓ免疫组化阳性反应的神经元：隔外侧核、斜角带核、丘脑的菱形核、连接核、下丘脑室旁核、中缝背核、兰斑、中缝大核、网状外侧核、脊髓ＲｅｘｅｄⅠⅡⅢⅩ层等结构。而在对照组的上述结构中没有表达,只在耳蜗背核有较明显的表达。通过上述研究我们发现围绕脊髓中央管和各脑室的周围灰质系统与内脏伤害性刺激有关。这引起了我们极大的兴趣。关于这部分的工作我们正在进行中。     

Nerve growth factor: structure/function relationships.

Nerve growth factor (NGF), which has a tertiary structure based on a cluster of 3 cystine disulfides and 2 very extended, but distorted beta-hairpins, is the prototype of a larger family of neurotrophins. Prior to the availability of cloning techniques, the mouse submandibular gland was the richest source of NGF and provided sufficient material to enable its biochemical characterization. It binds as a dimer to at least 2 cell-surface receptor types expressed in a variety of neuronal and non-neuronal cells. Residues involved in these interactions and in the maintenance of tertiary and quaternary structure have been identified by chemical modification and site-directed mutagenesis, and this information can be related to their location in the 3-dimensional structure. For example, interactions between aromatic residues contribute to the stability of the NGF dimer, and specific surface lysine residues participate in receptor contacts. The conclusion from these studies is that receptor interactions involve broad surface regions, which may be composed of residues from both promoters in the dimer.     

Galanin and vasoactive intestinal peptide messenger RNAs increase following axotomy of adult sympathetic neurons

The adult rat superior cervical ganglion (SSG) contains low levels of galanin- and vasoactive intestinal peptide-(VIP) like immunoreactivity, with very few immuno-stained principal neurons. Immunoreactivity for both neuropeptides increases in these neurons after explanation or postganglionic axotomy in vivo. Northern blot analysis had demonstrated concomitant increases in mRNAs encoding these peptides. To localize cells in axotomized ganglia which increase their expression of these mRNAs, we performed in situ hybridization studies. In control SCG, only a few principal neurons contained mRNA for either galanin or VIP. After 48 h in organ culture, galanin mRNA was expressed in the majority of principal neurons. At 48 h after in vivo axotomy of both postganglionic trunks of the SCG, the internal and external carotid nerves, the distribution and number of neurons expressing galanin mRNA increased similarly to that seen in culture. Lesioning either trunk alone produced increases in galanin mRNA localized to those regions of the ganglion containing neurons that project into the lesioned trunk. Transection of the predominantly preganglionic cervical sympathetic trunk increased galanin mRNA expression in a small population of neurons that nerve trunk. The distributions of these labeled neurons, together with previous neuroanatomical studies, suggests that they had been axotomised by the lesions. Similar studies examining VIP mRNA expression demonstrated that although considerably fewer VIP mRNA expressing neurons than galanin mRNA expressing neurons were present after axotomy, the distribution of neuropeptide mRNA-positive cells were similar in both cases. These observations suggest that increases in the peptide galanin and VIP after nerve transection result from changes in the levels of their mRNAs in those neurons that have been axotomized. 1994 John Wiley & Sons, Inc.     

Retrograde determination of motoneuron properties and their synaptic input

Both motoneurons and the muscle fibers that they innervate can vary widely in their properties. The finding that these properties are highly correlated indicates that these cells are not specified independently, but rather interact in some manner to achieve the observed coherence. The direction of the interaction, i.e., whether orthograde or retrograde, required analysis beyond the simple observation of these correlated properties. Evidence, largely from experiments involving reinnervation of muscle by the original or a foreign motor nerve, suggests the action of retrogradely transported factors from the muscle as well as orthograde ones. Various possible factors, specifically neurotrophins, are advanced as possible candidates for retrograde specification. In addition, synaptic input to motoneurons also varies in a coordianted fashion in a manner that suggests a retrograde determination from the muscle. However, motoneuron properties and their synaptic input change after peipheral nerve manipulations such that they are no longer in register. This indicates some independence in retrograde specification of motoneurons and their synaptic input. 1994 John Wiley & Sons, Inc.     

Cell adhesion molecules in the early developing mouse retina: Retinal neurons show preferential outgrowth in vitro on L1 but not N-CAM

Both L1 and N-CAM are present on optic axons early in the developing mouse retina and optic nerve. In in vitro assays on substrates of purified cell adhesion molecules cells derived from E13 mouse retinae showed vigorous neurite extension on L1 but not on N-CAM. Although retinal neurons on N-CAM showed only limited attachment to the substrate, they were able to form lamellipodia immediately around the cell perimeter. In contrast, similarly derived cortical cells showed extensive neurite outgrowth on both substrates. Under these culture conditions, nearly all of the L1 and N-CAM present in the cell membrane appeared to be sequestered on the lower surface of the growth cones and neurites, indicating that most of these cell adhesion molecules were involved in homophilic interactions. Our results suggest differential roles for L1 and N-CAM in intitiation and establishment of the optic pathway. © 1994 John Wiley & Sons, Inc.     

髋部肌锻炼联合盆底电刺激生物反馈对盆底功能障碍性疾病患者盆底功能及应激反应的影响

摘要 目的：探讨髋部肌锻炼联合盆底电刺激生物反馈对盆底功能障碍性疾病（PFD）患者盆底功能及应激反应的影响。方法：选取2021年1月-2022年12月在我院接受治疗的120例PFD患者作为研究对象,按随机数字表法分为对照组和观察组,每组各60例。对照组患者进行髋部肌锻炼,观察组患者在对照组的基础上联合盆底电刺激生物反馈治疗,观察分析两组患者盆底功能以及应激反应的变化。结果：两组治疗后观察组临床总有效率显著高于对照组（P＜0.05）;两组患者治疗后PFDI-20、PISQ-12及PFIQ-7评分显著优于治疗前,且观察组上述指标明显优于对照组（P＜0.05）;治疗后两组患者前盆底肌电位、动态肌张力、静态肌张力及收缩力较治疗前显著改善,且观察组相较于对照组上述指标显著提升（P＜0.05）;治疗后两组患者去甲肾上腺素（NE）、前列腺素（PGE₂）、皮质醇（COR）水平明显提高,且观察组明显优于对照组（P＜0.05）。结论：髋部肌锻炼联合盆底电刺激生物反馈使肌肉功能得到锻炼,提高了盆底肌张力水平,促进盆底功能的恢复和应激反应的提高,明显提高患者的生活质量。     

实时三维盆底超声对产后压力性尿失禁患者疗效评估作用及与尿动力学的相关性分析

摘要 目的：探讨实时三维盆底超声对产后压力性尿失禁（SUI）患者疗效评估作用及与尿动力学的相关性。方法：选择2020年4月至2022年12月石家庄市人民医院收治的139例产后SUI患者,均接受盆底生物反馈电刺激联合盆底肌锻炼治疗。治疗前后分别进行实时三维盆底超声检查和尿动力学检查。比较治疗前后实时三维盆底超声参数、尿动力学指标差异。Pearson法分析实时三维盆底超声参数与尿动力学指标的相关性。结果：实时三维盆底超声图像特征显示：治疗前盆膈裂孔内的结构疏松,回声变弱,盆腔器官结缔组织疏松,间隙增宽,盆膈裂孔面积、尿道旋转角、膀胱尿道后角以及膀胱颈移动度较大;治疗后盆膈裂孔两侧耻骨直肠肌对称,耻骨内脏肌呈带状高回声,盆膈裂孔面积、尿道旋转角、膀胱尿道后角以及膀胱颈移动度较治疗前降低。产后SUI患者治疗后静息状态和Valsalva状态下盆膈裂孔面积、尿道旋转角、膀胱尿道后角、膀胱颈移动度均较治疗前降低（P＜0.05）,腹压漏尿点压、最大逼尿肌压力均较治疗前增加（P＜0.05）。产后SUI患者静息状态和Valsalva状态下盆膈裂孔面积、尿道旋转角、膀胱尿道后角、膀胱颈移动度与最大逼尿肌压力、腹压漏尿点压呈负相关（P＜0.05）,与最大膀胱容量和残余尿量无关（P＞0.05）。结论：产后SUI患者经盆底生物反馈电刺激联合盆底肌锻炼治疗后实时三维盆底超声参数较治疗前降低,与尿动力学改善有关。临床可通过实时三维盆底超声检查,对产后SUI患者进行临床疗效评价,以指导临床治疗。     

苦参碱对神经病理性大鼠背根神经节P2X3受体、疼痛行为学和疼痛阈值的影响

摘要 目的：探讨苦参碱对神经病理性大鼠背根神经节P2X3受体、疼痛行为学和疼痛阈值的影响。方法：选择Sprague-Dawley雄性大鼠30只,随机分为3组,包括模型组、试验组和假手术组。于大鼠造模成功1 d后,试验组给予30 mg/（kgod）的剂量在腹腔注射苦参碱溶液,1次/d;给予假手术组和模型组腹腔注射等量浓度为0.9 %的氯化钠溶液,1次/d,共14 d。进行自发疼痛行为学评分检测、机械痛阈值检测、热痛阈值检测、P2X2和P2X3mRNA相对表达量检测、P2X2和P2X3蛋白表达水平检测,以及氧化应激指标水平检测。结果：术后模型组与试验组自发性疼痛行为学评分与假手术组比均升高,自术后第5天起,与模型组比,试验组自发性疼痛行为学评分明显低于模型组（P<0.05）;自术后第3天起,相较于假手术组,模型组机械痛阈值、热痛阈值显著下降,相较于模型组,试验组自术后第5天起机械痛阈值、热痛阈值显著上升（均P<0.05）;术后第14天试验组与假手术组机械痛阈值、热痛阈值对比无差异（P>0.05）;模型组P2X2和P2X3mRNA、P2X2及P2X3蛋白比假手术组和试验组高（均P<0.05）,试验组和假手术组P2X2、P2X3mRNA、P2X2及P2X3蛋白比较无差异（P>0.05）;干预前及干预1、2周后模型组大鼠脊髓组织SOD比假手术组低,MDA比假手术组高;试验组大鼠脊髓组织SOD比模型组高,MDA比模型组低（均P<0.05）。结论：苦参碱可有效缓解神经病理性痛的所引发的机械痛觉和热痛觉,镇痛作用较好,机制可能在于其可使大鼠背根神经元中P2X2、P2X3受体下降相关,同时其在抑制神经病理性大鼠脊髓组织氧化应激反应方面有一定的作用,与其在对神经病理性痛大鼠脊髓组织神经元凋亡的抑制有密切关系。     

Structural and functional heterogeneity of single-stranded DNA-binding proteins from calf thymus

A new purification technique for ‘single-stranded DNA-binding proteins’ from calf thymus permits the demonstration of a considerable heterogeneity within these proteins. Several molecular species are obtained with M_r between 24·10³ and 30·10³ and pI values between 6 and 8, showing significant differences with regard to the following functional properties: (1) strength of binding to single-stranded DNA; (2) lowering of melting temperature of poly[d(A-T)]; (3) stimulation of DNA polymerase α on a poly[d(A-T)] template. Analysis of trypsin digestion products demonstrates that the different molecular species share extensive primary sequence homology. Experiments with antibodies show that the different molecular species are antigenically related and that a 31 kDa protein present in low amounts in our preparations is very cross-reactive.     

Pressure dependence of sodium gating currents in the squid giant axon

Asymmetric displacement currents, I_g, were measured in squid axons at different hydrostatic pressures, P, up to 60 MPa. Potassium and sodium currents were abolished by intracellular Cs⁺ and TEA⁺, by extracellular Tetrodotoxin (TTX), and by Na⁺ substitution with Tris⁺. The time course of Ig became progressively slower with increasing pressure, and the amplitude decreased. With appropriate scaling in time and amplitude, I_g records at any given P could be made to superimpose very well with those obtained at atmospheric pressure. The same scaling factors yielded a good superposition of all records obtained for voltage steps to membrane potentials in the range-30 to +42 mV. The ratio between the amplitude and time factors was larger than unity and increased with P, indicating a progressive decrease (up to 35% at 60 MPa) of the total charge displaced, Q, with no significant change in its voltage dependence. The time-scaling factor increased exponentially with P, as expected if all the steps involved in the opening of a sodium channel, and producing a major charge redistribution, have the same activation volume, V _g 17 cm³/mol. This value is roughly one-half of that characterizing the pressure dependence of sodium current activation, suggesting that some late, rate-limiting step in the opening of sodium channels has a large activation volume without being accompanied by an easily detected charge movement.Part of the decrease of Q with pressure could be attributed to an increase in sodium inactivation. However, we cannot exclude the possibility that there is a reversible reduction in the number of fast activating sodium channels, similar to the phenomenon that has been reported to occur at low temperatures (Matteson and Armstrong 1982).