阿托品、士的宁对电刺激家兔大脑皮层感觉区影响丘脑束旁核神经元伤害性放电的作用

家兔在清醒箭毒化人工呼吸下,采用玻璃微电极细胞外记录束旁核痛抑制单位的放电活动,观察电刺激大脑皮层感觉区对束旁核痛抑制单位伤害性放电的影响,并探讨皮层刺激效应的机理。 23例实验表明,皮层刺激可解除痛抑制单位的伤害性抑制反应,但可为静脉注射阿托品(0.3～0.5mg/kg)或士的宁(0.2mg/kg)所阻断,其中两例痛抑制单位的自发放电,随皮层每一刺激脉冲可出现一阵短暂的遏止,这种遏止反应不为士的宁所阻断。提示:大脑皮层及皮层下中枢的胆碱能系统和甘氨酸可能参与皮层对丘脑束旁核痛抑制单位伤害性抑制反应的下行调节;而在皮层每一刺激遏止一阵痛抑制单位的自发放电活动中,甘氨酸可能不占重要地位。     

三种拟胆碱药对兔中枢作用的比较

给兔icv毛果芸香碱,出现抽搐、流涎、咀嚼,脑电呈低幅快波,呼吸兴奋,icv槟榔碱,兔轻度抽搐、流涎,脑电呈双相反应,呼吸兴奋作用短暂;icv氨甲酰甲胆碱,兔亦出现抽搐、流涎、咀嚼及脑电低幅快波反应,但呼吸变化不一,或为加快,或为减慢。提示三种拟胆碱药中枢作用不完全相同,其原因可能与选择性激动中枢不同亚型M受体有关。上述三药均引起心率减慢。     

The effect of surgically induced anterior disc displacement of the temporomandibular joint on the midface and cranial base

This investigation studies the development of mandibular and cranial base asymmetries with the aid of an animal model. The effect internal derangement of the temporomandibular joint (TMJ) might have on the asymmetric development of the cranial base is not known. The purpose of this study was to investigate the consequences of unilateral TMJ disc displacement on the midface and cranial base. Thirteen 10-week-old rabbits, eight controls and five experimental were included in this study. The five experimental rabbits had surgically created unilateral disc displacement. Animals were sacrificed at 22 weeks and frontal, occlusal and lateral oblique radiographs were made of the skulls. The occlusal radiograph demonstrated that the glenoid fossa on the experimental side was located more anteriorly. Whereas, the oblique radiograph revealed the root of the zygomatic arch on the experimental side to be more inferior. Finally, the anterior aspect of the fossa was seen to be more inferior on the frontal radiograph. A previous study suggested a shortening in the ramal height. This study points to an alteration of the cranial articular fossa. Thus, it may be concluded that disc displacement is capable of producing asymmetry in both the developing mandible and the cranial base.     

DNEPs在缺血性脊髓损伤手术中的变化及其意义

目的观察兔子不同程度缺血性脊髓损伤后经棘突电刺激下传神经源性运动诱发电位(DNEPs)的变化特点,为在脊柱脊髓手术中持续监测脊髓功能提供理论依据。方法通过不同程度的永久性脊髓缺血动物模型,研究经棘突间接电刺激运动诱发电位在缺血早期的变化特点,并分析波形变化与运动功能的相关性。结果经棘突电刺激间接脊髓运动诱发电位对缺血性损伤敏感,血管结扎后30min的波幅与运动功能呈显著性正相关,Pearson相关系数r=0.976,早期波幅变化可以评估预后,波幅与基线的比值与病理损害程度相关。结论经棘突电刺激间接脊髓运动诱发电位可以用于脊柱脊髓手术中连续监测脊髓功能,其对缺血敏感,与运动功能相关,术中应用可以预防术后术后神经功能障碍。     

兔急性弥漫性颅高压模型TCD参数与颅内压和脑灌注压的相关性研究

目的采用兔急性弥漫性颅高压模型，研究经颅多普勒（TCD）参数与颅内压（ICP）和脑灌注压（CPP）的相关性。方法新西兰兔20只，随机分组：A组（对照组）8只，枕大池穿刺后不注入林格氏液；B组（实验组）12只，枕大池穿刺后逐步持续注入林格氏液。穿刺前、穿刺后每隔15 min监测ICP、HR、MAP、R及TCD各参数，并计算出CPP。结果A组各参数穿刺前后各时点比较无统计学差异。随着ICP的升高，B组TCD各参数与ICP、CPP有密切线性关系；TCD的变化发生在生命体征改变之前，更早于Cushing反应；在濒死前期，TCD出现一“反跳”现象，出现“反跳”的兔83.3%死亡。结论TCD的变化能较早地反映ICP和CPP的变化，同时ICP增高晚期出现的特征性“反跳”现象提示预后极差。     

曲克芦丁对家兔血脂及动脉粥样斑块形成的影响

60只家兔经动脉粥样硬化造型后,30只用曲克芦丁100mg(2mL),im,qd×4wk,另外30只家兔用生理盐水2mL,im,qd×4wk作比较,发现曲克芦丁明显降低家兔血浆总胆固醇及载脂蛋白B,明显升高高密度脂蛋白胆固醇的作用,(P<0.01),且对动脉粥样硬化斑块形成具有抑制或消除作用,而生理盐水组则无上述作用。     

结扎家兔颈总动脉后海马的组织学变化

家兔颈总动脉单侧结扎、双侧不同时结扎和双侧同时结扎后,海马组织学的主要变化是海马中间部多型细胞层的小血管淤血,引起海马边缘部的锥体细胞层周围毛细血管贫血,锥体细胞供血不良,使其轴突萎缩。海马CA_3区突触小体内的线粒体嵴及颗粒消失,突触小泡减少、内移及致密化,这种变化随结扎程度的不同逐渐加深,尤以双侧同时结扎最为明显。为颈总动脉结扎后影响学习记忆提供了组织学依据。     

香烟烟雾对家兔的毒害作用

通过对家兔被动吸烟及静脉注射香烟烟雾溶液的毒害作用试验,推算出主动吸烟的人香烟中毒量;并通过对其病理解剖及组织观察,见到香烟烟雾能引起如下变化:使细胞的脂质膜溶掉,切断体内细胞的生物氧化链,血红蛋白变性,心肌疏离,心肌内血管收缩,以及使肺、肝等器官产生较多的癌变前期的细胞。     

Provoked Repetitive Healing of Mature Bone Tissue Following Irradiation a Quantitative Investigation

A titanium implant, the bone harvest chamber (BHC), was used to investigate the regenerative capacity of mature bone after irradiation. One BHC was inserted in each proximal tibial metaphysis of a rabbit. One of these implant sites was irradiated (⁶⁰Co single dose) to either 15 or 25 Gy while the other served as control. Newly formed bone grew through a canal that penetrated the implant. This newly formed bone was harvested from the implant every three weeks following irradiation and then quantified by microradiography and computer-assisted densitometry. In this way a ratio between bone formed on the irradiated side in comparison with the control could be established. An immediate depression in bone formation compared with the non-irradiated controls, was seen at both dose levels. A recovery in bone regenerative capacity was seen at 15 weeks after 15 Gy while the decrease in bone formation remained constant after 25 Gy during the 30 week follow-up period.     

手法治疗对兔膝关节软骨缺损的修复效果

目的：评价手法治疗对兔膝关节软骨浅层和深层缺损修复的效果。 方法：将24只新西兰兔随机分成手法组和对照组。分别在24只兔双侧膝关节的股骨内侧髁造成直径2mm的浅层软骨缺损,在股骨髌面造成直径3mm的深层软骨缺损。造模4周后,手法组采取手法治疗,对照组不采取任何治疗措施。分别于治疗后4、8、12周取材,对缺损区域的修复组织进行外观形态、苏木精和伊红（hematoxylin and eosin,HE）染色、番红O染色以及Ⅱ型胶原免疫组织化学染色观察,并采用O’Driscoll软骨组织形态学评分评价软骨缺损的修复质量。 结果：治疗后,手法组软骨浅层缺损和软骨深层缺损渐渐修复。修复组织质地稍软,表面光滑,外观与正常软骨类似,大部分区域与周围正常软骨界限模糊,与周围软骨整合良好。对照组浅层缺损虽然有部分被修复,但所修复组织与周围软骨界限清晰;深层缺损只是缺损面积略减小．未见到缺损修复,或以纤维样组织填充。HE染色显示手法组修复组织内有大量的透明软骨细胞,番红O染色显示手法组修复组织基质染色接近周围正常关节软骨,对照组无染色。Ⅱ型胶原免疫组织化学染色显示,手法组浅层缺损和深层缺损的修复组织Ⅱ型胶原染色与正常软骨相比染色正常甚至较深;对照组浅层和深层缺损的修复组织无染色,修复组织与正常组织界限清晰。O’Driscoll评分结果显示,手法组的浅层缺损和深层缺损的评分均高于同一时间段对照组,差异有统计学意义（P〈0．01）;治疗后,手法组无论浅层缺损还是深层缺损,各时间点O’Driscoll评分比较,差异均无统计学意义（P〉0．05）。 结论：手法治疗能有效地修复兔膝关节的浅层软骨缺损和深层软骨缺损,修复物质与透明软骨相似。