生物人工周围神经修复大鼠不同长度周围神经缺损

目的 采用一种自行研制的具有良好生物相容性的部分脱乙酰甲壳质构建人工神经来修复大鼠坐骨神经不同长度的缺损，研究证实其修复效果。方法 选用24只健康雄性SD大鼠，随机分为3组造成不同长度（5、10、15mm）的坐骨神经缺损，右侧进行人工神经桥接修复，左侧进行原位神经移植。12周后进行神经电生理检测以及组织学检测。结果 5mm以及10mm组，光镜下能够观察到人工神经内新生的纤维延续存在。组织学证明。此种人工神经能够有效的修复10mm以内的大鼠坐骨神经缺损；神经肌肉复合动作电位的产生表明：12周后神经已经长过缺损段，神经传导功能恢复，并且已经长入远端靶器官。结论 结果证明这种套管能够有效的桥接10mm的大鼠坐骨神经缺损（神经直径的6～8倍）。可能应用于周围神经缺损的治疗。同时可以作为进一步开发组织工程化的人工神经的良好载体。     

芪胆通痹汤治疗类风湿性关节炎作用机理的实验研究

目的　研究芪胆通痹汤对大鼠Ⅱ型胶原类风湿性关节炎 (RA)模型的作用机理 ,观察“清少阳、益肝肾”治法的疗效。方法　免疫学实验方法。结果　该方能有效减轻大鼠局部足肿胀程度及降低炎症组织中前列腺素 (PGE2 )含量 (P <0 0 1) ,并且具有镇痛作用 ;能显著抑制DNFB所致的小鼠DTH反应 (P <0 0 1)、抑制DTH小鼠脾脏T细胞增殖 (P <0 0 1) ,血清在 1∶2比例稀释下能显著抑制脾细胞IL 2的分泌 (P <0 0 1)。结论　芪胆通痹汤能有效缓解RA症状 ,并通过抑制Ⅳ型免疫变态反应治疗RA。     

经鼻蝶窦手术动物模型神经内镜手术训练

目的建立一种活体动物的神经内镜经鼻蝶手术模拟训练方法。方法选择大鼠，建立一套训练计划，完成内镜图像导引下的内镜操作，电凝止血、冲洗和吸引、活检等神经内镜经鼻蝶手术的基本技巧。结果利用大鼠颅脑进行模仿内镜经鼻蝶手术，如在内镜图像导引下操作内镜的方法；熟悉内镜系统、电凝系统、冲洗和吸引设备的使用；熟悉了神经内镜经鼻蝶手术的步骤。结论作为神经内镜实验室训练的重要组成部分，通过利用大鼠颅脑进行模拟神经内镜手术，训练者可以从中获得神经内镜操作基本技巧的练习。     

Prejunctional effects of muscarinic agonists on 3H-acetylcholine release in the rat urinary bladder strip

Summary The inhibitory effects of some muscarinic agonists on tritiated acetylcholine release evoked by field stimulation were investigated in the rat urinary bladder strip. The acetylcholine stores of the preparation were labelled with ³H-choline. Electrical field stimulation caused an outflow of tritium, reflecting the release of ³H-acetylcholine. The release of ³H-acetylcholine was decreased in a concentration-dependent manner by all the agonists tested: oxotremorine, muscarone, muscarine, carbachol and methylfurtrethonium. On the contrary, only muscarine and muscarone enhanced the basal efflux of tritium in a concentration-dependent fashion. Concentration-response curves were determined both at 2 Hz and at 1 Hz by using intermittent administration of the drugs. Maximal depression in release (by 78 – 82%) was observed in experiments at 1 Hz. A similar inhibition was obtained at 2 Hz frequency only when a low concentration of calcium (0.6 mM) in the medium was used. Oxotremorine was the most potent among the tested compounds with the same intrinsic activity as the other drugs. In contrast to the other agonists investigated, oxotremorine showed in about 10-fold greater potency at pre- than at postjunctional muscarine receptors in the rat urinary bladder. This difference might depend either on heterogeneity of muscarine receptors or on different mechanism(s) relating to the transducing properties of receptors at the pre- and postjunctional level. A comparison between the relative prejunctional potencies in the rat urinary bladder and in the guinea pig myenteric plexus (data from the literature) suggests that prejunctional muscarine receptors are similar in these tissues. Furthermore, the findings obtained with a low concentration of calcium in the medium may support the view that intraneuronal availability of calcium plays a significant role in modulating the prejunctional negative feed-back mechanism in the rat urinary bladder.Send offprint requests to Dr. G. D'Agostino at the above address     

Inhibition of Calcium Oxalate Monohydrate (COM) crystal growth by pyrophosphate,citrate and rat urine

Summary An assay system for the measurement of the rate of Calcium Oxalate Monohydrate (COM) seed crystal growth in a metastable solution of calcium chloride and sodium oxalate containing traces of ¹⁴C-oxalic acid was used to assess the inhibitory activity of pyrophosphate (10^–5 M-10^–4 M), citrate (10^–4 M-10^–3 M) and urines of normal and pyridoxine deficient rats. Both pyrophosphate and citrate were strong inhibitors of COM crystal growth and caused a 50% decrease in crystal growth rate at 1.50×10^–5 M and 2.85×10^–4 M respectively. Normal rat urine strongly inhibited the COM crystal growth, while pyridoxine deficient animals showed a significant (p< 0.01) decrease in mean inhibitory activity as compared to pair-fed controls. A lowered urinary inhibitory potential accompanied with hyperoxaluria and hypercalciuria, which is known to be associated with pyridoxine deficiency, may be a contributory risk of calcium oxalate crystallization and stone formation.     

中性粒细胞在高浓度氧诱发急性肺损伤中的作用

目的:测定鼠支气管肺泡清洗液中细胞成分,阐明高浓度氧诱发急性肺损伤的发生机制。方法:20只雄性6周龄[(226±53.6)g]Wistar鼠被分为3组:(1)对照组(空气中饲养,n=6)。(2)实验组1(暴露在90%～95%氧气中24～48h,n=7)。(3)实验组2(暴露在90%～95%氧气中72h,n=7)。实验中动物可自由进食和水。结果:与对照组相比,实验组2的支气管肺泡清洗液中总细胞数减少[(3.81±0.35)×105/ml,(2.53±0.77)×105/ml];巨噬细胞数减少[(3.80±0.36)×105/ml,(2.09±0.59)×105/ml];而中性粒细胞计数明显增多[0,(43.56±42.63)×103/ml]。实验组2的动物都出现双侧胸水。结论:中性粒细胞动员并进入肺组织是高浓度氧诱发急性肺损伤的明显特征,损伤的发生与暴露时间有关。提示早期抑制中性粒细胞进入肺组织是治疗高浓度氧诱发急性肺损伤的重要途径。     

Ependymal lining of infundibular recess in perinatal rats: Relationships with portal capillaries and permeability

Structure and permeability of the ependymal lining the infundibular recess were studied in perinatal rats with silver impregnation, electron microscopy, radioautography, and tracer techniques. According to our data basal processes of ependymal cells reach the primary portal plexus linking the 3rd ventricle and the hypophysial portal system all through the perinatal period. After birth, some of the processes penetrate into the perivascular space of the primary portal plexus and abut there on the endothelium of capillaries. Ependymal cells of fetuses and neonates are joined by specialized junctions (tight junctions, gap junctions and zonulae adhaerentes). Intraventricularly injected ionic lanthanum crosses the ependymal lining of fetuses both trans- and extra-cellularly everywhere in the infundibular recess. By postnatal day 9 only the rostral portion of the recess remains readily permeable. Caudally, extracellular leakage becomes highly restricted, apparently due to the appearance of circumferential tight junctions. Finally, [3H]dopamine seems to penetrate through the ependymal lining in the same way as ionic lanthanum entering the portal capillaries. These findings suggest that the adenohypophysiotropic neurohormones can penetrate from the cerebrospinal fluid into the portal circulation from the very beginning of the establishment of the hypothalamo-hypophysial functional relationships during ontogenesis.     

Stimulation-induced setting of postural muscle tone in the decerebrate rat

These studies demonstrate the presence of pontomedullary areas in the rat brainstem which, when stimulated electrically, serve to set postural muscle tone in the hindlimbs. Low amplitude stimulation of the dorsal tegmental field (DTF) was found to inhibit postural muscle tone and, in some rats, was found to decrease mean arterial pressure. Low amplitude stimulation of the ventral tegmental field (VTF) was found to increase postural muscle tone and, in all cases tested, was found to increase mean arterial pressure.     

Amphetamine impairs the discriminative performance of rats with dorsal noradrenergic bundle lesions on a 5-choice serial reaction time task: New evidence for central dopaminergic-noradrenergic interactions

A series of experiments examined the effects of lesions of the dorsal noradrenergic bundle (DNAB), induced by 6-hydroxydopamine (6-OHDA), on the behavioural response to systemic and intra-accumbens amphetamine, using a rat analogue of Leonard's 5-choice serial reaction time task for humans. Although the 6-OHDA DNAB lesion produced a profound depletion of cortical noradrenaline (NA) (to around 5% of control levels) it did not impair any aspect of performance on this task. Both systemic and intra-accumbens amphetamine increased behavioural measures of impulsivity of responding, but neither impaired discriminative accuracy in the sham-operated control rats. However, the DNAB lesioned rats did show a discriminative impairment following both low doses of systemic amphetamine, and intra-accumbens amphetamine. The latter effect was antagonised by systemic administration of the specific dopaminergic (DA) antagonist alpha-flupenthixol. The DNAB lesion did not alter the effect of amphetamine on any other behavioural measure, including speed and impulsivity of responding. These results suggest that although DA and NA participate in qualitatively different behavioural processes, the effects of DNAB lesions on attentional processes depend on the level of DA activity within the nucleus accumbens.