核因子kB在大鼠胃缺血再灌注损伤中的表达及意义

目的研究核因子kB（NF-kB）在大鼠胃缺血再灌注损伤中的表达及意义。方法采用大鼠胃缺血再灌注（gustric ischemia/reperfusion, CI／R）模型（夹闭腹腔动脉30min后再灌注），分别于再灌注0．5、1、3、24h取胃，计算胃黏膜损伤指数。应用免疫组化、Western blot方法检测胃黏膜NF-kB p65。结果大鼠GUR后引起胃黏膜损伤，再灌注1h时损伤最明显，随后降低，24h接近正常。GI／R后胃黏膜NF—kB阳性细胞数和蛋白表达量增多，与胃黏膜损伤变化规律一致。结论NF-kB在大鼠CI／R损伤过程中发挥着重要作用。     

腹膜透析对重症急性胰腺炎大鼠肾损害的保护作用

目的探讨腹膜透析(PD)对重症急性胰腺炎(SAP)大鼠肾损害的保护作用并探讨可能的机制。方法SD大鼠72只随机分为对照组(24只)、SAP组(24只)和PD组(24只),观察各组血清前列腺素(TXA2/6-K-PGF1a)及内皮素(ET-1)水平和肾脏病理变化。结果SAP组和PD组血清ET-1水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低;SAP组和PD组血清TXA2/6-K-PGF1a水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低。PD组大鼠肾病理损害较SAP组明显减轻。结论血液流变异常参与SAP肾损害的发生,早期进行PD治疗对SAP大鼠肾有保护作用,其可能的机制是改善微循环、清除炎症介质等。     

骨髓基质干细胞移植对大鼠胶质瘤局部微环境的影响

目的:探讨骨髓基质干细胞(BMSCs)移植对脑胶质瘤模型大鼠(荷瘤大鼠)胶质瘤的影响。方法:观察BMSCs培养上清液对C6胶质瘤细胞增殖活性、细胞周期的影响。观察脑内移植BMSCs对胶质瘤核增殖抗原(PCNA)表达阳性率、脑内胶质瘤微血管计数的影响及荷瘤鼠生存期的改变。结果:BMSCs培养上清液对胶质瘤细胞增殖没有明显的影响;BMSCs可抑制肿瘤边缘及卫星灶的肿瘤增殖,对肿瘤内部的细胞增殖没有明显影响。移植BMSCs后肿瘤边缘及卫星灶的微血管计数未见明显改变。移植BMSCs后的荷瘤大鼠脑内胶质瘤水肿有所减轻。结论:BMSCs移植可轻度抑制荷瘤鼠脑内胶质瘤细胞的增殖。     

Neurosteroid modulation of allopregnanolone and GABA effect on the GABA-A receptor

The neurosteroid allopregnanolone (ALLO) or 3α-OH-5α-pregnane-20-one interacts with the GABA type A receptor chloride ion channel complex and enhances the effect of GABA. Animal and human studies suggest that ALLO plays an important role in several disorders including premenstrual syndrome, anxiety, and memory impairment. In contrast to ALLO, steroids with a hydroxy group in the 3β position usually exert a reducing effect and have recently attracted interest due to their suggested role in counteracting the negative action of ALLO. In this study, five different 3β-steroids were tested for their ability to modulate GABA-mediated chloride ion uptake in the absence and presence of ALLO in rat brain microsacs preparations. In addition, the effects of the 3β-steroids and their interaction with ALLO were investigated by patch-clamp recordings of spontaneous inhibitory postsynaptic currents (sIPSCs) in rat hypothalamic neurons from the medial preoptic nucleus (MPN). All tested 3β-steroids reduced the ALLO-enhanced GABA response in cerebral cortex, in hippocampus and in MPN. In cerebellum, only one had this effect. However, in the absence of ALLO, two of the 3β-steroids potentiated GABA-evoked chloride ion uptake and prolonged the sIPSCs decay time, whereas the others had little or no effect. Therefore, it is possible that at least some 3β-steroids can act as positive GABA_A receptor modulators as well as negative modulators depending on whether or not ALLO is present. Finally, these results suggest that the 3β-steroids could be of interest as pharmacological agents that could counteract the negative effects of ALLO.     

DSP-4, a noradrenergic neurotoxin, produces more severe biochemical and functional deficits in aged than young rats

The present study examines the effects of noradrenergic lesions (either DSP-4 i.p. or 6-hydroxydopamine (6-OHDA) into the dorsal noradrenergic bundle on biochemical (noradrenaline (NA), dopamine (DA), serotonin (5-HT) and choline acetyltransferase (ChAT) activity) and cortical EEG (quantitative EEG (qEEG) and high-voltage spindle (HVS) activity in young and aged rats. Near complete 6-OHDA NA lesions, but not partial DSP-4 NA lesions, increased HVS activity in young rats. DSP-4 and 6-OHDA lesions produced no significant changes in the 5-HT or DA levels or in the ChAT activity in young rats. In some of the aged rats, DSP-4 produced similar biochemical and HVS effects, as it induced in young rats. In the remainder of the aged rats, NA levels were greatly and 5-HT levels slightly decreased. DA levels and ChAT activity were unaltered in either set of aged rats. HVS activity was increased only in that group of aged rats with the greatly lowered NA content. These results suggest that: (1) some of the aged rats are more sensitive to DSP-4 treatment than young adult rats; and (2) NA depletions have to be complete to produce an increase in HVS activity in young and aged rats.     

Radioiodinated tracers for the evaluation of dopamine receptors in the neonatal rat brain after hypoxic-ischemic injury

In order to evaluate in vivo single-photon emission tomography (SPET) method of assessing cerebral function after hypoxic-ischemic injury in human neonates, we studied D₁ and D₂ dopamine receptors in a rat model. Seven-day-old rats underwent permanent unilateral common carotid ligation followed by exposure to 8% O₂. Two weeks later, in brains with no visible loss of hemispheric volume, striatal dopaminergic receptors were studied, with [¹²⁵I]TISCH and [1251]IBZM for the D₁ and D₂ dopamine receptors, respectively. Using [¹²⁵I]TISCH, we observed no modifications of D₁ receptors, but in contrast, ex vivo and in vitro autoradiographic experiments showed a 40% decrease in the striatal binding of [¹²⁵I]IBZM on both the ipsilateral and the contralateral side to the carotid ligation. These alterations were detected with IBZM, a D₂ dopamine receptor ligand usable for SPET imaging. Therefore, exploration of D₂ receptors by SPET in human neonates suffering from perinatal hypoxia-ischemia may be valuable for the diagnosis and follow-up of cerebral function damages. Correspondence to: D. Guilloteau     

REPAIR AND RECOVERY FOLLOWING SPINAL CORD INJURY IN A NEONATAL MARSUPIAL (MONODELPHIS DOMESTICA)

1. Repair and recovery following spinal cord injury (complete spinal cord crush) has been studied in vitro in neonatal opossum (Monodelphis domestica), fetal rat and in vivo in neonatal opossum. 2. Crush injury of the cultured spinal cord of isolated entire central nervous system (CNS) of neonatal opossum (P4–10) or fetal rats (E15–E16) was followed by profuse growth of fibres and recovery of conduction of impulses through the crush. Previous studies of injured immature mammalian spinal cord have described fibre growth occurring only around the lesion, unless implanted with fetal CNS. 3. The period during which successful growth occurred in response to a crush is developmentally regulated. No such growth was obtained after P12 in spinal cords crushed in vitro at the level of C7–8. 4. In vivo, in the neonatal (P4–8) marsupial opossum, growth of fibres through, and restoration of, impulse conduction across the crush was apparent 1–2 weeks after injury. With longer periods of time after crushing a considerable degree of normal locomotor function developed. 5. By the time the operated animals reached adulthood, the morphological structure of the spinal cord, both in the region of the crush and on either side of the site of the lesion, appeared grossly normal. 6. The results are discussed in relation to the eventual longterm possibility of devising effective treatments for patients with spinal cord injuries.     

硬化性腹膜炎的动物实验研究

本文用大鼠建立持续腹膜透析（ＣＡＰＤ）实验模型，模拟ＣＡＰＤ中长期接触生物不相容物质所致的腹膜硬化关系。结果表明，乳酸盐透析液有较好的生物相容性，醋酸盐透析没有肯定的致腹膜硬化作用。单纯高糖高渗透析液也有致腹膜硬化的作用。若伴有细菌感染以及消毒液（如碘液）污染透析液，则可加重腹膜损伤和硬化程度，并对临床上防治硬化性腹膜炎的措施进行了探讨。