鞘内注射吗啡加可乐定对切口痛大鼠脊髓背角蛋白激酶A催化亚单位表达的影响

Objective To observe the effect of intrathecal clonidine plus morphine on expression of protein kinase A (PKA) catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods Eighty male Sprague-Dawley rats were divided randomly into five groups: sham group, control group, pre-incisional morphine 2.5 μg group, pro-incisional clonidine 5 μg group and preincisional morphine 2.5 μg plus clonidine 5 lag group (n=16). lntrathecal catheter and the model of incisional pain were pro-duced according to Yaksh and Brennan's described method respectively. Changes of pain behavior were assessed by mechanical with-drawal threshold (MWT) and thermal withdrawal latency(TWL). The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistochemical method and western blotting analysis. Results Compared with sham group, MWT and TWL in control group were decreased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group (P<0.01). Compared with control group, MWT and TWL in pre-incision morphine 2 μg plus clonidine 5 lag group were increased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre-incision morphine 2 μg plus clonidine 5 μg group (P<0.01). However, MWT, TWL and the number of positive cells and pro-tein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre-incisional morphine 2.5 μg group and pre-incisional clonidine 5 μg group compared with control group. Conclusion lntrathecal clonidine significantly enhances the antinociceptive effect of intrathecal morphine in a rat model of incisional pain, which might be associated with inhibi-tion of the increased expression of PKA catalytic subunit in spinal cord.     

脊柱后路减压治疗胸腰段骨折脱位合并脊髓损伤术式选择

目的研究两种不同脊柱后路减压方法治疗胸腰段骨折脱位合并脊髓损伤的手术治疗效果。方法回顾分析本院1996年3月～2002年6月收治的胸腰段骨折脱位并脊髓损伤患者76例，按不同减压方法将其分为两组：切除一侧或两侧椎板、椎弓根或部分关节突行侧前方环状减压AF内固定者40例，为直接减压组；体位复位结合AF器械矫正复位36例，为间接减压组。统计学分析，两组资料具有可比性。对术后神经功能恢复情况，按ASIA神经功能评定标准进行评定。中晚期并发症，根据是否有腰背痛，下肢根性痛、麻木无力，两便功能障碍进行评定。生活能力按FIM评定。结果两组病例获6个月～5年随访，结果表明，术前脊髓完全性损伤，术后均无恢复；术前脊髓不完全性损伤，术后两组间比较差异无显著性。中晚期并发症发生，直接减压组高于间接减压组；术后生活自理能力，间接减压组好于直接减压组。结论间接减压手术方法治疗胸腰段骨折脱位合并脊髓损伤不失为一种早期治疗的首选方法。     

Characterization of hindlimb motoneuron membrane properties in acute and chronic spinal cats

The purpose of this study was to determine if changes in hindlimb motoneuron membrane electrical properties occur 4–6 months after spinal transection in the adult animal. Eight acute and nine chronic animals were spinalized at T₁₂. Intracellular recordings from motoneurons innervating the triceps surae were performed. Membrane electrical properties, including resting potential, action potential peak amplitude, afterhyperpolarization duration, rheobasic current, input resistance and axonal conduction velocity were measured. There were no statistical differences found between group means or frequency distributions in the membrane properties of motoneurons assessed from acute and chronic spinal animals. Thus, alteration of motoneuron membrane properties does not appear to be a major contributing factor to the hyperexcitable hindlimb reflex activity demonstrated by chronic spinal animals.     

Metabolism and binding of androgens in the spinal cord of the rat

The binding of [3H]androgens and estrogens, and the metabolism of [3H]androgens, were studied in the spinal cord of the adult rat. High-affinity, specific binding sites for [3H]testosterone and [3H]estradiol were detected in cytosol fractions from the spinal cords of castrate animals. Equilibrium dissociation constants for reaction of these sites with their respective ligands were similar to those of androgen and estrogen receptors from other regions of the central nervous system. Nuclear binding of [3H]estradiol was observed in the spinal cord 1 h after intravenous administration of the isotope. Likewise, exchange assay demonstrated the presence of high-affinity androgen binding sites in spinal cord nuclei from orchidectomized, testosterone propionate treated animals. 5 alpha-Reductase activity in homogenates of the spinal cord was relatively high, approximately 3 times that in the pooled hypothalamus, preoptic area, septum and amygdala. However, in contrast to the latter brain regions, estrogen formation was not detectable in spinal cord tissue. No sex differences were observed in the metabolism of [3H]testosterone by spinal cord homogenates. These results confirm the presence of androgen and estrogen receptors in the rat spinal cord. The lack of detectable aromatase activity in the spinal cord is consistent with the hypothesis that the effects of circulating testosterone on spinal reflex function are mediated primarily through the androgen receptor system.     

Association between cord blood IgE and genetic polymorphisms of interleukin-4, the β-subunit of the high-affinity receptor for IgE, lymphotoxin-α, and tumor Necrosis factor-α

High cord blood immunoglobulin E (cbIgE) is known to be associated with increased risks of atopic diseases in childhood. The relationship between genetic polymorphisms and high cbIgE has not been well documented. A cross-sectional study was conducted to assess the association between cbIgE and genetic polymorphisms of interleukin (IL)-4 -590C/T, the beta-subunit of the high-affinity receptor for IgE (FcepsilonRI-beta) E237G, lymphotoxin (LT)-alphaNcoI alleles, and tumor necrosis factor (TNF)-alpha -308G/A. A total of 320 mother-neonate pairs were recruited from four maternity hospitals from different locations of Taiwan. Cord blood was obtained and assayed for cbIgE. Polymerase chain reaction followed by restriction fragment length polymorphism was used to assess the genotypes. Three hundred pairs of mothers and neonates were included in the final analysis. Infants with IL-4 -590 C allele were found to have higher risk of elevated cbIgE (> or =0.35 IU/ml, 24.3%) (p = 0.004). After adjusting for gender, birth order, maternal age, and history of allergic disease in maternal and paternal families, odds ratios for CC and CT genotypes were 4.41 and 3.16 (95% confidence interval 0.78-22.67, and 1.66-6.13), respectively, using TT genotype as reference. The genotypes of FcepsilonRI-beta, LT-alpha, and TNF-alpha were not associated with cbIgE before or after the adjustment. Our finding suggested a significant association of cbIgE with genetic polymorphism of IL-4 -590C/T, but not with the genotypes of FcepsilonRI-beta, LT-alpha, and TNF-alpha.     

Fusimotor reflexes to antagonistic muscles simultaneously assessed by multi-afferent recordings from muscle spindle afferents

Several single agonist/antagonist primary muscle spindle afferents were simultaneously recorded in chloralose anaesthetized cats. It was shown that their dynamic and static sensitivity to sinusoidal muscle stretches could be increased or decreased via the fusimotor system by extension and flexion of the contralateral hind limb as well as by stretch of ipsilateral muscles and stimulation of ipsilateral skin nerves. The results seem to support the hypothesis that the primary muscle spindle afferents convey complex multisensory messages to the central nervous system (CNS).     

Elemental composition and water content of myelinated axons and glial cells in rat central nervous system

The distribution of elements (e.g. Na, Cl, K) and water in CNS cells is unknown. Therefore, electron probe X-ray microanalysis (EPMA) was used to measure water content and concentrations (mmol/kg dry or wet weight) of Na, Mg, P, S, Cl, K and Ca in morphological compartments of myelinated axons and glial cells from rat optic nerve and cervical spinal cord white matter. Axons in both CNS regions exhibited similar water content ( 90%), and relatively high concentrations (wet and dry weight) of K with low Na and Ca levels. The K content of axons was related to diameter, i.e. small axons in spinal cord and optic nerve had significantly less (25–50%) K than larger diameter axons from the same CNS region. The elemental composition of spinal cord mitochondria was similar to corresponding axoplasm, whereas the water content (75%) of these organelles was substantially lower than that of axoplasm. In glial cell cytoplasm of both CNS areas, P and K (wet and dry weight) were the most abundant elements and water content was approximately 75%. CNS myelin had predominantly high P levels and the lowest water content (33–55%) of any compartment measured. The results of this study demonstrate that each morphological compartment of CNS axons and glia exhibits a characteristic elemental composition and water content which might be related to the structure and function of that neuronal region.     

Nociceptin (Orphanin FQ) abolishes gestational and ovarian sex steroid-induced antinociception and induces hyperalgesia

Nociceptin (Orphanin FQ) is a newly discovered endogenous heptadecapeptide substrate for the opioid-receptor-like 1 receptor, a G protein coupled receptor that bears striking amino acid sequence homology to opiate receptors. In rats, intrathecal (i.t.) administration of nociceptin is without effect on basal thresholds for responsiveness to electric foot shock. However, during either late gestation or its hormonal simulation, when nociceptive thresholds are elevated by approximately 70%, i.t. nociceptin substantially attenuates jump thresholds in a dose-dependent fashion. This hypoalgesic effect of nociceptin is not limited to attenuating the gestational or sex steroid-induced increment in pain thresholds. Following the highest i.t. dose of nociceptin employed (20 nmol), the gestational or sex steroid-induced increment in jump thresholds is not only abolished but a significant hyperalgesia is observed. These results underscore the importance of the hormonal milieu to nociceptin hypoalgesic sensitivity. The potential contribution of spinal nociceptive pathways that utilize nociceptin to the etiology of extraordinary painful pregnancy and labor should not be ignored.     

脐血LAK细胞生物学特性影响因素的研究

采集２３名产妇的脐带血和８名正常成人的外周血制备ＬＡＫ细胞，随机分为４组，在培养第３，５，７，１４天，分别利用ＭＴＴ法和＾１２５Ｉ－ＵｄＲ释放法对４组ＬＡＫ细胞的增殖力和杀伤活性进行了测定，同时用细胞毒方法测定培养７天的ＬＡＫ细胞的免疫表型。结果发现，在不同培养时间，脐血来源的ＬＡＫ细胞增殖力显著高于成人血ＬＡＫ细胞（Ｐ〈０．０５或Ｐ〈０．０１），成人血清组，脐血血清组，红细胞组ＬＡＫ细胞增殖力有