牛磺酸锌对睡眠剥夺大鼠脑认知功能的影响及机理

目的:探索补锌对睡眠剥夺(SD)后大鼠脑认知功能的影响及机制。方法:采用小平台水环境法制作大鼠SD模型,3天后通过Y-型迷宫行为测试结合NADPH-d组化与免疫组化ABC法,分别观察大鼠海马结构不同亚区内一氧化氮合酶(NOS)活性与神经元型一氧化氮合酶(nNOS)蛋白表达水平的变化。结果:SD组大鼠迷宫实验学会次数(89.3±25.3)较正常对照组大鼠(67.1±29.3)增加(t=1.81,P<0.05),补牛磺酸锌(5.9g/kg饲料牛磺酸锌水平)组大鼠的迷宫实验学会次数(71.9±21.4)较SD组减少(t=1.66,P<0.05)。与正常对照组大鼠海马结构的NOS(CA1:32.6±2.1;CA3:20.5±1.8;DG:27.5±1.8)活性和nNOS蛋白(CA1:68.3±4.1;CA3:41.7±2.5;DG:44.4±2.8)表达相比,SD组大鼠海马结构各亚区NOS(CA1:14.8±1.2;CA3:10.6±1.0;DG:13.1±1.3)活性和CA1区与齿状回nNOS蛋白(CA1:51.3±3.6;DG:41.6±2.7)表达减少(P<0.05),CA3区nNOS蛋白变化不明显(38.1±4.8,P>0.05)。与SD组大鼠相比,补牛磺酸锌组大鼠海马结构不同亚区内的NOS表达增加(CA1:27.2±2.8;CA3:15.3±1.6;DG:21.8±1.9,P<0.05),CA1区的nNOS蛋白表达增加(60.1±3.4,P<0.05),CA3和齿状回nNOS表达变化不明显(CA3:39.6±4.9;DG:42.8±3.5,P>0.05)。结论:牛磺酸锌对大鼠学习记忆功能有促进作用,其机理可能与上调海马结构NOS、nNOS表达水平有关。     

cDNA cloning of two A-superfamily conotoxins from Conus striatus.

The full-length cDNAs of two A-superfamily conotoxins, kappaA-SIVA and alpha-SII, were respectively cloned and sequenced from Conus striatus using 3' RACE and 5' RACE. The cDNA of kappaA-SIVA encodes a precursor of 68 residues, including a signal peptide of 21 residues, a pro-peptide of 17 residues, and a mature peptide of 30 residues with an additional residue Gly which is prerequisite for the amidation of the preceding C-terminal Cys. The cDNA-deduced sequence of alpha-SII is composed of a signal peptide of 21 residues, a pro-peptide of 29 residues, a mature peptide of 19 residues and three additional residues Arg-Thr-Ile at the C-terminus. This tripeptide might be cleaved off by proteolytic processing. Although these two conotoxins belong to different families and target voltage-gated potassium channel and nicotinic acetylcholine receptor, respectively, they share the same signal sequence, and both are processed at the common signal site -X-Arg- immediately before the mature peptide sequences. The length of 3' untranslational region of alpha-conotoxin SII was extraordinarily large about 10 times longer than that of kappaA-SIVA with 770 and 75 bp, respectively. The elucidated cDNAs of these two toxins will facilitate a better understanding of the process of their post-translational modifications.     

山东省18岁及以上人群精神障碍流行病学调查

目的:了解山东省≥18岁人群精神障碍的患病率及分布特点。方法:采用多阶段分层整群抽样方法,随机抽取山东省5个地级市的5个区和15个县的10个街道和30个乡镇,共计20个居委会和60个行政村,抽取≥18岁人群23987人,由精神科护士用扩展的一般健康问卷(GHQ-12)进行筛查,将调查对象分为精神障碍高、中、低危险组,然后由精神科医生用美国精神障碍诊断与统计手册(DSM-IV)轴Ⅰ障碍定式临床检查患者版对不同比例的高、中和低危人群进行调查,作出有无精神障碍及具体诊断。结果:完成调查22718人,调整后精神障碍总的现患率(最近1个月)为19.48%(95%CI:17.48%～21.64%)。各类精神障碍现患率由高到低依次为心境障碍(5.93%)、物质使用障碍(5.62%)、焦虑障碍(5.50%)、精神病性障碍(1.28%)。男性精神障碍总的现患率(22.78%)高于女性(16.17%)(OR=1.53)。城市居民精神障碍的现患率(18.88%)与农村(19.68%)之间的差异无统计学意义。最常见的精神障碍依次为酒精使用障碍(5.55%)、心境恶劣障碍(1.99%)、重性抑郁障碍(1.50%)和精神分裂症(1.12%)。有精神障碍者中仅10.53%曾因心理问题在医疗机构就诊,但仅7.69%曾在精神科就诊。结论:精神卫生问题,特别是酒精使用障碍、重性抑郁障碍、心境恶劣障碍和精神分裂症,已成为山东省突出的公共卫生问题。     

Evidence from brain imaging with fMRI supporting functional specificity of acupoints in humans

We tested whether the stimulation of acupoints in the same spinal segments could induce different central responses with functional magnetic resonance imaging (fMRI) study. Stimulation of acupoints ST36/SP6 (Zusanli/Sanyinjiao) or GB34/BL57 (Yanglingquan/Chengshan) both activated primary and secondary somatosensory area, insula, ventral thalamus, parietal Brodmann Area 40, temporal lobe, putamen, and cerebellum, while de-activated amygdala. Nevertheless, ST36/SP6 stimulation specifically activated orbital frontal cortex and de-activated hippocampus. Alternatively, stimulation of GB34/BL57 activated dorsal thalamus and inhibited those of primary motor area and premotor cortex. Thus, stimulation of acupoints in the same spinal segments induced distinct though overlapped cerebral response patterns, which indicated the existence of acupoint specificity.     

Rats with decreased brain cholecystokinin levels show increased responsiveness to peripheral electrical stimulation-induced analgesia

Using the P77PMC strain of rat, which is genetically prone to audiogenic seizures, and also has decreased levels of cholecystokinin (CCK), we examined the analgesic response to peripheral electrical stimulation, which is, in part, opiate-mediated. A number of studies have suggested that CCK may function as an antagonist to endogenous opiate effects. Therefore, we hypothesized that the P77PMC animals would show an enhanced analgesic response based on their decreased CCK levels producing a diminished endogenous opiate antagonism. We found that the analgesic effect on tail flick latency produced by 100 Hz peripheral electrical stimulation was more potent and longer lasting in P77PMC rats than in control rats. Moreover, the potency of the stimulation-produced analgesia correlated with the vulnerability to audiogenic seizures in these rats. We were able to block the peripheral electrical stimulation-induced analgesia (PSIA) using a cholecystokinin octapeptide (CCK-8) administered parenterally. Radioimmunoassay showed that the content of CCK-8 in cerebral cortex, hippocampus and periaqueductal gray was much lower in P77PMC rat than in controls. These results suggest that low CCK-8 content in the central nervous system of the P77PMC rats may be related to the high analgesic response to peripheral electrical stimulation, and further support the notion that CCK may be an endogenous opiate antagonist.     

Is cholecystokinin octapeptide (CCK-8) a candidate for endogenous antiopioid substrates?

Cholecystokinin octapeptide (CCK-8), given intracerebroventricularly (icv) or intrathecally (ith) at the dose range of 0.25-4.0 ng, dose-dependently antagonised the effect of morphine analgesia and electroacupuncture analgesia (EAA) in the rat. That CCK-8 antiserum was capable of reversing the tolerance to EAA and changing the non-responders of EAA into responders suggest CCK-8 to be the endogenous anti-opioid substrate and that blocking the effect of CCK-8 may prove to be a powerful way of augmenting the effect of morphine analgesia and EA analgesia.     

Acupuncture and endorphins

Acupuncture and electroacupuncture (EA) as complementary and alternative medicine have been accepted worldwide mainly for the treatment of acute and chronic pain. Studies on the mechanisms of action have revealed that endogenous opioid peptides in the central nervous system play an essential role in mediating the analgesic effect of EA. Further studies have shown that different kinds of neuropeptides are released by EA with different frequencies. For example, EA of 2 Hz accelerates the release of enkephalin, beta-endorphin and endomorphin, while that of 100 Hz selectively increases the release of dynorphin. A combination of the two frequencies produces a simultaneous release of all four opioid peptides, resulting in a maximal therapeutic effect. This finding has been verified in clinical studies in patients with various kinds of chronic pain including low back pain and diabetic neuropathic pain.     

Repeated peripheral electrical stimulations suppress both morphine-induced CPP and reinstatement of extinguished CPP in rats: accelerated expression of PPE and PPD mRNA in NAc implicated

Previous studies have shown that peripheral electrical stimulation (PES) can suppress morphine-induced conditioned place preference (CPP) and the reinstatement of extinguished CPP in the rat. The present study was performed to elucidate if preproenkephalin (PPE) and preprodynorphin (PPD) mRNAs in the nucleus accumbens (NAc) play a role in this event. Rats were trained with morphine for 4 days to establish CPP paradigm. They were then given 15-min test once a day for eight consecutive days for extinction trial. Twenty-four hours after the 8th session of extinction trials, rats were given peripheral electrical stimulation (PES) at 2 or 100 Hz once a day for 3 days, then a morphine-priming injection at a dose of 1, 2, or 4 mg/kg to reinstate the extinguished CPP. At the end of the experiment, PPE and PPD mRNA levels in the nucleus acccumbens (NAc) were determined by the semiquantitative RT-PCR technique. The results showed that PES at 2- and 100-Hz administered 30 min a day for 3 days suppressed both the expression of morphine-induced CPP and the reinstatement of extinguished CPP. PES at 2 Hz increased preproenkephalin (PPE) mRNA levels, whereas PES of 100 Hz that of preprodynorphin (PPD) mRNA levels in the NAc. These findings suggest that enkephalin and dynorphin in NAc may play important roles in the mechanisms underlying the inhibitory effect of PES on the expression and reinstatement of morphine-induced CPP in rats.     

Hyperpolarization-activated, cyclic nucleotide-gated cation channels: roles in the differential electrophysiological properties of rat primary afferent neurons

The large, medium-sized, and small neurons of the dorsal root ganglion (DRG) have different functions in the processing of various senses. Hyperpolarization-activated, cyclic nucleotide-gated channels (HCN) contribute greatly to neuronal excitability. In the present study, which used whole-cell patch clamp techniques and immunohistochemical staining methods, the electrophysiological properties of DRG neurons were systematically compared, and the roles of HCN-1, -2, and -4 were examined. The main results were as follows. 1) The large neurons had significantly higher V0.5 values (membrane potential at which the HCN channels were half-activated) and shorter time constants (tau) than small or medium-sized DRG neurons. However, large DRG neurons had higher Ih density (HCN neuron current). 2) HCN-1 was found predominantly, but not exclusively, in large and medium-sized DRG neurons; HCN-2 was found in all DRG neurons; and HCN-4 was poorly visualized in all DRG neurons. HCN-1 and HCN-2 were colocalized in large and medium-sized neurons with immunostaining of adjacent sections. In the dorsal horn of the spinal cord, HCN-1, HCN-2, and HCN-4 were all expressed in laminae I-IV, although HCN-1 was not detectable in lamina II. 3) Blockade of Ih current in DRG neurons caused a significant decrease in V0.5, resting membrane potential, and repetitive firing number of action potential and a significant increase in time of rising phase of action potential. These results suggest that the different HCN channels in the three types of DRG neurons might contribute to their differential electrophysiological properties.     

肝细胞生长因子与三七总皂甙对自体肝细胞脾内移植的影响(英文)

目的:探索通过促进肝细胞DNA合成及对抗缺血再灌注损伤以加速肝化脾增量及缩短其再生周期的新途径。方法:应用肝细胞生长因子(PHGF)与三七总皂甙(PNG)于自体肝细胞脾内移植(IHAT)的动物模型上,分别于移植术后2周、12周对病理组织学、电镜形态、肝化脾匀浆谷丙转氨酶(ALT)含量、~(99m)Tc-HIDA摄取试验及脾内肝细胞增殖指数等进行观察分析。结果:移植术后2周,三七总皂甙组脾内肝细胞水肿、变性程度较轻,肝化脾匀浆ALT含量达(928±268)U/g,明显高于对照组(P<0.05);移植术后12周,肝细胞生长因子组脾内肝细胞生长好,数量、面积大,肝化脾匀浆ALT含量达(2325±401)U/g,增殖指数达3.8％±0.3％。对照组分别为(1839±368)U/g,2.9％±0.4％,P<0.05,且在~(99m)Tc-HIDA摄取试验中PHGF组离体肝化脾显影较清晰,其放射性计数明显高于对照组(P<0.05)结论:PNGS在移植早期对脾内肝细胞有一定的抗损伤保护作用,而PHGF对加速肝化脾增量及缩短其再生周期有明显作用。