Long pulse gastric electrical stimulation induces regeneration of myenteric plexus synaptic vesicles in diabetic rats

Background Gastric electrical stimulation (GES) may improve delayed gastric emptying in diabetic gastroparesis, but whether enteric nervous system (ENS) is directly involved in its mechanism of improvement in gastric motility is unclear. The aims were to investigate the correlation between the changes in ENS and effects of long pulse GES on them in diabetic rats induced by streptozotocin (STZ). Methods Electron microscopy, immunohistochemistry, RT‐PCR and western blot were used to evaluate changes of myenteric plexus neurons and synaptic vesicles in different stages of the diabetic rats. The effects of GES were detected by same methods after pacing wires were implanted and then diabetes was induced and followed by long pulse GES. Key Results Since 6 weeks after STZ injection, the nerve fibres were incompact and synaptic vesicles in myenteric neurons reduced. Furthermore, the myenteric neurons showed severe damage such as partial depletion of the axon, swelling of mitochondria and seriously decreased synaptic vesicles in 12 weeks after STZ injection. The synaptophysin and PGP9.5‐positive area and expressions of synaptophysin mRNA and protein decreased with the duration of diabetes. Long pulse GES could induce increase of myenteric neuronal synaptic vesicles, synaptophysin and PGP9.5‐positive area and in myenteric plexus. The synaptophysin mRNA and protein expression rose after GES, whatever GES beginning early or late, short‐term or long‐term. Conclusions & Inferences The longer duration of diabetes, the more significant damages to myenteric neurons and synaptic vesicles of diabetic rats; long pulse GES could induce regeneration of myenteric plexus synaptic vesicles, thereby reform gastric motility.     

Environmental enrichment potentiates thalamocortical transmission and plasticity in the adult rat visual cortex

It has been demonstrated that the complex sensorimotor and social stimulation achieved by rearing animals in an enriched environment (EE) can reinstate juvenile‐like plasticity in the adult cortex. However, it is not known whether EE can affect thalamocortical transmission. Here, we recorded in vivo field potentials from the visual cortex evoked by electrical stimulation of the dorsal lateral geniculate nucleus (dLGN) in anesthetized rats. We found that a period of EE during adulthood shifted the input–output curves and increased paired‐pulse depression, suggesting an enhanced synaptic strength at thalamocortical terminals. Accordingly, EE animals showed an increased expression of the vesicular glutamate transporter 2 (vGluT‐2) in geniculocortical afferents to layer IV. Rats reared in EE also showed an enhancement of thalamocortical long‐term potentiation (LTP) triggered by theta‐burst stimulation (TBS) of the dLGN. To monitor the functional consequences of increased LTP in EE rats, we recorded visual evoked potentials (VEPs) before and after application of TBS to the geniculocortical pathway. We found that responses to visual stimulation were enhanced across a range of contrasts in EE animals. This was accompanied by an up‐regulation of the intracortical excitatory synaptic marker vGluT‐1 and a decrease in the expression of the vesicular GABA transporter (vGAT), indicating a shift in the excitation/inhibition ratio. Thus, in the adult rat, EE enhances synaptic strength and plasticity of the thalamocortical pathway associated with specific changes in glutamatergic and GABAergic neurotransmission. These data provide novel insights into the mechanisms by which EE shapes the adult brain. © 2010 Wiley‐Liss, Inc.     

Increased glutamate in the hippocampus after galantamine treatment for Alzheimer disease

Galantamine is a cholinesterase inhibitor and allosteric potentiating ligand modulating presynaptic nicotinic acetylcholine receptors that is used in the treatment of Alzheimer disease (AD). The purpose of this study was to determine if galantamine treatment would result in detectable hippocampal metabolite changes that correlated with changes in cognition, as measured by the Mini-Mental State Examination (MMSE) and the Alzheimer Disease Assessment Scale-cognitive subscale (ADAS-cog). Short echo-time proton magnetic resonance (MR) spectra were acquired from within the right hippocampus of ten patients using a 4 Tesla magnetic resonance imaging (MRI) scanner. Spectra were used to quantify absolute metabolite levels for N-acetylaspartate (NAA), glutamate (Glu), choline (Cho), creatine (Cr), and myo-inositol (mI). Patient scans and cognitive tests were performed before and 4 months after beginning galantamine treatment, which consisted of an 8 mg daily dose for the first month and a 16 mg daily dose for the remaining three months. The levels of Glu, Glu/Cr, and Glu/NAA increased after four months of treatment, while there were no changes in MMSE or ADAS-cog scores. Additionally, changes (Δ) in Glu over the four months (ΔGlu) correlated with ΔNAA, and Δ(Glu/Cr) correlated with ΔMMSE scores. Increased Glu and the ratio of Glu to Cr measured by MR spectroscopy after galantamine treatment were associated with increased cognitive performance. The increase in Glu may be related to the action of galantamine as an allosteric potentiating ligand for presynaptic nicotinic acetylcholine receptors, which increases glutamatergic neurotransmission.     

高血压病合并脑梗死患者的踝臂脉搏波传导速度研究

目的探讨踝臂脉搏波传导速度（baPWV）与高血压病继发脑梗死的相关性。方法对94例原发性高血压伴急性脑梗死患者和113例无脑卒中的高血压病患者进行baPWV检测,并分组对比分析。结果脑梗死组右侧baPWV（RbaPWV）均值为（2180．6±556．8）cm／s,左侧baPwv（LhaPwV）均值为（2177．1±575．0）cm／s;无脑卒中组baPWV均值分别为（1894．5±430．4）cm／s和（1903．8±438．4）cnds。脑梗死组baPWV明显高于无脑卒中组,差异有非常显著意义（P〈0．001）。结论baP—WV能反映高血压病患者脑部动脉的病变程度,与脑梗死的发生密切相关。     

Reactive oxygen species levels and DNA fragmentation on astrocytes in primary culture after acute exposure to low intensity microwave electromagnetic field

The exposure of primary rat neocortical astroglial cell cultures to acute electromagnetic fields (EMF) in the microwave range was studied. Differentiated astroglial cell cultures at 14 days in vitro were exposed for 5, 10, or 20 min to either 900 MHz continuous waves or 900 MHz waves modulated in amplitude at 50 Hz using a sinusoidal waveform and 100% modulation index. The strength of the electric field (rms value) at the sample position was 10 V/m. No change in cellular viability evaluated by MTT test and lactate dehydrogenase release was observed. A significant increase in ROS levels and DNA fragmentation was found only after exposure of the astrocytes to modulated EMF for 20 min. No evident effects were detected when shorter time intervals or continuous waves were used. The irradiation conditions allowed the exclusion of any possible thermal effect. Our data demonstrate, for the first time, that even acute exposure to low intensity EMF induces ROS production and DNA fragmentation in astrocytes in primary cultures, which also represent the principal target of modulated EMF. Our findings also suggest the hypothesis that the effects could be due to hyperstimulation of the glutamate receptors, which play a crucial role in acute and chronic brain damage. Furthermore, the results show the importance of the amplitude modulation in the interaction between EMF and neocortical astrocytes.     

0.5 mT工频磁场对小鼠海马CA3区锥体神经元延迟整流钾离子通道和动作电位的影响

目的 研究与日常生活密切相关的0.5 mT工频磁场对小鼠海马CA3区锥体神经元的影响.方法 采用急性分离的方法制备小鼠海马CA3区锥体神经元,用0.5 mT、50 Hz磁场对小鼠海马CA3区锥体神经元刺激30 min后,运用全细胞膜片钳技术研究其延迟整流钾通道电流,Ik和动作电位特性.结果 0.5 mT工频磁场照射小鼠海马CA3区锥体神经元30 min后,其电流密度减小,对照组和曝磁组最大电流密度分别为（171.05＋1.32）pA/pF、（139.65±2.37）pA/pF（n=12,P〈0.05）;对照组和曝磁组半数激活电压分别为（7.44±0.64）mV、（34.09＋6.48）mV（n=12,P〈0.05）;斜率因子分别为11.36±0.57、19.97±3.45（n=12,P〈0.05）;动作电位复极化时程APD90由（14.63±0.34）ms延长为（21.74±1.47）ms（n=12,P〈0.05）.结论 0.5 mT工频磁场可使小鼠海马CA3区锥体神经元延迟整流钾通道电流Ik减小,通道开放延迟,通道激活速度减慢,动作电位复极化时间延长.     

从“象思维”到脉象地形图

自然界中的一切事物都会展现出自己的"象",古代医家根据对"象"的观察,得出中医理论起源的独特认知方式——"象思维",根源于中医理论,采用"象思维"的方式,提出"脉象地形图"概念,并进行阐释。     

滑脉脉形与主病的文献研究

脉诊自古便是中医极具特色的诊察手段,是医生正确认识疾病的重要途径。历代医家对脉诊尤为重视,脉象专著有上百种之多,脉诊专篇更是不计其数。"滑脉"作为临床中的常见脉象,在历代文献中有大量的理论阐释和临床体会。在研习相关文献时,发现其内容分散、条理繁杂、观点众多,为方便进一步的理论研究并指导临床脉诊,笔者对其进行简要梳理并与近代临床的报道进行对比,以期为滑脉的临床与文献研究提供参考。     

多模式音频脉冲光电治疗仪治疗原发性1级高血压病临床研究

目的:观察多模式音频脉冲光电治疗仪对原发性1级高血压病患者的临床治疗效应。方法:对90例原发性1级高血压病患者进行辨证分型后,将各证型患者随机分入光电音治疗组、单纯针刺组和口服安慰剂组,采用相应治疗。结果:光电音治疗组治疗后降压的总有效率显著优于单纯针刺组(P0.05)和口服安慰剂组(P0.01)。光电音治疗组治疗后症状改善的总有效率显著优于口服安慰剂组(P0.01)。结论:多模式音频脉冲光电治疗仪能有效地降低原发性1级高血压病患者的血压,改善其临床症状。     

伏脉的临床主病

在中医学丰富的诊法中,脉诊是其中重要内容,自古以来都具有举足轻重的作用。伏脉代表自然界在冬季不能把太阳辐射的能量封存在水系统之中,或能量物质不能正常释放而造成的病态现象,伏脉代表了气内实,即热深与痰闭,又代表了气内虚,阳气不升,阴气内闭。临床上见伏脉多与沉、数、迟、弦脉相兼出现,均以有力无力、脉诊合参,判断实证与虚证。笔者通过临证16年,对伏脉的脉象和机理、主病辨析、现代研究与临床意义进行了总结,凡得伏脉,随着时间、空间的推移转化,易患急危重症及疑难病,应高度引起临床的重视。