Cortical plasticity: effect of high and low intensity conditioning electrical stimulations (100 Hz) on SEPs to painful finger stimulation.

OBJECTIVE: To study the effect of high-frequency (100 Hz) repetitive conditioning electrical stimulation (CES, 10 min) on human somatosensory evoked potentials (SEPs) to evaluate if short-term cortical plasticity could be induced. METHODS: Painful electrical stimulations were applied to thumb (D1) and little finger (D5) fingertips, respectively. The 124-channel EEG was recorded from 10 healthy male volunteers. Peak stages around 34, 45, 212, 331 ms were analyzed with focal maximum amplitude (FA) and area magnitude (AM) of scalp field potential, topography, and equivalent current dipole source localisation, comparing before and after two-level CES (high- vs. low-level) applied to the He-Gu acupoint. RESULTS: After a high-level CES, the positive FA and AM of the current efflux showed a significant increase at the early phase 34 ms, and significantly decreased at 45 ms in D1 SEPs. The negative FA and AM of the current influx were significantly increased at late phase 350 ms of the D5 SEPs. Only 36 ms, the z-axis position of dipole was significantly changed from (x: -15.9 mm, y: 29.6 mm, z: 43.9 mm) to (x: -12.9 mm, y: 29.4mm, z: 51.5mm) for the D5 SEPs. CONCLUSIONS: The high-level CES significantly attenuated the subsequent cortical activation (45 ms peak for D1 stimulation). Both low- and high-level CES significantly enhanced the late activities (226, 350 ms) in D5 stimulation. This may be explained by pain sensation change at the level of subcortical cingulate cortex induced by the site-dependent post-effect of CES. SIGNIFICANCE: This study showed cortical plasticity induced by conditioning somatosensory stimulation.     

Recombinant AAV-mediated HSVtk gene transfer with direct intratumoral injections and Tet-On regulation for implanted human breast cancer

Background  

HSVtk/ganciclovir (GCV) gene therapy has been extensively studied in tumors and relies largely on the gene expression of HSVtk. Most studies, however, have failed to demonstrate any significant benefit of a controlled gene expression strategy in cancer treatment. The Tet-On system is commonly used to regulate gene expression following Dox induction. We have evaluated the antitumor effect of HSVtk/ganciclovir gene therapy under Tet-On regulation by means of adeno-associated virus-2 (AAV-2)-mediated HSVtk gene transfer with direct intratumoral injections in mice bearing breast cancer tumors.     

经皮激光椎间盘减压术治疗椎间盘源性腰痛

目的探讨经皮激光椎间盘减压术（percutaneous laser disc decompression，PLDD）治疗椎间盘源性腰痛的疗效。方法2002年6月～2004年12月我院对36例椎间盘源性腰痛，采用英国DIOMED公司半导体激光仪，激光功率15W，每个激光脉冲持续1s，间隔1s，照射能量800～1200J。VAS评分评价治疗效果。结果手术时间15～60min，平均30min。32例出现“疼痛复制效应”。36例随访6～36个月，平均11个月，32例有效（术后VAS评分改善≥3分18例，≥分14例），4例无效，有效率88．9％（32／36）。结论PLDD治疗椎间盘源性腰痛安全、有效、微创。