Denaturing high-performance liquid chromatography coupled with multiplex PCR for rapid detection of large duplications or deletions in patients with Duchenne muscular dystrophy and spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the value of multiplex PCR-denaturing high-performance liquid chromatography (PCR-DHPLC) method for screening large duplications or deletions in patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA).</p><p><b>METHODS</b>DNA was extracted from peripheral venous blood samples from 35 DMD and 6 SMA patients. Large duplications or deletions were screened with multiplex PCR coupled with DHPLC method. The results were validated with testing of positive and negative controls.</p><p><b>RESULTS</b>Known duplications or deletions in all controls were reliably detected with multiple PCR coupled with DHPLC. Large duplications or deletions were found in 71.4% of 35 DMD patients, which included 5 large duplications and 20 large deletions. For SMA patients, deletions of SMN1 exon 7 were detected in 16 samples.</p><p><b>CONCLUSION</b>Multiplex PCR coupled with DHPLC method is an effective and reliable method for detecting large genomic duplications or deletions in patients with DMD or SMA.</p>

Effect of radiofrequency of different temperatures and durations on motor conduction velocity of rat sciatic nerve / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of radiofrequency of different temperatures and durations on sciatic nerve motor conduction velocity (MCV).</p><p><b>METHODS</b>The bilateral sciatic nerve of 70 adult SD rats was dissected and exposed to radiofrequency ablation of different temperatures (30, 50, 55, 60, and 70 degrees C) and durations. The nerves were also exposed to increasing ablation temperatures from 30 degrees C to 50 degrees C with an increment of 5 degrees C (60 s at each temperature), and the changes in the MCV parameters were observed.</p><p><b>RESULTS</b>The MCV parameters of rat sciatic nerve underwent significant changes following the radiofrequency exposures (P<0.05) except for the exposure at 55 degrees celsius; for 10 s. Below the temperature of 55 degrees celsius;, the MCV showed no obvious correlation to the exposure time for the group. For the nerves exposed to radiofrequency of 55 degrees celsius;, the latency was not correlated to the exposure time within 30 s, and data could be obtained from 55 s group; with these exceptions, the latency was found to positively while the negative phase wave inversely correlated to the exposure time. With fixed exposure time of 60 s, the MCV parameters were positively correlated to the ablation temperature (below 50 degrees C). Failure of MCV measurement occurred following exposures to 55 degrees celsius; for 50 s (or longer) or to 60 degrees C (or higher) for 10 s.</p><p><b>CONCLUSION</b>Low-temperature radiofrequency (below 50 degrees C) produces definite effects on the MCV of rat sciatic nerve, and the effects are not associated with the exposure time, the mechanism of which remains unclear. At a given temperature, the ablation for sufficiently long durations can result in complete block of the MCV. At higher temperatures, radiofrequency exposure cause obvious nerve conduction block.</p>

Analgesic effects of chemical lumbar sympathectomy on refractory pain in the lower limbs / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of chemical lumbar sympathectomy (CLS) on relieving refractory pain in the lower limbs.</p><p><b>METHODS</b>Twenty-four patients with refractory pain in the lower limbs underwent CLS under X-ray guidance, and 2 ml contrast agent was injected at 1/3 of the second L2 vertebrae (the L2 sympathetic ganglion). Lidocaine was then injected followed by injection of 7% phenol for performing CLS. The visual analog scale was used to assess the pain severity before and after CLS. The effect of CLS on relieving lower limb pain was compared with that of oral pain-relieving medication.</p><p><b>RESULTS</b>The lower limb pain was obviously relieved as shown by significantly decreased VAS scores in these patients after CLS. CLS exhibited a much more potent effect of pain relief in the lower limbs than the oral medication.</p><p><b>CONCLUSION</b>CLS produces significant analgesic effects to relieve refractory pain in the lower limbs.</p>

Inhibiting effect of vagal nerve stimulation to seizures in epileptic process of rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>Our previous work suggested that sensitivity of hippocampal neurons is changed in process of epileptic activities, and closely parallel to the dynamic characteristic of epileptic activity of the neurons. This study investigated the sensitivity of epileptic brain to vagal nerve stimulation (VNS) in epileptic process.</p><p><b>METHODS</b>Epileptic model was evoked by penicillin. Left vagal nerves were stimulated to inhibit the seizures induced by penicillin. The electrocorticography (ECoG) and electromyography (EMG) were recorded to analyze inhibiting effect of VNS in epileptic process.</p><p><b>RESULTS</b>It was found that VNS could inhibit the seizures caused by penicillin, and the inhibiting effect of VNS to seizures increased as the vagal nerve stimulating time prolonged. It was also found that the inhibiting effect of VNS to seizures decreased in epileptic process.</p><p><b>CONCLUSION</b>The results suggested that the sensitivity of epileptic brain to VNS was different in epileptic process. The inhibiting effect of VNS to seizure decreased as the development of seizures.</p>

Botulinum toxin type A does not affect spontaneous discharge but blocks sympathetic-sensory coupling in chronically compressed rat dorsal root ganglion neurons / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of botulinum toxin type A (BTXA) on spontaneous discharge and sympathetic- sensory coupling in chronically compressed dorsal root ganglion (DRG) neurons in rats.</p><p><b>METHODS</b>In chronically compressed rat DRG, spontaneous activities of the single fibers from DRG neurons were recorded and their changes observed after BTAX application on the damaged DGR. Sympathetic modulation of the spontaneous discharge from the compressed DRG neurons was observed by electric stimulation of the lumbar sympathetic trunk, and the changes in this effect were evaluated after intravenous BTXA injection in the rats.</p><p><b>RESULTS</b>Active spontaneous discharges were recorded in the injured DRG neurons, and 47 injured DRG neurons responded to Ca2+-free artificial cerebrospinal fluid but not to BTXA treatment. Sixty-four percent of the neurons in the injured DRG responded to sympathetic stimulation, and this response was blocked by intravenously injection of BTXA.</p><p><b>CONCLUSION</b>BTXA does not affect spontaneous activities of injured DRG neurons, but blocks sympathetic-sensory coupling in these neurons.</p>