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>

Cognitive function in PD patients without dementia / 中华神经医学杂志

Objective To analyze the characteristics of cognitive function impairment in PD patients without dementia and their influencing factors, and provide evidence for early recognition and treatment of cognitive deficits in PD patients. Methods Fifty-six PD patients without dementia,admitted to our hospital from January 2010 to October 2011 were assessed with mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) for cognitive function. Logistic stepwise regression was employed to analyze the influencing factors of cognitive function impairment.Results Using MMSE scores as the standard for recognition, PD patients with mild cognitive impairment (MCI) accounted for 7.14％ (6/56); however,using MoCA scores,they accounted for 71.43％(40/56). Both of the MMSE and MoCA scores were positively correlative with the education degree of the patients (r=0.483,P=-0.007; r=0.503,P=0.000).In the cognitive domain of MMSE,the scores of visuospatial function,and abilities of delayed recall,calculation,attention and repetition had significant decrement; and MMSE indicated that abilities of delayed recall, immediate memory, calculation and attention,and visuospatial function were main cognitive disturbances of PD.In the cognitive domain of MoCA,the scores of visuospatial and executive functions,and abilities of delayed recall,abstraction and repetition had significant decrement; MoCA indicated that visuospatial and executive functions,abilities of delayed recall,denomination,attention,abstraction and repetition were main cognitive disturbances of PD. Logistic regression analysis showed that education degree and clinical types were the main influencing factors of cognitive function impairment in PD patients. Conclusion Cognitive impairment is very common in patients with PD,and the main cognitive deficits involve visuospatial and executive functions,abilities of delayed recall,calculation,attention,abstraction and repetition; education degree and clinical types are the influencing factors of cognitive impairment of PD.

Mechanism of platelet anti-aggregation with Ginkgo biloba extract / 中华神经医学杂志

Objective To investigate the effect of Ginkgo biloba extract (EGB) on changes of activities of platelet phosphodiesterase (PDE) and nucleotide cyclase (adenylate cyclase [AC] and guanylate cyclase [GC]), and levels of cyclic nucleotide (cylic adenosine monophosphate [cAMP] and cyclic guanosine monophosphate [cGMP]), and investigate the mechanism of platelet anti-aggregation with EGB. Methods Blood samples from 3 healthy volunteers, not taken any drugs within 2 weeks of the experiments, were anticoagulated with 3.8% sodium citrate. After isolating and washing, platelet was given various concentrations of EGB, and then applied for measurement of the levels cAMP and cGMP and the activities of PDE, AC and GC isolated from platelet sonic homogenates. Controls were given the same volume of bulk drug solvent. Results EGB dose-dependence was noted: the higher the level of EGB, the higher the cAMP level and the more active the PDE3. EGB at high-dose could slightly inhibit the PDE5 activity. EGB in any dosages could not affect the cGMP level, and activities of PDE2, AC and GC. Conclusion EGB has platelet anti-aggregation effect through inhibiting the PDE3 activity and increasing the cAMP level.

Changes of platelet phosphodiesterase activity in patients with acute cerebral infarction and its influencing factors / 中华神经医学杂志

Objective To observe the changes of activities of platelet phosphodiesterase(PDE)subtypes in patients with acute cerebral infarction,and explore their influencing factors.Methods The platelet PDE activity,cyclic nucleotide level and[Ca2+]i concentration of 30 patients with acute cerebral infarction were detected on the 1st, 4th,8th and 15th d of onset.Ten healthy individuals of the same age ranges were chosen as control group.Results On the 1st,4th and 8th d of onset,as compared with those in the healthy individuals,the activities of platelet PDE2 and PDE3 and the level of cyclic adenosine monophosphate(cAMP)were obviously decreased,and the[Ca2+]i level was significantly increased in patients with acute cerebral infarction(P<0.05); while the PDE5 activity and cyclic gnanosine monophosphate(cGMP)level in patients with acute cerebral infarction did not change obviously.[Ca2+]iwas linearly correlated with cAMP(R2=0.921,P<0.05);however,the activities of PDE2 and PDE3 showed no correlation with both levels of[Ca2+]i and cAMP. Conclusion Decreased cAMP level and increased[Ca2+]i concentration are noted in patients with acute cerebral infarction,and the platelet is activated at this time points.Platelet PDE2 and PDE3 play protect roles in acute cerebral infarction through decreasing their activities,slowing the cAMP decreased level and inhibiting the activity of platelet.

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>

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>

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>