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ABSTRACT: To evaluate the effect of radiofrequency of different temperatures and durations on sciatic nerve motor conduction velocity (MCV).
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.
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.
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.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 03/2010; 30(3):579-83.
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ABSTRACT: The protein and mRNA expression of focal adhesion plaque associated cytoskeletons, including talin, vinculin, paxillin, and tensin, was studied using immunofluorescence in combination with confocal laser scanning microscopy and fluorescent quantitative polymerase chain reaction in 41 matched samples of human normal colorectal mucosae, primary colorectal adenocarcinomas, and 19 separate lymph node metastases. All specimens showed expression. The results showed talin, vinculin, tensin, and paxillin expression were correlated with carcinogenesis, invasion, and metastasis of colorectal carcinoma (CRC). Talin, vinculin, and tensin underwent downregulation while paxillin went up. So these cytoskeletons may play bidirectional regulating roles during the progression of CRC.
Cancer Investigation 11/2009; 28(2):127-34. · 1.85 Impact Factor
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ABSTRACT: To evaluate the effect of chemical lumbar sympathectomy (CLS) on relieving refractory pain in the lower limbs.
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.
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.
CLS produces significant analgesic effects to relieve refractory pain in the lower limbs.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 12/2008; 28(11):1968-70.
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ABSTRACT: 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.
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.
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.
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.
Neuroscience Bulletin 12/2007; 23(6):336-40. · 1.31 Impact Factor
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ABSTRACT: 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.
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.
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.
BTXA does not affect spontaneous activities of injured DRG neurons, but blocks sympathetic-sensory coupling in these neurons.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 12/2007; 27(11):1638-41.
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ABSTRACT: To evaluate the frequency of microsatellite instability (MSI) and absence of hMLH1/hMSH2 expression in young patients with colorectal cancer, and investigate their role in screening hereditary nonpolyposis colorectal cancer (HNPCC).
Seventy-three young patients (below 40 years old) with colorectal cancer were examined for DNA mismatch repair deficiency by microsatellite testing and immunohistochemical detection of hMLH1/hMSH2 gene products.
The frequency of MSI and absence rate of hMLH1/hMSH2 expression are 56.16% and 49.32% in these patients, respectively, which increased significantly with younger age for cancer diagnosis.
Defects in the DNA mismatch repair system are frequent in Chinese young patients with colorectal cancer. Microsatellite analysis and immunohistochemical detection are useful for efficient identification of HNPCC in these young patients.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 07/2007; 27(6):779-82.
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ABSTRACT: To study the effects of acetylcholine (ACh) on spontaneous discharges of compressed rat dorsal root ganglion (DRG) neurons.
In chronically compressed DRG model, the spontaneous discharge of a single fiber from the DRG neuron in response to ACh treatment was recorded.
Active spontaneous discharges were recorded in the injured DRG, and 77.9% of the injured DRG neurons responded to Ach treatment in the manner of simple excitation, or excitation followed by inhibition. The responses were enhanced with the increase of Ach concentration.
Injured DRG remains active in spontaneous discharges, which can be significantly influenced by ACh treatment.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 12/2006; 26(11):1568-70.
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ABSTRACT: Objective The relationship between firing pattern and sensitivity of neurons was studied in chronically compressed dorsal root ganglion (DRG) neurons and the Hindmarsh-Rose (HR) neuronal model. Methods Spontaneous activities from single fibers of chronically compressed DRG neurons in rats were recorded, and divided into periodic and non-periodic firing patterns. The sensitivity of the two kinds of firing pattern neuron to sympathetic stimulation (SS) was compared. Result It was found that 27.3% of periodic firing neurons and 93.2% of non-periodic firing neurons responded to SS respectively (periodic vs non-periodic, P < 0.01). The responses to SS with different stimulation time were greater non-periodic firing neurons than periodic firing neurons (P < 0.01). The non-periodic firing neurons obviously responded to SS. After the firing pattern of these neurons transformed to periodic firing pattern, their responses to SS disappeared or decreased obviously. The HR neuronal model exhibited a significantly greater response to perturbation in non-periodic (chaotic) firing pattern than in periodic firing pattern. Conclusion The non-periodic firing neurons with deterministic chaos are more sensitive to external stimuli than the periodic firing neurons.
Neuroscience Bulletin 01/2006; 22(1):14-20. · 1.31 Impact Factor
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ABSTRACT: To study the responses of injured dorsal root ganglion (DRG) neurons to sympathetic nerve stimulation with different time sequences.
In chronically compressed DRG model, the spontaneous activity of the single fiber from injured DRG neurons was recorded, and the responses of DRG neurons to chaotic and periodic electric stimulation of the lumbar sympathetic trunk compared.
Sympathetic-sensory coupling was present in chronically compressed DRG neurons, and the response of DRG neurons increased gradually as the sympathetic stimulating frequency increased from 5 to 20 Hz (P<0.01). The chaotic stimulation evoked much greater response than periodic stimulation, even though the stimulating frequency was similar (P<0.01).
Besides the stimulating frequency, the time sequence of the stimulation is one of the important factors that influence the response of DRG neurons to sympathetic stimulation. Chaotic sympathetic stimulation causes greater response than periodic stimulation does, and the chaotic activity of presynaptic neuron evokes greater postsynaptic response than periodic activity. The chaotic activity of the neurons might be one of the effective ways for information transmission through the nerves.
Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 12/2003; 23(11):1181-3, 1187.
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ABSTRACT: To study the correlation between the expression of integrin alpha5beta1 in colorectal carcinomas and the differentiation and metastasis of the tumor cells.
The expression levels of integrin alpha5beta1 were detected immunohistochemically in 81 pairs of cancerous and non-cancerous tissues of patients with colorectal cancer.
The expression of integrin alpha5beta1 was significantly higher in the samples of colorectal carcinomas, than in non-cancerous tissues (P<0.05). Lower expression levels were detected in moderately or well differentiated colorectal carcinomas than in poorly differentiated ones (P<0.05). No significant relation was noted between the expression of integrin alpha5beta1 and lymph node metastasis of the colorectal carcinomas (P>0.05).
Alpha5beta1 expression is significantly associated with the carcinogenesis and differentiation of colorectal carcinomas, but not with their lymph node metastasis, and the expression level might be used as a valuable pathological indicator for the carcinogenesis and progression of colorectal carcinomas.
Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 08/2003; 23(8):806-8.
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Zhonghua bing li xue za zhi Chinese journal of pathology 05/2003; 32(2):158-61.
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ABSTRACT: Our previous works suggested that sensitivity of neurons with chaotic firing patterns to stimuli is significantly greater than that in neurons with periodic firing patterns, which shows that responsiveness of neurons may depend on the complexity of the firing series. This study was performed to determine the relation between responsiveness of the hippocampal CA1 neurons with epileptiform activity (EA) to neurotransmitters and their complexity of firing series.
Firing series of CA1 neurons were recorded extracellularly in rat hippocampal slice. Approximate entropy was used to describe the complexity of the interspike interval (ISI) series. EA was induced by local application of penicillin (1,000 IU/ml). The change of firing rate induced by neurotransmitters (glutamate and gamma-aminobutyric acid) was compared with that of the degree of complexity of ISI series in the process of EA.
The excitatory responses to glutamate and the inhibitory responses to gamma-aminobutyric acid in CA1 neurons appeared to be decreased during the process of penicillin-induced EA. However, during this same process, the approximate entropy of the ISI series also was decreased significantly.
The results suggest that the reduced responses to neurotransmitters of the CA1 neurons appear to be closely related to the onset of EA. Furthermore, these neurons show that the changes in responsiveness are closely parallel to the decrease of degree of complexity of firing series during penicillin epileptogenesis.
Epilepsia 12/2002; 43(11):1330-6. · 3.96 Impact Factor
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ABSTRACT: OBJECTIVE: To study the effect of vagal nerve stimulation in seizure inhibition in rats. METHODS: In rat epileptic models induced by penicillin, electromyogram (EMG), electroencephalogram (EEG) and extracellular electric activity of the cortex were recorded to study the inhibiting effect of vagal nerve stimulation on epilepsy. Results Inhibiting effect of vagal nerve stimulation on epilepsy was observed from the changes in behavior, EMG, EEG and extracellular electric activity of the rats, and this inhibiting effect was enhanced as the frequency for stimulation increased from 5 Hz to 20 Hz. Conclusion Vagal nerve stimulation can inhibit the epileptic activity in rats, the effect of which depends on the stimulation conditions imposed on the rats.
Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 09/2002; 22(8):716-8.
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ABSTRACT: An interesting phenomenon that aperiodic firing neurons have a higher sensitivity to drugs than periodic firing neurons have been reported for the chronically compressed dorsal root ganglion neurons in rats. In this study, the dynamical mechanisms for such a phenomenon are uncovered from the viewpoint of dynamical systems theory. We use the Rose–Hindmarsh neuron model to illustrate our opinions. Periodic orbit theory is introduced to characterize the dynamical behavior of aperiodic firing neurons. It is considered that bifurcations, crises and sensitive dependence of chaotic motions on control parameters can be the underlying mechanisms. And then, a similar analysis is applied to the modified Chay model describing the firing behavior of pancreatic beta cells. The same dynamical mechanisms can be obtained underlying that aperiodic firing cells are more sensitive to external stimulation than periodic firing ones. As a result, we conjecture that sensitive response of aperiodic firing cells to external stimulation is a universal property of excitable cells.
Chaos Solitons & Fractals 22(1):151-160. · 1.22 Impact Factor
