• The Korean Journal of Pain
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• v.12 no.1
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• pp.8-15
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• 1999

Following peripheral nerve injury, rats will show a tactile allodynia and hyperalgesia. But the mechanism of allodynia is still obscure. The present studies, using rats rendered allodynia by loosely constrictive ligation of the common sciatic nerve (Bennett Model) and tight ligation of L5 & L6 spinal nerve (Chung Model), aimed to investigate the changes of metabotrophic glutamate receptor type 5 on the development of tactile allodynia. Male Sprague-Dawley rats (130~200 g) were anesthetized with halothane, the rats were randomly divided into one of these three groups, Group 1 (Sham operation), Group 2 (Bennett model) and Group 3 (Chung model). Seven days after surgical procedure, the animal was reanesthetized and decapitated. The spinal cord was quickly removed and stored at deep freezer for polymerase chain reaction (RT-PCR). In Group 2&3, rats showed that tactile allodynia checked by up-down method with calibrated 8 von Frey hair. The level of gene expression of mGluR5 mRNA was significantly increased in group 2 and 3. These increases was significantly different from sham operation, group 1. It was also showed that the increasing patterns of group 2 and 3 in the gene expression were similar correlation with the results of the threshold for tactile allodynia on von Frey hair test. Even though there were some differences between Bennett model and Chung model, these results suggested that mGluR5 had partly attributed to making a tactile allodynia from these models.

• The Korean Journal of Physiology
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• v.30 no.2
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• pp.289-297
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• 1996

Excitatory amino acids (EAA) are thought to play an important role in producing cell death associated with ischemic and traumatic spinal cord injury. The present study was carried out to determine if the response characteristics of spinal sensory neurons in segments adjacent to degeneration sites induced by EAA are altered following these morphological changes. Intraspinal injections of quisqualic acid (QA) produced neuronal degeneration and spinal cavitation of gray matter. The severity of lesions was significantly attenuated by pretreatment with a non-NMDA antagonist NBQX. In extracellular single unit recordings, dorsal horn neurons in QA injected animal showed the increased mechanosensitivity, which included a shift to the left in the stimulus-response relationship, an increased background activity and an increase in the duration of after-discharge responses. Neuronal responses, especially the C-fiber response, to suprathreshold electrical stimulation of sciatic nerve also increased in most cases. These results suggest that altered functional states of neurons may be responsible for sensory abnormalities, e.g. allodynia and hyperalgesia, associated with syringomyolia and spinal cord injury.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.90-96
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• 2010

Purpose: The purpose of this study is to investigate the usefulness of ultrasound-guided femorosciatic nerve block by orthopaedist to operate the fracture around ankle. Materials and Methods: Twenty-two patients, who had an operation for fracture around the ankle under a ultrasound-guided femorosciatic nerve block from January to April 2010, were the targets of this study. We measured the time spent for the ultrasound-guided femorosciatic nerve block, the time taken to start the operation after the nerve block, the time taken to deflate the tourniquet because of a tourniquet pain, the time passed until feeling a postoperative pain after the operation, etc. We also studied the complications and satisfaction of the anesthesia. Results: It took 6.2 (3 to 12) minutes for the nerve block, 46.1 (28 to 75) minutes to start the operation, 52.5 (22 to 78) minutes until feeling a tourniquet pain and 11.5 (7.5 to 19) hours until starting to feeing a postoperative pain. There was no complication by anesthesia and 21 people (95.5%) were satisfied with anesthesia by ultrasound-guided femorosciatic nerve block. Conclusion: Ultrasound-guided femorosciatic nerve block by orthopaedist in the fracture around ankle reduces anesthetic and nerve injury complication, and leads to high anesthetic success rate. Also it is considered as an effective method to alleviate postoperative pain.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1640-1646
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• 2005

An oriental medicinal drugs Jahageo (JHG, Hominis placenta) were examined to determine its effects on the responsiveness of central nervous system neurons after injury. We found that JHG was involved in neurite outgrowth of DRG sensory axons. JHG treatment also increased expression of axonal growth-associated protein GAP-43 in DRG sensory neurons after sciatic nerve injury and in the injured spinal cord. JHG treatment during the spinal cord injury increased induction levels of cell division cycle 2 (Cdc2) protein in DRG as well as in the spinal cord. Histochemical investigation showed that induced Cdc2 in the injured spinal cord was found in non-neuronal cells. These results suggest that JHG regulates activities of non-neuronal cells such as oligodendrocyte and astrocyte in responses to spinal cord injury and protects neuronal responsiveness after axonal damage.

• The Korean Journal of Pain
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• v.24 no.4
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• pp.185-190
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• 2011

Background: Spinal nerve ligation (SNL) injury in rats produces a pain syndrome that includes mechanical and thermal allodynia. Previous studies have indicated that proinflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) play an important role in peripheral mediation of neuropathic pain, and that altered dorsal root ganglion (DRG) function and degree of DRG neuronal apoptosis are associated with spinal nerve injury. The present study was conducted to evaluate the expression of TNF-${\alpha}$ and the extent of apoptosis in the dorsal root ganglion after SNL in rats. Methods: Sprague-Dawley rats were subjected to SNL of the left L5 and L6 spinal nerves distal to the DRG and proximal to the formation of the sciatic nerve. At postoperative day 8, TNF-${\alpha}$ protein levels in the L5.6 DRG were compared between SNL and naive groups using ELISA. In addition, we compared the percentage of neurons injured in the DRG using immunostaining for apoptosis and localization of activated caspase-3. Results: SNL injury produced significant mechanical and cold allodynia throughout the 7-day experimental period. TNF-${\alpha}$ protein levels were increased in the DRG in rats that had undergone SNL ($12.7{\pm}3.2$ pg/100 ${\mu}g$, P < 0.001) when compared with naive rats ($4.1{\pm}1.4$ pg/100 ${\mu}g$). The percentage of neurons or satellite cells co-localized with activated caspase-3 were also significantly higher in rats with SNL than in naive rats (P < 0.001, P < 0.05, respectively). Conclusions: SNL injury produces mechanical and cold allodynia, as well as TNF-${\alpha}$ elevation and apoptosis in the DRG.

• Physical Therapy Korea
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• v.7 no.3
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• pp.34-48
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• 2000

The purpose of this study was to determine the effects of mild-intensity exercise training on the denervated muscle atrophy in the sciatic nerve injured rat. Thirty-six male Sprague-Dawley rats (250~300 g) were randomly assigned into three groups; sham-denervated group (n=8), denervated group (n=8), and denervated-exercised group (n=20). Exercise consisted of treadmill running at 20 m/min speed with 0% grade for 30 min/day. The animals were decapitated at the second and sixth weeks postcrush. Soleus and medial gastrocnemius were immediately excised to be weighed. Type I and II fibers of the muscles were differentiated by m-ATPase (pH 9.4) stain, and fiber diameters were evaluated. The results were as follows: 1) The weight of the soleus and medial gastrocnemius muscles showed a tendency to increase in both the denervation-exercised groups compared to the denervated group. 2) In the 2-week denervation-exercised group, type II fiber diameter of soleus and type I fiber diameter of medial gastrocnemius were increased significantly compared to the denervated control group. 3) In the 6-week denervated-exercised group, type I fiber diameter of soleus and type II fiber diameter of medial gastrocnemius were hypertrophied significantly compared to sham-denervated group. The results of this study suggested that treadmill exercise partially prevented denervation atrophy in the soleus and medial gastrocnemius of the rat.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.35-46
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• 2021

Background: The present investigation explored the therapeutic actions of oleuropein along with the possible signaling pathway involved in attenuating neuropathic pain in chronic constriction injury (CCI) and vincristine-induced neuropathic pain in male rats. Methods: Four loose ligatures were placed around the sciatic nerve to induce CCI, and vincristine (50 ㎍/kg) was injected for 10 days to develop neuropathic pain. The development of cold allodynia, mechanical allodynia, and mechanical hyperalgesia was assessed using different pain-related behavioral tests. The levels of H2S, cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS), orexin, and nuclear factor erythroid-2-related factor 2 (Nrf2) were measured in the sciatic nerve. Results: Treatment with oleuropein for 14 days led to significant amelioration of behavioral manifestations of neuropathic pain in two pain models. Moreover, oleuropein restored both CCI and vincristine-induced decreases in H2S, CSE, CBS, orexin, and Nrf2 levels. Co-administration of suvorexant, an orexin receptor antagonist, significantly counteracted the pain-attenuating actions of oleuropein and Nrf2 levels without modulating H2S, CSE and CBS. Conclusions: Oleuropein has therapeutic potential to attenuate the pain manifestations in CCI and vincristine-induced neuropathic pain, possibly by restoring the CSE, CBS, and H2S, which may subsequently increase the expression of orexin and Nrf2 to ameliorate behavioral manifestations of pain.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.5
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• pp.237-243
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• 2004

Glial cells are activated in neuropathy and play a key role in hyperalgesia and allodynia. This study was performed to determine whether minocycline could attenuate heat hyperalgesia and mechanical allodynia, and how glial cell activation and nuclear factor kappa B (NF-kappaB) were regulated by minocycline in a model of chronic constriction of sciatic nerve (CCl). When minocycline (50 mg/kg, oral) was daily administered from 1 day before to 9 days after ligation, heat hyperalgesia and mechanical allodynia were attenuated. Furthermore, when minocycline treatment was initiated 1 or 3 days after ligation, attenuation of the hypersensitive behavior was still robust. However, the effect of attenuation was less when minocycline was started from day 5. In order to elucidate the mechanism of pain attenuation by minocycline, we examined the changes of glia and NF-kappaB, and found that attenuated hyperalgesia and allodynia by minocycline was accompanied by reduced microglial activation. Furthermore, the number of NF-kappaB immunoreactive cells increased after CCI treatment and this increase was attenuated by minocycline. We also observed translocation of NF-kappaB into the nuclei of activated glial cells. These results suggest that minocycline inhibits activation of glial cells and NF-kappaB, thereby attenuating the development of behavioral hypersensitivity to stimuli.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.378-385
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• 1998

Chloramphenicol주사에 의한 좌골신경손상을 유발한 후 Prednisolone을 이용한 약물처치군, 전침군 및 전침과 약물을 병용한 군에서 각각 회복속도를 비교하였다. 정상보행 횟수, pinching을 통한 감각신경의 통감반응,그리고 병리조직소견 등을 죠사한 결과를 요약 하면 다음과 같다. Enrofloxacin, cefazolin, cephalexin, penicillin 등의 좌골신경주위 주사게 서는 신경마비가 관찰되지 않았으나 chloramphenicol을 주사할 경우에는 좌골신경손상으로 인한 편측성 후지마비가 유발되어 knuckling 반응을 보였다. Chloramphenicol을 투여한후 좌골신경손상에 대한 각 처치에서 정상보행 횟수는 8-12주까지는 침술처치군이 약간 중가하 였으나, 처리군간 유의성은 관찰되지 않았다. 실험기간동안 chloramphenicol 에 의한 신경손 상에 대한 각 처치군별 병리조직 소견은 호전양상이 관찰되지 아니하였다.

• Annals of Clinical Neurophysiology
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• v.22 no.1
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• pp.19-23
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• 2020

Background: Peripheral nerve injury rarely occurs in patients with rhabdomyolysis. Based on our experience and previous reports, we consider prolonged immobilization a risk factor for the development of peripheral neuropathy in rhabdomyolysis patients. Methods: This study analyzed 28 patients with rhabdomyolysis due to prolonged immobilization. We analyzed their demographic and laboratory data, clinical and imaging findings, and outcomes, and compared these factors between patients with and without neuropathy. Results: Seven of the 28 patients had peripheral neuropathy, including sciatic neuropathy or lumbosacral plexopathy. Compared to those without neuropathy, the patients with neuropathy were younger (p = 0.02), had higher peak creatine kinase (CK) levels (p = 0.02), had higher muscle uptake in bone scans (p = 0.03), and more frequently exhibited abnormal muscle findings in computed tomography (CT) (p = 0.004). Conclusions: Patients with prolonged immobilization-induced rhabdomyolysis and neuropathy had higher CK levels, increased uptake on bone scans, and more-frequent abnormal muscles on CT than those without neuropathy. These findings indicate that peripheral neuropathy is more likely to develop in patients with severe muscle injury.