• Journal of Korean Neurosurgical Society
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• 제54권1호
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• pp.8-13
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• 2013

Objective : This study investigates the effect of valproic acid (VPA) on expression of neural stem/progenitor cells (NSPCs) in a rat spinal cord injury (SCI) model. Methods : Adult male rats (n=24) were randomly and blindly allocated into three groups. Laminectomy at T9 was performed in all three groups. In group 1 (sham), only laminectomy was performed. In group 2 (SCI-VPA), the animals received a dose of 200 mg/kg of VPA. In group 3 (SCI-saline), animals received 1.0 mL of the saline vehicle solution. A modified aneurysm clip with a closing force of 30 grams was applied extradurally around the spinal cord at T9, and then rapidly released with cord compression persisting for 2 minutes. The rats were sacrificed and the spinal cord were collected one week after SCI. Immunohistochemistry (IHC) and western blotting sample were obtained from 5 mm rostral region to the lesion and prepared. We analyzed the nestin immunoreactivity from the white matter of ventral cord and the ependyma of central canal. Nestin and SOX2 were used for markers for NSPCs and analyzed by IHC and western blotting, respectively. Results : Nestin and SOX2 were expressed significantly in the SCI groups but not in the sham group. Comparing SCI groups, nestin and SOX2 expression were much stronger in SCI-VPA group than in SCI-saline group. Conclusion : Nestin and SOX2 as markers for NSPCs showed increased expression in SCI-VPA group in comparison with SCI-saline group. This result suggests VPA increases expression of spinal NSPCs in SCI.

• Applied Microscopy
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• 제27권2호
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• pp.177-187
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• 1997

Hydrocephalus is induced experimentally in prenatal and suckling animals following an injection of 6-aminonicotinamide (6-AN). The most remarkable characteristic of these animals is aqueduct stenosis caused by swellings of the ependymal cells and subependymal cells in the periaqueductal gray matter and the central canal of the spinal cord. The present study was undertaken to investigate the morphological changes of the ependymal cells in the central canal of the spinal cord of 3.5 months old hamster after treatment with 6-AN. Intraperitoneal administrations of 6-AN (10 mg/kg body weight) every two days gave rise to partial central canal stenosis of the spinal cord after 27-29 days (13-l4th injection), but cilia and microvilli were located in the strictural area of the con#rat canal. The vacuolations in the ependymal cells were not observed and degenerating changes of intracellular organelles of the ependymal cells did not occur, so that the ependymal cells lining the central canal of the hamster spinal cord were not affected by 6-AN. But the present study demonstrate that 6-AN causes to create numerous vacuoles in the subependymal area of the central canal. Although the vacuoles were well developed in the neuroglial cells and the neuropils of the subependymal area, the neurons were not affected by 6-AN. These results strongly suggests that partial central canal stenosis occurred by 6-AN was due to vacuolations and swellings of the neuroglial cells and nueropils in the subependymal area.

• The Journal of Korean Physical Therapy
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• 제16권2호
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• pp.169-180
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• 2004

The aim of this study was to investigate the effect of TENS on muscle pain induced by carrageenan. Muscle pain was induced in male Sprague-Dowley rats by intra-muscular injection of gastrocnemius with $3\%$ carrageenan. nNOS was measured to assess the effect of TENS on muscle pain induced by Carrageenan. The lumbar enlargement of the spinal cord was removed in different groups of animals 24 h after induction of muscle pain. The level of nNOS mRNA was measured in the lumbar section of the spinal cord using RT-PCT. The expression of nNOS was analyzed in the dorsal horn of the lumbar spinal cord by immunohistochemistry. TENS decreased nNOS immunoreactivity in the dorsal horn of the lumbar spinal cord when compared with controls(p<.05). In RT-PCR, TENS decreased nNOS mRNA level of lumbar spinal cord when compared with controls(p<.05). These results suggested that application of TENS attributed to decrease muscle pain.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.131-146
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• 2002

In the last years, it has become possible to regain some locomotor activity in patients with incomplete spinal cord injury (SCI) through intense training on a treadmill. The ideas behind this approach owe much to insights derived from animal studies. Many studies showed that cats with complete spinal cord transection(spinalized animals) can recover locomotor function. These observations were at the basis of the concept of the central pattern generator located at spinal level. The neural system responsible for the locomotor restoration in both cats and humans is thought to be located at spinal level and is referred to as the central pattern generator(CPG). The evidence for such a spinal CPG in human is emphasis on some recent developments which support the view that there is a human spinal CPG for locomotion. An important element in afferent inputs for both spinal injured cats and humans is the provision of adequate sensory input related locomotor, which can possibly activate and/or regulate the spinal locomotor circuitry This review article deals with the afferent control of the central pattern generator. Furthermore, the application of adequate afferent inputs related locomotor for stroke patients will be able to facilitate locomotion ability, which is automatic, cyclic, rhythmic. These insights can possibly contribute to a better therapeutic approach for the rehabilitation of gait in patients with stroke.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.303-303
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• 1994

ICV infusion of morphine (MOR) produces strong analgesia in man and animals. The analgesic effect is thought to be mediated by the centrifugal inhibtory control, But neural mechanisms of the analgesic effect of ICV morphine are not well understood. For example, in the previous studies, ICV morphine does not inhibit nociceptive transmission in the spinal cord. On the contrary, ICV MOR often excites activity of dorsal horn neuron in the spinal cord. In the present study, we found that ICV MOR had dust actions on activity of dorsal horn neuron that it produced both inhibition and excitation of dorsal horn neurons. Since MOR exerts i Is action via three different types of opioid receptors, we further sought to investigate if there are differential effects of opioid receptor agonists on dorsal horn neurons when administered ICV.

• The Korean Journal of Pain
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• 제27권3호
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• pp.200-209
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• 2014

Background: Spinal opioid administration is an excellent option to separate the desirable analgesic effects of opioids from their expected dose-limiting side effects to improve postoperative analgesia. Therefore, physicians must better identify either specific opioids or adequate doses and routes of administration that result in a mainly spinal site of action rather than a cerebral analgesic one. Methods: The purpose of this topical review is to describe current available clinical evidence to determine what opioids reach high enough concentrations to produce spinally selective analgesia when given by epidural or intrathecal routes and also to make recommendations regarding their rational and safety use for the best management of postoperative pain. To this end, a search of Medline/Embase was conducted to identify all articles published up to December 2013 on this topic. Results: Recent advances in spinal opioid bioavailability, based on both animals and humans trials support the theory that spinal opioid bioavailability is inversely proportional to the drug lipid solubility, which is higher in hydrophilic opioids like morphine, diamorphine and hydromorphone than lipophilic ones like alfentanil, fentanyl and sufentanil. Conclusions: Results obtained from meta-analyses of RTCs is considered to be the 'highest' level and support their use. However, it's a fact that meta-analyses based on studies about treatment of postoperative pain should explore clinical surgery heterogeneity to improve patient's outcome. This observation forces physicians to use of a specific procedure surgical-based practical guideline. A vigilance protocol is also needed to achieve a good postoperative analgesia in terms of efficacy and security.

• Korean Journal of Acupuncture
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• 제36권3호
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• pp.162-170
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• 2019

Objectives : Increasing evidence suggests that parasympathetic vagus nerve activity plays a role in modulating acupuncture-induced anti-inflammatory reaction, but the function of sympathetic nerve is not known. Here, we investigated whether splanchnic sympathetic nerve activity was involved in the regulation of splenic expression of $TNF-{\alpha}$ mRNA by electroacupuncture (EA) in LPS-injected animals. Methods : DiI was injected into the stomach or celiac ganglion (CG) for retrograde labeling of the target tissues. EA was given at ST36 and the electrical stimulation on the sciatic nerve in LPS-injected mice. c-Fos signals in the tissues were analyzed by immunofluorescence staining, and $TNF-{\alpha}$ mRNA was analyzed by real-time PCR. Results : Application of EA at ST36 or electrical stimulation on the sciatic nerve induced c-Fos expression in neurons of the spinal cord and celiac ganglion (CG). Then, the vagotomy reduced c-Fos levels in CG neurons but not in the spinal cord in animals given EA. Expression of $TNF-{\alpha}$ mRNA which was induced in the spleen after LPS was significantly inhibited by EA, then the vagotomy elevated $TNF-{\alpha}$ mRNA level similar to that in LPS-injected animals. Splanchnectomy in animals given LPS and EA also increased $TNF-{\alpha}$ mRNA though it was less effective than vagotomy. Conclusions : Our data suggest that EA delivered to the spleen via the splanchnic sympathetic nerve may be involved in attenuating splenic inflammatory responses in LPS-injected animals.

• The Korean Journal of Pain
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• 제32권1호
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• pp.12-21
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• 2019

Spinal cord contusion injury is one of the most serious nervous system disorders, characterized by high morbidity and disability. To mimic spinal cord contusion in humans, various animal models of spinal contusion injury have been developed. These models have been developed in rats, mice, and monkeys. However, most of these models are developed using rats. Two types of animal models, i.e. bilateral contusion injury and unilateral contusion injury models, are developed using either a weight drop method or impactor method. In the weight drop method, a specific weight or a rod, having a specific weight and diameter, is dropped from a specific height on to the exposed spinal cord. Low intensity injury is produced by dropping a 5 g weight from a height of 8 cm, moderate injury by dropping 10 g weight from a height of 12.5-25 mm, and high intensity injury by dropping a 25 g weight from a height of 50 mm. In the impactor method, injury is produced through an impactor by delivering a specific force to the exposed spinal cord area. Mild injury is produced by delivering $100{\pm}5kdyn$ of force, moderate injury by delivering $200{\pm}10kdyn$ of force, and severe injury by delivering $300{\pm}10kdyn$ of force. The contusion injury produces a significant development of locomotor dysfunction, which is generally evident from the $0-14^{th}$ day of surgery and is at its peak after the $28-56^{th}$ day. The present review discusses different animal models of spinal contusion injury.

• 한국임상수의학회지
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• 제34권5호
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• pp.347-352
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• 2017

Pain, an adaptive but unpleasant sensation, is the most common symptom of numerous diseases in humans and animals. Although animal patients express this symptom frequently, a lack of communication abilities hinders its recognition by veterinary physicians, thereby leading to unsatisfactory management of the symptom. On the other hand, pain itself has its own neurological mechanisms, regardless of the disease that causes it. Thus, a physician may need to know the mechanisms underlying pain development in order to properly manage the symptom in a particular disease. In this review, we attempt to provide a brief introduction to the anatomical, physiological, and neurological basis of pain transmission and sensation. Although most knowledge about these mechanisms comes from studies in humans and laboratory animals, it is generally applicable to pet, farm, or zoo animals. In addition, we summarize pain behavior in several pet, farm, and laboratory animals for its proper identification. This information will help to identify and manage pain, and thus improve welfare, in animals.

• The Korean Journal of Pain
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• 제23권2호
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• pp.109-115
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• 2010

Background: The pathophysiological and neurochemical changes following spinal injury are not yet elucidated. This study was designed to evaluate the morphological changes of the dorsal horn of the spinal cord and profiles of pain behaviors following intraspinal injection of NMDA in rats. Methods: Rats were randomized into three groups: a sham-operated control group and groups where the rats received 10 mM or 100 mM N-methyl-D-aspatate (NMDA) injected into their spinal dorsal horn. Following injection, hypersensitivity to cold and mechanical stimuli and excessive grooming behaviors were assessed serially for four weeks. Morphological changes of the spinal cord were evaluated four weeks after intraspinal injection. Results: Few animals in the NMDA groups developed hypersensitivity to cold and mechanical stimuli. The number of groomers and the severity of excessive grooming were significantly higher in the 100 mM NMDA group than those values of the control and 10 mM NMDA groups. The size of the neck region (lamina III-IV) was significantly smaller in the 100 mM NMDA group than in the control and 10 mM NMDA groups. Conclusions: In conclusion, intraspinal injection of NMDA in rats leads to the pathological sequela in the spinal cord and to excessive grooming behavior. These results support the use of NMDA and excessive grooming behavior after excitotoxic SCI as a model to study chronic pain after SCI.