• Journal of Korean Neurosurgical Society
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• 제58권1호
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• pp.22-29
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• 2015

Objective : Perinatal hypoxic-ischemic encephalopathy (HIE) and prolonged febrile seizures (pFS) are common neurologic problems that occur during childhood. However, there is insufficient evidence from experimental studies to conclude that pFS directly induces hippocampal injury. We studied cognitive function and histological changes in a rat model and investigated which among pFS, HIE, or a dual pathologic effect is most detrimental to the health of children. Methods : A rat model of HIE at postnatal day (PD) 7 and a pFS model at PD10 were used. Behavioral and cognitive functions were investigated by means of weekly open field tests from postnatal week (PW) 3 to PW7, and by daily testing with the Morris water maze test at PW8. Pathological changes in the hippocampus were observed in the control, pFS, HIE, and HIE+pFS groups at PW9. Results : The HIE priming group showed a seizure-prone state. The Morris water maze test revealed a decline in cognitive function in the HIE and HIE+pFS groups compared with the pFS and control groups. Additionally, the HIE and HIE+pFS groups showed significant hippocampal neuronal damage, astrogliosis, and volume loss, after maturation. The pFS alone induced minimal hippocampal neuronal damage without astrogliosis or volume loss. Conclusion : Our findings suggest that pFS alone causes no considerable memory or behavioral impairment, or cellular change. In contrast, HIE results in lasting memory impairment and neuronal damage, gliosis, and tissue loss. These findings may contribute to the understanding of the developing brain concerning conditions caused by HIE or pFS.

• 한국한의학연구원논문집
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• 제12권3호통권18호
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• pp.49-58
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• 2006

Although the usage of acupuncture for pain has increased in recent years, the mechanisms of acupuncture analgesia (AA) remain unclear. The lack of suitable experimental animal models for persistent pain, which show clear AA, has been the major stumbling block in the investigation of the physiological mechanisms of AA. In the present study, we test AA in two knee arthritis models induced by injection of CFA or carrageenan as persistent pain models. After induction of arthritis, the rat subsequently showed a reduced stepping force of the affected limb for the next several days. Electroacupuncture (EA) was applied to an acupuncture point each on the contralateral forelimb for 30 minutes under gaseous anesthesia. After the termination of EA, behavioral tests measuring stepping force were periodically conducted during the next several hours. EA produced a significant improvement of stepping force of the foot lasting for at least 2 hours when applied to LR2 in CFA model, and applied to ST36 in carrageenan model, but both points did not produce any significant effects in each other model. Further experiments showed that intraperitoneal pretreatment of naltrexone, a non-selective opioid antagonist, did not reduced the EA-induced improvement of stepping force in both of two models. These data suggest that EA produce analgesic effect in knee arthritic pain and the analgesic effect is specific to the acupuncture point depending on painful conditions.

• The Korean Journal of Pain
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• 제31권1호
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• pp.10-15
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• 2018

Background: To identify a new strategy for postoperative pain management, we investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and also assessed its effects on the activities of the primary afferent fibers at the dorsal horn. Methods: In experiment 1, 45 rats were assigned to Control, Allo small-dose (0.16 mg/kg), and Allo large-dose (1.6 mg/kg) groups (n = 15 in each). The weight bearing and mechanical withdrawal thresholds of the hind limb were measured before and at 2, 24, 48, and 168 h after Brennan's surgery. In experiment 2, 16 rats were assigned to Control and Allo (0.16 mg/kg) groups (n = 8 in each). The degree of spontaneous pain was measured using the grimace scale after the surgery. Activities of the primary afferent fibers in the spinal cord (L6) were evaluated using immunohistochemical staining. Results: In experiment 1, the withdrawal threshold of the Allo small-dose group was significantly higher than that of the Control group at 2 h after surgery. Intergroup differences in weight bearing were not significant. In experiment 2, intergroup differences in the grimace scale scores were not significant. Substance P release in the Allo (0.16 mg/kg) group was significantly lower than that in the Control group. Conclusions: Systemic administration of Allo inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allo was proposed as a candidate for postoperative pain management.

• Clinical and Experimental Pediatrics
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• 제56권3호
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• pp.116-124
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• 2013

Purpose: Tumor necrosis factor (TNF)-${\alpha}$ is thought to contribute to pulmonary hypertension. We aimed to investigate the effect of infliximab (TNF-${\alpha}$ antagonist) treatment on pathologic findings and gene expression in a monocrotaline-induced pulmonary hypertension rat model. Methods: Six-week-old male Sprague-Dawley rats were allocated to 3 groups: control (C), single subcutaneous injection of normal saline (0.1 mL/kg); monocrotaline (M), single subcutaneous injection of monocrotaline (60 mg/kg); and monocrotaline + infliximab (M+I), single subcutaneous injection of monocrotaline plus single subcutaneous injection of infliximab (5 mg/kg). The rats were sacrificed after 1, 5, 7, 14, or 28 days. We examined changes in pathology and gene expression levels of TNF-${\alpha}$, endothelin-1 (ET-1), endothelin receptor A (ERA), endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP) 2, and tissue inhibitor of matrix metalloproteinase (TIMP). Results: The increase in medial wall thickness of the pulmonary arteriole in the M+I group was significantly lower than that in the M group on day 7 after infliximab treatment (P<0.05). The number of intraacinar muscular arteries in the M+I group was lower than that in the M group on days 14 and 28 (P<0.05). Expression levels of TNF-${\alpha}$, ET-1, ERA, and MMP2 were significantly lower in the M+I group than in the M group on day 5, whereas eNOS and TIMP expressions were late in the M group (day 28). Conclusion: Infliximab administration induced early changes in pathological findings and expression levels of TNF-${\alpha}$, and MMP2 in a monocrotaline-induced pulmonary hypertension rat model.

• Journal of Korean Neurosurgical Society
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• 제51권6호
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• pp.323-327
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• 2012

Objective : The purpose of this study was to verify the appropriateness of ovariectomized rats as the osteoporosis animal model. Methods : Twelve female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy [the ovariectomy (OVX) group]. Eight weeks after operations, serum biochemical markers of bone turnover were analyzed; osteocalcin and alkaline phosphatase, which are sensitive biochemical markers of bone formation, and C-terminal telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption. Bone histomorphometric parameters and microarchitectural properties of 4th lumbar vertebrae were determined by micro-computed tomographic (CT) scan. Results : The OVX group showed on average 75.4% higher osteocalcin and 72.5% higher CTX levels than the sham group, indicating increased bone turnover. Micro-CT analysis showed significantly lower bone mineral density (BMD) (p=0.005) and cortical BMD (p=0.021) in the OVX group. Furthermore, the OVX group was found to have a significantly lower trabecular bone volume fraction (p=0.002). Conclusion : Our results showed that bone turnover was significantly increased and bone mass was significantly decreased 8 weeks after ovariectomy in rats. Thus, we propose that the ovariectomized rat model be considered a reproducible and reliable model of osteoporosis.

• Journal of Korean Neurosurgical Society
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• 제43권1호
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• pp.26-30
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• 2008

Objective : The authors developed a stereotactic device for irradiation of small animals with Leksell Gamma Knife Model C. Development and verification procedures were described in this article. Methods : The device was designed to satisfy three requirements. The mechanical accuracy in positioning was to be managed within 0.5 mm. The strength of the device and structure were to be compromised to provide enough strength to hold a small animal during irradiation and to interfere the gamma ray beam as little as possible. The device was to be used in combination with the Leksell G-$frame^{(R)}$ and $KOPF^{(R)}$ rat adaptor. The irradiation point was determined by separate imaging sequences such as plain X-ray images. Results : The absolute dose rate with the device in a Leksell Gamma Knife was 3.7% less than the value calculated from Leksell Gamma $Plan^{(R)}$. The dose distributions measured with $GAFCHROMIC^{(R)}$ MD-55 film corresponded to those of Leksell Gamma $Plan^{(R)}$ within acceptable range. The device was used in a series of rat experiments with a 4 mm helmet of Leksell Gamma Knife. Conclusion : A stereotactic device for irradiation of small animals with Leksell Gamma Knife Model C has been developed so that it fulfilled above requirements. Absorbed dose and dose distribution at the center of a Gamma Knife helmet are in acceptable ranges. The device provides enough accuracy for stereotactic irradiation with acceptable practicality.

• 한국지능시스템학회논문지
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• 제14권5호
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• pp.545-550
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• 2004

생태학, 환경공학, 임상진단 등 생물학 분야에서 미생물의 다양성 연구의 중요성이 대두되고 그 연구가 점증하고 있다. 특히 16S rRNA를 분자지표로한 DNA 염기서열 분석방법이 널리 사용되고 있다. 본 논문에서는 16S rRNA의 염기서열 분석과정을 각 단계별로 자동화하고, 생물학자들의 결과 판단이나 사용상의 편의를 도모하기 위하여 웹기반의 미생물 다양성 분석 어플리케이션을 개발하였다. 이를 위하여 단계별 자동화 및 인터페이스 개발에 적합한 폴더-프로세스-필터 모델을 고안하고 적용하였다. 제공되는 생물정보분석도구는 서열입력, 서열방향교정, 다중서열정렬 및 가시화, 서열동정 등의 분석이 있으며, 각 결과는 계통분류도구와 호환 가능하도록 하였다. 또한 신생아의 장내 세균총에 대한 분석을 수행하여 개발된 도구의 유용성을 확인하였다. 개발된 웹 어플리케이션은 리눅스 시스템 상에서 Perl 과 CGI를 이용하였으며, http://home.pusan.ac.kr/～genome/tools/rat.htm으로 접속하여 사용할 수 있다.

• International Journal of Oral Biology
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• 제34권3호
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• pp.157-164
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• 2009

We recently described a novel animal model of trigeminal neuropathic pain following compression of the trigeminal ganglion (Ahn et al., 2009). In our present study, we adapted this model using male Sprague-Dawley rats weighing between 250-260 g and then analyzed the behavioral responses of these animals following modified chronic compression of the trigeminal ganglion. Under anesthesia, the rats were mounted onto a stereotaxic frame and a 4% agar solution ($10{\mu}L$) was injected in each case on the dorsal surface of the trigeminal ganglion to achieve compression without causing injury. In the control group, the rats received a sham operation without agar injection. Air-puff, acetone, and heat tests were performed at 3 days before and at 3, 7, 10, 14, 17, 21, 24, 30, 40, 55, and 70 days after surgery. Compression of the trigeminal ganglion produced nociceptive behavior in the trigeminal territory. Mechanical allodynia was established within 3 days and recovered to preoperative levels at approximately 60 days following compression. Mechanical hyperalgesia was also observed at 7 days after compression and persisted until the postoperative day 40. Cold hypersensitivity was established within 3 days after compression and lasted beyond postoperative day 55. In contrast, compression of the trigeminal ganglion did not produce any significant thermal hypersensitivity when compared with the sham operated group. These findings suggest that compression of the trigeminal ganglion without any injury produces prolonged nociceptive behavior and that our rat model is a useful system for further analysis of trigeminal neuralgia.

• 동의신경정신과학회지
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• 제12궈1호
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• pp.123-135
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• 2001

Objective: This study was designed to assess antidepressant effects of Quibitang on an Animal Model of Depression induced by Chronic Mild Stress. Method: The consumption of 1% sucrose solution and active avoidance learning test were used to evaluate antidepressant effect of Quibitang. The consumption of 1% sucrose solution was measured every week for 8 weeks, and active avoidance learning test was executed after 4 weeks treatment of saline or Quibitang. Result: 1. The consumption of 1% sucrose solution was significantly reversed in test group (Quibitang-treated group) at 5th, 7th, 8th weeks, but there was no significant change in control group. 2. Chronic Mild Stress was found to suppress the increase of body weight at 5th, 6th, 7th, 8th weeks. Treatment of Quibitang did not enhanced the body weigt, but it enhanced the consumption of sucrose solution. 3. In order to measure the learning ability of rat which drived to be depressed, we executed active avoidance test. The result revealed that depressed rat showed impaired acquisition than control group, and the treatment of Quibitang restored the learning activity. Conclusion: These results suggest that Quibitang may have antidepressant effects on depression induced by chronic mild stress.

• Korean Journal of Acupuncture
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• 제36권4호
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• pp.264-273
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• 2019

Objectives : Microglia play a crucial role in electroacupuncture (EA) analgesia on neuropathic pain. The role of chemokines in producing analgesic effects of EA, however, is largely unknown. In the present study, we investigated the role of chemokines in producing analgesic effects of EA in the neuropathic pain model. Methods : Sprague-Dawley rats were randomly assigned into three groups (anesthetized group (ANE), non-acupoint EA group (NAP), and ST36 - GB34 EA group (ACU)). Neuropathic pain was induced by tight ligation of L5 spinal nerve. Mechanical and thermal hypersensitivity of hind paw was tested. Western blot tests and immunofluorescence assay for C-C motif chemokine ligand 2 (CCL2) levels and microglia activation were performed on spinal cord L5/6. EA was treated once daily from the 3rd day after surgery for 5 days. Results : EA treatments applied to ST36 and GB34 significantly reduced both mechanical and thermal hypersensitivity after two and three times of treatment, respectively. While CCL2 expression significantly increased in neuropathic rats, it was significantly reduced in the ACU. In addition, co-localization of CCL2 and activated microglia significantly decreased in the ACU compared to those of ANE and NAP in the spinal cord L5/L6 dorsal horn. Conclusions : The present results suggest that EA applied to ST36 and GB34 modulates the reduction of CCL2 release from the injured neurons and consequently decreases microglia activation in the spinal cord. Regulation of chemokine induced spinal activation of microglia plays a key role in analgesic effects of EA in the rat model of neuropathic pain.