• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1609-1614
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• 2013

Objective: To evaluate the effect of intravenous contrast on dose calculation in radiation treatment planning for oesophageal cancer. Methods: A total of 22 intravein-contrasted patients with oesophageal cancer were included. The Hounsfield unit (HU) value of the enhanced blood stream in thoracic great vessels and heart was overridden with 45 HU to simulate the non-contrast CT image, and 145 HU, 245 HU, 345 HU, and 445 HU to model the different contrast-enhanced scenarios. 1000 HU and -1000 HU were used to evaluate two non-physiologic extreme scenarios. Variation in dose distribution of the different scenarios was calculated to quantify the effect of contrast enhancement. Results: In the contrast-enhanced scenarios, the mean variation in dose for planning target volume (PTV) was less than 1.0%, and those for the total lung and spinal cord were less than 0.5%. When the HU value of the blood stream exceeded 245 the average variation exceeded 1.0% for the heart V40. In the non-physiologic extreme scenarios, the dose variation of PTV was less than 1.0%, while the dose calculations of the organs at risk were greater than 2.0%. Conclusions: The use of contrast agent does not significantly influence dose calculation of PTV, lung and spinal cord. However, it does have influence on dose accuracy for heart.

• The Korean Journal of Pain
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• v.24 no.3
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• pp.154-157
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• 2011

Background: Postherpetic neuralgia (PHN) is usually managed pharmacologically. It is not uncommon for patients with chronic kidney disease (CKD) to suffer from PHN. It is difficult to prescribe a sufficient dose of anticonvulsants for intractable pain because of the decreased glomerular filtration rate. If the neural blockade and pulsed radiofrequency ablation provide only short-term amelioration of pain, spinal cord stimulation (SCS) with a low level of evidence may be used only as a last resort. This study was done to evaluate the efficacy of spinal cord stimulation in the treatment of PHN in patients with CKD. Methods: PHN patients with CKD who needed hemo-dialysis who received insufficient relief of pain over a VAS of 8 regardless of the neuropathic medications were eligible for SCS trial. The follow-up period was at least 2 years after permanent implantation. Results: Eleven patients received percutaneous SCS test trial from Jan 2003 to Dec 2007. Four patients had successfully received a permanent SCS implant with their pain being tolerable at a VAS score of less than 3 along with small doses of neuropathic medications. Conclusions: SCS was helpful in managing tolerable pain levels in some PHN patients with CKD along with tolerable neuropathic medications for over 2 years.

• Korean Journal of Veterinary Service
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• v.14 no.1
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• pp.71-77
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• 1991

Parathion is widely used in agriculture, but it is highly toxic and now clear that parathion behaves like a cholinergic drug by inhibiting the enzyme cholinesterase. In order to know acute toxicity and the changes of cholinesterase activity according to time lapsed in Sprague-Dawley rats injected single with half dose to LD$_{50}$ of parathion, cholinesterase activities in serum, spinal cord, whole brain and median lethal dose between sex difference were investigated. The results obtained were summerized as follows ; 1. 4LD_{50}$ values of parathion given intraperitoneally to male and female rats were 10.5mg / kg(95% confidence limits, 6.6-16.8mg/ kg) and 3.3mg/ kg(95% confidence limits, 1.9-5.6mg/ kg). 2. The inhibition rate of cholinesterase activities in serum of parathion-injected rats according to time lapsed were peakly decreased to 35.4%(male) and 32.4%(female) after 1 hour in comparison to control group, but cholinesterase activities were completely recovered after 48 hours. 3. The inhibition rate of cholinesterase activities in spinal cord of parathion-injected rats according to time lapsed were peakly decreased to 31.1% (male) and 36.3% (female) after 30 minutes in comparison to control group, but cholinesterase activities were completely recovered after 48 hours. 4. The inhibition rate of cholinesterase activities in whole brain of parathion -injected rats according to time lapsed were peakly decreased to 32.2%(male) and 42.6%(female) after 1 hour in comparison to control group, but cholinesterase activities were completely recovered after 48 hours.s.

• Korean Journal of Veterinary Service
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• v.15 no.1
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• pp.58-66
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• 1992

The insecticide p-nitropheny diethyl thiophospate is alse known by the symbol E.605 and a legion of trade names including “parathion”. The insecticide is widely used in agriculture, but it is highly toxic and now clear that parathion behaves like a cholinergic drug by inhibiting the enzyme cholinesterase. In order to know acute toxicity and the changes of glucose concentrations and activity according to time lapsed in female mice given orally single with the half dose to $LD_{50}$ of parathion, glucose contents and cholinesterase activities in serum as well as cholinesterase activities in whole brain and spinal cord were investigated, otherwise median lethal dose ($LD_{50}$) of parathion given orally against female mice was determined. The results obtained were summerized as follows ; 1. $LD_{50}$ value of parathion given orally to female mice was 7.1mg/kg(95% confidence limits, 3.8-13.1mg/kg) 2. The inhibition rate of cholinesterase activities in serum of parathion-administrated mice according to time lapsed were peakly decreased to 61% after 30 minutes in comparison to control group, but activities were completely recovered after 48 hours. 3. The inhibition rate of cholinesterase activities in whole brain of parathion-administrated mice according to time lapsed were peakly decreased to 49% after 2 hours in completely recovered after 24 hours. 4. The inhibition rate of cholinesterase activities in spinal cord of parathion-administrated mice according to time lapsed were peakly decreased to 57% after 2 hours in comparison to control group, but activities were completely recovered after 48 hours. 5. The changes of glucose contents in serum of parathion-administrated mice according to time lapsed and in directly after death due to parathion poisoning were no significantly difference.

• Toxicological Research
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• v.13 no.4
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• pp.317-322
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• 1997

Acute delayed neurotoxicity of KH-502 [O.O-Diethyl O-(1-phenyyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester], an insecticide synthesized newly in Korea, was studied in White Leghorn hens. The doses were determined on the basis of preliminary $LD_{50}$ study. High, middle and low doses were determined to be 1123 mg/kg, 762 mg/kg and 518 mg/kg, respectively. The animals were pretreated with atropine (30 mg/kg) prior to administration of KH-502. The chemical was administrated at the first and 21st day of the study. As positive controls, animals were admlnistrated with triorthocresylphosphate (TOCP 1000 mg/kg and 500 mg/kg). Animals administrated with TOCP or KH-502 were sacrificed by perfusion-fixation at 21st and 42nd day of the study, respectively. The central and peripheral nerve tissues were routinely treated for microscopic observation. As results, eight, three, one, and one chickens died within 2 day after adminiatration with signs of cholinergic acute toxicity in high, middle low and TOCP dose-group (500 mg/kg), respectively. No abnormal clinical signs were observed in the survived chickens administrated with KH-502 in the duration of the study. The chickens in positive control groups showed ataxia and incoordination at the 14th day after administration of TOCP. From necropsy, macroscopic changes were not observed in all groups including positive control groups. Histopathologically, oxonal swelling with myelin loss, focal gliosis, distention around axonal space were observed in the spinal cords of the chickens administrated with TOCP 1000 mg/kg. The lesions were distinct in the dorsal and lateral funiculi of cervical spinal cord, in the lateral and ventral funiculi of thoracic spinal cord and in ventral funiculi of lumbosacral spinal cord. Axonal swelling and mlcrogliosis were infrequently observed in the chickens of other groups including negative control one. However, they were nonspecifically distributed in the spinal cords. In this study, we concluded that the new chemical, KH-502 did not have acute delayed neurotoxicity in White Leghorn hens.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.325-331
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• 2000

The present study was designed to assess the role of spinal adenosine $A_2$ receptor in the regulation of cardiovascular functions such as mean arterial pressure (MAP) and heart rate (HR) in male Sprague-Dawley rats. Rats (250~300 g) were anesthetized with urethane and paralyzed with d-tubocurarine and artificially ventilated. blood pressure and HR were continuously monitored via a femoral catheter connected to a pressure transducer and a polygraph. Drugs were administered intrathecally using injection cannula through guide cannula which was inserted inthrathecally at lower thoracic level through a puncture of an atlantooccipital mombrane. Intrathecal injection of an adenosine $A_2$ receptor agonist, 5'-(N-cyclopropyl)-carboxamaidoadenosine (CPCA; 1, 2 and 3 nmol, respectively), produced a dose-dependent decrease in MAP and HR. Pretreatment with $N^{G}$-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor or 10 nmol of MDL-12,330, an adenylate cyclase inhibitor blocked significantly the depressor and bradycardic effect of 2 nmol of CPCA. But, Pretreatment with 3 nmol of bicuculline, gamma-aminobutyric acid A (GAB $A_{A}$) receptor antagonist, or 50 nmol of 5-aminovaleric acid, GAB $A_{B}$ receptor antagonist did not inhibit the depressor and bradycardic effect of 2 nmol of CPCA. These results indicate that adenosine $A_2$ receptor in the spinal cord plays an inhibitory role in the regulation of cardiovascular function and that the depressor and bradycardic action of adonosine $A_2$ receptor are mediated via the synthesis of nitric oxide and the activation of adenylate cyclase in the spinal cord of rats.s.s.s.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.661-670
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• 1998

Dopamine has been generally known to exert antinociceptive action in behavioral pain test, such as tail flick and hot plate test, but there appears to be a great variance in the reports on the antinociceptive effect of dopamine depending on the dosage and route of drug administration and type of animal preparation. In the present study, the effects of dopamine on the responses of wide dynamic range (WDR) cells to mechanical, thermal and graded electrical stimuli were investigated, and the dopamine-induced changes in WDR cell responses were compared between animals with an intact spinal cord and the spinal animals. Spinal application of dopamine (1.3 & 2.6 mM) produced a dose-dependent inhibiton of WDR cell responses to afferent inputs, the pinch-induced or the C-fiber evoked responses being more strongly depressed than the brush-induced or the A-fiber evoked responses. The dopamine-induced inhibition was more pronounced in the spinal cat than in the cat with intact spinal cord. The responses of WDR cell to thermal stimulation were also strongly inhibited. Dopamine $D_2$ receptor antagonist, sulpiride, but not $D_1$ receptor antagonist, significantly blocked the inhibitory action of dopamine on the C-fiber and thermal responses of dorsal horn cells. These findings suggest that dopamine strongly suppresses the responses of WDR cells to afferent signals mainly through spinal dopamine $D_2$ receptors and that spinal dopaminergic processes are under the tonic inhibitory action of the descending supraspinal pathways.

• The Korean Journal of Pain
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• v.21 no.3
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• pp.179-186
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• 2008

Background: The adrenergic nervous system in the spinal cord contributes to the development of neuropathic pain after nerve injury. Brain derived neurotrophic factor may facilitate the sympathetic change in the spinal cord and influence the state of neuropathic pain. We probed the effect of chronic repetitive administration of systemic 4-methylcatechol, which is known to be a neurotrophic factor inducer, in a spinal nerve ligation model. Methods: We made the rat neuropathic pain model by the ligation of the L5 spinal nerve. Intraperitoneal 4-methylcatechol ($10{\mu}g/kg$) or the same volume of saline wasadministrated twice daily just after the operation for 7 days. The tactile allodynia was measured by using von Frey filaments and its change was followed up from 3 days after SNL. The lumbosacral enlargement of the spinal cord was taken out and the mRNA contents of the ${\alpha}_2-adrenoceptor$ subtypes were measured by real time polymerase chain reaction and this was then compared with the control groups. The antiallodynic effect of intrathecal clonidine (3, 10, $30{\mu}g$) was evaluated and compared in the 4-methylcatechol treated rats and the control rats. Results: The expression of the ${\alpha}_{2A}$ and ${\alpha}_{2C}$ adrenoceptor subtypes did not change after 4-methylcatechol treatment. Intrathecal clonidine showed an earlier and better effect at the highest dose ($30{\mu}g$ intrathecal), but not with any other doses. Conclusions: Chronic intraperitoneal administration of 4-methylcatechol may improve the effect of intrathecal clonidine, but we could not prove the increase of ${\alpha}_{2A}$ and ${\alpha}_{2C}$ adrenoceptors in the spinal cord of 4-methylcatechol treated rats.

• Journal of Korean Neurosurgical Society
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• v.59 no.5
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• pp.437-441
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• 2016

Objective : Recently, regenerative therapies have been used in clinical trials (heart, cartilage, skeletal). We don't make use of these treatments to spinal cord injury (SCI) patients yet, but regenerative therapies are rising interest in recent study about SCI. Neural precursor/stem cell (NPSC) proliferation is a significant event in functional recovery of the central nervous system (CNS). However, brain NPSCs and spinal cord NPSCs (SC-NPSCs) have many differences including gene expression and proliferation. The purpose of this study was to investigate the influence of neural growth factor (NGF) on the proliferation of SC-NPSCs. Methods : NPSCs ($2{\times}10^4$) were suspended in $100{\mu}L$ of neurobasal medium containing NGF-7S (Sigma-Aldrich) and cultured in a 96-well plate for 12 days. NPSC proliferation was analyzed five times for either concentration of NGF (0.02 and 2 ng/mL). Sixteen rats after SCI were randomly allocated into two groups. In group 1 (SCI-vehicle group, n=8), animals received 1.0 mL of the saline vehicle solution. In group 2 (SCI-NGF group, n=8), the animals received single doses of NGF (Sigma-Aldrich). A dose of 0.02 ng/mL of NGF or normal saline as a vehicle control was intra-thecally injected daily at 24 hour intervals for 7 days. For Immunohistochemistry analysis, rats were sacrificed after one week and the spinal cords were obtained. Results : The elevation of cell proliferation with 0.02 ng/mL NGF was significant (p<0.05) but was not significant for 2 ng/mL NGF. The optical density was increased in the NGF 0.02 ng/mL group compared to the control group and NGF 2 ng/mL groups. The density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group (p<0.05). High power microscopy revealed that the density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group. Conclusion : SC-NPSC proliferation is an important pathway in the functional recovery of SCI. NGF enhances SC-NPSC proliferation in vitro and in vivo. NGF may be a useful option for treatment of SCI patients pending further studies to verify the clinical applicability.

• Progress in Medical Physics
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• v.24 no.3
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• pp.145-153
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• 2013

Stereotactic body radiation therapy (SBRT) is increasingly used to treat spinal metastases. To achieve the highest steep dose gradients and conformal dose distributions of target tumors, intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques are essential to spine radiosurgery. The purpose of the study was to qualitatively compare IMRT and VMAT techniques with International Spine Radiosurgery Consortium (ISRC) contoured consensus guidelines for target volume definition. Planning target volume (PTV) was categorized as TB, $T_{BPT}$ and $T_{ST}$ depending on sectors involved; $T_B$ (vertebral body only), $T_{BPT}$ (vertebral body+pedicle+transverse process), and $T_{ST}$ (spinous process+transverse process). Three patients treated for spinal tumor in the cervical, thoracic, and lumbar region were selected. Eacg tumor was contoured by the definition from the ISRC guideline. Maximum spinal cord dose were 12.46 Gy, 12.17 Gy and 11.36 Gy for $T_B$, $T_{BPT}$ and $T_{ST}$ sites, and 11.81 Gy, 12.19 Gy and 11.99 Gy for the IMRT, RA1 and RA2 techniques, respectively. Average fall-off dose distance from 90% to 50% isodose line for $T_B$, $T_{BPT}$, and $T_{ST}$ sites were 3.5 mm, 3.3 mm and 3.9 mm and 3.7 mm, 3.7 mm and 3.3 mm for the IMRT, RA1 and RA2 techniques, respectively. For the most complicated target $T_{BPT}$ sites in the cervical, thoracic and lumbar regions, the conformity index of the IMRT, RA1 and RA2 is 0.621, 0.761 and 0.817 and 0.755, 0.796 and 0.824 for rDHI. Both IMRT and VMAT techniques delivered high conformal dose distributions in spine stereotactic radiosurgery. However, if the target volume includes the vertebral body, pedicle, and transverse process, IMRT planning resulted in insufficient conformity index, compared to VMAT planning. Nevertheless, IMRT technique was more effective in reducing the maximum spinal cord dose compared to RA1 and RA2 techniques at most sites.