• Title/Summary/Keyword: Cortical activity

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LOCALIZATION OF BONE MATRIX GENE mRNA IN REGENERATING BONE TISSUE DURING THE GUIDED BONE REGENERATION (골재생유도술에 의한 골재생과정에서의 골기질 유전자 발현 양상)

  • Lee, Chang-Kon;Ryoo, Hyun-Mo;Shin, Hong-In
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.21 no.3
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    • pp.240-248
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    • 1999
  • To investigate the expression pattern of noncollagenous bone matrix proteins such as osteonectin(OSN), osteopontin(OPN) and osteocalcin(OSC) mRNA during bony healing procedure induced by guided bone regeneration method, we made artificial defects on bilateral femur of rats. Then induced bony healing by application of a nonabsorbable PTFE membrane in experimental sites and without its application in control sites for 3 weeks. The mRNA expression pattern at specimens obtained at 1, 2 and 3 weeks after operation was detected by in situ hybridization method using its antisense mRNA probes. The experimental sites revealed more rapid and favorable bony healing than control sites and new bone formation was limited within defected area by inhibitory activity of bone marrow cells. In experimental sites, the OSN and OSC mRNA were expressed strongly on osteoblasts of regenerating cortical bone at 1st week and on osteoblasts lining the trabecular bone in marrow space at 3rd week, whereas, in control sites, their expression were noted on osteoblasts lining the reactively formed sponge bones at 2nd and 3rd week. In addition, the OPN mRNA was expressed on osteoblasts and osteoclasts at sites of remodeling and osteocytes of remained trabecular bone of defected area in experimental sites and on macrophages at 1st week and osteoclasts at sites of remolding at 2nd and 3rd week in control sites. The above findings suggest that the more rapid and favorable bony healing might be induced by blocking of invading fibrous connective tissue into bony defects. And the earlier expression of OSN and OSC mRNA on osteoblasts of experimental sites suggest that the formation and resorption of regenerating bone was more rapidly progressed in confined spaces made by applicate membranes.

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Effectiveness of Focal Muscle Vibration on Upper Extremity Spasticity and Function for Stroke Patients : A Systematic Review (뇌졸중 환자의 상지 경직 감소와 기능 향상을 위한 국소 진동자극의 효과에 대한 체계적 고찰)

  • Won, Kyung-A;Park, Ji-Hyuk
    • Therapeutic Science for Rehabilitation
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    • v.7 no.3
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    • pp.23-33
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    • 2018
  • Objective : This systematic review aimed to investigate the effect of focal muscle vibration in patients with post-stroke spastic hemiplegia. Methods : We searched literature published between April 2009 and October 2017 using PubMed and RISS databases. The main search terms were Vibration therapy, Focal vibration, Somatosensory, Upper limb, and Spasticity after stroke. Based on inclusion/exclusion criteria, 6 articles were selected. Results : Articles on focal muscle vibration intervention ranged from evaluation of application-only vibration to muscle vibration with task-oriented activity. Intervention effects on upper extremity spasticity and function and activities of daily living were assessed. There were significant effects on upper extremity spasticity, function, and cortical excitability. Conclusions : This study can provide information on focal muscle vibration for use by clinical therapists. However, further studies are needed to identify the optimal stimulation site and frequency/amplitude of application to maximize the effects of focal muscle vibration.

Effect of Salviae Radix on Impairment of Membrane Transport Function in Rabbits with Myoglobinuric Acute Renal Failure (마이오글로빈뇨성 급성 신부전 토끼에서 신장 세포막 수송 기능 장애에 대한 단삼의 효과)

  • Ji-Cheon, Jeong;Hyun-Soo, Kim
    • The Journal of Korean Medicine
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    • v.21 no.3
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    • pp.119-128
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    • 2000
  • This study was carried out to determine if Salviae Radix extract (SRE) exerts protective effect against alterations in membrane transport function in rabbits with rhabdomyo lysis-induced acute renal failure. Acute renal failure was induced by intramuscular administration of glycerol (50%, 10 ml/kg). GFR in the glycerol-injected animals was reduced to 11% of the basal value and the fractional $Na^{+}$ excretion was increased to 7.8-fold, indicating generation of acute renal failure. When animals received SRE pretreatment for 7 days prior to glycerol injection, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased more than 43-fold and 27-fold, respectively, in rabbits treated with glycerol alone. However, they were increased to 17-and 4.3-fold, respectively, in SRE-pretreated rabbits, and these values were significantly lower than those in rabbits treated with glycerol alone. Uptakes of glucose and phosphate in purified isolated brush-border membrane, the $Na^{+}-K^{+}-ATPase$ activity in microsomal fraction, and cellular ATP levels all were reduced in rabbits treated with glycerol alone. Such changes were prevented by SRE pretreatment. Uptakes of organic ions, PAH and TEA, in renal cortical slices were inhibited by the administration of glycerol, which was prevented by SRE pretreatment. Pretreatment of an antioxidant DPPD significantly attenuated the increase in the fractional excretion of glucose and phosphate induced by rhabdomyolysis. These results indicate that rhabdomyolysis causesimpairment inreabsorption of solutes in the proximal tubule via the generation of reactive oxygen species, and SRE pretreatment may provide the protection against the rhabdomyolysis-induced impairment by its antioxidant action.

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Changes in the Sensory Function after Transcranial Direct Stimulation on Dorsolateral Prefrontal Cortex Area (배외측전전두엽피질 영역에 경두개직류전류자극이 감각기능에 미치는 영향)

  • Min, Dong-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.445-452
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    • 2015
  • Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers a low-intensity direct current to the cortical areas, thereby facilitating or inhibiting spontaneous neuronal activity. This study was designed to examine the changes in various sensory functions after tDCS. A single-center, single-blinded, randomized trial was conducted to determine the effect of a single session (August 4 to August 29) of tDCS with the current perception threshold (CPT) in 50 healthy volunteers. Nerve conduction studies (NCS) were performed in relation to the median sensory and motor nerves on the dominant hand to discriminate peripheral nerve lesions. The subjects received anodal tDCS with 1mA for 15 minutes under two different conditions, with 25 subjects in each group. The conditions were as follows: tDCS on the dorsolateral prefrontal cortex (DLPFC) and sham tDCS on DLPFC. The parameters of the CPT was recorded with a Neurometer$^{(R)}$ at frequencies of 2000, 250 and 5 Hz in the dominant index finger to assess the tactile sense, fast pain and slow pain, respectively. In the test to measure the CPT values of the DLPFC in the anodal tDCS group, the values increased significantly in all of 250 and 5 Hz. All CPT values decreased for the sham tDCS. These results showed that DLPFC anodal tDCS can modulate the sensory perception and pain thresholds in healthy adult volunteers. This study suggests that tDCS may be a useful strategy for treating central neurogenic pain in rehabilitation medicine.

Atrial Natriuretic Peptide Attenuates the Development of Hypertension in 2-Kidney, 1-Clip Goldblatt Rats (2-Kidney, 1-Clip Goldblatt 흰쥐에 있어서 고혈압 발생에 미치는 Atrial Natriuretic Peptide 의 영향)

  • Lee, Jong-Eun
    • The Korean Journal of Physiology
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    • v.23 no.1
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    • pp.43-49
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    • 1989
  • Effects of atrial natriuretic peptide (ANP) on the development of hypertension in 2-kidney, 1-clip (2-K, 1-C) rats were examined. In one group of rats, ANP infusion (500 ng/hr, iv) started immediately after clipping the renal artery. Another group of rats with one kidney-clipped was without ANP infusion and served as a control. Blood pressure was measured on days 4, 7, and 10 following clipping the renal artery. Upon the last blood pressure measurement finished, blood sample was collected by decapitation to measure plasma renin activity (PRA), and both kidneys were taken to weigh and to measure renin content. The ANP-infused group showed an attenuation of increases in blood pressure compared to the non-infused control group. PRA was lower in the ANP-infused group than in the non-infused group. Cortical renal renin content (RRC) of the clipped kidneys was not different between ANP-infused and non-infused groups. The clipped kidneys showed a higher RRC and weighed less than the non-clipped contralateral kidneys within each group. In contrast, sham-clipped rats did not show significant changes in any of the parameters examined regardless of whether ANP was infused or not. These results demonstrate that chronic ANP infusion does not prevent but does attenuate the development of hypertension in 2-K, 1-C rats. It is suggested that ANP plays a role in the long-term regulation of blood pressure, at least in part, by antagonizing the renin-angiotensin-system.

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The Clinical Usefulness of Electroencephalography : Comparison of Findings Electroencephalography with Findings of Brain Computed Tomography and Magnetic Resonance Imaging (뇌파의 임상적 유용성 : 뇌파소견과 뇌전산화 단층촬영 검사 및 뇌자기공명 영상검사 소견을 비교하여)

  • Kang, Dong-Woo;Lee, Young-Ho;Choi, Young-Hee;Chung, Young-Cho
    • Sleep Medicine and Psychophysiology
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    • v.3 no.2
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    • pp.1-17
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    • 1996
  • To demonstrate the clinical usefulness of electroencephalography (EEG) and factors increasing the usefulness of EEG, the authors evaluated each relationship between EEG related factors and clinical variables, and neuroimaging studies (CT and MRI)-related factors, and factors which are related with routine neurological examination for 207 patients who had been evaluated with both of EEG and neuroimaging study(CT or/and MRI). The results were as follows: 1) Abnormality of EEG findings had significant relationships with chief complaints, diagnosis, medication use, seizure attack, pathological reflex, and level of consciousness. However there were no significant correlations between abnormality of EEG findings and neuroimaging studies (CT and MRI)- related factors. 2) Laterality of EEG findings had significant relationships with abnormality, laterality, and focality of CT findings, and also with abnormality of MRI findings. But there were no significant correlations between laterality of EEG findings and clinical variables, and neurological examination-related factors. 3) Anterior-posterior distribution of EEG findings was significantly related with medication use. 4) Focality of EEG findings had significant relationships with sex, sensory dysfunction sign, and cerebellar dysfunction sign. But there were no significant correlations between focality of EEG findings and neuroimaging studies(CT and MRI) related factors. 5) Abnormal EEG pattern had significant correlations with various factors, such as age, chief complaints, duration from onset of symptom to taking MRI, seizure attack, abnormality and nature of lesion in CT findings, cortical atrophy in MRI findings, motor dysfunction sign, sensory dysfunction sign, and pathological reflex. 6) With abnormality on sleep activation, age, age of onset, seizure attack, ventricular enlargement in CT findings, and abnormality of MRI findings were significantly correlated. 7) With abnormality on hyperventilation activation, duration of illness and laterality of MRI findings were significantly correlated. Above results may suggest that abnormality of EEG findings is more closely related with functional change of the brain than structural changes of the brain and laterality of EEG findings is vice versa. And also that medication use has an influence on anterior versus posterior distribution of EEG findings and focality of EEG findings is not related with structural changes of the brain. Activation with sleep may be effective to show age differences and provocation of seizure activity and hyperventilation may be effective to detect the abnormal EEG findings by cerebrovascular insufficiency.

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Immunostimulation of C6 Glioma Cells Induces Nitric Oxide-Dependent Cell Death in Serum-Free, Glucose-Deprived Condition

  • Shin, Chan-Young;Choi, Ji-Woong;Ryu, Jae-Ryun;Ryu, Jong-Hoon;Kim, Won-Ki;Kim, Hyong-Chun;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • v.8 no.2
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    • pp.140-146
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    • 2000
  • Recently, we reported that immunostimulation of primary rat cortical astrocyte caused stimulation of glucose deprivation induced apoptotic cell death. To enhance the understanding of the mechanism of the potentiated cell death of clucose-deprived astrocyte by immunostimulation, we investigated the effect of immunostimulation on the glucose deprivation induced cell death of rat C6 glioma cells. Co-treatment of C6 glioma cells with lipopolysaccharide (LPS, $1\;{\mu}\textrm{g}/ml$) and interferon ${\gamma}(IFN{\gamma},\;100U/ml)$ is serum free condition caused marked elevationo f nitric oxide production ($>50\;{\mu}M$). In this condition, glucose deprivation caused significant release of lactate dehdrogenase (LDH) from C6 glioma cells while control cells did not show LDH release. To investigate whether elevated level of nitric oxide is responsible for the enhanced LDH release in glucose-deprived condition, C6 glioma cells were treated with 3-morphorinosydnonimine (SIN-1) and it was observed that SIN-1 caused increase in LDH release from glucose-deprived C6 glioma cells. Treatment of C6 glioma cells with $25\;{\mu}M$ of pyrrolidinedithiocarbamate (PDTC) which inhibit Nuclear factor kB (NF-kB) activation, caused complete inhibition of nitric oxide production. Treatment of C6 glioma cells with NO synthase inhibitors, $N^{G}$-nitro-L-arginine (NNA) or L-$N{\omega}$-nitro-L-arginine methyl ester (L-NAME), caused inhibition of nitric oxide production and also glucose deprivation induced cell death of cytokine-stimulated C6 glioma cells. In addition, diaminohydroxypyrimidine (DAHP, 5 mM) which inhibits the synthesis of tetrahydrobiopterine (BH4), one of essential cofactors for iNOS activity, caused complete inhibition of NO production from immunostimulated C6 glioma cells. The results from the present study suggest that immunostimulation causes potentiation of glucose deprivation induced death of C6 glioma cells which is mediated at least in part by the increased production of nitric oxide. The vulnerability of immunostimulated C6 glioma cells to hypoglycemic insults may implicate that the elevated level of cytokines in various ischemic and neurodegenerative diseases may play a role in their pathogenesis.

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Pharmacological Characterization of (10bS)-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline Oxalate (YSL-3S) as a New ${\alpha}_2$-Adrenoceptor Antagonist

  • Chung, Sung-Hyun;Yook, Ju-Won;Min, Byung-Jun;Lee, Jae-Yeol;Lee, Yong-Sup;Jin, Chang-Bae
    • Archives of Pharmacal Research
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    • v.23 no.4
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    • pp.353-359
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    • 2000
  • ${\alpha}_2$-Adrenoceptor antagonists, which can enhance synaptic norepinephrine levels by blocking feedback inhibition processes, are potentially useful in the treatment of disease states such. as depression, memory impairment, impotence and sexual dysfunction. (10bS)-1,2,3,5,6,10b-Hexahydropyrrolo[2,1-a]isoquinoline oxalate (YSL-3S) was evaluated in several in vitro biological tests to establish its pharmacological profile of activities as an ${\alpha}_2$-adrenoceptor antagonist. Saturation binding assay revealed that$^{3}[H]$rauwolscine bound to the $\alpha$$_2$-adrenoceptors with a Kd value of 6.3$\pm$0.5 nM and a Bmax value of 25l$\pm$39 fmol/mg protein in rat cortical synaptic membranes. Competitive binding assay showed that YSL-3S inhibited the binding of$^3[H]$rauwolscine (1 nM) in a concentration-dependent manner with a Ki value of 98.2$\pm$12.1 nM while it did not inhibit the binding of [$^3$H]cytisine (1.25 nM) to neuronal nicotinic cholinergic receptors. The Ki values of yohimbine, clonidine and norepinephrine for $^3[H]$rauwolscine binding were 15.8$\pm$1.0, 40.1$\pm$5.9 and 40.0$\pm$11.5 nM, respectively. In addition, the binding affinity of YSL-3S for ${\alpha}_2$-adrenoceptors was higher than that of its antipode and the racemic mixture. The functional activity of YSL-3S at the presynaptic ${\alpha}_2$-adrenoceptors was assessed using the prostatic portion of the rat vas deferens. Clonidine inhibited field-stimulated contractions of the vas deference in a dose-dependent manner. The presence of YSL-3S or yohimbine caused a parallel, rightward the dose-response curve of clonidine in a dose-dependent manner, indicating an antagonistic action at the presynaptic ${\alpha}_2$-adrenoceptors. The $pA_2$values of yohimbine and YSL-3S were 7.66$\pm$0.13 and 6.64$\pm$0.18, respectively. The results indicate that YSL-3S acts as a competitive antagonist at presynaptic ${\alpha}_2$ -adrenoceptors with a potency approximately ten times lower than yohimbine, but is devoid of binding affinity for neuronal nicotinic cholinergic receptors.

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Impact of Transcranial Direct Current Stimulation Combined With Constraint-Induced Movement Therapy on Upper Limb Function in Chronic Stroke: A Systematic Review (뇌졸중 환자의 상지기능 향상을 위한 경두개 직류 자극과 강제 유도 운동 치료의 결합 중재 효과에 대한 체계적 고찰)

  • Kim, Sun-Ho
    • Therapeutic Science for Rehabilitation
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    • v.8 no.4
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    • pp.7-18
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    • 2019
  • Objective : This systematic review aimed to investigate the impact of transcranial direct current stimulation combined with constraint-induced movement therapy (CIMT) in patients with stroke Methods : PubMed and NDSL databases were employed to review literature published between January 2009 and December 2018. The main search terms were "Transcranial direct current stimulation" or "tDCS," "Constraint-induced movement therapy" or "CIMT," "Upper extremity function," "Upper limb," and "Stroke." Based on the inclusion and exclusion criteria, 6 articles were selected. Furthermore, intervention effects on upper extremity function, activities of daily living, and cortical activity were assessed. Results : The current intensity, application time, and protocol of the CIMT varied the between studies. However, the intervention procedures to perform CIMT immediately after transcranial direct current stimulation was the same. Transcranial direct current stimulation combined with CIMT was effective in improving upper limb function and activities of daily living in patients with stoke and had a significant effect on cerebral cortex activation. Conclusions : This study provides information on transcranial direct current stimulation combined with CIMT for use by clinical therapists. Further studies are needed to standardize the stimulation time, current intensity, and electrode attachment position. Furthermore, randomized controlled trials, including long-term follow up, are needed for larger populations using the most appropriate CIMT protocol.

Morphologic Alterations in Amygdala Subregions of Adult Patients with Bipolar Disorder

  • Lee, Hyun-Jae;Han, Kyu-Man;Kim, Aram;Kang, Wooyoung;Kang, Youbin;Kang, June;Won, Eunsoo;Tae, Woo-Suk;Ham, Byung-Joo
    • Korean Journal of Biological Psychiatry
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    • v.26 no.1
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    • pp.22-31
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    • 2019
  • Objectives Previous studies have revealed inconsistent results on amygdala volume in adult bipolar disorder (BD) patients compared to healthy controls (HC). Since the amygdala encompasses multiple subregions, the subtle volume changes in each amygdala nucleus might have not been fully reflected in the measure of the total amygdala volume, causing discrepant results. Thus, we aimed to investigate volume changes in each amygdala subregion and their association with subtypes of BD, lithium use and clinical status of BD. Methods Fifty-five BD patients and 55 HC underwent T1-weighted structural magnetic resonance imaging. We analyzed volumes of the whole amygdala and each amygdala subregion, including the anterior amygdaloid area, cortico-amygdaloid transition area, basal, lateral, accessory basal, central, cortical, medial and paralaminar nuclei using the atlas in the FreeSurfer. The volume difference was analyzed using a one-way analysis of covariance with individual volumes as dependent variables, and age, sex, and total intracranial volume as covariates. Results The volumes of whole right amygdala and subregions including basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area in the right amygdala of BD patients were significantly smaller for the HC group. No significant volume difference between bipolar I disorder and bipolar II disorder was found after the Bonferroni correction. The trend of larger volume in medial nucleus with lithium treatment was not significant after the Bonferroni correction. No significant correlation between illness duration and amygdala volume, and insignificant negative correlation were found between right central nucleus volume and depression severity. Conclusions Significant volume decrements of the whole amygdala, basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area were found in the right hemisphere in adult BD patients, compared to HC group. We postulate that such volume changes are associated with altered functional activity and connectivity of amygdala nuclei in BD.