• Annals of Clinical Neurophysiology
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• v.4 no.1
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• pp.38-43
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• 2002

Background & Purpose : Dynamic susceptibility contrast MR imaging, one method of perfusion MRI, was developed to define cerebral hemodynamic status with good anatomical resolution. The authors investigated hemodynamic parameters using this imaging method, in an effort to identify hemodynamic changes on the remote crossed cerebellum of patients with a supratentorial infarct. Methods : Dynamic susceptibility contrast MR imaging was performed in 15 patients with only unilateral supratentorial infarcts. Imaging was obtained at the anatomic level of the cerebellum. rCBF, rCBV, MTT and TP were determined over both cerebellar hemispheres of interest. Results : The rCBF and rCBV values of the contralateral cerebellar hemisphere were significantly more decreased than those of the ipsilateral cerebellar hemisphere in 12 patients(p=0.028, 0.033). MTT and TP values of the contralateral and ipsilateral cerebellar hemispheres didn't reveal any differences(p=0.130, 0.121). Conclusions : The results of this work suggest that the region which are remote from the ischemic brain lesion shows no changes of MTT or TP but show decrease of rCBF and rCBV, mean to diaschisis, it also demonstrates that perfusion MRI is an easily available method to evaluate the hemodynamic status of the brain.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• Journal of Chest Surgery
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• v.25 no.2
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• pp.125-130
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• 1992

To evaluate the effect of oxygenation[95% O2+5% CO2] of St. Thomas Hospital No.2 cardioplegic solution[Plegisol], 20 isolated perfused rat hearts were studied under hyp-othermic[20oC] ischemic arrest for 2 hours with infusion of cardioplegic solution every 30 minutes throughout the ischemic period. Ten isolated hearts were studied with the oxygenated cardioplegic solution and 10 another isolated hearts with the nonoxygenated one. Mean oxygen tensions of the nonoxygenated and oxygenated cardioplegic solutions were 150mmHg and 470mmHg, respectively. Two in 10 hearts infused with the nonaxygenated cardioplegic solution were not recovered from nonworking heart due to persistent ventricular fibrillation. In comparing hem-odynamic parameters between both groups, the mean postischemic recovery[expressed as a percentage of its preischemic control value] was significantly greater with the oxygenated solution[in 10 recovered hearts] than the nonoxygenated solution[in 8 recovered hearts] [95.9$\pm$1.8% compared with 88.5$\pm$2.9% in peak aortic pressure, p<0.05, 75.7$\pm$5.2% compared with 43.5$\pm$6.5% in aortic flow, p<0.01, 75.5$\pm$4.6% compared with 54.1$\pm$5.6% in cardiac output, p<0.01, 78.3$\pm$4.6% compared with 60.3$\pm$4.6% compared with 60.3$\pm$6.2% in stroke volume, p<0.05, and 80.4$\pm$5.3% compared with 58.6$\pm$7.0% in dP/dT, p<0.05]. It is concluded that oxygenation of St. Thomas Hospital No.2 cardioplegic solution improves cardiac electrical stability and postischemic hemodynamic recovery after ischemic arrest in the isolated perfused rat heart.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.231-242
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• 2020

The thesis presents a system that continuously collects the human body's physiological vital information at rest with sensors and ICT information technology and predicts diabetes using the collected information. it shows the artificial neural network machine learning method and essential basic variable values. The study method analyzed the correlation between heart rate measurements of BCG and ECG sensors in 20 DM- and 15 DM+ subjects. Artificial Neural Network (ANN) machine learning program was used to predictability of diabetes. The input variables are time domain information of HRV, heart rate, heart rate variability, respiration rate, stroke volume, minimum blood pressure, highest blood pressure, age, and sex. ANN machine learning prediction accuracy is 99.53%. Thesis needs continuous research such as diabetic prediction model by BMI information, predicting cardiac dysfunction, and sleep disorder analysis model using ANN machine learning.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.5
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• pp.275-280
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• 2008

A brief ischemic insult induces significant protection against subsequent massive ischemic events. The molecular mechanisms known as preconditioning (PC)-induced ischemic tolerance are not completely understood. We investigated whether kinetic changes of cyclooxygenase (COX)-2 during reperfusion time-periods after PC were related to ischemic tolerance. Rats were given PC by occlusion of middle cerebral artery (MCAO) for 10 min and sacrificed after the indicated time-periods of reperfusion (1, 2, 4, 8, 12, 18 or 24 h). In PC-treated rats, focal ischemia was induced by occlusion of MCA for 24 h and brain infarct volume was then studied to determine whether different reperfusion time influenced the damage. We report that the most significant protection against focal ischemia was obtained in rats with 8 h reperfusion after PC. Administration of indomethacin (10 mg/kg, oral) or rofecoxib (5 mg/kg, oral) 48 h prior to PC counteracted the effect of PC. Immunohistochemical analysis showed that COX-2 and HO-l protein were induced in PC-treated rat brain, which was significantly inhibited by rofecoxib. Taken together, we concluded that the kinetic changes of COX-2 expression during the reperfusion period after PC might be partly responsible for ischemic tolerance.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.271-277
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• 1999

Safety evaluation of LB71350, a new HIV-1 protease inhibitor, was performed in mice, rats and dogs. For the general behavior of mice, LB71350 at an oral dose of 200 mg/kg did not show any significant effects on muscle tone and locomotor activity. In terms of central nervous system, at oral doses of 200 mg/kg and 1000 mg/kg, LB71350 inhibited acetic acid-induced pain response approximately 41% and 83% of control. respectively. At oral doses of 200 mg/kg and 500 mg/kg, it reduced the rectal body temperature in rats. Pentylenetetrazole-induced seizure in mice was slightly potentiated by oral administration of LB71350 at doses ranging from 200 mg/kg to 1000 mg/Ag. Single or five day treatment of LB71350 doubled the hexobarbital- induced sleeping time in mice at oral doses ranging from 50 mg/kg to 500 mg/kg. It did not cause any effects on gastric secretion and acidity in rat at oral doses of 200 mg/kg and 1000 mg/kg and also it did not change intestinal motility in mice up to 1000 mg/kg. Blood coagulation indices such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT) in rats were not affected by the treatment of LB71350 up to 500 mg/kg. LB71350 caused no significant effects on the cardiac output, stroke volume, heart rate, and mean blood pressure when infused intravenously to the anesthetized rats and dogs. Taken together, LB71350 at high oral doses caused significant pharmacological effects on the central nervous system and the hexobarbital-induced sleeping time.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.341-349
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• 2009

Objective : The purpose of this study was to identify independent predictors of mortality and functional recovery in patients with primary intracerebral hemorrhage (PICH) and to improve functional outcome in these patients. Methods : Data were collected retrospectively on 585 patients with supratentorial PICH admitted to the Stroke Unit at our hospital between 1st January 2004 and the 31st July 2008. Using multivariate logistic regression analysis, the associations between all selected variables and 30-day mortality and 90-day functional recoveries after PICH was evaluated. Results : Ninety-day functional recovery was achieved in 29.1% of the 585 patients and 30-day mortality in 15.9%. Age (OR=7.384, p=0.000), limb weakness (OR=6.927, p=0.000), and hematoma volume (OR=5.293, p=0.000) were found to be powerful predictors of 90-day functional recovery. Furthermore, initial consciousness (OR=3.013, p=0.014) hematoma location (lobar, OR=2.653, p=0.003), ventricular extension of blood (OR=2.077, p=0.013), leukocytosis (OR=2.048, p=0.008), alcohol intake (drinker, OR=1.927, p=0.023), and increased serum aminotransferase (OR=1.892, p=0.035) were found to be independent predictors of 90-day functional recovery after PICH. On the other hand, a pupillary abnormality (OR=4.532, p=0.000) and initial unconsciousness (OR=3.362, p=0.000) were found to be independent predictors of 30-day mortality after PICH. Conclusion : The predictors of mortality and functional recovery after PICH identified during this analysis may assist during clinical decision-making, when advising patients or family members about the prognosis of PICH and when planning intervention trials.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.3
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• pp.193-197
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• 2016

Background: Some patients with special needs exhibit intellectual disability, including deficits in cognitive skills and decreased quality of life. The purpose of this study was to retrospectively compare changes in body composition and hemodynamics during general anesthesia in patients with and without special needs. Methods: The backgrounds of patients who underwent oral maxillofacial surgery under general anesthesia were recorded from medical records. Intracellular water (ICW), extracellular water (ECW), stroke volume variation (SVV), and heart rate (HR) were recorded for 3 h after the start of anesthesia. Categorical data were compared using an unpaired t-test, and a P-value of less than 0.05 was regarded as significant. Numerical data were compared using the Bonferroni correction, and a P-value of less than 0.0125 was regarded as significant. Results: A total of 21 patients were included in the study: 10 patients without special needs (non-S-group) and 11 patients with special needs (S-group). There were no significant differences in patients' backgrounds, except with regard to height (P = 0.03). In both groups, ICW and ECW were maintained, although they were lower in the S-group compared to the non-S-group. SVV was maintained in both groups, although it was higher in the S-group than the non-S-group. HR was significantly lower in the S-group 1 h after induction of anesthesia (P < 0.003). Conclusions: Changes in hemodynamics due to body fluid imbalance should be monitored during general anesthesia, especially for patients with special needs.

• Journal of Magnetics
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• v.17 no.3
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• pp.229-232
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• 2012

This study examined the correlation between MR cine and myocardium Single-photon emission computed tomography (SPECT) by comparing the measured cardiac ejection fractions. The usefulness of cardiac MRI was also evaluated. Ten patients (8 men, 2 women and average age of 58.6 years), who underwent a myocardium SPECT scan and cardiac cine MRI scan among patients who visited the hospital for the chief complaint of cardiac disorder from June 1, 2010 to February 10, 2011, were enrolled in this study. The cardiac ejection fraction was calculated from the images obtained in both scans. The data was used to examine the correlation. The regression equation the cardiac ejection fraction values of the 10 patients obtained in myocardium SPECT and MRI cine was Y = 1.12X-8.91 ($R^2$ = 0.78, significance of F = 0.001639, and confidence level of 95%). The results were significant when the cardiac ejection fraction obtained from MRI cine was compared with that obtained from myocardium SPECT. Overall, a cardiac examination using MRI enables an investigation of not only the ejection fraction but also the ED and ES volumes, stroke volume, wall thickness, and wall thickening in a higher spatial resolution despite the examination being conducted once. This examination is believed to be very useful for diagnosing patients with cardiac disease.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.257-269
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• 2021

The purpose of this study is to collect biosignal data in a non-invasive and non-restrictive manner using a BCG (Ballistocardiogram) sensor, and utilize artificial intelligence machine learning algorithms in ICT and high-performance computing environments. And it is to present and study a method for developing and validating a data-based blood glucose prediction model. In the blood glucose level prediction model, the input nodes in the MLP architecture are data of heart rate, respiration rate, stroke volume, heart rate variability, SDNN, RMSSD, PNN50, age, and gender, and the hidden layer 7 were used. As a result of the experiment, the average MSE, MAE, and RMSE values of the learning data tested 5 times were 0.5226, 0.6328, and 0.7692, respectively, and the average values of the validation data were 0.5408, 0.6776, and 0.7968, respectively, and the coefficient of determination (R²) was 0.9997. If research to standardize a model for predicting blood sugar levels based on data and to verify data set collection and prediction accuracy continues, it is expected that it can be used for non-invasive blood sugar level management.