• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.55-64
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• 1995

During sleep, relatively major respiratory physiological changes occur in healthy subjects. The contributions and interactions of voluntary and metabolic breathing control systems during waking and sleep are quite different Alterations of ventilatory control occur in chemosensitivity, response to mechanical loads, and stability of ventilation. The activities of intercostal muscles and muscles involved in regulating upper airway size are decreased during sleep. These respiratory physiological changes during sleep compromise the nocturnal ventilatory function, and sleep is an important physiological cause of the nocturnal alveolar hypoventilation. There are several causes of chronic alveolar hypoventilation including cardiopulmonary, neuromuscular diseases. Obstructive sleep apnea syndrome (OSAS) is an important cause of nocturnal hypoventilation and hypoxia. Coexistent cardiopulmonary or neuromuscular disease in patients with OSAS contributes to the development of diurnal alveolar hypoventilation, diurnal hypoxia and hypercapnia. The existing data indicates that nocturnal recurrent hypoxia and fragmentation of sleep in patients with OSAS contributes to the development of systemic hypertension and cardiac bradytachyarrhythmia, and diurnal pulmonary hypertension and cor pulmonale in patients with OSAS is usually present in patients with coexisting cardiac or pulmonary disease. Recent studies reported that untreated patients with OSAS had high long-term mortality rates, cardiovascular complications of OSAS had a major effect on mortality, and effective management of OSAS significantly decreased mortality.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.219-228
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• 2003

Background:Liquid nitrogen freezing techniques have already met with widespread success in biology and medicine as a means of long-term storage for cells and tissues. The use of cryoprotectants such as glycerol and dimethylsulphoxide to prevent ice crystal formation, with carefully controlled rates of freezing and thawing, allows both structure and viability to be retained almost indefinitely. Cryopreservation of various tissues has various con-trolled rates of freezing. Material and Method: To find the optimal freezing curve and the chamber temperature, we approached the thermodynamic calculation of tissues in two ways. One is the direct calculation method. We should know the thermophysical characteristics of all components, latent heat of fusion, area, density and volume, etc. This kind of calculation is so sophisticated and some variables may not be determined. The other is the indirect calculation method. We performed the tissue freezing with already used freezing curve and we observed the actual freezing curve of that tissue. And we modified the freezing curve with several steps of calculation, polynomial regression analysis, time constant calculation, thermal response calculation and inverse calculation of chamber temperature. Result: We applied that freezing program on mesenchymal stem cell, chondrocyte, and osteoblast. The tissue temperature decreased according to the ideal freezing curve without temperature rising. We did not find any differences in survival. The reason is postulated to be that freezing material is too small and contains cellular components. We expect the significant difference in cellular viability if the freezing curve is applied on a large scale of tissues. Conclusion: This program would be helpful in finding the chamber temperature for the ideal freezing curie easily.

• Journal of Life Science
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• v.19 no.12
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• pp.1841-1846
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• 2009

Menopause is often associated with the incidence of several chronic diseases including osteoporosis, cardiovascular disease, and obesity. Hormone replacement therapy (HRT) is an effective regimen that has been found to prevent these diseases in postmenopausal women. However, HRT is accompanied by an increased risk of unfavorable outcomes. Therefore, this study was conducted to evaluate the effects of Ecklonia cava, a kind of seaweed, extract on bone turnover markers in symptomatic menopausal women. For this study, the following four groups of 9-week-old Sprague-Dawley rats were evaluated over 6 weeks: normal rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with Ecklonia cava extracts. The optimum extraction temperature and solvent of Ecklonia cava were found to be $80^{\circ}C$ and 80% ethanol. We measured the osteocalcin and CTx content, enzyme ALP activity in serum and collagen content in the cartilage, bone, skin and lungs. We found that the levels of indicators of bone metabolism such as ALP, osteocalcin and CTx were lower in rats in the Ecklonia cava extract group than the OVX-CON group. In addition, the collagen contents in the bone, cartilage, skin and lungs decreased in response to ovariectomy, but the levels of collagen were greater in the bone of rats that were treated with Ecklonia cava extract than in the bone of rats in the OVX-CON group. According to these results, we were able to know the effects of Ecklonia cava extract on bone aging in ovariectomized rats. Consequently, we expect Ecklonia cava extract to have an effect on bone aging in postmenopausal women.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.648-654
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• 2000

Background: Cardiopulmonary bypass during open heart surgery causes systemic inflammatory respose. IL-10 is an anti-inflammatory cytokine that inhibits inflammatory process and protects organ function by down regulation of pro-inflammatory cytokine release and maintenance of blood level balance with pro-inflammatory cytokines. Mateial and Method: Plasma IL-10 levels were measured and analyzed in 22 patients who underwent open heart surgery (11 cases of coronary artery bypass graft, 11 cases of valve replacement) under cardiopulmonary bypass since 1988 January to July at Department of Thoracic and Czardiovascular surgery, Yeungnam University Hospital. 1g of methylprednisolone was administrated to thirteen patients randomly. Blood samp.es were taken and collected at the time of induction of anesthesia, 10 min before cardiopulmonary bypass, 10 min after starting of CPB, 10 min aftr aortic cross clamping, 10 min after ACC release, and 10 min, 2 hours, and `5 hours after CPB respectively. The plasma levels of IL-10 were determined by enzyme-linked immunosorbent assays(ELISA). Wilcoxon-Raule Sum test was used for statistical analysis. Result: In all 22 patients, cardiopulmonary bypass time was used for statistical analysis. Result: In all 22 patients, cardiopulmonary bypass time was 171$\pm$41.4 min and aortic cross clamp time was 118$\pm$36.5 min. Peak IL-10 level was achieved at 10 min after ACC(361.0$\pm$52.81pg/ml) and was decreased sharply at 2 hours after CPB. Peak IL-10 level was correlated positively with aortic cross clamp time(p=0.011); however, it did not correlated with bypass time(p=0.181). In valve replacement group, mean IL-10 level at peak point was 567.89$\pm$107.69 pg/ml and was significantly higher than that of coronary artery bypass group(205.67$\pm$192.70 pg/ml)(p<0.001). ACC time in valve replacement group was significantly longer than that of coronary artery bypass group(p<0.01), however, bypass time was not(p=0.212). Thirteen patients with steroid pretreatment before starting of CPB showed relatively higher plasma IL-10 level than in control group, however, no statistical significance was noted(p=0.19). Conclusion: plasma level of IL-10 was increased in association with cardiopulmonary bypass and revealed peak at 10 min after ACC release. IL-10 level was correlated positively with ACC time. Therefore, systemic inflammatory respeonse in association with cardiopulmonary bypass could be decreased by reducing ACC time during cardiac surgery.

• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.334-338
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• 2008

Solitary fibrous tumors of the pleura (SFTPs) are relatively rare tumors that originate from the mesenchymal cells of the submesothelial tissue of the pleura. Patients with SFTPs are often asymptomatic, while some patients experience pleuritic chest pain, cough and/or dyspnea. We report here on a case of SFTP, and the patient presented with septic shock and respiratory failure that required mechanical ventilation. A 68-year-old woman was admitted for the evaluation of her dyspnea and generalized edema. Chest imaging studies showed an 18 cm-sized voluminous mass occupying the right thoracic cavity with anterior displacement of hilar structures and atelectasis of the right lung. Immediately after admission, she developed pneumonia and septic shock that required antibiotics and mechanical ventilation. She displayed a partial response to medical treatment, and then complete excision of the tumor was performed and the pathologic examination revealed benign SFTP. Afterward, she fully improved without evidence of recurrence until now.

• The Korean Journal of Pain
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• v.6 no.2
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• pp.231-236
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• 1993

Clonidine, a centrally-acting antihypertensive agent known to reduce central sympathetic outflow and modulate presynaptic transmitter's release, has shown to suppress central noradrenergic hyperactivity induced by immobilization stress in animals, by decreasing the MAC of halothane and the dose of narcotics required to prevent reflex cardiovascular response to noxious stimuli, and to have potent analgesic properties in humans. These characteristics suggest that clonidine might be a useful adjunct to the anesthetic management of patients with preexisting hypertension. Accordingly, we determined the clinical efficacy and safety on analgesia, sedation and hemodynamic stability in the perioperative period. Thirty patients(ASA physical status II-III) with a history of arterial hypertension, scheduled for elective orthopedic surgery were randomly assigned to two groups. We applied CPA-clonidine patch($6.9\;mg/cm^2$, 0.2 mg delivered daily) or placebo patch to each groups, 48 hours prior to induction of anesthesia. Antihypertensive medication was continued until the morning of the scheduled surgery. All patients received premedication of atropine and lorazepam, and induced anesthesia with thiopental and succinylcholine, and maintained with enflurane and 50% nitrous oxide, while sustaining the BP and pulse rate at acceptable range. For the relief of pain postoperatively, diclofenac and fentanyl were administered intramuscularly on demand. The results were as follows: 1) The change of hemodynamic responses in clonidine group was less compared to the placebo group. 2) Intraoperative anesthetic requirement for enflurane in clonidine group were significantly lower than placebo group. 3) Postoperative analgetic requirement in clonidine group were significantly lower than placebo group. In clonidine group, 5 cases out of 15 cases were required no analgetics, and the incidence of administration of additional fentanyl was decreased to 5 cases, comparing with 10 cases in placebo group.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.973-979
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• 2000

A glycogen storage disease(GSD) type I is a metabolic disease caused by a deficiency in one of the components of the glucose-6-phosphatase(G-6-Pase) system. This disorder results in hypoglycemia, hepatomegaly, lactic acidemia, hyperlipidemia, and hyperuricemia. Comon long(-)term complications include growth retaradation, gout, hepatic adenomas, osteoporosis and renal disease. However the cardiovascular system is rarely involved, and only six cases of pulmonary hypertension associated with GSD I have been reported in the literature. We experienced a case of pulmonary hypertension with type I GSD. A 31-year-old rnan, who had discovered type I GSD and received portocaval shunt operation 22 years ago, was admitted to the hospital with the chief complaint of dyspnea. Echocardiographic examination and cardiac catheterization revealed severe pulmonary hypertension. Nitric oxide and oral prostacycline derivative(beraprost) were tried without acute favorable response. After one year with beraprost, dyspnea, exercise capacity and hemodynamic parameters were improved. We report this case with a review of the literature.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.39-48
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• 2014

Objective: This entire study has two parts. Study I aimed to develop a psychological assessment scale and the study II aimed to investigate the effects of LFN (low frequency noise) on the psychological responses in humans, using the scale developed in the study I. Background: LFN is known to have a negative impact on the functioning of humans. The negative impact of LFN can be categorized into two major areas of functioning of humans, physiological and psychological areas of functioning. The physiological impact can cause abnormalities in threshold, balancing and/or vestibular system, cardiovascular system and, hormone changes. Psychological functioning includes cognition, communication, mental health, and annoyance. Method: 182 college students participated in the study I in development of a psychological assessment scale and 42 paid volunteers participated in the study II to measure psychological responses. The LFN stimuli consisted of 12 different pure tones and 12 different 1 octave-band white noises and each stimulus had 4 different frequencies and 3 different sounds pressure levels. Results: We developed the psychological assessment scale consisting of 17 items with 3 dimensions of psychological responses (i.e., perceived physical, perceived physiological, and emotional responses). The main findings of LFN on the responses were as follows: 1. Perceived psychological responses showed a linear relation with SPL (sound pressure level), that is the higher the SPL is, the higher the negative psychological responses were. 2. Psychological responses showed quadric relations with SPL in general. 3. More negative responses at 31.5Hz LFN than those of 63 and 125Hz were reported, which is deemed to be caused by perceived vibration by 31.5Hz. 'Perceived vibration' at 31.5Hz than those of other frequencies of LFN is deemed to have amplified the negative psychological response. Consequently there found different effects of low frequency noise with different frequencies and intensity (SPL) on multiple psychological responses. Conclusion: Three dimensions of psychological responses drawn in regard to this study differed from others in the frequencies and SLP of LFN. Negative psychological responses are deemed to be differently affected by the frequency, SPL of the LFN and 'feel vibration' induced by the LFN. Application: The psychological scale from our study can be applied in quantitative psychological measurement of LFN at home or industrial environment. In addition, it can also help design systems to block LFN to provide optimal conditions if used the study outcome, .i.e., the relations between physical and psychological responses of LFN.

• Journal of Chest Surgery
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• v.34 no.10
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• pp.745-753
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• 2001

capillary leak syndrome and organ dysfunction in infants. Removing harmful cytokines and complement anaphylatoxins after cardiopulmonary bypass may attenuate this response. This study was conducted to see if the modified ultrafiltration and postoperative peritoneal dialysis can reduce plasma inflammatory mediators in pediatric cardiac surgery. Material and Method: 30 infants (age 1.1 to 12.6 months) who underwent closures of ventricular septal defect using cardiopulmonary bypass (CPB) were enrolled in this study. These patients were divided into three groups; 10 patients selected randomly underwent modified ultrafiltration (Group U), 10 with small body weights ($\leq$5 kg) received postoperative peritoneal dialysis (Group P), and 10 patients did not undergo modified ultrafiltration nor receivcd peritoneal dialysis (Group C). Serum samples were obtained before and after CPB, and after peritoneal dialysis. Effluents sample were also obtained after modified ultrafiltration or peritoneal dialysis. C3a and interleukin-6 (IL-6) were measured by radioimmunoassay and enzyme-linked immunosorbent assay respectively. Result: There was no differences in CPB time, aortic cross-clamping title, and lowest temperature during CPB. The effluents of peritoneal dialysis contained significant amount of C3a and IL-6, but there was no definitive decrease of serum concentration of C3a and IL-6. The effluents of modified ultrafiltration had some amount of C3a and negligible IL-6, and there was no decrease of serum concentration of these (actors. Conclusion: The effluents of peritoneal dialysis contained significant amount of proinflammatory cytokine, IL-6 and complement, C3a. However this study failed to elucidate the decrease in serum levels of these factors. The modified ultrafiltration also was not able to reduce the serum levels of C3a or IL-6 in our study as well.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.384-397
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• 2021

Background: With volatile organic compounds (VOCs) containing aromatic and halogenated hydrocarbons such as benzene, toluene, and xylene that can adversely affect the respiratory and cardiovascular systems when a certain concentration is reached, it is important to accurately evaluate the source and the corresponding health risk effects. Objectives: The purpose of this study is to provide scientific evidence for the city of Seoul's VOC reduction measures by confirming the risk of each VOC emission source. Methods: In 2020, 56 VOCs were measured and analyzed at one-hour intervals using an online flame ionization detector system (GC-FID) at two measuring stations in Seoul (Gangseo: GS, Bukhansan: BHS). The dominant emission source was identified using the Positive Matrix Factorization (PMF) model, and health risk assessment was performed on the main components of VOCs related to the emission source. Results: Gasoline vapor and vehicle combustion gas are the main sources of emissions in GS, a residential area in the city center, and the main sources are solvent usage and aged VOCs in BHS, a greenbelt area. The risk index ranged from 0.01 to 0.02, which is lower than the standard of 1 for both GS and BHS, and was an acceptable level of 5.71×10^-7 to 2.58×10^-6 for carcinogenic risk. Conclusions: In order to reduce the level of carcinogenic risk to an acceptable safe level, it is necessary to improve and reduce the emission sources of vehicle combustion and solvent usage, and eco-car policies are judged to contribute to the reduction of combustion gas as well as providing a response to climate change.