• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.238-246
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• 2001

Bone morphogenetic proteins(BMPs), members of the transforming growth factor $\beta$(TGF-$\beta$) superfamily were first identified as the factors that induce ectopic bone formation in vivo, when implanted into muscular tissue. Especially BMP-2 inhibits terminal differentiation of C2C12 myoblasts and converts them into osteoblast lineage cells. In the molecular mechanism of the signal transduction of TGF-$\beta$ and related factors, intracellular signaling proteins were identified as Smad. In previous study, it has been reported that Smad 1 and Smad 5, which belong to the R-Smad family mediate BMP signaling, were involved in the induction of osteoblast differentiation in C2C12 cells. To understnad the role of Smads involved in osteogenic transdifferentiation in C2C12 cell, in present study, after we stably transfected C2C12 cells with each. Smad(Smad 1,Smad 5) expression vector, cultured for 3 days and stained for alkaline phophatase activity. ALP activity positive cells appeared in the Smad 1, Smad 5 stably transfected cell even in the abscence of BMP. After transiently co-transfected C2C12 cells with each Smad expression vector and ALP promoter, it was examined that Smad 1 and Smad 5 expression vector had increased about 2 fold ALP promoter activity in the abscence of BMP. These result suggested that both Smad 1 and Smad 5 were involved in the intracellular BMP signals which induce osteoblast differentiation in C2C12 cells. The effect of BMP on C2C12 cells with Smad 1, Smad 5 transfected were studied by using northern blot analysis. the treatment of BMP upregulated ALP mRNA level in three groups, especially upregulation of ALP was larger in Smad 1, Smad 5 transfected cell than control group. Pretreatment with cycloheximide($10{\mu}g/ml$), a protein synthesis inhibitor resulted in blocking the ALP gene expression even in BMP(100ng/ml) treated cell. These results suggested that Smad increased the level of ALP mRNA via the synthesis of a certain transcriptional regulatory protein.

• Journal of Radiation Protection and Research
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• v.27 no.3
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• pp.147-154
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• 2002

Purpose : Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Materials and Methods : Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with a acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 co Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed lot estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. Results : The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within ${\pm}0.5%$. For elongated radiation field, the errors were limited to ${\pm}1.0%$. Conclusion : The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.37-44
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• 2001

Background: Sleep disorders are prevalent in the general population and in medical practice. Three diagnostic classifications for sleep disorders have been developed recently: The International Classification of Sleep Disorders (ICSD), The Diagnostic and Statistical Manual, 4th edition (DSM-IV) and The International Classification of Diseases, 10th edition (ICD-10). Few data have yet been published regarding how the diagnostic systems are related to each other. To address these issues, we evaluated the frequency of sleep disorder diagnoses by DSM-IV and ICSD and compared the DSM-IV with the ICSD diagnoses. Method: Two interviewers assessed 284 inpatients who had been referred for sleep problems in general units of Anam Hospital, holding an unstructured clinical interview with each patient and assigning clinical diagnoses using ICSD and DSM-IV classifications. Results: The most frequent DSM-IV primary diagnoses were "insomnia related to another mental disorder (61.1% of cases)" and "delirium due to general medical condition (26.8%)". "Sleep disorder associated with neurologic disorder (38.4% of cases)" was the most frequent ICSD primary diagnosis, followed by "sleep disorder associated with mental disorder (33.1%)". In comparing the DSM-IV diagnoses with the ICSD diagnoses, sleep disorder unrelated with general medical condition or another mental disorder in DSM-IV categories corresponded with these in ICSD categories. But DSM-IV "primary insomnia" fell into two major categories of ICSD, "psychophysiologic insomni" and "inadequate sleep hygiene". Of 269 subjects, 62 diagnosed with DSM-IV sleep disorder related to general medical condition or another mental disorder disagreed with ICSD diagnoses, which were sleep disorders not associated with general medical condition or mental disorder, i. e., "inadequate sleep hygiene", "environmental sleep disorder", "adjustment sleep disorder" and "insufficient sleep disorder". Conclusion: In this study, we found not only a similar pattern between DSM-IV and ICSD diagnoses but also disagreements, which should not be overlooked by clinicians and resulted from various degrees of understanding of the pathophysiology of the sleep disorders among clinicians. Non-diagnosis or mis-diagnosis leas to inappropriate treatment, therefore the clinicians' understanding of the classification and pathophysiology of sleep disorders is important.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.32-38
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• 2005

Objectives: Obstructive sleep apnea syndrome (OSAS) has drawn increasing attention as medical community has become to be aware of its co-morbidities and complications, especially cardiovascular complications and excessive daytime sleepiness with accident proneness. As of now, polysomnography is the standard tool to diagnose sleep apnea and estimate the treatment validity. However, its being rather expensive and inconvenient, alternate diagnostic tools have been proposed including wrist actigraphy. So far, actigraphies have been adopted usefully to field-survey sleep apnea prevalence. In this study, we attempted in a sleep laboratory setting to assess the supplemental value of actigraphy in diagnosing OSAS. Methods: This study was done at the Division of Sleep Studies, the Seoul National University Hospital. Thirty-seven clinically suspected cases of OSAS underwent the one-night polysomnography, simultaneously wearing an actigraphy on non-dominant wrist. We analyzed the data of 27 polysomnographically-proven OSAS patients (male：female 20： 7；age $47.6{\pm}12.9$ years old；age range 23 to 72 years) with no other sleep disorders. We calculated RDI (respiratory disturbance index) from the polysomnography data and FI (fragmentation index) from the actigraphy data. Pearson correlation was calculated in order to compare FI with RDI and to evaluate the supplemental diagnostic value of the actigraphy. Results: Mean total sleep time on polysomnography was $401.4{\pm}57.8\;min$ (range of 274.0 to 514.1 min). Mean RDI was $21.7{\pm}20.4/hour$. Mean FI was $21.9{\pm}13.0/hour$. RDI and FI showed significant correlation (r=0.55, p<0.01). Conclusions: Wrist actigraphy in OSAS patients generates a comparable outcome to polysomnography, in measuring the nocturnal sleep fragmentation. The actigraphy could be used supplementally in inpatients, outpatients, and field survey subjects, if polysomnography is unavailable or impossible. In follow-ups related with nasal CPAP (continuous positive airway pressure), upper airway surgery, and oral appliance in OSAS patients, the actigraphy might play a more dominant role in the future.

• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.67-74
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• 2006

Introduction: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. Methods: Twelve narcoleptic patients (7 male, age: $22.9{\pm}2.6\;yrs$) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. Results: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. Discussion: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.

• Sleep Medicine and Psychophysiology
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• v.15 no.1
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• pp.25-32
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• 2008

Objectives: A few studies have compared REM sleep-dependent obstructive sleep apnea syndrome (REM-OSA) with sleep stage non-dependent apnea syndrome (SND-OSA). Despite that REM-OSA might be more common in women than men, no studies have examined the probable characteristics of women patients with obstructive sleep apnea syndrome (OSAS). This study aimed at finding out the characteristics of REM-OSA in women by comparing it with SND-OSA. Methods: Fifty-three subjects diagnosed as OSAS (AHI>5 ; AHI : apnea-hypopnea index) with nocturnal polysomnography at the Center for Sleep and Chronobiology of the Seoul National University Hospital between October 2004 and February 2006 were studied. Of them, 44 subjects with OSAS severity of mild (52 and AHI-NR<15 (AHI-R : AHI during REM sleep, AHI-NR : AHI during non-REM sleep). We compared REM-OSA group with SND-OSA as well as the criteria-determined REM-OSA cases with the visually-determined ones. Results: Among 44 subjects, 28 persons (63.6%) turned out to have REM-OSA by our criteria and 24 persons (54.5%) by visual determination. Statistically significant differences (p<0.05) were found between REM-OSA and SND-OSA groups in AHI, hypopnea index, total sleep time, total wake time, sleep efficiency index, percents of stage 1, 2 and REM sleep, and REM latency. Percent of stage REM sleep (%REM) turned out to have influence on AHI ratio (AHI-R/AHI-NR) (B=0.537, p=0.002). REM-OSA was likely to be diagnosed in milder severity of OSAS (${\chi}^2=13.117$, p<0.001) and those with higher %REM (${\chi}^2=11.325$, p=0.001). There was no significant difference between the criteria-determined and the visually-determined cases of REM-OSA. Conclusion: We suggest that REM-OSA and SND-OSA patients be differentiated in terms of pathophysiology and treatment strategies. Visual determination of REM-OSA might be useful as the screening procedure of REM-OSA. Further studies on women with OSAS and REM-OSA need to be done.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.384-389
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• 1993

Background: Pulmonary sclerosing hemangioma is rare, but still the second most common benign lung tumor, occurring most1y in middle-aged women. Methods: From January 1985 through April 1993, we experienced eight cases of solitary pulmonary sclerosing hemangioma. Results: Subjects studied were 7 female and 1 male patients. They ranged from 14 to 63 years of age(mean age, 43.8 years) at the time of operation. The patients were frequently asymptomatic and the tumor was often shown to be a large lobulated mass on radiographic examination. The tumor can usually be diagnosed on operation because of its subtle clinical and radiographic presentation. All eight cases were diagnosed intraoperatively. The mean interval between initial radiographic detection and operation was 7.9 months. Out of 8 cases, preoperative impression of benign tumor was made in 4 cases, whereas malignant tumor was suspected in the remaining 4 cases. Enucleation, wedge resection or lobectomy was performed which appropriate in each patient. Conclusion: Surgical removal of the tumor preserving as much lung parenchyma as possible is indicated for proper diagnosis and treatment of this condition.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.401-408
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• 1997

Background : Pulmonary sequestration is a rare congenital malformation, which is manifested by formation of nonfunctioning lung tissue lacking normal communication with the tracheobronchial tree. The preoperative diagnostic rate has been relatively low, and without consideration of pulmonary sequestration, unexpected bleeding from aberrant vessels may be a serious problem during the operation. The purpose of our study is to describe the clinical features of pulmonary sequestration based on a review of 15 cases treated by operation. Method : Fifteen patients with pulmonary sequestration who had undergone surgical treatment from 1991 through May 1996 at Yongdong Severance Hospital and Severance Hospital were reviewed retrospectively. Results : The mean age of the patients was 22.5 years (range 5~57), and male to female ratio was 9 : 6. Clinical presentations varied from recurrent respiratory infections such as fever, cough, and sputum or chest pain to no symptom. The chest simple X-rays showed multicystic shadow(10/15) and solid mass-like shadow(5/15). The chest CT scans, done in twelve cases, showed multicystic lesion with or without lung infiltration(8/12), solid mass-like lesion(4/12), The chest MRIs, done in three cases, revealed the aberrant arteries originating from descending aorta(2/3). Aortograms, done in four cases, showed the aberrant arteries originating from descending thoracic aorta(2/4), abdominal aorta(I/4), and intercostal artery(1/4). and the venous returns were via the pulmonary veins. Pulmonary sequestration was considered preoperatively in six patients of fifteen. Other preliminary diagnosis were lung tumor(3/15), lung abscess(21/15), bronchiectasis(2/15), and mediastinal tumor(2/15). In the operative findings, twelve cases were of intralobar type and three cases of extralobar type. The left lower lobe was most often affected(9/15) and one extralobar sequestration was in the pericardium. The aberrant arteries originated from descending thoracic aorta(6/15), abdominal aorta(1/15), internal thoracic arteries (2/15), intercostal artery(1/15), pericardiophrenic artery(1/15), but in four cases, the origins could not be defined. There was no mortality or complication postoperatively. Conclusion : In our study, preoperative diagnostic rate was relatively low, and clinical features were similar to previous reports. Preoperative vigorous diagnostic approach including aortography is strongly advocated not only for its diagnostic value, but also for accurate localization of the aberrant vessels, which is major concern to surgical procedure.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.348-358
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• 1996

Background : Interleukin-5 (IL-5) is responsible for eosinophilia in allergic diseases. In allergic bronchial asthma, there is a correlation between the extent of eosinophil infiltration in bronchial mucosa and IL-5 concentrations. In addition, IL-2 concentration is elevated in the airways and associated with eosinophilia in symptomatic patients with bronchial asthma. In animal studies, IL-2 can induce eosinophilia by increasing the synthesis of IL-5, however, it is still unknown how IL-2 can induce eosinophila in human being. The aim of this study is to evaluation the effect and mechanism of IL-2 on prolongation of eosinophil survival. Methods : After purifiing the eosinophils from the venous blood of allergic patients with eosinophilia, we measured the survival rates of eosinophils using trypan blue dye exclusion test, and the number of eosinophils with Randolp's solution. We compared the survival rates of eosinophils in the presence of IL-2 or IL-5. Neutralizing antibody for IL-5 was added in IL-2 treated eosinophils to reveal whether IL-2 induced prolongation of eosinophil survival was mediated by IL-5. We checked IL-5 m-RNA expression of lymphocytes in the presence of IL-2 by using Reverse transcription-Polymerase chain reaction (RT-PCR) method to revealed the effect of IL-2 on IL-5 m-RNA expression on lymphocyte. $\alpha$ and $\beta$ IL-2 receptors were measured on eosinophils and lymphocytes with flow-cytometer after stimulated with IL-2. Results : 1) Eosinophil survival rates increased dose dependently on IL-5 and IL-2. 2) The eosinophil survival rates increased by IL-2 were not inhibited by the pretreatment with neutralizing antibody for IL-5. 3) IL-5 m-RNA was not expressed on lymphocytes by the treatment with IL-2 up to 96 hours. 4) IL-2 upregulate the expression of IL-$2R{\alpha}$ on eosinophils, instead of no effect on the expression of IL-$2R{\beta}$. Conclusion: Interleukin-2 had the enhancing effect on the survival rates of eosinophils. The mechanism behind IL-2 induced eosinophilia might be the increment of IL-2 receptors on eosinophils rather than IL-5 synthesis by lymphocytes.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.363-371
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• 1999

Background: Because of the widespread use and availability of agricultural insecticides, acute organophosphate poisoning as a suicide or an accident is becoming the most common type of poisoning and serious problem in Korea. The mortality of organophosphate poisoning varied from 10 to 86 percent. The cause of death was thought to be a combination of excessive bronchial secretion, bronchospasm, respiratory muscle paralysis and depression of respiratory center, summarily respiratory failure. We evaluated the respiratory complications in patients with acute organophosphate intoxication to determine the predisposing, factors to respiratory failure and to reduce the incidence of respiratory failure or mortality. Method: We conducted a retrospective study of 111 patients with the discharge diagnosis of organophosphate poisoning who were hospitalized at Yenugnam University Hospital during the 5 years. The diagnosis of organophosphate poisoning has based on the followings (1) a history of exposure to an organophosphate compounds. (2) the characteristic clinical signs and symptoms. (3) decrease in the cholinesterase activity in the serum. Results: Respiratory failure developed in 31(28%) of 111 patients with acute organophosphate poisoning. All cases of respiratory failure developed within 96 hours after poisoning and within 24 hours in 23 patients. The 80 patients who did not develop respiratory failure survived. In 31 patients with respiratory failure, 15(44%) patients were dead. The patients with respiratory failure had more severe poisoning, that is, the lower level of serum cholinesterase activity on arrival, the higher mean dosage of atropine administered within first 24 hours. In 16 patients with pneumonia, 14 patients developed respiratory failure. In 5 patients with cardiovascular collapse, 2 patients developed respiratory failure. There was no correlation to between age, sex, the use of pralidoxime and respiratory failure. The serum cholinesterase level in survivors at time of respiratory failure and weaning was $66.05{\pm}85.48U/L$, $441{\pm}167.49U/L$, respectively. Conclusion: All the respiratory failure complications of acute organophosphate poisoning occurred during the first 96 hours after exposure. The severity of poisoning and pneumonia were the predisposing factors to respiratory failure. Aggressive treatment and prevention of the above factors will reduce the incidence of respiratory failure.