• The Korean Journal of Physiology and Pharmacology
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• v.5 no.4
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• pp.333-342
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• 2001

Adriamycin is a commonly used chemotherapeutic agent for cancer, including acute leukemia, lymphoma, and a number of solid human tumors. However, recent studies have recognized severe cardiotoxicity after an acute dose, which are likely the result of generation of free radicals and lipid peroxidation. Therefore, the clinical uses of adriamycin have been limited. Melatonin, the pineal gland hormone known for its ability to modulate circardian rhythm, has recently been studied in its several functions, including cancer growth inhibition, stimulating the immune system, and acting as an antioxidant and radical scavenging effects. In the present study, we evaluated the effect of melatonin administration on adriamycin-induced cardiotoxicity in rat. Heart slices were prepared using a Stadie-Riggs microtome for the measurement of malondialdehyde (MDA) content used as an index of lipid peroxidation and lactate dehydrogenase (LDH) release as an indicator of lethal cell injury. Serious adriamycin-induced lethality was observed in rat by a single intraperitoneal injection in a dose-dependent manner. A single injection of adriamycin (25 mg/kg, i.p.) induced a lethality rate of 86%, with melatonin (10 mg/kg s.c. for 6 days) treatment reducing the adriamycin-induced lethality rate to 20%. The severe body weight loss caused by adriamycin was also significantly attenuated by melatonin treatment. Treatment of melatonin marked reduced adriamycin-induced the levels of MDA formation and LDH release. A cell damage indicated by the loss of myofibrils, swelling of the mitochondria as well as cytoplasmic vacuolization was seen in adriamycin-treated group. Melatonin attenuated the adriamycin-induced structural alterations. These data provide evidence that melatonin prevents adriamycin-induced cardiotoxicity and might serve as a combination with adriamycin to limit free radical-mediated cardiotoxicity.

• Journal of International Academy of Physical Therapy Research
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• v.5 no.2
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• pp.723-729
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• 2014

The purpose of this study is to understand the relationship between female college students' stress level and premenstrual syndrome so that it can provide baseline data on how to cope with the syndrome. The study subjects are 250 female college students in Gyungbook area. This study chose 199 appropriate subjects and collected data. As per general menstrual phases, this study investigated the age when one had her first period, regularity and duration of period, and amount of bleeding. It used a measurement tool to measure stress level and premenstrual syndrome. Most of the subjects experienced their first period before the age of 13. The menstrual period was irregular with the duration of less than 7 days. 123 subjects had normal amount of bleeding. 121 subjects were experiencing high level of stress over 2.4. The correlation between the level of stress and premenstrual syndrome factors showed significant static correlation for each factor. Especially, the correlation between digestive system and response of autonomic nervous system was .996 and negative emotion and behavioral change was .635, and negative emotion and pain was .614 which were relatively high. The regression analysis of factors of premenstrual syndrome depending on the subjects' stress level indicated that response of autonomic nervous system had the biggest effect in the low stress group while behavioral change, negative emotion, pain, decreased concentration, water congestion, response of autonomic nervous system, and skin change had the biggest effect in the high stress group with statistical significance. Based on the result, it can be said that higher premenstrual stress is closely related to the premenstrual syndrome one experiences for some female college students.

• Phonetics and Speech Sciences
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• v.4 no.2
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• pp.61-70
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• 2012

The current study observes the durational interaction of tautosyllabic consonants and vowels in the word-initial position of English and Korean child-directed speech (CDS). The effect of phonological laryngeal contrasts in stops on the following vowel duration, and the effect of the intrinsic vowel duration on the release duration of preceding stops in addition to the acoustic realization of the contrastive segments are explored in different prosodic contexts - phrase-initial/medial, focal accented/non-focused - in a marked speech style of CDS. A trade-off relationship between Voice Onset Time (VOT), as consonant release duration, and voicing phonation time, as vowel duration, reported from adult-to-adult speech, and patterns of durational variability are investigated in CDS of two languages with different linguistic rhythms, under systematically controlled prosodic contexts. Speech data were collected from four native English mothers and four native Korean mothers who were talking to their one-word staged infants. In addition to the acoustic measurements, the transformed delta measure is employed as a variability index of individual tokens. Results confirm the durational correlation between prevocalic consonants and following vowels. The interaction is revealed in a compensatory pattern such as longer VOTs followed by shorter vowel durations in both languages. An asymmetry is found in CV interaction in that the effect of consonant on vowel duration is greater than the VOT differences induced by the vowel. Prosodic effects are found such that the acoustic difference is enhanced between the contrastive segments under focal accent, supporting the paradigmatic strengthening effect. Positional variation, however, does not show any systematic effects on the variations of the measured acoustic quantities. Overall vowel duration and syllable duration are longer in English tokens but involve less variability across the prosodic variations. The constancy of syllable duration, therefore, is not found to be more strongly sustained in Korean CDS. The stylistic variation is discussed in relation to the listener under linguistic development in CDS.

• Journal of Korean Biological Nursing Science
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• v.23 no.3
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• pp.227-236
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• 2021

Purpose: The purpose of this study was to investigate the sleep duration, social jetlag (SJL), and subjective sleep disturbance according to the individual chronotype in rotating shift nurses. Methods: A total of 344 rotating 3-shift nurses (mean age 28.67 years) were recruited at one university affiliated hospital. They completed the following questionnaires, which were used to assess their chronotype and sleep: the morningness-eveningness questionnaire (MEQ), self-reported sleep duration of work days (SDW_shift) and free days (SDF_shift) in each shift (day [D], evening [E], night [N]), and sleep disturbance (Insomnia severity index, ISI). SJL_shift was calculated as the difference in midsleep (MS=sleep onset+1/2 sleep duration) between work days (MSW) and free days (MSF). Results: Subjects were divided into 3 chronotype groups according to the MEQ; morning (MG, 4.4%) intermediate (IG, 57.8%), and evening groups (EG, 37.8%). SDW_D was shortest (4.68 hr) and SDF_E was longest (8.93 hr) in the EG. SJL_D was longest in the EG (3.77 hr), and SJL_N was longest in the MG (7.37 hr). The prevalence of sleep disturbance was 33.3% (MG), 29.6% (IG), and 40.0% (EG), respectively, without any statistical significance. Conclusion: In order to improve the sleep of shift workers, it is recommended that the evening chronotypes should reduce the day shifts and the morning chronotypes should reduce the night shifts. We also propose a study to determine whether these shift assignments can improve the sleep in shift nurses.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.715-723
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• 2000

Background : Obstructive sleep apnea syndrome (OSAS) affects systemic blood pressure and cardiac function. The development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac rhythm, suggests that recurrent hypoxia and arousals from sleep may increase a sympathetic nervous system activity. Continuous positive airway pressure (CPAP) therapy has been found to be an effective treatment of OSAS. However, only a few studies have investigated the cardiovascular and sympathetic effects of CPAP therapy. We evaluated influences of nasal CPAP therapy on the cardiovascular system and the sympathetic activity in patients with OSAS. Methods : Thirteen patients with OSAS underwent CPAP therapy and were monitored using polysomnography, blood pressure, heart rate, presence of arrhythmia and the concentration of plasma catecholamines, before and with CPAP therapy. Results: The apnea-hypopnea index (AHI) was significant1y decreased (p<0.01) and the lowest arterial oxygen saturation level was elevated significantly after applying CPAP (p<0.01). Systolic blood pressure tended to decrease after CPAP but without statistical significance. Heart rates during sleep were not significantly different after CPAP. However, the frequency and number of types of arrhythmia decreased and sinus bradytachyarrhythmia disappeared after CPAP. Although there was no significant difference in the level of plasma epinephrine concentration, plasma norepinephrine concentration significantly decreased after CPAP (p<0.05). Conclusion : CPAP therapy decreased the apnea-hypopnea index, hypoxic episodes and plasma norepinephrine concentration. In addition, it decreased the incidence of arrhythmia and tended to decrease the systemic blood pressure. These results indicate that CPAP may play an important role in the prevention of cardiovascular complications in patients with OSAS.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.57-66
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• 2021

This study focuses on the issue of automatic severity classification of dysarthric speakers based on speech intelligibility. Speech intelligibility is a complex measure that is affected by the features of multiple speech dimensions. However, most previous studies are restricted to using features from a single speech dimension. To effectively capture the characteristics of the speech disorder, we extracted features of multiple speech dimensions: voice quality, prosody, and pronunciation. Voice quality consists of jitter, shimmer, Harmonic to Noise Ratio (HNR), number of voice breaks, and degree of voice breaks. Prosody includes speech rate (total duration, speech duration, speaking rate, articulation rate), pitch (F0 mean/std/min/max/med/25quartile/75 quartile), and rhythm (%V, deltas, Varcos, rPVIs, nPVIs). Pronunciation contains Percentage of Correct Phonemes (Percentage of Correct Consonants/Vowels/Total phonemes) and degree of vowel distortion (Vowel Space Area, Formant Centralized Ratio, Vowel Articulatory Index, F2-Ratio). Experiments were conducted using various feature combinations. The experimental results indicate that using features from all three speech dimensions gives the best result, with a 80.15 F1-score, compared to using features from just one or two speech dimensions. The result implies voice quality, prosody, and pronunciation features should all be considered in automatic severity classification of dysarthria.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.153-168
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• 1998

Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.845-853
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• 2012

To investigate the role of temperatures and photoperiods as environmental cues regulating reproductive rhythm in Pseudobagrus fulvidraco, rearing experiments were conducted using sveral rearing regimes conbined with photoperiods and water temperatures during gonadal degeneration periods. Gonadosomatic index (GSI) in control was $8.16{\pm}1.50%$, while in other experiment GSI levels in female were lower than that in the control. In case of experimental precinct of 9 light (L) and 15 L, GSI levels were decreased. But GSI level with $20^{\circ}C$ was no diffrence after 40 and 60 days. GSI level in male of control was $0.35{\pm}0.05%$. GSI under 9 L and $25^{\circ}C$ was similar to that in control, whereas its level in other experiments was lower than that in control. Testosterone (T) of female was $3.68{\pm}0.22$ ng/mL at experimental precinct. In case of 9 L and 15 L, concentration of T were lower than experimental precinct in all of water temperature. Estradiol-$17{\beta}$ ($E_2$) and $7{\alpha}$, $20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}OHP$) levels of female were $0.42{\pm}0.02$ and $0.83{\pm}0.01$ ng/mL at experimental precinct. $E_2$ levels of 9 and 15 L were higher than experimental precinct and $17{\alpha}20{\beta}OHP$ levels of 9 and 15 L were higher than experimental precinct. In case of T and 11-ketotestosterone levels were $0.69{\pm}0.11$ and $.62{\pm}0.03$ ng/mL in male. During the period of gonadal degeneration, gonadal maturation did not occur in any of the experimental regimes. However, comparatively high levels of $E_2$ observed at low temperature regimes ($20^{\circ}C$) regardless of photoperiods.

• Journal of Korean Academy of Nursing Administration
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• v.3 no.1
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• pp.119-133
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• 1997

Continuing shift service of clinical nurses can be not only the cause of occupational dissatisfaction by being connected with the change of circadian rhythm and the burden of duties to be applicable to such changes. But also of inviting the lowering of nursing quality by being affected to the resignation of the nurses as the threat to the health of the nurses. This study has selected 500 nurses at random under non-probability sampling who have been serving by shift in 7 general hospitals which have over 400 sickbeds for the purpose of cross-sectional survey design from Sep. 7 through 20, 1996. Standardized modification of the CMI has been used which was designed for Koreans with Cornell Medical Index developed by Broadman and his fellow workers as the study device. The structure of the device was composed of 35 questions on physical appeal(Chronbach's ${\alpha}=8507$) and 22 questions of mental appeal(Cronbach's ${\alpha}=.8166$ totalling 57 questions. The collected data has been computerrized by using SPSS. General character, present symptom, perceived symptom and others are sought by practical number and percentage, and the health condition comparison followed by general characters was conducted by t-test and ANOVA. The post test was by Duncan's test by the level of p<.05. 1) The items of the answer that they have the physical symptom presently by 50% or over of the nurses were as "Do you often have spells of severe dizziness", "Are your eyes often red or inflamed", "Does press or pain in the head often make like miserable", "Are your ankles often badly swollen", "Do pains in the back make it hard for you to keep up with your work". 2) The items of the answer by over 50% of the nurses as the mental symptom at present were "do you fell bad when criticized?", "Do you get angry when everything is against your will?", "do you get angry when ordered to do this and that?", "do you feel uneasy by such a trifle thing?", "do you tremble or are you freightened by sudden sound?". The mental and physical symptoms which have appeared presently in connection with the shift service have been agreed with each other. But the physical condition has been worse than the mental one. 3) In the physical health conditions followed by demosociological character, there were the significant differences by sex, religion and place of residence(p<.05), and in the mental health conditions, there were the significant differences by age, marital status, residence place and the required time for attending hospital(p<.05). 4) There was significant difference by the degree of satisfaction about the duty in both the physical and mental health conditions. In short, the higher the degree of duty satisfaction, the better the health conditions. 5) There were the significant difference according to the times of night duty and whether they take the drug or not or the kinds of the drugs in the physical health conditions related with the characters of night shift. Mental health conditions in the night shift case showed significant differences according to their taking drug or not or the kinds of the drugs(p<.05). I can confirm that the nurses have been affected continuously by the shift service mentally and physically. The maintenance of the physical and mental health of the nurses and its promotion are very important problem to guarantee the quality nursing in the performance of the nursing service continuously and effectively, so the hospital should make every effort to improve the duty conditions by finding out the causes affecting to their health. In the nursing management viewpoint, I think that elevating the satisfaction degree about the duty would be a great help to the promotion of physical and mental health conditions. But what is most important is that the nurses themselves should take care of themselves in maintaining the good conditions in their service in the hospital.

• Sleep Medicine and Psychophysiology
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• v.22 no.2
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• pp.64-69
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• 2015

Objectives: We investigated whether sleep behaviors, severity of insomnia and circadian typology are associated with quality of life among Gyeongsang National University (GNU) medical students. Methods: Questionnaires were distributed to 46 fourth-year students of GNU Medical School. The hospital anxiety-depression scale, insomnia severity index (ISI), morningness-eveningness questionnaire (MEQ) and WHO Quality of Life-BREF (WHOQOL-BREF) were used. Results: Quality of life in terms of physical health was associated with age, weekday total sleep time (TST), weekend TST, catch up sleep, depression, ISI score, and MEQ score. Quality of life in terms of psychological health was correlated to weekday and weekend TST, anxiety, ISI score and MEQ score. Sex, weekday TST, depression, and ISI score were revealed to influence the social aspect of quality of life, and weekday and weekend TST, and ISI score were associated with quality of life in terms of environment. Multiple regression analysis showed that better sleep quality predicted to a higher quality of life in terms of physical, psychological and environmental health, and eveningness was associated with a better quality of life in terms of physical and psychological health. Conclusion: It is concluded that physical, psychological, and environmental aspects of quality of life were associated with quality of sleep and that physical and psychological aspects of quality of life were related to eveningness in GNU medical students. Therefore, it is equally important to treat emotional problem as well as improve sleep quality.