• Tuberculosis and Respiratory Diseases
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• 제47권1호
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• pp.26-34
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• 1999

연구배경: 최대 산소 섭취량 ($VO_2$ max) 은 답차 운동시 자전거시 보다 높게 측정이 되는데, Hassen과 Wasserman 등에 의하면 답차 시 약 1.11배 정도 높게 측정된다고 하였다. $VO_2$ max는 나이, 성별, 키, 체중 등 뿐만 아니라 인종, 사회문화적 배경 및 운동 습관에 따라서도 영향을 받을 수 있음이 알려져 있다. 본 연구에서는 한국 대학생 연령의 성인을 대상으로 답차와 자전거 운동시 $VO_2$ max와 무산소 역치에서의 산소 섭취량 (AT)을 측정, 비교하였다. 방법: 1998 년 6월부터 9월까지 연세대학교 의과대학에 재학중인 남학생 44명을 대상 으로 하였다. 이들을 무작위로 2군으로 나누어 24명은 답차를 우선 시행 후 1주일 후 자전거로 운동을 시행하였고 20명은 자전거를 우선 시행 후 답차를 시행하였다. 증상 제한적 최대 운동 시행토록 하였으며, 최소한 호흡 교환비(RER) 가 1.1을 초과한 경우, 최대 산소 섭취량이 30초 이상 평점을 이룬 경우, 최대 운동시 심박 예비율이 15% 미만이거나 또는 호흡 예비율이 30% 미만일 경우를 최대 운동으로 정의하였고 이들 중 한가지라도 충족시키지 못한 경우에는 최대운동을 하지 않은 것으로 (submaximal exercise) 간주하여 연구에서 제외하였다. AT는 V-slope method로 구하였다. 결과: 답차 운동시의 $VO_2$ max와 AT 의 값은 각각 $45.1{\pm}6.66 m\ell$/kg/min, $26.0{\pm}6.78 m\ell$/kg/min 이었으며, 자전거 운동시에는 각각 $34.9{\pm}5.89 m\ell$/kg/min, $19.5{\pm}4.77 m\ell$/kg/min 이었다. 측정-$VO_2$ max/예측 $VO_2$ max 의 값은 답차 운동시 $98.8{\pm}13.24 %$ 이었으며, 자전거 운동시 $84.4{\pm}13.42 %$ 이었다. 자전거의 결과로 답차 운동시 $VO_2$ max 의 예측치를 구할 때 쓰이는 Hassen등의 공식을 이용하여 이를 실제 답차 운동시 얻어진 $VO_2$ max값과 비교해 보았을 때 두 값 사이의 차이는 통계적으로 유의하였다 (p<0.01). 최대 운동시 심박 예비율, 산소/맥, 호흡 예비율, $V_E$/MVV, $V_E/VCO_2$는 (답차 운동과 자전거 운동사이에 차이가 있었다 ). 그러나 $V_E/VO_2$, Vd/Vt, Ti/Ttot는 차이가 없었다. AT에서는 산소/맥, 호흡 예비율, $V_E$/MVV, Ti/Ttot값은 차이가 있었으나 나머지 값들은 그렇지 못하였다. 결론: 본 연구에서 보았듯이 답차와 자전거 사이의 차이가 크므로 결과의 해석에 이용시 유의해야 할 것이며, 향후 한국인에서 적용할 수 있는 참고치를 구하려는 노력이 필요할 것으로 여겨진다.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1376-1385
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• 2021

Foot-and-mouth disease, one of the most contagious diseases in cloven-hoofed animals, causes significant economic losses. The pathogenesis of foot-and-mouth disease virus (FMDV) infection is known to differ with age of the animals. In this study, we aimed to reveal the difference in immunological response in the initial stage of FMDV infection between piglets and adult pigs. Peripheral blood mononuclear cells (PBMCs) were isolated from 3 piglets (8 weeks old) and 3 pigs (35 weeks old) that were not vaccinated against FMDV. O-type FMDV (2 × 10² median tissue culture infectious dose) was inoculated into porcine PBMCs and the cells were incubated at 37.0℃ under 5% CO₂ for various time periods (0, 1, 3, 6, 12, 24, and 48 h). The total RNA was obtained from the FMDV-inoculated PBMCs after each time point, and the virus titer was investigated in these RNA samples. Furthermore, dynamics of mRNA expression of the six tested cytokines (interferon [IFN]-α, IFN-γ, interleukin [IL]-6, IL-8, IL-10, and tumor necrosis factor [TNF]-α) in FMDV-inoculated porcine PBMCs were evaluated by time-series analysis to determine the differences, if any, based on the age of the pigs. The PBMCs of piglets contained the highest quantity of FMDV mRNA at 6 hours post-inoculation (hpi), and the PBMCs of pigs had the highest quantity of FMDV mRNA at 3 hpi. The mean cycle threshold-value in the PBMCs steadily decreased after the peak time point in the piglets and pigs (6 and 3 hpi, respectively). The dynamics of mRNA expression of all cytokines except TNF-α showed age-dependent differences in FMDV-inoculated PBMCs. The mRNA expression of most cytokines was more pronounced in the piglets than in the pigs, implying that the immune response against FMDV showed an age-dependent difference in pigs. In conclusion, within 48 hpi, the 8-week-old piglets responded more rapidly and were more sensitive to FMDV infection than the 35-week-old pigs, which could be associated with the difference in the pathogenesis of FMDV infection among the pigs. These results provide valuable insights into the mechanisms underlying the age-dependent differences in immune response in pigs against FMDV infection.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.298-304
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• 1998

Retinoids are applied to not only cancer prevention but also cancer chemotherapy by stimulating differentiation of cells. We studied differentiation inducing effect of all-trans retinoic acid (ATRA) by studying proportion of high dense fractions of stem-like cells and the size of S phase fraction in cell cycle. From mammary organoids obtained from 7- to 8-week old F344 female rat mammary gland, we cultured rat mammary epithelial cells (RMEC) and treated physiological doses of $10^{-6}$, $10^{-7}$, and $10^{-8}$ M ATRA from the first day and then cultured for 4, 7, and 14 days. After that, immunostaining was performed using peanut agglutinin (PNA) and anti-Thy-1.1 monoclonal antibody (Thy-1.1) that can be used as markers of differentiation. We separated four different cell subpopulations by flow cytometry: cells negative to both reagents (B-), PNA-positive cells (PNA+), Thy-1.1-positive cells (Thy-1.1+), and cells positive to both reagents (B+). We observed continuous decreases of high dense fractions of stem-like cells (PNA+ subpopulations) for 14 days and as much decreases as high doses of ATRA, which were thought to be proportional to doses of ATRA. We labeled RMEC with bromodeoxyuridine and investigated cell cycle fractions that went through S phase. We observed a tendency of decrease of S phase fraction with time in culture, which, is thought to be related to continuous decreases of PNA+ subpopulations and inhibitory role of ATRA on cell cycle. These results suggest that physiological doses of ATRA could stimulate differentiation of RMEC and convert stem-like RMEC to differentiated cells in SFM for a relatively long period of 14 days.

• 한국산업보건학회지
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• 제18권3호
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• pp.224-238
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• 2008

The aim of this study is to confirm the physicochemical property and hazard of thinner (012), which is a diluent of enamel paint used for floor coating for waterproofing and oil painting for the outer wall. The literatures of physicochemical property and hazard of thinner were surveyed and its physicochemical property were evaluated. And then, the inhalation toxicity of thinner affecting the central nervous system and reproductive organs in rats were examined by subchronic (6 h./day. 5 days/ week for 13 weeks) inhalation test. 1) According to the 13-week subchronic inhalation test, there were no significant changes in clinical test and body weight. However, a significant evidence of toxicity was observed in the hematological test and organ weight such as heart, kidney, liver and brain (p<0.01) in the 200 ppm and 1,000 ppm exposure groups in a dose response manner. In the histopathology analysis, there were no significant evidence of toxicity. Therefore, thinner was not classified as an organ targeted toxic agent. In case of Harmfulness, it could be classified as a chronic toxic agent 3($500 ppm/4hr, rat). 2) The reproductive toxicity such as extension of the period of estrous cycle, reduction of serum estradiol concentration and increase of frequency of the abnormal sperm was observed in the 1,000 ppm exposed animals. 3) The result of the physicochemical property of the test material showed that the specific gravity was 0.793, boiling point $155.8^{\circ}C$, steam pressure 2.1 kPa, ignition point $34.5^{\circ}C$, and spontaneous ignition point $280^{\circ}C$. The endothermic and exothermic values were 371.4 J/g and 159.1 J/g. respectively. The explosion limit was 214 mg/l. These data showed that thinner could be classified as an explosion agent level 1.2 and ignitive liquid agent 3 ($23-60^{\circ}C$) according to the notification No. 2008-1 of the Labor Ministry, "Classifying Standard of Chemical Materials."

• 여성건강간호학회지
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• 제7권3호
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• pp.393-406
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• 2001

The purpose of this study was to find out women's need and level of knowledge about episiotomy, pain and discomfort related to episiotomy on a cross-sectional survey design. The subjects were 102 postpartal women agreed on oral consent. 34 postpartal women admitted at obstetric ward of H university hospital, 34 postpartal women admitted at 2 Sanhujoriwons, and 34 women within one year afterbirth. They were selected in Seoul, Korea. Data were collected from July, 1 to September 30, 2000, by a structured questionnaire. The instrument used for this study was a questionaire consisted of 5 items of general characteristics, 12 items of obstetric characteristics, 10 items of level of knowledge (Chronbach $\alpha$ .8176), 8 items of need of education(Chronbach $\alpha$ .8836), 3 items of pain (Chronbach $\alpha$ .9252), and 3 items of discomfort (Chronbach $\alpha$ .8092). The data were analyzed by the SPSS/PC+ program using t-test, ANOVA and Scheffe test as a post hoc and Pearson Correlation Coefficient. The results of the study were as follows; 1. 63.2% of respondents had right answer on 6-8 items among 10 items. Only 4.4% of women got right answer on 10 items all. 2. The need of education was high(4.45%) on all items and the range of score was $4.25{\sim}4.64$. 3. The strength of pain was the highest within one week afterbirth(5.93/10) and became lower in 8-14 days afterbirth(2.55). And after 15days of postpartum, the pain level became to the lowest level(1.08). However, pain was delayed until more than one month afterbirth. 4. The level of discomfort was the highest one week afterbirth(6.88/10) and became lower in 8-14 days afterbirth(4.20). And after 15days of postpartum, the discomfort level became to the lowest level(2.47). Universally, the degree of discomfort was higher than pain. 5. There was a strong positive correlation between discomforts and pain ($r=.752^{**}$) and weak positive correlation between discomforts and the level of educational need($r=.308^*$). In conclusion, women have a right to choose whether she will have episiotomy or not according to her decision making based on the comprehensive knowledge of episiotomy before they get episiotomy with consent process and explanation in detail. Women health care providers like nurses have a responsibility to do conscious raising and empowerment for women so that they could lead themselves to choose given medical treatments for women's health and wellbeing and the quality of life in her life cycle.

• Journal of Radiation Protection and Research
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• 제24권1호
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• pp.17-22
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• 1999

이온화방사선이 동물 생식세포에 미치는 생화학적 및 형태학적 영향을 알아보기 위해 본 연구를 시행하였다. 미성숙 생쥐 (ICR, 3 주령)에 $\gamma$선을 선량 $LD_{80(30)}$으로 전신조사하였다. 방사선 조사 후 6 시간, 12 시간, 1 일, 그리고 2 일 후에 난소를 적출하였다. 난소에서 추출한 과립세포의 세포주기를 DNA에 대한 유세포 분석으로 분석하였다. 세포자연사를 확인할 수 있는 $A_0$ 세포주기는 이온화방사선이 조사된 실험군에서 대조군에 비해 현저히 높은 값을 보였다. 이온화방사선을 조사한 후 6 시간 군에서 TUNEL 면역조직화학 염색도를 나타낸 난포의 수가 대조군에 비해 현저히 증가하였다. 따라서, 본 실험의 결과 방사선 조사에 의해 유발되는 난포의 퇴화는 6 시간 이내에 급성으로 진행되는 과립세포의 세포자연사에 의해 매개됨을 알 수 있었다. 유세포분석기를 이용한 세포주기 평가는 방사선에 의해 유발되는 세포자연사 기작의 이해와 퇴화난포의 정량화를 위한 수단이 될 수 있다.

• Clinical and Experimental Reproductive Medicine
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• 제25권2호
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• pp.115-122
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• 1998

The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.

• Journal of Gastric Cancer
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• 제16권3호
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• pp.177-181
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• 2016

Purpose: The International Organization for Standardization-5fluorouracil (FU) 10 trial found that bolus 5-FU and l-leucovorin was not inferior to S-1 in the treatment of gastric cancer (GC). Continuous 5-FU and the rapid injection of 5-FU have different anti-cancer effects. Thus, bolus 5-FU and l-leucovorin treatment might be useful for oral FU-resistant GC. Materials and Methods: We retrospectively analyzed the medical records of all patients with S-1 or capecitabine-resistant, unresectable, or recurrent GC treated with bolus 5-FU and l-leucovorin between January 2010 and December 2015 at Hokkaido University Hospital. The bolus 5-FU and l-leucovorin regimen consisted of intravenous l-leucovorin ($250mg/m^2/2h$) and bolus 5-FU ($600mg/m^2$) administered once weekly followed by a 2-week rest period; each cycle was repeated every 8 weeks. Results: A total of 14 patients were identified. The disease control rate was 35.7%. The median progression-free survival was 1.6 months (95% confidence interval [CI], 1.3~2.0 months), and the median overall survival was 6.3 months (95% CI, 4.7~7.9 months). No patient died from treatment-related causes. The most common severe adverse event associated with bolus 5-FU and l-leucovorin was neutropenia, which occurred in 21.4% of patients. Conclusions: Bolus 5-FU and l-leucovorin treatment might be useful for oral FU-resistant GC. We are planning a multi-center prospective phase II trial to evaluate the efficacy and safety of bolus 5-FU and l-leucovorin treatment for pre-treated unresectable or recurrent GC to confirm the results of this limited, retrospective study.

• 대한인간공학회지
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• 제22권3호
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• pp.13-26
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• 2003

The purpose of this study is to investigate the present conditions of the night work and shift work systems in the heavy chemical industrial complexes found in Changwon, Masan, and Chinhae. Korea. We will attempt to define and classify their problems; and to discover further ways to improve their systems. Fifty production factories were carefully selected as the subjects for this study. The shift systems were classified into five categories. The consecutive night shifts were long in almost all cases with 6 days (36 factories) and 7 days (13 factories). It was found that the night work of about] 2 hours continues for a long period in the weekly rotation full-day shift systems and the night-including non-full-day shift systems, and there was no holiday during a shift cycle in the continuous full-day shift systems. The work time in most shift systems was longer than the 44-hours/week permitted by Korean law. Considering the characteristics of these various types of shift systems, the most essential thing to reduce the shift workers' work load may be to shorten their working hours and improve the schedule of shift systems. It is highly recommended as a fundamental solution. to reduce the portal-to-portal hours from 12 to 8 in the night-including non-full-day shift systems and the weekly rotation full-day shift systems, and at least to employ a 4-team 3-shift system in the continuous full-day shift systems. In addition to this, it should from now on be taken as a goal to restructure the types of shift systems by taking such measures as avoiding continuous night work if possible, providing sufficient off-duty intervals both before and after night shift, providing increased opportunities for workers to nap during night work. and increasing the number of holidays.

• 한국화재소방학회논문지
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• 제34권3호
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• pp.8-17
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• 2020

본 논문은 오염물질에 따른 HFIX 절연전선 피복의 특성변화에 관한 연구이다. HFIX 절연전선 피복을 오염시키기 위해 전선의 내수성시험 항목인 KS C IEC 60811-1-3 규격을 인용, 오염물질을 선정하고 선정된 오염물질에 시료를 노출시켜 주차 별 최대 4주간 노출된 실험시료를 제작하였다. 그 후 주차 별 시료들을 대상으로 최대인장하중 및 신장률을 측정하였다. 오염노출 기간이 길어짐에 따라 최대인장하중이 상온시료의 경우 6.22%, 고온시료 6.52%, 방청윤활제 19.94% 감소하였고, 신장률 또한 급격하게 감소하여 피복 특성저하가 뚜렷하게 나타났다. 추가적인 주사전자현미경을 이용한 표면 분석결과 오염기간이 길어짐에 따라 천공, 갈라짐, 용융 등의 구조 변경 현상이 발생되어 기계적 특성이 감소되는 것으로 나타났다. 따라서 절연전선의 성능저하를 방지하기 위해 검사주기 및 보수시기의 마련이 필요할 것으로 생각된다.