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Dork Ro Yun 14 Articles
An Experimental Study on the Protective Effects of Ginseng Extract to Oxygen Toxicity.
Jae Young Park, Sang Il Lee, Dork Ro Yun
Korean J Prev Med. 1989;22(2):208-214.
  • 1,639 View
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AbstractAbstract PDF
The protective effects of Panax Ginseng extract to oxygen toxicity of mice were studied under 5 ATA hyperbaric oxygen atmosphere. The findings observed are as follows: 1) Administration of Ginseng water extract manifested the prolonging survival time of mice to oxygen toxicity by hyperbaric oxygen atmosphere. After 18 hours of single Ginseng water extract administration and three days, seven days of consecutive Ginseng water extract administration showed the protective effect against oxygen toxicity. 2) Three days and seven days of consecutive Ginseng water extract administration showed the more efficient protective effect than single Ginseng Water extract administration. 3) Seven days of consecutive Ginseng water extract administration did not showed the more efficient protective effect than three days of consecutive Ginseng water extract administration.
Summary
Effect of Hyperoxia on Pregnancy in the Rat.
Seung Chul Lee, Soo Hun Cho, Hyeong Sik Ahn, Dork Ro Yun
Korean J Prev Med. 1989;22(1):71-80.
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  • 22 Download
AbstractAbstract PDF
The adverse effect of diving on the fetus may extend beyond n gestational process and outcome. Primiparous Sprague-Dawley rats were assigned to one of ten exposure schedules during gestatred PO2 level, the following question about the effect of exposing a pregnant female to high partial pressure of inspired oxygen has been raised. "What effect does an increased maternal PIO2 have on fetal arterial PO2 and therefore on possible fetal oxygen poisoning?" This study was carried out to observe the effects of maternal hyperoxia on gestational process and outcome. Primiparous Sprague-Dawley rats were assigned to one of ten exposure schedules during gestation. The treatment groups were subjected to either the high concentration of oxygen, or the high atmospheric pressure. On day 21 of gestation, laparotomy was performed to examine for number and distribution of implantations and live and resorbing embryos. Fetuses were weighed, and examined for gross malformations. Subsequently, they were fixed, measured in physical parameters, and examined for visceral anomalies. Minor visceral anomalies and anatomical variation was not found. Similarily, there were no significant differences when number of resorptions, mean fetal weights, pregnancy interruption rate were compared by analysis of variance. These results indicate that exposing rats to oxygen at increased atmospheric pressure doese not affect fetal health or survival.
Summary
Effect of Hyperbaric Oxygenation on Pulmonary Superoxide Dismutase Activity in Neonatal and Adult Rats.
Hyeong Sik Ahn, Soo Hun Cho, Dork Ro Yun, Dong Ryool Lee, Yong Sik Kim
Korean J Prev Med. 1989;22(1):51-56.
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AbstractAbstract PDF
To investigate the effect of hyperbaric oxygenation on superoxide dismutase activity, neonatal rats (7-10 days old) and adult rats (approximately 100 days old) were continuously exposed to hyperbaric oxygen environment of 2.4ATA for 8 hours and their superoxide dismutase activity were measured. Neonatal rats, all survived through exposure, showed significant increases in the pulmonary superoxide dismutase activity at immediately and 24 hours after exposure. Adult rats, whose 8 hour survival rates were 14 %, did not show any significant increase in the activity of pulmonary superoxide dismutase as compared to the control adult rats. These findings are indicating that increased tolerance to oxygen toxicity in neonatal animals during exposure may be attributed to the increase in activity of superoxide dismutase in neonatal rats.
Summary
Lipid Peroxidation in Vivo Monitored as Ethane Exhalation in Hyperoxia.
Jae Cheol Song, Soo Hun Cho, Myung Hee Chung, Dork Ro Yun
Korean J Prev Med. 1987;20(2):221-227.
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AbstractAbstract PDF
In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% O2), normobaric oxygenation (NBO=1 ATA, 100% O2), hyperbaric aeration (HBA=5 ATA, 21% O2) and normobaric aeration (NBA=1 ATA, 21% O2). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<0.01). This finding supports the hypothesis that hypothesis that hyperoxia increase oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial pressure difference between the two groups.
Summary
An Experimental Study on the Efficacy of Vitamin E against Oxygen Toxicity.
Sung Gyu Lee, Sang Il Lee, Soo Hun Cho, Dork Ro Yun
Korean J Prev Med. 1986;19(2):184-192.
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AbstractAbstract PDF
Since the wide spread application of hyperbaric oxygenation in clinical setting, the problems of oxygen toxicity have been attracting a deep interest from the researchers on hyperbaric medicine as a practical issue. Among extensive research trials, the study on the protective agents against oxygen toxicity occupied one of the most challenging field. As the mechanisms of oxygen toxicity, the role of the oxygen free radicals produced by peroxidation process are strongly accepted by the leading researchers on oxygen toxicity, the probable protective effects of antioxidant against oxygen toxicity are sustaining a sufficient rationale. In this study, the author attempted to evaluate the effect of vitamin E as a protective agent against oxygen toxicity through the observation of death rate, convulsion rate, time to convulsion, and macroscopic and microscopic pathological changes of experimental rats exposed to 100% oxygen at 5 ATA for 120 minutes. The findings observed are as follows: 1) The death rate, convulsion rate, time to convulsion, organ/body weight ratio and microscopic pathological findings were identified as reliable objective and quantitative indices for oxygen toxicity. 2) Vitamin E showed excellent protective effects against CNS and pulmonary oxygen toxicity as a strong antioxidant. The most effective dose seemed to be around 400 mg/kg. 3) The results of this study are supporting the oxygen free radical hypothesis on oxygen toxicity.
Summary
Influence of Intrauterine Position on Fetal Weight in albino Rats Exposed to Carbon Monoxide.
Soo Hun Cho, Jang Seok Choi, Dork Ro Yun
Korean J Prev Med. 1986;19(1):123-129.
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AbstractAbstract PDF
Fetal weight data from 84 litters of Sprague-Dawley rats were statistically analyzed for the effect of position in the uterine horn on fetal weight. The standard score obtained from the mean weight and standard deviation of all fetuses in a uterine horn were studied for position effect. In control group, the heaviest fetus occupied the middle position with a progressive decrease in weights toward the ovarian and cervical ends of the horn. But the effect related to position for the fetal weight was not statistically significant. In contrast, rats acutely or chronically exposed to carbon monoxide showed statistically significant positional differences of fetal weight within the uterine horns. The findings that the intrauterine position effect on fetal weight which is not significant in control group may act one of confounders at the situation of transplacental toxicological studies.
Summary
A Study on the Incidence of Carbon Monoxide Poisoning.
Soo Hun Cho, Young Soo Shin, Doek Hyoung Lee, Yong Ik Kim, Dork Ro Yun
Korean J Prev Med. 1985;18(1):1-11.
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AbstractAbstract PDF
A decade ago a survey on the population-base incidence rate of anthracite coal gas(mainly carbon monoxide) poisoning in Seoul area was investigated, resulting in the incidence rate of 306/10,000 risk population and 1 death/10,000. Another survey on the carbon monoxide poisoning was investigated during 1 year period from Apr. 1983 to Mar. 1984. Total subjects of risk population were 67,740 households covering 353,287 persons. The major findings of this survey are as follows: 1. Household-base incidence rate was 8.4%; spell-base 10.4%. 2. The incidence rate was the highest in houses having each of slate roof, cement wall, vinyl floor of bedroom and direct 'ondol' heating system. 3. Average 2.1 person was attacked from one incidence of the poisoning; severity-wise person-base incidence rates per 10,000 were 352 in mild poisoning, 54 in severe poisoning and 1.4 in death-overall incidence rate 407. Several facts were identified which supported that this figure was moderately underestimated. As the incidence of the poisoning is affected by socioeconomic and environmental factors, it is natural that one expects the incidence will decrease in proportion to general improvement of the above factors. Thus the results of these two surveys seemed preposterous. But further study suggested that the incidence rate (306/10,000) decade before had been significantly underestimated and corrected-rate should have been 478/10,000 level. 4. Age and sex distribution by the degree of the poisoning was uniform with little statistical difference; overall incidence rates by sex were 339/10,000 in male and 475/10,000 in female with significant statistical difference(p<.01). 5. 5.3% of the patients were treated at hospital or local clinic; 3.0% of the patients were hospitalized. Admission rate in comatose patient(severe poisoning) was 14.2%. In conclusion, carbon monoxide poisoning remains a major health problem by now.
Summary
An Epidemiological Study on the Neurological Sequelae of Acute Carbon Monoxide Poisoning.
Byung Joo Park, Soo Hun Cho, Yoon Ok Ahn, Young Soo Shin, Dork Ro Yun
Korean J Prev Med. 1984;17(1):5-24.
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AbstractAbstract PDF
There has been an immense need for elaborate studies on the complications and the neuological sequelae generated by acute carbon monoxide (CO) poisoning which is highly prevalent in Korea due to widespread adoption of the anthracite coal briquette as domestic fuel for heating and for cooking. For this epidemiological study, a total of 444 subjects who received hospital emergency care for acute CO poisoning during the period of March 1982 February 1983 were randomly selected from the emergency patients's lists of 13 general hospitals in Seoul area. Informations on the neurological sequelae were elucidated by means of home visiting with prearranged questionnaire consisting questions and concise neurological examination. The findings obtained were summarized as follows; 1. The complications were found in 18% of the surveyed and acute decubitus was comprised 67.5% of the complications. 2. The total cumulative incidence of the neurological sequelae was 41.2 per 100 patients and the absolute incidence rate regardless of the duration after poisoning was 40.8%. 3. The incidence of the neurological sequelae was higher in the older age than in the younger and also higher in female than in male. Twice higher incidence was observed in the admitted patients than in the non-admitted patients and the incidence became higher in proportion to the duration of CO exposure, coma and admission. The poorer the consciousness level of patients found, at emergency room and at discharge, the higher the incidence. The incidence of the neurological sequelae by emergency care was higher in hyperbaric oxygen therapy group(51.9%) than in 100% O2 group(38.0%). 4. A total of five variables significantly associated with the occurrence of the neurological sequelae were selected by the stepwise discriminant analysis. The variables were following course of emergency care, age, consciousness level at discharge, admission duration, and consciousness level at emergency room in their sequence of discriminant power. Eight variables were selected as those associated with the degree of the neurological sequelae through the stepwise multiple regression analysis. Of these variables, the acute decubitus alone explained 21.1% of the total variation and all the eight variables could explain 36.5% of the same. The remaining seven variables listed in the order of their relative importance were: age, consciousness level at discharge, admission duration, coma duration and consciousness level at emergency room. 5. It was postulated that unexpectedly high incidence of the neurological sequelae of the CO poisoning in this epidemiological study was mainly due to the inadequate emergency care and the lack of efficient and sophisticated treatment measure. In the effort to minimize the incidence of grave neurological sequelae of acute CO poisoning, new guidelines for the emergency care and treatment should be pursued with efficient ways.
Summary
Hyperbaric Oxygen Treatment in Acute CO Poisoning.
Dork Ro Yun, Soo Hun Cho
Korean J Prev Med. 1983;16(1):153-156.
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AbstractAbstract PDF
No abstract available.
Summary
A Stochastic Study for the Emergency Treatment of Carbon Monoxide Poisoning in Korea.
Yong Ik Kim, Dork Ro Yun, Young Soo Shin
Korean J Prev Med. 1983;16(1):135-152.
  • 1,681 View
  • 19 Download
AbstractAbstract PDF
Emergency medical service is an important part of the health care delivery system, and the optimal allocation of resources and their efficient utilization are essentially demanded. Since these conditions are the prerequisite to prompt treatment which, in turn, will be crucial for life saving and in reducing the undesirable sequelae of the event. This study, taking the hyperbaric chamber for carbon monoxide poisoning as an example, is to develop a stochastic approach for solving the problems of optimal allocation of such emergency medical facility in Korea. The hyperbaric chamber, in Korea, is used almost exclusively for the treatment of acute carbon monoxide poisoning, most of which occur at home, since the coal briquette is used as domestic fuel by 69.6 percent of the Korean population. The annual incidence rate of comatous and fatal carbon monoxide poisoning is estimated at 45.5 per 10,000 of coal briquette-using population. It offers a serious public health problem and occupies a large portion of the emergency outpatients, especially in the winter season. The requirement of hyperbaric chambers can be calculated by setting the level of the annual queueing rate, which is here defined as the proportion of the annual number of the queued patients among the annual number of the total patients. The rate is determined by the size of the coal briquette-using population which generate a certain number of carbon monoxide poisoning patients in terms of the annual incidence rate, and the number of hyperbaric chambers per hospital to which the patients are sent, assuming that there is no referral of the patients among hospitals. The queueing occurs due to the conflicting events of the "arrival" of the patients and the "service" of the hyperbaric chambers. Here, we can assume that the length of the service time of hyperbaric chambers is fixed at sixty minutes, and the service discipline is based on "first come, first served". The arrival pattern of the carbon monoxide poisoning is relatively unique, because it usually occurs while the people are in bed. Diurnal variation of the carbon monoxide poisoning can hardly be formulated mathematically, so empirical cumulative distribution of the probability of the hourly arrival of the patients was used for Monte Carlo simulation to calculate the probability of queueing by the number of the patients per day, for the cases of one, two or three hyperbaric chambers assumed to be available per hospital. Incidence of the carbon monoxide poisoning also has strong seasonal variation, because of the four distinctive seasons in Korea. So the number of the patients per day could not be assumed to be distributed according to the Poison distribution. Testing the fitness of various distributions of rare event, it turned out to be that the daily distribution of the carbon monoxide poisoning fits well to the Polya-Eggenberger distribution. With this model, we could forecast the number of the poisonings per day by the size of the coal-briquette using population. By combining the probability of queueing by the number of patients per day, and the probability of the number of patients per day in a year, we can estimate the number of the queued patients and the number of the patients in a year by the number of hyperbaric chambers per hospital and by the size of coal briquette-using population. Setting 5 percent as the annual queueing rate, the required number of hyperbaric chambers was calculated for each province and for the whole country, in the cases of 25, 50, 75 and 100 percent of the treatment rate which stand for the rate of the patients treated by hyperbaric chambers among the patients who are to be treated. Findings of the study were as follows. 1. Probability of the number of patients per day follows Polya-Eggenberger distribution. Hourly arrival pattern of the patients turned out to be bimodal, the large peak was observed in 7:00~8:00 a.m., and the small peak in 11:00~12:00 p.m. 2. In the cases of only one or two hyperbaric chambers installed per hospital, the annual queueing rate will be at the level of more than 5 percent. Only in case of three chambers, however, the rate will reach 5 percent when the average number of the patients per day is 0.481. 3. According to the results above, a hospital equipped with three hyperbaric chambers will be able to serve 166, 485, 83, 242, 55, 495 and 41, 620 of population, when the treatment rate are 25, 50, 75 and 100 percent. 4. The required number of hyperbaric chambers are estimated at 483, 962, 1,441 and 1,923 when the treatment rate are taken as 25, 50, 75 and 100 percent. Therefore, the shortage are respectively turned out to be 312, 791, 1,270 and 1,752. The author believes that the methodology developed in this study will also be applicable to the problems of resource allocation for the other kinds of the emergency medical facilities.
Summary
Epidemiological Studies on the Acute Carbon Monoxide Poisoning.
Soo Hun Cho, Dork Ro Yun, In Dal Kim
Korean J Prev Med. 1974;7(2):359-366.
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AbstractAbstract PDF
No abstract available.
Summary
An Experimental Study on the design of the thermister thermometer.
Dork Ro Yun, Ik Su Kim
Korean J Prev Med. 1973;6(1):65-70.
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AbstractAbstract PDF
The study in the fild of medical instrument has been out of the interest by any the life scinetist in Korea. Especially the recent developments in the medical electromics are remarkable one. Authors planned this study to ascertain the possibility of setting up the thermistor thermometer with available accessories of demetic products including some specific foreign assembly parts. By proper use of the thermistor as one of the wheatstone bridge, we could detect the resistance variations due to the environmental temperature variance. The intensive care for the bridge circuit and compensation scheme was required. The calibration procedure adopted here makes it possible to read the current as the temperature. The temperature range was determined by the examination and construction of the graph of the resistance-temperature, the reduction of excessive current and self-heating of the thermistor were made. Renovation in response-velocity was under taken too. This electronic thermometer was designed and assembled by the circuitry developed in accordance with the maximum availability of domestic products with some foreign-made parts. The result of our experiment showed very stable function and proved to be the most promising item in the actual application as long as the thermistor is concerned.
Summary
A Study on the Therapeutic Effectiveness of Hyperbaric Oxygenation on Acute CO poisoning.
Dork Ro Yun, Kan Hyun Lee
Korean J Prev Med. 1972;5(1):17-23.
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AbstractAbstract PDF
Carbon Monoxide poisoning is one of the most serious Public health problems in Korea. The incidence rate officially reported has been known to be the highest in the world. This high incidence is mainly due to the wide prevalence of anthracite coal briquette as the domestic fuel for unique Korean heating system called "ondol." The coal briquette gas contains around 3-5% of Carbon Monoxide. A nation-wide effort to eliminate or reduce this serious hazards has produced little effect and the most hospitals are offering very ineffective measures such as oxygen inhalation through nasal catheter. Author has believed that this preventable accident should be approached by the secondary preventive measure because of our socio-economic status do not allow us optimistic results from primary preventive measure as far as the problem of CO poisoning is concerned. Author has treated 466 patients during 30 months period by Hyperbaric Oxygenation at Seoul National University Hospital. The results found are as follows. 1. Female has a higher incidence rate than male and the age group between 15-29 years showed highest incidence. 2. The recovery time depends on the time when the patients arrived at hospital. Earlier the arrival time, shorter the recovery time. 3. Some objective signs are representing typical physiological response to tissue hypoxia. 4. Therapeutic effectiveness of Hyperbaric Oxypenation is confirmed by such indices as recovery rate, Admission rate and average stay in hospital. Futher, these results are cocordant with other reports on the clinical value of Hyperbaric Oxygenation in the treatment of CO poisoning.
Summary
A Survey on the Environmental Conditions of the CO Patients treated by Hyperbaric Oxygen Therapy.
In Dal Kim, Dork Ro Yun, Y O Choi, I C Yun, C K Lee, Y H Yang
Korean J Prev Med. 1972;5(1):9-15.
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AbstractAbstract PDF
Carbon monoxide poisoning is one of the most serios health problems in Korea, because we have been encountered with the highest incidence of CO poisoning in the world due to the unique heating system in home called "ondal". We opened Hyperbaric chamber unit in the Seoul National University Hospital last Jan, 1969. We have treated 848 patients as of Sept. 30., 1972, around 44 months period. We collected the informations on the environmental conditions of the place where CO intoxication actually occurred by filling up the questionaire from 505 patients. The following finding were obtained. 1. Age distribution showed that the highest incidence was found in the younger age group between age of 10 to age of 29 in both sex. 2. Sex ratio of the patients was 1:1.14. 3. The socio-economic level of the patient was relatively low. 4. Housewife & housemaid were the major victims of the intoxication in the female patients & in the case of the male patient, occupational backgrounds were diverse. 5. Many patients form the middle class experienced the intoxication bu sleeping at newly built room. 6. Many intoxication has been occurred in the structure of houses where communicating doors are existing between living room & kitchen. 7. All findings obtained taught us again that CO poisoning is the serious by-product of the national fuel policy which put emphasis on the use of coal & socio-economic status is very important parameter in this hazards.
Summary

JPMPH : Journal of Preventive Medicine and Public Health