• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.148-156
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• 1992

A case-control study was conducted to investigate the relationship between blood cadmium, blood zinc and cadmium/zinc ratio and hypertension. Eighty-three hypertensive and seventy-seven normotensive study subjects matched for age and sex were selected from the workers who had no history of job-related cadmium exposure, in Ulsan city and it's vincinity, Korea. The blood cadmium in hypertensive group was $2.90{\eta}g/mL$, which was significantly higher than that of control group, $1.99{\eta}g/mL$(P<0.01). After stratifing for smoking and age variables, the relationship was still remained. The blood cadmium/zinc ratio in hypertensive group was 2.46, which was significantly higher than that of control group, 1.65(P<0.01), After stratifing for smoking and age variables, the relationship was still remained. There was no significant differance in blood zinc between hypertensive and control group. On multiple logistic regression analysis, the blood cadmium/zinc ratio is highly significant than blood cadmium. In conclusion, there is the possible relationship between blood cadmium level which has been known to be within normal limits and hypertension. But, futrher cohort studies to define the effect of cadmium on human hypertension are required.

• Archives of Plastic Surgery
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• v.35 no.6
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• pp.698-702
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• 2008

Purpose: Basal cell carcinoma is one of the most common cancers in the western population and the annual incidence rate is still on an increasing course. In Asian countries such as Korea, the incidence of basal cell carcinoma is reported to be remarkably low but is estimated to be in a steep increase nowadays. This study was to analyze the recent clinical trends of basal cell carcinoma in Korea by reviewing a single institution's experience. Methods: Throughout an 11-year period, the surgical excision of 143 cases of basal cell carcinoma was performed in our department. General data of these cases such as the primary site of cancer, age and sex of the patient, operative methods, recurrence rate were reviewed retrospectively. Results: Among the 143 patients included in this study, 82 patients were men and 61 patients were women. The ages ranged from 27 to 89 years with a mean age of 64.0 years. The head and neck region was the most frequently involved primary site for the cancer as 95.1% of the total cases occurred in this area. Especially the nose and perinasal area were the most frequent region, which was followed by the periorbital area, cheek, and perioral area. During this study period, 9 cases showed recurrence of the cancer as the overall recurrence rate was 6.3%. Conclusion: Gradual increase in the incidence of basal cell carcinoma was demonstrated in this study. Basal cell carcinoma showed high incidence in the old-age population as 68.5% of the total patients were more than 60 years of age. High recurrence rate was noted in the nasal region especially after local flap reconstruction. A more cautious approach is to be required when handing such high risk lesions. Multiple factors such as extended life span, increased outdoor leisure activity and exposure to sunlight, higher accessibility to medical services and increased understanding of the public about skin cancer are assumed to be the main reasons for this increase of basal cell carcinoma.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.829-844
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• 1997

Dentin hypersensitivity must be one of the most frequent postoperative complaints in periodontal patients. Obliterating the open dentinal tubules or decreasing the diameter of their orifices would, therefore, be an objective of treatment for hypersensitive teeth. The purpose of this study was to evaluate the effect of a pulsed Nd:YAG laser irradiation on obliteration of dentinal tubules and to determine any difference according to irradiation methods. The 45 posterior teeth that had been extracted due to periodontal disease were initially treated with tetracycline HCI(100 mg/ml, 4 min.) to remove the smear layer after root planing. The root surfaces were then irradiated by a pulsed Nd:YAG laser(EL.EN.EN060, Italy) by different laser beam spot size and different exposure condition: ${\cdot}$ group 1: irradiated group by small spot(beam diameter=1mm, lW, 2 sec) ${\cdot}$ group 2: irradiated group by large spot(beam diameter=10mm, 1W, 200 sec) ${\cdot}$ group 3: irradiated group by gradual increase of watt (from 0.3W to 1.0W), beam diameter=4mm ${\cdot}$ group 4: irradiated group by fixed watt(1.0 W), beam diameter=4mm ${\cdot}$ control group: no irradiation but root planing and tetracycline HCI conditioning only. Additionally, the specimens were retreated with tetracycline HCI(100mg/ml, 4min.) to evaluate the stability of obliteration effect by Nd:YAG laser. Specimens were examined under the scanning electron microscope(JEOL, JSM-840A, Japan). Photomicrographs were taken at ${\times}4,000$ magnification and were analyzed statistically. The results were as follows: l. Scanning electron micrographs of root surface treated by tetracycline HCI alone(control group) showed widened, funnel-shaped dentinal tubules, while those of the root surface irradiated by various methods showed partially or completely obliterated dentinal tubules and various surface alterations, eg, flat, multiple pitted, melted and resolidified surface at the same energy density. 2. There was no significant difference in the obliteration effect of dentinal tubules between group 1 and group 2, and between group 3 and group 4(p>0.05). 3. The obliteration effect of dentinal tubules by a Nd:YAG laser irradiation was relatively stable to tetracycline HCI. The results demonstrate that a pulsed Nd:YAG laser irradiation within 1.0W, regardless of irradiation methods, can obliterate dentinal tubules effectively.

• Journal of Korean society of Dental Hygiene
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• v.17 no.2
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• pp.247-258
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• 2017

Objectives: This study was conducted to identify the correlation between belief in hand hygiene, activities and related hand hygiene performance rates among dental staff. Methods: This study was based on the evaluation of 329 dental practitioners, including dental hygienists who work at dental clinics, dental hospitals, general and university dental hospitals in Seoul, Gyeonggi-do Province, and Incheon. The questionnaire consisted of a total of 46 questions, including 7 questions on general characteristics, and 25 questions on hand hygiene beliefs, and 5 questions on hand hygiene activities, and 9 questions on hand hygiene practices. This study used 291 subjects for the final analysis, excluding subjects who had provided incomplete or inappropriate responses to the questionnaire. The collected data were analyzed using an independent t-test, ANOVA, $x^2$ test, correlation analysis, and multiple linear regression analysis, where p-values of <0.05 were considered statistically significant. Results: Longer clinical career was associated with a significant increase in behavior and norm beliefs, but no sequential difference in control beliefs. The hand hygiene performance was higher in staff at larger hospitals after contact with pollutants and contaminated environments. Higher age was associated with a significant increase in hand hygiene performance rates, but profession was not statistically significant in the performance rate of hand hygiene. The hand hygiene performance rate was ranked higher among those with average work hours per week of greater than 8 hours followed by those who worked fewer than 8 hours. Fewer work hours per week, a stronger belief in hand hygiene, less frequent exposure to contaminated environments, and a greater number of hand hygiene performance had a positive effect on higher hand hygiene performance rates. Conclusions: In order to increase the hand hygiene performance rate of dental practitioners, it is considered that required time for hand washing should be ensured sufficiently. Proper usage of hand sanitizers should also be promoted efficiently.

• Journal of Preventive Medicine and Public Health
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• v.24 no.4 s.36
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• pp.516-530
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• 1991

A case-control study was conducted to investigate the effect of low-level blood lead on the blood pressure. The plasma renin activity(PRA) was measured also to investigate one of the possible mechanisms by which lead nay play a role to influence on the blood pressure. Seventy-two hypertensive and sixty -nine control study subjects were selected from the workers who had no history of b-related lead exposure, in Ulsan city and it's vicinity, Korea. In addition to measuring blood lead levels and PRA, body mass index(BMI), hematocrit, serum sodium, potassium, creatinine, ionized calcium, and cholesterol were measured. Also, the habits of smoking, alcohol drinking and family history of hypertension were checked. The blood lead level of the hypertensive group was $19.8{\pm}5.5{\mu}g/dl$, which was significantly higher than that of the control group, $12.5{\pm}4.7{\mu}g/dl$(p<0.01). On multiple logistic regression analysis, the odds ratio of blood lead level on the occurence of high blood pressure was 1.38, also statistically significant (p<0.01). There was no significant differences between the hypertensive and the control group in the PRA or In (PRA), but there was a marginally significant linear relationship between blood lead and PRA in the hypertensive group(p<0.1). In conclusion, blood lead level which has been known to be within normal limits may be one of the possible risk factors of hypertension and PRA alteration by lead may act as one of the mechanisms.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.5-24
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• 1984

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 to 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% $O_2$ 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 ana 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.

• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.77-89
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• 1981

The experimental study was undertaken to confirm the effect of vaccination of birds with Newcastle disease (ND) vaccines on the Market by use of th. various vaccination programs. Sixteen groups of birds varying from 2 to f days of age, which were originated from hyper-immunised hens against ND were immunised by three different ways, a live vaccine only, a killed vaccine only, and the combination of a live and killed vaccine according to the each schedule of employed programs. In the administration of a live vaccine only, birds were immunized by one of following methods, the combination of intranasal and intraocular inoculation, intramuscular inoculation, via drinking water and the double inoculation by spray and drinking water application. Except for the double application, all the birds were vaccinated 2,3 or 4 times with two volumes of the virus dose (drinking water application) instructed by the commercial vaccine laboratory, until 21, 28 or 30 days of age, and all the immunized birds 19, 21 or 28 days postvaccination were challenged intramuscularly with 1.0$m\ell$ of 10,000 MLD per $m\ell$ of a virulent ND virus. In the administration of the combination of a live and killed vaccine, birds were immunized 2 or 3 times intranasally at first until 14 or 28 days of age with the same dose of the above experiment of a live vaccine, and then inoculated intramuscularly 1 or 2 times until 60 days of age with 1.0 $m\ell$ of a killed vaccine. And all immunized birds 11 days postvaccination were challenged with the same procedure of the above experiment. In the administration of a killed vaccine only, birds were immunized 3 times intramuscularly until 28 days of age with varied dose (0.2-0.5 $m\ell$) of a killed vaccine and all immunized birds 33 days postvaccination were challenged with the same procedure of the above experiment. The results obtained are summerised as follows: All birds vaccinated by using the combination of a live and killed vaccine program or a killed vaccin only appeared to be refractory. without any sign of illness, to the challenge exposure with 1.0$m\ell$ of 10,000 MLD per $m\ell$ of a virulent ND virus. On the other hand, the survival rates of birds of live vaccine groups immunized by a number of vaccine program such as Salsbury's day old program, 3-3-3 program, the Institute of Veterinary Reserch program and Multiple inoculation program, were 39.58%, 43.7%, 43.75% and 47.80%, respectively. And the survival rates of birds vaccinated with a live vaccine by 4 different ways of administration, i.e., double inoculation by water and aerosol application, intramuscular injection, intranasal instillation and via 4.inking water were 87.50%, 64.06%, 42.18% and 25.00%, respectively.

• Toxicological Research
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• v.29 no.1
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• pp.53-60
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• 2013

Studies on milk transfer of drugs in non-human primates (NHPs) are among the crucial components in the assessment of peri- and postnatal toxicity because of the similarity between NHPs and humans. To evaluate the milk transfer of valproic acid (VPA) in NHPs, the toxicokinetics of VPA, an antiepileptic drug, were studied in pregnant cynomolgus monkeys. VPA was administered once daily to pregnant cynomolgus monkeys at doses of 0, 30, 90, and 270 mg/kg by oral gavage from Day 100 of gestation (GD 100) to Day 31 of lactation (LD 31). Concentrations of VPA and its metabolite, 4-ene-VPA, in the maternal plasma on GD 100, GD 140, and LD 30, and concentrations of VPA and 4-ene-VPA in the offspring plasma and milk on LDs 30 and 31, respectively, were quantified using liquid chromatography tandem mass spectrometry (LC/MS/MS). After administration of a single oral dose of VPA to pregnant monkeys on GD 100, the concentrations of VPA and 4-ene-VPA were generally quantifiable in the plasma of all treatment groups up to 24 hr after administration, which showed that VPA was absorbed and that the monkeys were systemically exposed to VPA and 4-ene-VPA. After administration of multiple doses of VPA to the monkeys, VPA was detected in the pup's plasma and in milk taken on LD 30 and LD 31, respectively, which showed that VPA was transferred via milk, and the pup was exposed to VPA. Further, the concentration of VPA in the milk increased with an increase in the dose. Extremely low concentrations of 4-ene VPA were detected in the milk and in the pup plasma. In conclusion, pregnant monkeys were exposed to VPA and 4-ene-VPA after oral administration of VPA at doses of 30, 90, and 270 mg/kg/day from GD 100 to LD 31. VPA was transferred via milk, and the VPA exposure to the pup increased with an increase in the dose of VPA. The metabolite, 4-ene VPA, was present in extremely low concentrations (< 0.5 ${\mu}g/ml$) in the milk and in the pup plasma. In this study, we established methods to confirm milk transfer in NHPs, such as mating and diagnosis of pregnancy by examining gestational sac with ultrasonography, collection of milk and pup plasma and determination of toxicokinetics, using cynomolgus monkeys.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.332-339
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• 2016

This study examined the intensity of the association of factors affecting major burns by statistical analysis for patients injured by the release of chemical hazards. A total of 446 patients were evaluated as chemical injury patients, who had visited the emergency room from 1/Jan/2010 to 31/Dec/2014. The major burn was used as a dependent variable representing the severity of chemical injury. A chi-square test (CST) and binary logistic regression test (BLRA) were used as the statistical analysis method for determining the association between major burns and the independent variables. In CST, female and their presence at an incident scene, multiple site injury were associated with major burn (p<0.05). In BLRA, the presence at an incident scene and spills (comparing explosion), discharge (comparing admission) were associated with major burns (p<0.05). In this study, the presence at an incident scene was the most significant factor concerning major burns. Furthermore, gender and injury number, exposure mechanism (spill comparing explosion), and disposition (discharge comparing admission) were also associated with major burns.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.281-288
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• 2010

Total aflatoxin ($B_1+B_2+G_1+G_2$) maximum levels of 15 ${\mu}g/kg$ ($B_1=10\;{\mu}g/kg$) were set for grain, beans, peanut, nuts & their processed food (grinding, cutting etc.), processed cereal product & processed bean product, confectionaries (peanut or nut-containing food), soybean paste, red pepper paste, dried red pepper, processed com products for popcorn and steamed rice. The maximum levels for aflatoxin $M_1$ are 0.5 ${\mu}g/kg$ for raw milk and milks before manufacturing processing. The patulin maximum level is 50 ${\mu}g/kg$ in apple juice and apple juice concentrate (including concentrate to use as raw material and converted by concentration multiple). The ochratoxin A is managed at the maximum levels of 5 ${\mu}g/kg$ in wheat, barley, rye, coffee beans and roasted coffee, 10 ${\mu}g/kg$ in instant coffee and raisin, 2 ${\mu}g/kg$ in Grape juice, concentrated grape juice as reconstituted and wine. The fumonisins ($B_1+B_2$) maximum levels are 4000 ${\mu}g/kg$ in com, 2000 ${\mu}g/kg$ in com processed food (grinding, cutting etc.) and com powder, 1000 ${\mu}g/kg$ in processed com products. Standards for mycotoxins in food have been established and the mycotoxin risk in food is managed reasonably and scientifically, based on risk assessment and exposure analysis.