• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.609-622
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• 1997

Nitrogen dioxide $(NO_2)$ has been regarded as one of the main elements among air pollutants, and we measured $NO_2$ levels of near gas range, kitchen, living room and outdoor on 489 apartments in Pusan area. $NO_2$ were sampled by using Palmes tubes (diffusion tube sampler) during August 16-25, 1995 (summer) and January 15-29, 1996 (winter), respectively. Authors wanted to know comparison of $NO_2$ levels in summer and winter, $NO_2$ levels categorized by variables, and variables affected to $NO_2$ levels. According to this study, we conducted to establish the degree of indoor-outdoor air pollution of urban apartments in Korea and methods to reduce indoor air pollution. The results of this study were summarized as follows: 1) Mean $NO_2$ levels of near gas range, kitchen, living room, and outdoor were $25.9{\pm}10.0ppb,\;23.3{\pm}8.0ppb,\;19.9{\pm}6.1ppb,\;and\;19.0{\pm}6.0ppb$ in summer, and $34.5{\pm}16.8ppb,\;28.2{\pm}13.4ppb,\;25.3{\pm}12.5ppb,\;21.8{\pm}9.8ppb$ in winter, respectively. 2) Mean $NO_2$ levels according to the floor levels were not significantly different in summer, and in winter, $NO_2$ levels were decreased as the floor levels were increasing, but those were increased above 16th floor. 3) Variables showing significant correlation(p<0.05) with $NO_2$ levels were as follows; Summer: floor level, family size, number of family during a meal, number using gas range during rice cooking per day, and natural ventilation. Winter: floor level, family size, number of person who have been respiratory disease in a house, number of family during a meal, total number of meals, and number using gas range during rice or side-dish cooking per day. 4) We suggest that the methods of reducing indoor $NO_2$ levels are ventilation during cooking, complete combustion, decreasing number and time of cooking, and substitution of fuels.

• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.801-814
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• 1996

Background: Korean people could abuse healthy foods as well as medications, which might cause serious side effects. The aim of this study was elucidating liver dysfunction due to the self-medications of hepatotonics, healthy foods and herb medications by nested case-control study. Methods: Study subjects were drawn from male members of Seoul Cohort Study who were recruited by self-administered structured questionnaire survey through mailing to the healthy men between the age of 40 and 59 years through the program of biennial health check-up offered by Korea Medical Insurance Corporation(KMIC). The liver dysfunction was defined as the level of serum AST and ALT above 40 IU/L and increased in more than one hunderd per-cent during the 2 year follow-up period. To estimate the odds ratio between self-medication and liver dysfunction after controlling for potential confounders, logistic regression was performed. Results: During the follow-up period, 30 members were identified to fit into case criteria and 2,625 members were selected as control. In logistic regression analyses, history of healthy foods intake, age under 45 years, obesity, and habit of regular exercise were significantly associated with liver dysfunction. The following factors exhibited no statistical significance: intake of hepatotonics, of herb medicine; history of disease in family, of operation, and of radiologic examination; smoking habits and drinking amounts. Conclusion: The significant association between the intake of healthy foods and the liver dysfunction illustrates that chronically optional overuse of healthy foods might bring to hazards to health. As the increasing trend of the size of purchasing healthy foods in Korea, pharmacoepidemiologic studies evaluating the safety and efficacy of the widely used healthy foods should be performed in the near future.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.508-517
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• 1997

Hepatitis B virus(HBV) infection is one of the major health problems in Korea and HBsAg positive rate was known to be about $5\sim15%$ in general population. This study was conducted to identify the positive rates of serum HBsAg and anti-HBs among community population regarded as having hish HBV vaccination rate than in previous decade, using EIA(Enzyme immunoassay) method, in Seo-Gu, Taegu, Korea. The study subjects were 1,160 who visited Seo-Gu Health Center for check-up serologic markers of hepatitis 3. The data were obtained from the serologic test for hepatitis markers and questionnaire survey was conducted to obtain the general characteristics, vaccination history, past history of hepatitis and other liver disease, and exposure history to risk factors of hepatitis of the study subjects. The positive rates of HBsAg and anti-HBs were 5.2% and 62.4% respectively. The positive rates of HBsAg for male and female were 6.6% and 4.3% respectively. The age was divided into two groups as group I (less than 15 years old), group II (more than 16 years old) according to the hypothesis that these two groups might be different in HBV vaccination rate. HBV vaccination rates for group I and II were 83.1% and 52.3%. The positive rates of HBsAg for group I and II were 2.6% and 6.5%. The positive rates of HBsAg for the vaccinated people of the group I and II were 2.2% and 3.5%, the positive rates of anti-HBs for the vaccinated people of the group I and II were 70.1% and 71.1% respectively. The most significant factor in positive rate of HBsAg was 'hepatitis carrier in family'. Multiple logistic regression analysis revealed that 'hepatitis history' and 'hepatitis carrier in family' were significant variables for positivity of HBsAg, and 'hepatitis B vaccination' was only a significant variable for positivity of anti-HBs.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.46-55
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• 2005

Purpose : Recurrent urinary tract Infection(UTI) in primary vesicoureteral reflux(VUR) may lead to serious renal scarring, a major cause of childhood hypertension and end-stage renal disease. To prevent recurrent UTI, low-dose long--term antibiotic prophylaxis has been recommended. However, recurrent UTI still develops during antibiotic prophylaxis, the efficacy of which is now being disputed. The emergence of resistant bacteria has also raised concerns. To evaluate the effect of antibiotic prophylaxis, we investigated recurrent UTI during prophylactic antibiotic use in children with primary VUR Materials : The incidence and risk factors of recurrent UTI were retrospectively evaluated in ninety-one children with primary VUR on trimethoprim- sulfamethoxazole(TMP/SMX) prophylafis during the year following their index febri]e UTI. Results : Recurrent UTI occurred in 31.9%(29/91) children and comprised 0.32 episodes/patient year. Febrile UTI was 0.26 episode/patient year and afebrile UTI was 0.07 episodes/patient year. The recurrent rate of UTI in male patients with phimosis was 37.2%(19/51), which was significantly higher than in males without phimosis 0%(0/5)(P=0.025). In the logistic regression analysis for recurrent UTI, renal scar was the significant risk factor for recurrent UTI [RR 3.8(95% CI 1.0-14.1) P=0.04]. For other well-known risk factors such as sex, age, degree of VUR, APN, and voiding dysfunction, the differences were not significant. Conclusion : TMP/SMX prophylaxis did not prevent recurrent UTI in children with primary VUR. Phimosis and renal scars were the risk factors for recurrent UTI but the grade of primary VUR was not. In VUR without phlmosis and renal scar, a randomized controlled study without antibiotic prophylaxis is required. (J Korean Soc Pediatr Nephrol 2005;9:46-55)

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.56-63
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• 2005

Purpose : Development of renal scarring is associated with delayed diagnosis and treatment of urinary tract infection(UTI). This study was performed to clarify how soon treatment should be started to Inhibit renal scarring after onset of UTI and the factors associated with renal scarring in children with a first episode of febrile UTI. Methods : We retrospectively reviewed 163 patients with a first episode of febrile UTI under the age of 2 years from April 2000 to Ap,il 2004. All patients had a DMSA renal scan and voiding cystourethrogram done in the diagnostic period, 6 months after which a follow-up renal scan was done. After patients wet-e divided into 2 groups according to the duration of fever prior to start of treatment, the duration of fever after start of treatment, and total duration of fever, initial and follow-up DMSA scan findings were analyzed among the different groups. We compared the factors associated with renal scars between the groups with and without renal scars. Results : The initial DMSA renal scan identified abnormal finding in 23% of the patients who were treated $\leq$24 hr from the onset of disease and in 43% of those with fever more than 24 hr. Renal scars developed in 33% of patients who were treated $\leq$24 hr and 38% of those with fever >24 hr prior to treatment. Renal scars developed in 34% of patients with remission of fever $\leq$48 hr after treatment and ill 50% of those with fever >48 hr after treatment. The risk for renal scars was significantly higher in children who had total duration of feyer >72 hr(67%) than in those with shorter duration(19%). In children with renal scars, VUR was most highly associated with an increased risk of renal scar formation. Conclusion : Although children with a first episode of febrile UTI are treated within 24 hr after onset of the fever, renal damage cannot be prevented completely and it is mainly associated with VUR. (J Korean Soc Pediatr Nephrol 2005;9:56-63)

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.21-30
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• 2005

Purpose : Metabolic bone diseases have been mai or problems in children with renal diseases and steroid treatment is the main precipitating factor reducing bone mineral density(BMD). This study was performed to assess the prevalence of osteoporosis and to evaluate the clinical factors associated with decreased BMD in children with renal diseases. Methods : Forty-four children with renal diseases who were diagnosed at the Pediatric no phrology division of Ajou University hospital since Oct. 1994 were included. Using a new quantitative ultrasound device, BMD and the prevalence of osteoporosis were evaluated. The clinical and serological data were analyzed in association with decreased BMD. Results : A total of 44 patients were evaluated. The age at initial diagnosis was 6.7$\pm$4.2 years. At the time of evaluation, the chronological and bone age was 9.3$\pm$4.2 years and 8.2 $\pm$ 4.6 years, respectively. The renal diseases included nephrotic syndrome 24(54.5%), Henoch Schonlein purpura nephritis 7(15.9%), IgA nephropathy 6(13.9%), reflux nephropathy(RN) 2 (4.5%), and other renal disease 5(%). The prevalence of osteoporosis was 11%. There was no difference in the clinical factors between the long-term and the short-term treated steroid groups. Conclusion : The prevalence of osteoporosis was 12% in 44 children with renal diseases No significant factor was found in association with decreased BMD and there was no relationship between osteoporosis and steroid usage duration or cumulative dose. A new quantitative ultrasound, which is relatively easy to perform, especially in children, is expected to be in common use and will enable clinicians to evaluate metabolic bone disorders with ease.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.150-156
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• 2003

Purpose : Efforts to predict the clinicopathological outcome of IgA nephropathy have been made but have yielded conflicting results and have not helped in deciding the appropriate timing of the renal biopsy. In this study, we reviewed the predictive factors of clinicopathological outcome for finding out the criteria of renal biopsy timing of IgA nephropathy. Methods : Forty children diagnosed with biopsy proven IgA nephropathy at Wonju Christian Hospital were studied retrospectively, based on medical records. Results : Among 39 patients, 2 children progressed to higher serum creatinine level. One of them reached to the end stage renal disease within 2 year 7 months. According to WHO histopathological classification, there were 15 cases of class I, 14 cases of class II, 7 cases of class III, and 3 cases of class IV. In the mild histological classes(class I, II), gross hematuria was shown in 23 out of 29 children(P=0.02). In the severe histological classes(class III, IV), gross hematuria was noted in 4 out of 10(P>0.05). The tubulointerstitial changes were grade 1 in 24 cases, grade 2 in 4 cases, grade 3 in 8 cases, and grade 4 in 3 cases. With an increase in the tubulointerstitial grade, the 24 hour urine protein/albumin ratio increased. Serum creatinine less than 0.79 mg/dL could predict the lower grade(grade 1 and 2) of tubulointerstitial changes. But serum creatinine greater than 1.13 mg/dL could predict the higher grade(grade 3 and 4) of tubulointerstitial changes. In children with gross hematuria(n=27), serum creatinine was lower(0.78 vs 1.09 mg/dL, P=0.027), serum IgA was higher(316.3 vs 198.8 mg/dL), and the cases of lower WHO classification(I and II) were more common(23 vs 4, P=0.029) than the children with microscopic hematuria. Conclusion : Serum creatinine less than 0.79 mg/dL, macroscopic hematuria, and higher 24 hour urine protein/albumin ratio would predict the lower grade glomerulo tubulointerstitial lesion in IgA nephropathy and could be used as the criteria delaying the renal biopsy.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.42-50
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• 2010

Purpose : The clinical characteristics and associated anomalies in children with solitary kidney (SK) were analyzed retrospectively. Methods : Total 38 children diagnosed to have SK at our hospital between December 1989 and December 2009 were recruited, and the clinical records including imaging studies were retrospectively reviewed. SK was defined as unilateral renal agenesis by imaging studies only, and patients with regression of unilateral dysplastic kidney were excluded. Results : Among total 38 patients, 12 were male. The median age at the diagnosis of SK was 6.5 months (at birth-13 years). SK was detected by prenatal ultrasonography in 14 patients and during work-up for renal or urinary tract diseases in 13 (including urinary tract infection in 7). In 10 patients, SK was detected incidentally. Anomalies in the SK were noted in 17 patients including vesicoureteral reflux in 11. Other anomalies in the genitourinary tract were present in 16 patients, and multi-organ-involving syndromes or chromosomal anomalies were detected in 9. The mean duration of follow-up was 9 years (9 months-20 years). Two patients developed chronic renal failure during follow-up, and the median serum creatinine concentration of the remaining 36 at their last follow-up was 0.6 mg/dL. Conclusion : SK may be isolated and clinically asymptomatic; it is frequently accompanied by other anomalies in genitourinary tract and other organs, some of which can induce progressive renal dysfunction. Early recognition of associated anomalies with SK and regular follow-up is recommended to reduce long-term risk.

• Journal of Life Science
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• v.21 no.2
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• pp.300-308
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• 2011

Osteoporosis is a disease involving a decrease in bone mineral density and increased risk of fractures. Osteoblast and osteoclast activities are important for bone formation. The MC3T3-E1 osteoblastic cell line is a well-accepted model of osteogellsis in vitro. Hijikia fusiforme is a kind of edible brown seaweed that grows mainly in the Northwest Pacific region, including the countries of Korea, Japan and China, and it has been widely used as a medicinal and health food in Korea. In this study, by using osteoblasts, the effects of Hijikia fusiforme fractions on proliferation, alkaline phosphatase (ALP) activity, collagen synthesis and mineralization of cells were investigated. Hijikia fusiforme were subjected to fractionation by using hexane, methanol, butanol and aqueous. Proliferation of the MC3T3-E1 osteoblastic cells that were treated with Hijikia fusiforme fractions increased by approximately 120%. Regarding effects of Hijikia fusiforme fractions on ALP activity, 1 ${\mu}g$/ml butanol fraction showed the highest activity. The synthesis of collagen increased significantly in response to treatment with Hijikia fusiforme fractions, with the exception of the hexane fraction. Moreover, mineralization in the MC3T3-E1 cells that were treated with 100 ${\mu}g$/ml butanol fraction increased by 281%. Also, when 100 ${\mu}g$/ml aqueous fraction was added, mineralization increased by 240%. These results indicate that Hijikia fusiforme fractions have anabolic effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.138-144
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• 2010

Purpose: Endothelial progenitor cells (EPCs), which mediates neovascularization of uterine endometrium may be involved in the neovascularization in the utero-placental circulation. Low numbers of endothelial progenitor colony-forming unit (CFU) in culture are predictive biomarker of vascular disease. The aim of the present study was to evaluate whether the number of CFU in preeclampsia differed from that in normal pregnancy. Materials and Methods: Women with singleton normal (n=26) or preeclamptic (n=20) pregnancies were studied during the third trimester. The number of EPCs was quantified by CFU methodology. Plasma levels of angiogenic factors, vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and placental growth factor (PlGF) were determined by enzyme-linked immunoassay. Results: CFU numbers were significantly decreased in the preeclamptic patients compared with the controls (median, 3; range 1-12 vs. 31; 3-81 CFU/well, P<0.001). A majority of the cells comprising individual colonies were positive for endothelial characteristics (Ulex europaeus lectin staining and acetylated low-density lipoprotein uptake). Plasma levels of the sFlt-1 were highly elevated (P<0.001) in patient with preeclampsia compared to controls, whereas PlGF were highly reduced (P=0.004), but these factors did not associate with CFU numbers. Conclusion: Our results suggest that reduced numbers of CFU obtained from maternal peripheral blood may contribute to the development of preeclampsia.