• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.271-278
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• 2008

Dialkylated phthalates have been commonly used as plasticizers and a variety of applications. Phthalate diesters have been shown to be developmental and reproductive toxicants. It is very difficult to exactly estimate the dose of dialkylated phthalates taken up by the general population because of environmental contamination. Urinary metabolites of phthalates enabled to estimate internal exposure. The objective of this study was quantitative determination of phthalate metabolites by LC/MS/MS with on-line cleanup method to analyze phthalate metabolites in Korean children's urine. We employed LC/MS/MS with on-line enrichment and column-switching techniques for this biological monitoring. Metabolites determined were 4 primary metabolites; MEHP, MnBP, MiBP, MEP and 2 secondary metabolites of DEHP; 5-OH-MEHP), 5-oxo-MEHP. We analyzed children's urine from 30 boys and 30 girls. The method detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 1.05 ng/mL for MBP, 0.22 ng/mL for MEHP, 0.15 ng/mL for 5-OHMEHP and 0.16 ng/mL for 5-oxo-MEHP, respectively. Switching Column LC/MS/MS was proven to be a useful tool to determine metabolites of phthalate diesters in human urine. The correlation among phthalate metabolites was very high and statistically significant, except MEP. The children's age (months) was negatively correlated to the concentration of phthalate metabolites. The geometric mean concentration of phthalate metabolites (mg/g creatinine) in children's urine were 25.5 for MEP, 130.3 for MnBP, 56.8 for MiBP, 19.5 for MEHP, 85.6 for 5-OH-MEHP and 83.1 for 5-oxo-MEHP, respectively. Levels of estimated daily intake of parent phthalate compounds (${\mu}g$/kg bw/day) were 0.8 for DEP, 5.0 for DnBP, 1.9 for DiBP and $8.9{\sim}14.2$ for DEHP, respectively. Estimated daily intake for DEP and DiBP were lower than those of other studies but the value for DEHP was higher than that of other study.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.22-26
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• 2014

Maple syrup urine disease (MSUD) is a disorder that involves the metabolism of branched chain amino acids, arising from a defect in branched-chain ${\alpha}$-keto acid dehydrogenase complex. Mutations have been identified in the BCKDHA, BCKDHB, or DBT genes, which encode different subunits of the BCKDH complex. Although encephalopathy and progressive neurodegeneration are its major manifestations, the severity of the disease may range from the severe classic type to milder intermediate variants. We report two Korean siblings with the milder intermediate MSUD who were diagnosed with MSUD by a combination of newborn screening tests using tandem mass spectrometry and family genetic screening for MSUD. At diagnosis, the patients' plasma levels were elevated for leucine, isoleucine, valine, and alloisoleucine, and branched-chain ${\alpha}$-keto acids and branched-chain ${\alpha}$-hydroxy acids were detected in their urine. BCKDHA, BCKDHB, and DBT analysis was performed, and two novel mutations were identified in BCKDHB. Our patients were thought to have the milder intermediate variant of MSUD, rather than the classic form. Although MSUD is a typical metabolic disease with poor prognosis, better outcomes can be expected if early diagnosis and prompt management are provided, particularly for milder forms of the disease.

• Childhood Kidney Diseases
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• v.24 no.2
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• pp.115-119
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• 2020

Distal renal tubular acidosis (dRTA) is a rare renal tubular disorder characterized by normal anion gap metabolic acidosis, hypokalemia, and high urine pH. It can be inherited or acquired. In untreated pediatric patients with dRTA, rickets and growth retardation are common. We report the case of a 12-year-old Lao girl who presented with typical clinical features of dRTA with severe bone deformities that developed after a bed-ridden state due to a bicycle accident at the age of 8 years. Initial laboratory tests revealed metabolic acidosis with a normal anion gap, hypokalemia, and alkali urine. Renal ultrasonography revealed bilateral medullary nephrocalcinosis. Whole exome sequencing revealed no pathogenic mutations. After treatment with oral alkali, potassium, and vitamin D, she could walk and run. Later, she underwent corrective orthopedic surgeries for bony deformities. Thus, in pediatric dRTA patients, despite severe symptoms remaining untreated, accurate diagnosis and proper management can improve quality of life.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.2
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• pp.31-38
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• 2023

Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder caused by a deficiency in branched chain α-keto acid dehydrogenase (BCKAD). Between 1997, when Korea's MSUD case was first reported, and 2023, 14 cases were reported in the literature. 29% of the cases experienced developmental delay, and 29% expired. The prevalence of MSUD in Korea was estimated to be 1 in 230,000. Of 21 MSUD patients currently being treated at the Korea Genetics Research Center, 19 were detected through newborn screening program, and 2 were diagnosed by the symptoms. 14 MSUD patients had confirmed genetic mutations; 6 (43%) were BCKDHA and 8 (57%) were BCKDHB. In one case, a large deletion was observed. 4 patients had leucine levels above 2,000 (umo/L), and post-dialysis diet therapy was initiated in the newborn period. No patient required further dialysis as diet therapy and regular monitoring proved highly effective. Most MSUD patients were growing normally; weight and height growth were above the 50th percentile in 76% of the cases while BMI values were higher than normal in 71% of cases. Developmental delays were observed only in 2 cases (10%) and anticonvulsant use in 3 cases (14%). With newborn screening available to all Korean infants, early diagnosis and intervention should allow most patients to remain asymptomatic. However, ongoing surveillance, dietary management and continued patient compliance as well as rapid correction of acute metabolic decompensations remain critical to a favorable long-term prognosis.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.29-34
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• 2013

Urine production is vital for the removal of certain waste products produced by metabolism in the body and for the maintenance of homeostasis in the body. The kidneys produce urine by the following three precisely regulated processes: filtration, reabsorption, and secretion. Urine is composed of water, certain electrolytes, and various waste products that are filtered out of the blood through the glomeruli. The physical features of urine are evaluated carefully to detect any abnormal findings that may indicate underlying diseases in the genitourinary system. A change in urine color may indicate an underlying pathological condition, although many of the causes of abnormal urine color are benign effects of medications and foods. A characteristic and specific odor may be the result of a metabolic disease rather than a concentrated specimen or a simple urinary tract infection. Although transient changes in urine output and nocturia are usually benign conditions, persistent abnormal findings require further workup, with a thorough medical history taking. This article presents many of the conditions that physicians may encounter and will help them in the diagnosis and in establishing a treatment plan.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.32-37
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• 2022

Mucopolysaccharidosis type VI (MPS VI) is an autosomal recessive lysosomal disorder caused by the deficiency of arylsulfatase B due to mutations in the ARSB gene. Here, we report the case of a Korean female with a novel variant of MPS VI. A Korean female aged 5 years and 8 months, who is the only child of a healthy non-consanguineous Korean couple, presented at our hospital for severe short stature. She had a medical history of umbilical hernia and recurrent otitis media. Her symptoms included snoring and mouth breathing. Subtle dysmorphic features, including mild coarse face, joint contracture, hepatomegaly, and limited range of joint motion, were identified. Radiography revealed deformities, suggesting skeletal dysplasia. Growth hormone (GH) provocation tests revealed complete GH deficiency. Targeted exome sequencing revealed compound heterozygous mutations in the ARSB genes c.512G>A (p.Gly171Asp; a pathogenic variant inherited from her father) and c.1157C>T (p.Ser386Phe; a novel variant inherited from her mother in familial genetic testing). Quantitative tests revealed increased urine glycosaminoglycan (GAG) levels and decreased enzyme activity of arylsulfatase B. While on enzyme replacement therapy and GH therapy, her height increased drastically; her coarse face, joint contracture, snoring, and obstructive sleep apnea improved; urine GAG decreased; and left ventricular mass index was remarkably decreased. We report a novel variant-c.1157C>T (p.Ser386Phe)-of the ARSB gene in a patient with MPS VI; these findings will expand our knowledge of its clinical spectrum and molecular mechanisms.

• Journal of Nutrition and Health
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• v.5 no.4
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• pp.151-159
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• 1972

Protein malnutrition of children is one of the most serious nutritional deficiencies in developing country. Urea nitrogen excretion in ureotelic animals is the function most sensitive to dietary protein. The 24 hours excretion of creatinine in the urine of a given subject is remarkably constant from day to day. The creatinine excretion of different individuals of the same age and sex is also quite constant. Low ratios of urinary urea to creatinine are found children low protein intake. The foregiving world-wide investigations indicate that the urea nitrogen/creatinine ratios seems to be a good biochemical indicator to distinguish among group with different levels of protein intake. The purpose of this study is to evluate an indicator of protein intake on the elementary school children ranged from 6 to 8 years of age living in rural and urban areas. Each child measured for height and weight of body. weight measured by means of a plate from scale and height by a vertical measuring rod. Biochemical test were taken from a finger-tip and urine. Hemoglobin level in the blood was measured by cyanomethemoglobin method. From the urine samples, urea nitrogen and urea creatinie were determined by Folin-Wu method and: calculate the ratio. The following result were obtained: 1) Mean of the body weight and height in urban children(Seoul) was higher and heavier than rural children(Kyunggi, Kangwon). And 12% of boys, 18% of girls in Kyunggi and 25% of boys, 22% of girls in Kangwon area weight less than 80% of Korean Physical Standard weight level. 2) The mean hemoglobin values of boys and girls in Seoul are children were 13. 3g/100ml, 13.1g/100ml and the mean of hemoglobin values in Kyunggi 12.9g/100ml of boys, 12.4g/100ml of girls, and 12.4g/100ml of boys, 12.9g/100ml of girls in Kangwon children. It is found that 22% to 24% children inrural area (Kyunggi, Kangwon) had hemoglobin level less than 12g/100ml which means anemia. 3) The mean of hematocrit level of Seoul, boys and girls children were 33.5%, 34.1% and 33.4%, 33.1%, in Kyunggi area and 33.1%, 32.9% in Kangwon area. 4) Urea nitrogen/creatinine ratios in Seoul children were 9. 0, 10. 0 of boys and girls, the ratio were 8.2, 8.0 in Kyunggi boys and girls children, and 7.5 and 7.4 in Kangwon boys, girls children. Low-income rural and upper-income urban background large differences between two groups in the urea nitrogen/creatinine ratio(Seoul: Kangwon in male, female children. p<0.05, p<0.001). The urea nitrogen/creatinine ratio definetly seems to be a good indicator of the quantity of the protein intake. However, whether or not it is an indicator of the quality of the ingested protein ramains to be seen.

• Journal of Environmental Health Sciences
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• v.41 no.4
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• pp.231-240
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• 2015

Objectives: Blood mercury levels among adults living in certain areas of the Gyeongsang Provinces have been shown to be very high (Kunwee County $29.6{\mu}g/L$, Yeongcheon-city $26.7{\mu}g/L$). The purpose of this project was to determine mercury exposure levels in schoolchildren and factors related with their mercury levels in high mercury exposure areas identifyed by the 2007 Korea National Environmental Health Survey. Methods: From June to September 2010, 1,097 students from grades 3 to 6 at 19 elementary schools participated in this study, including 294 students from 10 elementary schools in Kunwee County, 529 students from Yeongcheon City, 122 students from two elementary schools in Pohang City, North Gyeongsang Province, and 152 students from two elementary schools in Ulsan Metropolitan City. Biological samples from schoolchildren, including whole blood, urine and hair, were collected to measure total mercury at the time of a health check up. Information about children was collected by questionnaire. Total mercury concentrations in blood were measured using the Direct Mercury Analyzer 80 with the gold-amalgam collection method. Results: The mean mercury levels were $2.70{\mu}g/L$ in 1,091 blood samples, $2.25{\mu}g/g-creat.$ in 820 urine samples and $1.03{\mu}g/g$ in 1,064 hair samples. Blood mercury levels in the schoolchildren was slightly higher than the result of $2.4{\mu}g/L$ from a 2006 survey of elementary school children on exposure and health effects of mercury by the National Institute of Environmental Research. However, 0.3% and 4.5% of participants exceeded the reference level of blood mercury by CHBMII ($15{\mu}g/L$) and the US EPA ($5.8{\mu}g/L$), respectively. The reference level of urine by CHBMII ($20{\mu}g/L$) was exceeded by 0.4% of participants. As factors, residence period in the study areas, residence type, father's education level and income all showed significant associations with mercury level in the biological samples. The number of dental amalgam sides showed an association with urine mercury. Fish intake preference and fish intake frequency were important factors in mercury levels. In particular, intake of shark meat and recent intake of shark meat were associated with higher mercury levels. In this regard, participation in the performance of an ancestral rite showed a relation with higher mercury levels. Conclusion: The intake of shark meat was very important factor to high mercury exposure level. It is recommended to monitor and manage students with high mercury exposures who exceeded CHBM II and EPA guidelines, and include blood mercury testing in the Children's Health check up for this province.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.339-347
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• 2018

Acute kidney injury (AKI) is characterized by abrupt deterioration of renal function, and its diagnosis relies on creatinine measurements and urine output. AKI is associated with higher morbidity and mortality, and is a risk factor for development of chronic kidney disease. There is no proven medication for AKI. Therefore, prevention and early detection are important. Physicians should be aware of the risk factors for AKI and should monitor renal function in high-risk patients. Management of AKI includes optimization of volume status and renal perfusion, avoidance of nephrotoxic agents, and sufficient nutritional support. Continuous renal replacement therapy is widely available for critically ill children, and this review provides basic information regarding this therapy. Long-term follow-up of patients with AKI for renal function, blood pressure, and proteinuria is recommended.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.89-93
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• 2017

Purpose: Virus-associated rhabdomyolysis is very rare. We report 15 patients with rhabdomyolysis caused by various viruses. Methods: Fifteen patients who were diagnosed with rhabdomyolysis and a viral infection were included in this study. Clinical, laboratory, and radiologic findings were evaluated through retrospective chart reviews. Results: Chief complaints were severe bilateral lower leg pain and leg weakness. The median age was 5.7 years. The male:female ratio was 2:5. The viral infections were caused by influenza virus B, parainfluenza virus, and rhinovirus. One patient with influenza virus B had coinfection with coronavirus. Median initial laboratory values and ranges were as follows: serum creatinine, 0.4 (0.1-0.5) mg/dL; serum aspartate transaminase, 124 (48-1,098) IU/L; serum alanine transaminase, 30 (16- 1,455) IU/L; serum creatine kinase, 2,965 (672-16,594) IU; serum lactate dehydrogenase, 400 (269-7,394) IU/L; serum myoglobin, 644 (314-3,867) ng/mL; urine myoglobin, 3 (3-10,431) ng/mL. All patients recovered without complications. Conclusion: This is the first report of the simultaneous occurrence of rhabdomyolysis caused by various viruses. This is also the first report of rhinovirus-associated rhabdomyolysis.