• Journal of radiological science and technology
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• v.40 no.3
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• pp.371-376
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• 2017

Since in case of children, they are sensitive to the radiation compared to the adult and the potential exposure damage lasts longer, the exposure dose should be managed better than for the adult. Therefore, this study was conducted to observe the change in the chest x-ray image by the use of grid, which eliminates the scattering rays but increases the exposure dose during the child chest x-ray examination. As a research method, SNR, CNR and V. Vuichi were measured at 100 cm and 180 cm with the grid varying the kVp to 70, 90 and 110. In addition, SNR, CNR and V. Vuichi were measured fixing 100 cm and 180cm without grid and varying the dose to 6, 8 and 10 mAs. In the results of measuring them by fixing kVp, SNR, VNR and V. Vuichi were represented high when FID is 100cm. And in the results of meaduring them varying mAs, SNR, VNR and V. Vuichi were represented high when FID is 100cm. Currently in our country, the chest x-ray examination is performed at 180 cm. However, as the image is measured high when FID is 100 cm, in case of child, FID is deemed to be 100 cm.

• Pediatric Infection and Vaccine
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• v.27 no.1
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• pp.1-10
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• 2020

A cluster of severe pneumonia of unknown etiology in Wuhan City, Hubei province in China emerged in December 2019. A novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was isolated from lower respiratory tract sample as the causative agent. The current outbreak of infections with SARS-CoV-2 is termed coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 rapidly spread into at least 114 countries and killed more than 4,000 people by March 11, 2020. WHO officially declared COVID-19 a pandemic on March 11, 2020. There have been 2 novel coronavirus outbreaks in the past 2 decades. The outbreak of severe acute respiratory syndrome (SARS) in 2002-2003 caused by SARS-CoV had a case fatality rate of around 10% (8,098 confirmed cases and 774 deaths), while Middle East respiratory syndrome (MERS) caused by MERS-CoV killed 858 people out of a total 2,499 confirmed cases between 2012 and 2019. The purpose of this review is to summarize known-to-date information about SARS-CoV-2, transmission of SARS-CoV-2, and clinical features of COVID-19.

• Childhood Kidney Diseases
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• v.4 no.2
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• pp.154-160
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• 2000

The pathogenesis of IgA nephropathy and acute poststreptococcal glomerulonephritis is not fully understood. In the past, acute poststreptococcal glumerulonephritis was the most common cause of gross hematuria in children, but now IgA nephropathy is the most common one. We experienced two cases of acute poststreptococcal glomerulonephritis superimposing to IgA nephropathy in boys Case 1 had upper respiratory infection before elevation of anti-streptolysin O, generalized edema, gross hematuria and proteinuria. The complement levels were normal. Electron microscopic findings of renal biopsy at ten days after onset showed a few big subepithelial 'humps' and localized heavy subendothelial and mesangial deposits. Immunofluoroscopic findings revealed predominant IgA deposition in the mesangium. The electron microscopic findings were diagnostic of acute poststreptococcal glomerulonephritis On the other hand, immunoflorescence microscopic findings were compatible to IgA nephropathy. In case 2, the renal biopsy which was done 2 years after onset showed only finding of IgA nephropathy. To our knowledges, there has been kw reports of acute poststreptococcal glomerulonephritis superimposing to IgA nephropathy which was confirmed by renal biopsy. We report two cases of acute poststreptococcal glomerulonephritis superimposing: to IgA nephropathy with a brief review of the literatures.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.180-185
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• 2006

Invasive Pseudomonas infections most often occur in the immunocompromised patients and are associated with high mortality rate. Rarely this disease may develop in healthy infants and children. We report two cases of invasive Pseudomonas aeruginosa infections that were diagnosed in otherwise healthy infants. The first case was a previously healthy 5-month-old infant with ecthyma gangrenosum and septicemia. She presented with fever, swelling of left periorbital area and multiple erythronodular skin lesions. Each skin lesion formed a black eschar surrounded by an erythematous areola over time. Cultures of blood, urine and discharge from skin lesions grew P. aeruginosa. On the day of visit, she showed pancytopenia which was normalized after 10 days. The patient responded well to the management with ceftazidime and tobramycin. The other case was a previously healthy 9-month-old infant with community-acquired pneumonia. He was referred from an outside hospital with fever and cough. Chest x-ray revealed pneumonic infiltrations on both lower lungs with pleural effusion on the right side. Cultures of blood and pleural fluid grew P. aeruginosa. Chest CT performed on the ninth day demonstrated pneumatoceles, lung abscess and necrosis of lung parenchyma. He was managed with ceftazidime and amikacin for 50 days. No residual pulmonary complications were noted during the three month follow-up. Laboratory results to evaluate immunologic defects of phagocytic cells, complement components and T- and B-lymphocytes were all within normal range in both patients. It should be kept in mind that Pseudomonas can be, though uncommon, a cause of community-acquired invasive infections in the previously healthy infants.

• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.55-60
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• 2012

Purpose: We conducted the immunoassay of pertussis according to ages, in order to evaluate protective immunity against pertussis in Korean populations. Methods: Healthy subjects were enrolled at four university hospitals in Korea. The subjects were grouped as seven age groups (every 10 years). Antibodies against pertussis toxin (PT) in sera were measured by enzyme linked immunosorbent assay (ELISA) kits. Geometric mean concentrations (GMC) of antibodies and the ratios of the subjects with seroprotective antibody levels were determined. The subjects with antibody titers ${\geq}24.0EU/mL$ were considered to seroprotective as the manufacturer's protocol. Results: Total 1,605 subjects (age: 2 months-65 years) participated in this study, and their GMC was $56.16{\pm}50.54EU/mL$. Among seven age groups, age group <11 year showed the highest GMC ($64.78{\pm}53.24EU/mL$) (P<0.001). In the analysis of the ratios of the subjects with seroprotective antibody titers, 68.2% of the subjects were proven to seroprotective, and age group <11 year also showed the highest ratio (76.5%) (P<0.001). Conclusions: We found that adolescences or adults (age group ${\geq}11$ year) showed lower levels of antibody against pertussis and lower ratio of the subjects with seroprotective antibody titers than children (age group <11 year).

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.132-142
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• 2010

Hypokalemia usually reflects total body potassium deficiency, but less commonly results from transcellular potassium redistribution with normal body potassium stores. The differential diagnosis of hypokalemia includes pseudohypokalemia, cellular potassium redistribution, inadequate potassium intake, excessive cutaneous or gastrointestinal potassium loss, and renal potassium wasting. To discriminate excessive renal from extrarenal potassium losses as a cause for hypokalemia, urine potassium concentration or TTKG should be measured. Decreased values are indicative of extrarenal losses or inadequate intake. In contrast, excessive renal potassium losses are expected with increased values. Renal potassium wasting with normal or low blood pressure suggests hypokalemia associated with acidosis, vomiting, tubular disorders or increased renal potassium secretion. In hypokalemia associated with hypertension, plasam renin and aldosterone should be measured to differentiated among hyperreninemic hyperaldosteronism, primary hyperaldosteronism, and mineralocorticoid excess other than aldosterone or target organ activation. Hypokalemia may manifest as weakness, seizure, myalgia, rhabdomyolysis, constipation, ileus, arrhythmia, paresthesias, etc. Therapy for hypokalemia consists of treatment of underlying disease and potassium supplementation. The evaluation of hyperkalemia is also a multistep process. The differential diagnosis of hyperkalemia includes pseudohypokalemia, redistribution, and true hyperkalemia. True hyperkalemia associated with decreased glomerular filtration rate is associated with renal failure or increased body potassium contents. When glomerular filtration rate is above 15 mL/min/$1.73m^2$, plasma renin and aldosterone must be measured to differentiate hyporeninemic hypoaldosteronism, primary aldosteronism, disturbance of aldosterone action or target organ dysfunction. Hyperkalemia can cause arrhythmia, paresthesias, fatigue, etc. Therapy for hyperkalemia consists of administration of calcium gluconate, insulin, beta2 agonist, bicarbonate, furosemide, resin and dialysis. Potassium intake must be restricted and associated drugs should be withdrawn.

• Toxicological Research
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• v.6 no.2
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• pp.205-213
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• 1990

The regulation of neurotoxicants has usually been based upon setting reference doses by dividing a no observed adverse effect level (NOAEL) by uncertainty factors that theoretically account for interspecies and intraspecies extraploation of experimental results in animals to humans. Recently, we have proposed a four-step alternative procedure which provides quantitative estimates of risk as a function of dose. The first step is to establish a mathematical relationship between a biological effect or biomarker and the dose of chemical administered. The second step is to determine the distribution (variability) of individual measurements of biological effects or their biomarkers about the dose response curve. The third step is to define an adverse or abnormal level of a biological effect or biomarker in an untreated population. The fourth and final step is to combine the information from the first three steps to estimate the risk (proportion of individuals exceeding on adverse or abnormal level of a biological effect or biomarker) as a function of dose. The primary purpose of this report is to enhance the certainty of the first step of this procedure by improving our understanding of the relationship between a biomarker and dose of administered chemical. Several factors which need to be considered include: 1) the pharmacokinetics of the parent chemical, 2) the target tissue concentrations of the parent chemical or its bioactivated proximate toxicant, 3) the uptake kinetics of the parent chemical or metabolite into the target cell(s) and/or membrane interactions, and 4) the interaction of the chemical or metabolite with presumed receptor site(s). Because these theoretical factors each contain a saturable step due to definitive amounts of required enzyme, reuptake or receptor site(s), a nonlinear, saturable dose-response curve would be predicted. In order to exemplify this process, effects of the neurotoxicant, methlenedioxymethamphetamine (MDMA), were reviewed and analyzed. Our results and those of others indicate that: 1) peak concentrations of MDMA and metabolites are ochieved in rat brain by 30 min and are negligible by 24 hr, 2) a metabolite of MDMA is probably responsible for its neurotoxic effects, and 3) pretreatment with monoamine uptake blockers prevents MDMA neurotoxicity. When data generated from rats administerde MDMA were plotted as bilolgical effect (decreases in hippocampal serotonin concentrations) versus dose, a saturation curve best described the observed relationship. These results support the hypothesis that at least one saturable step is involved in MDMA neurotoxicity. We conclude that the mathematical relationship between biological effect and dose of MDMA, the first step of our quantitative neurotoxicity risk assessment procedure, should reflect this biological model information generated from the whole of the dose-response curve.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.314-324
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• 1998

Purpose: This study was performed to evaluate the outcome of encephalo-duro-arterio-synangiosis (EDAS) surgery with rest/acetazolamide Tc-99m HMPAO SPECT in moyamoya disease. Materials and Methods: Rost/acetazolamide subtraction SPECT with consecutive acquisition were done before and 2 months after 21 EDAS surgeries in 18 patients. Perfusion decrease was graded visually for 14 areas of each hemisphere as 0 (normal) to 3 (defect) using 4 point scoring system. Postoperative rest perfusion or perfusion reserve was compared with preoperative ones. Results: Among 294 areas of 21 hemispheres, rest perfusion abnormality was found in 91 areas of 15 hemispheres. Decrease of perfusion reserve was found in 146 areas of 18 hemispheres. Six hemispheres having normal rest perfusion and 12 of 15 hemispheres having rest perfusion abnormality showed reserve decrease. Three having rest perfusion defect did not change after acetazolamide in preoperative SPECT. After operation, 16 patients (89%) demonstrated clinical improvement. Fifteen among 18 hemispheres (83%) with decreased reserve improved. Rest perfusion abnormality improved in 6 among the 15 hemispheres (40%). The areas having rest perfusion and/or reserve decrease improved in 87 among 146 areas (60%). Decrease of reserve, improved in 85% (68/80). However, areas without reserve decrease also improved in 29% (19/66). The better was preoperative rest perfusion in involved areas or the more decreased vascular reserve, the more improved perfusion and reserve after operation. Conclusion: We conclude that assessment of perfusion and Perfusion reserve using rest/acetazolamide brain perfusion SPECT predict the surgical outcome in patients with moyamoya disease.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.348-354
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• 2008

Bisphenol A (BPA), an environmental endocrine disrupter, enters the human body continuously in food and drink. Young children are likely to be more vulnerable than adults to chemical exposure due to the immaturities of their organ systems, rapid physical development, and higher ventilation, metabolic rates, and activity levels. The direct effect of BPA on peripheral tissue might also be of importance to the development of insulin resistance. However, the influence that BPA has on insulin signaling molecules in skeletal muscle has not been previously investigated. In this study, we examined the effect of BPA on fasting blood glucose (FBG) in post-weaned Wistar rats and on insulin signaling proteins in C2C12 skeletal muscle cells. Subsequently, we investigated the effects of BPA on insulin-mediated Akt phosphorylation in C2C12 myotubes. In rats, BPA treatment (0.1-1,000 ng/mL for 24 hours) resulted in the increase of FBG and plasma insulin levels, and reduced insulin-mediated Akt phosphorylation. Furthermore, the mRNA expression of insulin receptor (IR) was decreased after 24 hours of BPA treatment in C2C12 cells in a dose-dependent manner, whereas the mRNA levels of other insulin signaling proteins, including insulin receptor substrate-1 (IRS-1) and 5'-AMP-dependent protein kinase (AMPK), were unaffected. Treatment with BPA increased GLUT4 expression and protein tyrosine phosphatase 1B (PTP1B) activity in C2C12 myotubes, but not in protein levels. We conclude that exposure to BPA can induce insulin resistance by decreasing IR gene expression, which is followed by a decrease in insulin- mediated Akt activation and increased PTP1B activity.

• Health Policy and Management
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• v.18 no.3
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• pp.58-89
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• 2008

The purpose of this study was to evaluate comparatively the content of the Expanded National Immunization Program according to the provision method between 2005 and 2006 in Korea. We assessed the impact of the mutually exclusive vaccination policy using the result reports of the 2005 and 2006 Demonstration Project and the related references by the content analysis. The public health centers paid vaccination fees to the private clinic and hospital in the 2005 Demonstration Project in Daegu metropolitan city and Gunpo city. But, the public health centers directly supplied free vaccination services to the children in the 2006 Demonstration Project in Gangneung city, Yangsan city, and Yeongi-gun. The total budgets of 2005 and 2006 Demonstration Project were 6.57 billion won and 0.65 billion won, respectively. The computerized registration rates and timeliness rates of administration of each vaccination had improved all in the 5 Demonstration Project regions. However, the computerized registration rates of most vaccination in Gunpo city were higher than those in the 2006 Demonstration Project regions except hepatitis B. Especially, the computerized registration rate of BCG was 48.3%, but the BCG coverage rate by the follow-up telephone survey was 99.8% in Daegu metropolitan city. The community parents in all the regions were satisfied because of expanding financial and geographical access to immunization coverage. In conclusions, from the aspect of the main outcomes, the implementation of two different financial immunization aids appears to be widely accepted among these parents and to have had an impact on vaccination coverage. In the future, the government must try to enact that the national immunization policy including under-immunised or incompletely immunised groups would be achieved by the affordable method of the public-private dynamics.