Clostridium difficile Infections in Children / 이화의대지

During the past decade, rates of Clostridium difficile infection (CDI) increased worldwide. Hypervirulent strains of C. difficile such as NAP1/BI/027 and PCR ribotype 078 have emerged that have changed the epidemiology of CDI. Especially, CDI rates also have increased in the community, in children previously thought to be at low risk. Recently, the use of gastric acid suppressant that facilitates intestinal transit of the bacteria and presence of inflammatory bowel disease has been reported as risk factors. Treatment for CDI usually relies on metronidazole or vancomycin, but recurrence rates remains high. New treatment options for multiple recurrence are challenging. In this article, we reviewed recent epidemiological changes, current knowledge of virulence factors, reasonable approach to the diagnosis, and optimal treatment of CDI. But, clinical guidelines for pediatric C. difficile disease have not been defined. It seems that the consensus and recommendations for managing pediatric CDI are urgently needed.

FOXP3+T Cells and TGF-beta1 in Colonic Mucosa of Children with Crohn's Disease / 대한소아소화기영양학회지

PURPOSE: Forkhead box protein 3 (FOXP3)+T cells are the major regulatory T cells controlling all aspects of the immune response. Transforming growth factor-beta (TGF-beta) is a suppressive cytokine which mediates the suppressive action of FOXP3+T cells. The aim of this study was to investigate the role of FOXP3+T cells, TGF-beta in colonic mucosa of children with Crohn's disease (CD). METHODS: Colonic mucosal biopsies were obtained from 10 children with CD (12~15 years of age) and 11 control (8~15 years of age). Frequencies of FOXP3+T, CD4+T cells and TGF-beta1 expression were examined in the lamina propria (LP) and lymphoid aggregates or follicles (LA/F) by immunohistochemistry, and later evaluated by association with disease activity. RESULTS: In the LP of CD group, frequencies of FOXP3+T, CD4+T cells, proportion of FOXP3/CD4+T cells and TGF-beta1 expression significantly increased compared to the control. In the LA/F of CD group, frequency of FOXP3+T cells, proportion of FOXP3/CD4+T cells and TGF-beta1 expression significantly increased compared to the control (p<0.05). CD4+T cells also increased compared to the control, but this finding was not significant. In the LP and LA/F of CD group, frequency of FOXP3+T cells exhibited positive correlation with CD4+T cells (p<0.05). In the LP and LA/F of CD group, TGF-beta1 expression had positive correlation with CRP, Pediatric Crohn's Disease Activity Index, and negative correlation with hematocrit and albumin (p<0.05). CONCLUSION: Increased frequency of FOXP3+T cells and TGF-beta1 expression in colonic mucosa of CD can be interpreted as a compensatory increase towards achieving down-regulation of immune responses.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity in Korean Children and Adolescents / 대한소아소화기영양학회지

PURPOSE: To evaluate the feasibility and usefulness of the waist circumference-to-height ratio (WHTR) in screening for obesity in Korean children and adolescents. METHODS: Data, including body mass index (BMI), waist circumference (WC), and height, were obtained from the national growth surveys for children and adolescents in 2005. The WHTR was calculated dividing WC by height in subjects 2~18 years of age. Overweight and obese were defined by BMI percentiles for age and gender. The receiver operating characteristic (ROC) analysis was performed to find out the optimal cutoff values of WHTR that matched BMI-determined overweight and obesity using the STATA program. The area under the curve (AUC), a measure of diagnostic power, of WHTR was compared to WC. The influence of age on WHTR was analyzed by the SAS program. RESULTS: The WHTR significantly decreased with age, and had less correlation with age in the 6~18-year-old age group than the 2~5-year-old age group. Furthermore, the WHTR also had less correlation with age than WC in the 6~18-year-old age group. The AUC of WHTR in identifying overweight and obesity was significantly higher than the AUC of WC in the 6~18-year-old age group. The optimal cutoff values were 0.51 in boys and 0.49 in girls for obesity, and 0.48 in boys and 0.47 in girls for overweight, with all having the AUC>0.9. The optimal cutoff values of WHTR had a higher sensitivity for diagnosing obesity than WC> or =90th percentiles. CONCLUSION: The WHTR is an easy, accurate, and less age-dependent index with high applicability in screening for obesity in children and adolescents.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity in Korean Children and Adolescents / 대한소아소화기영양학회지

PURPOSE: To evaluate the feasibility and usefulness of the waist circumference-to-height ratio (WHTR) in screening for obesity in Korean children and adolescents. METHODS: Data, including body mass index (BMI), waist circumference (WC), and height, were obtained from the national growth surveys for children and adolescents in 2005. The WHTR was calculated dividing WC by height in subjects 2~18 years of age. Overweight and obese were defined by BMI percentiles for age and gender. The receiver operating characteristic (ROC) analysis was performed to find out the optimal cutoff values of WHTR that matched BMI-determined overweight and obesity using the STATA program. The area under the curve (AUC), a measure of diagnostic power, of WHTR was compared to WC. The influence of age on WHTR was analyzed by the SAS program. RESULTS: The WHTR significantly decreased with age, and had less correlation with age in the 6~18-year-old age group than the 2~5-year-old age group. Furthermore, the WHTR also had less correlation with age than WC in the 6~18-year-old age group. The AUC of WHTR in identifying overweight and obesity was significantly higher than the AUC of WC in the 6~18-year-old age group. The optimal cutoff values were 0.51 in boys and 0.49 in girls for obesity, and 0.48 in boys and 0.47 in girls for overweight, with all having the AUC>0.9. The optimal cutoff values of WHTR had a higher sensitivity for diagnosing obesity than WC> or =90th percentiles. CONCLUSION: The WHTR is an easy, accurate, and less age-dependent index with high applicability in screening for obesity in children and adolescents.

Angiotensinogen gene M235T polymorphism as a predictor of cardiovascular risk in hypertensive adolescents / 소아과

PURPOSE: The renin-angiotensin system (RAS) has been demonstrated to play a major role in regulating blood pressure. Therefore, components of the RAS are likely candidate genes that may predispose an individual to essential hypertension and cardiovascular complications. Among them, the M235T polymorphism of the angiotensinogen gene has been speculated to be associated with elevated circulating angiotensinogen concentrations and essential hypertension. This study aimed to analyze the angiotensinogen M235T polymorphism in hypertensive adolescents and investigate its relationship with cardiovascular risks. METHODS: Forty Korean hypertensive adolescents (aged 16-17, systolic BP > or =140 mmHg and/or diastolic BP > or =90 mmHg) and fifty seven normal adolescents were included. Obesity index (OI), body mass index (BMI) were calculated. BP was measured by oscillometric methods in resting state. Polymerase chain reaction (PCR) technique was performed on DNA from the hypertensives subjects to analyze the M235T polymorphism. Serum homocysteine, insulin, renin, aldosterone and angiotensin converting enzyme (ACE) were tested according to each genotype. The carotid intima-media thickness (IMT) and carotid artery diameter, Pulse wave velocity (PWV) and ankle-brachial index (ABI) were measured according to each genotype. RESULTS: Genotype frequencies of T/T, M/T and M/M were 62.5%, 35.0%, 2.5%, respectively in hypertensive adolescents. The results were not significantly different compared to control group. Serum insulin, renin levels, BMI and OI were significantly higher in thoses with the M/M genotype as compared to those with the T/T of M/T genotype. CONCLUSION: This study showed that the M235T polymorphism was not associated with essential hypertension or any cardiovascular risks. Further clinical research is required to ascertain the relationship between this polymorphism and cardiovascular complications in Korean hypertensive adolescents.

Serum level of the adiponectin and adiponectin I164T polymorphism in hypertensive adolescents / 소아과

PURPOSE: Adiponectin is a molecule that plays an important role in the metabolic syndrome. In addition, its concentration is known to be decreased in obesity, type 2 diabetes, and coronary artery disease. Although a relationship between hypertension and serum adiponectin concentrations has been reported by several authors, such findings continue to be debated. We investigated whether hypoadiponectinemia is related to hypertension in adolescents and studied the associated genetic polymorphism. METHODS: Forty hypertensive adolescents (Age 16-17 years old) and twenty normotensive matched subjects were included. Serum adipo-nectin, insulin, renin, aldosterone and angiotensin converting enzyme (ACE) levels were compared. Their carotid intima-media thickness (cIMT) and pulse wave velocity (PWV) were measured. Polymorphisms of the adiponectin I164T gene were investigated using polymerase chain reaction (PCR). RESULTS: The hypertensive adolescents had significantly greater cIMT and PWV. In addition, the serum aldosterone, renin and insulin levels were significantly higher in the hypertensive group. The plasma concentrations of adiponectin did not differ significantly between the two groups. TC genotype was not found in our study subjects; they all had the TT genotype of the adiponectine gene. CONCLUSION: The results of our study showed that adiponectin levels were not significantly different in adolescents with hypertension. There was no distinctive genetic polymorphism observed in this group of patients. Further large scale studies are needed to clarify the association between genetic variations and adiponectin in hypertensive adolescents.

Leptin, adiponectin, interleukin-6 and tumor necrosis factor-alpha in obese adolescents / 소아과

PURPOSE: Obesity is associated with insulin resistance. Insulin resistance and the presence of pro-inflammatory mediators are thought to cause a state of vascular endothelial dysfunction, an abnormal lipid profile, hypertension, and vascular inflammation. These chronic inflammatory responses, which are characterized by abnormal cytokine production, lead to activation of a pro-inflammatory signaling pathway. Leptin is an important mediator of inflammatory processes and immune-mediated diseases. The purpose of this study was to investigate the relationship between leptin and various cytokines associated with obesity in adolescents. METHODS: Sixty-six obese adolescents (between 16-17 years of age, obesity index >130%) and 26 normal controls were included in this study. Obesity index and body mass index (BMI) were calculated. Serum lipid profile, AST and ALT were tested after 10 hours of fasting. Tumor necrosis factor alpha (TNF-alpha) and Interleukin-6 (IL-6) levels were measured by ELISA. Insulin, adiponectin, and leptin levels were estimated by radioimmunoassay. RESULTS: Leptin was significantly higher in the obese adolescents compared to the control adolescents (12.0+/-6.8 ng/mL vs 6.3+/-1.0 ng/mL). TNF-alpha, IL-6, and insulin were significantly higher in the obese adolescents. Adiponectin was significantly lower in the obese group than the control group (3.3+/-1.9 microgram/mL vs 5.0+/-1.4 microgram/mL). Leptin had positive correlations with obesity index, BMI, and IL-6. CONCLUSION: In obese adolescents, leptin, TNF-alpha, IL-6, and insulin might be important mediators of obesity. Further clinical research is necessary to ascertain leptin as a predictor of cardiovascular diseases and to develop a guideline for clinical intervention.