Toshiki Nakanishi

Identification of AP2S1 Mutation and Effects of Low Calcium Formula in an Infant With Hypercalcemia and Hypercalciuria

CONTEXT Although AP2S1 has recently been shown to be a causative gene for familial hypocalciuric hypercalcemia type 3 (FHH3), knowledge about FHH3 remains poor. OBJECTIVE Our objective was to report AP2S1 mutation and effects of low calcium formula in a patient with hypercalcemia and hypercalciuria. PATIENT This Japanese female infant was found to have hypercalcemia by a routine laboratory test for poor weight gain on breast feeding. At 49 days of age, serum calcium (adjusted by Paynes formula) was 13.1 mg/dL, intact PTH 27 pg/mL, and urinary calcium-to-creatinine ratio 1.29 mg/mg. There was no evidence for hyperparathyroidism, PTHrP-producing neoplasm, and vitamin D excess. These data, except for hypercalciuria, appeared to be consistent with defective calcium-sensing receptor-mediated signaling. With use of low calcium formula containing 2.6 mg/dL of calcium, she showed catch-up growth, and serum calcium was decreased, as was urinary calcium-to-creatinine ratio. Furthermore, feeding with a mixture of low calcium formula and standard formula with a 2:1 ratio maintained serum calcium ∼12 mg/dL without markedly increasing serum PTH. RESULTS Although no pathologic mutation was detected in CASR or GNA11, a presumably de novo heterozygous mutation (p.Arg15Leu), a previously reported causative mutation for FHH3, was identified in AP2S1 of this patient. CONCLUSIONS The results imply that lack of hypocalciuria does not necessarily argue against the presence of AP2S1 mutations. The early infantile age of this patient would have played a certain role in the occurrence of hypercalciuria, and low calcium formula is worth attempting in infants with FHH.

Effects of maternal high-fat diet on serum lipid concentration and expression of peroxisomal proliferator-activated receptors in the early life of rat offspring.

Peroxisomal proliferator-activated receptors (PPARs) play an important role in the regulation of lipid metabolism. The aim of this study was to investigate the effects of a maternal high-fat (HF) diet on serum lipid concentration and PPAR gene expression in liver and adipose tissue in the early life of the rat offspring. Female Sprague-Dawley rats were fed either an HF or control (CON) diet 6 weeks before mating and throughout gestation and lactation. Blood and tissue samplings of male offspring were carried out at birth or weaning. Birth weights were similar and serum triglyceride (TG) and nonesterified fatty acid (NEFA) levels showed no significant difference between HF and CON newborns, despite greatly increased hepatic PPARα mRNA expression in the HF newborns (p<0.05). Both HF newborns and weanlings revealed significantly decreased hepatic PPARγ expression compared with controls (p<0.0001). Hepatic PPARα expression in the HF weanlings was reduced markedly compared with CON weanlings (p<0.0001) and showed a negative correlation with serum TG levels (r=-0.743, p<0.05). However, epididymal expression of PPARγ in the HF weanlings was upregulated significantly compared with controls (p<0.05) and demonstrated a positive correlation with epididymal fat mass (r=0.733, p<0.05). These were accompanied by obesity as well as a rise in serum TG by 79% (p<0.05) and NEFA concentration by 36% (p<0.05) in these HF weanlings. Our findings suggest that maternal HF diet leads to alterations in PPAR gene expression in the weanling offspring, which is associated with the disturbed lipid homeostasis.

Carbenoxolone Alters the Morphology of Adipose Tissues and Downregulates Genes Involved in Adipogenesis, Glucose Transport and Lipid Metabolism in High-Fat Diet-fed Mice

Glucocorticoid (GC) excess promotes adipose tissue accumulation, and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) plays an important role in the local amplification of GC. Therefore, in this study, we investigated the effects of carbenoxolone (CBX), an 11β-HSD1 inhibitor, on morphological changes in visceral fat, and the expression of genes involved in adipogenesis and lipid metabolism in high-fat (HF) diet-fed mice. Mice were fed a HF diet from 5 weeks of age. At 10 weeks of age, the mice received an intraperitoneal injection of CBX or vehicle every day for 2 weeks. CBX decreased body weight and visceral fat mass, and improved insulin sensitivity in HF-fed mice. This was accompanied by reduced adipocyte size and a decrease in large-sized adipocytes in visceral fat. The expression of adipogenesis (PPARγ and C/EBPα), glucose transport (GLUT4) and lipid metabolism (LPL, ATGL, and HSL)-related genes were suppressed in CBX mice. CBX treatment induced beneficial morphological changes in visceral fat and decreased the expression of adipogenesis, glucose transport and lipid metabolism-related genes. These findings reveal a potential mechanism underling the effects of CBX on reduced fat accumulation and improved insulin sensitivity.

Altered Gene Expressions of Ghrelin, PYY, and CCK in the Gastrointestinal Tract of the Hyperphagic Intrauterine Growth Restriction Rat Offspring

Intrauterine growth restriction (IUGR) is associated with a substantially greater incidence of metabolic syndrome in adulthood. Animal studies have shown that IUGR offspring are hyperphagic during the early postnatal period and therefore exhibit obesity. The molecular mechanisms underlying food intake regulation in the gastrointestinal tract have not been clarified in IUGR. In the present study, we utilized a rat model of IUGR by restricting the food intake of the mother (50% of the normal intake, ad libitum; FR group) from day 7 of gestation until delivery. Pups from undernourished mothers were fostered by control mothers. We examined the food intake and assessed the gene expressions of ghrelin, peptide YY (PYY), and cholecystokinin (CCK) in the alimentary tract of male newborns (postnatal day1) and adult offspring (age, 7 months). Compared to the offspring whose mothers received the standard diet ad libitum (CON offspring), FR offspring were hyperphagic from the weaning time until the end of the experiment, and resulted in a heavier final weight. Both newborn and adult FR offspring had higher ghrelin gene expression in the stomach and higher ghrelin plasma levels than did the controls. Although the gastrointestinal gene expressions and plasma levels of the anorexic peptides, PYY and CCK, were elevated in the FR newborns, they decreased in the FR adults. Our findings suggest that the altered gene expressions of orexigenic and anorexigenic gut peptides in the gastrointestinal tract in the maternal undernutrition-induced IUGR offspring provide a potential mechanism to explain hyperphagia and obesity seen in these offspring.

A case of an iliopsoas abscess in a neonate

The present study describes a male neonate with an iliopsoas abscess. He was born by Caesarean section at 35 weeks and 3 days gestation. At 24‐days‐old he had a fever and localized swelling of the groin to the femur. By ultrasonography (US) and computed tomography (CT), the swelling was diagnosed as iliopsoas abscess. We treated him through percutaneous needle drainage and antibiotics. Methicillin‐resistant Staphylococcus aureus (MRSA) was detected in the culture of the fluid from the abscess and the urine. US and CT were useful for the diagnosis and provided guidance for the needle puncture and follow‐up of the iliopsoas abscess.

The lipid fraction of human milk initiates adipocyte differentiation in 3T3-L1 cells.

BACKGROUND The prevalence of childhood obesity has increased worldwide over the past decade. Despite evidence that human milk lowers the risk of childhood obesity, the mechanism is not fully understood. AIMS We investigated the direct effect of human milk on differentiation of 3T3-L1 preadipocytes. STUDY DESIGN AND SUBJECTS 3T3-L1 preadipocytes were treated with donated human milk only or the combination of the standard hormone mixture; insulin, dexamethasone (DEX), and 3-isobututyl-1-methylxanthine (IBMX). Furthermore, the induction of preadipocyte differentiation by extracted lipids from human milk was tested in comparison to the cells treated with lipid extracts from infant formula. Adipocyte differentiation, specific genes as well as formation of lipid droplets were examined. RESULTS We clearly show that lipids present in human milk initiate 3T3-L1 preadipocyte differentiation. In contrast, this effect was not observed in response to lipids present in infant formula. The initiation of preadipocyte differentiation by human milk was enhanced by adding the adipogenic hormone, DEX or insulin. The expression of late adipocyte markers in Day 7 adipocytes that have been induced into differentiation with human milk lipid extracts was comparable to those in control cells initiated by a standard adipogenic hormone cocktail. CONCLUSIONS These results demonstrate that human milk contains bioactive lipids that can initiate preadipocyte differentiation in the absence of the standard adipogenic compounds via a unique pathway.

Dynamics of endogenous glucocorticoid secretion and its metabolism in Kawasaki disease

OBJECTIVE Kawasaki disease (KD) is a severe inflammatory disease that occurs in childhood. Recently, the initial corticosteroid therapy for KD has been reconsidered because its efficacy is controversial. The aim of this study was to evaluate the dynamic change in endogenous glucocorticoid levels and their relation with 11beta-hydroxysteroid dehydrogenase (11beta-HSD) activity in the acute phase of KD. STUDY DESIGN Sixteen KD patients were investigated. Cortisol and cortisone levels, the cortisol/cortisone ratio and C-reactive protein (CRP) levels were measured on admission, before the first intravenous immunoglobulin (IVIG) therapy and convalescence. RESULTS The 16 patients were divided into two groups. Group A included patients who received the first IVIG on admission and blood samples were collected before the first IVIG and convalescence. Group B included patients whose blood samples were collected at three different time points (on admission, before the first IVIG, and convalescence). CRP and cortisol levels and the cortisol/cortisol ratio were markedly higher before the first IVIG than those of convalescence in all patients except in one patient. In Group B patients, both serum cortisol levels and the cortisol/cortisone ratio on admission were significantly increased compared with those before the first IVIG (cortisol: p<0.005, cortisol/cortisone: p<0.001). CONCLUSIONS Decreases in cortisol levels and the cortisol/cortisone ratio before the first IVIG may be explained by a reduction in adrenal secretion and/or local glucocorticoid action through 11beta-HSD activity. These findings suggest that exogenous glucocorticoid treatment in combination with the first IVIG at the acute stage may play a synergetic role in KD.

Development of waist circumference percentiles for Japanese children and an examination of their screening utility for childhood metabolic syndrome: a population-based cross-sectional study.

BackgroundIn Japan, waist circumference (WC) percentiles to screen for childhood metabolic syndrome (MetS) are unavailable. The objectives of this study were to develop WC and WC-to-height ratio (WC/Ht) percentile curves by age and sex for Japanese children, and to test their utility in screening for MetS in children with obesity who are otherwise healthy.MethodsThe WC and WC/Ht percentiles were developed using the LMS method of summarizing growth standards, which monitors changing skewness (L), medians (M), and coefficients of variation (S) in childhood distributions. A representative dataset was used, which consisted of 3,634 boys and 3,536 girls aged 4.5–12.75 years in Shizuoka prefecture, Japan, between 2010 and 2012. Children who were obese (355 boys and 230 girls) aged 6–12 years from Osaka prefecture, Japan, were screened for childhood MetS using the new percentiles and the International Diabetes Federation’s (IDF’s) definition of MetS.ResultsThe number of participants with certain metabolic abnormalities (high systolic and diastolic blood pressure, and a high level of triglycerides) was significantly higher in boys aged 10–12 years, with a WC ≥ 90th percentile, than among those with a WC < 90th percentile. None of the participants with a WC < 90th percentile exhibited two or more metabolic abnormalities, regardless of their age or sex. Among the participants aged 10–12 years, 11.4 % of boys and 4.4 % of girls with a WC ≥ 90th percentile were diagnosed with MetS.ConclusionsThe new percentiles may have a certain level of potential to screen Japanese children for childhood MetS in accordance with the IDF definition.

Postnatal BMI changes in children with different birthweights: A trial study for detecting early predictive factors for pediatric obesity

Abstract. The purpose of this study was to clarify the degree of early postnatal growth by birthweight and detect early predictive factors for pediatric obesity. Body mass index (BMI) and degree of obesity were examined in children in the fourth year of elementary school and second year of junior high school. Their BMI at birth and three years of age were also examined. Based on birthweight, participants were divided into three groups: low (< 2500 g), middle (2500–3500 g), and high (> 3500 g). Furthermore, according to the degree of obesity, they were divided into two groups: obese (20% ≤) and non-obese (20% >). The change of BMI from birth to three years of age (ΔBMI) showed a strong inverse relationship with birthweight and was significantly different among the three birthweight groups (low > middle > high). The ΔBMI and BMI at three years of age were higher in obese than in non-obese children and showed significant positive correlations with the degree of obesity. Early postnatal growth might be determined by birthweight and was higher in obese than in non-obese children. The ΔBMI from birth to three years of age and BMI at age of three years could be predictive factors for pediatric obesity.

Urinary myo-inositol levels in Japanese schoolchildren with normal glucose tolerance.

Abstract Background: Urinary myo-inositol (UMI) level is elevated in adult diabetic patients, and also increases after glucose loading. However, the relationship between UMI and plasma glucose levels in children is unknown. We aimed to assess whether UMI is a practical marker for glucose intolerance in children or not. Methods: In Study 1 (328 schoolchildren), fasting and postprandial UMI were measured, with ΔUMI defined as the difference between fasting and postprandial UMI levels. In Study 2, oral glucose tolerance tests and UMI measurements were conducted in 18 children with suspected having diabetes. Results: For Study 1, ΔUMI was observed [−0.65 (−3.9, 1.35) mg/g creatinine]. For Study 2, children with diabetes or impaired glucose tolerance had a significantly higher ΔUMI than children with normal glucose tolerance. Conclusions: These studies demonstrated the normal range of UMI in children and possibility of a novel biomarker for early detection of glucose intolerance in children.