Yasusada Kawada

Plasma visfatin concentration as a surrogate marker for visceral fat accumulation in obese children.

Objective: This study was designed to elucidate whether the plasma visfatin level reflects visceral or subcutaneous fat accumulation and metabolic derangement in obese children.

Stimulation of catecholamine synthesis by orexin-A in bovine adrenal medullary cells through orexin receptor 1.

Orexin-A has recently been identified as a new hypothalamic peptide working as a mediator in the regulation of feeding behavior and sleep control. To determine the role of orexin-A in peripheral metabolic processes, we examined direct effects of orexin-A on catecholamine synthesis and secretion in cultured bovine adrenal medullary cells. Incubation of cells with orexin-A (100 pM) for 20 min caused a small but significant increase in 14C-catecholamine synthesis from [14C]tyrosine, but not from L-3,4-dihydroxyphenyl[3-14C]alanine. Orexin-A (100 pM) potentiated the stimulatory effects of acetylcholine (0.3 mM) on 14C-catecholamine synthesis. Orexin-A significantly increased tyrosine hydroxylase activity, which was evident at 1 pM and maximal at 100 pM. 4 beta-Phorbol-12 beta-myristate-13 alpha-acetate, an activator of protein kinase C, did not enhance the stimulatory effects of orexin-A on tyrosine hydroxylase activity, while H-7 and staurosporine, inhibitors of protein kinase C, nullified the effects of orexin-A. Orexin-A had little effect on catecholamine secretion from the cells. Orexin receptor 1 (OX(1)R) but not orexin receptor 2 (OX(2)R) mRNA was detected in bovine adrenal medullary cells by reverse transcriptase-polymerase chain reaction. These findings suggest that orexin-A activates tyrosine hydroxylase and then stimulates catecholamine synthesis, probably via activation of the OX(1)R-protein kinase C pathway in adrenal medullary cells.

Plasma Levels of Orexin-A and Leptin in Obese Children

The present study was designed to determine the plasma level of orexin and its relationship with other metabolic and anthropometric markers in obese children. Forty-seven obese Japanese children, consisting of 31 boys and 16 girls, were enrolled in the study. Their ages were 10.4 ± 0.5 (mean ± s.e.m.) yr, and their percentage overweight was 42.9 ± 1.9%. Blood was drawn after an overnight fast. The age-matched control group consisted of 26 nonobese children, 13 boys and 13 girls. Plasma orexin-A concentration was higher in obese children (17.0 ± 0.4 pg/ml; p<0.001) than in the control children (13.5 ± 1.1 pg/ml). Similarly, plasma leptin concentration was higher in obese children (12.0 ± 1.0 ng/ml; p<0.001) than in the control children (5.2 ± 0.4 ng/ml). There was a highly significant positive correlation between the two parameters in the obese children (r=0.49, p<0.001). Plasma orexin-A level was correlated significantly with waist-to-hip ratio, while leptin level was correlated with percentage overweight, waist circumference and percentage body fat in the obese children. These results suggest that high plasma orexin-A level parallels the leptin level in obese children.

Sporadic pseudohypoparathyroidism type-1b with asymptomatic hypocalcemia

Pseudohypoparathyroidism type 1b (PHP‐1b) is usually diagnosed on various symptoms of hypocalcemia. Previous studies reported a few cases of autosomal dominant pattern PHP‐1b identified on familial analysis with asymptomatic hypocalcemia. Herein we report the case of a 6‐year‐old male patient with sporadic PHP‐1b incidentally detected on preoperative examination. He had neither characteristic findings of Albright hereditary osteodystrophy nor evidence of tetany. Sporadic PHP‐1b was diagnosed on the basis of clinical observation and laboratory examination. In addition, genetic testing using methylation‐specific multiplex ligation‐dependent probe amplification indicated broad methylation abnormalities and confirmed the sporadic form of PHP‐1b. Sporadic PHP‐1b might often be overlooked when diagnosis is done simply on definitive clinical features. To avoid this, DNA sequencing and methylation analysis should be performed even in the absence of definitive clinical features.

Tamoxifen Treatment for Pubertal Gynecomastia in Two Siblings with Partial Androgen Insensitivity Syndrome

Background: Although tamoxifen has been shown to be fairly safe and effective for idiopathic pubertal gynecomastia, it remains unknown whether it is also beneficial for gynecomastia associated with endocrine disorders. Here, we report the effect of tamoxifen on pubertal gynecomastia in 2 siblings with partial androgen insensitivity syndrome (PAIS). Case Reports: Cases 1 and 2 presented with persistent pubertal gynecomastia at 13 and 16 years of age, respectively. Physical examinations revealed breast of Tanner stage 3 and normal male-type external genitalia in both cases. Clinical features such as female-type pubic hair and borderline small testis indicated mildly impaired masculinization. Results: Molecular analysis identified a previously reported p.Arg789Ser mutation in the androgen receptor gene (AR) in the 2 cases. Two months of oral administration of tamoxifen ameliorated gynecomastia to Tanner stage 2 with no adverse events. Additional treatment with testosterone enanthate showed negligible effects on body hair and penile length. Hormone values of the 2 cases during tamoxifen treatment remained similar to those in previously reported untreated patients with PAIS. Conclusion: The results indicate that tamoxifen was effective in treating pubertal gynecomastia in these 2 patients with PAIS and may be considered as a therapeutic option in this situation pending further studies.

High prevalence of eosinophilia in growth hormone‐deficient children

Abstract Background : To determine the clinical significance of eosinophilia in growth‐hormone (GH)‐deficient children, a clinical study consisting of 72 children and adolescents (mean age 9 years and 6 months at diagnosis) with GH deficiency (GHD) was undertaken. Patients were treated with GH, along with supplementation for the combined deficiency in patients with multiple hormone deficiency.

Small for Gestational Age児における成長ホルモン分泌不全の合併についての検討

Growth hormone (GH) therapy for short children born small for gestational age (SGA) has been approved in Japan. It is important to evaluate GH secretion ability before the initiation of GH therapy because there are some differences in dose and medical expenses between short children born SGA and GH deficiency (GHD). This study was designed to elucidate the incidence of GHD and to find a useful marker for detecting it in short SGA children. We retrospectively reviewed medical records to analyze the clinical features of short children born SGA and with GHD who had started GH therapy before the age of 6 in the University Hospital of Occupational and Environmental Health and Kyushu Rousai Hospital. Nine of 22 SGA subjects (41%) had GHD. There were no significant differences between two groups of short SGA children (GHD, non-GHD) in the median of height and serum insulin-like growth factors (IGF)-1 levels at birth or at the start of GH therapy. The probability of GHD was higher if the height standard deviation scores (SD) of the SGA children were lower than -3.2 (odds ratio, 11.6; 95% confidence interval, 1.52 - 89.1, P = 0.013). This study showed that there is an approximately 40% incidence of GHD in short SGA children needing GH treatment. We should do GH stimulation tests for short SGA children whose height SD is lower than -3 to determine the appropriate GH therapy.

Plasma but not serum brain-derived neurotrophic factor concentration is decreased by oral glucose tolerance test-induced hyperglycemia in children

Abstract Background: Little is known regarding the relationships among circulating brain-derived neurotrophic factor (BDNF) levels and glucose or insulin in children and adolescents. The objective of this study was to investigate whether circulating BDNF levels would change during the oral glucose tolerance test (OGTT). Methods: We performed the OGTT and measured the serial changes in BDNF levels in both plasma and serum. Results: There were 22 subjects in the normal type (N) group and 20 in the borderline/diabetic type (B/D) group, defined by the results of the OGTT. Serum levels of BDNF were almost five times higher and plasma levels gradually decreased during the OGTT, whereas serum levels showed no significant change. The reduction of plasma BDNF level changes from baseline to 120 min were significantly different between the N and B/D groups (36.3% vs. 20.8%, p=0.023). Conclusions: Our results showed that plasma levels of BDNF are more sensitive to acute changes in glucose or insulin levels than serum.

An Infantile Case of Transient, Severe Hypercholesterolemia with Normalization after Complete Weaning from Breast-feeding

A 20-d-old boy was referred to our department because of hyperthyrotropinemia at neonatal mass screening and diagnosed with neonatal transient hyperthyrotropinemia. A follow-up examination when the patient was 5 mo old revealed severe hypercholesterolemia. Familial hypercholesterolemia was first suspected because of the patient’s significantly high levels of total and low-density lipoprotein cholesterol. The parent’s serum lipid profiles were examined and found to be normal. He was completely breast-fed until 6 mo of age. Breast milk was still the main source of food for a period following weaning. At 14 mo old, the patient was weaned completely from breast milk, and his serum cholesterol levels decreased dramatically. According to the normal lipid profiles of the patient’s parents and the spontaneous normalization of serum cholesterol levels after complete weaning from breast milk, breast-feeding was suggested to be responsible for his transient severe hypercholesterolemia. It is well documented that breast-fed infants have higher serum cholesterol levels than formula-fed infants. However, there is no reported case with severe hypercholesterolemia equivalent to or higher than the levels observed in the case of familial hypercholesterolemia. Although the exact mechanism is unknown, it is necessary to consider that a small number of cases develop severe hypercholesterolemia related to breast-feeding.