Jun-ichi Nagaishi

Novel missense mutation in the IGF‐I receptor L2 domain results in intrauterine and postnatal growth retardation

IGFs play key roles in intrauterine and postnatal growth through the IGF‐I receptor (IGF‐IR). We identified a family bearing a new heterozygous missense mutation at the L2 domain of IGF‐IR (R431L).

An Infant with Pseudohypoaldosteronism Accompanied by Cholelithiasis

A case of an infant with very rare concurrence of pseudohypoaldosteronism and cholelithiasis is described. Aldosterone concentration was extremely high (64.6 nmol/l; normal 0.03-4.4 nmol/l) and fludrocortisone did not have favorable effects on hyperkalemia (7.4 mEq/l) and hyponatremia (124 mEq/l). A gallstone was found using ultrasonography at age 6 months, and it was extirpated surgically. The combination has not been reported previously. The study supports the previous hypothesis that cholelithiasis is found more often in infants with dehydration or electrolyte derangement.

Laminar cortical necrosis in adrenal crisis: Sequential changes on MRI

We describe the serial magnetic resonance imaging (MRI) findings in a six-year-old girl with congenital adrenal hyperplasia, who presented with seizures and unconsciousness during a hypoadrenal crisis. Initial neuroimaging revealed the presence of brain edema with high signal changes in the fronto-parietal cortex on diffusion-weighted MRI. The brain edema worsened four days into admission, and by day 14 low-density areas were seen over the frontal lobes bilaterally using computed tomography (CT). Follow-up MRI at between one and two months of admission revealed extensive white matter lesions with high intensity on T2-weighted images (T2WI) and fluid-attenuated inversion recovery (FLAIR) images, which extended into deep cortical layers. Additionally, linear lesions with high signal change on T1-weighted imaging developed in the superficial cortical layers, with frontal predominance. This layer appeared isointense on T2WI and high intensity on FLAIR images, suggesting laminar cortical necrosis. Two months later, linear, cavitary lesions appeared in the middle cortical layers between the aforementioned superficial laminar abnormality and deep cortex/white matter lesions. The high-intensity signals in the deep cortical layers remained contiguous with the white matter lesions. This unique type of multi-layered cortical lesion may have resulted from a complex combination of hypoglycemia and hypoxia/ischemia in the setting of adrenal insufficiency.

Variation analysis of β3‐adrenergic receptor and melanocortin‐4 receptor genes in childhood obesity

Background: Decreased energy expenditure and increased food intake are principal causes for obesity. In the present study, genotypes of β3‐adrenergic receptor (β3AR) and of melanocortin‐4 receptor (MC4R), both of which are believed to have a close link to the cause of obesity, were analyzed and compared with phenotypes of childhood obesity.

Lower brainstem dysfunction in an infant with persistent primitive trigeminal artery

A 6-month-old boy with persistent primitive trigeminal artery (PPTA) presented with stridor, dysphagia, delayed motor development and postural neck and shoulder dystonia. Magnetic resonance imaging/angiography and ultrasonography revealed PPTA, with flow from the dilated basilar artery to the right internal carotid artery, lower brainstem compression by the dilated basilar artery, and cerebellar vermis hypoplasia. Evoked potentials showed lower pons and medulla oblongata functional disruption. These lesions may be related to vascular etiology in the lower brainstem or to congenital malformation syndrome involving infratentorial structures. The relationship of this condition to Möbius syndrome is discussed.

Usefulness of a stature-based standard of skinfold thickness, especially for short children

Skinfold thicknessess (SFT) were measured at ulnar, triceps, subscapular and suprailiac sites in 730 boys and 724 girls (age 3–12 years) whose stature ranged from 100 to 150 cm and whose weight was within ±20% of the average. Means and standard deviation (SD) were calculated after logarithmic transformation of the original skinfold readings to demonstrate stature‐based standards of SFT in Japanese children. The means of SFT exhibited nadirs (boys/ girls: ulnar 5.1/5.9 mm, triceps 7.9/9.5 mm, subscapular 4.9/6.1 mm, suprailiac 4.5/6.2 mm) in subjects 110–115 cm tall except for ulnar SFT in girls. SFT values increased as children increased in stature. Standard deviations of SFT at the four sites in short children (staturte < mean −1 SD) were estimated using the stature‐based standard as well as an age‐based standard. Susms of the SDs assessed by the age‐based standard were significantly smaller than those assessed by the stature‐based standard in boys (P < 0.05) and girls (P < 0.01) with short stature, suggesting that SFT in short children was falsely understimated by the age‐based standard. Thus, the stature‐based standard is beneficial for the assessment of SFT, especially in children whose stature is below the mean −‐1 SD.

Evaluation of Fetal Thyroid with 3D Gradient Echo T1-weighted MR Imaging

Purpose: The characteristics of fetal thyroid on magnetic resonance (MR) imaging, including normal thyroid and disorders other than goiter have not been fully evaluated. Our aim was to assess fetal thyroid using three dimensional (3D) gradient echo (GRE) T1-weighted MR imaging and to examine the usefulness of this modality. Materials and Methods: The study included 27 3D GRE T1-weighted images from 26 fetuses. The largest possible region of interest (ROI) within the thyroid at the slice level depicting the thyroid was manually defined and three circular ROIs on neck muscle were manually defined on the image slices showing the highest signal intensity (SI) of the thyroid. Maximum and mean thyroid-to-muscle SI ratios (SIRs) were then calculated as SIR = maximum or mean thyroid SI/muscle SI. Results: The thyroid could not be identified in two cases. Fetal thyroid function was normal in 17 cases, and there were 7 cases of hypothyroidism (6 transient and 1 thyroid dysgenesis). There was no linear relationship between mean and maximum SIR and gestational age. The mean and maximum SIR in the cases of normal fetal thyroid were 1.85 ± 0.20 and 2.61 ± 0.39, and the mean and maximum SIR in fetal hypothyroidism were 1.58 ± 0.20 and 2.13 ± 0.37. Mean (P = 0.0088) and maximum (P = 0.0221) SIR values were significantly different between euthyroid and hypothyroid fetuses. Conclusion: Thyroid SIR measurement provided useful information regarding fetal thyroid function.

Fat areas on the extremities in normal weight and overweight children and adolescents: Comparison between age-related and weight-related changes in adiposity

The purpose of the study was to compare changes in fat distribution in association with obesity and puberty in adolescent boys and girls. Fat areas at the ulnar, triceps, thigh, and calf regions were measured in normal weight prepubertal children (P) and adolescents (N), and overweight adolescents (O). There were significant differences in fat areas at the four sites between N and O of both sexes, especially in the proximal extremities (triceps, thigh) in boys. On the other hand, fat areas on the extremities of N boys and girls were not significantly different from those of P children except for thigh fat area in girls. It is suggested that pubertal maturation in girls, but not in boys, is associated with increased adiposity on the legs, particularly in the proximal regions, and that there are sex differences between changes in fat distribution associated with puberty and obesity.