It is known that hyperprolactinemia in adolescence is a rare cause of delayed or arrested puberty and growth disturbance. We studied the case of a 15-year-old girl with hyperprolactinemia, obesity, short stature and primary amenorrhea. She had had galactorrhea since 13 years of age, and menarche had not yet been seen by the age of 15. Her serum prolactin level was extremely high (328 ng/ml), but the other hormones examined were almost within the normal range. The serum prolactin constantly maintained high levels during Insulin+TRH+LH-RH infusion, indicating no reaction to TRH administration. Her sella turcica was slightly flattened on plain X-ray films. Plain and enhanced computed tomograms (CT) of the head were normal, and the pituitary stalk was seen to have shifted to the right on magnetic resonance imaging (MRI). Her serum prolactin level was reduced to 46.1 ng/ ml by treatment with oral administration of bromocriptine (2.5 mg/day). The level of prolactin was further decreased when the dose of bromocriptine was gradually increased, and galactorrhea almost ceased and menstruation occurred. Prolactinoma in adolescence may also be easily and effectively managed by medical therapy. All clinicians who see patients with arrested puberty and/or primary amenorrhea should therefore be aware of the possibility of this diagnosis.

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Data for a total of 287 prepubertal patients with growth hormone deficiency (GHD) from the International Cooperative Growth Study (ICGS) treated with recombinant growth hormone (GH) for more than two years were analyzed for the relationship between adiposity and growth response. The percent overweight index was used for assessing the degree of adiposity. One hundred eightyeight patients with GH neurosecretory dysfunction on GH treatment from the same database served as controls. Results: There was a statistically significant decline in % overweight only during the first year. There was no change in adiposity between the first and second year. In a comparison between thin patients with GHD and obese patients, obese patients had better first year growth response (height velocity, its SD score, increase in height SD score) despite older age, and lower GH dosage/kg. Among obese children with GHD, there was a tendency toward better height response in more obese individuals. Simple correlation analysis revealed variables that negatively correlated with % overweight were GH peak levels, GH dosage and height velocity before treatment and variables that positively correlated were the number of injections/week and the first year growth response. Multiple regression analysis in patients with GHD and GH neurosecretory dysfunction revealed that adiposity is an independent factor promoting height response during the first year of GH treatment in prepubertal GHD patients.

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We developed a mass screening system for short stature in elementary school children. The subjects of this mass screening were 153, 679 pupils. This screening was done in two steps. In the primary screening, children with possible short stature were screened according to height criteria by grade designed to perform simple and efficient selection. In the second step, children with height below a - 2SD score were screened according to height criteria by chronological age. The case report forms, with body measurements, growth curve and height velocity curve for positive cases in the second screening, were returned to the mass-screening center where the need for further evaluation was determined. Of all the subjects, 2, 331 were classified as positive. The necessity for further evaluation was recommended in 273. Ninety-six of the 273 were actually seen at hospitals, and underlying diseases were revealed in 19 of them (GH deficiency, 10; hypothyroidism, 2; Turner syndrome, 6; and renal tubular acidosis, 1). The results indicate that short-stature children can be identified more efficiently without any particular additional examination, if body measurements obtained by annual checkups in school are combined with growth and annual height velocity curves.

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The effect of snacking before going to sleep on the nocturnal secretion of GH was investigated in 7 children with non-GH deficiency short stature. Each child was tested on two nights: on one night, the child ate a snack before going to bed, but on the other night, the child did not. Serum GH concentrations were measured every 20 min during the first 3 h of sleep. GH concentrations in urine collected the following morning were also examined. Mean and maximum serum GH values, and urinary GH concentrations were lower in all of the children when they had eaten a snack before going to bed.

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In Turner's syndrome, the detection of Y chromosome sequences is very important because the presence of the Y chromosome increases the risk of gonadoblastoma induction. Some recent studies have indicated the presence of the Y chromosome in patients with Turner's syndrome, by methods in which the Y chromosome was not detected by a standard cytogenetic method, but these studies concentrated on a part of the Y chromosome or used an insensitive methods. In this study, we approached the detection of Y chromosome sequences by a sensitive method, polymerase chain reaction (PCR) with seven pairs of primers that span the Y chromosome, followed by Southern blot analysis, in eleven Japanese patients with Turner's syndrome. Ten of the eleven patients had some Y chromosome sequences determined by PCR followed by Southern blot. This suggests that most patients with Turner's syndrome have cryptic Y chromosomes, but further studies and long-term follow-up of patients with the Y chromosome are needed to support our data and to clarify the significance of a small amount of Y chromosome.

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The hypophosphatemic (Hyp) mouse is a useful model for studying certain genetic defects in renal phosphate (P_i) handling in humans. Sodium-dependent phosphate transport activity was measured in brush border membrane vesicle (BBMV) prepared from renal cortex and in Xenopus oocytes that had been injected with renal poly (A) +RNA. Pi transport activity in Hyp mice was significantly reduced compared with the control. Northern blot analysis revealed that the level of NaP_i-7 mRNA was reduced in Hyp mice. Hybrid depletion study showed that the decrease in P_itransport activity in Hyp mice was primarily due to reduced expression of NaP_i-7 mRNA. Immunohistochemical staining for control mice confirmed the localization of NaP_i-7 protein in the brush border membrane (BBM) of proximal convoluted tubules. In contrast, the staining was decreased in the membrane, but increased in intracellular structures of Hyp mice, suggesting that an abnormality of endocytosis/exocytosis in BBM is also involved in Hyp mutation. In conclusion, the defect in renal phosphate reabsorption in Hyp mice resulted from a reduction in mRNA and protein for NaP_i-7 in the proximal convoluted tubules of midcortical and superficial nephrons.

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In Japanese children, we measured total body bone mineral content (TBMC), total body fat (TBF) and total body lean (TBL) in 59 in elementary school, 83 in junior high school and 51 in high school, by dual energy X-ray absorptiometry (DEX ODR-2000). The objective of the study was to clarify body composition including bone mineral content (BMC), fat mass and lean mass at various ages, and the relationship between BMC and fat or lean. Lumbar bone mineral density (L2-L4 BMD; g/cm²) was also calculated from the BMC (g) and area (cm²). TBF in girls and TBL in boys increased significantly at age 12 years, although TBMC was similar in both sexes. The ratios of TBMC, TBF and TBL at age 18 years were 5.7%, 13.8% and 80.5% in males, and 8.0%, 26% and 66% in females, respectively. BMC in the extremities increased with lean body mass from age 10 years in boys, and spinal and pelvic BMC increased with the fat mass of the trunk from age 10 years in girls. In girls, TBMC was significantly related to lean in the trunk (r=0.325; p<0.01), independently of age, height and weight. In both sexes, TBMC was significantly negative related to fat in the trunk (girls: r=-0.305; p<0.01, boys: r=-0.537; p<0.01), independently of age, height and weight.

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