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A recent survey found that approximately 4% of very low birth weight infants in Japan were treated with glucocorticoids postnatally for circulatory collapse thought to be caused by late-onset adrenal insufficiency. We identified 11 preterm infants with clinical signs compatible with this diagnosis (hypotension, oliguria, hyponatremia, lung edema, and increased demand for oxygen treatment) and matched them for gestational age with 11 infants without such signs. Blood samples were obtained for cortisol and its precursors from the patient group before the administration of hydrocortisone, and from the control group during the same postnatal week. All samples were analyzed using a gas chromatography-mass spectrometry system. Cortisol concentrations did not differ between the two groups (6.6 Ϯ 4.5 vs 3.4 Ϯ 2.7 g/dL); however, the total concentration of precursors in the pathway to cortisol production was significantly higher in the patient group (72.2 Ϯ 50.3 vs 25.0 Ϯ 28.5 g/dL; p Ͻ 0.05). We conclude that the clinical picture of late-onset adrenal insufficiency in preterm infants is not a result of an absolute deficiency of cortisol production, but may be a result of a limited ability to synthesize sufficient cortisol for the degree of clinical stress. A ccording to a recent nationwide survey in Japan, about 4% of very low birth weight (VLBW) infants are treated with postnatal steroids because of adrenal insufficiency of prematurity (AOP). This condition was defined in the survey as postnatal steroid usage during a hospital stay for treatment of late-onset circulatory collapse in premature infants (1). Reports on glucocorticoid-responsive hypotension among VLBW infants in the early postnatal period suggest that the hypothalamus-pituitary-adrenal system does not function sufficiently in the immediate postnatal period (2-7), and, as a result, the serum cortisol level is relatively low during the first week of life (8 -13). However, it has been suggested that this adrenal insufficiency in preterm infants is transient and that adrenal function tends to return to normal by the end of the second week of life (14). Two randomized control trials have demonstrated the benefit of glucocorticoids for preventing and treating refractory hypotension during the first week of life in VLBW infants (15,16). Therefore, glucocorticoid-responsive hypotension was not considered a common phenomenon beyond the first week of life in this population. However, VLBW infants sometimes develop late-onset glucocorticoid-responsive circulatory collapse.The purpose of the current study differs from previous reports on the above pathophysiological etiologies, because we focused specifically on late-onset circulatory instability, which is usually prominent after the first week of life in preterm infants. AOP was defined as postnatal steroid treatment for late-onset (after the first week of life) adrenal insufficiency in premature infants. To elucidate the pathogenesis of this disorder, a comparison of steroid hormone concentrations between ...

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The egg morphology and successive changes in the developing embryos of the carabid ground beetle Carabus insulicola (Carabidae) are described based on light and scanning electron microscopy observations. Newly laid eggs of this species are ellipsoid and measure approximately 6.1 × 2.9 mm, before increasing to 6.6 × 3.4 mm at hatching. The egg period is about 11 days at 23°C. The egg shell is characterized by a thin fragile chorion covering a hard serosal cuticle. The embryo forms on the ventral egg surface, where it develops for the duration of the egg period. During the process of thoracic leg formation, two subcoxal rings, subcoxae-1 and 2, are clearly discernible at the basalmost region of the leg rudiments, and these subcoxae participate in the formation of the larval pleura and sterna. The result thus provides tangible evidence for the subcoxal theory, that is, that thoracic pleura and sterna are derived from subcoxal regions. Despite the complete absence of abdominal appendages in the larvae of this species, two pairs of appendage-like swellings, the medial and lateral ones, temporarily arise in the first eight abdominal segments during the middle of embryonic development. The medial swellings are assumed to be serially homologous with the coxal part of the thoracic leg, and they later flatten out and participate in the formation of the larval pleura (hypopleurites). In the light of the serially homologous relationships among gnathal appendages, thoracic legs, and abdominal appendage-like swellings, we identified the subcoxal regions in both the gnathal and abdominal segments. Although, the lateral swellings soon degenerate and disappear, it is considered that the swellings originate in the abdominal subcoxae-2 and may be homologous to the tracheal gills of larvae of Gyrinidae. Based on the embryological results, new interpretations for the constituent of gnathal appendages are proposed.

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