Dong-Gwan Han

Low total body bone mineral content and high bone resorption in Korean winter-born versus summer-born newborn infants☆☆☆★★★

Seasonal differences in newborn total body bone mineral content (TBBMC) have not been studied, particularly in relation to alterations in vitamin D status in winter. In vitamin D deficiency bone resorption may be high and bone mineralization low. Bone resorption may be assessed by serum cross-linked carboxyterminal telopeptide of type I collagen (ICTP) measures. Because vitamin D supplements throughout pregnancy are uncommon in Korea, we hypothesized that in Korean winter newborns, TBBMC is low and serum ICTP high from high bone resorption and low 25-hydroxyvitamin D (25-OHD) compared with those in summer newborns. Seventy-one Korean term infants were studied prospectively in summer (July through September, n = 37) versus winter (January through March, n = 34); TBBMC was measured before 3 days of age by dual-energy x-ray absorptiometry. Significant seasonal differences were found: winter newborns had 6% lower TBBMC (least squares means +/- SD; 86.7 +/- 7.7 gm vs 93.9 +/- 7.8 gm, p = 0.0002), lower cord serum 25-OHD (10.7 +/- 8 nm vs 30 +/- 15 nm, p = 0.0001) and 1,25-dihydroxyvitamin D, and higher ICTP (96.4 +/- 20.3 microg/L vs 74.8 +/- 24 microg/L, p = 0.0002) and calcium than summer newborns. TBBMC correlated with serum 25-OHD (r = 0.243, p = 0.047) and inversely with ICTP (r = -0.333, p = 0.008). We suggest that in Korea low maternal vitamin D status in winter results in marked reduction in newborn TBBMC.

Improved surface active properties of perfluorocarbon and exogenous pulmonary surfactant mixtures. ♦ 1804

Improved surface active properties of perfluorocarbon and exogenous pulmonary surfactant mixtures. ♦ 1804

Low Serum Aminoterminal Propeptide of Type III Procollagen (PIIINP) Concentration in Winter-Versus Summer-Born Newborn Infants † 1556

Low Serum Aminoterminal Propeptide of Type III Procollagen (PIIINP) Concentration in Winter-Versus Summer-Born Newborn Infants † 1556

Bone Resorbing Cytokines in Rickets of Prematurity 1555

Interleukin-6 (IL-6), produced by stromal-osteoblastic cells in response to interleukin-1 (IL-1), parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D[1,25(OH)2D], stimulates early osteoclast formation and bone resorption cooperatively with IL-1 in vivo. In adult osteoporosis, serum IL-6 is increased related to the loss of gonadal function and bone loss. Possible role of bone resorbing cytokines in rickets of prematurity has not been studied. In rickets of prematurity, we showed high serum cross-linked carboxyterminal telopeptide of type I collagen (ICTP, bon resorption marker) & osteocalcin(bone turnover marker) vs. controls; & high serum PTH & 1,25(OH)2D (Pediatr Res 35:317A, 1993). We hypothesized that serum IL-6& IL-1β would be high in preterm infants with rickets compared with infants without rickets; and bone turnover markers will be positively correlated with bone resorbing cytokines, reflecting increased osteoclastic activity by bone resorbing cytokines. Radiographic rickets was diagnosed in 17 preterm infants aged 37±12d (mean±SD) in Korea, gestational ages 30.5±1.7wks & birth weight 1333±135g. 14 controls (31.1±2.4wks; 1360±172g) had normal bone x-rays and serum biochemistry at enrollment (43±15d). Serum IL-6 & IL-1β were measured by enzyme immunoassay(Genzyme, Cambridge, MA). In rickets vs. controls, serum IL-6 concentration was similar (median with ranges; 43.5[3.91-120.1] vs. 37.8[0.82-81.3] pg/mL, p=0.9); serum IL-1β was similar (8 [2.2-59.3] vs. 7.9 [0.72-17.6] pg/mL, p=0.8). In rickets, serum ICTP was positively correlated with serum IL-1β (r=0.677, p=0.003); serum osteocalcin was negatively correlated with serum IL-6 (r=-0.846, p=0.001). Serum IL-6 or IL-1β did not correlate with serum PTH or 1,25(OH)2D. Since serum ICTP positively correlated with serum IL-1β; and serum osteocalcin negatively correlated with serum IL-6, we suggest that IL-6 and IL-1β may be involved in the high bone turnover in rickets of prematurity, but the relationships are complex.

In vitro inactivation of surface active properties of pulmonary surfactant by hydrogen peroxide and ferrous sulfate and possibility of prevention by antioxidant enzymes 1962

In vitro inactivation of surface active properties of pulmonary surfactant by hydrogen peroxide and ferrous sulfate and possibility of prevention by antioxidant enzymes 1962

Budesonide protects surface active properties of surfactant in newborn rats exposed to hyperoxia. 1957

Budesonide protects surface active properties of surfactant in newborn rats exposed to hyperoxia. 1957

In vitro inactivation of surface active properties of pulmonary surfactant by hydrogen peroxide and reversal by catalase. † 1566

In vitro inactivation of surface active properties of pulmonary surfactant by hydrogen peroxide and reversal by catalase. † 1566