We applied digital gene expression profiling to determine the transcriptome of brown and white adipose tissues (BAT and WAT, respectively) during cold exposure. Male C57BL/6J mice were exposed to cold for 2 or 4 days. A notable induction of genes related to glucose uptake, glycolysis, glycogen metabolism, and the pentose phosphate pathway was observed in BAT from cold-exposed animals. In addition, glycerol-3-phosphate dehydrogenase 1 expression was induced in BAT from cold-challenged mice, suggesting increased synthesis of glycerol from glucose. Similarly, expression of lactate dehydrogenases was induced by cold in BAT. Pyruvate dehydrogenase kinase 2 (Pdk2) and Pdk4 were expressed at significantly higher levels in BAT than in WAT, and Pdk2 was induced in BAT by cold. Of notice, only a subset of the changes detected in BAT was observed in WAT. Based on changes in gene expression during cold exposure, we propose a model for the intermediary glucose metabolism in activated BAT: 1) fluxes through glycolysis and the pentose phosphate pathway are induced, the latter providing reducing equivalents for de novo fatty acid synthesis; 2) glycerol synthesis from glucose is increased, facilitating triacylglycerol synthesis/fatty acid re-esterification; 3) glycogen turnover and lactate production are increased; and 4) entry of glucose carbon into the tricarboxylic acid cycle is restricted by PDK2 and PDK4. In summary, our results demonstrate extensive and diverse gene expression changes related to glucose handling in activated BAT.

Background: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation. Objective: To analyse the association between bone mineral content and serum alkaline phosphatase and serum phosphate. Methods: Serum alkaline phosphatase and phosphate were measured at weekly intervals during admission in 108 premature infants of gestational age below 32 weeks (mean (SD) gestational age 29 (2) weeks; mean (SD) birth weight 1129 (279) g). Bone mineral content was measured at term (mean gestational age 41 weeks) by dual energy x ray absorptiometry and corrected for body size. Results: Serum alkaline phosphatase was significantly negatively associated with serum phosphate (p < 0.001). Bone mineral content was not associated with mean serum alkaline phosphatase (p = 0.8), peak serum alkaline phosphatase (p = 0.5), or mean serum phosphate (p = 0.2) at term. Conclusion: Routine measurements of serum alkaline phosphatase and serum phosphate are of no use in predicting bone mineralisation outcome in premature infants.

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In a cohort study with historical controls of non-asphyxiated very low-birth-weight infants (birth weight < or = 1500 g and gestational age < 33 completed weeks), we evaluated the use of a "minitouch" regime for stabilization after birth and treatment of respiratory distress. This combination of early (prophylactic) treatment with nasal continuous positive airway pressure and minimal handling was introduced as a routine in our Department in 1986. We compared infants born in 1987 and in 1985, when ventilator treatment was used initially in all infants with progressing respiratory distress. The frequency of mechanical ventilation was reduced significantly from 76% in 1985 to 35% in 1987 (p = 0.00001). This reduction reflected the smaller number of infants who received ventilator treatment for less than one week, whereas the frequency of long-term ventilator treatment remained unchanged. Intracranial haemorrhage grade II-IV was reduced from 49% in 1985 to 25% in 1987 (p = 0.01). Mortality rate, average duration of hospitalization, number of infants with pneumothorax, patent ductus arteriosus, need for oxygen at 28 days and number of surviving infants with handicap did not differ significantly between the two study periods. Septicaemia was diagnosed in 16% of the infants in 1987 versus 7% in 1985 (p = 0.045). This difference coincided with an increased use of total parenteral nutrition (18% in 1987 versus 3% in 1985, p = 0.007). We conclude that the minitouch regime prevents progression of respiratory distress, reduces the need for ventilator treatment and is a safe and convenient alternative to mechanical ventilation in preterm infants with mild respiratory problems.(ABSTRACT TRUNCATED AT 250 WORDS)