Developmental profile of DNA synthesis and hydrolase activities in human fetal kidney

Adult mouse kidneys become permissive to acute polyomavirus infection and reactivate persistent infections in response to cellular damage and regeneration

“…If so, the permissiveness of newborn kidneys and lack of kidney (but not mammary, skin, or bone) permissiveness in most adult mice might also be explained. It is known that newborn mouse kidneys are relatively immature and actively differentiate tubule epithelial cells (7,16,30), whereas adult kidneys are rather quiescent (6). Thus, if in vivo Py replication requires ongoing cellular differentiation, most newborn (but not adult) kidneys would be permissive.…”

Urinary Trehalase Activity Is a Useful Marker of Renal Proximal Tubular Damage in Newborn Infants

“…This observa tion indicates that urinary trehalase may reflect a maturational change of renal proximal tubular cells. Previous reports indicated that the trehalase activity of the 13-to 18-week-old fetus is about half that measured in adult human kidneys [11]. Another report described that treha lase activity in the rabbit kidney was very low at birth but increased rapidly to reach adult values by 40 days of age [12].…”

“…Therefore, it is both interesting and important to compare urinary trehalase with other enzyme activities for the ear ly detection of renal tubular damage in newborn infants. On the other hand, it has been reported that urinary tre halase derived from renal proximal tubular cells is low in fetal and newborn specimens of rabbits and human kid neys [11,12], In this report we attempted to clarify the physiological significance of urinary trehalase and then to demonstrate its reliability as a marker of cellular proliferation and/or damage of renal proximal tubules in newborn infants. (8-10) (7 -1 0 ) 5 min 9.7±0.5 9.8±0.4 9.8±0.4 (9-10) (9 -10) (9 -1 0 )…”