title: Thymidine factor in human cord sera and relationship to birth size, gestational age and insulin.
abstract: Thymidine factor was studied in human cord sera from 44 neonates with gestational ages ranging between 36 and 43 weeks. Thymidine factor was determined by the uptake of 6-3H-thymidine using isolated chick embryo cartilage cells. The thymidine factors increased with gestational age and those of neonates at 40 weeks of gestation were 0.89 +/- 0.17 U/ml (mean +/- SD), but were significantly lower after 42 weeks of gestation. There was no correlation between thymidine factor in cord sera and birth weight or size. There was a positive correlation (p less than 0.02) between insulin level and thymidine factor in cord sera. Our data suggest that somatomedin measured as thymidine factor might not have a major role in fetal growth and insulin might be an important factor in the synthesis of somatomedin by the fetus.
mesh_terms: D001724:Birth Weight; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005312:Fetal Blood / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood*; D013002:Somatomedins / Q000096:biosynthesis / Q000378:metabolism; D013936:Thymidine / Q000097:blood*
chemical_list: D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013002:Somatomedins; D013936:Thymidine