2-acetylaminofluorene-induced unscheduled DNA synthesis in hepatocytes isolated from 3-methylcholanthrene treated rats.

The dose-dependent induction of unscheduled DNA synthesis (UDS) by 2-acetylaminofluorene (AAF) and N-OH-2-acetylaminofluorene (N-OH AAF) in primary rat hepatocytes isolated from untreated and 3-methylcholanthrene (3-MC) treated rats was investigated. 3-MC treatment was not necessary for the dose-dependent induction of UDS induced by N-OH AAF, suggesting the presence of enzyme levels adequate for its esterification to an active form in isolated primary hepatocytes. Although all doses of AAF increased the level of [3H]thymidine incorporation above that of the control, a dose-dependent response could not be demonstrated, suggesting inadequate constitutive levels of N-hydroxylating enzymes.

Homozygotes for the hereditary persistence of fetal hemoglobin: the ratio of G gamma to A gamma chains and biosynthetic studies.

Two sons of a previously reported Ghanaian homozygote for the hereditary persistence of fetal hemoglobin (HPFH) (Ringelhann et al., 1970) also are HPFH homozygotes. In addition, another unrelated adult Ghanaian homozygote has been detected.

Measurement of the rate of flow of dry matter in digesta passing through the duodenum of sheep.

1. A total of seven sheep fitted with re-entrant cannulas in the proximal duodenum were used in three experiments to measure the passage of dry matter (DM) in duodenal digesta. 2.