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Transforming growth factor beta (TGF-beta) is a growth factor with multiple biological properties including stimulation and inhibition of cell proliferation. To determine whether TGF-beta is involved in hepatocyte growth responses in vivo, we measured the levels of TGF-beta mRNA in normal liver and during liver regeneration after partial hepatectomy in(More)
When growth is stimulated in the normally quiescent adult rat liver by partial hepatectomy, steady state levels of messenger RNAs (mRNAs) for c-fos, c-myc, and p53 increase sequentially during the prereplicative phase which precedes DNA synthesis. Levels of c-fos mRNA are elevated at least 4-fold within 15 min after partial hepatectomy and decrease rapidly(More)
The transforming growth factor (TGF) beta s are multifunctional polypeptide growth factors with diverse biological effects, including inhibition of epithelial cell proliferation both in vitro and in vivo. To investigate the possible role of TGF beta 1 in the regulation of papillomavirus infection and papillomavirus-associated transformation, we compared the(More)
In rats maintained on a carcinogenic diet (choline deficient containing 0.1% ethionine), the levels of c-myc and p53 mRNAs increased by 4 wk after animals were placed on the diet. Cell isolation studies showed that the change in c-myc takes place in oval cells, while p53 increases predominantly in oval cells but also in hepatocytes. To determine whether(More)
We have established an in vivo/in vitro system in which epithelial cells ("oval cells") isolated from livers of rats fed a carcinogenic diet for a very brief period are placed in culture and transfected with an oncogene. Injection s.c. into nude mice of oval cells transfected with the activated c-Ha-ras (EJ oncogene) produces tumors with morphological(More)
Over the past decade, numerous studies have documented profound racial and ethnic disparities in disease in the United States. This essay examines how popular and scientific concepts of race and ethnicity converge with dominant understandings of genetics to inform the design and interpretation of research, public health policy, and medical practice.(More)
Is it good medical practice for physicians to " eyeball " a patient's race when assessing their medical status or even to ask them to identify their race? This question was captured in a 2005 episode of " House M.D., " Fox television's medical drama. In the episode, a black patient with heart disease refuses a hospital physician's prescription for what is(More)
We have used a system of nutritional manipulation to investigate whether hepatocytes of the normal liver can be primed for replication in vivo. In this system, rats that are denied protein for 3 days undergo a burst of hepatic DNA synthesis and mitosis when they are refed amino acids, while normally fed or starved rats do not respond. To determine if(More)
When growth is stimulated in normally quiescent hepatocytes, steady-state levels of c-fos, c-myc, and p53 mRNAs increase sequentially and transiently before DNA replication. C-fos mRNA increases almost immediately after partial hepatectomy and decreases by 2 hr; c-myc mRNA reaches maximal levels between 30 min and 2 hr. In contrast, the p53 mRNA increase(More)