Does levodopa availability improve with progression of Parkinson 's disease?
Levodopa availability improves with progression of PD. This may result from deteriorated peripheral activity of levodopa metabolising enzymes or an increasing enteric dysfunction with subsequent better duodenal levodopa absorption or both.
K-ras mutations are common events in normal, hyperplastic, metaplastic, and neoplastic pancreatic ductal cells. Because K-ras mutations frequently, although not exclusively, are related to mucinous differentiation of pancreatic cells, this mutation may not cause but only promote mucinous differentiation. The prevalence of a certain mutation pattern in nonneoplastic and neoplastic ductal cells in an individual pancreas suggests the dominance of one carcinogenic factor.