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Full-Text Articles in Life Sciences

Decarboxylation Of L-Dopa And 5-Hydroxytryptophan In Dispersed Rat Pancreas Acinar Cells, E. Yu, L. Stern, A. Tenenhouse Oct 2009

Decarboxylation Of L-Dopa And 5-Hydroxytryptophan In Dispersed Rat Pancreas Acinar Cells, E. Yu, L. Stern, A. Tenenhouse

Edward Yu

Amino acid decarboxylation activity in dispersed rat pancreas acinar cells and fractions derived by differential centrifugation of homogenate of these cells was studied. The rate of decarboxylation was measured by determining the rate of production of the [3H]-amine from [3H]-amino acid or the rate of production of 14CO2 from the [14C]-carboxy-labelled amino acid. Only the hydroxylated amino acids L-dopa and 5-hydroxytryptophan are decarboxylated by intact dispersed pancreas acinar cells or cell homogenates at all pH values and amino acid concentrations tested. The decarboxylase activity is located exclusively in the cell cytosol. Each substrate competitively inhibits the decarboxylation of the other …


Oncogenesis And Cancer Stem Cells: Current Opinions And Future Directions., Xiaoyu Cheng, Helen O'Neill Dec 2008

Oncogenesis And Cancer Stem Cells: Current Opinions And Future Directions., Xiaoyu Cheng, Helen O'Neill

Helen O'Neill

There is increasing evidence to show that only a subset of cancer cells drives the growth and progression of a tumour. These cells share similar properties with normal stem cells and are termed 'cancer stem cells'. Cancer stem cells have been identified in acute myeloid leukaemia and in some solid tumours by their distinct expression of cell surface antigens. Their long-term, self-renewing capacity is thought to be a determining factor in the maintenance and regrowth of the tumour. Studies on haematopoietic cancers show that important signalling pathways and genes for normal haematopoiesis, such as Wnt, NF-kappaB, Notch, hedgehog (Hh) and …