Stephen E. Mercer

Learn More
Little is known about the cells or mechanisms of O2 chemoreception in vertebrates other than mammals. The purpose of this study, therefore, was to identify O2-sensitive chemoreceptors in a fish. Putative O2-sensitive chemoreceptors were dissociated from the gills of channel catfish, Ictalurus punctatus, and cultured. A population of cells was identified(More)
Stress signals activate the SAPK/JNK and p38 MAPK classes of protein kinases, which mediate cellular responses, including steps in apoptosis and the maturation of some cell types. We now show that stress signals initiated by transforming growth factor-beta 1 (TGF-beta 1) induce G(1) arrest through protein stabilization of the CDK inhibitor p21(Cip1).(More)
The phosphorylation of cyclin D1 at threonine 286 by glycogen synthase kinase 3beta (GSK3beta) has been shown to be required for the ubiquitination and nuclear export of cyclin D1 and its subsequent degradation in the proteasome. The mutation of the nearby residue, threonine 288, to nonphosphorylatable alanine has also been shown to reduce the(More)
We report a 50-year-old woman who presented with a six-month history of recurrent retiform purpura of uncertain etiology. Laboratory findings included neutropenia, positive anticardiolipin IgM antibody, and a weakly positive p-ANCA. Histopathology revealed a leukocytoclastic vasculitis with intravascular thrombi. Urine toxicology screen was positive for(More)
Ductal adenocarcinoma of the pancreas is almost uniformly lethal as this cancer is invariably detected at an advanced stage and is resistant to treatment. The serine/threonine kinase Mirk/Dyrk1B has been shown to be antiapoptotic in rhabdomyosarcomas. We have now investigated whether Mirk might mediate survival in another cancer in which Mirk is widely(More)
Mirk/dyrk1B is a member of the dyrk/minibrain family of serine/threonine kinases that mediate the transition from growth to differentiation in lower eukaryotes and mammals. Depletion of endogenous Mirk from C2C12 myoblasts by RNA interference blocks skeletal muscle differentiation (Deng, X., Ewton, D., Pawlikowski, B., Maimone, M., and Friedman, E. (2003)(More)
Nonmelanoma skin cancer (NMSC) is the most common form of cancer in the Caucasian population, with squamous cell carcinoma (SCC) accounting for the majority of NMSC-related metastases and death. While most SCC lesions are indolent tumors with low malignant potential, a wide diversity of SCC subtypes exist, several of which are associated with markedly more(More)
Amyloidosis cutis dyschromica is a rare form of cutaneous amyloidosis in which there is deposition of keratinocyte-derived amyloid with involvement of almost the entire integument, leading to diffuse dyschromia without associated systemic abnormalities. We report the case of a 40-year-old female who presented with the onset of diffuse hyperpigmentation(More)
Acquired Perforating Dermatosis (APD) is a perforating disease characterized by transepidermal elimination of dermal material [1,2]. This disease usually develops in adulthood. APD has been reported to occur in association with various diseases, but is most commonly associated with dialysis-dependent chronic renal failure (CRF) or diabetes mellitus (DM)(More)
Elevated levels of the cyclin-dependent kinase (CDK) inhibitor p27 block the cell in G(0)/G(1) until mitogenic signals activate G(1) cyclins and initiate proliferation. Post-translational regulation of p27 by different phosphorylation events is critical in allowing cells to proceed through the cell cycle. We now demonstrate that the arginine-directed(More)