Pancreatic neuroendocrine microadenomatosis presenting as a functional VIPoma.

Pancreatic microadenomas are benign tumors of neuroendocrine origin less than 5 mm in size. Whereas most microadenomas are non-functional; a few rare functional pancreatic microadenomas have been described in the setting of multiple endocrine neoplasia type one (MEN-1). In this report, we describe a unique case of multiple functional microadenomas of the pancreatic head in a patient who presented with persistent secretory diarrhea, refractory hypokalemia, metabolic acidosis and elevated plasma vasoactive intestinal peptide (VIP) levels.

Resection of a mature cystic teratoma of the liver harboring a carcinoid tumor.

Cystic teratomas are rare pluripotent embryonic tumors which most commonly originate in gonadal organs. Extra-gonadal cystic teratomas are exceedingly uncommon, accounting for only 1% of all cystic teratomas, and have been reported in unusual locations including the kidney, mediastinum and liver. These extra-ovarian cystic teratomas have also been known to harbor other neoplasms including carcinoid tumors.

Decrease in Ca-ATPase activity in aged synaptosomal membranes is not associated with changes in fatty acyl chain dynamics.

We have examined lipid peroxidation (LPO) and fatty acid acyl chain dynamics in synaptosomal membranes isolated from aged rat (Fischer 344 x Brown Norway F1 hybrids) brains, correlating these results with measurements of enzymatic activity of the synaptic plasma membrane Ca2(+)-ATPase (PMCA). Calcium-dependent ATPase activity in these membranes exhibits progressive decreases with a maximal loss of activity with age of approximately 35%. The sensitivity of this membrane-bound ion transporter to the lipid composition of the surrounding membrane, as well as the high abundance of oxidatively sensitive polyunsaturated fatty acyl chains in synaptosomal membranes, suggests that this age-related loss in catalytic turnover may result from LPO-mediated protein modification and/or changes in the physical structure of the bilayer.

Enzymatic reduction of 3-nitrotyrosine generates superoxide.

Spin-trapping with 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) was used to demonstrate that 3-nitrotyrosine (nitrotyrosine) promotes the formation of substantial amounts of reactive oxygen species (O2.- and *OH), when incubated with NAD(H)-cytochrome c reductase and a corresponding electron donor. Spin adduct formation is strongly inhibited by the presence of superoxide dismutase (SOD); spin adduct formation requires aerobic conditions.

Altered turnover of calcium regulatory proteins of the sarcoplasmic reticulum in aged skeletal muscle.

We have measured the in vivo protein turnover for the major calcium regulatory proteins of the sarcoplasmic reticulum from the skeletal muscle of young adult (7 months) and aged (28 months) Fischer 344 rats. From the time course of the incorporation and decay of protein-associated radioactivity after a pulse injection of [14C]leucine and correcting for leucine reutilization, in young rats, the apparent half-lives for calsequestrin, the 53-kDa glycoprotein, and ryanodine receptor are 5.4 +/- 0.