CD117-positive cells and mast cells in adult human cardiac valves--observations and implications for the creation of bioengineered grafts.

Background: There is no report to date of stem cells in human cardiac valves. We examined their possible presence, number, and distribution in valves removed at cardiac surgery from patients with a variety of underlying valve pathologies.

Methods: Grossly normal aortic and mitral valves were obtained from live heart transplant patients.

Regulation of the stepwise proteolytic cleavage and secretion of PDGF-B by the proprotein convertases.

Platelet-derived growth factor-B (PDGF-B) is important for normal tissue growth and maintenance and its overexpression has been linked to several diseases, including cancer, fibrotic disease and atherosclerosis. Here, we show that synthesized as a precursor, proPDGF-B is converted to a mature form by proteolytic cleavage at two sites and its N-terminal cleavage is a prerequisite for processing at its C-terminus. The first cleavage occurs at residues RGRR81/, and the second cleavage close to residues ARPVT190, just before the C-terminal amino-acid sequence crucial for PDGF-B retention to cell surface.

Intranuclear rodlets in the substantia nigra: interactions with marinesco bodies, ubiquitin, and promyelocytic leukemia protein.

There is growing appreciation that the nucleus is organized into an array of discrete structural domains, each subserving a specific function. These functional nuclear bodies are to be distinguished from pathological intranuclear inclusions which have been described in a variety of neurodegenerative diseases. Marinesco bodies (MBs) are eosinophilic ubiquitinated intranuclear inclusions found in pigmented neurons of the human substantia nigra and locus coeruleus.

Implications of proprotein Convertase 5 (PC5) in the arterial restenotic process in a porcine model.

Introduction: Convertases (PCs), especially PC5, have been detected in various layers of atherosclerotic and injured arteries. We postulate that PCs could be important enzymes in vascular disease thus studied PC5 expression in a porcine balloon and stent coronary arterial vascular injury model.

Methods: Immunohistochemistry and in situ hybridization of slides of porcine arteries from paraffin blocks were studied 1, 7, 14 and 28 days post injury.