Objective—Protein Kinase C delta (PKC ) is expressed in platelets and activated downstream of protease-activated receptors (PAR)s and glycoprotein VI (GPVI) receptors. The purpose of this study was to investigate the role of PKC in platelets. Methods and Results—We evaluated the role of PKC in platelets using two approaches—pharmacological and molecular genetic approach. In human platelets pret...

Even though platelets are known to play a critical role in hemostasis, mediated in part by their uptake, storage, and release of serotonin, there are many unexplored aspects of this process. Herein, single-cell amperometry is employed to characterize the dynamic secretion of serotonin from platelet dense-body granules. On the basis of a three-dimensional random walk simulation that estimates de...

NF-κB is an integral component of the immune response to Toxoplasma gondii. Although evidence exists that T. gondii can directly modulate the NF-κB pathway, the parasite-derived effectors involved are unknown. We determined that type II strains of T. gondii activate more NF-κB than type I or type III strains, and using forward genetics we found that this difference is a result of the polymorphi...

Platelet secretion not only drives thrombosis and hemostasis, but also mediates a variety of other physiological and pathological processes. The ubiquitous SNARE machinery and a number of accessory proteins have been implicated in regulating secretion in platelet. Although several platelet SNAREs have been identified, further members of the SNARE family may be needed to fine-tune platelet secre...

BACKGROUND Protein kinase C (PKC) is a major regulator of platelet function and secretion. The underlying molecular pathway from PKC to secretion, however, is poorly understood. By a proteomics screen we identified the guanine nucleotide exchange factor cytohesin-2 as a candidate PKC substrate. OBJECTIVES We aimed to validate cytohesin-2 as a PKC substrate in platelets and to determine its ro...

The intracellular development of three pox viruses has been studied with the electron microscope using thin sections of infected tissue. Cells infected with vaccinia, ectromelia, and molluscum contagiosum viruses all form developmental bodies preliminary to the production of mature virus. Developmental bodies, believed to be virus precursors, are round to oval, slightly larger than mature virus...

Objective—To better understand the mechanism of platelet recruitment and activation by Streptococcus gordonii. The oral bacterium Streptococcus gordonii, is amongst the most common pathogens isolated from Infective Endocarditis patients, and has the property of being able to activate platelets, leading to thrombotic complications. The mechanism of platelet recruitment and activation by S. gordo...

The origin, nature, and distribution of polymorphonuclear leukocyte (PMN) granules were investigated by examining developing granulocytes from normal rabbit bone marrow which had been fixed in glutaraldehyde and postfixed in OsO(4). Two distinct types of granules, azurophil and specific, were distinguished on the basis of their differences in size, density, and time and mode of origin. Both typ...