In stimulated platelets phosphatidylinositol is degraded by a phosphatidylinositol-specific phospholipase C to 1,2-diacylglycerol which is then phosphorylated to phosphatidic acid. Thrombin stimulation of horse and human platelets prelabeled with [32P]orthophosphate induces the formation of [32P]lysophosphatidylinositol, suggesting that phosphatidylinositol is also degraded by a phospholipase o...

In Escherichia coli, a two-component signal transduction system, consisting of the transmembrane sensor protein ArcB and its cognate cytoplasmic regulatory protein ArcA, controls the expression of genes encoding enzymes involved in aerobic respiration. ArcB belongs to a subclass of sensors that have not only a conserved histidine-containing transmitter domain but also a conserved aspartate-cont...

The histologic effects of a contact ultrasound applicator were compared with those of the immersion applicator that is currently used clinically for the treatment of glaucoma. The applicator coupling cone uses a distensible rubber membrane that can be inflated to control stand-off distance relative to the surface of the eye. This feature allows the focal point of the therapeutic beam to be plac...

Platelet-derived endothelial cell growth factor (PD-ECGF) is a 45-kDa peptide mitogen which is present in platelets and placenta and produced by certain cultured cell lines. Immunoprecipitation of A431 cells metabolically labeled with [32P]orthophosphate revealed the incorporation of 32P radioactivity into PD-ECGF. Phosphoamino acid analysis showed that serine residues of PD-ECGF were phosphory...

The uptake of [32P]phosphate by human, gel-filtered blood platelets and its incorporation into cytoplasmic ATP and polyphosphoinositides was studied. In unstimulated platelets, uptake was Na+o-dependent and saturable at approximately 20 nmol/min/10(11) cells with a half-maximal rate at 0.5 mM extracellular phosphate. Upon stimulation with thrombin or collagen, net influx of [32P]Pi was accelera...

Learning objectives Discuss the role and benefits of MRI in planning for brachytherapy treatment in cervical cancer. Discuss the key mechanisms of the applicator and the technical aspects of planning brachytherapy. Discuss the role of MRI imaging in recognising the features of appropriate applicator placement and common complications. Review key MRI features of radiation-related alterations in ...

Background: The dose rate distribution delivered by a low dose rate 137Cs pellet source, a spherical source used within the source trains of the Selectron gynecological brachytherapy system, was investigated using the MCNP4C Monte Carlo code. Materials and Methods: The calculations were performed in both water and Plexiglas and the absolute dose rate distribution for a single pellet s...