We compared the density of dihydropyridine (DHP) receptor sites with the density of functional L-type calcium channels in ventricular myocytes from chick heart at embryonic day 11. DHP receptors were quantified by using the DHP antagonist (+)-[3H]PN200-110 and by competition binding with the agonist Bay K 8644. The number of agonist and antagonist binding sites per ventricle was similar (250 +/...

OBJECTIVES This analysis was aimed at assessing the benefits of total calcium intake from diet and supplements on both femoral neck and lumbar vertebral bone mineral density (BMD) in a representative sample of older U.S. women and men. DESIGN For 1384 women and men aged 50-70 and 71+ yr, quintiles of total calcium intake were tested for their association with hip and spine BMD after adjusting...

PURPOSE The aim of this study was to determine the causes and rate of failure in removing calcification in microcalcification-only lesions using 11-gauge stereotactic vacuum-assisted breast biopsy. MATERIALS AND METHODS In total, 1365 microcalcification-only lesions were included in this study. The breast biopsy database was reviewed retrospectively. The biopsies were divided into two groups ...

1. Serial measurements of total body calcium have been made by prompt gamma-neutron activation analysis in 13 patients with inflammatory bowel disease over a mean period of 23 months. Changes in spinal trabecular bone mineral density and radial shaft bone mineral content were also assessed by using quantitative computed tomography and single photon absorptiometry, respectively. 2. The mean annu...

Calcium induced chloride currents were studied in Xenopus oocytes using the two-electrode voltage clamp technique. Fluctuations of chloride currents measured under voltage clamp were elicited by acetylcholine. Fluctuations were superimposed on a larger chloride current. These chloride currents are due to an increase of intracellular calcium. However, an injection of calcium into the cytoplasm e...

Rim is a multi-domain, active zone protein that regulates exocytosis and is implicated in vesicle priming and presynaptic plasticity. We recently demonstrated that synaptic defects associated with loss of Caenorhabditis elegans Rim (termed UNC-10) are accompanied by a reduction in docked vesicles adjacent to the presynaptic density. Since Rim is known to interact with the vesicle-associated GTP...

Immature skeletal muscle cells, both in vivo and in vitro, express a high density of T type calcium current and a relatively low density of the dihydropyridine receptor, the protein thought to function as the Islow calcium channel and as the voltage sensor for excitation-contraction coupling. Although the role of the voltage sensor in eliciting elevations of myoplasmic, free calcium (calcium tr...

Anthropologically speaking, humans were high consumers of calcium until the onset of the Agricultural Age, 10,000 years ago. Current calcium intake is one-quarter to one-third that of our evolutionary diet and, if we are genetically identical to the Late Paleolithic Homo sapiens, we may be consuming a calcium-deficient diet our bodies cannot adjust to by physiologic mechanisms. Meta-analyses of...

Proefschrift ter verkrijging van de graad van doctor aan de Radboud Universiteit Nijmegen op gezag van de rector magnificus prof. mr. General Introduction 9 Calcium signaling in control of life and death 10 Release and uptake of calcium from subcellular organelles 11 Influx and efflux of calcium from the extracellular medium and the cytoplasm 13 Role of the membrane potential in cellular signal...

The mechanism of the calcium-catalyzed coupling alcohols with vinylboronic acids has been analyzed by means density functional theory computations. This study reveals that calcium and boron Lewis associate to form a superelectrophile able promote pericyclic group transfer reaction allyl alcohols. With other alcohols, two act synergistically activate OH functionality trigger SNi pathway. These m...