Similar to its role in secretory cells, calcium triggers exocytosis in nonsecretory cells. This calcium-dependent exocytosis is essential for repair of membrane ruptures. Using total internal reflection fluorescence microscopy, we observed that many organelles implicated in this process, including ER, post-Golgi vesicles, late endosomes, early endosomes, and lysosomes, were within 100 nm of the...

Calcium ions have been increasingly implicated as a mediator of the mechanisms generating lethal cell injury under a variety of pathologic circumstances. An overview of the various roles suggested for such alterations in cellular calcium homeostasis is presented. The central role of plasma membrane damage in the genesis of irreversible cell injury is used to divide the postulated roles for calc...

Plant freezing tolerance involves the prevention of lethal freeze-induced damage to the plasma membrane. We hypothesized that plant freezing tolerance involves membrane resealing, which, in animal cells, is accomplished by calcium-dependent exocytosis following mechanical disruption of the plasma membrane. In Arabidopsis thaliana protoplasts, extracellular calcium enhanced not only freezing tol...

The plume generated by ablation of hydroxyapatite targets under ArF excimer laser irradiation has been investigated by means of fast intensified charge coupled device (CCD) imaging and optical emission spectroscopy. Results have shown that the plume splits into two plasma clouds as it expands. Time and spatial resolved spectra have revealed that under the experiment conditions emission is mostl...

PURPOSE Vitamin D deficiency impairs bone mineralisation and can predispose individuals to fractures. This study aimed at testing whether measurement of plasma calcium, alkaline phosphatase, and phosphate levels could detect vitamin D insufficiency. METHODS During a 10-week winter period from December 2000 to February 2001, all elderly patients presenting to a general hospital in Brighton--Br...

PURPOSE The series of experiments described were undertaken to evaluate the use of a cell-free lysis model to measure membrane fusion events in photoreceptor rod outer segments (ROS). The experiments measure fusion initiated with the osmotic disruption of fluorescenty-labeled ROS and correlate these findings with previously described disc-plasma membrane fusion. The influence of calcium and dis...

Keywords: angiotensin-converting enzyme; hyper-hyperplasia, although the signal was particularly intense in the region of the left lower gland. calcaemia; hyperparathyroidism; parathyroidectomy; The patient was referred for surgical parathyroidec-parathyroid hormone; sarcoidosis tomy. Four glands were identified, all of which appeared enlarged. Three whole glands plus a section of the fourth gl...

CD20 is a B-lymphocyte-specific integral membrane protein, implicated in the regulation of transmembrane calcium conductance, cell-cycle progression and B-lymphocyte proliferation. CD20 is proposed to function as a SOCC (store-operated calcium channel). SOCCs are activated by receptor-stimulated calcium depletion of intracellular stores. Sustained calcium conductivity across the plasma membrane...

Nineteen very low birthweight (mean (SD) gestational age 28 (3) weeks) were parenterally fed nutrition solutions containing inorganic calcium and phosphorus salts. All infants had hypophosphataemia. Plasma concentrations were maintained between 1.5 mmol/l and 2.2 mmol/l. Plasma phosphorus concentrations reached 1.5 mmol/l or greater in three patients after 12 hours, in a further nine patients a...