Comparative microvascular exchange kinetics of [(77)Br]bromide and (99m)Tc-DTPA in humans.

The plasma clearance curves of small hydrophilic solutes comprise three exponentials, consistent with a three-compartmental distribution model. A previous comparison between inulin and diethylene triamine penta-acetic acid (DTPA) suggested that these three compartments are in series, the first being plasma and the second and third representing compartments within the extravascular space. Moreover, whilst the total distribution volumes of these two indicators were similar, the volume of the second compartment was higher for DTPA.

Morphology of Nurse Cell Nuclei Induced by Meloidodera floridensis: A Graphics Application.

The highly irregular distribution of nuclear material in the host nurse cell induced by Meloidodera floridensis has made it difficult to interpret the number of nuclei from two-dimensional micrographs alone. The primary goal of this investigation was to determine the distribution of nuclear material from a three-dimensional solid surface model of the nurse cell nucleus. This model demonstrated the continuity of nuclear material as a single highly irregular nucleus.

The influence of tissue depth and composition on the performance of the Lunar dual-energy X-ray absorptiometer whole-body scanning mode.

To assess the performance of the Lunar dual-energy X-ray absorptiometer (DPX) whole-body scanning mode (software version 3.1), a simple phantom was devised. This had known but variable amounts of lard to represent fat, and water to represent fat-free tissue.

Comparative performance in vitro and in vivo of Lunar DPX and Hologic QDR-1000 dual energy X-ray absorptiometers.

The measured absolute bone mineral density values of spine and femur and their precision were compared on two dual energy X-ray absorptiometers, the Lunar DPX and the Hologic QDR-1000. There were systematic differences between the two systems, the Lunar DPX always giving a higher bone density value. The ratio of the mean Lunar DPX/Hologic QDR-1000 bone density measurements obtained in vivo was 1.

Glucocorticoid regulation of rat diencephalon angiotensinogen production.

To investigate whether glucocorticoids can stimulate rat brain angiotensinogen production directly, we have studied the effect of dexamethasone on angiotensinogen secretion and angiotensinogen mRNA concentration in primary astroglial cultures from rat diencephalon. Dexamethasone stimulated angiotensinogen secretion by astroglial cells in a dose-related fashion. The half-maximally effective concentration was 11 nM, and the effect was blocked by RU 486, an antagonist of type II glucocorticoid receptors.