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1.  Aging and Quality Control of Color LCDs for Radiologic Imaging 
Journal of Digital Imaging  2010;24(5):828-832.
Our practice has long been concerned with the effects of display quality, including color accuracy and matching among paired color displays. Three years of data have been collected on the historical behavior of color stability on our clinical displays. This has permitted an analysis of the color-aging behavior of those displays over that time. The results of that analysis show that all displays tend to yellow over time, but that they do so together. That is, neither the intra- nor inter-display color variances observed at initial deployment diverge over time as measured by a mean radial distance metric in color space (Commission Internationale d’Eclairage L’, u’, v’ 1976). The consequence of this result is that color displays that are matched at deployment tend to remain matched over their lifetime even as they collectively yellow.
doi:10.1007/s10278-010-9346-x
PMCID: PMC3180532  PMID: 20978919
Digital display; Diagnostic image quality; Diagnostic display; Monitors
2.  Integration of DICOM images into an electronic medical record using thin viewing clients. 
Over the past five years the University of Washington has created a clinical data repository. This repository combines in a distributed relational database information from multiple departmental databases (MIND). MINDscape provides a platform independent, web browser view of the MIND dataset that can easily be linked to other information resources on the network.
Images
PMCID: PMC2232165  PMID: 9929349
3.  THE MYOCARDIAL INTERSTITIUM: ITS STRUCTURE AND ITS ROLE IN IONIC EXCHANGE 
The Journal of Cell Biology  1974;60(3):586-601.
The structures present in the rabbit myocardial interstitium have been defined and quantified. Stereological methods were used for the quantification. The extracellular space contains abundant ground substance (23%) distributed in a homogeneous mat throughout the space and within the T tubules. The remainder of the space contains 59% blood vessels, 6% "empty" space, 4.0% collagen, and 7.0% connective tissue cells. The arrangement of the interstitium in relation to the myocardial cells and the capillaries has been described. In addition, the extracellular space was measured using extracellular markers: 14C sucrose (neutrally charged), 35SO4 (negatively charged), and 140La (positively charged). The La+++ space differed markedly from the other two (P << 0.001), indicating extensive binding of La+++ to polyanionic extracellular structures. Cetylpyridinium chloride, a cationic detergent specific for polysaccharides, caused precipitation of the ground substance and marked decrease in the La+++ space. This study indicates the considerable structural complexity of the interstitium. The effects of an abundant negatively charged protein-polysaccharide within the interstitium has been discussed in terms of cation exchange in arterially perfused tissue.
PMCID: PMC2109249  PMID: 4824287
4.  LANTHANUM IN HEART CELL CULTURE  
The Journal of Cell Biology  1972;54(3):441-455.
Correlation of the localization of La+++ with its effects on Ca++ exchange in cultured rat heart cells is examined with the use of a recently developed technique. 75% of cellular Ca++ is exchangeable and is completely accounted for by two kinetically defined phases. The rapidly exchangeable phase has a t ½ = 1.15 min and accounts for 1 1 mmoles Ca++/kg wet cells or 43% of the exchangeable Ca++ (cells perfused with [Ca++]o = 1 mM) Phase 2 has a t ½ = 19.2 min and accounts for 1.5 mmoles Ca++/kg wet cells or 57% of the exchangeable Ca++. 0.5 mM [La+++]o displaces 0 52 mmoles Ca++/kg wet cells—all from phase 1—and almost completely abolishes subsequent Ca++ influx and efflux The presence of La+++ in the washout converts the washout pattern to a single phase system with a t ½ = 124 min. The effects upon Ca++ exchange are coincident with abolition of contractile tension but regenerative depolarization of the tissue is maintained Electron microscope localization of the La+++ places it exclusively in the external lamina or basement membrane of the cells. The study indicates that negatively charged sites in the basement membrane play a crucial role in the E-C coupling process in heart muscle
PMCID: PMC2200282  PMID: 5044754
5.  Specific Uncoupling of Excitation and Contraction in Mammalian Cardiac Tissue by Lanthanum  
The Journal of General Physiology  1970;56(2):191-217.
Arterially cannulated rabbit interventricular septal tissue was exposed to 5–40 µM La in 2.5 mM Ca perfusate. Immediately following perfusion with La two concurrent events were consistently observed: (a) a rapid decline of active tension to a lesser steady-state value, and (b) an abrupt, release of short duration of tissue-bound Ca. The magnitude of both events was directly related to the [La]o. If the duration of exposure to La was brief, contractility returned toward normal upon return to the La-free perfusate. Elevation of [Ca]o during exposure to La counteracted its effect and induced a concurrent displacement of tissue-bound La. Cellular action potentials recorded during brief perfusion with La demonstrated that essentially normal regenerative depolarization was maintained. Analysis of the quantities of 45Ca released following exposure to 10 µM La indicated that this La-susceptible Ca was being displaced from a homogeneous pool—the one previously shown by Langer to represent contractile dependent Ca. These data led to the following conclusions: During perfusion with 2.5 mM Ca contractile dependent Ca was derived primarily from "superficially" located sites. La effected the release of contractile dependent Ca by modifying the normal permselectivity of this "superficial" membrane for activator Ca. These and other data infer that contractile dependent Ca is derived primarily from superficially located sites.
PMCID: PMC2225861  PMID: 5433467
6.  Xmnl polymorphism in the human TPA gene 
Nucleic Acids Research  1990;18(17):5326.
Images
PMCID: PMC332198  PMID: 1976243
8.  The Effects of Temperature upon Contraction and Ionic Exchange in Rabbit Ventricular Myocardium  
The Journal of General Physiology  1968;52(4):682-713.
The mechanical responses (active and resting tension, dP/dt, TPT) and ionic exchange characteristics (Ca++, K+, Na+) which follow upon a variation in temperature, rate, and [K+]0 were studied in the rabbit papillary muscle and arterially perfused rabbit interventricular setpum. Abrupt changes in temperature provided a means of separating the contributions of rate of development (intensity) of active state and duration of active state to total active tension development (approximated by isometric tension). Threefold changes in duration of active state with proportional changes in active tension can be induced without evidence for alteration of Ca++, K+, or Na+ exchange. Abrupt cooling produced a moderate (∼15%) increase of dP/dt which suggests an augmentation of active state intensity. Evidence is presented to suggest that this increase of dP/dt is based upon an increase in membrane Ca++ concentration which occurs secondary to inhibition of active Na+ transport. The alterations in ionic exchange and active state produced by variation of temperature are discussed in terms of a five-component control system.
PMCID: PMC2225834  PMID: 5682487
9.  The Effects of Temperature upon Contraction and Ionic Exchange in Rabbit Ventricular Myocardium  
The Journal of General Physiology  1968;52(3):682-713.
The mechanical responses (active and resting tension, dP/dt, TPT) and ionic exchange characteristics (Ca++, K+, Na+) which follow upon a variation in temperature, rate, and [K+]o were studied in the rabbit papillary muscle and arterially perfused rabbit interventricular setpum. Abrupt changes in temperature provided a means of separating the contributions of rate of development (intensity) of active state and duration of active state to total active tension development (approximated by isometric tension). Threefold changes in duration of active state with proportional changes in active tension can be induced without evidence for alteration of Ca++, K+, or Na+ exchange. Abrupt cooling produced a moderate (∼15%) increase of dP/dt which suggests an augmentation of active state intensity. Evidence is presented to suggest that this increase of dP/dt is based upon an increase in membrane Ca++ concentration which occurs secondary to inhibition of active Na+ transport. The alterations in ionic exchange and active state produced by variation of temperature are discussed in terms of a five-component control system.
PMCID: PMC2225827  PMID: 19873639
10.  Sodium Exchange in Dog Ventricular Muscle  
The Journal of General Physiology  1967;50(5):1221-1239.
Sodium exchange was studied in the arterially perfused papillary muscle of the dog. Three kinetically defined phases accounted for all the myocardial sodium: phase 0 (vascular)-λo (exchange constant) = 3.6 min-1 phase 1 (interstitial)-λ1 = 0.62 min-1; phase 2 (intracellular)-λ2 < 0.020 min-1 in quiescent muscles. The phase 2 exchange rate was proportional to frequency of contraction and increased by approximately 0.004 min-1 for each 1 beat/min increment in rate in muscles demonstrating stable function. A sudden increase in frequency of contraction was followed by a marked increase in phase 2 sodium exchange if muscle function did not deteriorate. This increased exchange required 14 min to achieve a steady state. During this time active tension increased (positive staircase) and then declined to become stable as the sodium exchange stabilized. In muscles in which increased frequency of contraction produced a progressive decrease in active tension and contracture, sodium exchange failed to increase. The characteristics of sodium exchange are compared to those previously defined for calcium and potassium in the perfused dog papillary muscle. It is proposed that alteration in sodium exchange is a primary determinant of calcium and potassium movements and thereby plays a significant role in the control of myocardial contractility.
PMCID: PMC2225707  PMID: 6033583
11.  Calcium Flux in the Mammalian Ventricular Myocardium 
The Journal of General Physiology  1963;46(4):703-719.
The exchange of Ca45 was studied in dog myocardium by means of a newly developed perfusion technique whereby an excised papillary muscle was perfused through its own artery. This makes possible the sequential and simultaneous correlation of ionic flux with ventricular myocardial function with each muscle serving as its own control. Calcium exchange has the following characteristics: (a) The major component of calcium flux is independent of the frequency of contraction. It demonstrates a rapidly equilibrating phase (half-time, 4 to 6 minutes) and a more slowly equilibrating phase with a progressively decreasing rate constant. The flux characteristics of the more rapidly equilibrating compartment are determined by a factor or factors, in addition to simple diffusion, which increase the time required for this compartment to achieve a steady-state with respect to the vascular compartment. (b) A lesser component of exchange is stimulus-rate dependent and is characterized by an alteration in the rate of calcium turnover such that the altered influx: efflux ratio requires 20 to 25 minutes to achieve equilibrium. After this time, despite the higher stimulus rate, there is no evidence of change in total tissue calcium. (c) The initial rate of the transient response is approximately proportional to the change in stimulus rate.
PMCID: PMC2195289  PMID: 13928608

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