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Biomedical subjects

S W Miller

Publications and source records attributed to S W Miller.

86 records · Page 5Linked to original sources
PubMed1975

Significance of renewal asymmetry in bone scans: experience in 795 cases.

A retrospective study of 795 consecutive bone scans employing either 18F or 99mTc-pyrophosphate to evaluate the diagnostic value of renal asymmetry in such scans has been carried out. It is concluded that asymmetric renal images in bone scans convey relatively specific information regarding renal pathology, especially in the 99mTc-pyrophosphate studies.

Adenocarcinoma↗
PubMed1974

Calcification in uroepithelial tumors of the bladder. Report of 5 cases and survey of the literature.

Roentgenologic calcification of transitional and squamous cell cancers of the bladder is an uncommon but certainly not rare finding: in this and another large series it occurs in approximately 0.5 per cent of cases. The tumors tend to be large, and the calcium may be encrusted on the surface of the neoplasm or lie deeper in a subepithelial position in degenerating or necrotic areas. Pathologically, the scattered or conglomerate distribution of the calcium results in a roentgenologic granular or nodular appearance usually in a semicircular pattern involving only a portion of the tumor mass as determined by urography or cystography. Bladder tumor calcification is sufficiently distinct to be differentiated from other more common calcifications occurring in the pelvis.

Aged↗
PubMedDate not supplied

Computerized tomography of ischemic myocardium: quantitation of extent and severity of edema in an in vitro canine model.

The capacity of computerized tomography to assess myocardial edema resulting from acute coronary occlusion was investigated in 19 arrested and 2 beating canine hearts. Edematous myocardium was consistently detected as areas of decreased attenuation values. The magnitude of the decrease in attenuation value was linearly related to the severity of the edema. The anatomic definition and tomographic information in the arrested hearts provided the capability for localization and quantitation of the extent of the lesion. The results of these in vitro investigations indicate that CT scanning is a technique which will contribute important pathophysiologic information about the evolution of myocardial ischemia.

Animals↗
PubMedDate not supplied

Effects of radiographic contrast material on cultured myocardial cells.

Radiographic contrast material in doses commonly used in clinical practice produces major alterations in cardiac rhythm. In order to separate the direct cellular effect of the constituents of contrast material from the indirect actions of neural and hormonal mediators, a tissue culture technique was developed using newborn rat heart cells. The rate of contraction of both individual cells and of a syncytium of cells decreased and became briefly asystolic after contrast material was added to the media, then recovered with varying degrees of arrhythmia. Cells in culture less than one week showed significantly fewer arrhythmias and less recurrent asystole after contract material than older cells (P less than 0.05). Cells pretreated with pharmacologic amounts of atropine (0.08 microgram/ml), ouabain (0.02 microgram/ml), lidocaine (16 microgram/ml), and quinidine (20 microgram/ml) continued to demonstrate the initial asystole, although quinidine and lidocaine diminished the frequency of arrhythmias in the recovery stage. Hyperosmolar dextrose produced asystole, as did Renografin-60, Hypaque-50, and Conray only at concentrations greater than 1000 mOsm, suggesting that an osmolarity threshold may exist for the production of asystole. Less fibrillation occurred when the sodium and calcium ionic concentrations of contrast material were adjusted to that of plasma, although the arrhythmias could not be eliminated. Renografin-60, containing the greatest amount of calcium-chelating agents, produced a significantly greater degree of terminal asystole (P less than 0.05), which was reversible upon addition of CaCl2. Thus, contrast material produces a decrease in the rate of contraction in cultured cardiac cells in the absence of neural and hormonal mediators. The evoked arrhythmias are dependent upon the osmolality and ionic sodium and calcium concentrations.

Animals↗