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Biomedical subjects

W Gries

Publications and source records attributed to W Gries.

5 recordsLinked to original sources
PubMed1995

Volume estimation of multicellular colon carcinoma spheroids using Cavalieri's principle.

Multicellular tumour-spheroids are regarded as suitable models for cancer research, similar to avascular tumour parts. As a size parameter of the spheroids, usually their maximum diameter is used, estimated on a section presumed to be equatorial or near equatorial. Estimation of the volume of spheroids is of interest for the detection of subtle changes in different kinds of investigations. Since spheroids are often not truly spherical, and because model-based methods for volume determination may be biased, Cavalieri's principle, rediscovered recently for stereology, was used to determine the volume of the spheroids. Here we report the results of the volume estimation of colon carcinoma spheroids, together with an outline of the basic stereological principle and formulas used. The spheroids investigated had a volume between 1.4 and 92.3 mm3 (mean 33.9). The volume fraction of necrotic to viable tissue cells was between 0.6:1 and 2.2:1. The coefficient of error (CE) was remarkably low with 3.7% for the volumes. Both inter- and intraobserver-variability were extremely low with correlation coefficients (r2) of 99%. Thus, the high precision of the stereological method, combined with a low workload, make it ideally suitable for routine volume estimation.

Carcinoma↗
PubMed1988

Coronary angiography during acute myocardial infarction in dogs: comparison of the hemodynamic effects of ionic and nonionic contrast media.

We compared the hemodynamic effects during coronary angiography of three nonionic contrast media, iopamidol, iohexol, and ioversol, with each other as well as with the standard ionic contrast medium containing 66% diatrizoate meglumine and 10% diatrizoate sodium (Hypaque-76) in the presence of a left anterior descending coronary artery occlusion in dogs. In 13 opened-chest anesthetized dogs, we recorded the maximal change in left ventricular systolic pressure (LVSP), mean aortic pressure (MAP), left ventricular diastolic pressure (LVDP) and rate of rise in left ventricular pressure (LV dp/dt) during left main coronary artery injections of 10 ml each of Hypaque-76, iopamidol, iohexol, and loversal 1 hour after left anterior descending coronary artery occlusion. The changes in LVSP and MAP were, respectively, -29 +/- 12 mm Hg and -21 +/- 11 mm Hg with Hypaque-76, 3 +/- 6.6 mm Hg and -0.2 +/- 3.6 mm Hg with iopamidol, 4.8 +/- 8.6 mm Hg and 0.5 +/- 4 mm Hg with iohexol, and -0.8 +/- 6 mm Hg and -1.5 +/- 33 mm Hg with ioversal (p less than 0.001). The change in LVDP was 5.4 +/- 4.4 mm Hg with Hypaque-76 but -1.5 +/- 3.1 mm Hg with iopamidol, -1.7 +/- 2.4 mm Hg with iohexol, and -0.5 +/- 2.5 mm Hg with ioversol (p less than 0.001). The LV dp/dt decreased 682 +/- 318 mm Hg/sec with Hypaque-76, but increased 412 +/- 297 mm Hg/sec with iopamidol, 350 +/- 214 mm Hg/sec with iohexol, and 293 +/- 191 mm Hg/sec with ioversol (p less than 0.001). Thus, each nonionic agent produced significantly fewer hemodynamic abnormalities than Hypaque-76. There was no significant difference between any of the nonionic agents on any hemodynamic parameter. These agents may be preferable in patients with acute myocardial infarction or significantly impaired myocardial function.

Acute Disease↗
PubMedDate not supplied

Giant cell myocarditis: first report of disease recurrence in the transplanted heart.

A 51-year-old female underwent heart transplantation for endomyocardial biopsy-proved giant cell myocarditis complicated by rapidly progressive congestive heart failure unresponsive to immunosuppression. Preoperatively there was no evidence of an associated extracardiac granulomatous disease. Twenty-one months after heart transplantation, giant cell myocarditis recurred in the allograft associated with sustained ventricular arrhythmias. There remained an absence of concomitant extracardiac granulomatous diseases and infections. Increased corticosteroid therapy cleared myocardial inflammation but did not abolish ventricular arrhythmias, which required pharmacologic intervention and the insertion of an Intertach II antitachycardia pacemaker. Compared with a value of 0.56 obtained 1 year after heart transplantation, left ventricular ejection fraction decreased to 0.29 at the time of diagnosis of giant cell myocarditis and remained subnormal 6 months later. Because giant cell myocarditis can recur in the allograft, the candidacy of patients with this disease for heart transplantation must be carefully assessed.

Biopsy↗