Wallace G. Frasher

The effects of fibrination on the in vivo rheology of dog blood

Abstract The effects of acute fibrination on the rheology of dog blood have been studied using a variable shear rate, nonpulsatile capillary viscometer; this viscometer, of special design, measures the flow properties of blood circulating in chronic exteriorized A-V shunts in dogs. Our results indicate that the concentration of fibrinogen, per se , does not influence the rheology of dog blood as measured in our instrument; the effect of plasma viscosity on the overall rheological behavior of blood is of significant importance. These conclusions are limited to the range of the independent variables studied.

Electrical conductivity method for estimating right ventricular output and mathematical model

Abstract A constant-rate injection, dilution technique for estimating right ventricular output was employed in normal dogs. Five per cent NaCl solution was injected at the right atrial-inferior vena caval junction and changes in electrical conductivity were measured from pulmonary arterial blood. There was good agreement between right ventricular output estimates with this technique and mean pulmonary arterial flow measured electromagnetically. Evidence was presented that the added indicator cleared the right atrium within one cardiac cycle, under the conditions of the experiment. A mathematical model was constructed to express the relationship of indicator concentration in pulmonary arterial blood to the indicator injection rate, the residual fraction of right ventricular blood, and the heart rate.

The use of carbethoxysyringoyl methylreserpate in hypertension

Abstract 1. (1) Single intravenous doses of carbethoxysyringoyl methylreserpate given to 2 patients with moderately severe hypertension produced a marked hypotensive effect. 2. (2) Four individuals with severe hypertension in the accelerated phase showed encouraging responses to prolonged intramuscular administration of this new drug. 3. (3) In the oral form, carbethoxysyringoyl methylreserpate can be given in relatively large doses without serious side effects. This should be of value in those patients unable to tolerate reserpine.

Special purpose intravital microscope

Abstract A special purpose intravital microscope has been constructed to allow adequate depth of throat and movement for field of view positioning for exposed tissues in moderate-sized animals. Specific adaptations are described for sequential photo-micrography and transepithelial clearance of radioisotope in defined areas of cat mesentery.

A Variable Shear Rate Capillary Viscometer for Outflow Viscometry in Dogs

Previous investigations (1,2) using an in vivo outflow viscometer for measuring the rheological properties of dog blood were limited to a range of shear rates controlled by the driving pressure provided by the experimental animal. In order to obtain a system in which shear rate (as determined by volumetric flow rate through a capillary tube) could be both pre-determined and repeated, we have modified our original outflow viscometer to permit measurements at selected rates of flow. In addition, our earlier system (1,2) operated with pulsatile flow in the measuring capillary; the system described below provides nearly smooth, non-pulsatile flow conditions in this measurement section.