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Drinking water that does not equilibrate with ruminal fluid, i.e., bypasses the rumen, was studied qualitatively and quantitatively in eight rumen-fistulated lactating Holstein cows. Decreased temperatures in the sulcus omasi and abomasum shortly after initiation of drinking indicated that water had bypassed the rumen. Recovery of a water-soluble marker,(More)
Successful hyperthermia treatment of tumors requires understanding the attendant thermal processes in both diseased and healthy tissue. Accordingly, it is essential for developers and users of hyperthermia equipment to predict, measure and interpret correctly the tissue thermal and vascular response to heating. Modeling of heat transfer in living tissues is(More)
The present communication presents a single microprobe technique for measuring tissue thermal properties based on the dissipation of a measured amount of energy and the observation of the resulting temperature rise a given time later. An advantage of this method is that the effective sampling volume can be varied by varying the measurement time. Using a(More)
A perfused tissue phantom, developed as a tool for analyzing the performance of ultrasound hyperthermia applicators, was investigated. The phantom, consisting of a fixed porcine kidney with thermocouples placed throughout the tissue, was perfused with degassed water by a variable flow rate pump. The phantom was insonated by an unfocused multielement(More)
Glutathione (GSH) is important in detoxification and regulating cyclooxygenase activity. Since the liver has high levels of GSH, xenobiotic-induced changes in hepatic GSH could affect hepatic tissue blood perfusion (HP) via alterations in prostaglandin synthesis. In anesthetized male New Zealand rabbits, elevating GSH with GSH monoethyl ester had no affect(More)
1. Renal tissue blood flow (renal perfusion) and plasma levels of arginine vasotocin (AVT) and mesotocin (MT) were measured in anesthetized chickens before and during hemorrhage. 2. Renal perfusion did not decrease (P less than 0.05) until nearly 50% of the blood volume had been removed. The decrease in renal perfusion was not related to arterial blood(More)
Using a simplified avian kidney model, renal arterial perfusion pressure (RAPP) was reduced from 120 (control) to 70 mmHg (near the glomerular filtration rate autoregulatory limit) and then to 46 mmHg (below the glomerular filtration rate autoregulatory range) in kidneys with ambient or partially restricted renal portal flow. Renal blood flow (RBF) was(More)
A simple technique for measuring thermal conductivity of biomaterials is described. The method is based on depositing a pulse of heat into the material of choice, and fitting the subsequent local temperature decay to that predicted by a theoretical model. This transient method is most suitable in situations where frequent measurements of the thermal(More)