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Biomedical subjects

W M Yudt

Publications and source records attributed to W M Yudt.

8 recordsLinked to original sources

Renal hemodynamic response to the creation of vascular access in patients with end-stage renal disease.

To evaluate the possibility that the placement of arteriovenous anastomosis (a/v a) may lead to the attenuation of glomerular hyperfiltration, we studied 5 nondiabetic patients before and after creation of vascular access for hemodialysis. Patients received no EPO and antihypertensive therapy was discontinued 24 h before each study. Cardiac output (CO) and a/v a flow rates were measured by Doppler echo, and GFR and ERPF by plasma decay curves of Tc99m DTPA and 131I-hippuran, respectively. Other parameters were calculated by standard formulas. Augmentation of CO and decrease in systemic vascular resistance occurred in all patients (p = 0.05), yet renal findings were less predictable since only three patients showed a decrease in renal vascular resistance and filtration fraction post a/v a. Thus, there is a discordant pattern of renal hemodynamic response to the creation of a/v a in end-stage renal disease and further studies are needed to better define the subset of patients who are prone to renal vasodilation after the placement of a/v a.

Adult↗

Scintigraphic detection of hemobilia complicating angiodysplasia.

A 78-yr-old man underwent 99mTc-labeled red cell examination for a gastrointestinal bleeding episode. Gallbladder visualization was noted during the examination. Hemobilia has been reported in a variety of pathologic conditions; scintigraphic gallbladder visualization has also been reported as a result of the unusual radiolabeling characteristics of 99mTc during red cell scintigraphy. Postmortem examination revealed angiodysplasia of the gallbladder and other sites in the gastrointestinal tract. Angiodysplasia must be considered in the pathologic spectrum of causes of hemobilia.

Aged↗

Superior vena cava obstruction in fibrosing mediastinitis: demonstration of right-to-left shunt and venous collaterals.

Multiple venous collateral pathways have been described in patients with superior vena cava obstruction. Systemic venous-to-pulmonary venous communication is the most unusual, having been described in a few cases of thoracic malignancy. In a patient with fibrosing mediastinitis radionuclide venography with 99Tcm-macroaggregated albumin demonstrated a systemic venous-pulmonary venous right-to-left shunt in addition to systemic and portal venous collaterals. It is apparent that systemic venous-to-pulmonary venous anastomoses may occur in the absence of malignant disease.

Adult↗

Axillary iodine-131 accumulation due to perspiration.

A case of spurious axillary uptake of I-131 proven to be caused by perspiration is presented. False-positive localizations of radioiodine, both pathologic and physiologic, are reviewed to avoid confusion of these entities with functioning thyroid carcinoma metastases.

Adult↗

Hyperthyroidism and the single lobe.

A practical approach to the hyperthyroid patient with a single lobe visualized on thyroid scintigraphy, and its impact on therapy is discussed. An illustrative case is also presented.

Adenoma↗

Indium-111 chloride imaging with ununited fractures.

Twenty patients with ununited fractures and a suspicion of infection had In-111 chloride imaging. Surgically obtained cultures were positive for infection in 12 and negative in eight patients. In-111 chloride images were positive in all 12 patients with infection but also were positive in six of the patients with negative cultures. It is not possible to differentiate infected from noninfected ununited fractures by In-111 chloride imaging.

Fractures, Ununited↗