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Biomedical subjects

L J Dunegan

Publications and source records attributed to L J Dunegan.

6 recordsLinked to original sources
PubMed1976

Angiosarcoma of the breast: a report of two cases and a review of the literature.

Angiosarcoma of the breast, a rare tumor with very poor prognosis and insidious early manifestations, frequently is far advanced when first detected clinically. The clinical and pathologic changes in two women with primary, unilateral angiosarcoma of the breast are reviewed and the results are compared with 46 cases already published in the literature. Both patients were middle aged with symptoms for approximately 6 months prior to operation. Both frozen section reports were benign and only called malignant on permanent section. Microscopically the tumors were composed of varying sized, tortuous, elongated vascular channels. The operation varied--a modified radical and a simple mastectomy--and both patients are free from disease 4 and 2 years following operation. It is considered that, in view of the proclivity of this tumor for hematogenous metastases, an axillary dissection may not be justified.

Adult↗
PubMed1975

Lung thermal volume in pulmonary edema: effect of positive end expiratory pressure.

Effects of intermittent (IPPB) and positive eng-expiratory pressure (PEEP) ventilation on accumulation of pulmonary edema were compared, in dogs, after infusion of oleic acid. Pulmonary extravascular water was approximated as lung thermal volume (LTV), a double indicator method based on differential transit time for simultaneously injected right-to-left conductivity and thermal pulses. LTV was found to be decreased in animals treated with PEEP. The possibility that observed LTV changes reflect only the effect of PEEP on flow distribution, not lung water, was examined by alternating PEEP and IPPB; short-term changes in LTV did not occur. Mean values of other factors influencing pulmonary water transfer, e.g., pulmonary capillary wedge pressure, serum protein, arterial blood gasses, were not significantly different with or without PEEP. It was concluded that, for the oleic acid lesion, PEEP effects a small reduction in the rate of accumulation of pulmonary edema.

Animals↗
PubMed1975

Rapid estimation of pulmonary extravascular water with an instream catheter.

An arterial catheter-bearing external conductivity electrodes and a thermistor was used for measurement of lung thermal volume (LTV) by the double-indicator method. Ten milliliters of 3% saline at room temperature were injected, dilution curves measured, and LTV calculated as mean transit time difference, less thermistor time constant, times cardiac output (CO). Comparisons were made, in dogs, between LTV, pulmonary extravascular lung water with Evans blue and tritiated water (PEVWtho), and weighed lung water (WLW). Pulmonary edema was induced with dextran and epinephrine. CO was measured by thermodilution in both the pulmonary artery (PA) and aorta (AO) and dye dilution in the AO. CO from dye dilution was compared with thermodilution (aortic detection) to detect irreversible loss of thermal indicator. Comparisons showed good correspondence of dye and thermal curves (Y = 0.91X - 0.16 1/min; r = 0.93). LTV is about 120% of WLW in near normal lungs, 90% of WLW in extreme edema. PEVWtho was 60-70% WLW.

Animals↗
PubMed1975

Pulmonary insufficiency induced by oleic acid in the sheep: a model for investigation of extracorporeal oxygenation.

Most previous studies of the efficiency of bypass techniques for respiratory support have been conducted in hypoxic but otherwise normal animals. However, mechanisms of improved oxygenation by partial venoarterial bypass in the presence of acute respiratory insufficiency can be better studied with an appropriate pathophysiologic model; for this purpose, acute hemorrhagic pulmonary edema was induced in sheep by injection of oleic acid into the right atrium. The model presented a 3 hour period of elevated pulmonary shunting with stable hemodynamics. This preparation is being employed to the study of the mechanisms of extracorporeal oxygenation.

Animals↗