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Biomedical subjects

D C Knight

Publications and source records attributed to D C Knight.

7 recordsLinked to original sources
PubMed1986

Aspiration of the breast and nipple discharge cytology.

Between 1 January 1974 and 30 June 1984, 1,003 specimens obtained from the breast were submitted for cytologic evaluation to the Department of Pathology at the Waterbury Hospital Health Center. Eighty-eight per cent were obtained by fine needle aspiration of a palpable mass; the remainder were smears of nipple discharges. Precytologic and postcytologic clinical data were available for 80 per cent of the specimens. In the fine needle aspiration group, there were 219 instances of proved carcinomas; 79 per cent of these had either positive or suspicious cytologic findings. Seventy-five per cent of the patients with positive cytologic results underwent mastectomy without prior histologic confirmation of the needle aspiration and all were confirmed as malignant growths. There were 41 false-negative aspirates which were reviewed in detail. The cytologic slides of 24 of the 41 false-negative aspirates were available for re-evaluation by a second, independent cytopathologist. Only one was thought to have been misread initially; the remainder appeared to have been falsely negative for technical reasons related to aspiration or fixation technique or tumor size less than 1 centimeter. There was one false-positive finding in a patient who was found to have fat necrosis at biopsy. Results of nipple discharge cytology were less accurate. Positive or suspicious cytology was found in only five of 11 proved instances of carcinomas. There was one false-positive and five false-negative results in this group. We conclude that needle aspiration of palpable masses of the breast is an accurate, cost effective procedure which is readily adaptable to a community hospital, provided that a pathologist with an interest in cytology is available.

Adolescent↗
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↗