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Biomedical subjects

B D Daly

Publications and source records attributed to B D Daly.

At least 73 records · Page 4Linked to original sources

Computed tomographic scanning of the mediastinum in the staging of bronchogenic carcinoma.

We investigated the efficacy of 2-s breath-holding computed tomographic (CT) scans and standard posteroanterior and lateral chest roentgenograms in staging the mediastinum and pulmonary hill in lung cancer. Fifty-one comparisons were made in 49 patients thought to have non-small-cell carcinoma, consecutively chosen to be free of disseminated tumor, and to be suitable candidates for thoracotomy. The CT scans accurately predicted mediastinal neoplastic lymphadenopathy in 15 or 17 instances of proved mediastinal lymph node metastasis for a sensitivity of 88%; specificity was also high (94%) with a true-negative scan in 32 of 34 instances. Standard chest roentgenograms were much less sensitive (47%) than rapid CT scanning in mediastinal staging; there were false-negative interpretations in 9 of 17 instances. Specificity of the methods was the same. both CT scans and standard chest roentgenograms had a sensitivity of only 67% in detecting neoplastic hilar adenopathy; enlarged hilar nodes were noted in only 10 of 15 patients with proved hilar node metastasis. We concluded from this preliminary study that rapid CT scanning shows promise of being useful in the noninvasive staging of the mediastinum of patients with otherwise operable non-small-cell bronchogenic carcinoma; the technique also provides useful guidance during mediastinoscopy and may detect lymphadenopathy not so visualized, but CT scanning appears to have little advantage over standard posteroanterior and lateral chest roentgenograms in staging the pulmonary hill.

Adult↗

An improved technique for coronary vascular anastomosis.

A vein holder is described that is used for anastomosis of both ends of aortocoronary bypass grafts. It minimizes handling of the graft, ensures precision in placing sutures with excellent visualization, and provides maximum patency at the anastomotic sites.

Coronary Artery Bypass↗

Dynamic alveolar mechanics as studied by videomicroscopy.

The in vivo morphology of rat alveoli has been recorded and studied on videotape. The dynamic internal structure has been compared to that observed by histologic section from lung rapidly frozen with liquid nitrogen. The irreversible nature of local alveolar wall movement has been demonstrated in animals ventilated both with and without positive end-expiratory pressure (10 cm water) by parametrically comparing the distances between two sets of paired points measured sequentially across internal alveolar surfaces at intervals of 0.017 sec. Geometric hysteresis was significantly less in the animals ventilated with positive end-expiratory pressure. This hysteresis can be explained by irreversibility in alveolar surface area apart from any irreversible dependence on surface tension. Sharp reverses and rapid changes in geometric hysteresis suggest that the length-tension properties of elastic tissue within the alveolar wall and interface forces from adjacent alveoli are important determinants of local alveolar wall motion and pulmonary hysteresis.

Animals↗

Effects of an abdominal left ventricular assist device on myocardial oxygen supply/demand ratios in normally perfused and ischemic bovine myocardium.

The effects of an abdominal left ventricular assist device (ALVAD) on subendocardial oxygen supply/demand ratios as reflected by diastolic pressure-time index/tension-time index (DPTI/TTI) were investigated in calves. Control DPTI/TTI ratios were 1.09 plus or minus 0.12 (mean plus or minus SD). With ALVAD actuation the ratios increased to 5.73 plus or minus 3.2. Following circumflex coronary artery occlusion, control ratios decreased to 0.04 plus or minus 0.05 in the ischemic area and 0.97 plus or minus 0.20 in the nonischemic areas. With ALVAD actuation in the presence of circumflex occlusion, the depressed ratios were increased to 1.37 plus or minus 0.39 in the ischemic zone and 9.71 plus or minus 2.5 in the nonoccluded segments. Subendocardial oxygen supply/demand ratios were significantly improved by ALVAD assistance following induced subendocardial ischemia.

Animals↗