Biomedical subjects

K Malott

Publications and source records attributed to K Malott.

3 recordsLinked to original sources

PubMed2001

The relationship between tracheal width and left bronchial width: Implications for left-sided double-lumen tube selection.

OBJECTIVE: To determine if there is a relationship between tracheal width (TW) and left bronchial width (LBW). DESIGN: Three-dimensional chest computed tomography (CT) scans were used to reconstruct major airways for measurement of TW and LBW. SETTING: Stanford University Medical Center, Stanford, California. PARTICIPANTS: Thirty-one adult patients undergoing chest CT scans. INTERVENTIONS: Cursors were used to directly measure internal diameter from coronal images of the trachea at midclavicular level and the left main bronchus at a level 1 cm below the carina. MEASUREMENTS AND MAIN RESULTS: TW and LBW, but not the LBW-to-TW ratio, were significantly larger in men than in women. The LBW-to-TW ratio was consistent for men (0.75 +/- 0.09) and women (0.77 +/- 0.10). CONCLUSIONS: LBW is proportional to TW. If LBW cannot be measured directly but TW can, the ratio of LBW to TW can be used to predict LBW. An appropriate-sized left double-lumen tube can then be selected for the patient.

Adult↗

PubMed1984

Effect of dimethylthiourea on paraquat toxicity in rats.

We evaluated the utility of dimethylthiourea ( DMTU ), a hydroxyl radical scavenger, as potential therapy for paraquat poisoning. Seventy-five male Sprague-Dawley rats were divided into four groups ( DMTU -paraquat, paraquat, DMTU , control) and studied for up to 10 days. Clinical observations (dyspnea, weakness), mortality, hepatic and renal function tests, body weights, and histologic studies were performed. There was no mortality in the DMTU and control groups although various histologic and biochemical studies suggested that DMTU may be both hepatotoxic and nephrotoxic. In contrast, 74% of DMTU -paraquat rats and 39% of paraquat rats died (p less than 0.01). In addition, toxicity was clearly earlier in the DMTU -paraquat group than in the paraquat group. Hence, rather than being protective, treatment with dimethylthiourea was associated with increased mortality in paraquat-poisoned rats.

Animals↗

PubMed1973

Maintaining responding during stimulus generalization testing in extinction.

Resistance to extinction and generalization gradients were studied following training with a long-adjusting-interval schedule. One large reinforcer occurred at the end of each daily training session. Sessions varied in length from 20 sec to 42.66 min, but were usually the latter. Repeated generalization tests were subsequently conducted for these subjects and subjects trained with a more conventional short-random-interval schedule. The long-adjusting-interval schedule produced generalization gradients that were not qualitatively different from those produced by the conventional procedure. However, the advantages of the long-adjusting-interval schedule are: (1) greater resistance to extinction both within and across generalization tests and (2) more stable gradient slopes within and across tests.

Journal Article↗