Effect of supplementation with beta-carotene and vitamin A on lung nutrient levels.

The Carotene and Retinol Efficacy Trial (CARET), a randomized, placebo-controlled lung cancer chemoprevention trial of 30 mg of beta-carotene and 25,000 IU of retinyl palmitate, was prematurely terminated when a 46% excess lung cancer mortality was found in subjects on the active arm. Before the CARET intervention ended, 21 men were recruited to participate in a 6-month biomarker study using the same intervention as CARET that determined the effect of this supplementation on lung nutrient levels. Plasma and bronchoalveolar lavage (BAL) cell nutrient levels were measured before and after the intervention. The group in the active arm (n = 10) had plasma carotene level increases of over 10-fold, with a small increase in plasma retinol levels BAL cell levels of beta-carotene in the active group also increased 10-fold, from 4.5 to 46.3 pmol/10(6) cells (P = 0.0008), with no change in BAL cell retinol levels. Surgically obtained lung tissue from three CARET subjects in the active arm showed elevated carotene lung tissue levels but no increase in lung retinol levels compared to a group of surgical controls. Combined with our previous work showing a strong correlation between BAL and lung tissue nutrient levels, these findings suggest that supplementation with beta-carotene and vitamin A results in increased lung tissue as well as BAL cell levels of beta-carotene, with little change in lung retinol.

Ethics and communication: does students' comfort addressing: ethical issues vary by specialty team?

Ethics education aims to train physicians to identify and resolve ethical issues. To address ethical concerns, physicians may need to confront each other. We surveyed medical students to determine if their comfort challenging members of their ward teams about ethical issues varies by specialty and what attributes of students and their teams contributed to that comfort. Compared to other specialties, students felt significantly less comfortable challenging team members about ethical issues on surgery and obstetrics/gynecology. We suggest that ethics education must address the atmosphere on ward teams and give students skills to help them speak out despite their discomfort.

Characterization of carotenoid, vitamin A, and alpha-tocopheral levels in human lung tissue and pulmonary macrophages.

Increasing evidence suggests that beta-carotene, retinol (vitamin A), and alpha-tocopheral (vitamin E) may have important protective effects in the lung. However, surprisingly little is known about their storage and metabolism in human lung. Levels of beta-carotene, retinol, and alpha-tocopherol in human lung tissues and bronchoalveolar lavage (BAL) cells were determined with reverse-phase high-pressure liquid chromatography (HPLC). Fresh lung tissue, serum, and dietary questionnaires were obtained from 21 patients undergoing open lung surgery, and BAL cells from 12 of these patients. Dietary and serum levels of carotenoids, beta-carotene, retinol, and alpha-tocopherol were consistent with previously reported values. Lung tissue levels of total carotenoids, beta-carotene, retinol, and alpha-tocopherol were respectively 0.34 +/- 0.36 microg/g, 0.13 +/- 0.27 microg/g, 0.15 +/- 0.06 microg/g, and 9.60 +/- 4.86 microg/g tissue. Levels of these nutrients were also measured in BAL cells to establish potential markers for their lung tissue levels. Correlations between serum, BAL-cell, tissue, and dietary levels of the nutrients were determined. Lung tissue levels of total carotenoids, beta-carotene, and alpha-tocopherol, but not retinol, correlated well with their serum levels. Lung tissue levels of retinol and alpha-tocopherol correlated with their BAL-cell levels. These studies demonstrate quantifiable levels of retinol, alpha-tocopherol, and total carotenoids or beta-carotene in human lung tissue and BAL cells, and show that serum and/or BAL-cell levels of these nutrients can potentially be used to predict their lung tissue levels.