Effect of Dietary Selenium and Cigarette Smoke on Pulmonary Cell Proliferation in Mice

The objective of this study was to determine if dietary selenium could inhibit pulmonary cell proliferation in control and cigarette smoke-exposed female A/J mice. Selenium in the form of sodium selenite was supplemented to purified diets similar to the AIN-93M diet to yield 0.15, 0.5, or 2.0 mg selenium/kg diet. After 3 weeks, mice in each dietary group were divided into two subgroups; one used as control, whereas the other was exposed to cigarette smoke for five consecutive days. Mice from both groups were euthanized 3 days later. Mice were administered bromodeoxyuridine in the drinking water starting 5 days before the initiation of the smoke exposure and continuing until they were euthanized. After euthanasia, the left lung lobe was processed for histology and cell proliferation analysis. Cigarette smoke increased cell proliferation in the terminal bronchioles and large airways, but not in alveoli. High-selenium diets inhibited cell proliferation in the alveoli, terminal bronchioles and large airways areas in both control and smoke-exposed mice. Increasing the dietary selenium level led to increased selenium levels in the blood and lung, and increased glutathione peroxidase (GPx) activity in the lung. Cytochrome P-450 1A1 protein levels in the lung were increased by cigarette smoke but were not affected by dietary selenium. It is concluded that dietary selenium inhibits pulmonary cell proliferation in both control and cigarette smoke-exposed mice, indicating that selenium is inhibiting cell proliferation independently of smoke exposure, and that this inhibition may be related to selenium concentration and GPx activity in the lung

The effect of dietary glycine on the hepatic tumor promoting activity of polychlorinated biphenyls (PCBs) in rats

The wall inside the arcade of the sahn (courtyard), showing a doorway; Ahmed's mosque (also known as the Blue Mosque) was placed in the heart of the city on a site containing the ruins of the Byzantine Great Palace and facing the Hippodrome to the west. It confronted at a distance of some 200 m to the north the most venerated and important mosque in the capital, the converted church of Hagia Sophia. With its six minarets and its semi-domes cascading on four axes, the mosque represents the ultimate evolution of the imperial Ottoman mosque after two centuries of linear development. The exterior arcading of the mosque and courtyard walls, the massing of semi-domes and the four tall and two shorter minarets provide an indelible architectural impression, which marks growing Ottoman architectural self-confidence vis-à-vis Hagia Sophia and contrasts strikingly with the Byzantine church. Source: Grove Art Online; http://www.groveart.com/ (accessed 1/22/2008