RESUMO
There is a complex interaction between the heart and the lungs. We report on a healthy female who performs breath hold diving at a high, international level. In order to optimize pressure equalization during diving and to increase oxygen available, apneists employed a special breathing maneuver, so called "lung packing". Based on cardiac MRI we could demonstrate impressive effects of this maneuver on left ventricular geometry and hemodynamics. Beyond the fact, that our findings support the concept of pulmonary -cardiac interrelationship, it should be emphasized, that the reported, extreme breathing maneuver could have detrimental consequences due to reduction of stroke volume and cardiac output.
RESUMO
OBJECTIVE: To quantify silicosis and lung cancer risks among porcelain workers occupationally exposed to respirable crystalline silica. METHODS: We reread historical radiographs to identify silicosis and estimated exposure on the basis of detailed work history and about 8000 industrial hygiene measurements. Cox proportional hazards models estimated risks by cumulative and average exposure. RESULTS: Adjusted silicosis hazards ratios were 5.3 (95% confidence interval [CI], 1.6 to 17.3); 7.3 (95% CI, 2.6 to 20.8); and 6.8 (95% CI, 3.0 to 15.3) for cumulative exposures >4 to 5; >5 to 6; and >6 mg/m-years, and 3.3 (95% CI, 0.8 to 14.7), 13.6 (95% CI, 4.2 to 44.4) and 23.2 (95% CI, 8.2 to 65.8) for average exposures >0.1 to 0.15; >0.15 to 0.2 and >0.2 mg/m, respectively. Exposure was not associated with any cause of death including lung cancer. CONCLUSIONS: Respirable crystalline silica exposure more than 4 mg/m-years (cumulative) or more than 0.15 mg/m (average) were strongly associated with silicosis, but unrelated to lung cancer risks.