pylmonary

Studies of pylmonary clearance of tantalum dust labeled with 182Ta in dogs have been extended to as far as 816 days postexposure in order to substantiate earlier pulmonary retention data, examine lymphatic uptake, and seek long-term pathological changes. Exposure to 5-mug and 10-mug powders was compared with the results of earlier 1-mug studies. The 2.1-year long-term clearance half-time of 1-mug powder was confirmed, while the 5-mug and 10-mug powders were found to have a mean long-term retention half-time of 333 days...

It has recently become apparent that some victims of sudden infant death syndrome (SIDS) are chronically hypoxemic before death. In this study, the structural alterations in the pulmonary circulation of 15 victims of SIDS were examined using precise quantitative morphometric techniques applied to the injected and inflated lung. Increased muscularity of the pulmonary circulation has been demonstrated, as evidenced by the extension of muscle into arteries not usually muscularized during the first year of life, and by an increased thickness of the medial wall in some patients...