Practical diets containing various selenium levels, with and without selenite supplementation, were fed to hens. Eggs were then collected over a 14-day period to determine how quickly changes in dietary selenium affected egg white and yolk selenium. Changes in egg white selenium content were rapid and essentially completed seven days after changing the selenium content of a practical diet. Changes in egg yolk were not yet completed by 14 days. When selenium from practical feedstuffs was fed, the selenium content of dried egg white was about equal to or greater than the selenium content of dried egg yolk. When selenite was fed, the selenium content of dried yolk was higher. Feeding selenomethionine resulted in more selenium in egg white than in egg yolk. Feeding selenocystine resulted in more selenium in egg yolk than egg white, a pattern similar to that from feeding selenite. The data suggest that selenocystine is not incorporated into protein but is metabolized to an inorganic selenium compound.

No abstract

Radiographic examinations of the paranasal sinuses and chests of 187 patients with C.F. from five months to 27 years of age were reviewed. One hundred eight-five patients consistently had opaque maxillary and ethmoidal sinuses. Forty-five patients had normal chest radiographs. These observations show that the paranasal sinuses are almost always affected in children with C.F. Although opaque paranasal sinuses do not indicate the diagnosis of C.F., clear paranasal sinuses exclude this disease with reasonable certainty.

Experiments were conducted to determine the relative effectiveness of selenium (Se) from sodium selenite, selenomethionine and selenocystine for promoting weight gain and preventing exudative diathesis. The chicks used were hatched from eggs low in Se. They were fed a basal diet made up mostly of corn (low in Se) and torula yeast or the basal diet supplemented with various levels of Se from sodium selenite, selenomethionine, or selenocystine. At 10 mug. of added Se per kg of diet, sodium selenite and selenocystine were about equal in promoting weight gain and preventing exudative diathesis. Selenomethionine was less effective. Tissues from chicks fed the various Se sources providing 60 mug. Se per kg of diet for four weeks were analyzed for Se. The content of tissues from chicks fed sodium selenite or selenocystine was similar. Chicks fed selenomethionine had a higher concentration of Se in the pancreas and breast muscle than chicks fed the other two Se sources, but a lower concentration in the kidney, liver, and heart. The level of Se in the kidney, liver, or heart which a Se source produces seems to be more important for preventing exudative diathesis than that which is found in the pancreas or muscle.