The cutoff value of serum ferritin for the diagnosis of iron deficiency in community-residing older persons.

The serum ferritin assay is the best single blood test for the diagnosis of iron deficiency. Previous studies with elderly anemic patients have suggested that ferritin level less than 45 mug/L is indicative of iron deficiency. The subjects of these studies were hospitalized patients with anemia, however.

Purification and characterization of a prothrombin-activating protease from Nephila clavata.

We report upon the purification and characterization of a novel prothrombin-activating enzyme from the body fluid (total homogenates of isolated digestive tract without eggs, spinnerets and silk glands) of the spider, Nephila clavata by a combination of acetone fractionation, ion exchange, and Soybean trypsin inhibitor-Sepharose chromatography. Analysis of the purified enzyme with SDS-PAGE and gel filtration revealed a single polypeptide chain with an apparent molecular weight of 24kDa. The proteolytic activity of the enzyme was stable up to 50 degrees C, however, it became unstable over 55 degrees C.