Ralston Purina originated in St. Louis in 1894. Itâs store brand foods business, Ralcorp Holdings, who manufactures food products like Post Cereal and Ry-Krisp Bread, is still headquartered here, as well as the Purina pet food brand. The Drury Hotels were founded in St. Louis. Build-A-Bearâs first store was in the St. Louis Galleria and is headquartered here. Brown Shoe Company, who owns Famous Footwear and whose brands include Naturalizer and Buster Brown to name a few, was created here, with headquarters located in Clayton.
The most common cause of macrocytic anemia is megaloblastic anemia, which is the result of impaired DNA synthesis. Although DNA synthesis is impaired, RNA synthesis is unaffected, leading to a buildup of cytoplasmic components in a slowly dividing cell.This results in a larger-than-normal cell.itamin B-12 deficiency is a cause of macrocytosis. Because DNA synthesis requires cyanocobalamin (vitamin B-12) as a cofactor, a deficiency of the vitamin leads to decreased DNA synthesis in the erythrocyte, thus resulting in macrocytosis.
1 In general, there are three major types of anemia, classified according to the size of the red blood cells:  If the red blood cells are smaller than normal, this is called microcytic anemia. The major causes of this type are iron deficiency (low level iron) anemia and thalassemia (inherited disorders of hemoglobin).