Hyponatremia is associated with an increased risk of death. The economic costs of hyponatremia are estimated at $2.6 billion in the United States. Signs and symptoms of hyponatremia include nausea and vomiting, headache, short-term memory loss, confusion, lethargy, fatigue, loss of appetite, irritability, muscle weakness, spasms or cramps, seizures, and decreased consciousness or coma. The presence and severity of signs and symptoms are related to the level of salt in the blood, with lower levels of plasma sodium associated with more severe symptoms. However, emerging data suggest that mild hyponatremia (plasma sodium levels at 131–135 mmol/L) is associated with numerous complications
Fetal bovine serum the harvesting of blood from the bovine fetus after the fetus is removed from the slaughtered cow. The blood is collected aseptically into a sterile container or blood bag and then allowed to clot. The normal method of collection is cardiac puncture, wherein a needle is inserted into the heart. This minimizes "the danger of serum contamination with micro-organisms from the fetus itself, and the environment". It is then centrifuged to remove the fibrin clot and the remaining blood cells from the clear yellow (straw) colored serum. The serum is frozen prior to further processing that is necessary to make