Serum calcitonin is normally produced by the C cells of the thyroid. It functions to reduce serum calcium by inhibiting release of calcium from bone. It is a peptide with a molecular weight of 3400, and has a half life of approximately 12 minutes. It is characteristically elevated in medullary carcinoma of the thyroid. Since medullary carcinoma often occurs as an autosomal disorder, family members of patients with this condition should be screened for serum calcitonin.
Serum calcitonin is typically elevated in which of the following conditions:

A dilution commonly used for a routine sperm count is a 1:20.
A dilution commonly used for a routine sperm count is:

As magnification INCREASES, the field of view will...

Animals serve as a reservoir of infection" is the correct answer because Shigella only infects humans while Salmonella is found in many animals. Both have diarrhea as the major symptom. Endotoxin is produced by all gram negative bacteria and exotoxin is only produced by Shigella.
A major difference between Salmonella enterica and Shigella infections is that only in salmonellosis can:

Set of comprehensive safety guidelines designed to protect patients and health care workers