The hormone released from the pituitary that causes the thyroid gland to produce T4 hormone. TSH uses the second messenger cyclic AMP to initiate the synthesis of T4.
Trans Rectal Ultrasound (TRUS)
TRUS is an examination where a finger-like probe is placed in the rectum, and ultrasound pictures are made of the prostate. TRUS is an even more fuzzy test than the Prostatic Specific Antigen. It is very helpful in directing biopsies to areas of high suspicion, but TRUS is non-diagnostic . It may give information about prostate size, shape, and significant local spread of prostate cancer, but it cannot make or deny the diagnosis of prostate cancer. TRUS should never be done as an isolated test, but only when a biopsy is to be done.

This definition is in context to Hormone Replacement Therapy. See more contextual defintions for Thyroid-Stimulating Hormone (TSH).