Natasha Romanick is a 19-year old aspiring model who has always dieted to keep h

Question

Natasha Romanick is a 19-year old aspiring model who has always dieted to keep her weight in an "acceptable" range. However, within the past 3 months, she has lost 20 pounds despite a voracious appetite. She complains of nervousness, sleeplessness, heart palpitations, and irregular menstrual periods. She notes that she is "always hot" and wants the thermostat set lower than her apartment mates. On physical examination, Natasha was restless and had a noticeable tremor in her hands. At 5 feet 8 inches tall, she weighed only 110 pounds. Her arterial blood pressure was 160/85, and her heart rate was 110 beats/minute. She was restless, and constantly on the move. Her questions were constant, repetitive, and a little strange. Based on her symptoms, the physician suspected that Natasha had thyrotoxicosis, or hyperthyroidism. However, it was unclear from the available information why her thyroid hormone levels were elevated. Laboratory tests were performed to determine the etiology of her condition. (Table below) Total T4Increased Free T4Increased TSH Undetectable (decreased

Explanation / Answer

1. Resin binding assay uses 2 components a) Resin (having low affinity fot T3) and b) Radiolabelled T3 (Iodine 123-T3).

Both these components are mixed in serum and after some time it is centrifuged to obtain Thyroid binding globulin (TBG) and Resin. Then ratio of bound Resin-I125 T3 and free I125-T3 are measured.

2. Low TSH indicate that there is elevated T3 and T4 (which cause negative feedback inhibition of TSH). TThyroglobulin is required for synthesis of thyroid hormones. It low level indicate that there is over utilization of Thyroglobulin or Antibody to Thyroglobulin that destroy it. (It is a typical case of Hyperthyroidism or Grave's Disease in there is formation of Antibody against TSH receptor and Thyroglobulin).

If you found this answer useful then please rate it.

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.