A 30-year-old man comes to the physician because of a 3-month history of pain in his jaw and left arm. He also has had
Posted: Mon Apr 11, 2022 8:25 am
A 30-year-old man comes to the physician because of a 3-month history of pain in his jaw and left arm. He also has had intense thirst and increased urination during this period. He was found to have peptic ulcer disease 2 months ago. Physical examination shows no abnormalities. Serum studies show a calcium concentration of 13.5 mg/dl and an intact parathyroid hormone concentration of 110 pg/ml (N=10-65). An x-ray ofthe left humerus shows no abnormalities. Which ofthe following biologic mechanisms best explains the impaired calcium homeostasis in this patient?
A. Decreased calcium reabsorption by renal tubules
B .Decreased expression of parathyroid hormone receptors on osteoblasts
C. Decreased hydroxylation of vitamin D by renal tubule epithelial cells
D. Increased calcitonin secretion by thyroid gland
E. Increased motility of monocytes in bone marrow Increased osteoclast maturation and activity
A. Decreased calcium reabsorption by renal tubules
B .Decreased expression of parathyroid hormone receptors on osteoblasts
C. Decreased hydroxylation of vitamin D by renal tubule epithelial cells
D. Increased calcitonin secretion by thyroid gland
E. Increased motility of monocytes in bone marrow Increased osteoclast maturation and activity