PART 16: Endocrinology and Metabolism
SECTION 2 Disorders of Bone and Mineral Metabolism
353 Disorders of the Parathyroid Gland and Calcium Homeostasis
 | Figure 353-1 Schematic diagram to illustrate similarities and differences in structure of human parathyroid hormone (PTH) and human PTH-related peptide (PTHrP). Close structural (and functional) homology exists between the first 30 amino acids of hPTH and hPTHrP. The PTHrP sequence may be ≥144 amino acid residues in length. PTH is only 84... |
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 | Figure 353-2 Dual role for the actions of the PTH/PTHrP receptor (PTH1R). Parathyroid hormone (PTH; endocrine-calcium homeostasis) and PTH-related peptide (PTHrP; paracrine–multiple tissue actions including growth plate cartilage in developing bone) use the single receptor for their disparate functions mediated by the amino-terminal 30... |
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 | Figure 353-3 A. Schematic diagram indicating molecular events in tumor susceptibility. The patient with the hereditary abnormality (multiple endocrine neoplasia, or MEN) is envisioned as having one defective gene inherited from the affected parent on chromosome 11, but one... |
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 | Figure 353-4 Levels of immunoreactive parathyroid hormone (PTH) detected in patients with primary hyperparathyroidism, hypercalcemia of malignancy, and hypoparathyroidism. Boxed area represents the upper and normal limits of blood calcium and/or immunoreactive PTH. [From SR Nussbaum, JT Potts, Jr, in L DeGroot, JL... |
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 | Figure 353-5 Illustration of some genetic mutations that alter calcium metabolism by effects on the parathyroid cell or target cells of PTH action. Alterations in PTH production by the parathyroid cell can be caused by changes in the response to extracellular fluid calcium (Ca2+) that are detected by the calcium-sensing receptor... |
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 | Figure 353-6 Algorithm for the evaluation of patients with hypercalcemia. See text for details. FHH, familial hypocalciuric hypercalcemia; MEN, multiple endocrine neoplasia; PTH, parathyroid hormone; PTHrP, parathyroid hormone–related peptide. |
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 | Figure 353-7 Paternal imprinting of renal parathyroid hormone (PTH) resistance (GNAS-1 gene for Gsα subunit) in pseudohypoparathyroidism (PHPIa). An impaired excretion of urinary cyclic AMP and phosphate is observed in patients with PHP. In the renal cortex, there is selective silencing of the... |
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