Endocrine Abstracts

The cell surface calcium receptor is the primary molecular entity regulating secretion of parathyroid hormone (PTH). Activation of this receptor by extracellular calcium inhibits PTH secretion whereas blocking the calcium receptor stimulates secretion of PTH. Chronically elevated levels of PTH, as occurs in hyperparathyroidism, stimulate bone resorption whereas temporary increases in circulating levels of PTH stimulate bone formation. This stimulatory effect on bone has prompt...

Klinefelter syndrome is an abnormality of sexual development which is usually characterised by the chromosome complement of 47,XXY, although occasionally patients may have multiple X or Y chromosomes, may be mosaic with 46, XY, 47,XXY or have an X-autosome translocation. We present the case of a 43 year old male patient with the phenotypic appearance of Klinefelter syndrome and primary infertility, who was found on karyotype analysis to have an hitherto undescribed inversion o...