Calcium is required for efficient cellular function and signaling, as well as neuromuscular transmission, cardiac contractility, hormone secretion, and blood coagulation. Extracellular calcium concentrations are controlled within an extremely narrow range thanks to a number of feedback processes including parathyroid hormone (PTH) and the active vitamin D metabolite 1,25-dihydroxyvitmin D [1,25(OH)2D]. By activating the calcium…
Sex development starts in utero but progresses with the completion of sexual maturity and reproductive capacity into young adulthood. Three primary components may be classified into the major determinants of sex development: chromosomal sex, gonadal sex (sex determination), and phenotypic type (sex differentiation). Abnormalities at any of these stages can contribute to sex development disorders…
C-Peptide (Connecting peptide) is the binding peptide cleaved in proinsulin insulin processing. Responsive immunoassays in blood and urine can easily detect it. Serum C-peptide is a particularly useful marker of endogenous insulin secretion (a synthetic insulin that does not contain C-peptide). A patient is being diagnosed with exogenous (injected) insulin at the same time, while…
The urinary stones history is as ancient as the civilization itself. Urinary stones are an ancient health problem that have plagued human beings since the dawn of humanity. In 1901, in El Amrah, Egypt, the English archeologist E. Smith discovered a bladder stone from a mummy who was 4,500 to 5,000 years old. Kidney and…
Thyroid tissue is made up of colloid, which includes iodinated thyroglobulin. Thyroglobulin is a big molecule that is synthesized by the surrounding follicular cells and from which thyroxine is produced and processed in colloid. Thyroid neuroendocrine cells (parafollicular or C cells) release calcitonin, a physiologically active peptide, and are situated between the follicular cells. Calcitonin…
