Peptidyl amidating enzyme

Role in human metabolic processes Overview of significant scientific information Definition of population at risk Dietary sources of vitamin C and limitations to vitamin C Information used to derive dietary requirement of vitamin C Future research References Vitamin C (chemical names: ascorbic acid and ascorbate) is a six-carbon lactone which is synthesised from glucose by many animals. Vitamin C is synthesised in the liver in some mammals and in the kidney in birds and reptiles. The inactive precursor protein is progressively hydrolyzed into smaller fragments (one of which is neurophysin I) via a series of enzymes.The last hydrolysis that releases the active oxytocin nonapeptide is catalyzed by peptidylglycine alpha-amidating monooxygenase (PAM).Regrettably, a universally acceptable definition of morphologic criteria for the diagnosis of AAH has not been achieved.This review of the literature examines the epidemiology, gross appearance, light microscopic findings, morphometry, immunohistochemistry, and molecular features of AAH and suggests a set of histopathologic features that may help the practicing pathologist identify this intriguing lesion.

peptidyl amidating enzyme-12

The endocrine system is composed of a number of tissues that secrete their products, endocrine hormones, into the circulatory system; from there they are disseminated throughout the body, regulating the function of distant tissues and maintaining homeostasis.In addition, systemic feedback mechanisms have evolved to regulate the production of endocrine hormones.Once a hormone is secreted by an endocrine tissue, it generally binds to a specific plasma protein carrier, with the complex being disseminated to distant tissues.These features include the following: irregularly bordered focal proliferations of atypical cells spreading along the preexisting alveolar framework; prominent cuboidal to low columnar alveolar epithelial cells with variable degree of atypia but less than that seen in adenocarcinoma; increased cell size and nuclear-cytoplasmic ratio with hyperchromasia and prominent nucleoli, generally intact intercellular attachment of atypical cells with occasional empty-looking spaces between them without high cellularity and without tufting or papillary structures; and slight thickening of the alveolar walls on which the AAH cells have spread, with some fibrosis but without scar formation or significant chronic inflammation of the surrounding lung tissue.Several lines of evidence indicate that AAH is a lesion closely associated with adenocarcinoma of the lung, suggesting AAH may be involved in the early stage of a complex multistep carcinogenesis of pulmonary adenocarcinoma.