產(chǎn)品名稱：PTH IRMA 產(chǎn) 地：Demeditec 產(chǎn)品貨號：DE3649 產(chǎn)品規(guī)格：96 Tests 產(chǎn)品說明： Special remarks: Biological Activity Human parathyroid hormone (hPTH) is a major physiological regulator of phosphocalcic metabolism. hPTH increases serum calcium concentrations by its actions on kidney (enhancing tubular Ca++ reabsorption and phosphate excretion) and bone (stimulating osteoclastic activity and bone resorption). It indirectly affects intestinal absorption of Ca++ by stimulating renal 1α-hydroxylation of 25 hydroxyvitamin D. The release of PTH is controlled in a negative feedback loop by the serum concentration of Ca++. PTH is synthesized in the chief cells of the parathyroid glands and secreted as an 84 amino acid molecule called "intact PTH", which is the main bioactive product. This molecule is degraded by proteolytic cleavage between amino acids 33-37 at peripheral sites to form biologically active amino-terminal fragments and biologically inactive carboxyl-terminal fragments. The carboxyl-terminal fragments are cleared only by glomerular filtration, while the bioactive intact PTH and amino-terminal fragments are also metabolically degraded in the liver and other tissues. The half-life of the carboxyl-terminal fragments increases dramatically in patients with renal failure. Thus, the measurement of intact PTH correlates best with the hormone production and biological activity. Clinical Application The measurement of intact hPTH by the present IRMA assay kit is used to establish the diagnosis of primary hyperparathyroidism by demonstrating elevated serum levels of bioactive PTH. It allows documenting the occurrence of secondary hyperparathyroidism in patients with Vit.D deficiency, intestinal malabsorption, or renal failure. In this last situation, the absence of interference with the inactive carboxyl-terminal fragments is especially valuable. The specificity and high sensitivity of the assay also allows differentiating clearly low serum PTH levels in hypoparathyroidism or in tumor-induced hypercalcaemia. PRINCIPLES OF THE METHOD The Demeditec hPTH-120 min-IRMA is a two-step immunoradiometric assay based on coated-tube separation. It allows the determination of intact human PTH (hPTH) in serum. Goat antibodies specific to the 1-34 hPTH fragment (N-terminal fragment) are attached to the lower and inner surface of the plastic tubes. Calibrators or samples are added to the tubes. After 1 hour incubation, washing removes the occasional excess of antigen, mid-regional and C-terminal fragments. 125I labelled monoclonal antibodies specific to the 44-68 hPTH fragment are added. After 1 hour incubation and washing the remaining radioactivity bound to the tube reflects the intact h-PTH concentration. This two-step IRMA is highly specific of the intact h-PTH and does not cross react with active and inactive fragments even at high concentrations as suggested by HACKENG et al. 上海玉博生物技術(shù)有限公司在為生命科學(xué)領(lǐng)域提供豐富的產(chǎn)品與信息資源方面處于國內(nèi)**地位，公司提供的產(chǎn)品涵蓋了二十多個國家近五十萬種產(chǎn)品，而且產(chǎn)品的數(shù)量與信息在不斷的增長和更新，公司提供的產(chǎn)品能夠使生命科學(xué)工作者加快對生物化學(xué)，分子生物學(xué)，細(xì)胞生物學(xué)以及蛋白質(zhì)組學(xué)研究的認(rèn)知，以及分子診斷和臨床醫(yī)學(xué)領(lǐng)域的應(yīng)用。
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