Investigations of the effects of calcitriol on the inverse sigmoidal relationship between parathyroid hormone (PTH) and ionized calcium (iCa) have yielded contradictory conclusions, possibly because of variations in experimental and analytical approaches. To clarify the existing literature, PTH-iCa curves were constructed by inducing hypo- and hypercalcemia through alterations in dialysate calc...

To examine the effects of serum calcium concentrations on PTH biosynthesis, rats were made hyper- (serum total calcium, approximately 3.5 mM) or hypocalcemic (approximately 1.25 mM) and steady-state levels of PTH mRNA in parathyroid cells were measured by the primer extension method using a 32P-labeled synthetic oligomer. PTH mRNA levels increased about twofold in the rats made slightly hypocal...

In this paper we study the impact of Minkowski metric matrix on a projection in the Minkowski Space M along with their basic algebraic and geometric properties.The relation between the m-projections and the Minkowski inverse of a matrix A in the minkowski space M is derived. In the remaining portion commutativity of Minkowski inverse in Minkowski Space M is analyzed in terms of m-projections as...

this paper analyzes a linear system of equations when the righthandside is a fuzzy vector and the coefficient matrix is a crisp m-matrix. thefuzzy linear system (fls) is converted to the equivalent crisp system withcoefficient matrix of dimension 2n × 2n. however, solving this crisp system isdifficult for large n because of dimensionality problems . it is shown that thisdifficulty may be avoide...

We consider the Newton iteration for computing the principal matrix pth root, which is rarely used in the application for the bad convergence and the poor stability. We analyze the convergence conditions. In particular it is proved that the method converges for any matrix A having eigenvalues with modulus less than 1 and with positive real part. Based on these results we provide a general algor...

A brief historical perspective reviews studies that tested the hypotheses that PTH induces an anabolic effect in bone, and that the gain in trabecular bone was not at the expense of cortical bone. As PTH reduces the risk of fracture in humans with osteoporosis, the myths that postulated cortical bone porosity and increased bone turnover might increase fracture risk, are examined in the light of...

OBJECTIVE To ascertain whether the parathyroid hormone (PTH) secretion of continuous ambulatory peritoneal dialysis (CAPD) uremic patients could be suppressed by repeated subcutaneous injections of calcitriol (CLT). DESIGN Nonrandomized prospective study with weekly evaluation. SETTING Hospital CAPD clinic. PATIENTS Seven uremic CAPD patients with signs of severe hyperparathyroidism. IN...