A. Beato-Moreno

Decreased expression of calcium receptor in parathyroid tissue in patients with hyperparathyroidism secondary to chronic renal failure

The response of parathyroid cells to serum calcium is regulated by a calcium-sensing receptor protein (CaR). In patients with chronic renal failure, hypocalcemia contributes to the parathyroid hyperplasia and increased parathyroid hormone secretion characteristic of secondary hyperparathyroidism (sHPT). However, patients with uremia also display reduced sensitivity to extracellular calcium; this seems to be owing to an alteration of the receptor mechanism. This study examined calcium receptor expression in the parathyroid tissue of patients with sHPT, using immunohistochemical technicques and comparison with normal tissue and parathyroid glands of patients with primary hyperparathyroidism. In all the glands studied, immunostaining was more intense in chief cells than in oxyphilic, transitional, and clear cells. The parathyroid glands of patients with sHPT displayed significantly reduced expression of CaR with respect to morphologically normal ones; a very similar reduction is reported in adenomas. Furthermore, in glands displaying multinodular hyperplasia, expression was less marked in nodule-forming cells than in internodular areas. The decreased expression of calcium receptors in the parathyroid tissue of uremic patients was thought to be owing to the different cell populations present; these parathyroid glands contained predominantly transitional, oxyphilic, and clear cells, which normally express fewer receptors than chief cells, which are more abundant in normal glands.

Expression of P-glycoprotein and metallothionein in gastrointestinal stromal tumor and leiomyosarcomas. Clinical implications

We investigated the expression of P-glycoprotein (P-GP) and metallothionein (MT) in a series of 92 GIST and 14 gastrointestinal leiomyosarcomas (GILMS) with the purpose to expand our knowledge on the biological bases of GIST chemo-resistance and to ascertain their significance in patients’ prognosis. P-GP expression was more frequent in GIST than in GI-LMS (83.7% vs. 21.4%, p<0.001), with no difference between low-and high-risk GIST (p=1.000) or low-and high-grade GI-LMS (p=0.538). P-GP expression was unrelated to anatomic location (gastric vs. intestinal) in GIST (39/45 vs. 35/43, p=0.770) and in GI-LMS (0/2 vs. 2/6, p=1.000). MT expression was non-significantly higher in GI-LMS than in GIST (35.7% vs. 14.1%, p=0.060), with no difference between low-and high-risk GIST (p=1.000) or low-and high-grade GI-LMS (p=1.000). MT expression was unrelated to the anatomic location (gastric vs. intestinal) in GIST (7/45 vs. 6/43) and GI-LMS (0/2 vs. 1/6) (p=1.000 and p=0.1000, respectively). Overall tumor-specific survival (p< 0.001) and disease-free survival (p<0.001) were different in GIST as compared with GI-LMS, and the number of events was higher in GI-LMS. When the survival analysis took into consideration P-GP or MT expression, the overall survival in GIST was influenced by the expression of MT (p=0.021) but not by that of P-GP (p=0.638). However, in GI-LMS, P-GP expression influenced disease-free survival (p=0.050); in addition, it is important to recognize the limited value of these results because of the low number of cases involved in the study. Differential expression of P-GP and MT might explain the known variability in response to systemic chemotherapy in these tumors. Detection of P-GP and MT seems to add certain prognostic value in GIST (MT) or GI-LMS (P-GP).

Multiobjective Quadratic Problem: Characterization of the Efficient Points

Here we consider the multiobjective quadratic problem with convex objective functions: (MQP)

Finding Efficient Points in Multiobjective Quadratic Programming with Strictly Convex Objective Functions

\begin{array}{*{20}{c}} {Min\left( {{f_1}\left( x \right), \ldots ,{f_m}\left( x \right)} \right)} \\ {x \in \mathbb{R}} \end{array}

Pareto Optimality Conditions and Duality for Vector Quadratic Fractional Optimization Problems

(1) where ƒ i (x)=1/2 x t A i x+b i t x, i = 1,…,m are convex functions, x,b i ∈ ℝ n , and A i ∈ M n×n

Generalized convexity in multiobjective programming

In this article, we introduce a new condition on functionals of a control problem, and for that purpose we define the KT-invex functionals. We extend recent optimality control works to the study of duality. In this way we establish weak, strong and converse duality results under KT-invexity. Furthermore, we prove that KT-invexity is not only a sufficient condition for establishing duality, but it is necessary.

BCL-2, TP53 and BAX protein expression in superficial urothelial bladder carcinoma

In this work we consider the unconstrained multiobjective quadratic problem with strictly convex objective functions, (PCM — D). Firstly we expose a technique to determine the equations of the efficient points supposing that there are only two objective functions. This method is based on results on quadratic forms withdrawals by Gantmacher. Secondly, the technique explained is extended to calculate the equations of the efficient points of the general problem (PCM — D).

Apoptotic and proliferation indexes in primary superficial bladder tumors

D. H. Martin studied the optimality conditions of in vex functions in the scalar case. In this work we will generalize his results making them applicable to the vectorial case. We will prove that equivalences between minima and stationary points are still true if we have to optimize p-objective functions instead of one objective function.