Publications by authors named "Isabel Bolivar"

Juxtapapillary retinal capillary hemangiomas are sight-threatening hamartomas located on or adjacent to the optic nerve. Nonsurgical approaches including laser photocoagulation and cryotherapy have been shown to be effective to reduce exudation in peripheral hemangiomas. However, in juxtapapillary hemangiomas, the functional outcomes are limited due to associated potential damage of the retinal nerve fiber layer.

View Article and Find Full Text PDF

Introduction: Mesenchymal tumors comprise only 1 to 2% of all pancreatic tumors, being lipomas a rare variant of mesenchymal tumors of the pancreas.

Presentation Of Case: This is the report of an 82-year-old woman who presented at the medical emergency room in a fourth level clinic with five days of nausea evolution, emesis, jaundice, coluria, acholia, and abdominal pain in the right hypochondrium. Diagnostic imaging and ultrasonography discovered and characterized a significant dilation of the intra and extrahepatic bile duct, caused by the presence of a mass in the head of the pancreas of lipomatous origin.

View Article and Find Full Text PDF

The differential effects between cinacalcet and active vitamin D compounds on parathyroid function, mineral metabolism, and skeletal function are incompletely understood. Here, we studied cinacalcet and active vitamin D compounds in mice expressing the null mutation for Cyp27b1, which encodes 25-hydroxyvitamin D-1α-hydroxylase, thereby lacking endogenous 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)]. Vehicle-treated mice given high dietary calcium had hypocalcemia, hypophosphatemia, and marked secondary hyperparathyroidism.

View Article and Find Full Text PDF

We examined parathyroid and skeletal function in 3-month-old mice expressing the null mutation for 25-hydroxyvitamin D-1alpha-hydroxylase [1alpha(OH)ase(-/-)] and in mice expressing the null mutation for both the 1alpha(OH)ase and the calcium-sensing receptor [Casr(-/-)1alpha(OH)ase(-/-)] genes. On a normal diet, all mice were hypocalcemic, with markedly increased parathyroid hormone (PTH), increased trabecular bone volume, increased osteoblast activity, poorly mineralized bone, enlarged and distorted cartilaginous growth plates, and marked growth retardation, especially in the compound mutants. Osteoclast numbers were reduced in the Casr(-/-)1alpha(OH)ase(-/-) mice.

View Article and Find Full Text PDF

We examined the role of bone remodeling in the regulation of circulating concentrations of FGF23 using mouse models manifesting differing degrees of coupled and uncoupled bone turnover. Administration of the antiresorptive agent osteoprotegerin produced a profound reduction in bone resorption and formation in male and oophorectomized female mice, accompanied by an increase in serum levels of fibroblast growth factor 23 (FGF23) and a reduction in circulating 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. In contrast, exogenous PTH(1-34) administration increased bone turnover and reduced circulating FGF23.

View Article and Find Full Text PDF

Background: Because of the strong association between abdominal obesity (AO) and other cardiovascular risk factors, it has been difficult to determine which changes in vascular function are directly related to this condition. Our objective was to evaluate the changes in ex-vivo vascular reactivity, circulating levels of adipokines and inflammatory markers associated with the presence of AO in subjects who underwent coronary artery bypass graft (CABG) controlling by the presence of other cardiovascular risk factors.

Methods: Subjects scheduled for a CABG with (n=17) and without (n=17) AO (defined as a waist circumference > or =90 cm for male or > or =80 cm for female) whom were matched by several cardiovascular risk factors, were included in the study.

View Article and Find Full Text PDF

We employed a genetic approach to determine whether deficiency of 1,25-dihydroxyvitamin D (1,25(OH)2D) and deficiency of the vitamin D receptor (VDR) produce the same alterations in skeletal and calcium homeostasis and whether calcium can subserve the skeletal functions of 1,25(OH)2D and the VDR. Mice with targeted deletion of the 25-hydroxyvitamin D 1alpha-hydroxylase (1alpha(OH)ase-/-) gene, the VDR gene, and both genes were exposed to 1) a high calcium intake, which maintained fertility but left mice hypocalcemic; 2) this intake plus three times weekly injections of 1,25(OH)2D3, which normalized calcium in the 1alpha(OH)ase-/- mice only; or 3) a "rescue" diet, which normalized calcium in all mutants. These regimens induced different phenotypic changes, thereby disclosing selective modulation by calcium and the vitamin D system.

View Article and Find Full Text PDF

We examined the effect of PTH-related peptide (PTHrP) on modulating adipogenesis and osteoblastogenesis in the pluripotent mesenchymal cell line C3H10T(1/2). These cells express the type 1 PTH/PTHrP receptor, thereby allowing PTHrP to inhibit bone morphogenetic protein 2 (BMP2) from enhancing gene expression of peroxisome proliferator-activated receptor gamma and the adipocyte-specific protein aP2 and from augmenting the accumulation of lipid. In the presence of BMP2, PTHrP or a protein kinase C (PKC) stimulator (phorbol ester) increased the expression of indexes of the osteoblast phenotype, including alkaline phosphatase, type I collagen, and osteocalcin, whereas a PKC inhibitor (chelerythrin chloride) inhibited PTHrP action.

View Article and Find Full Text PDF