Biomedical subjects

María Vázquez

Publications and source records attributed to María Vázquez.

4 recordsLinked to original sources

PubMed2005

Ubiquitous expression of human SCA2 gene under the regulation of the SCA2 self promoter cause specific Purkinje cell degeneration in transgenic mice.

The objective of this work was the generation of an animal model of the SCA2 disease for future studies on the benefits of therapeutic molecules and neuropathological mechanisms that underline this human disorder. The transgenic fragment was microinjected into pronuclei of B6D2F1 X OF1 mouse hybrid strain. For Northern blots, RNAs were hybridized with a human cDNA fragment from the SCA2 gene and a mouse beta-actin cDNA fragment. Monoclonal antibody directed to the N-terminal of the ataxin 2 protein with 22Q was used for Western blot analysis. A rotating rod apparatus was utilized to measure motor coordination of mice. Immunohistochemical detection of Purkinje neurons was performed with anti-calbindin 28K as primary antibody. Ubiquitous expression of the SCA2 transgene with 75 CAG repeats regulated by the SCA2 self promoter was obtained after generation of our transgenic mice. Analysis of transgenic mice revealed significant differences of motor coordination compared with the wild type littermates. Specific degeneration of Purkinje neurons and transgene over-expression in the brain, liver and skeletal muscle, rather than in lungs and kidneys was also observed, resembling the expression pattern of the ataxin 2 in humans.

Analysis of Variance↗

PubMed2005

Cells in fluidic environments are sensitive to flow frequency.

Virtually all cells accommodate to their mechanical environment. In particular, cells subject to flow respond to rapid changes in fluid shear stress (SS), cyclic stretch (CS), and pressure. Recent studies have focused on the effect of pulsatility on cellular behavior. Since cells of many different tissue beds are constantly exposed to fluid flows over a narrow range of frequencies, we hypothesized that an intrinsic flow frequency that is optimal for determining cell phenotype exists. We report here that cells from various tissue beds (bovine aortic endothelial cells (BAEC), rat small intestine epithelial cells (RSIEC), and rat lung epithelial cells (RLEC)) proliferate maximally when cultured in a perfusion bioreactor under pulsatile conditions at a specific frequency, independent of the applied SS. Vascular endothelial and pulmonary epithelial cell proliferation peaked under 1 Hz pulsatile flow. In contrast, proliferation of gastrointestinal cells, which in their physiological context are subject to no flow or higher wavelength signal, was maximum at 0.125 Hz or under no flow. Moreover, exposure of BAEC to pulsatile flow of varying frequency influenced their nitric oxide synthase activity and prostacyclin production, which reached maximum values at 1 Hz. Notably, the "optimal" frequencies for the cell types examined correspond to the physiologic operating range of the organs from where they were initially derived. These findings suggest that frequency, independent of shear, is an essential determinant of cell response in pulsatile environments.

Animals↗

PubMed2005

Macrophagic myofasciitis in childhood: a controversial entity.

Macrophagic myofasciitis is an unusual inflammatory myopathy, which has been almost exclusively reported in French adults with diffuse arthromyalgias and asthenia. It is characterized by an infiltrate of densely packed macrophages, with granular periodic-acid-Schiff positive content, on muscle biopsies at the site of vaccination. The presence of aluminum inclusions in these macrophages points to an inappropriate reaction to aluminum used as an adjuvant in some vaccines. Although in adults this entity is well defined, less than 15 cases have been reported in children. This study describes seven children, younger than 3 years of age, with typical lesions of macrophagic myofasciitis on quadriceps muscle biopsy. In five cases, biopsies were performed to exclude mitochondrial pathology. All the children developed hypotonia and motor or psychomotor delay, associated with others symptoms. Abnormal neuroimaging was evident in six cases. Spectrometry studies detected elevated levels of aluminum in muscle in three of four cases tested. Despite the wide use of vaccines in childhood, macrophagic myofasciitis was rarely observed in children and its characteristic histologic pattern could not be correlated with a distinctive clinical syndrome.

Aluminum↗

PubMed2004

Improving access to liver transplantation: the University of Puerto Rico experience.

Liver transplantation is the only treatment for end-stage liver disease. It is costly, difficult, and not performed in Puerto Rico. For these reasons, it has been a limited option for Puerto Ricans with advanced cirrhosis, especially for those with no medical insurance to cover for the procedure. In an effort to improve access to the procedure and offer this chance of life to more Puerto Ricans facing death from complications of advanced liver disease, the Gastroenterology and Liver Diseases Division of the University of Puerto Rico, in collaboration with LifeLink Transplant Institute in Tampa, Florida and the Office of Catastrophic Funds of the Commonwealth of Puerto Rico, opened a clinic for liver transplant evaluation at the Medical Sciences Campus. The purpose of this clinic is to coordinate the pre-transplant evaluation of candidates for this therapy, provide the evaluation by the transplant surgeon in Puerto Rico, expedite the process in seriously ill patients, and offer post-transplant follow-up upon the patient's return to Puerto Rico. The purpose of this article is to describe the experience in this clinic from 1999 to 2003. One hundred ninety-three patients were seen from September 1999 to January 2003. The most common causes for liver disease were hepatitis C and alcohol, alone or in combination. One hundred thirty four were accepted as candidates for evaluation. Of these, 63 had completed the process, 33 were listed for transplantation and 21 had been transplanted by January 2003. Neither education level, marital status, health insurance nor Child score were associated with successful outcome. This clinic offers Puerto Ricans, especially those with limited resources, with a viable access to liver transplantation.

Academic Medical Centers↗