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Biomedical subjects

María Pérez

Publications and source records attributed to María Pérez.

6 recordsLinked to original sources
PubMed2006

Combinatorial biosynthesis of antitumor deoxysugar pathways in Streptomyces griseus: Reconstitution of "unnatural natural gene clusters" for the biosynthesis of four 2,6-D-dideoxyhexoses.

Combinatorial biosynthesis was applied to Streptomyces deoxysugar biosynthesis genes in order to reconstitute "unnatural natural gene clusters" for the biosynthesis of four D-deoxysugars (D-olivose, D-oliose, D-digitoxose, and D-boivinose). Expression of these gene clusters in Streptomyces albus 16F4 was used to prove the functionality of the designed clusters through the generation of glycosylated tetracenomycins. Three glycosylated tetracenomycins were generated and characterized, two of which (D-digitoxosyl-tetracenomycin C and D-boivinosyl-tetracenocmycin C) were novel compounds. The constructed gene clusters may be used to increase the capabilities of microorganisms to synthesize new deoxysugars and therefore to produce new glycosylated bioactive compounds.

Antineoplastic Agents↗
PubMed2005

[Prevalence of neuropathic pain in Spain: clinical, working and health care implications].

A narrative systematic medical literature review on prevalence of neuropathic pain (NP) in Spain from 1990 to 2004 was conducted. The average number of publications was 3 per year. Prevalence data varied depending on studied population, definition of pain/pathology and time of pain evolution. The most commonly studied pathologies included: mononeuropathies and polyneuropathies: 42%, multiple sclerosis: 35% and entrapment neuropathies: 16%. Some episodes of NP were left untreated. One third of patients with back pain receiving analgesic treatment still had high intensity pain. Future studies on the prevalence of NP should use work definitions and criteria reached by consensus. An awareness of the clinical presentation of NP and an appropriate and early treatment could minimize its clinical, working and health care implications. NP is a diverse and highly prevalent condition in Spain. Efforts should be conducted towards the achievement of diagnostic criteria consensus and higher rates of analgesic success.

Humans↗
PubMed2005

[Usefulness of parametric imaging-based quantitative myocardial contrast echocardiography in predicting the functional recovery of akinetic segments following primary angioplasty in acute myocardial infarction patients].

INTRODUCTION AND OBJECTIVES: Myocardial contrast echocardiography (MCE) is useful for predicting the functional recovery of akinetic segments in patients undergoing primary angioplasty after acute myocardial infraction (AMI). Recently, parametric imaging-based quantitative MCE has been developed for measuring perfusion. Our aims were: a) to measure perfusion in akinetic myocardial segments in patients undergoing primary angioplasty using parametric imaging-based quantitative MCE; and b) to assess the usefulness of these measurements in predicting functional recovery of these segments. PATIENTS AND METHOD: The study group comprised 49 consecutive patients undergoing primary angioplasty. Both MCE and standard echocardiography were performed between 2 and 5 days after AMI. Six months later, additional standard echocardiography and coronary angiography were performed. Perfusion was quantified independently off-line from parametric images. RESULTS: The patients' mean age was 62.3+/-14.5 years (39 men; 79.2%). Some 170 akinetic segments were detected. Of these, 105 (62.1%) recovered function. The quantitative MCE parameter that best predicted functional recovery was myocardial blood flow velocity (beta): the area under the receiver operating characteristic (ROC) curve was 0.96 (95% CI, 0.92-0.99). For a cut-off point of 31 dB/s, the sensitivity was 87.62%, the specificity was 95.31%, the positive predictive value was 96.8%, and the negative predictive value was 82.43%. These results were better than those obtained using qualitative methods for assessing myocardial perfusion. CONCLUSIONS: Perfusion measurement by parametric imaging-based quantitative MCE is useful for predicting the functional recovery of akinetic segments in patients undergoing primary angioplasty after AMI. The technique provides superior information to older qualitative methods.

Aged↗
PubMed2004

Inhibition of brush border dipeptidase with cilastatin reduces toxic accumulation of cyclosporin A in kidney proximal tubule epithelial cells.

BACKGROUND: Cilastatin reduces nephrotoxicity associated with cyclosporin A (CyA) in solid organ and bone marrow transplantation. This appears to be unrelated to changes in renal haemodynamics or CyA metabolism. How cilastatin induces this protection is unclear, but it could result from changes on accumulation of CyA proximal cells. METHODS: We investigated the effects of cilastatin on primary cultures of pig kidney proximal tubule epithelial cells (PTECs) treated with CyA and FK506. Cell membrane fluidity and membrane-bound cholesterol-rich raft (MBCR) distribution were evaluated by fluorescence microscopy, and CyA transport by radioimmunoassay. Changes in CyA- and FK506-induced apoptosis were also evaluated by electron and light microscopy, flow cytometry, and detection of cytoplasmic nucleosones by enzyme-linked immuosorbent assay. RESULTS: CyA caused a dose-dependent reduction of cell membrane fluidity, which was prevented by pre-treating PTECs with cilastatin. Cilastatin also inhibited CyA transport across membranes and reduced recovery of CyA in mitochondria and membrane-bound fractions from cilastatin-treated PTECs. This effect was not related to an altered distribution of MBCRs, which are essential for CyA transport. Cilastatin protected against CyA- and FK506-induced apoptosis. CONCLUSIONS: Prevention of CyA-induced reduction of cell membrane fluidity and inhibition of CyA transport are features of cilastatin's direct effects on PTECs. Unaltered distribution of MBCRs in the presence of cilastatin suggests that cilastatin binding to raft-bound dipeptidases, rather than MBCR modifications, causes interference with CyA transport. These results provide additional insight into the mechanisms and scope of cilastatin nephroprotection.

Animals↗
PubMed2003

Construction of integrated case environments.

The main goal of Computer-Aided Software Engineering (CASE) technology is to improve the entire software system development process. The CASE approach is not merely a technology; it involves a fundamental change in the process of software development. The tendency of the CASE approach, technically speaking, is the integration of tools that assist in the application of specific methods. In this sense, the environment architecture, which includes the platform and the system's hardware and software, constitutes the base of the CASE environment. The problem of tools integration has been proposed for two decades. Current integration efforts emphasize the interoperability of tools, especially in distributed environments. In this work we use the Brown approach. The environment resulting from the application of this model is called a federative environment, focusing on the fact that this architecture pays special attention to the connections among the components of the environment. This approach is now being used in component-based design. This paper describes a concrete experience in civil engineering and architecture fields, for the construction of an integrated CASE environment. A generic architectural framework based on an intermediary architectural pattern is applied to achieve the integration of the different tools. This intermediary represents the control perspective of the PAC (Presentation-Abstraction-Control) style, which has been implemented as a Mediator pattern and it has been used in the interactive systems domain. In addition, a process is given to construct the integrated CASE.

Journal Article↗