Alkaline Phosphatases: Structure, substrate specificity and functional relatedness to other members of a large superfamily of enzymes

Our knowledge of the structure and function of alkaline phosphatases has increased greatly in recent years. The crystal structure of the human placental isozyme has enabled us to probe salient features of the mammalian enzymes that differ from those of the bacterial enzymes. The availability of knockout mice deficient in each of the murine alkaline phosphatase isozymes has also given deep insights into their in vivo role. This has been particularly true for probing the biological role of bone alkaline phosphatase during skeletal mineralization. Due to space constraints this mini-review focuses exclusively on structural and functional features of mammalian alkaline phosphatases as identified by crystallography and probed by site-directed mutagenesis and kinetic analysis. An emphasis is also placed on the substrate specificity of alkaline phosphatases, their catalytic properties as phosphohydrolases as well as phosphodiesterases and their structural and functional relatedness to a large superfamily of enzymes that includes nucleotide pyrophosphatase/phosphodiesterase

Role of Haptoglobin in Polycystic Ovary Syndrome (PCOS), Obesity and Disorders of Glucose Tolerance in Premenopausal Women

alleles of the haptoglobin α–chain polymorphism reduce the anti-oxidant properties and increase the pro-inflammatory actions of this acute-phase protein in a gene-dosage fashion. We hypothesized that the haptoglobin polymorphism might contribute to the increased oxidative stress and low-grade chronic inflammation frequently associated with polycystic ovary syndrome, obesity, and abnormalities of glucose tolerance.<0.001), yet no association was found between obesity and haptoglobin genotypes. No differences were observed in haptoglobin levels or genotype frequencies depending on glucose tolerance. Fifty percent of the variation in serum haptoglobin concentrations was explained by the variability in serum C-reactive protein concentrations, BMI, insulin sensitivity and haptoglobin genotypes. alleles suggests that the anti-oxidant and anti-inflammatory properties of haptoglobin may be reduced in these patients

The Appearance and Modulation of Osteocyte Marker Expression during Calcification of Vascular Smooth Muscle Cells

Vascular calcification is an indicator of elevated cardiovascular risk. Vascular smooth muscle cells (VSMCs), the predominant cell type involved in medial vascular calcification, can undergo phenotypic transition to both osteoblastic and chondrocytic cells within a calcifying environment.In the present study, using in vitro VSMC calcification studies in conjunction with ex vivo analyses of a mouse model of medial calcification, we show that vascular calcification is also associated with the expression of osteocyte phenotype markers. As controls, the terminal differentiation of murine calvarial osteoblasts into osteocytes was induced in vitro in the presence of calcifying medium (containing ß-glycerophosphate and ascorbic acid), as determined by increased expression of the osteocyte markers DMP-1, E11 and sclerostin. Culture of murine aortic VSMCs under identical conditions confirmed that the calcification of these cells can also be induced in similar calcifying medium. Calcified VSMCs had increased alkaline phosphatase activity and PiT-1 expression, which are recognized markers of vascular calcification. Expression of DMP-1, E11 and sclerostin was up-regulated during VSMC calcification in vitro. Increased protein expression of E11, an early osteocyte marker, and sclerostin, expressed by more mature osteocytes was also observed in the calcified media of Enpp1(-/-) mouse aortic tissue.This study has demonstrated the up-regulation of key osteocytic molecules during the vascular calcification process. A fuller understanding of the functional role of osteocyte formation and specifically sclerostin and E11 expression in the vascular calcification process may identify novel potential therapeutic strategies for clinical intervention

Altered Antioxidant-Oxidant Status in the Aqueous Humor and Peripheral Blood of Patients with Retinitis Pigmentosa

Retinitis Pigmentosa is a common form of hereditary retinal degeneration constituting the largest Mendelian genetic cause of blindness in the developed world. It has been widely suggested that oxidative stress possibly contributes to its pathogenesis. We measured the levels of total antioxidant capacity, free nitrotyrosine, thiobarbituric acid reactive substances (TBARS) formation, extracellular superoxide dismutase (SOD3) activity, protein, metabolites of the nitric oxide/cyclic GMP pathway, heme oxygenase-I and inducible nitric oxide synthase expression in aqueous humor or/and peripheral blood from fifty-six patients with retinitis pigmentosa and sixty subjects without systemic or ocular oxidative stress-related disease. Multivariate analysis of covariance revealed that retinitis pigmentosa alters ocular antioxidant defence machinery and the redox status in blood. Patients with retinitis pigmentosa present low total antioxidant capacity including reduced SOD3 activity and protein concentration in aqueous humor. Patients also show reduced SOD3 activity, increased TBARS formation and upregulation of the nitric oxide/cyclic GMP pathway in peripheral blood. Together these findings confirmed the hypothesis that patients with retinitis pigmentosa present reduced ocular antioxidant status. Moreover, these patients show changes in some oxidative-nitrosative markers in the peripheral blood. Further studies are needed to clarify the relationship between these peripheral markers and retinitis pigmentosa

EDUCACIÓN AMBIENTAL Y SOCIEDAD. SABERES LOCALES PARA EL DESARROLLO Y LA SUSTENTABILIDAD

Este texto contribuye al análisis científico de varias áreas del conocimiento como la filosofía social, la patología, la educación para el cuidado del medio ambiente y la sustentabilidad que inciden en diversas unidades de aprendizaje de la Licenciatura en Educación para la Salud y de la Maestría en Sociología de la SaludLas comunidades indígenas de la sierra norte de Oaxaca México, habitan un territorio extenso de biodiversidad. Sin que sea una área protegida y sustentable, la propia naturaleza de la región ofrece a sus visitantes la riqueza de la vegetación caracterizada por sus especies endémicas que componen un paisaje de suma belleza

Conducción eléctrica una experiencia considerando imagen y trabajo colaborativo en la enseñanza

This paper shows an experience with pupils of the Secondary School Juan de la Cierva y Codorniu (Totana, Murcia Region) in Spain. It was used multimedia about electromagnetism and superconductivity. It was used the module "Electric Conduction". Experience assesses teaching-learning process about: a) knowledge of computers, b) the medium, c) knowledge of the unit studied, d) conducts observed. Tools of assessment were adapted to the context of the experience. It is very interesting the multimedia access available in http://online.supercomet.no.Se presenta una experiencia realizada con alumnado del Instituto de Educación Secundaria Juan de la Cierva y Codorníu (Totana, Región de Murcia) en España. Se ha trabajado con multimedia dirigido al estudio del electromagnetismo y la superconductividad. Se ha utilizado el módulo "Conducción eléctrica". La experiencia evalúa el proceso de enseñanza-aprendizaje sobre: a) conocimiento que tenía el alumnado sobre el medio informático, b) el medio empleado, c) conocimientos del tema estudiado, d) conductas observables. Los instrumentos de evaluación fueron adaptados de acuerdo al contexto de la experiencia. Resulta muy interesante indicar que se puede acceder al multimedia en http://online.supercomet.no

Enseñar y aprender filosofía en la educación secundaria

El material que presentamos bajo la denominación de Enseñar y aprender Filosofía en la Educación secundaria intenta. por un lado, ayudar a definir de forma dialógico-pragmática el papel que los profesores/as de Filosofía de Educación Secundaria han de desarrollar en el diseño curricular y proponer los cauces necesarios para su ejecución; por otro, trata de aportar unos objetivos, un material de trabajo y una metodología fundamentados en el intercambio de la teoría y la praxis. que puedan servir de guía al quehacer cotidiano filosófico. Si importante es que los profesores/as estén al día e incorporen al programa de curso los avances y descubrimientos que surgen en el campo de su respectiva disciplina aún lo es más que lo hagan en la didáctica, en las técnicas de trabajo intelectual, programación y evaluación didáctica. Se trata, por tanto, de ofrecer un material que ayude a los profesores/as y a los Departamentos o Seminarios didácticos a reflexionar y confeccionar los puntos básicos de su tarea docente (definición de objetivos. metodología, selección de contenidos. experiencias, recursos didácticos. etc.). Dicho material didáctico, sin embargo, no puede, ni pretende ser definitivo sino tan sólo una recopilación actualizada y actualizable de la cual servirse

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Arquitectur