Estudio preliminar sobre algunas rocas volcánicas y volcano-sedimentarias de la provincia de Huelva

Se ha realizado una primera clasificación de algunas rocas volcánicas del Norte de la provincia de Huelva, con base geoquímica. De acuerdo con ésta, se apuntan algunas posibilidades genéticas

Effect of aging in functional redox state of single isolated skeletal muscle fibres

[EN] Skeletal muscle constantly produces reactive oxygen species (ROS). During contractile activity ROS are generated in skeletal muscle fibres. There is considerable support for an involvement of ROS in the process of aging. Several studies indicate that adaptive responses of skeletal muscle that are activated and regulated by ROS are disrupted during aging. The aim of this study was to monitor, in real time, intracellular ROS production in single skeletal muscle fibres from old and young mice and study the effect of contractile activity in these cells. Following evaluate and correlate the potential changes in intracellular ROS production with glutathione redox state and antioxidant enzymatic activities in muscle. Single skeletal muscle fibres were isolated from the Flexor Digitorus Brevis muscle from young (2-4 monthold) and old (26-28 month-old) C57BL/6 mice. Fibres were loaded with DCFH-DA, a fluorophore probe that allows the quantification of intracellular ROS generation by fluorescence microscopy imaging. Contractile activity was induced in fibres by electrical stimulation. Glutathione redox state and activity of antioxidant enzymes were analysed in gastrocnemious muscle. Intracellular basal level of ROS was higher in fibres from old mice. Contractile activity induced increase of ROS generation in fibres from young mice. However, this response was attenuated in fibres from old mice. Glutathione redox state was significant different, in favour of oxidized glutathione, in muscles from old mice. Glutathione peroxidase and catalase activities were significantly augmented in muscles from old mice. In conclusion, the process of aging modifies the basal redox status in skeletal muscle fibres in favour of oxidation and induces adaptation mechanisms of antioxidant defences. These are not able to neutralize the increase of basal oxidation, but they might lead to the attenuation of ROS produced by contractile activity observed in fibres from old mice

Textural and geochemical features of pyrite from the intramagmatic Ni-Cu-PGE mineralization of Aguablanca (Badajoz)

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasFALSEEspaña. Dirección General de Investigación Científica y Técnicapu

Fractionation evidences in the intramagmatic Ni-Cu-PGE mineralization of Aguablanca (Badajoz)

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasFALSEpu

Reactive oxygen species and loss of muscle fibres during ageing

[ES] Sumario de la revista Neuromuscular Disorders: Especies reactivas de oxígeno y pérdida de fibras musculares durante el envejecimiento

Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

[ES] Suplemento de la revista Free Radical Biology and Medicine: Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

All-in-one trifunctional strategy: A cell adhesive, bacteriostatic and bactericidal coating for titanium implants

Strategies to inhibit initial bacterial adhesion are extremely important to prevent infection on biomaterial surfaces. However, the simultaneous attraction of desired eukaryotic cells remains a challenge for successful biomaterial-host tissue integration. Here we describe a method for the development of a trifunctional coating that repels contaminating bacteria, kills those that adhere, and promotes osteoblast adhesion. To this end, titanium surfaces were functionalized by electrodeposition of an antifouling polyethylene glycol (PEG) layer and subsequent binding of a peptidic platform with cell-adhesive and bactericidal properties. The physicochemical characterization of the samples via SEM, contact angle, FTIR and XPS analysis verified the successful binding of the PEG layer and the biomolecules, without altering the morphology and topography of the samples. PEG coatings inhibited protein adsorption and osteoblast-like (SaOS-2) attachment; however, the presence of cell adhesive domains rescued osteoblast adhesion, yielding higher values of cell attachment and spreading compared to controls (p < 0.05). Finally, the antibacterial potential of the coating was measured by live/dead assays and SEM using S. sanguinis as a model of early colonizer in oral biofilms. The presence of PEG layers significantly reduced bacterial attachment on the surfaces (p < 0.05). This antibacterial potential was further increased by the bactericidal peptide, yielding values of bacterial adhesion below 0.2% (p < 0.05). The balance between the risk of infection and the optimal osteointegration of a biomaterial is often described as “the race for the surface”, in which contaminating bacteria and host tissue cells compete to colonize the implant. In the present work, we have developed a multifunctional coating for a titanium surface that promotes the attachment and spreading of osteoblasts, while very efficiently inhibits bacterial colonization, thus holding promise for application in bone replacing applications.Peer ReviewedPostprint (author's final draft

Effect of lifelong overexpression of HSP70 in skeletal muscle on age‐related oxidative stress and adaptation after nondamaging contractile activity

[EN] Skeletal muscle aging is characterized by atrophy, a deficit in specific force generation, increased susceptibility to injury, and incomplete recovery after severe injury. The ability of muscles of old mice to produce heat shock proteins (HSPs) in response to stress is severely diminished. Studies in our laboratory using HSP70 overexpressor mice demonstrated that lifelong overexpression of HSP70 in skeletal muscle provided protection against damage and facilitated successful recovery after damage in muscles of old mice. The mechanisms by which HSP70 provides this protection are unclear. Aging is associated with the accumulation of oxidation products, and it has been proposed that this may play a major role in age-related muscle dysfunction. Muscles of old wild-type (WT) mice demonstrated increased lipid peroxidation, decreased glutathione content, increased catalase and superoxide dismutase (SOD) activities, and an inability to activate nuclear factor (NF)- B after contractions in comparison with adult WT mice. In contrast, levels of lipid peroxidation, glutathione content, and the activities of catalase and SOD in muscles of old HSP70 overexpressor mice were similar to adult mice and these muscles also maintained the ability to activate NF- B after contractions. These data provide an explanation for the preservation of muscle function in old HSP70 overexpressor mice.—Broome, C. S., Kayani, A. C., Palomero, J., Dillmann, W. H., Mestril, R., Jackson, M. J., McArdle, A. Effect of lifelong overexpression of HSP70 in skeletal muscle on age-related oxidative stress and adaptation after nondamaging contractile activity

Effects of S-adenosylmethionine on intrabiliary glutathione degradation induced by long-term administration of cyclosporin A in the rat

[EN] We investigate the ability of S-adenosylmethionine (SAMe) to antagonize the cyclosporine A (CyA)-induced inhibition of biliary glutathione efflux induced by long-term administration of CyA (10 mg/kg per day-CyA10 or 20 mg/kg per day-CyA20 for 4 weeks) in rats. CyA treatment reduced the liver content of total glutathione and caused a significant increase in the oxidized-to-reduced glutathione ratio and the thiobarbituric acid-reactive substances (TBARS) concentration. When the rats were concurrently treated with SAMe (10 mg/kg twice daily) and CyA, all these parameters did not significantly differ from control values. Treatment with CyA induced a significant increase in liver GGT activity that was attenuated by coadministration of SAMe. Biliary efflux of total glutathione was significantly reduced in animals treated with CyA. These changes were abolished by SAMe administration. Following inhibition of the intrabiliary catabolism of the tripeptide by acivicin, glutathione efflux rates increased to a lesser extent in animals cotreated with SAMe when compared to those receiving only CyA. The significant decrease in biliary efflux of oxidized glutathione induced by CyA was totally (S+CyA10) or partially (S+CyA20) prevented by coadministration of SAMe. Our observations confirm that SAMe cotreatment in rats antagonizes CyA-induced inhibition in the biliary efflux of glutathione and suggest that protection against intrabiliary glutathione degradation plays a major role in this protective effect

Effects of aging on the susceptibility to the toxic effects of cyclosporin A in rats. Changes in liver glutathione and antioxidant enzymes

[EN] Free radicals are involved in aging and cyclosporin A-induced toxicity. The age-related changes in the liver oxidative status of glutathione, lipid peroxidation, and the activity of the enzymatic antioxidant defense system, as well as the influence of aging on the susceptibility to the hepatotoxic effects of cyclosporin (CyA) were investigated in rats of different ages (1, 2, 4, and 24 months). The hepatic content of reduced glutathione (GSH) increased with aging, peaked at 4 months, and decreased in senescent rats. By contrast, glutathione disulfide (GSSG) and thiobarbituric acid-reactive substances (TBARS) concentrations and superoxide dismutase, catalase, and glutathione peroxidase activities were higher in the oldest than in the youngest rats. CyA treatment, besides inducing the well-known cholestatic syndrome, increased liver GSSG and TBARS contents and the GSSG/GSH molar ratio, and altered the nonenzymatic and enzymatic antioxidant defense systems. The CyA-induced cholestasis and hepatic depletion of GSH, and the increases in the GSSG/GSH ratio, and in GSSG and TBARS concentrations were higher in the older than the mature rats. Moreover, superoxide dismutase and catalase activities were found to be significantly decreased only in treated senescent rats. The higher CyA-induced oxidative stress, lipoperoxidation, and decreases in the antioxidant defense systems in the aged animals render them more susceptible to the hepatotoxic effects of cyclosporin. © 2001 Elsevier Science Inc