317 research outputs found

    Analysis of Moon impact flashes detected during the 2012 and 2013 Perseids

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    We present the results of our Moon impact flashes detection campaigns performed around the maximum activity period of the Perseid meteor shower in 2012 and 2013. Just one flash produced by a Perseid meteoroid was detected in 2012 because of very unfavourable geometric conditions, but 12 of these were confirmed in 2013. The visual magnitude of the flashes ranged between 6.6 and 9.3. A luminous efficiency of 1.8 ×\times 103^{-3} has been estimated for meteoroids from this stream. According to this value, impactor masses would range between 1.9 and 190 g. In addition, we propose a criterion to establish, from a statistical point of view, the likely origin of impact flashes recorded on the lunar surface.Comment: Accepted for publication in Astronomy and Astrophysics on March 11, 201

    Periodontal Disease and Nuclear and Oxidative DNA Damage

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    Oral health is an important aspect of the overall health status of an individual. DNA damage has been associated with oral health and dental factors due to the increased of oxidative stress (OxS). DNA damage can produce a wide range of effects on human health. These effects could appear immediately, but others do not become evident much later. Chronic diseases have been study to understand their mechanisms, clinical implications, and the development of secondary disease such as cancer. Periodontitis is one of the most common oral diseases. It is an inflammatory chronic infectious disease, which is characterized by the loss of supporting tissues and tooth loss caused by periodontopathogens and long-term release of reactive oxygen species (ROS); thus, oxidative stress is increased during periodontitis. Oxidative stress can produce DNA damage, including the oxidation of nucleosides, which could cause DNA strand break. This oxidative damage leads the formation of micronuclei (MN) a marker of nuclear damage. Also, oxidative stress increased 8-hydroxy-2′-deoxyguanosine levels which are the most common stable product of oxidative DNA damage

    Urinary transferrin pre-emptively identifies the risk of renal damage posed by subclinical tubular alterations

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    Nephrotoxicity is an important limitation to the clinical use of many drugs and contrast media. Drug nephrotoxicity occurs in acute, subacute and chronic manifestations ranging from glomerular, tubular, vascular and immunological phenotypes to acute kidney injury. Pre-emptive risk assessment of drug nephrotoxicity poses an urgent need of precision medicine to optimize pharmacological therapies and interventional procedures involving nephrotoxic products in a preventive and personalized manner. Biomarkers of risk have been identified in animal models, and risk scores have been proposed, whose clinical use is abated by their reduced applicability to specific etiological models or clinical circumstances. However, our present data suggest that the urinary level of transferrin may be indicative of risk of renal damage, where risk is induced by subclinical tubular alterations regardless of etiology. In fact, urinary transferrin pre-emptively correlates with the subsequent renal damage in animal models in which risk has been induced by drugs and toxins affecting the renal tubules (i.e. cisplatin, gentamicin and uranyl nitrate); whereas transferrin shows no relation with the risk posed by a drug affecting renal hemodynamics (i.e. cyclosporine A). Our experiments also show that transferrin increases in the urine in the risk state (i.e. prior to the damage) precisely as a consequence of reduced tubular reabsorption. Finally, urinary transferrin pre-emptively identifies subpopulations of oncological and cardiac patients at risk of nephrotoxicity. In perspective, urinary transferrin might be further explored as a wider biomarker of an important mechanism of predisposition to renal damage induced by insults causing subclinical tubular alterations.Research from the authors’ laboratory supporting part of the information incorporated into this article was funded by grants from Instituto de Salud Carlos III (PI14/01776, DT15S/00166, PI15/01055 and PI17/01979, and Retic RD016/0009/0025, REDINREN), Ministerio de Economía y Competitividad (IPT-2012-0779-010000), Junta de Castilla y León (Consejería de Sanidad, BIO/SA20/14, BIO/SA66/15; and Consejería de Educación, SA359U14), and FEDER funds

    Tree-ring distinctness, dating potential and climatic sensitivity of laurel forest tree species in Tenerife Island

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    Producción CientíficaMacaronesian laurel forests are the only remnants of a subtropical palaeoecosystem dominant during the Tertiary in Europe and northern Africa. These biodiverse ecosystems are restricted to cloudy and temperate insular environments in the North Atlantic Ocean. Due to their reduced distribution area, these forests are particularly vulnerable to anthropogenic disturbances and changes in climatic conditions. The assessment of laurel forest trees’ response to climate variation by dendrochronological methods is limited because it was assumed that the lack of marked seasonality would prevent the formation of distinct annual tree rings. The aims of this study were to identify the presence of annual growth rings and to assess the dendrochronological potential of the most representative tree species from laurel forests in Tenerife, Canary Islands. We sampled increment cores from 498 trees of 12 species in two well-preserved forests in Tenerife Island. We evaluated tree-ring boundary distinctness, dating potential, and sensitivity of tree-ring growth to climate and, particularly, to drought occurrence. Eight species showed clear tree-ring boundaries, but synchronic annual tree rings and robust tree-ring chronologies were only obtained for Laurus novocanariensis, Ilex perado subsp. platyphylla, Persea indica and Picconia excelsa, a third of the studied species. Tree-ring width depended on water balance and drought occurrence, showing sharp reductions in growth in the face of decreased water availability, a response that was consistent among species and sites. Inter-annual tree-ring width variation was directly dependent on rainfall input in the humid period, from previous October to current April. The four negative pointer years 1995, 1999, 2008 and 2012 corresponded to severe drought events in the study area. This study gives the first assessment of dendrochronological potential and tree-ring climate sensitivity of tree species from the Tenerife laurel forest, which opens new research avenues for dendroecological studies in Macaronesian laurel forests.Ministerio de Ciencia, Innovación y Universidades (projects PID2019-109906RA-I00, PID2020-118444GA-100 and PID2019-106908RA-I00/AEI/10.13039/501100011033)Ministerio de Ciencia, Innovación y Universidades (predoctoral contract PRE2018-084106)Ministerio de Economía, Industria y Competitividad (project CGL2017-87309-P and postdoctoral grant IJC2019-040571-I)Junta de Castilla y León (projects VA113G19 and IR2020-1-UVA08)Universidad de Valladolid (predoctoral contract 113-2019PREUVA22)Comunidad de Madrid (project S2018/EMT-4338

    Urinary transferrin pre-emptively identifies the risk of renal damage posed by subclinical tubular alterations

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    Nephrotoxicity is an important limitation to the clinical use of many drugs and contrast media. Drug nephrotoxicity occurs in acute, subacute and chronic manifestations ranging from glomerular, tubular, vascular and immunological phenotypes to acute kidney injury. Pre-emptive risk assessment of drug nephrotoxicity posesman urgent need of precision medicine to optimize pharmacological therapies and interventional procedures involving nephrotoxic products in a preventive and personalized manner. Biomarkers of risk have been identified in animal models, and risk scores have been proposed, whose clinical use is abated by their reduced applicability to specific etiological models or clinical circumstances. However, our present data suggest that the urinary level of transferrin may be indicative of risk of renal damage, where risk is induced by subclinical tubular alterations regardless of etiology. In fact, urinary transferrin pre-emptively correlates with the subsequent renal damage in animal models in which risk has been induced by drugs and toxins affecting the renal tubules (i.e. cisplatin, gentamicin and uranyl nitrate); whereas transferrin shows no relation with the risk posed by a drug affecting renal hemodynamics (i.e. cyclosporine A). Our experiments also show that transferrin increases in the urine in the risk state (i.e. prior to the damage) precisely as a consequence of reduced tubular reabsorption. Finally, urinary transferrin pre-emptively identifies subpopulations of oncological and cardiac patients at risk of nephrotoxicity. In perspective, urinary transferrin might be further explored as a wider biomarker of an important mechanism of predisposition to renal damage induced by insults causing subclinical tubular alterations

    Identification of viral infections in the prostate and evaluation of their association with cancer

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    <p>Abstract</p> <p>Background</p> <p>Several viruses with known oncogenic potential infect prostate tissue, among these are the polyomaviruses BKV, JCV, and SV40; human papillomaviruses (HPVs), and human cytomegalovirus (HCMV) infections. Recently, the Xenotropic Murine Leukemia Virus-related gammaretrovirus (XMRV) was identified in prostate tissue with a high prevalence observed in prostate cancer (PC) patients homozygous for the glutamine variant of the RNASEL protein (462Q/Q). Association studies with the R462Q allele and non-XMRV viruses have not been reported. We assessed associations between prostate cancer, prostate viral infections, and the RNASEL 462Q allele in Mexican cancer patients and controls.</p> <p>Methods</p> <p>130 subjects (55 prostate cancer cases and 75 controls) were enrolled in the study. DNA and RNA isolated from prostate tissues were screened for the presence of viral genomes. Genotyping of the RNASEL R462Q variant was performed by Taqman method.</p> <p>Results</p> <p>R/R, R/Q, and Q/Q frequencies for R462Q were 0.62, 0.38, and 0.0 for PC cases and 0.69, 0.24, and 0.07 for controls, respectively. HPV sequences were detected in 11 (20.0%) cases and 4 (5.3%) controls. XMRV and HCMV infections were detected in one and six control samples, respectively. The risk of PC was significantly increased (Odds Ratio = 3.98; 95% CI: 1.17-13.56, p = 0.027) by infection of the prostatic tissue with HPV. BKV, JCV, and SV40 sequences were not detected in any of the tissue samples examined.</p> <p>Conclusions</p> <p>We report a positive association between PC and HPV infection. The 462Q/Q RNASEL genotype was not represented in our PC cases; thus, its interaction with prostate viral infections and cancer could not be evaluated.</p

    Complement component 3 (C3) expression in the hippocampus after excitotoxic injury: role of C/EBPβ

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    [Background] The CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor implicated in the control of proliferation, differentiation, and inflammatory processes mainly in adipose tissue and liver; although more recent results have revealed an important role for this transcription factor in the brain. Previous studies from our laboratory indicated that CCAAT/enhancer-binding protein β is implicated in inflammatory process and brain injury, since mice lacking this gene were less susceptible to kainic acid-induced injury. More recently, we have shown that the complement component 3 gene (C3) is a downstream target of CCAAT/enhancer-binding protein β and it could be a mediator of the proinflammatory effects of this transcription factor in neural cells.[Methods] Adult male Wistar rats (8–12 weeks old) were used throughout the study. C/EBPβ+/+ and C/EBPβ–/– mice were generated from heterozygous breeding pairs. Animals were injected or not with kainic acid, brains removed, and brain slices containing the hippocampus analyzed for the expression of both CCAAT/enhancer-binding protein β and C3.[Results] In the present work, we have further extended these studies and show that CCAAT/enhancer-binding protein β and C3 co-express in the CA1 and CA3 regions of the hippocampus after an excitotoxic injury. Studies using CCAAT/enhancer-binding protein β knockout mice demonstrate a marked reduction in C3 expression after kainic acid injection in these animals, suggesting that indeed this protein is regulated by C/EBPβ in the hippocampus in vivo.[Conclusions] Altogether these results suggest that CCAAT/enhancer-binding protein β could regulate brain disorders, in which excitotoxic and inflammatory processes are involved, at least in part through the direct regulation of C3.This work was supported by MINECO, Grant SAF2014-52940-R and partially financed with FEDER funds. CIBERNED is funded by the Instituto de Salud Carlos III. JAM-G was supported by CIBERNED. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe
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