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1.
Artículo en Inglés | MEDLINE | ID: mdl-30643444

RESUMEN

BACKGROUND: Concentrated hyaluronic acid (HA) gels with a high degree of cross-linking such as Cohesive Polydensified Matrix® (CPM) HA have been designed for long-term facial volume restoration. OBJECTIVE: To determine the behavior and longevity of CPM HA gel, a case series of subjects underwent magnetic resonance imaging (MRI) or computed tomography (CT) scans several years after their initial treatment. METHODS: Six subjects, three from the initial CPM HA Conformité Européenne registration study and three from private practice who had received prior injection of CPM HA for facial volumizing indications agreed to undergo an MRI or CT scan at intervals ranging from 1 to 4 years after the initial treatment. The amount of HA gel originally injected was compared with the amount estimated from volumetric analysis of the MRI and CT scans. The scans were also examined for the signs of any abscess or granuloma formation and to determine the behavior of the HA gel over time. RESULTS: CT and MRI imaging of the six study subjects indicated CPM HA gel persisted for 2-4 years after only a single treatment. In some patients, product was evident in deeper facial fat compartments than originally injected suggesting some diffusion of product had occurred. There was no MRI or CT evidence of abscess or granuloma formation. CONCLUSION: Our findings indicate that CPM HA volumizing gel has substantial longevity when injected subcutaneously or in deep soft tissues.

2.
J Geophys Res Planets ; 123(2): 612-629, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29938148

RESUMEN

Moon Mineralogy Mapper (M3) spectroscopic data and high-resolution imagery data sets were used to study the mineralogy and geology of the 207 km diameter Humboldt crater. Analyses of M3 data, using a custom-made method for M3 spectra continuum removal and spectral parameters calculation, reveal multiple pure crystalline plagioclase detections within the Humboldt crater central peak complex, hinting at its crustal origin. However, olivine, spinel, and glass are observed in the crater walls and rims, suggesting these minerals derive from shallower levels than the plagioclase of the central peak complex. High-calcium pyroxenes are detected in association with volcanic deposits emplaced on the crater's floor. Geologic mapping was performed, and the age of Humboldt crater's units was estimated from crater counts. Results suggest that volcanic activity within this floor-fractured crater spanned over a billion years. The felsic mineralogy of the central peak complex region, which presumably excavated deeper material, and the shallow mafic minerals (olivine and spinel) detected in Humboldt crater walls and rim are not in accordance with the general view of the structure of the lunar crust. Our observations can be explained by the presence of a mafic pluton emplaced in the anorthositic crust prior to the Humboldt-forming impact event. Alternatively, the excavation of Australe basin ejecta could explain the observed mineralogical detections. This highlights the importance of detailed combined mineralogical and geological remote sensing studies to assess the heterogeneity of the lunar crust.

3.
J Geophys Res Planets ; 123(12): 3220-3237, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31007994

RESUMEN

Moon Mineralogy Mapper spectroscopic data were used to investigate the mineralogy of a selection of impact craters' central peaks or peak rings, in order to characterize the lunar crust-mantle interface, and assess its lateral and vertical heterogeneity. The depth of origin of the craters' central peaks or peak rings was calculated using empirical equations, and compared to Gravity Recovery and Interior Laboratory crustal thickness models to select craters tapping within +10/-20 km of the crust-mantle interface. Our results show that plagioclase is widely detected, including in craters allegedly sampling lower crustal to mantle material, except in central peaks where Low-Calcium Pyroxene was detected. Olivine detections are scarce, and identified in material assumed to be derived from both above and below the crust-mantle interface. Mineralogical detections in central peaks show that there is an evolution of the pyroxene composition with depth, that may correspond to the transition from the crust to the mantle. The correlation between High-Calcium Pyroxene and some pyroxene-dominated mixture spectra with the location of maria and cryptomaria hints at the existence of lateral heterogeneities as deep as the crust-mantle interface.

4.
Philos Trans A Math Phys Eng Sci ; 375(2097)2017 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-28554971

RESUMEN

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'.

5.
Science ; 355(6332): 1392-1395, 2017 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-28325842

RESUMEN

The Rosetta spacecraft spent ~2 years orbiting comet 67P/Churyumov-Gerasimenko, most of it at distances that allowed surface characterization and monitoring at submeter scales. From December 2014 to June 2016, numerous localized changes were observed, which we attribute to cometary-specific weathering, erosion, and transient events driven by exposure to sunlight and other processes. While the localized changes suggest compositional or physical heterogeneity, their scale has not resulted in substantial alterations to the comet's landscape. This suggests that most of the major landforms were created early in the comet's current orbital configuration. They may even date from earlier if the comet had a larger volatile inventory, particularly of CO or CO2 ices, or contained amorphous ice, which could have triggered activity at greater distances from the Sun.

6.
Scand J Med Sci Sports ; 27(12): 1576-1587, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28000342

RESUMEN

In order to identify a more appealing exercise strategy for the elderly, we studied a mouse model to determine whether a less time-consuming training program would improve exercise performance, enzyme activities, mitochondrial respiration, and metabolomic parameters. We compared the effects of short-session (acceleration-based) training with those of long-session endurance training in 23-month-old mice. The short-session training consisted of five acceleration-based treadmill running sessions over 2 weeks (the acceleration group), whereas the endurance training consisted of five-one-hour treadmill sessions per week for 4 weeks (the endurance group). A control group of mice was also studied. In the acceleration group, the post-training maximum running speed and time to exhaustion were significantly improved, relative to pretraining values (+8% for speed, P<.05; +10% for time to exhaustion, P<.01). The post-training maximum running speed was higher in the acceleration group than in the endurance group (by 23%; P<.001) and in the control group (by 15%; P<.05). In skeletal muscle samples, the enzymatic activities of citrate synthase, lactate dehydrogenase, and creatine kinase were significantly higher in the acceleration group than in the endurance group. Furthermore, mitochondrial respiratory activity in the gastrocnemius was higher in the acceleration group than in the control group. A metabolomic urine analysis revealed a higher mean taurine concentration and a lower mean branched amino acid concentration in the acceleration group. In old mice, acceleration-based training appears to be an efficient way of increasing performance by improving both aerobic and anaerobic metabolism, and possibly by enhancing antioxidant defenses and maintaining muscle protein balance.


Asunto(s)
Aceleración , Envejecimiento , Músculo Esquelético/fisiología , Condicionamiento Físico Animal/métodos , Carrera/fisiología , Animales , Prueba de Esfuerzo , Ácido Láctico/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Mitocondrias Musculares/fisiología , Modelos Animales , Consumo de Oxígeno , Resistencia Física/fisiología , Distribución Aleatoria , Factores de Tiempo
7.
Science ; 354(6319): 1566-1570, 2016 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-27856849

RESUMEN

The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties.

8.
J Physiol Pharmacol ; 66(3): 355-66, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26084217

RESUMEN

Extracellular matrix metalloproteinase inducer (EMMPRIN), known for its ability to induce matrix metalloproteinase (MMP) expression, was proposed to play a role in the adverse cardiac extracellular matrix remodeling. After observing an age-associated increase in cardiac EMMPRIN expression in both mice and rats, the role and mechanism of action of EMMPRIN was investigated in the myocardial age-associated changes using 3, 12 and 24 month old EMMPRIN knock-out (KO) vs. wild-type (WT) mice, by cardiac echocardiography, Western blots, immunohistochemistry, ELISA and histology. Adilated cardiomyopathy characterized by a decreased ejection fraction and an enlargement of left ventricular chamber (LV) associated with LV hypertrophy, occurred in KO mice as soon as 12 month old. The increase in interstitial collagen deposition during aging in WT mice could not be detected in KO mice. This may be related to the reduced activation (48% reduction; P < 0.05) and signaling (smad2/3 nuclear translocation) of TGF-ß in the 12 month old KO mice which paralleled with a greater reduction in the TGF-ß known activating enzymes such as MT1-MMP and MMP-1 (33% and 37% reduction respectively, between 3 and 12 month old in KO mice; P < 0.05) as well as uPA. These findings demonstrate that EMMPRIN gene silencing is associated with an aberrant extracellular matrix remodeling, characterized by the absence of a detected age-associated fibrosis and consequently to dilated cardiopathy, indicating that a fine regulation of EMMPRIN is essential for the coordinated ECM remodeling during aging.


Asunto(s)
Envejecimiento/fisiología , Basigina/metabolismo , Matriz Extracelular/metabolismo , Remodelación Ventricular/fisiología , Animales , Basigina/genética , Colágeno/metabolismo , Femenino , Masculino , Metaloproteinasas de la Matriz/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Miocardio/metabolismo , Ratas , Ratas Wistar
9.
Science ; 334(6055): 487-90, 2011 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-22034428

RESUMEN

Images obtained by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras onboard the Rosetta spacecraft reveal that asteroid 21 Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4 ± 0.3 grams per cubic centimeter. The north pole region is covered by a thick layer of regolith, which is seen to flow in major landslides associated with albedo variation. Its geologically complex surface, ancient surface age, and high density suggest that Lutetia is most likely a primordial planetesimal. This contrasts with smaller asteroids visited by previous spacecraft, which are probably shattered bodies, fragments of larger parents, or reaccumulated rubble piles.

10.
Curr Pharm Biotechnol ; 11(8): 911-21, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20874685

RESUMEN

Growing evidence indicates that the Mediterranean diet is beneficial to human health. Many epidemiological and research studies have reported that this diet pattern is able to limit the development and progression of coronary heart disease, one of the leading cause of morbidity and mortality in both developed and developing countries worldwide. There is now a large consensus about recommending Mediterranean diet to reduce atherosclerosis and coronary artery disease and to limit the risk of fatal complications such as sudden cardiac death and heart failure. This review underlines the role of two of the specific components of the Mediterranean diet, namely marine omega-3 fatty acids and wine, and the link between moderate wine consumption and fatty acid profiles.


Asunto(s)
Consumo de Bebidas Alcohólicas , Enfermedad Coronaria/prevención & control , Dieta Mediterránea , Ácidos Grasos Omega-3/administración & dosificación , Peces , Salud , Vino , Animales , Aterosclerosis/prevención & control , Presión Sanguínea/efectos de los fármacos , Cardiotónicos/administración & dosificación , Enfermedad Coronaria/etiología , Enfermedad Coronaria/mortalidad , Femenino , Flavonoides/farmacología , Corazón/fisiología , Humanos , Masculino , Fenoles/farmacología , Polifenoles , Accidente Cerebrovascular/prevención & control
11.
Rev Med Interne ; 31(8): 586-9, 2010 Aug.
Artículo en Francés | MEDLINE | ID: mdl-20537443

RESUMEN

Radiation therapy is commonly used in the treatment of cancer. The normal tissue tolerance can be a limit to deliver enough dose to the tumor to be curative. The synchrotron beam presents some interesting physical properties, which could decrease this limitation. Synchrotron beam is a medium energy X-ray nearly parallel beam with high intensity. Three methods are under preclinical investigations: the microbeam, the minibeam and the stereotactic radiotherapy. The first two use a geometric irradiation effect called spatial fractioning. The last one use highly conformational irradiation geometry combined with a dose enhancement due to the presence of high-Z element in the target. Synchrotron radiotherapy preclinical experiments have shown some curative effect on rodent glioma models. Following these encouraging results a phase I/II clinical trial of iodinated enhanced stereotactic synchrotron radiotherapy is currently being prepared at the European Synchrotron Radiation Facility.


Asunto(s)
Neoplasias Encefálicas/radioterapia , Sincrotrones , Animales , Humanos , Radioterapia/métodos , Técnicas Estereotáxicas
12.
Science ; 327(5962): 190-3, 2010 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-20056887

RESUMEN

The European Space Agency's Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote( )imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.

13.
J Physiol Pharmacol ; 61(6): 651-61, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21224495

RESUMEN

Myocardial capillary density and angiogenesis are impaired during aging but whether growth factor therapy is able to induce functional neovascularization in senescent heart have never been studied. In 3, 24, 28 and 32 mo male Wistar rats, cardiac hemodynamic measurements indicated heart failure at 28 and 32 mo, associated with left ventricular hypertrophy. VEGF/VEGF-R2, Ang-1/Ang-2/Tie-2 and PTN levels, quantitated in left ventricle by western blotting and immunohistochemistry, showed that VEGF and VEGF-R2 levels were specifically decreased during aging. In vitro angiogenesis ± rhVEGF-165 (5 and 50 ng/mL) was measured in aortic segments in 3D-collagen. Aortic sprouting was decreased during aging but restored by VEGF treatment (P<0.001), similarly in 3 and 24 mo with 50 ng/mLVEGF. Finally, 3 and 24 mo rats were submitted to in vivo intramyocardial rhVEGF-165 (10 micrograms) or saline solution injection and angiogenesis was measured by SPECT imaging of the alpha(v)beta(3) integrin-targeted tracer (99m)Tc-RAFT-RGD, capillary fluorescence staining in isolated perfused heart and vWF and alpha smooth muscle actin immunohistochemistry, 7 and 21 days later. VEGF administration increased capillary density in 3 but also in 24 mo rats at days 7 (+26%, P<0.01) and 21 (+41%, P<0.01) and arteriolar density at day 21 (+36%, P<0.01). Activity of (99m)Tc-RAFT-RGD and capillary fluorescence labeling indicated that new formed capillaries were functional. Cardiac aging was associated with strong VEGF/VEGF-R2 pathway downregulation. VEGF-165 protein therapy was able to induce in vitro and in vivo angiogenesis during aging. In 24 mo hearts, in vivo angiogenesis was functional, sustained and comparable to neovascularization observed in 3 mo hearts.


Asunto(s)
Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/metabolismo , Miocardio/metabolismo , Proteínas Recombinantes/farmacología , Factor A de Crecimiento Endotelial Vascular/farmacología , Factores de Edad , Animales , Vasos Coronarios/fisiología , Regulación hacia Abajo , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/patología , Humanos , Hipertrofia Ventricular Izquierda/tratamiento farmacológico , Hipertrofia Ventricular Izquierda/patología , Masculino , Miocardio/patología , Neovascularización Fisiológica/efectos de los fármacos , Ratas , Ratas Wistar , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Factor A de Crecimiento Endotelial Vascular/genética , Receptor 2 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética
14.
Cell Death Differ ; 15(8): 1211-20, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18274553

RESUMEN

Translationally controlled tumor protein (TCTP) is a potential target for cancer therapy. It functions as a growth regulating protein implicated in the TSC1-TSC2 -mTOR pathway or a guanine nucleotide dissociation inhibitor for the elongation factors EF1A and EF1Bbeta. Accumulating evidence indicates that TCTP also functions as an antiapoptotic protein, through a hitherto unknown mechanism. In keeping with this, we show here that loss of tctp expression in mice leads to increased spontaneous apoptosis during embryogenesis and causes lethality between E6.5 and E9.5. To gain further mechanistic insights into this apoptotic function, we solved and refined the crystal structure of human TCTP at 2.0 A resolution. We found a structural similarity between the H2-H3 helices of TCTP and the H5-H6 helices of Bax, which have been previously implicated in regulating the mitochondrial membrane permeability during apoptosis. By site-directed mutagenesis we establish the relevance of the H2-H3 helices in TCTP's antiapoptotic function. Finally, we show that TCTP antagonizes apoptosis by inserting into the mitochondrial membrane and inhibiting Bax dimerization. Together, these data therefore further confirm the antiapoptotic role of TCTP in vivo and provide new mechanistic insights into this key function of TCTP.


Asunto(s)
Apoptosis , Biomarcadores de Tumor/química , Biomarcadores de Tumor/metabolismo , Mitocondrias/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Secuencia de Aminoácidos , Animales , Biomarcadores de Tumor/genética , Línea Celular , Cristalografía por Rayos X , Dimerización , Desarrollo Embrionario , Humanos , Ratones , Ratones Noqueados , Datos de Secuencia Molecular , Mutación , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Proteína Tumoral Controlada Traslacionalmente 1 , Proteína X Asociada a bcl-2/química
16.
J Physiol Pharmacol ; 57(4): 541-52, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17229980

RESUMEN

Cardiovascular ageing is associated with an increase in cardiac susceptibility to ischaemia and reperfusion and production of reactive oxygen species has been suspected to be responsible for this age-associated particular vulnerability. To determine whether administration of antioxidant treatment could afford some protection against ischaemia and reperfusion during aging, isolated perfused hearts from adult and senescent rats were submitted to normoxia (180 min), prolonged low-flow ischaemia (15% of initial coronary flow;180 min) or low-flow ischaemia/reperfusion (45 min/30 min), without or with antioxidant enzymes (superoxide dismutase+catalase; 50IU/ml). Contractile function and coronary perfusion were measured and protein oxidation was quantitated in left ventricle after normoxia, ischaemia and ischaemia/reperfusion. Protein oxidation was higher in senescent than in adult hearts after ischaemia-reperfusion, in contrast to prolonged ischaemia. During prolonged ischaemia, antioxidant treatment prevented coronary vasoconstriction at both ages and delayed contractile dysfunction in senescent hearts but did not limit protein oxidation. During reperfusion, antioxidant treatment prevented coronary vasoconstriction and protein oxidation at both ages and considerably improved recovery of contractile function in senescent hearts. In conclusion, antioxidant treatment fully protects the senescent heart against ischaemia/reperfusion but not against prolonged ischaemia injury, indicating that oxidative stress plays a central role in the age-associated vulnerability to ischaemia-reperfusion.


Asunto(s)
Envejecimiento , Antioxidantes/uso terapéutico , Circulación Coronaria/efectos de los fármacos , Corazón , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Estrés Oxidativo/efectos de los fármacos , Proteínas/metabolismo , Envejecimiento/efectos de los fármacos , Envejecimiento/metabolismo , Envejecimiento/fisiología , Animales , Corazón/efectos de los fármacos , Corazón/fisiología , Masculino , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Perfusión , Ratas , Ratas Wistar
17.
Theor Appl Genet ; 110(6): 1119-26, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15726316

RESUMEN

Apple scab (Venturia inaequalis) is one of the most damaging diseases affecting commercial apple production. Some wild Malus species possess resistance against apple scab. One gene, HcrVf2, from a cluster of three genes derived from the wild apple Malus floribunda clone 821, has recently been shown to confer resistance to apple scab when transferred into a scab-susceptible apple variety. For this proof-of-function experiment, the use of the 35S promoter from Cauliflower mosaic virus was reliable and appropriate. However, in order to reduce the amount of non-plant DNA in genetically modified apple to a minimum, with the aim of increasing genetically modified organism acceptability, these genes would ideally be regulated by their own promoters. In this study, sequences from the promoter region of the three members of the HcrVf gene family were compared. Promoter constructs containing progressive 5' deletions were prepared and used for functional analyses. Qualitative assessment confirmed promoter activity in apple. Quantitative promoter comparison was carried out in tobacco (Nicotiana glutinosa) and led to the identification of several promoter regions with different strengths from a basal level to half the strength of the 35S promoter from Cauliflower mosaic virus.


Asunto(s)
Ascomicetos , Genes de Plantas/genética , Inmunidad Innata/genética , Malus/genética , Enfermedades de las Plantas/microbiología , Regiones Promotoras Genéticas/genética , Secuencia de Bases , Cartilla de ADN , Componentes del Gen , Datos de Secuencia Molecular , Plásmidos/genética , Rhizobium , Análisis de Secuencia de ADN , Homología de Secuencia , Nicotiana/genética
18.
Eur J Pharmacol ; 432(2-3): 167-75, 2001 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-11740953

RESUMEN

This study investigated the effects of bosentan, a dual endothelin ET(A) and ET(B) receptor antagonist, during hypoxia-reoxygenation of senescent aorta and during ischemia-reperfusion of senescent heart. Isolated aortic rings and isolated hearts from adult and senescent rats were submitted, respectively, to hypoxia/reoxygenation (20/30 min) and to low-flow ischemia/reperfusion (45/30 min), without or with bosentan (10(-5) M). In the aorta, bosentan treatment prevented the impairment of relaxation in response to acetylcholine after hypoxia-reoxygenation at both ages. In the heart, coronary flow recovery during reperfusion, which is lower in senescents than in adults (48% vs. 76% of baseline value, respectively; P<0.05) was fully prevented by bosentan. Prevention of endothelial dysfunction during reoxygenation of hypoxic aorta and of coronary vasoconstriction during reperfusion of ischemic heart with a dual endothelin ET(A) and ET(B) receptor antagonist suggests a role of endothelin in the vulnerability of aorta to hypoxia-reoxygenation, and of coronary arteries to ischemia-reperfusion, especially during aging.


Asunto(s)
Aorta Torácica/efectos de los fármacos , Vasos Coronarios/efectos de los fármacos , Hipoxia/fisiopatología , Isquemia Miocárdica/fisiopatología , Sulfonamidas/farmacología , Vasoconstricción/efectos de los fármacos , Acetilcolina/farmacología , Envejecimiento , Animales , Aorta Torácica/fisiología , Bosentán , Circulación Coronaria/efectos de los fármacos , Vasos Coronarios/fisiología , Antagonistas de los Receptores de Endotelina , Técnicas In Vitro , Masculino , Nitroprusiato/farmacología , Oxígeno/farmacología , Fenilefrina/farmacología , Ratas , Ratas Wistar , Daño por Reperfusión/fisiopatología , Factores de Tiempo , Vasoconstrictores/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología
19.
Mech Ageing Dev ; 116(1): 15-32, 2000 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-10936505

RESUMEN

Metabolic disorders due to changes in cytosolic glucose utilisation are suspected to be involved in the increased sensitivity of the aged myocardium to ischemia. This study presents the first direct measurement of glucose utilisation in hearts from senescent rats during low-flow ischemia under different conditions of substrate delivery and glycogen stores. Isolated hearts from young adult (4-months-old) and senescent (24-months-old) rats were subjected to 30 min coronary flow restriction (residual flow rate=2% of control flows). Experiments were performed using glucose-free or glucose-enriched (11 mmol/L) perfusion media. The effects of increased glycogen stores were assessed after 24-h fasting in both age groups. Ischemic contracture was measured via a left-ventricular balloon. Ageing increased ischemic contracture under both conditions of substrate delivery in fed rat hearts. The increase in ischemic tolerance induced by fasting in senescent rat hearts was less than that seen in young rat hearts. Moreover, fasting decreased glucose utilisation in hearts from young rats, an effect which was not found in hearts from old rats. Furthermore, myocardial glycogen utilisation was increased in all groups of aged rats compared with that of young adults, particularly under fasting conditions. It is concluded that fasting is less detrimental to the aged myocardium during low-flow ischemia than to the young myocardium because it does not further reduce exogenous glucose utilisation, and it stimulates glycogen consumption. Moreover, a reduction in exogenous glucose utilisation, which is only partly compensated for by increased glycogenolytic flux could be, at least in part, responsible for the increased ischemic contracture in hearts from old fed rats. Finally, our glucose-free experiments suggest that residual oxidative phosphorylation during low-flow ischemia might be less relevant in hearts from senescent rats than in those from young adults.


Asunto(s)
Envejecimiento/fisiología , Glucosa/administración & dosificación , Isquemia Miocárdica/fisiopatología , Animales , Circulación Coronaria , Metabolismo Energético , Ayuno , Glucosa/metabolismo , Glucógeno/metabolismo , Glucólisis , Técnicas In Vitro , Ácido Láctico/metabolismo , Masculino , Miocardio/metabolismo , Fosforilación Oxidativa , Perfusión , Ratas , Ratas Wistar
20.
J Biol Chem ; 275(31): 23919-26, 2000 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-10787418

RESUMEN

Among various other roles described so far, protein kinase CK2 has been involved in cell cycle, proliferation, and development. Here, we show that in response to specific stresses (heat shock or UV irradiation), a pool of the cellular CK2 content relocalizes in a particular nuclear fraction, increasing the activity of the kinase there. Electron microscopic analysis shows that upon heat shock, CK2alpha and CK2beta subunits are both detected in similar speckle structures occurring in the interchromatin space but are differentially targeted inside the nucleolus. This CK2 relocalization process takes place in a time- and dose-dependent manner and is reversible upon recovery at 37 degrees C. Altogether, this work suggests CK2 be involved in the response to physiological stress in higher eukaryotic cells.


Asunto(s)
Nucléolo Celular/metabolismo , Homeostasis , Proteínas Serina-Treonina Quinasas/metabolismo , Células 3T3 , Animales , Transporte Biológico , Quinasa de la Caseína II , Compartimento Celular , Células HeLa , Calor , Humanos , Ratones , Estrés Oxidativo , Fracciones Subcelulares , Rayos Ultravioleta
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