La fractura de tobillo en el adulto: resultados clínico-radiológicos

En el presente trabajo se presenta una revisión retrospectiva de 207 fracturas de tobillo en el adulto tratadas quirúrgicamente en el hospital de Cabueñes de Gijón, entre los años 1986 y 1993. Fueron clasificadas siguiendo los criterios AO, con un seguimiento medio de 10 meses. La valoración de los resultados se realizó utilizando criterios clínico-funcionales y radiológicos, registrándose un 79% de excelentes y buenos resultados clínicos, y un 7% de reducciones no satisfactorias, presentando estas reducciones no satisfactorias una significación estadística (p< 0,01) en las fracturas Tipo C respecto a los otros dos tipos (A y B), y encontrándose variaciones estadísticas respecto al momento en que se realiza la cirugía, con una mayor proporción de resultados excelentes en aquellas fracturas tratadas de precozmente frente a las que lo fueron de forma diferida (p< 0,001).The present work shows a retrospective review of 207 adult ankle fractures operated on the Cabueñes's Hospital of Gijon from 1986 to 1993 with an average of follow-up of 19 months. They were classified according to AO criteria. The assessment of results was based on clinical functional and radiological criteria, recording 79% of excelent and good clinical results, and 7% of no satisfactory reductions. Cases with no satisfactory reductions showed statistical significance (p< 0.01) in the type C respect to the other two types (A y B). Then were also statistical differences with respect to the delay of surgery, with a higher rate of excelent results in the fractures treated early than the fractures treated with delay (p< 0.001

Valor del seguimiento densitométrico en la evaluación de una prótesis total de cadera

En este estudio se ha revisado la evolución clínica, radiográfica y densitométrica de 30 Prótesis Totales de Cadera modelo Bihapro, con recubrimiento de Hidroxiapatita. Se han presentado complicaciones clínicas en 3 casos (10%). La evolución ha sido de incremento de la densidad alrededor de la prótesis en el 97% de los casos. El aumento medio de densidad fue de 1 a 1,3 (cociente hueso periprotésico/hueso normal) en el cotilo y de 1,4 a 1,5 en la zona metafisaria (áreas 1 y 7 de Gruen) del fémur. Los resultados clínicos, radiográficos y densitométricos (Sistema CADIA) han sido coincidentes en el 97% de los casos.In this study we have reviewed the clinical, radiographical and densitometric follow-up of 30 Bihapro® total hip hydroxyapatite-coated arthroplasties. There were complications in 3 cases (10%). Densitometric results showed an increase of bone density around the prosthesis in 97% of cases. The average increase in bone denstiy (periprosthetic/normal bone ratio) varied from 1 to 1.3 in the acetabulum and from 1.4 to 1.5 in the metaphysial area of the femur (Gruen's zones 1 and 7). Clinical, radiographical and densitometric results (CADIA System) exhibited a foot correlation in 97% of cases

Verification tests of a novel ferroresonance detection technique

Abstract. Ferroresonance is a complex electromagnetic phenomenon that affects voltage transformers. The appearance of the ferroresonant phenomenon provokes important oscillations that are responsible for serious thermal and dielectric overstresses, which may lead to catastrophic failures in the electrical power system. This paper analyzes the behaviour of a novel ferroresonance detection technique, based on artificial neural networks, through the results obtained in several verification tests conducted in a real voltage transformer

Corrosion Behavior of Pure Cr, Ni, and Fe Exposed to Molten Salts at High Temperature

Corrosion resistance of pure Fe, Cr, and Ni materials exposed in NaVO3 molten salt at 700°C was evaluated in static air during 100 hours. The corrosion resistance was determined using potentiodynamic polarization, open circuit potential, and lineal polarization resistance. The conventional weight loss method (WLM) was also used during 100 hours. The electrochemical results showed that Fe and Cr have a poor corrosion resistance, whereas pure Ni showed the best corrosion performance, which was supported by the passive layer of NiO formed on the metallic surface and the formation of Ni3V2O8 during the corrosion processes, which is a refractory compound with a higher melting point than that of NaVO3, which reduces the corrosivity of the molten salt. Also, the behavior of these materials was associated with the way in which their corresponding oxides were dissolved together with their type of corrosion attack. Through this study, it was confirmed that when materials suffer corrosion by a localized processes such as pitting, the WLM is not reliable, since a certain amount of corrosion products can be kept inside the pits. The corroded samples were analyzed through scanning electron microscopy

The Rho GDI Rdi1 regulates Rho GTPases by distinct mechanisms

© 2008 by The American Society for Cell Biology. Under the License and Publishing Agreement, authors grant to the general public, effective two months after publication of (i.e.,. the appearance of) the edited manuscript in an online issue of MBoC, the nonexclusive right to copy, distribute, or display the manuscript subject to the terms of the Creative Commons–Noncommercial–Share Alike 3.0 Unported license (http://creativecommons.org/licenses/by-nc-sa/3.0).The small guanosine triphosphate (GTP)-binding proteins of the Rho family are implicated in various cell functions, including establishment and maintenance of cell polarity. Activity of Rho guanosine triphosphatases (GTPases) is not only regulated by guanine nucleotide exchange factors and GTPase-activating proteins but also by guanine nucleotide dissociation inhibitors (GDIs). These proteins have the ability to extract Rho proteins from membranes and keep them in an inactive cytosolic complex. Here, we show that Rdi1, the sole Rho GDI of the yeast Saccharomyces cerevisiae, contributes to pseudohyphal growth and mitotic exit. Rdi1 interacts only with Cdc42, Rho1, and Rho4, and it regulates these Rho GTPases by distinct mechanisms. Binding between Rdi1 and Cdc42 as well as Rho1 is modulated by the Cdc42 effector and p21-activated kinase Cla4. After membrane extraction mediated by Rdi1, Rho4 is degraded by a novel mechanism, which includes the glycogen synthase kinase 3β homologue Ygk3, vacuolar proteases, and the proteasome. Together, these results indicate that Rdi1 uses distinct modes of regulation for different Rho GTPases.Deutsche Forschungsgemeinschaf

Sodium Selenide Toxicity Is Mediated by O2-Dependent DNA Breaks

Hydrogen selenide is a recurrent metabolite of selenium compounds. However, few experiments studied the direct link between this toxic agent and cell death. To address this question, we first screened a systematic collection of Saccharomyces cerevisiae haploid knockout strains for sensitivity to sodium selenide, a donor for hydrogen selenide (H2Se/HSe−/Se2−). Among the genes whose deletion caused hypresensitivity, homologous recombination and DNA damage checkpoint genes were over-represented, suggesting that DNA double-strand breaks are a dominant cause of hydrogen selenide toxicity. Consistent with this hypothesis, treatment of S. cerevisiae cells with sodium selenide triggered G2/M checkpoint activation and induced in vivo chromosome fragmentation. In vitro, sodium selenide directly induced DNA phosphodiester-bond breaks via an O2-dependent reaction. The reaction was inhibited by mannitol, a hydroxyl radical quencher, but not by superoxide dismutase or catalase, strongly suggesting the involvement of hydroxyl radicals and ruling out participations of superoxide anions or hydrogen peroxide. The •OH signature could indeed be detected by electron spin resonance upon exposure of a solution of sodium selenide to O2. Finally we showed that, in vivo, toxicity strictly depended on the presence of O2. Therefore, by combining genome-wide and biochemical approaches, we demonstrated that, in yeast cells, hydrogen selenide induces toxic DNA breaks through an O2-dependent radical-based mechanism