Bactericidal ZnO glass-filled thermoplastic polyurethane and polydimethyl siloxane composites to inhibit biofilm-associated infections.

This study investigates a novel approach to controlling biofilms of the most frequent pathogens implicated in the etiology of biomaterials-associated infections. New bactericidal filler based on a non-toxic glass, belonging to B2O3-SiO2-Al2O3-Na2O-ZnO system, was used to formulate composites of the most widely used polymers in biomedical applications [i.e. thermoplastic polyurethane (TPU) and polydimethyl siloxane (PDMS)], with varying percentage by weight of the bactericidal glass (5, 15, 25, 35, 50%). Glass-filled polymer composites show dramatically restricted bacterial colonisation and biofilm formation. They exhibit time- and dose-dependent killing, with maximal action at 5 days. The highest activity was found against S.epidermidis biofilm (99% of reduction), one of the most common cause of nosocomial infections. The tensile properties of the obtained glass-filled composites are comparable with the literature data concerning polymeric biomaterials for medical implants and devices. In addition, all the materials presented in this research, revealed an excellent biocompatibility. This was disclosed by cell viability values above 70%, none alteration on erythrocyte membrane or cell functionality in contact with materials (haemolytic index 0-2%), and absence of interferences in blood coagulation (intrinsic, extrinsic and final pathways).

Histological response of soda-lime glass-ceramic bactericidal rods implanted in the jaws of beagle dogs.

Bacterial and fungal infections remain a major clinical challenge. Implant infections very often require complicated revision procedures that are troublesome to patients and costly to the healthcare system. Innovative approaches to tackle infections are urgently needed. We investigated the histological response of novel free P2O5 glass-ceramic rods implanted in the jaws of beagle dogs. Due to the particular percolated morphology of this glass-ceramic, the dissolution of the rods in the animal body environment and the immature bone formation during the fourth months of implantation maintained the integrity of the glass-ceramic rod. No clinical signs of inflammation took place in any of the beagle dogs during the four months of implantation. This new glass-ceramic biomaterial with inherent bactericidal and fungicidal properties can be considered as an appealing candidate for bone tissue engineering.

Biocompatibility assessment of spark plasma-sintered alumina-titanium cermets.

Alumina-titanium materials (cermets) of enhanced mechanical properties have been lately developed. In this work, physical properties such as electrical conductivity and the crystalline phases in the bulk material are evaluated. As these new cermets manufactured by spark plasma sintering may have potential application for hard tissue replacements, their biocompatibility needs to be evaluated. Thus, this research aims to study the cytocompatibility of a novel alumina-titanium (25 vol. % Ti) cermet compared to its pure counterpart, the spark plasma sintered alumina. The influence of the particular surface properties (chemical composition, roughness and wettability) on the pre-osteoblastic cell response is also analyzed. The material electrical resistance revealed that this cermet may be machined to any shape by electroerosion. The investigated specimens had a slightly undulated topography, with a roughness pattern that had similar morphology in all orientations (isotropic roughness) and a sub-micrometric average roughness. Differences in skewness that implied valley-like structures in the cermet and predominance of peaks in alumina were found. The cermet presented a higher surface hydrophilicity than alumina. Any cytotoxicity risk associated with the new materials or with the innovative manufacturing methodology was rejected. Proliferation and early-differentiation stages of osteoblasts were statistically improved on the composite. Thus, our results suggest that this new multifunctional cermet could improve current alumina-based biomedical devices for applications such as hip joint replacements.

Cruising y e-citas: un nuevo contexto para los encuentros sexuales entre hombres jóvenes que tienen sexo con hombres / Cruising e e-compromissos: um novo contexto de encontros sexuais entre os jovens homens que fazem sexo com homens / Cruising and e-dates: a new context for sexual encounters among young men who have sex with men

Resumen El objetivo de este artículo es el de explorar el papel que juega, en la actualidad, la irrupción de la mediación tecnológica de la información y la comunicación en la configuración de nuevos contextos para la relación sexual. En concreto, hemos explorado una práctica determinada, el cruising, entre hombres jóvenes que tienen sexo con hombres contactado a través de las e-citas. Se ha apostado por la metodología cualitativa con la intención de recopilar los discursos sobre sexualidad, riesgos y salud que se generan y construyen entre el grupo de iguales. Según extraemos de nuestro estudio, el nuevo marco que confiere esta tecnología estaría caracterizado por (a) una mayor accesibilidad a dichas prácticas, (b) una mayor difusión de estas, (c) una mayor inmediatez de acceso a las propuestas, (d) la anticipación de lo que será ofrecido en la cita, (e) acceso anónimo que permite propuestas más atrevidas y (f) una apertura mayor a la diversidad de usuarios. Todos estos elementos confluyen en un cuadro que nos lleva a considerar una organización social renovada de la práctica sexual.

Resumo O objetivo deste artigo é explorar o papel que a irrupção da mediação tecnológica da informação e da comunicação desempenha na definição de novos contextos para a relação sexual. Em particular, explora-se uma determinada prática, o cruising entre os homens jovens que fazem sexo com homens contatados via e- encontros. Nossa aposta foi pela metodologia qualitativa, com a intenção de recolher os discursos sobre a sexualidade, a saúde e os riscos que são gerados e construídos entre o grupo de pares. De acordo com o nosso estudo, o novo quadro que oferece essa tecnologia seria marcado por: (a) uma maior acessibilidade a essas práticas; (b) uma maior divulgação das mesmas, bem como (c) um maior imediatismo de acesso para as propostas; (d) a antecipação do que vai ser oferecido no encontro; (e) acesso anônimo que permite propostas mais ousadas; e (f) uma maior abertura para a diversidade de usuários. Todos esses elementos convergem em um contexto que leva-nos a considerar uma nova organização social da prática sexual.

Abstract This article addresses the rapidly growing use of information and communication technologies in mediating new settings for sexual relations. The specific focus is on cruising among young men who have sex with men via e-dating. The study used a qualitative methodology with peer group discussions on sexuality, health, and risk. The new framework provided by technology is marked by (a) increased access to these practices, (b) greater dissemination of them, (c) greater immediacy of encounters, (d) anticipation of what will be offered during dates, (e) anonymous access, allowing bolder proposals, and (f) openness to a wider range of users. These elements converge in a framework that indicates a new social organization of sexual practice.

Peptide-functionalized zirconia and new zirconia/titanium biocermets for dental applications.

OBJECTIVE: Titanium materials have been functionalized with biomolecules as a modern strategy to incorporate bioactive motifs that will expand and improve their biomedical applications. Here, we have biofunctionalized biomaterials based on zirconia of much interest for dentistry: the widely used bioceramic 3Y-TZP and a newly developed 3Y-TZP/Ti biocermet. METHODS: The biosurfaces were activated, silanized, and functionalized with coatings made of oligopeptides. Surface activation by plasma or alkaline-etching was optimized. The surfaces were coated by tethering a purposely-designed RGD-containing peptide. We selected this oligopeptide as a model peptide to validate the effectiveness of the biofunctionalization process. Successful treatments after each step of the process were assessed by surface physical and chemical characterization with water contact angles and XPS, respectively. Coatings' stability was evaluated after 2h sonication in water. Pre-osteoblasts adhesion on the functionalized surfaces was also studied. RESULTS: 10-min air-plasma treatment effectively activated all types of materials with no detrimental effects on the material structure and hardness. Nitrogen XPS-peak confirmed that RGD-peptides were chemically-attached on the silanized samples. This was further confirmed by visualizing the functionalized surfaces with flourescence-labelled RGD-peptides before and after ultrasonication. Furthermore, RGD-functionalized surfaces significantly enhanced osteoblast adhesion on all types of substrates, which demonstrated their successful bioactivation. CONCLUSIONS: We successfully developed stable functional biocoatings on zirconia and biocermets made of oligopeptides. Surface bioactivation of zirconia-containing components for dental implant applications will enable their improved clinical performance by incorporating signalling oligopeptides to accelerate osseointegration, improving permucosal sealing, and/or incorporating antimicrobial properties to prevent peri-implant infections.

Cruising and e-dates: a new context for sexual encounters among young men who have sex with men.

This article addresses the rapidly growing use of information and communication technologies in mediating new settings for sexual relations. The specific focus is on cruising among young men who have sex with men via e-dating. The study used a qualitative methodology with peer group discussions on sexuality, health, and risk. The new framework provided by technology is marked by (a) increased access to these practices, (b) greater dissemination of them, (c) greater immediacy of encounters, (d) anticipation of what will be offered during dates, (e) anonymous access, allowing bolder proposals, and (f) openness to a wider range of users. These elements converge in a framework that indicates a new social organization of sexual practice.

Osteoblastic cell response to spark plasma-sintered zirconia/titanium cermets.

Ceramic/metal composites, cermets, arise from the idea to combine the dissimilar properties in the pure materials. This work aims to study the biocompatibility of new micro-nanostructured 3 Y-TZP/Ti materials with 25, 50 and 75 vol.% Ti, which have been successfully obtained by spark slasma sintering technology, as well as to correlate their surface properties (roughness, wettability and chemical composition) with the osteoblastic cell response. All samples had isotropic and slightly waved microstructure, with sub-micrometric average roughness. Composites with 75 vol.% Ti had the highest surface hydrophilicity. Surface chemical composition of the cermets correlated well with the relative amounts used for their fabrication. A cell viability rate over 80% dismissed any cytotoxicity risk due to manufacturing. Cell adhesion and early differentiation were significantly enhanced on materials containing the nanostructured 3 Y-TZP phase. Proliferation and differentiation of SaOS-2 were significantly improved in their late-stage on the composite with 75 vol.% Ti that, from the osseointegration standpoint, is presented as an excellent biomaterial for bone replacement. Thus, spark plasma sintering is consolidated as a suitable technology for manufacturing nanostructured biomaterials with enhanced bioactivity.

Antiagregación, diabetes y prevención cardiovascular primaria. Revisión crítica de las recomendaciones de la Asociación Americana de Diabetes / Antiplatelet treatment, diabetes mellitus and primary cardiovascular prevention. A critical appraisal of the American Diabetes Association statement

La Asociación Americana de Diabetes recomendó por primera vez en 1997 el uso de aspirina en dosis bajas (75-162 mg/día) para la prevención primaria de episodios cardiovasculares en todo paciente con diabetes, tipo1 o tipo 2, mayor de 40 años, y en todos los menores de 40 y mayores de 30 años que presentasen otro factor de riesgo cardiovascular, además de la diabetes (antecedentes familiares de enfermedad vascular, hipertensión arterial, tabaquismo, dislipidemia o microalbuminuria). La alergia a la aspirina, la predisposición a sufrir hemorragias, la terapia anticoagulante, el sangrado digestivo reciente o la enfermedad hepática activa constituyen contraindicaciones para el empleo de aspirina y se sugiere que otros antiagregantes serían una alternativa aceptable para pacientes en esta situación y con riesgo cardiovascular elevado. La terapia combinada con aspirina y clopidogrel se reserva como estrategia para la prevención secundaria. Estas directrices continúan vigentes en 2008. Muchas otras sociedades científicas y autores a título particular han aceptado la conveniencia de la antiagregación generalizada en los pacientes con diabetes para la prevención cardiovascular primaria, aunque reconocen que las pruebas que existen sobre su beneficio son escasas. Este trabajo es una revisión actualizada de tales pruebas, sobre las que, en definitiva, deberían basarse las recomendaciones.

The American Association of Diabetes recommended forthe first time in 1997 the use of low dose of aspirin (75-162 mg/day) for the primary prevention of cardiovascularevents in every type 1 or type 2 diabetic patient over 40years of age, and in everyone less than 40 and over 30years that may have another factor of cardiovascular risk, besides diabetes (family history of cardiovascular disease, hypertension, smoking, dyslipidemia or albuminuria). Other antiplatelet agents may be a reasonable alternativefor high-risk patients with aspirin allergy, with bleedingtendency, who are receiving anticoagulant therapy, withrecent gastrointestinal bleeding, and with clinically active hepatic disease who are not candidates for aspirintherapy. Combination therapy using other antiplateleta agents such as clopidogrel in addition to aspirin is reservedto secondary prevention strategy. These directivescontinue effective in 2008. Many other scientific societiesand individual authors have accepted the convenienceof the generalized antiaggregation for primarycardiovascular prevention in patients with diabetes, although they recognize that available evidence of benefitis scarce. This work is an updated revision of suchevidence, on which the recommendations would haveto be based.

La prevención primaria con aspirina de enfermedades cardiovasculares en pacientes diabéticos. ¿Qué pruebas sustentan los criterios de la ADA? / Primary prevention with Aspirin for cardiovascular diseases in diabetic patients. What evidence supports the criteria of the ADA?

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[Aspirin for the primary prevention of cardiovascular diseases in diabetic patients. A review of currently available tests]. / La prevención primaria con aspirina de enfermedades cardiovasculares en personas diabéticas. Revisión de las pruebas disponibles.

The benefits of aspirin treatment in reducing the risk of myocardial infarction, cerebrovascular accidents and vascular death is well-documented among individuals having prior cardiovascular disease, including the subgroup with diabetes mellitus. The role of aspirin in primary prevention is less clear and debatable: the results of the clinical trials currently available are not consistent, although the meta-analyses are favorable in some aspects. There seems to be a disparity between the type of benefit (when found to exist) and gender, the findings being particularly contradictory for diabetic subjects, totalling a minor percentage of the population sample included in the studies. Despite this fact, in 1997, the American Diabetes Association and more recently other scientific societies (including several Spanish societies) have been recommending the use of aspirin in low doses in primary prevention in all type 1 or type 2 diabetic patients over 40 years of age and in all those within the 21-40 age range having any other cardiovascular risk factor in addition to diabetes (family history of vascular disease, hypertension, smoking, dyslipidemia or albuminuria). This study reviews the findings of the randomized, controlled clinical trials on primary cardiovascular prevention with aspirin, on which the official American Diabetes Association guidelines might be based, the conclusion being reached that there is not currently sufficient scientific evidence to uphold these guidelines.

La prevención primaria con aspirina de enfermedades cardiovasculares en personas diabéticas. Revisión de las pruebas disponibles / Aspirin for the primary prevention of cardiovascular diseases in diabetic patients. A review of currently available tests

El beneficio del tratamiento con aspirina en la reducción del riesgode infarto de miocardio, accidente vascular cerebral y muerte deorigen vascular, está bien documentado en personas con enfermedadcardiovascular previa, incluido el subgrupo portador de una diabetesmellitus. Sin embargo el papel de la aspirina en prevención primariaes menos claro y objeto de discusión: los resultados de los ensayosclínicos disponibles no son consistentes, aunque los meta-análisisson favorables en algunos aspectos. Parece existir una disparidadentre el tipo de beneficio (cuando se observa) y el sexo. Y en particularlos resultados son contradictorios en personas diabéticas, lascuales representan un pequeño porcentaje de la muestra de poblaciónincluida en los estudios. A pesar de esto, la American Diabetes Associationdesde 1997, y otras sociedades científicas (incluidas variasespañolas) desde tiempos más recientes, recomiendan el uso de aspirinaa dosis bajas en prevención primaria en todo paciente diabéticomayor de 40 años, tipo 1 o tipo 2; y en todos los menores de 40 ymayores de 21 años que presenten otro factor de riesgo cardiovascular,además de la diabetes (antecedentes familiares de enfermedadvascular, hipertensión arterial, tabaquismo, dislipidemia o albuminuria).En este trabajo se revisan los resultados de los ensayos clínicosrandomizados y controlados sobre la prevención cardiovascular primariacon aspirina, en los que se podrían apoyar las directrices oficialesde la American Diabetes Association, y se llega a la conclusiónde que no existen actualmente pruebas científicas suficientes parasostenerlas(AU)

The benefits of aspirin treatment in reducing the risk of myocardialinfarction, cerebrovascular accidents and vascular death iswell-documented among individuals having prior cardiovasculardisease, including the subgroup with diabetes mellitus. The role ofaspirin in primary prevention is less clear and debatable: the resultsof the clinical trials currently available are not consistent, althoughthe meta-analyses are favorable in some aspects. There seems to bea disparity between the type of benefit (when found to exist) andgender, the findings being particularly contradictory for diabeticsubjects, totalling a minor percentage of the population sampleincluded in the studies. Despite this fact, in 1997, the AmericanDiabetes Association and more recently other scientific societies(including several Spanish societies) have been recommending theuse of aspirin in low doses in primary prevention in all type 1 ortype 2 diabetic patients over 40 years of age and in all those withinthe 21-40 age range having any other cardiovascular risk factor inaddition to diabetes (family history of vascular disease, hypertension,smoking, dyslipidemia or albuminuria). This study reviewsthe findings of the randomized, controlled clinical trials on primarycardiovascular prevention with aspirin, on which the official AmericanDiabetes Association guidelines might be based, the conclusionbeing reached that there is not currently sufficient scientificevidence to uphold these guidelines(AU)