Caracterización electroquímica de cuatro biomateriales metálicos de uso odontológico

ABSTRACT: The use of alloys with a minimum of 50% gold-content to minimize the potential of corrosion or galvanism in the implant- restoration interface has been suggested in the literature. However, long – term implications of placing two different kinds of metal at this level is still unknown. The purpose of this study was to perform the electrochemical characterization of four metallic biomaterials used in dentistry, to determine the possibility of corrosion among them when placed in contact during restorative procedures on implant fixtures. A prospective, descriptive, comparative, In - Vitro study was made for this purpose. Four types of metallic biomaterials were compared: commercially pure titanium using as a sample a Super CAT® implant (Lifecore Biomedical Inc., Chaska, MN); highly - noble alloy with a cast made from an UCLA abutment (Lifecore Biomedical Inc., Chaska, MN) with an IPS d.sing® 91 alloy (Williams, Ivoclar Vivadent AG, Liechtenstein); metal-base alloy with a cast made from an UCLA abutment with an IPS d.sing® 15 alloy; titanium alloy (Ti6Al4V) using a Lifecore COC® prosthetic abutment. The electrochemical characterization was made using a Bas Zahner potentiostat, with a three – electrode setup, obtaining three polarization curves for each group in its passive and non passive forms. The results showed that the titanium alloy had the best electrochemical behavior in both passive and non-passive state, which led to the smallest passive currents. The lowest corrosion potential was obtained for the metal-base alloy, because it had the highest passive currents.RESUMEN: En la literatura médica se ha sugerido el uso de aleaciones con un mínimo de 50% de contenido de oro para minimizar la corrosión en la unión implante-restauración. Sin embargo, las implicaciones clínicas a largo plazo de la colocación de dos metales diferentes en restauraciones sobre implantes es aún desconocido. El objetivo de este estudio es realizar la caracterización electroquímica de cuatro biomateriales metálicos de uso odontológico para determinar la posibilidad de corrosión entre ellos cuando se ponen en contacto durante los procedimientos restauradores sobre implantes. Se realizó un estudio in vitro de tipo descriptivo, prospectivo y comparativo. Se trabajó con cuatro tipos de biomateriales metálicos: titanio comercialmente puro, tomando como muestra un implante SuperCAT® de la casa Lifecore (Lifecore Biomedical Inc., Chaska, MN.); metal altamente noble, con un colado que se realizó a partir de un pilar plástico tipo UCLA® (Lifecore Biomedical Inc., Chaska, MN), con aleación IPS d.sign 91® (Williams, Ivoclar Vivadent AG, Liechtenstein); aleación de metal base con un colado que se realizó a partir de un pilar plástico tipo UCLA® con aleación IPS d.sign 15®, y aleación de titanio (Ti6Al 4V), usando un aditamento protésico tipo COC® de la casa comercial Lifecore. Se hizo la caracterización electroquímica de las cuatro aleaciones metálicas mediante un potenciostato Bas Zähner, con una celda de tres electrodos, usando como electrodo de referencia el electrodo de Ag/AgCl, obteniendo tres curvas de polarización para cada grupo en su forma pasivada y sin pasivar. La lectura de las curvas potenciodinámicas realizadas en este estudio, con cuatro biomateriales metálicos, y tomando como criterio el potencial de corrosión, concluye un excelente comportamiento para la aleación de titanio y de metales altamente nobles. La mejor combinación, teniendo en cuenta los criterios de potencial de corrosión y corriente a potenciales anódicos, se da con el titanio comercialmente puro y la aleación de titanio

Calcium phosphate product is associated with subclinical carotid atherosclerosis in type 2 diabetes

Aims. To assess whether circulating 25-hydroxyvitamin D3 (25OHD) and mineral metabolism-related factors (serum phosphate, calcium, and parathormone) are associated with subclinical carotid atherosclerosis (SCA), defined as the presence of carotid atherosclerotic plaques (main study outcome), in patients with type 2 diabetes mellitus (T2DM) without kidney disease or previous cardiovascular disease. Methods. We undertook a post hoc analysis of a cross-sectional study in adults with T2DM in whom we evaluated SCA. A total of 303 subjects with T2DM were included. Clinical variables and carotid ultrasound imaging were obtained. Results. We found no association of 25OHD with the presence of SCA. However, calcium phosphate (CaP; mg2/dL2) product was positively associated with the presence of carotid plaques (ORadj = 1.078; 95% CI: 1.017–1.142). An inverse association was observed between higher levels of 25OHD (≥30 ng/mL versus <20 ng/mL concentrations) and common carotid intima-media thickness (cIMT; mm) (βadj ± SE = −0.055 ± 0.024). We conclude that the CaP product is independently associated with the presence of established subclinical carotid atherosclerosis in patients with T2DM.This study was supported by Grants PS09/01035 and PI15/ 00625 from Instituto de Salud Carlos III, Ministry of Economy and Competitiveness, Spain. CIBERDEM is an initiative from Instituto de Salud Carlos III (Plan Nacional de I+D+I and Fondo Europeo de Desarrollo Regional). Minerva Granado-Casas holds a predoctoral fellowship from Ministerio de Educación, Cultura y Deporte, FPU15/03005

Nomogram-based prediction of survival in patients with advanced oesophagogastric adenocarcinoma receiving first-line chemotherapy: a multicenter prospective study in the era of trastuzumab

Background: To develop and validate a nomogram and web-based calculator to predict overall survival (OS) in Caucasian-advanced oesophagogastric adenocarcinoma (AOA) patients undergoing first-line combination chemotherapy. Methods: Nine hundred twenty-four AOA patients treated at 28 Spanish teaching hospitals from January 2008 to September 2014 were used as derivation cohort. The result of an adjusted-Cox proportional hazards regression was represented as a nomogram and web-based calculator. The model was validated in 502 prospectively recruited patients treated between October 2014 and December 2016. Harrell's c-index was used to evaluate discrimination. Results: The nomogram includes seven predictors associated with OS: HER2-positive tumours treated with trastuzumab, Eastern Cooperative Oncology Group performance status, number of metastatic sites, bone metastases, ascites, histological grade, and neutrophil-to-lymphocyte ratio. Median OS was 5.8 (95% confidence interval (CI), 4.5–6.6), 9.4 (95% CI, 8.5–10.6), and 14 months (95% CI, 11.8–16) for high-, intermediate-, and low-risk groups, respectively (P<0.001), in the derivation set and 4.6 (95% CI, 3.3–8.1), 12.7 (95% CI, 11.3–14.3), and 18.3 months (95% CI, 14.6–24.2) for high-, intermediate-, and low-risk groups, respectively (P<0.001), in the validation set. The nomogram is well-calibrated and reveals acceptable discriminatory capacity, with optimism-corrected c-indices of 0.618 (95% CI, 0.591–0.631) and 0.673 (95% CI, 0.636–0.709) in derivation and validation groups, respectively. The AGAMENON nomogram outperformed the Royal Marsden Hospital (c-index=0.583; P=0.00046) and Japan Clinical Oncology Group prognostic indices (c-index=0.611; P=0.03351). Conclusions: We developed and validated a straightforward model to predict survival in Caucasian AOA patients initiating first-line polychemotherapy. This model can contribute to inform clinical decision-making and optimise clinical trial design

Epidemiología y la relación salud-ambiente : reflexiones sobre el cambio ambiental, desarrollo sustentable y salud poblacional

ABSTRACT: This essay presents a discussion on current environmental problems and their relationship to the health of populations. The limitations of the model of economic and social development are analyzed focusing on the augmentation of the capital and the industrial production and its negative impact on natural resources, the balance of ecosystems and human vulnerability. The methodological basics and the developments in environmental epidemiological approach are exposed analyzing their main potential application. Finally, options for solutions are formulated linking them to the premises of sustainable development and environmental justice. The responsibility of the academic environment is pointed out in the training of human and scientific resources in the field of environmental epidemiology, as well as the role of the community in terms of environmental awareness and active participation from a point of view that becomes critical, responsible and capable of defining proposals to make part of the solution.RESUMEN: Ensayo que presenta una discusión sobre la problemática ambiental actual y su relación con la salud de las poblaciones. Se analizan las limitaciones del modelo de desarrollo económico y social, centrado en el incremento del capital y la producción industrial, y su impacto negativo sobre los recursos naturales, el equilibrio de los ecosistemas y la vulnerabilidad humana. Se exponen los fundamentos metodológicos y los desarrollos del enfoque epidemiológico ambiental, analizando sus principales potenciales de aplicación. Por último, se formulan opciones de solución articuladas a las premisas del desarrollo sustentable y de la justicia ambiental, y se destaca la responsabilidad de la academia en la formación del recurso humano y científico en el área de epidemiología ambiental, así como el papel protagónico de la comunidad en la toma de conciencia ambiental y la participación activa desde una postura crítica, responsable y propositiva para hacer parte de la solución del problema

Assessment of a Genomic Assay in Patients with ERBB2 -Positive Breast Cancer Following Neoadjuvant Trastuzumab-Based Chemotherapy with or Without Pertuzumab

Importance: Biomarkers to guide the use of pertuzumab in the treatment of early-stage ERBB2 (formerly HER2)-positive breast cancer beyond simple ERBB2 status are needed. Objective: To determine if use of the HER2DX genomic assay (Reveal Genomics) in pretreatment baseline tissue samples of patients with ERBB2-positive breast cancer is associated with response to neoadjuvant trastuzumab-based chemotherapy with or without pertuzumab. Design, Setting, and Participants: This is a retrospective diagnostic/prognostic analysis of a multicenter academic observational study in Spain performed during 2018 to 2022 (GOM-HGUGM-2018-05). In addition, a combined analysis with 2 previously reported trials of neoadjuvant cohorts with results from the assay (DAPHNe and I-SPY2) was performed. All patients had stage I to III ERBB2-positive breast cancer, signed informed consent, and had available formalin-fixed paraffin-embedded tumor specimens obtained prior to starting therapy. Exposures: Patients received intravenous trastuzumab, 8 mg/kg, loading dose, followed by 6 mg/kg every 3 weeks in combination with intravenous docetaxel, 75 mg/m2, every 3 weeks and intravenous carboplatin area under the curve of 6 every 3 weeks for 6 cycles, or this regimen plus intravenous pertuzumab, 840 mg, loading dose, followed by an intravenous 420-mg dose every 3 weeks for 6 cycles. Main Outcome and Measures: Association of baseline assay-reported pathologic complete response (pCR) score with pCR in the breast and axilla, as well as association of baseline assay-reported pCR score with response to pertuzumab. Results: The assay was evaluated in 155 patients with ERBB2-positive breast cancer (mean [range] age, 50.3 [26-78] years). Clinical T1 to T2 and node-positive disease was present in 113 (72.9%) and 99 (63.9%) patients, respectively, and 105 (67.7%) tumors were hormone receptor positive. The overall pCR rate was 57.4% (95% CI, 49.2%-65.2%). The proportion of patients in the assay-reported pCR-low, pCR-medium, and pCR-high groups was 53 (34.2%), 54 (34.8%), and 48 (31.0%), respectively. In the multivariable analysis, the assay-reported pCR score (as a continuous variable from 0-100) showed a statistically significant association with pCR (odds ratio [OR] per 10-unit increase, 1.43; 95% CI, 1.22-1.70; P &lt;.001). The pCR rates in the assay-reported pCR-high and pCR-low groups were 75.0% and 28.3%, respectively (OR, 7.85; 95% CI, 2.67-24.91; P &lt;.001). In the combined analysis (n = 282), an increase in pCR rate due to pertuzumab was found in the assay-reported pCR-high tumors (OR, 5.36; 95% CI, 1.89-15.20; P &lt;.001) but not in the assay-reported pCR-low tumors (OR, 0.86; 95% CI, 0.30-2.46; P =.77). A statistically significant interaction between the assay-reported pCR score and the effect of pertuzumab in pCR was observed. Conclusions and Relevance: This diagnostic/prognostic study demonstrated that the genomic assay predicted pCR following neoadjuvant trastuzumab-based chemotherapy with or without pertuzumab. This assay could guide therapeutic decisions regarding the use of neoadjuvant pertuzumab

Coronary pressure and flow relationships in humans: phasic analysis of normal and pathological vessels and the implications for stenosis assessment: a report from the Iberian-Dutch-English (IDEAL) collaborators

Our understanding of human coronary physiological behaviour is derived from animal models. We sought to describe physiological behaviour across a large collection of invasive pressure and flow velocity measurements, to provide a better understanding of the relationships between these physiological parameters and to evaluate the rationale for resting stenosis assessment.Five hundred and sixty-seven simultaneous intracoronary pressure and flow velocity assessments from 301 patients were analysed for coronary flow velocity, trans-stenotic pressure gradient (TG), and microvascular resistance (MVR). Measurements were made during baseline and hyperaemic conditions. The whole cardiac cycle and the diastolic wave-free period were assessed. Stenoses were assessed according to fractional flow reserve (FFR) and quantitative coronary angiography DS%. With progressive worsening of stenoses, from unobstructed angiographic normal vessels to those with FFR ≤ 0.50, hyperaemic flow falls significantly from 45 to 19 cm/s, Ptrend 0.05 for all). Trans-stenotic pressure gradient rose with stenosis severity for both rest and hyperaemic measures (Ptrend < 0.001 for both). Microvascular resistance declines with stenosis severity under resting conditions (Ptrend < 0.001), but was unchanged at hyperaemia (2.3 ± 1.1 mmHg/cm/s; Ptrend = 0.19).With progressive stenosis severity, TG rises. However, while hyperaemic flow falls significantly, resting coronary flow is maintained by compensatory reduction of MVR, demonstrating coronary auto-regulation. These data support the translation of coronary physiological concepts derived from animals to patients with coronary artery disease and furthermore, suggest that resting pressure indices can be used to detect the haemodynamic significance of coronary artery stenoses

Deshidrogenación oxidativa de propano con molibdatos de metales de transición

IP 1115-05-11067El montaje del sistema de reacción con los dispositivos adecuados para lograr medidas confiables de la temperatura y flujos en el rector, además un rector de cuarzo donde se asegura que a temperaturas altas éste no interviene de ninguna manera en la reacción. por otro lado, se obtuvierón tres molibdatos de hierro y tres molibdatos de manganeso nuevos, a dos de ellos se les hizo una caracterización completa, y uno de los molibdatos de hierro se usó como precursor para la obtención de un catalizador