ABSTRACT
Four bioactive PEO (plasma electrolytic oxidation) coatings were generated on Mg0.8Ca alloy using a Ca/P-based electrolyte and adding Si or Fas necessary. Surface characteristics, chemical composition and ion liberation of the coatings were characterized using SEM/EDS (Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy), X-ray diffraction, optical profilometry and ICP-OES (inductively coupled plasma optical emission spectrometry). Direct biocompatibility studies were performed by seeding premyoblastic, endothelial and preosteoblastic cell lines over the coatings. Biocompatibility of the coatings was also evaluated with respect to murine endothelial, preosteoblastic, preosteoclastic and premyoblastic cell cultures using extracts obtained by the immersion degradation of the PEO-coated specimens. The coatings reduced the degradation of magnesium alloy and released Mg Ca, P, Si and F. Of all the studied compositions, the Si-containing PEO coating exhibited the optimal characteristics for use in all potential applications, including bone regeneration and cardiovascular applications. Coatings with high F content negatively influenced the endothelial cells. RAW 264.7, MC3T3 and co-culture differentiation studies using extracts of PEO coated Mg0.8Ca demonstrated improved osteoclastogenesis and osteoblastogenesis processes compared to bare alloy.
Subject(s)
Alloys/pharmacology , Bone Regeneration/drug effects , Cardiovascular System/drug effects , Coated Materials, Biocompatible/pharmacology , Electrolysis/methods , Plasma Gases/chemistry , Stents , Animals , Calcification, Physiologic/drug effects , Cell Line , Electric Conductivity , Green Fluorescent Proteins/metabolism , Hydrogen-Ion Concentration , Ions , Mice , Osteoblasts/cytology , Osteoclasts/cytology , Oxidation-Reduction , Tartrate-Resistant Acid Phosphatase/metabolism , Time Factors , X-Ray DiffractionABSTRACT
Bioactive PEO (Plasma Electrolytic Oxidation) coatings were generated on Grade I commercially pure titanium for dentistry applications using a Ca/P-based electrolyte with added Si, Mg, Zn or F species. Surface characteristics, chemical composition and ion liberation of the coatings were characterized using SEM/EDS, X-ray diffraction, optical profilometry, contact angle and ICP-OES. Corrosion resistance (OCP and DC polarization) was evaluated in SBF. Osteoblastogenesis and osteoclastogenesis processes on PEO-coated Ti and non-coated Ti controls were assessed after 7â¯days and 5â¯days of cell culture, respectively. Monolayer formation and metabolic activity were evaluated for the MC3T3 preosteoblastic cell line. All PEO coatings favoured differentiation processes over proliferation and presented three times greater quantity of secreted collagen than non-coated Ti control. All coating enabled osteoclast differentiation, with differences in number and size of the osteoclasts between the materials.
Subject(s)
Coated Materials, Biocompatible/chemistry , Dental Implants , Plasma Gases/chemistry , Titanium/chemistry , Animals , Cell Differentiation/drug effects , Cell Line , Coated Materials, Biocompatible/pharmacology , Corrosion , Electrolytes/chemistry , Materials Testing , Mice , Microscopy, Electron, Scanning , Osteogenesis/drug effects , Oxidation-Reduction , Surface Properties , X-Ray DiffractionABSTRACT
BACKGROUND: Atypical carcinoids (AC) of the lung are rare intermediate-grade neuroendocrine neoplasms. Prognostic factors for these tumours are undefined. METHODS: Our cooperative group retrieved data on 127 patients operated between 1980 and 2009 because of an AC. Several clinical and pathological features were studied. RESULTS: In a univariable analysis, T-status (p=0.005), N-status (p=0.021), preoperative M-status (previously treated) (p=0.04), and distant recurrence developed during the outcome (p<0.001) presented statistically significant differences related to survival of these patients. In a multivariable analysis, only distant recurrence was demonstrated to be an independent risk factor for survival (p<0.001; HR: 13.1). During the monitoring, 25.2% of the patients presented some kind of recurrence. When we studied recurrence factors in a univariable manner, sublobar resections presented significant relationship with locoregional recurrence (p<0.001). In the case of distant recurrence, T and N status presented significant differences. Patients with preoperative M1 status presented higher frequencies of locoregional and distant recurrence (p=0.004 and p<0.001, respectively). In a multivariable analysis, sublobar resection was an independent prognostic factor to predict locoregional recurrence (p=0.002; HR: 18.1). CONCLUSIONS: Complete standard surgical resection with radical lymphadenectomy is essential for AC. Sublobar resections are related to locoregional recurrence, so they should be avoided except for carefully selected patients. Nodal status is an important prognostic factor to predict survival and recurrence. Distant recurrence is related to poor outcome.
Subject(s)
Carcinoid Tumor/pathology , Lung Neoplasms/pathology , Neoplasm Metastasis/pathology , Neoplasm Recurrence, Local/pathology , Biopsy , Bronchoscopy , Carcinoid Tumor/surgery , Female , Humans , Lung Neoplasms/surgery , Lymph Node Excision , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Prognosis , Risk Factors , Survival AnalysisABSTRACT
OBJECTIVES: Two types of ceramic coatings on commercially pure titanium for dental implant applications with different Ca/P ratios in the range from 1.5 to 4.0, and two different thicknesses (â¼5 and â¼15µm) were examined with the aim of underpinning the effect of coating composition, thickness and microstructure on the corrosion behavior and hydroxyapatite forming ability in SBF. METHODS: Bioactive coatings were formed on Ti by plasma electrolytic oxidation (PEO). The composition, structure, and morphology of the materials were characterized before and after the immersion in simulated body fluid solution (SBF) at 37°C for up to 4 weeks. All the materials were screened with respect to metal ion release into SBF. RESULTS: Only thick PEO coating with overstoichiometric Ca/P ratio of 4.0 exhibited capacity to induce the precipitation of hydroxyapatite over the short period of 1 week. Long term Ti(4+) ion release from all PEO-coated materials was 2-3 times lower than from the uncoated Ti. Metal ion release is attributed mostly to chemical dissolution of the coating at initial stages of immersion. SIGNIFICANCE: The long term stability was greater for thin PEO coating with overstoichiometric Ca/P ratio of 2.0, which exhibited â¼95ngcm(-2) of Ti(4+) ions release over 4 weeks. Thin PEO coatings present economically more viable option.
Subject(s)
Ceramics/chemistry , Dental Implants , Titanium/chemistry , Calcium Phosphates/chemistry , Coated Materials, Biocompatible/chemistry , Corrosion , Durapatite/chemistry , Electrochemistry , Microscopy, Electron, Scanning , Oxidation-Reduction , Porosity , Reproducibility of Results , Software , Surface PropertiesABSTRACT
A Plasma electrolytic oxidation (PEO) process was used to produce bioactive coatings on Ti. PEO coatings with Ca/P atomic ratio of 1.7 and 4.0 were fabricated and characterized with respect to their morphology, composition, and microstructure. AC and DC electrochemical tests were used to evaluate the effect of (i) organic additives (amino acids, proteins, vitamins, and antibiotics) in alpha-minimum essential medium (α-MEM) on electrochemical stability of noncoated and PEO-coated Ti and (ii) coating composition, microstructure, and corrosion behavior on the cell response in α-MEM. PEO-coated Ti showed higher corrosion resistance than the noncoated Ti in MEM with and without organic additives by an order of magnitude. The corrosion resistance in α-MEM decreased with time for nonmodified Ti and increased for PEO-coated Ti; the latter was because of the adsorption of the proteins in the coating pores which increased the diffusion resistance. The presence of Ca and P in titanium oxide coating at the Ca/P ratio exceeding that of any stoichiometric Ca-P-O and Ca-P-O-H compounds facilitates faster osteoblast cell adhesion.
Subject(s)
Coated Materials, Biocompatible/chemistry , Electrolysis/methods , Oxygen/chemistry , Titanium/chemistry , 3T3 Cells , Adsorption , Animals , Calcium/chemistry , Cell Adhesion , Cell Proliferation , Corrosion , Diffusion , Materials Testing/methods , Mice , Osteoblasts/cytology , Phosphates/chemistry , Surface PropertiesABSTRACT
Bioactive PEO coating on titanium with high Ca/P ratio was fabricated and characterized with respect to its morphology, composition and microstructure. Long-term electrochemical stability of the coating and Ti(4+) ion release was evaluated in artificial saliva. Influence of the lactic acid and fluoride ions on corrosion protection mechanism of the coated titanium was assessed using AC and DC electrochemical tests. The PEO-treated titanium maintained high passivity in the broad range of potentials up to 2.5 V (Ag/AgCl) for up to 8 weeks of immersion in unmodified saliva and exhibited Ti(4+) ion release <0.002 µg cm(-2) days(-1). The high corrosion resistance of the coating is determined by diffusion of reacting species through the coating and resistance of the inner dense part of the coating adjacent to the substrate. Acidification of saliva in the absence of fluoride ions does not affect the surface passivity, but the presence of 0.1 % of fluoride ions at pH ≤4.0 causes loss of adhesion of the coating due to inwards migration of fluoride ions and their adsorption at the substrate/coating interface in the presence of polarisation.
Subject(s)
Electrolysis , Plasma Gases , Saliva , Titanium/chemistry , Hydrogen-Ion Concentration , Microscopy, Electron, Scanning , Oxidation-Reduction , Spectrometry, X-Ray Emission , Surface Properties , X-Ray DiffractionABSTRACT
Transmission electron microscopy and supporting film analyses are used to investigate the changes in composition, morphology and structure of coatings formed on titanium during DC plasma electrolytic oxidation in a calcium- and phosphorus-containing electrolyte. The coatings are of potential interest as bioactive surfaces. The initial barrier film, of mixed amorphous and nanocrystalline structure, formed below the sparking voltage of 180 V, incorporates small amounts of phosphorus and calcium species, with phosphorus confined to the outer approximately 63% of the coating thickness. On commencement of sparking, calcium- and phosphorus-rich amorphous material forms at the coating surface, with local heating promoting crystallization in underlying and adjacent anodic titania. The amorphous material thickens with increased treatment time, comprising almost the whole of the approximately 5.7-microm-thick coating formed at 340 V. At this stage, the coating is approximately 4.4 times thicker than the oxidized titanium, with a near-surface composition of about 12 at.% Ti, 58 at.% O, 19 at.% P and 11 at.% Ca. Further, the amount of titanium consumed in forming the coating is similar to that calculated from the anodizing charge, although there may be non-Faradaic contributions to the coating growth.
Subject(s)
Titanium/chemistry , Electrolytes , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Oxidation-Reduction , Time FactorsABSTRACT
OBJETIVOS: Analizar la supervivencia de los subgrupos de tumores englobados bajo la estadificación T3 (invasores de pared, de mediastino y de bronquio principal). Estudiar las causas que justifican las diferencias halladas. PACIENTES Y MÉTODO: Estudio descriptivo, longitudinal, retrospectivo. 70 pacientes operados y estadificados como T3 (N0,N1, N2) M0 entre octubre de 2001 y octubre de 2006. Análisis estadístico Kapplan Meier y regresión de Cox RESULTADOS: 70 pacientes intervenidos, y repartidos en 40(57,1%) tumores invasores de pared, 17 (24,2%) de pleura mediastínica o pericardio parietal y 13 (18,5%) de bronquio principal. La supervivencia global acumulada a los cinco años fue del 41%. El grupo de pared tuvo una supervivencia a los cinco años del 40,7%,el mediastínico del 20% y el de bronquio principal del 68,5%. No existieron diferencias significativas entre los tres subgrupos(p<11%), probablemente por el tamaño muestral, pero sí un claro indicio de distintos comportamientos .Tuvieron significación estadística como factores pronósticos de supervivencia las variables afectación ganglionar y cirugía completa/incompleta. No tuvieron significación estadística las variables tamaño tumoral y estirpe histológica. Los tumores invasores mediastínicos (los de peor pronóstico),presentaron un porcentaje de N2 y cirugías incompletas superior al resto (variables con significación estadística).CONCLUSIONES: Debemos mejorar el porcentaje de cirugías completas en tumores T3 mediastínicos. Además, en este subgrupo, la exploración previa del mediastino debe ser considerada especialmente. Tumores en estadío T3N0 y T3N1 no han presentado diferencias significativas de supervivencia. Estudios posteriores deberían confirmar si deben continuar estatificándose en grupos distintos (IIB y IIIA)
OBJECTIVES: To study health-related quality of life (HRQL)of patients receiving home mechanical ventilation (HMV) for different causes using a new specific questionnaire (SRI).METHODS: Observational transversal multicentre trial in which 5 hospitals participated. Patients enrolled were scheduled for one only visit, where sociodemographic and clinical data were recorded, and the SRI questionnaire was administered. Comparison of the SRI results between diagnostic groups was performed. RESULTS: One hundred and fifteen patients (33 thoracic cage, 37 obesity hypoventilation syndromes, 18 neuromuscular, 12 tuberculosis sequelae, and 15 chronic obstructive pulmonary disease) were included. Global HRQL evaluation was similar for all disease groups. However, patients with an obstructive component in the pulmonary function tests resulted to have a different punctuation in several scales of the questionnaire. Neuromuscular patients had a worse punctuation on PF scale (26 ± 29 vs. 46 ± 25; p = 0.006) and required HMV during more hours of the day than the other diagnostic categories (10.8 ± 5 hours vs.8.2 ± 2.5 hours; p = 0.046). CONCLUSIONS: Although SRI is similarly impaired inpatients receiving HMV, the differences found between the diagnostic groups set different profiles for patients with obstructive, restrictive o neuromuscular diseases (AU)
Subject(s)
Humans , Male , Female , Aged , Mediastinal Neoplasms/mortality , Mediastinal Neoplasms/surgery , Bronchial Neoplasms/mortality , Bronchial Neoplasms/surgery , Survival Analysis , Neoplasm Staging , Retrospective Studies , Longitudinal Studies , PrognosisABSTRACT
El cáncer de pulmón no microcítico (CPNM) es la principal causa de muerte por cáncer en nuestro medio. El manejo de los pacientes con enfermedad avanzada basado en el mejor tratamiento de soporte sólo ofrece una mediana de supervivencia de 5 meses, con un 10% de supervivientes a 1 año. El tratamiento con quimioterapia puede marcar una diferencia y por ello es necesario conocer los nuevos avances en este sentido. En el metaanálisis publicado en 1995 por un grupo cooperativo que incluía 52 estudios con 9387 pacientes, se observó un beneficio significativo en todas las categorías de pacientes, sin que ningún régimen se mostrara superior. En los años 90 se introdujeron nuevos agentes antineoplásicos, con ensayos clínicos en los que se observaba eficacia con poca toxicidad. En contraste con las drogas antiguas, la combinación de cisplatino con alguna de éstas: vinorelbina, paclitaxel, docetaxel o gemcitabina demostró, no sólo alta tasa de respuesta, sino también beneficio en supervivencia. La combinaciones de platino con estas drogas han llegado a ser el tratamiento estándar en esta enfermedad. Actualmente se están desarrollando nuevos avances, como la investigación de marcadores genéticos para seleccionar el tratamiento individualizado, la introducción de tratamientos sin platino y terapias secuenciales, y la incorporación de agentes frente a dianas moleculares específicas (AU)
Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths for both men and women in our society. Patients with advanced-stage NSCLC managed with supportive care alone have a median survival of 5 months, and only 10% live 1 year. Treatment with chemotherapy can make a difference, and it is therefore of paramount importance to understand the latest data regarding effective treatment regimens for advanced NSCLC. In 1995, the NSCLC Collaborative Group published a meta-analysis of chemotherapy in lung cancer, which included 52 studies involving 9387 patients. Results favored cisplatin-containing chemotherapy in all patient categories, although no specific cisplatin regimen appeared superior. In the 1990s, several new antineoplastic agents were introduced. Early trials showed efficacy was often coupled with fewer adverse effects. In contrast to older cytotoxic agents, the combination of either vinorelbine, paclitaxel, docetaxel or gemcitabine, with cisplatin demonstrated not only impressive response rates, but also improved survival. These combination regimens of platinum compounds with third-generation chemotherapy agents have become the standard of palliative care in this setting. Actually, new approaches are being developed. Some areas of interest include investigation into the use of molecular markers to select therapy for individual patients, research into nonplatinum regimens and sequential therapy, and the incorporation of novel molecular-targeted agents into chemotherapy regimens. The results in many phase III trials are encouraging (AU)
Subject(s)
Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic useABSTRACT
La estrategia de tratamiento más utilizada en el cáncer de pulmón no microcítico (CPNM) avanzado es la quimioterapia, concretamente la combinación de dos drogas, principalmente cisplatino con gemcitabina, vinorelbina, taxanos, irinotecan. En el pasado se han hecho intentos en vano de revertir la resistencia a la quimioterapia. La supervivencia en este estadio no suele superar los 8-10 meses con el tratamiento convencional. En el presente, intentos para superar estos resultados se focalizan en la farmacogenómica, con el objetivo de individualizar la quimioterapia basado en aspectos de biología molecular, como los polimorfismos, mutaciones genéticas, y sobreexpresión de genes que pueden funcionar como dianas de los fármacos. La evidencia indica que algunos marcadores genéticos pueden ser predictivos de resistencia a la quimioterapia. Uno de los objetivos en investigación translacional es investigar la aplicación clínica de los sistemas de reparación del DNA. Algunos genes como ERCC1, XPD polymorphisms. RRM1, BCRA1, etc se relacionan con resistencia a cisplatino y otras drogas (AU)
The most commonly used chemotherapy strategy in advanced Non small cell lung cancer (NSCLC) today is the combination of two drugs, mainly cisplatin with another drug (gemcitabine, vinorelbine, taxanes, irinotecan). In the last decade attempts have been made to overcome chemotherapy resistance without benefit in outcomes. There is a plateau in the results which seems unable to progress beyond the frontier of 8-10 months of median survival. At present, research in cancer survival is focused on translational pharmacogenomics, with the goal of providing individualized CT based on different genetic traits, such a polymorphisms, gen mutation and overexpresion of drug target gene transcripts, and several molecular assays can been used to tailor chemotherapy in the care of lung cancer patients. Accumulated evidence indicates that many genetic markers are related to chemotherapy resistance. One of the most important goals in translational research is to investigate the clinical use of the DNA repair pathways. Several genes such as ERCC1, XPD polymorphisms. RRM1, BCRA1, etc are related to cisplatin and other drugs resistance (AU)
