Role of the RAD51 G172T polymorphism in the clinical outcome of cervical cancer patients under concomitant chemoradiotherapy

INTRODUCTION: Cervical cancer is one of the most common cancers diagnosed in women worldwide. Mammalian cells are constantly exposed to a wide variety of genotoxic agents from both endogenous and exogenous sources. The RAD51 protein is required for meiotic and mitotic recombination and plays a central role in homology-dependent recombinational repair of double-strand breaks (DSBs). Given the functional relevance of the DNA repair system on carcinogenesis, potential associations between genetic polymorphisms of DNA repair genes, cancer risk and response to therapy have been intensively evaluated. This is the first study evaluating the role of the RAD51 G172T genetic variants in cancer prognosis and clinical outcome of cervical cancer patients. MATERIAL AND METHODS: We analyzed RAD51 G172T polymorphism genotypes in cervical cancer patients who underwent a platinum-based chemotherapy in combination with radiotherapy. Genotyping was performed by Taqman™ Allelic Discrimination methodology. RESULTS AND DISCUSSION: Concerning the overall survival rates found using Kaplan-Meier method and Log Rank Test, we observed that the mean survival rates were statistically different according to the patients RAD51 genotypes. The group of patients carrying the T allele present a higher mean survival rate than the other patients (102.3months vs. 86.4months, P=0.020). Using the Cox regression analysis, we found an increased overall survival time for T-carrier patients, when compared with GG genotype, with tumor stage, age and presence of lymph nodes as covariates [hazard ratio (HR), 0.373; 95% CI, 0.181-0.770; P=0.008]. Among patients (n=193), RAD51 genotype frequency distributions were not under the influence of clinicopathologic characteristics, namely, treatment response (P=0.508), recurrence (P=0.150) and tumor stage (P=0.250). CONCLUSIONS: This is the first study evaluating the role of the RAD51 G172T genetic variants in cancer prognosis and clinical outcome of cervical cancer patients. Our results indicate an influence of the RAD51 genetic variants in overall survival of cervical cancer. Thereby, RAD51 G172T genotypes may provide additional prognostic information in cervical cancer patients who underwent cisplatin-based chemotherapy in combination with radiotherapy

Towards efficient ciprofloxacin adsorption using magnetic hybrid nanoparticles prepared with κ-, ι-, and λ-carrageenan

The efficient removal of the antibiotic ciprofloxacin (CIP) from aqueous samples using magnetic nanosorbents prepared using three sulfated polysaccharides, κ-, ι- and λ-carrageenan and an alkoxysilane agent containing a reactive epoxide ring is described. The prepared nanosorbents were characterized in detail using FTIR spectroscopy, solid-state 29Si and 13C NMR spectroscopy and elemental microanalysis. The synthesis method was more effective for incorporating higher amounts of κ-carrageenan in the siliceous shells. Although being less sulfated, κ-carrageenan is cheaper than the other carrageenan tested. The CIP adsorption was a cooperative process, well described by the Dubinin–Radushkevich isotherm, with maximum adsorption capacities of 878, 969 and 865 mg/g for κ-, ι- and λ-carrageenan sorbents, respectively. Overall, the produced magnetic nanosorbents are among the best magnetic systems with high adsorptive efficiency for CIP. It is suggested that protonated CIP molecules are exchanged with ester sulfate counterions of carrageenan at the particles’ surface as the main pathway for CIP adsorption. The adsorption process was exothermic and entropically favorable for the three sorbents. However, at 298 K, the adsorption was spontaneous for κ-carrageenan-based sorbents and non-spontaneous for ι- and λ-carrageenan particles. The magnetic sorbents could be reused and maintained their ability towards CIP removal up to four cycles. The removal efficiency in wastewater was enhanced with the sorbent dose. Graphical abstract: [Figure not available: see fulltext.] Magnetic carrageenan nanosorbents were prepared using three carrageenan polysaccharides (κ-, ι-, and λ-carrageenan). The resulting magnetic particles removed the antibiotic ciprofloxacin efficiently from ultra-pure water and wastewater samples. Magnetic features enabled the fast magnetic separation of the nanosorbents from water.publishe

Inducibility of Atrial Fibrillation During Electrophysiologic Evaluation is Associated with Increased Dispersion of Atrial Refractoriness

The impact of atrial dispersion of refractoriness (Disp_A) in the inducibility and maintenance of atrial fibrillation (AF) has not been fully resolved. AIM: To study the Disp_A and the vulnerability (A_Vuln) for the induction of self-limited (<60 s) and sustained episodes of AF. METHODS AND RESULTS: Forty-seven patients with paroxysmal AF (PAF): 29 patients without structural heart disease and 18 with hypertensive heart disease. Atrial effective refractory period (ERP) was assessed at five sites--right atrial appendage and low lateral right atrium, high interatrial septum, proximal and distal coronary sinus. We compared three groups: group A - AF not inducible (n=13); group B - AF inducible, self-limited (n=18); group C - AF inducible, sustained (n=16). Age, lone AF, hypertension, left atrial and left ventricular (LV) dimensions, LV systolic function, duration of AF history, atrial flutter/tachycardia, previous antiarrhythmics, and Disp_A were analysed with logistic regression to determine association with A_Vuln for AF inducibility. The ERP at different sites showed no differences among the groups. Group A had a lower Disp_A compared to group B (47+/-20 ms vs 82+/-65 ms; p=0.002), and when compared to group C (47+/-20 ms vs 80+/-55 ms; p=0.008). There was no significant difference in Disp_A between groups B and C. By means of multivariate regression analysis, the only predictor of A_Vuln was Disp_A (p=0.04). Conclusion: In patients with PAF, increased Disp_A represents an electrophysiological marker of A_Vuln. Inducibility of both self-limited and sustained episodes of AF is associated with similar values of Disp_A. These findings suggest that the maintenance of AF is influenced by additional factors

Proposta metodológica para a geração de modelo de elevação digital a partir de cartas topográficas: uma abordagem no contexto do projeto GeoDegrade.

O projeto GeoDegrade tem como objetivo desenvolver geotecnologias para a identificação e o monitoramento de níveis de degradação em pastagens, sendo que um dos métodos contemplados no projeto é a integração de plataformas de informações de variáveis biofísicas. Por meio da sobreposição do MDE e suas informações intrínsecas (classes de declividades, comprimento das vertentes e áreas das vertentes) às demais plataformas de informação (mapa de solo, uso e cobertura vegetal e balanço hídrico da região) é possível descrever o potencial de erodibilidade do solo e sua influência nos processos de degradação das pastagens.bitstream/item/83479/1/034-12.pd

Respiratory Morbidity and Exposure to Inhalable Particles in the City of Lisbon

Introdução: Os efeitos adversos das partículas em suspensão na saúde humana expressam-se sob efeitos agudos e crónicos, não existindo nenhum limiar abaixo do qual se considere que a exposição a partículas não origine efeitos na saúde da população. À semelhança de outras capitais europeias, a cidade de Lisboa apresenta elevados níveis de partículas, principalmente nas áreas de maior tráfego. Objectivo: Neste estudo procurou-se analisar os efeitos na saúde humana decorrentes da exposição ambiental a partículas em suspensão na atmosfera (PM10 e PM2.5). Metodologia: O estudo centrou-se nos efeitos das partículas inaláveis na saúde respiratória da população infanto-juvenil residente em Lisboa. Para o efeito, foram caracterizados os níveis de partículas (PM10 e PM2.5) em Lisboa e procedeu-se a uma avaliação da morbilidade respiratória, utilizando métodos indirectos relacionados com a procura e utilização dos serviços de saúde em situação de urgência, tendo como base os atendimentos da Urgência Pediátrica de um Hospital de Lisboa. Resultados: Verificou-se que um terço das urgências pediátricas hospitalares é de natureza respiratória, destacando-se quatro principais patologias: infecção aguda das vias aéreas superiores, infecção aguda das vias aéreas inferiores, asma e pneumonia. Os modelos estatísticos explicativos foram desenvolvidos com vista a aferir as variáveis ambientais mais relevantes para avaliar os impactes da poluição atmosférica por PM na saúde respiratória infantil, identificando-se um desfasamento temporal, de poucos dias, entre as ocorrências de elevadas concentrações de partículas e os efeitos respiratórios. Conclusão: Nestes modelos a temperatura mínima surge como importante variável explicativa, assim como as concentrações de partículas medidas em estações de fundo (mais representativas dos níveis de concentrações de PM de zonas residenciais) em detrimento das estações de tráfego. Foi evidente uma relação entre a zona de residência das crianças com problemas respiratórios atendidas na urgência e as áreas da cidade com maiores níveis de partículas