Highly sensitive electrochemical immunosensor using a protein-polyvinylidene fluoride nanocomposite for human thyroglobulin.

The highly sensitive detection of serum thyroglobulin (Tg) is essential in the post-treatment follow-up of patients with differentiated thyroid cancer undergoing total or partial thyroidectomy and radioactive iodine ablation and requires sensitive, accurate and stable methods. This work proposes an electrochemical immunosensor for the detection of serum Tg antigen, making use of innovative nanocomposites including polyvinylidene fluoride (PVDF) microparticles coated with streptavidin (MP) and gold nanoparticles (AuNPs). The functionalized polymer matrices were characterized by UV-Vis, FTIR, XPS, SEM, dynamic light scattering, and free surface energy. Immobilization of biotin-labeled anti-thyroglobulin monoclonal antibodies was achieved by binding these to the polymer nanocomposite via streptavidin proteins. The analytical response was measured in quintuplicate and had a linear profile from 2.0 to 10.0 ng/mL Tg, with r2 of 0.985. The limits of detection and quantification were excellent, equal to 0.015 and 0.047 ng/mL, respectively. In addition, the recovery factor was equal to 95.4% (1.0 ng/mL Tg). Overall, the innovative polymer-based nanocomposite used herein enabled the production of an electrochemical-based immunosensor with excellent sensitivity, selectivity, and reproducibility. It evidenced the remarkable potential of determining low levels of Tg in in vitro assays, thereby suggesting that it may be considered for the analyzes of serum patients.

Enteral nutrition discontinuation and outcomes in general critically ill patients

OBJECTIVE: To determine the relationship between enteral nutrition discontinuation and outcome in general critically ill patients. MATERIALS AND METHODS: All patients admitted to a mixed intensive care unit in a tertiary care hospital from May-August 2009 were screened for an indication for enteral nutrition. Patients were followed up until leaving the intensive care unit or a maximum of 28 days. The gastrointestinal failure score was calculated daily by adding values of 0 if the enteral nutrition received was identical to the nutrition prescribed, 1 if the enteral nutrition received was at least 75% of that prescribed, 2 if the enteral nutrition received was between 50-75% of that prescribed, 3 if the enteral nutrition received was between 50-25% of that prescribed, and 4 if the enteral nutrition received was less than 25% of that prescribed. RESULTS: The mean, worst, and categorical gastrointestinal failure scores were associated with lower survival in these patients. Age, categorical gastrointestinal failure score, type of admission, need for mechanical ventilation, sequential organ failure assessment, and Acute Physiologic and Chronic Health Evaluation II scores were selected for analysis with binary regression. In both models, the categorical gastrointestinal failure score was related to mortality. CONCLUSION: The determination of the difference between prescribed and received enteral nutrition seemed to be a useful prognostic marker and is feasible to be incorporated into a gastrointestinal failure score.

Análise comparativa entre ultrassom terapêutico e auto-hemoterapia no tratamento de lesão muscular em modelo animal / Comparative analyses of therapeutic ultrasound and autohemotherapy on treatment of muscle injury in animal model

Introdução: Este estudo teve como objetivo comparar os efeitos do ultrassom terapêutico e da auto-hemoterapia no tratamento da lesão muscular. Material e métodos: Foram utilizados 24 ratos Wistar, divididos aleatoriamente em quatro grupos: G1: Ratos sem lesão muscular; G2: Ratos com lesão muscular sem tratamento; G3:Ratos com lesão muscular e tratamento com ultrassom pulsado (0.8W/cm2); G4: Ratos com lesão muscular e tratamento com auto--hemoterapia. A lesão muscular foi induzida por um trauma único no gastrocnêmio. O tratamento foi realizado durante 7 dias e os animais foram eutanasiados por decapitação e o tecido muscular ao redor da lesão foi removido cirurgicamente para a realização das análises bioquímicas. Dentre os marcadores bioquímicos foram analisados ânion superóxido como marcador na produção de espécies reativas de oxigênio, e catalase como marcador de enzimas antioxidantes. Resultados: O grupo 2 apresentou diferença significativa em relação ao grupo 1 tendo aumentado o estresse oxidativo, e o grupo 3 apresentou diminuição do estresse oxidativo estatisticamente significativa em relação ao grupo 2, o grupo 4 não apresentou diferença significativa. Conclusão: Nota-se que a auto-hemoterapia não apresentou resultados satisfatórios no tratamento de lesão muscular,ao contrário do ultrassom, que diminuiu os marcadores de estresse oxidativo sendo eficaz no tratamento de lesão muscular.

Introduction: This study aimed to compare the effects of therapeutic ultrasound and autohemotherapy to treat muscle injury. Methods: Twenty four Wistar rats were randomly divided into four groups: G1: Rats with no muscle injury; G2: Rats with muscle injury without treatment; G3: Rats with muscle injury and treatment using pulsed ultrasound (0.8 W/cm²); G4: Rats with muscle injury and treatment using autohemotherapy. The muscle injury was inducedby a single trauma on the gastrocnemius. The treatment was carriedout during 7 days and the animals were euthanized by decapitation and the muscle tissue around the injury was surgically removed toper form biochemistry analyses. Among the biochemical markerswere analyzed superoxide anion as a marker of reactive oxygen species production and catalase as antioxidant enzymes. Results: Group 2showed significant difference compared to group 1 and increased oxidative stress, and group 3 showed a reduction of statistically significant oxidative stress compared to group 2, group 4 showedno significant difference. Conclusion: Was observed that the muscle injury treatment using autohemotherapy has no satisfactory results.On the other hand, ultrasound therapy reduced the oxidative stress markers and has proved effective in treating muscle injury.

Antioxidant activity of new ruthenium compounds.

Many biological properties have been attributed to ruthenium complexes including anti-tumor activity and the attenuation of reperfusion damage and infarct size. In this work, we characterize the antioxidant activity of trans-[RuCl2(nic)4] where nic is 3-pyridinecarboxylic acid and trans-[RuCl2(i-nic)4] where i-nic is 4-pyridinecarboxylic acid by (i) evaluation of total antioxidant potential (TRAP); (ii) prevention of DNA damage induced by hydrogen peroxide using the alkaline comet assay; and (iii) the prevention of lipid peroxidation and cell death induced by iron in liver slices. Our results suggest that nic has stronger antioxidant potential when compared to the i-nic. Higher doses (above 200 microM) of these compounds gave genotoxic effects, but the antioxidant potential could be obtained with the use lower doses (0.1-10 microM).