Gold nanoparticles alter parameters of oxidative stress and energy metabolism in organs of adult rats.

This study evaluated the parameters of oxidative stress and energy metabolism after the acute and long-term administration of gold nanoparticles (GNPs, 10 and 30 nm in diameter) in different organs of rats. Adult male Wistar rats received a single intraperitoneal injection or repeated injections (once daily for 28 days) of saline solution, GNPs-10 or GNPs-30. Twenty-four hours after the last administration, the animals were killed, and the liver, kidney, and heart were isolated for biochemical analysis. We demonstrated that acute administration of GNPs-30 increased the TBARS levels, and that GNPs-10 increased the carbonyl protein levels. The long-term administration of GNPs-10 increased the TBARS levels, and the carbonyl protein levels were increased by GNPs-30. Acute administration of GNPs-10 and GNPs-30 increased SOD activity. Long-term administration of GNPs-30 increased SOD activity. Acute administration of GNPs-10 decreased the activity of CAT, whereas long-term administration of GNP-10 and GNP-30 altered CAT activity randomly. Our results also demonstrated that acute GNPs-30 administration decreased energy metabolism, especially in the liver and heart. Long-term GNPs-10 administration increased energy metabolism in the liver and decreased energy metabolism in the kidney and heart, whereas long-term GNPs-30 administration increased energy metabolism in the heart. The results of our study are consistent with other studies conducted in our research group and reinforce the fact that GNPs can lead to oxidative damage, which is responsible for DNA damage and alterations in energy metabolism.

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.

In vitro effects of silver nanoparticles on the mitochondrial respiratory chain.

Silver has been used for years in medicine; it has known antimicrobial properties. Additionally, silver has been used in water and air filtration to eliminate microorganisms, and, more recently, as a biocide to prevent infections in burns. In contact with the human body, nanoparticles can elicit a spectrum of tissue responses such as the generation of reactive oxygen species, decreased function of mitochondria and even cell death. Mitochondries are intracellular organelles that play a crucial role in ATP production. In the present work, we evaluate the in vitro effect of silver nanoparticles (AgN) on the activities of mitochondrial respiratory chain complexes from the brain, skeletal muscle, heart, and liver of rats. Our results demonstrated that AgN (10, 25, and 50 mg l(-1)) decreases the activity of mitochondrial respiratory chain complexes I, II, III, and IV from all tissues.

Therapeutic effects of iontophoresis with gold nanoparticles in the repair of traumatic muscle injury.

Studies have shown the benefits of gold nanoparticles (GNPs) in muscle and epithelial injury models. In physiotherapy, the use of the microcurrent apparatus is associated with certain drugs (Iontophoresis) to increase the topical penetration and to associate the effects of both therapies. Therefore, the objective of this study was to investigate the effects of iontophoresis along with GNPs in the skeletal muscle of rats exposed to a traumatic muscle injury. We utilised 50 Wistar rats randomly divided in to five experimental groups (n = 10): Control group (CG); Muscle injury group (MI); MI + GNPs (20 nm, 30 mg kg-1); MI + Microcurrent (300 µA); and MI + Microcurrent + GNPs. The treatment was performed daily for 7 days, with the first session starting at 24 h after the muscle injury. The animals were sacrificed and the gastrocnemius muscle was surgically removedand stored for the proper evaluations. The group that received iontophoresis with GNPs showed significant differences in inflammation and oxidative stress parameters and in the histopathological evaluation showed preserved morphology. In addition, we observed an improvement in the locomotor response and pain symptoms of these animals. These results suggest that the association of boththerapies accelerates the inflammatory response of the injured limb.

Effects of phonophoresis with ibuprofen associated with gold nanoparticles in animal model of traumatic muscle injury.

The repair process consists of molecular and cellular events that can be accelerated by specific therapies. Considering this, the objective of this study was to evaluate the effects of ibuprofen phonophoresis associated with gold nanoparticles in the animal model of traumatic muscle injury. Was used 80 male wistar rats divided into eight groups: Sham; Muscle injury (MI); MI + therapeutic pulsed ultrasound (TPU); MI + Ibuprofen (IBU); MI + GNPs; MI + TPU+ IBU; MI + TPU + GNPs and MI + TPU + IBU + GNPs. The lesion in the gastrocnemius was performed by a single direct trauma impact on the injured press. The animals were treated with pulsed ultrasound and the gel with gold nanoparticles and/or ibuprofen. The treatment was applied daily for 5 days and the first session was 12 h after the muscle injury. The gastrocnemius muscle was surgically removed for analyzes biochemical, molecular and histological. In the analyzes only the MI + TPU + IBU + GNPs group showed a reduction in TNF-a and IL-1 levels, with a concomitant increase in the levels of anti-inflammatory cytokines. In the analysis of oxidative stress, only the MI + TPU + IBU + GNPs group presented a reversal of the condition when compared to the MI group. In the histological analysis, the MI group presented a large cell infiltrate and a centralized nucleus and only the MI + TPU + IBU + GNPs group showed a structural improvement, also in the pain results the MI + TPU + IBU + GNPs showed a significant difference in comparison to the MI group (p<0.01). We believe that the effects of phonophoresis with anti-inflammatory drugs associated with gold nanoparticles may potentiate the reduction of the inflammatory response and regulate the cellular redox state.

Effects of phonophoresis with gold nanoparticles on oxidative stress parameters in a traumatic muscle injury model.

The aim of this study was to evaluate the effects of therapeutic pulsed ultrasound with gold nanoparticles on oxidative stress parameters after traumatic muscle injury in Wistar rats. The animals were randomly divided into nine groups (n = 6 each): sham (uninjured muscle); muscle injury without treatment; muscle injury and treatment with dimethyl sulfoxide (15 mg/kg); muscle injury and treatment with gold nanoparticles (27 µg); muscle injury and treatment with dimethyl sulfoxide + gold nanoparticles (Plus); muscle injury and therapeutic pulsed ultrasound; muscle injury and therapeutic pulsed ultrasound + dimethyl sulfoxide; muscle injury and therapeutic pulsed ultrasound + gold nanoparticles; and muscle injury and therapeutic pulsed ultrasound + Plus. Gastrocnemius injury was induced by a single-impact blunt trauma. Therapeutic pulsed ultrasound (6-min application, frequency 1.0 MHz, intensity 0.8 W/cm(2)) was used 2, 12, 24, and 48 h after trauma. Mitochondrial superoxide generation, lipid peroxidation, and protein carbonylation, and the activities of superoxide dismutase, glutathione peroxidase, and catalase were evaluated. The increase in the superoxide production and TBARS and carbonyl levels observed in the control group after muscle damage were reduced in animals exposed to therapeutic pulsed ultrasound plus nanoparticles. Similarly, antioxidants enzymes showed a decreased activity with the same treatment. Our work suggest that therapeutic pulsed ultrasound + dimethyl sulfoxide + gold nanoparticles has beneficial effects on the muscle healing process by inducing a decrease in oxidative stress parameters and most likely decreasing the deleterious effects of the inflammatory response.

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.

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.

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).

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.