Effect of Melatonin as an Antioxidant Drug to Reverse Hepatic Steatosis: Experimental Model.

Introduction: The hepatic steatosis of the nonalcoholic origin or NAFLD is increasing at present, particularly in Western countries, parallel to the increase in obesity, constituting one of the most prevalent hepatic processes in the Western society. Melatonin has been successfully tested in experimental models in mice as a drug capable of reversing steatosis. The effect of melatonin on fat metabolism can be summarized as a decrease in lipid peroxidation and a decrease in oxidative stress, biochemical phenomena intimately related to fat deposition in the hepatocyte. There are hardly any studies in large animals. Objective: In this study, we investigate the effects of melatonin administered orally at a dose of 10 mg/kg/day to reverse established hepatic steatosis induced by a special diet in a porcine animal model. Materials and Methods: We analyze the parameters of oxidative stress: malondialdehyde (MDA), 4-hydroxyalkenals (4-HDA), and carbonyls, degree of fat infiltration (analyzed by direct vision by a pathologist and by means of a computer program of image treatment), and serological parameters of lipid metabolism and hepatic damage. These parameters were analyzed in animals to which hepatic steatosis was induced by means of dietary modifications. Results: We have not been able to demonstrate globally a beneficial effect of melatonin in the improvement or reversal of liver steatosis once established, induced by diet in a porcine animal model. However, we have found several signs of improvement at the histological level, at the level of lipid metabolism, and at the level of oxidative stress parameters. We have verified in our study that, in the histological analysis of the liver sample by means of the program image treatment (free of subjectivity) of the animals that continue with the diet, those that consume melatonin do not increase steatosis as much as those that do not consume it significantly (p=0.002). Regarding the parameters of oxidative stress, MDA modifies in a significant manner within the group of animals that continue with the diet and take melatonin (p=0.004). As for lipid metabolism, animals that maintain the steatotic diet and take melatonin lower total and LDL cholesterol levels and increase HDL levels, although these results do not acquire statistical significance. Conclusions: In this study, it has not been possible to demonstrate a beneficial effect of melatonin in the improvement or reversal of liver steatosis once established and induced by diet in the porcine model. It is true that signs of improvement have been found at the histological level, at the level of lipid metabolism, and at the level of oxidative stress phenomena, when comparing animals with established steatosis that are treated with melatonin with those who do not take it. This work is the first study conducted in a large animal model in which the effect of melatonin is studied as a treatment in the reversal of established hepatic steatosis.

Gas chromatography coupled to tunable pulsed glow discharge time-of-flight mass spectrometry for environmental analysis.

A tuneable microsecond pulsed direct current glow discharge (GD)-time-of-flight mass spectrometer MS(TOF) developed in our laboratory was coupled to a gas chromatograph (GC) to obtain sequential collection of the mass spectra, at different temporal regimes occurring in the GD pulses, during elution of the analytes. The capabilities of this set-up were explored using a mixture of volatile organic compounds of environmental concern: BrClCH, Cl(3)CH, Cl(4)C, BrCl(2)CH, Br(2)ClCH, Br(3)CH. The experimental parameters of the GC-pulsed GD-MS(TOF) prototype were optimized in order to separate appropriately and analyze the six selected organic compounds, and two GC carrier gases, helium and nitrogen, were evaluated. Mass spectra for all analytes were obtained in the prepeak, plateau and afterpeak temporal regimes of the pulsed GD. Results showed that helium offered the best elemental sensitivity, while nitrogen provided higher signal intensities for fragments and molecular peaks. The analytical performance characteristics were also worked out for each analyte. Absolute detection limits obtained were in the order of ng. In a second step, headspace solid phase microextraction (HS SPME), as sample preparation and preconcentration technique, was evaluated for the quantification of the compounds under study, in order to achieve the required analytical sensitivity for trihalomethanes European Union (EU) environmental legislation. The analytical figures of merit obtained using the proposed methodology showed rather good detection limits (between 2 and 13 microg L(-1) depending on the analyte). In fact, the developed methodology met the EU legislation requirements (the maximum level permitted in tap water for the "total trihalomethanes" is set at 100 microg L(-1)). Real analysis of drinking water and river water were successfully carried out. To our knowledge this is the first application of GC-pulsed GD-MS(TOF) for the analysis of real samples. Its ability to provide elemental, fragments and molecular information of the organic compounds is demonstrated.

Critical comparison of automated purge and trap and solid-phase microextraction for routine determination of volatile organic compounds in drinking waters by GC-MS.

The use of two automated sample preparation techniques, solid-phase microextraction (SPME) and purge and trap (P&T) systems are critically compared for the GC-MS determination of eight volatile organic compounds (VOCs), including trihalomethanes (THMs), in drinking water samples. Compounds chosen for the comparison are regulated by Spanish and European official guidelines for drinking waters. Experimental parameters investigated for the two sample preparation techniques included SPME type of fibers, SPME modality, P&T gas flow, extraction and desorption times and desorption temperatures. Thus, optimal experimental conditions have been worked out for the SPME and P&T techniques. Under such optimised conditions, detection limits, precision and accuracy were evaluated. Both methods fulfilled the values that the official guidelines establish. The P&T-GC-MS method offers LDs ranged from 0.004 to 0.2 ng mL(-1), repeatabilities below 6% and recoveries between 81 and 117%; while LDs ranging from 0.008 to 0.7 ng mL(-1), 1-12% R.S.D. and recoveries from 80 to 119% were achieved with the SPME-GC-MS method. Finally, we chose P&T-GC-MS method as the best for this determination and we validate this methodology by its application to the analysis of an Aquacheck Interlaboratory Exercise.

[Minimally invasive breast surgery. Breast reconstruction using pure muscular latissimus dorsi flap]. / Cirugía mamaria mínimamente invasiva: reconstrucción mamaria mediante colgajo muscular puro del gran dorsal.

INTRODUCTION: Minimally invasive surgical techniques have extended to all the fields of surgery. Breast surgery can also benefit from these concepts because of their special characteristics, reduction of aggressiveness, avoiding or hiding scars. The aim of our work is to introduce a new surgical approach for the resection of a large volume of breast parenchyma, including complete subcutaneous mastectomy and reconstruction using a pure muscular latissimus dorsi flap, with or without prosthetic material, through a minimal cutaneous incision. PATIENTS AND METHOD: Retrospective analysis of our series of 5 cases using our surgical technique which allows us to establish proper indications. We analyse the technical details, complications and results. RESULTS: Five patients were operated using this technique (1 giant hamartoma, 1 multicentred in situ carcinoma with Paget's disease, 1 multicentred infiltrating carcinoma and 2 malignant tumours arising in the external part of the breast). We performed oncological resections (2 partial resections and 3 complete subcutaneous mastectomies) including sentinel lymph node biopsy or total axillary lymphadenectomy. After a mean follow-up of 10 months no local relapses were found and the cosmetic results were excellent. CONCLUSIONS: Minimally invasive surgical techniques through a posterior axillary line vertical incision enable total or partial subcutaneous mastectomy and a breast reconstruction, using muscular flaps or prosthetic material, to be performed.

Cirugía mamaria mínimamente invasiva: reconstrucción mamaria mediante colgajo muscular puro del gran dorsal / Minimally invasive breast surgery. Breast reconstruction using pure muscular latissimus dorsi flap

Introducción. Las técnicas mínimamente invasivas se han extendido a todos los campos de la cirugía, la cirugía mamaria es quizá la cirugía que más se debería beneficiar de estos conceptos, por sus características especiales, reduce la agresión quirúrgica y elimina u oculta cicatrices. El propósito de nuestro trabajo es presentar una nueva técnica quirúrgica para la resección de grandes volúmenes de tejido mamario, incluida la mastectomía subcutánea completa, y reconstrucción mediante un colgajo del músculo gran dorsal con o sin material protésico, a través de una mínima incisión cutánea. Pacientes y metodo. Análisis retrospectivo de nuestra serie de 5 casos clínicos intervenidos con esta técnica, que nos ha permitido ponerla a punto y establecer las indicaciones. Analizamos los detalles técnicos, las complicaciones y los resultados. Resultados. Hemos intervenido a 5 pacientes mediante esta técnica quirúrgica (1 con hamartoma gigante, 1 con carcinoma in situ multicéntrico con enfermedad de Paget, 1 con tumor mamario maligno multicéntrico y 2 con tumoraciones malignas únicas de cuadrantes externos) practicando resecciones oncológicas suficientes (2 resecciones parciales mamarias y 3 mastectomías subcutáneas) e incluían biopsia de ganglio centinela o linfadenectomía axilar completa. Tras un período de seguimiento medio de 10 meses no ha habido recidivas locales y el resultado estético es excelente. Conclusiones. La técnica mínimamente invasiva, a través de una incisión vertical en línea axilar posterior, permite realizar una resección mamaria parcial o completa, así como una reconstrucción inmediata mediante tejido autólogo o material protésico (AU)

Introduction. Minimally invasive surgical techniques have extended to all the fields of surgery. Breast surgery can also benefit from these concepts because of their special characteristics, reduction of aggressiveness, avoiding or hiding scars. The aim of our work is to introduce a new surgical approach for the resection of a large volume of breast parenchyma, including complete subcutaneous mastectomy and reconstruction using a pure muscular latissimus dorsi flap, with or without prosthetic material, through a minimal cutaneous incision. Patients and method. Retrospective analysis of our series of 5 cases using our surgical technique which allows us to establish proper indications. We analyse the technical details, complications and results. Results. Five patients were operated using this technique (1 giant hamartoma, 1 multicentred in situ carcinoma with Paget's disease, 1 multicentred infiltrating carcinoma and 2 malignant tumours arising in the external part of the breast). We performed oncological resections (2 partial resections and 3 complete subcutaneous mastectomies) including sentinel lymph node biopsy or total axillary lymphadenectomy. After a mean follow-up of 10 months no local relapses were found and the cosmetic results were excellent. Conclusions. Minimally invasive surgical techniques through a posterior axillary line vertical incision enable total or partial subcutaneous mastectomy and a breast reconstruction, using muscular flaps or prosthetic material, to be performed (AU)