Evaluation of immune stimulatory products for whiteleg shrimp (Penaeus vannamei) by a metabolomics approach.

The use of probiotics, prebiotics and dietary fiber has become a common practice in shrimp aquaculture as alternatives to antibiotic treatment. However, not much is known about the metabolic mechanisms underlying the effects of probiotics and immunostimulant used in shrimp aquaculture. In this study, a gas chromatography-mass spectrometry (GC-MS) based metabolomics approach was used to characterize metabolite profiles of haemolymph and gills of whiteleg shrimp (Penaeus vannamei) exposed to four treatments (cellulose fiber, probiotics with Vibrio alginolyticus, a combination of cellulose fiber and V. alginolyticus and a control treatment). The cellulose fiber was administrated as a feed additive (100 mg⋅Kg-1 feed), while the probiotics was applied in the water (105 UFC⋅mL-1 culture water). The results showed significant differences in haemolymph metabolite profiles of immune stimulated treatments compared to the control and among treatments. The combination of cellulose fiber and probiotics resulted in greater differences in metabolic profiles, suggesting a better immune stimulation with this approach. The changes in haemolymph metabolome of treated shrimp reflected several biochemical pathway modifications, including changes in amino acid and fatty acid metabolism, disturbances in energy metabolism and antimicrobial activity and stress responses. For gill tissues, significant differences were only found in lactic acid between the probiotic group and the control. Among the altered metabolites, the increases of itaconic acid in haemolymph, and lactic acid in both haemolymph and gill tissues of immune-stimulated suggest the potential use of these metabolites as biomarkers for health assessment in aquaculture.

A simple in vitro method to evaluate the toxicity of functional additives used in shrimp aquaculture.

To mitigate the economic losses provoked by disease outbreaks, shrimp producers employ therapeutic additives. However, important issues such as the toxicity of these products on shrimp are not always considered. In vivo toxicity assays require a lot of time and large economic and physical resources. Here, we describe an in vitro procedure to evaluate the toxicity of functional additives, used in the production of shrimp Penaeus vannamei. This method adapted the cell viability assay based on the reduction of tetrazolium salts (MTT) to primary cell cultures of shrimp hemocytes. •A simple and reliable tool that requires few physical and economic resources to evaluate in short time (6 h) the cytotoxic effect of therapeutic products and additives to be included in shrimp culture•This inexpensive method requires only a modified Hank's balanced salt solution (HBSS) containing Ca2+ and Mg2+ to keep hemocytes metabolically active to successfully carry out the cytotoxicity assay•This toxicity in vitro assay does not require exposure of the shrimp to compounds at toxic concentrations.

Estrategias de tratamiento del paciente con hipertensión arterial esencial: Perfil neurohormonal y geometría ventricular izquierda

La geometría ventricular izquierda, determinada por ecocardiografía bidimensional, proporciona de manera indirecta información sobre el perfil hemodinámico y neurohormonal del paciente hipertenso. En dos estudios pilotos, llevados a cabo en el Instituto de Investigaciones Cardiovasculares de la Universidad de Los Andes hemos utilizado al patrón geométrico como guía para orientar el tratamiento farmacológico del paciente hipertenso. La correspondencia de la estrategia farmacológica con el mecanismo neurohormonal, responsable de la hipertensión arterial, permite un control de la presión arterial con menor número de medicamentos y reduce la incidencia de efectos colaterales y complicaciones. Más aún, el proceso de remodelación cardiaca puede ser influenciado favorable o desfavorablemente, si la estrategia terapéutica empleada se corresponde o no con el mecanismo neurohormonal subyacente. El proceso de remodelación cardiaca, en la transición hacia los dos fenotipos de insuficiencia cardiaca congestiva, se caracteriza por modificaciones opuestas de la geometría y función ventricular. Los pacientes que evolucionan hacia la insuficiencia cardiaca sistólica experimentan una progresiva dilatación de las cavidades cardiacas izquierdas y disminución de la función sistólica. Por el contrario, en los pacientes que evolucionan hacia la insuficiencia cardiaca diastólica, el tamaño de las cavidades cardiacas se reduce y la relajación ventricular se altera.

The neurohormonal and hemodynamic profiles, of uncomplicated hypertensive patients, can be inferred from the left ventricular geometric pattern. We have used the left ventricular geometric pattern to guide the pharmacological treatment of hypertensive patients. Blood pressure control can be achieved with less medications and complications and adverse effects are reduced with a therapeutic strategy aimed at the underlying neurohormonal and hemodynamic profiles. On the contrary, cardiac remodelling is unfavorably influenced by a therapeutic strategy unmatched to the underlying responsable mechanisms. During transition to the two phenotypes of congestive heart failure, cardiac remodelling evolves in opposite directions. Thus, patients with systolic heart failure undergo progressive ventricular dilatation with thinning of its walls, where as, diastolic heart failure patients are characterized by shrinking of their left ventricular cavities with increasing relative wall thickness.

Combined treatment of leachate from sanitary landfill and municipal wastewater by UASB reactors.

Landfills are among the most affordable and acceptable methods in terms of public health and environmental protection for the final disposal of solid waste. Leachate treatment incorporated into anaerobic domestic wastewater systems could be a viable and efficient alternative which would allow minimizing implementation and operation costs of the landfill, to reduce requirements of chemical inputs such as pH conditioners and phosphorus supply. This study showed the potential of anaerobic treatment in an UASB reactor treating a combination of domestic wastewater and leachate in a 5% volumetric ratio of leachate. Under these conditions the reactor assimilated properly the leachate fraction incorporated. With a HRT of 8 h and a mean volumetric organic load of 2.84 kg m(-3) d(-1) COD removal efficiencies around 70% were obtained, without inhibition problems; however, the necessity of a complementary treatment for improving carbonaceous and nitrogenous organic matter reduction is evident.