Inhibitory action of essential oils against proteases activity of Paenibacillus larvae, the etiological agent of American Foulbrood disease

American foulbrood (AFB) is a disease affecting the larva of Apis mellifera. The etiological agent is Paenibacillus larvae, which releases metalloproteases involved in the degradation of larval tissues. Through quorum sensing (QS) mechanism, bacteria are able to activate specific genes such as virulence factors. The exoproteases regulation of P. larvae could be associated with QS. A promising mechanism of AFB control is to block QS mechanism with essential oils (EO). The aim of this study was to investigate the potential presence of QS signals in the regulation of P. larvae proteases and the effect of seven EOs on the exoproteases activity of P. larvae. From growth curves and evaluation of the presence of proteases by milk agar plates assay, it was observed protease activity during the late exponential phase of growth. Early production of protease activity (15 hours earlier than control) was observed when a low density culture was incubated with late exponential spent medium (SM) suggesting the presence of factor(s) inducing this activity. SM was obtained by the ultrafiltration of P. larvae cultures on late growth phase and was free of proteases. Proteolytic activity was quantified on P. larvae cultures in presence of sublethal concentration of EO by azocasein method. The EOs, except S. chilensis EO, reduced significantly protease activity (more than 50%). We report for the first time evidence on the possible role of QS on P. larvae and the antiproteolytic activity of EOs (except for S. chilensis) on exoproteases, an interesting therapeutic strategy to control AFB

Revolution of the post-mineralization marianas hydrothermal eruption breccia, Cerro Negro district, Patagonia, Argentina

Fil: Permuy Vidal, Conrado. Instituto de Recursos Minerales (INREMI). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Zalazar, M.. Instituto de Recursos Minerales (INREMI). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Guido, Diego Martín. Instituto de Recursos Minerales (INREMI). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Brown, G.

Culicidae (Diptera) en un Área Rural del Chaco Seco, Argentina

Con el objetivo de estudiar algunos aspectos ecológicos de mosquitos en la región fitogeográfica del Chaco Seco, se realizó un estudio entre febrero y diciembre de 2007 en Misión Nueva Pompeya, Provincia del Chaco. Se seleccionaron tres parajes: "Fortín Arenales", "Los Pozos" y "Nueva Población". En cada paraje se seleccionaron tres estaciones de captura: extradomicilio (correspondiente a un bosque distante entre 90 y 110 m del domicilio), peridomicilio (representado por el corral distante hasta 10 m del domicilio) e intradomicilio (representado por las viviendas de los pobladores). Se determinaron 21 especies de mosquitos, correspondientes a 8 géneros. Se estimó el Índice de Abundancia de Especies (IAE) y la diversidad específica de cada uno de los parajes y de las estaciones de captura. Se realizó además un análisis de "clusters" para comparar los tres parajes y las tres estaciones de captura en cuanto a abundancia y diversidad de especies halladas. Las especies más abundantes fueron Mansonia titillans (Walker), Uranotaenia apicalis (Theobald) y Anopheles triannulatus (Neiva y Pinto). En cuanto a la estacionalidad, las capturas mensuales revelaron una estación con poca o casi nula presencia de mosquitos (estación seca) y un período con mayor abundancia, riqueza y diversidad de especies (estación lluviosa)

Diamond-Based Thin Film Bulk Acoustic Wave Resonator for Biomedical Applications

Nowadays it is in constant growing the development of thin film bulk acoustic resonators. If the piezoelectric material is going to be implanted in the human body, an important requirement is the biocompatibility of the implant. In this regard, Aluminum Nitride (AlN) has emerged as an attractive alternative for use in biomedical MicroElectroMechanical Systems. Ultrananocrystalline Diamond (UNCD) is a promising material to be used in biomedical applications, due to its extraordinary mulifunctionality; it is exceptional for implantable medical devices requiring stringent biological performance. Since both UNCD and AlN films can be processed via photolithography processes used in microfabrication, the integration of UNCD and AlN films provides the bases for developing a new generation of biocompatible Bio-MEMS/NEMS. Research and development was conducted to produce implantable MEMS devices: Pt/piezoelectric AlN/Pt layer heterostructure was grown and patterned on the UNCD membrane with a Ti adhesion layer. By applying voltages between the top and bottom Pt electrodes layers the piezoelectric AlN layer is energized. The feasibility of the fabrication of biocompatible AlN/diamond-based FBAR structure has been demonstrated.Fil: Zalazar, Martin. Universidad Nacional de Entre Rios. Facultad de Ingenieria. Departamento de Bioingenieria; ArgentinaFil: Guarnieri, Fabio Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico. Centro de Investigación de Métodos Computacionales; Argentina. Universidad Nacional de Entre Rios. Facultad de Ingenieria. Departamento de Bioingenieria; Argentin

Pelecitus tercostatus (Molin, 1960) (Nematoda, Onchocercidae) in Amazona vinacea (Aves, Psittaciformes) from Argentina: Morphological details and clinical findings

Pelecitus tercostatus (Molin, 1860) (Onchocercidae, Dirofilariinae) was found in the leg of a Vinaceous-breasted Parrot Amazona vinacea (Aves, Psittaciformes) from Misiones, Argentina. The present report enlarges the host distribution of the species and represents the first record of any nematode in A. vinacea. The macroscopic lesions produced in the bird are also described.Centro de Estudios Parasitológicos y de Vectore

Distribución de enfermedades transmitidas por chicharritas en cultivos de maíz en la campaña 2012/13

La continuidad geográfica de los cultivos y de los germoplasmas empleados en Argentina, favorecen la presencia y la incidencia de las enfermedades del maíz transmitidas por chicharritas. Durante la última década, en Argentina se ha ido produciendo la continuidad geográfica de los cultivos, desde el extremo norte del país hasta las puertas de la Patagonia, lo que plantea un contexto diferenteal existente previamenteen la epidemiología de las enfermedades que los afectan. El empleo de nuevas tecnologías y estrategias de manejo permitieron que la agricultura avanzara sobre tierras antes dedicadas a la ganadería, con pastizales o monte natural. Tal es el caso de una amplia franja del centro del país, que al carecer de cultivos se comportaba como barrera natural bloqueando el paso de inóculos desde una zona a otra. Esta franja se ha ido reduciendo e incluso ha desaparecido en algunas zonas.publishedVersionFil: Vicondo, Manuel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina.Fil: Druetta, Marcelo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina.Fil: Maurino, María Fernanda. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina.Fil: Raspanti, Jorge. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina.Fil: Virla, Eduardo G. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Planta Piloto de Procesos Industriales Microbiológicos (PROIMI); Argentina.Fil: Zalazar, N. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santiago del Estero; Argentina.Fil: Ruiz Posse, Eduardo Juan. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Laguna, Irma Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina.Fil: Giménez Pecci, María de la Paz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP). Instituto de Patología Vegetal (IPAVE); Argentina

Partial Deletion of Chromosome 8 β-defensin Cluster Confers Sperm Dysfunction and Infertility in Male Mice

β-defensin peptides are a family of antimicrobial peptides present at mucosal surfaces, with the main site of expression under normal conditions in the male reproductive tract. Although they kill microbes in vitro and interact with immune cells, the precise role of these genes in vivo remains uncertain. We show here that homozygous deletion of a cluster of nine β-defensin genes (DefbΔ9) in the mouse results in male sterility. The sperm derived from the mutants have reduced motility and increased fragility. Epididymal sperm isolated from the cauda should require capacitation to induce the acrosome reaction but sperm from the mutants demonstrate precocious capacitation and increased spontaneous acrosome reaction compared to wild-types but have reduced ability to bind the zona pellucida of oocytes. Ultrastructural examination reveals a defect in microtubule structure of the axoneme with increased disintegration in mutant derived sperm present in the epididymis cauda region, but not in caput region or testes. Consistent with premature acrosome reaction, sperm from mutant animals have significantly increased intracellular calcium content. Thus we demonstrate in vivo that β-defensins are essential for successful sperm maturation, and their disruption leads to alteration in intracellular calcium, inappropriate spontaneous acrosome reaction and profound male infertility

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.