Dynamic stability of long axisymmetric liquid bridges

This paper deals with the non-linear forced oscillations of axisymmetric long liquid bridges between equal disks. The dynamics of the liquid bridge has been analyzed by using a self-similar, one-dimensional model already used in similar problems. The influence of the dynamics on the static stability limits, as well as the main characteristics of the non-linear behaviour of long liquid bridges, have been studied with in the range of validity of the mathematical model used here

Fish granzymes and their role in the innate cell-mediated cytotoxicity against nodavirus-infected cells

Granzymes (Gzm) are granule-associated serine proteases, which are important effector molecules in cell-mediated cytotoxicity, classified by its proteolytic activity in: tryptase (GzmA and GzmK), Asp-ase (GzmB), Met-ase (GzmM) or chymase (others). In fish, even at gene level, very few studies have partially identified and characterize them. In this work we have identified the activity of these four granzymes, using colorimetric assays, in leucocytes from gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax), and how they are increased upon cytotoxic activity against nodavirus-infected tumor cells. The results also showed that GzmA was the most abundant and GzmB the lowest. Deeper characterization of the GzmB led us to identify that seabream leucocytes under cytotoxic response against nodavirus-infected cells showed significantly increased GzmB activity whilst this pattern failed to do so in sea bass leucocytes. Moreover, flow cytometry studies also suggested the presence of GzmB into the cytoplasm of effector cells. At gene level, seabream GzmB gene was found to be up-regulated in leucocytes under cytotoxic activity, mainly if the target cells were infected with nodavirus. These data will through some light in the importance of granzymes in the cytotoxic response of fish and their defense against nodavirus infection

Columnas líquidas en condiciones de ingravidez : informe final 1981

Columnas líquidas en condiciones de ingravidez : informe final 198

Characterization of the interferon pathway in the European sea bass after nodavirus infection

One of the most powerful innate immune responses against virus is mediated by type I interferon (IFN). We searched the presence of genes involved in the IFN pathway in European sea bass (Dicentrarchus labrax) and evaluated their regulation by nodavirus (VNNV) infection in brain and gonad of infected specimens as well as in a new sea bass cell line (DLB-1), derived from brain. We identified genes encoding MDA5 (Melanoma Differentiation Associated gene 5), LGP2 (Laboratory of Genetics and Physiology 2), MAVS (mitochondrial antiviral signaling protein), TRAF3 (tumour necrosis factor receptor-associated factor 3), TANK (TRAF family member-associated NF-kB activator), TBK1 (TANK binding kinase 1), IRF3 (IFN regulatory factor 3), IRF7 and PKR (dsRNA dependent protein kinase receptor). Thus, in the susceptible species European sea bass, we found that mda5, lgp2 or irf3 gene expression in brain was up-regulated by VNNV infection, as ifn, mx and pkrgenes at different sampling times. Strikingly, most of the genes were up-regulated in gonad. In DLB-1 cell line, most of them were up-regulated by VNNV infection but in lower level than the induction provoked by poly I:C treatment. Further studies will be conducted to characterize the IFN pathway in sea bass and their role in the immune response against VNNV

Vaccination with UV-inactivated nodavirus partly protects European sea bass against infection, while inducing few changes in immunity

Developing viral vaccines through the ultraviolet (UV) inactivation of virus is promising technique since it is straightforward and economically affordable, while the resulting viruses are capable of eliciting an adequate antiviral immune response. Nodavirus (NNV) is a devastating virus that mainly affects European sea bass juveniles and larvae, causing serious economic losses in Mediterranean aquaculture. In this work, a potential vaccine consisting on UV-inactivated NNV (iNNV) was generated and administered to healthy juveniles of European sea bass to elucidate whether it triggers the immune response and improves their survival upon challenge. First, iNNV failed to replicate in cell cultures and its intraperitoneal administration to sea bass juveniles also failed to produce fish mortality and induction of the type I interferon (IFN) pathway, indicating that the NNV was efficiently inactivated. By contrast, iNNV administration induced significant serum non-specific antimicrobial activity as well as a specific antiviral activity and immunoglobulin M (IgM) titres against NNV. Interestingly, few changes were observed at transcriptional level in genes related to either innate or adaptive immunity, suggesting that iNNV could be modulating the immune response at protein or functional level. In addition, the iNNV vaccinated group showed improved survival, reaching a relative survival percentage of 57.9%. Moreover, challenged fish that had been vaccinated presented increased serum antibacterial, antiviral and IgM titres, as well as the higher transcription of mhc1a, ifn, isg15 and cd8a genes in brain, while in the head-kidney the transcription of mhc1a, mhc2b and cd8a was down regulated and mx, isg15 and tcrb was up-regulated. Although the UV-inactivated vaccine against NNV showed promising results, more effort should be addressed to improving this prophylactic method by increasing our understanding of its action mechanisms, thus enabling the mortality rate of NNV to be further reduced.Postprint3,26