Discovery of a low-mass companion embedded in the disk of the young massive star MWC 297 with VLT/SPHERE

We report the discovery of a low-mass stellar companion around the young Herbig Be star MWC 297. We performed multi-epoch high-contrast imaging in the near infrared (NIR) with the Very Large Telescope (VLT)/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. The companion is found at projected separation of 244.7$\pm$13.2 au and a position angle of 176.4$\pm$0.1 deg. The large separation supports formation via gravitational instability. From the spectrum, we estimate a mass of 0.1-0.5 M$_{\odot}$, the range conveying uncertainties in the extinction of the companion and in evolutionary models at young ages. The orbit coincides with a gap in the dust disk inferred from the Spectral Energy Distribution (SED). The young age ($\lesssim$ 1 Myr) and mass ratio with the central star ($\sim 0.01$) makes the companion comparable to PDS 70~b, suggesting a relation between formation scenarios and disk dynamics.Comment: 4 figure

NL mind-best: aweb server for ligands and proteins discovery; theoretic experimental study of proteins of giardia lamblia

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Quantification of low levels of rainbow trout immunoglobulin by enzyme immunoassay using two monoclonal antibodies

An enzyme immunoassay has been developed for quantitation of low levels of trout immunoglobulin (Ig). This assay uses two monoclonal antibodies, one as capture antibody and the other as detector, directed against two non-overlapping epitopes on the heavy chains of trout Ig. The assay shows high reproducibility and can detect 0.12 μg trout Ig ml-1. Coefficients of intra- and interassay variation ranged from 3.8 to 7.1% and from 7.9 to 17.4%, respectively. Analysis of 37 healthy trout showed increasing serum Ig concentration with size. The mean Ig concentration was 0.67 mg ml-1 for trout of about 20 g and 9.1 mg ml-1 for trout weighing more than 125 g. © 1993

Monoclonal antibodies to turbot (Scophthalmus maximus) immunoglobulins characterization and applicability in immunoassays

Five monoclonal antibodies (mAbs) to immunoglobulins (Igs) of the turbot Scophthalmus maximus were produced and characterized. All the mAbs (denominated UR1, UR3, UR4, UR6 and UR7) are of isotype IgG1/κ and show good anti-turbot Ig reactivity in enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Results of competitive ELISA and immunoblotting analysis indicate that these five mAbs react with at least three different epitopes on the turbot Ig H chain. Except in the case of UR1, reactivity with periodate-treated purified turbot Ig was much lower than with the untreated Ig, suggesting that carbohydrate residues are involved in epitope recognition. All the mAbs showed reactivity with sera from the closely related species Scophthalmus rhombus but not with sera from species of other flatfish genera. One of these mAbs (UR3) has been successfully applied for the detection of antibodies against Vibrio anguillarum in ELISA. © 1994

Effect of clofibrate on the growth-kinetics of the murine P 1798(sc) lymphoma

Summary Clofibrate (CPIB) is a drug applied as an antilipidaemic agent in mammals. In this work we have tested its efficacy in vivo on the growth kinetics of P 1798(sc) lymphoma transplanted to recipient (BALB/c x AKR)F1 mice. Our results show a facilitation of the tumour growth rate in treated recipients. This fact may be related to an effect of the agent on the recipient which produces a decrease in the immune response as was confirmed on testing CPIB on thymus-dependent antigens in haemolytic plaque assays. Immune responses to experimental tumours can either facilitate their growth or cause their eradication from the host. Furthermore, several reports have indicated that the resistance of tumour cells to humoral immune attack is directly correlated with their ability to synthesize complex lipids as measured by the incorporation of fatty acids into extractable lipid macromolecules (Schlager & Ohanian, 1977). Some of these cells can be rendered susceptible to immune attack by treatment with certain metabolic inhibitors and chemotherapeutic drugs used in cancer treatment

Protein-A binding characteristics of rainbow trout (Oncorhynchus mykiss) immunoglobulins

1. 1. A small proportion (<0.5%) of rainbow trout immunoglobulins (Igs) binds to MemSep® staphylococcal protein-A (SpA) cartridges. SDS-PAGE analysis of this fraction under reducing conditions, and immunoblotting analysis with anti-heavy (H)-chain and anti-light (L)-chain monoclonal antibodies (mAbs), showed that, in addition to the characteristic H and L chains of rainbow trout Ig, two other peptides were also retained. 2. 2. The first peptide (P1) has a Mr of 65,000 and is recognized by rainbow trout anti-H-chain mAbs; the second (P2) has a Mr of 24,000. Fast protein liquid chromatography (FPLC) and SDS-PAGE analysis showed that the P1/P2 complex has a Mr of about 465,000, and that the P2 peptide (a) lacks disulphide bonds, (b) is present in molar excess with respect to P1 and (c) does not react with rainbow trout anti-L-chain mAbs. 3. 3. These results indicate that the P1/P2 complex is not an Ig variant. 4. 4. The presence of these peptides should be taken into account when analysing the molecular basis of the interaction of nonmammalian Igs with SpA, or when using SpA coupled to solid supports to purify fish Igs with a low SpA binding ratio. © 1993