Broad Reactivity Single Domain Antibodies against Influenza Virus and Their Applications to Vaccine Potency Testing and Immunotherapy

The antigenic variability of influenza presents many challenges to the development of vaccines and immunotherapeutics. However, it is apparent that there are epitopes on the virus that have evolved to remain largely constant due to their functional importance. These more conserved regions are often hidden and difficult to access by the human immune system but recent efforts have shown that these may be the Achilles heel of the virus through development and delivery of appropriate biological drugs. Amongst these, single domain antibodies (sdAbs) are equipped to target these vulnerabilities of the influenza virus due to their preference for concave epitopes on protein surfaces, their small size, flexible reformatting and high stability. Single domain antibodies are well placed to provide a new generation of robust analytical reagents and therapeutics to support the constant efforts to keep influenza in check

Tranexamic Acid Modulates The Immune Response And Reduces Postsurgical Infection Rates

Tranexamic acid (TXA) is an antifibrinolytic agent that blocks plasmin formation. Because plasmin is known to promote inflammatory and immunosuppressive responses, we explored the possibility that plasmin-mediated immunosuppression in patients undergoing cardiac surgery can be directly reversed by TXA and decrease postoperative infection rates. The modulatory effect of TXA on inflammatory cytokine levels and on innate immune cell activation were evaluated with multiplex enzyme-linked immunosorbent assay and flow cytometry, respectively. Postoperative infection rates were determined in patients undergoing cardiac surgery and randomized to TXA (ACTRN12605000557639; http://www.anzca.edu.au). We demonstrate that TXA-mediated plasmin blockade modulates the immune system and reduces surgery-induced immunosuppression in patients following cardiac surgery. TXA enhanced the expression of immune-activating markers while reducing the expression of immunosuppressive markers on multiple myeloid and lymphoid cell populations in peripheral blood. TXA administration significantly reduced postoperative infection rates, despite the fact that patients were being administered prophylactic antibiotics. This effect was independent of the effect of TXA at reducing blood loss. TXA was also shown to exert an immune-modulatory effect in healthy volunteers, further supporting the fibrin-independent effect of TXA on immune function and indicating that baseline plasmin levels contribute to the regulation of the immune system in the absence of any comorbidity or surgical trauma. Finally, the capacity of TXA to reduce infection rates, modulate the innate immune cell profile, and generate an antifibrinolytic effect overall was markedly reduced in patients with diabetes, demonstrating for the first time that the diabetic condition renders patients partially refractory to TXA

Saturation mutagenesis of putative catalytic residues of benzoylformate decarboxylase provides a challenge to the accepted mechanism

Benzoylformate decarboxylase from Pseudomonas putida (PpBFDC) is a thiamin diphosphate-dependent enzyme that carries out the nonoxidative decarboxylation of aromatic 2-keto acids. The x-ray structure of PpBFDC suggested that Ser-26, His-70, and His-281 would play important roles in its catalytic mechanism, and the S26A, H70A, and H281A variants all exhibited greatly impaired catalytic activity. Based on stopped-flow studies with the alanine mutants, it was proposed that the histidine residues acted as acid-base catalysts, whereas Ser-26 was involved in substrate binding and played a significant, albeit less well defined, role in catalysis. While developing a saturation mutagenesis protocol to examine residues involved in PpBFDC substrate specificity, we tested the procedure on His-281. To our surprise, we found that His-281, which is thought to be necessary for protonation of the carbanion/enamine intermediate, could be replaced by phenyl alanine with only a 5-fold decrease in kcat. Even more surprising were our subsequent observations (i) that His-70 could be replaced by threonine or leucine with approximately a 30-fold decrease in kcat/Km compared with a 4,000-fold decrease for the H70A variant and (ii) that Ser-26, which forms hydrogen bonds with the substrate carboxylate, could be replaced by threonine, leucine, or methionine without significant loss of activity. These results call into question the assigned roles for Ser-26, His-70, and His-281. Further, they demonstrate the danger in assigning catalytic function based solely on results with alanine mutants and show that saturation mutagenesis is a valuable tool in assessing the role and relative importance of putative catalytic residues

Efecto antioxidante del extracto acuoso de Lepidium meyenii walpers (Maca) en animales de experimentación con osteoporosis inducida

We evaluate the maca antioxidant effect in albino rats to observe its influence in the development of osteoporosis. Twenty five (25) four month female albino rats were used and divided ¡nto five groups. Gl a control group and four sample groups (G2, G3, G4 and G5) were forced to have osteoporosis with heparina 2U / gl every other day for a thrce week period, at the same time they were given antioxidants (G3) and natural products (maca, G4 and soya, GS) where G2 the osteoporosis c( ntrol group. At the end of thi5 period blood and urine samples were taken for the analysis of catalase(CAT) and dismutase super oxide (SOD) to evaluate the antioxidant effect and Hidroxiprolina urine and calcium as indicators in the lose out of calcium (resorbtion osea). The G2 which presented osteoporosis showed an increase in their antioxidants enzymes while maca was the natural product which presented reasonable results in comparison with the one obtained in group G3 which were given vitamin CE and selenite and the group GS which were given soya. Therefore we could observe the favorable maca consumption against the osteoporosis evolution. In conclusion maca could be used as an alternative and in the prevention and treatment of this illness.Se evaluó el efecto antioxidante de Lepidium meyenii walpers (Maca) en ratas albinas para observar su influencia sobre el desarrollo de la osteoporosis. Se utilizaron 25 ratas hembras albinas de 4 meses de edad, las que fueron divididas en 5 grupos, el primer grupo (Gl) considerado como control y 4 grupos experimentales (G2, G3, G4 Y GS) se les indujo osteoporosis aplicándose1es heparina 2Ulj g/ interdiariamente por un periodo de tres semanas, al mismo tiempo se efectuó la administración de antioxidantes (G3) y productos naturales (maca al G4 y soya al GS) siendo G2 el grupo control de osteoporosis. Al término de este periodo se tomó muestras de sangre y orina para los análisis de Cata lasa (CA T) Y Superóxido Dismutasa (SOD) para evaluar el efecto antioxidante e Hidroxiprolina urinaria y calcio como marcadores de la resorción ósea. El grupo G2 que presentó osteoporosis mostró una elevación de sus enzimas antioxidantes mientras que la maca fue el producto natural que presento resultados considerables en comparación con el grupo G3 al que se administró vitaminas e, E y selenito y el grupo GS al que se administró soya. Por lo tanto se evidencia una influencia favorable del consumo de maca contra el progreso de la osteoporosis. En conclusión la maca puede ser utilizada como alternativa en la prevención y tratamiento de esta enfermedad