89 research outputs found

    Repertoire Of Balb/c Mice Natural Anti-carbohydrate Antibodies: Mice Vs. Humans Difference, And Otherness Of Individual Animals

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    One of the most common genetic backgrounds for mice used as a model to investigate human diseases is the inbred BALB/c strain. This work is aimed to characterize the pattern of natural anti-carbohydrate antibodies present in the serum of 20 BALB/c mice by printed glycan array technology and to compare their binding specificities with that of human natural anti-carbohydrate antibodies. Natural antibodies (NAbs) from the serum of BALB/c mice interacted with 71 glycans from a library of 419 different carbohydrate structures. However, only seven of these glycans were recognized by the serum of all the animals studied, and other five glycans by at least 80% of mice. The pattern of the 12 glycans mostly recognized by the circulating antibodies of BALB/c mice differed significantly from that observed with natural anti-carbohydrate antibodies in humans. This lack of identical repertoires of natural anti-carbohydrate antibodies between individual inbred mice, and between mice and humans, should be taken into consideration when mouse models are intended to be used for investigation of NAbs in biomedical research

    Specific and reversible immobilization of proteins tagged to the affinity polypeptide C-LytA on functionalized graphite electrodes

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    We have developed a general method for the specific and reversible immobilization of proteins fused to the choline-binding module C-LytA on functionalized graphite electrodes. Graphite electrode surfaces were modified by diazonium chemistry to introduce carboxylic groups that were subsequently used to anchor mixed self-assembled monolayers consisting of N,N-diethylethylenediamine groups, acting as choline analogs, and ethanolamine groups as spacers. The ability of the prepared electrodes to specifically bind C-LytA-tagged recombinant proteins was tested with a C-LytA-ÎČ-galactosidase fusion protein. The binding, activity and stability of the immobilized protein was evaluated by electrochemically monitoring the formation of an electroactive product in the enzymatic hydrolysis of the synthetic substrate 4-aminophenyl ÎČ-D-galactopyranoside. The hybrid protein was immobilized in an specific and reversible way, while retaining the catalytic activity. Moreover, these functionalized electrodes were shown to be highly stable and reusable. The method developed here can be envisaged as a general, immobilization procedure on the protein biosensor field.This work was supported by grants BFU2010–17824, CTQ2008-04492-E and CTQ2010-18570 (Spanish Ministerio de Economia y Competitividad) and FPA-2010-055 (Valentian Government, Spain)

    Poly-3-Hydroxybutyrate Functionalization with BioF-Tagged Recombinant Proteins

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    Polyhydroxyalkanoates (PHAs) are biodegradable polyesters that accumulate in the cytoplasm of certain bacteria. One promising biotechnological application utilizes these biopolymers as supports for protein immobilization. Here, the PHA-binding domain of the Pseudomonas putida KT2440 PhaF phasin (BioF polypeptide) was investigated as an affinity tag for the in vitro functionalization of poly-3-hydroxybutyrate (PHB) particles with recombinant proteins, namely, full-length PhaF and two fusion proteins tagged to BioF (BioF-C-LytA and BioF-beta-galactosidase, containing the choline-binding module C-LytA and the beta-galactosidase enzyme, respectively). The protein-biopolyester interaction was strong and stable at a wide range of pHs and temperatures, and the bound protein was highly protected from self-degradation, while the binding strength could be modulated by coating with amphiphilic compounds. Finally, BioF-beta-galactosidase displayed very stable enzymatic activity after several continuous activity-plus-washing cycles when immobilized in a minibioreactor. Our results demonstrate the potentialities of PHA and the BioF tag for the construction of novel bioactive materials. IMPORTANCE Our results confirm the biotechnological potential of the BioF affinity tag as a versatile tool for functionalizing PHA supports with recombinant proteins, leading to novel bioactive materials. The wide substrate range of the BioF tag presumably enables protein immobilization in vitro of virtually all natural PHAs as well as blends, copolymers, or artificial chemically modified derivatives with novel physicochemical properties. Moreover, the strength of protein adsorption may be easily modulated by varying the coating of the support, providing new perspectives for the engineering of bioactive materials that require a tight control of protein loading

    Poly-L-Lysine-Based αGal-Glycoconjugates for Treating Anti-αGal IgE-Mediated Diseases

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    Mice; ImmunotherapyRatones; InmunoterapiaRatolins; ImmunoterĂ piaAnti-αGal IgE antibodies mediate a spreading allergic condition known as αGal-syndrome (AGS). People exposed to hard tick bites are sensitized to αGal, producing elevated levels of anti-αGal IgE, which are responsible for AGS. This work presents an immunotherapy based on polymeric αGal-glycoconjugates for potentially treating allergic disorders by selectively inhibiting anti-αGal IgE antibodies. We synthesized a set of αGal-glycoconjugates, based on poly-L-lysine of different degrees of polymerization (DP1000, DP600, and DP100), to specifically inhibit in vitro the anti-αGal IgE antibodies in the serum of αGal-sensitized patients (n=13). Moreover, an animal model for αGal sensitization in GalT-KO mice was developed by intradermal administration of hard tick’ salivary gland extract, mimicking the sensitization mechanism postulated in humans. The in vitro exposure to all polymeric glycoconjugates (5-10-20-50-100 ”g/mL) mainly inhibited anti-αGal IgE and IgM isotypes, with a lower inhibition effect on the IgA and IgG, respectively. We demonstrated a differential anti-αGal isotype inhibition as a function of the length of the poly-L-lysine and the number of αGal residues exposed in the glycoconjugates. These results defined a minimum of 27 αGal residues to inhibit most of the induced anti-αGal IgE in vitro. Furthermore, the αGal-glycoconjugate DP1000-RA0118 (10 mg/kg sc.) showed a high capacity to remove the anti-αGal IgE antibodies (≄75% on average) induced in GalT-KO mice, together with similar inhibition for circulating anti-αGal IgG and IgM. Our study suggests the potential clinical use of poly-L-lysine-based αGal-glycoconjugates for treating allergic disorders mediated by anti-αGal IgE antibodies

    An enzymatic system for decolorization of wastewater dyes using immobilized CueO laccase-like multicopper oxidase on poly-3-hydroxybutyrate

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    The presence of synthetic dyes in wastewaters generated by the textile industry constitutes a serious environmental and health problem that urges the scientific community on an appropriate action. As a proof-of-concept, we have developed a novel approach to design enzymatic bioreactors with the ability to decolorize dye solutions through the immobilization of the bacterial CueO laccase-like multicopper oxidase from Escherichia coli on polyhydroxybutyrate (PHB) beads by making use of the BioF affinity tag. The decolorization efficiency of the system was characterized by a series of parameters, namely maximum enzyme adsorption capacity, pH profile, kinetic constants, substrate range, temperature and bioreactor recycling. Depending on the tested dye, immobilization increased the catalytic activity of CueO by up to 40-fold with respect to the soluble enzyme, reaching decolorization efficiencies of 45-90%. Our results indicate that oxidase bioreactors based on polyhydroxyalkanoates are a promising alternative for the treatment of coloured industrial wastewaters

    Removal of natural anti-αGal antibodies elicits protective immunity against Gram-negative bacterial infections

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    Antibody-dependent enhancement (ADE) of bacterial infections occurs when blocking or inhibitory antibodies facilitate the infectivity of pathogens. In humans, antibodies involved in ADE of bacterial infections may include those naturally produced against Galα1-3GalÎČ1-4GlcNAcÎČ (αGal). Here, we investigate whether eliminating circulating anti-αGal antibodies using a soluble αGal glycopolymer confers protection against Gram-negative bacterial infections. We demonstrated that the in vivo intra-corporeal removal of anti-αGal antibodies in α1,3-galactosyltransferase knockout (GalT-KO) mice was associated with protection against mortality from Gram-negative sepsis after cecal ligation and puncture (CLP). The improved survival of GalT-KO mice was associated with an increased killing capacity of serum against Escherichia coli isolated after CLP and reduced binding of IgG1 and IgG3 to the bacteria. Additionally, inhibition of anti-αGal antibodies from human serum in vitro increases the bactericidal killing of E. coli O86:B7 and multidrug-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa. In the case of E. coli O86:B7, there was also an improvement in bacteria opsonophagocytosis by macrophages. Both lytic mechanisms were related to a decreased binding of IgG2 to the bacteria. Our results show that protective immunity against Gram-negative bacterial pathogens can be elicited, and infectious diseases caused by these bacteria can be prevented by removing natural anti-αGal antibodies

    Prevalence and prognosis of anxiety, insomnia, and type D personality in patients with myocardial infarction: A Spanish cohort

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    Background: It has been suggested that patients with myocardial infarction and non-obstructive coronary arteries (MINOCA) have more psycho-emotional disorders than patients with obstructive coronary artery disease (MICAD). The aim of this study is to compare the prevalence of anxiety, insomnia, and type D personality between MINOCA and MICAD and their impact on prognosis. Methods: Patients with myocardial infarction undergoing coronary angiography were prospectively enrolled. Psychological questionnaires were completed by each patient during admission. Results: Among a total of 533 patients, 56 had MINOCA and 477 had MICAD. There were no differences in the prevalence of anxiety and insomnia between both groups: trait anxiety median value (M) MINOCA = 18 (11–34) vs. MICAD M = 19 (12–27), p = 0.8; state anxiety MINOCA M = 19 (11–29) vs. MICAD M = 19 (12.2–26), p = 0.6; and insomnia MINOCA M = 7 (3–11) vs. MICAD M = 7 (3–12), p = 0.95. More MINOCA patients had type D personality (45.0% vs. 28.5%, p = 0.03). At 3-year follow-up, there were no differences in mortality between MINOCA and MICAD (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.28–2.17) in major adverse cerebral or cardiovascular events (MACCE) (HR 0.71, 95% CI 0.38–1.31). Scores of trait anxiety and negative affectivity were significantly associated with MACCE (HR 1.65, 95% CI [1.05–2.57]; HR 1.75, 95% CI [1.11–2.77], respectively). High insomnia levels were associated with greater mortality (HR 2.72, 95% CI [1.12–6.61]). Conclusions: Anxiety and insomnia levels were similar between patients with MINOCA and those with MICAD, whilst the prevalence of type D personality was higher in the MINOCA than in the MICAD group. Higher scores in trait anxiety, insomnia, and negative affectivity were related to a worse prognosis at 3-year follow-up

    Naturalization of the microbiota developmental trajectory of Cesarean-born neonates after vaginal seeding

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    Early microbiota perturbations are associated with disorders that involve immunological underpinnings. Cesarean section (CS)-born babies show altered microbiota development in relation to babies born vaginally. Here we present the first statistically powered longitudinal study to determine the effect of restoring exposure to maternal vaginal fluids after CS birth.This work was partially supported by the C&D Research Fund, the Emch Fund for Human Microbiome Studies, and CIFAR FS20-078 #125869 (to M.G.D.-B.); Chilean CONICYT PIA/ANILLO grant ACT172097 and Chilean SOCHIPE Project 022019 (to P.R.H.); and the Norwegian Institute of Public Health (2019-0350), the Emerald Foundation, an NIH Pioneer award (1DP1AT010885), the National Institute of Justice (2016-DN-BX-4194), the San Diego Digestive Diseases Research Center (NIDDK 1P30DK120515), Janssen Pharmaceuticals (20175015)Peer reviewe

    The Youngest Victims: Children and Youth Affected by War

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    In 1989, the United Nation Convention on the Rights of the Child declared, “[state parties] shall take all feasible measures to ensure protection and care of children who are affected by an armed conflict.” In addition to attempting to secure the welfare of children in armed conflict, the Convention went on to ban the recruitment and deployment of children during armed conflict. Despite the vast majority of sovereign nations signing and ratifying this agreement, this treaty, unfortunately, has not prevented children and youth from witnessing, becoming victims of, or participating in political, ethnic, religious, and cultural violence across the past three decades. This chapter offers an “ecological perspective” on the psychosocial consequences of exposure to the trauma of war-related violence and social disruption

    Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

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    Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial
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