Physicochemical characterization and antimicrobial activity of mucus of Achatina fulica

Introducción: El caracol gigante africano Achatina fulica es reconocido como una plaga que afectala biodiversidad, la Salud Pública y la productividad. Sin embargo, se ha demostrado que su secreción mucosa tiene propiedades cosméticas, cicatrizantes y antimicrobianas. Objetivo: Determinar las características físico-químicas y evaluar la actividad antimicrobiana de la secreción mucosa de Achatina fulica. Metodología: Se hicieron pruebas bioquímicas para la determinación cualitativa y cuantitativa de glúcidos, proteínas y lípidos. Se determinó el contenido de Calcio, Potasio, cloruros, Sodio y Magnesio. Se midieron los parámetros de conductividad eléctrica, potencial óxido-reducción, saturación de oxígeno, oxígeno total disuelto, pH, sólidos disueltos totales. Se realizó un ensayo de actividad antibacteriana por la técnica de microdilución en caldo. Resultados: Se encontraron glúcidos en concentraciones de 582 μg/mL en la fracción soluble y de 62.1 μg/mL en la fracción de mucinas, y proteínas en concentraciones de 836 μg/mL en la fracción soluble y de 1413 μg/mL en la fracción de mucinas. Se observó actividad antimicrobiana frente a las tres cepas ensayadas. Streptococcus agalactiae alcanzó un MIC90 a una concentración de 3,6 mg/mL con la fracción de mucinas; Staphylococcus aureus resistente a meticilina tuvo un MIC50 de 3,3 mg/mL y Escherichia coli un MIC 70 de 3.8 mg/mL. Conclusiones: Se reportan por primera vez las características físicas y los oligoelementos presente en la secreción de Achatina fulica. La actividad antibacteriana obtenida frente a cepas Gram positivas y Gram negativas plantea la necesidad de realizar estudios para purificar las moléculas con dicha actividad, conocer los mecanismos de acción y establecer la inocuidad, entre otros.Introduction: The giant African snail Achatina fulica is recognized as a scourge affecting biodiversity,public health and productivity. However, it has been shown that the mucus has cosmetic, healing and antimicrobial properties. Objective: Determine physico-chemical characteristics and evaluate the antimicrobial activity of the mucus. Methodology: Qualitative and quantitative determinations of carbohydrates, proteins and lipids were made by biochemical tests. Using multiparameter meter parameters of electrical conductivity, redox potential, oxygen saturation, the total dissolved oxygen, pH, total dissolved solids were measured. Content of Calcium, Potassium, chloride, Sodium and Magnesium was determined. Antibacterial activity assay was performed by broth microdilution method against Gram positive and Gram negative bacteria. Results: Carbohydrates were found in concentrations of 582 μg/mL in soluble fraction and 62.1 μg/mL in mucin fraction, and protein concentration of 836 μg/mL in the soluble fraction and 1413 μg/mL in mucin fraction. Antimicrobial activity was demonstrated against the three strains tested. Streptococcus agalactiae reached MIC90 at a concentration of 3.6 μg/mL with mucin fraction; Methicillin-Resistant Staphylococcus aureus had a MIC50 of 3.3 mg / mL and Escherichia coli had a MIC70 of 3.8 mg / mL. Conclusions: This is the first report of the physical and trace elements in the secretion of Achatina fulica. The antibacterial activity obtained against Gram positive and Gram negative strains raises the need for studies to purify the molecules with such activity, understanding the mechanisms of action and establish the safety, among others

Physicochemical characterization and antimicrobial activity of mucus of Achatina fulica

Introducción: El caracol gigante africano Achatina fulica es reconocido como una plaga que afectala biodiversidad, la Salud Pública y la productividad. Sin embargo, se ha demostrado que su secreción mucosa tiene propiedades cosméticas, cicatrizantes y antimicrobianas. Objetivo: Determinar las características físico-químicas y evaluar la actividad antimicrobiana de la secreción mucosa de Achatina fulica. Metodología: Se hicieron pruebas bioquímicas para la determinación cualitativa y cuantitativa de glúcidos, proteínas y lípidos. Se determinó el contenido de Calcio, Potasio, cloruros, Sodio y Magnesio. Se midieron los parámetros de conductividad eléctrica, potencial óxido-reducción, saturación de oxígeno, oxígeno total disuelto, pH, sólidos disueltos totales. Se realizó un ensayo de actividad antibacteriana por la técnica de microdilución en caldo. Resultados: Se encontraron glúcidos en concentraciones de 582 μg/mL en la fracción soluble y de 62.1 μg/mL en la fracción de mucinas, y proteínas en concentraciones de 836 μg/mL en la fracción soluble y de 1413 μg/mL en la fracción de mucinas. Se observó actividad antimicrobiana frente a las tres cepas ensayadas. Streptococcus agalactiae alcanzó un MIC90 a una concentración de 3,6 mg/mL con la fracción de mucinas; Staphylococcus aureus resistente a meticilina tuvo un MIC50 de 3,3 mg/mL y Escherichia coli un MIC 70 de 3.8 mg/mL. Conclusiones: Se reportan por primera vez las características físicas y los oligoelementos presente en la secreción de Achatina fulica. La actividad antibacteriana obtenida frente a cepas Gram positivas y Gram negativas plantea la necesidad de realizar estudios para purificar las moléculas con dicha actividad, conocer los mecanismos de acción y establecer la inocuidad, entre otros.Introduction: The giant African snail Achatina fulica is recognized as a scourge affecting biodiversity,public health and productivity. However, it has been shown that the mucus has cosmetic, healing and antimicrobial properties. Objective: Determine physico-chemical characteristics and evaluate the antimicrobial activity of the mucus. Methodology: Qualitative and quantitative determinations of carbohydrates, proteins and lipids were made by biochemical tests. Using multiparameter meter parameters of electrical conductivity, redox potential, oxygen saturation, the total dissolved oxygen, pH, total dissolved solids were measured. Content of Calcium, Potassium, chloride, Sodium and Magnesium was determined. Antibacterial activity assay was performed by broth microdilution method against Gram positive and Gram negative bacteria. Results: Carbohydrates were found in concentrations of 582 μg/mL in soluble fraction and 62.1 μg/mL in mucin fraction, and protein concentration of 836 μg/mL in the soluble fraction and 1413 μg/mL in mucin fraction. Antimicrobial activity was demonstrated against the three strains tested. Streptococcus agalactiae reached MIC90 at a concentration of 3.6 μg/mL with mucin fraction; Methicillin-Resistant Staphylococcus aureus had a MIC50 of 3.3 mg / mL and Escherichia coli had a MIC70 of 3.8 mg / mL. Conclusions: This is the first report of the physical and trace elements in the secretion of Achatina fulica. The antibacterial activity obtained against Gram positive and Gram negative strains raises the need for studies to purify the molecules with such activity, understanding the mechanisms of action and establish the safety, among others

Monozygotic twins concordant for common variable immunodeficiency : strikingly similar clinical and immune profile associated with a polygenic burden

Copyright © 2019 Silva, Fonseca, Pereira, Silva, Barbosa, Serra-Caetano, Blanco, Rosmaninho, Pérez-Andrés, Sousa, Raposo, Gama-Carvalho, Victorino, Hammarstrom and Sousa. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Monozygotic twins provide a unique opportunity to better understand complex genetic diseases and the relative contribution of heritable factors in shaping the immune system throughout life. Common Variable Immunodeficiency Disorders (CVID) are primary antibody defects displaying wide phenotypic and genetic heterogeneity, with monogenic transmission accounting for only a minority of the cases. Here, we report a pair of monozygotic twins concordant for CVID without a family history of primary immunodeficiency. They featured a remarkably similar profile of clinical manifestations and immunological alterations at diagnosis (established at age 37) and along the subsequent 15 years of follow-up. Interestingly, whole-exome sequencing failed to identify a monogenic cause for CVID, but unraveled a combination of heterozygous variants, with a predicted deleterious impact. These variants were found in genes involved in relevant immunological pathways, such as JUN, PTPRC, TLR1, ICAM1, and JAK3. The potential for combinatorial effects translating into the observed disease phenotype is inferred from their roles in immune pathways, namely in T and B cell activation. The combination of these genetic variants is also likely to impose a significant constraint on environmental influences, resulting in a similar immunological phenotype in both twins, despite exposure to different living conditions. Overall, these cases stress the importance of integrating NGS data with clinical and immunological phenotypes at the single-cell level, as provided by multi-dimensional flow-cytometry, in order to understand the complex genetic landscape underlying the vast majority of patients with CVID, as well as those with other immunodeficiencies.This work received funding from PAC - PRECISE - LISBOA-01-0145-FEDER-016394, co-funded by FEDER through POR Lisboa 2020 - Programa Operacional Regional de Lisboa PORTUGAL 2020 and Fundação para a Ciência e a Tecnologia; and UID/BIM/50005/2019, project funded by Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado. Work in MG-C lab is supported by UID/MULTI/04046/2019 Research Unit grant from FCT, Portugal (to BioISI) and FCT research grant PTDC/BIA-CEL/29257/2017.info:eu-repo/semantics/publishedVersio

Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form

Computational Approaches to Explainable Artificial Intelligence:Advances in Theory, Applications and Trends

Deep Learning (DL), a groundbreaking branch of Machine Learning (ML), has emerged as a driving force in both theoretical and applied Artificial Intelligence (AI). DL algorithms, rooted in complex and non-linear artificial neural systems, excel at extracting high-level features from data. DL has demonstrated human-level performance in real-world tasks, including clinical diagnostics, and has unlocked solutions to previously intractable problems in virtual agent design, robotics, genomics, neuroimaging, computer vision, and industrial automation. In this paper, the most relevant advances from the last few years in Artificial Intelligence (AI) and several applications to neuroscience, neuroimaging, computer vision, and robotics are presented, reviewed and discussed. In this way, we summarize the state-of-the-art in AI methods, models and applications within a collection of works presented at the 9 International Conference on the Interplay between Natural and Artificial Computation (IWINAC). The works presented in this paper are excellent examples of new scientific discoveries made in laboratories that have successfully transitioned to real-life applications

Transcription-replication conflicts: How they occur and how they are resolved

The frequent occurrence of transcription and DNA replication in cells results in many encounters, and thus conflicts, between the transcription and replication machineries. These conflicts constitute a major intrinsic source of genome instability, which is a hallmark of cancer cells. How the replication machinery progresses along a DNA molecule occupied by an RNA polymerase is an old question. Here we review recent data on the biological relevance of transcription-replication conflicts, and the factors and mechanisms that are involved in either preventing or resolving them, mainly in eukaryotes. On the basis of these data, we provide our current view of how transcription can generate obstacles to replication, including torsional stress and non-B DNA structures, and of the different cellular processes that have evolved to solve them

Virgo Detector Characterization and Data Quality during the O3 run

The Advanced Virgo detector has contributed with its data to the rapid growth of the number of detected gravitational-wave signals in the past few years, alongside the two LIGO instruments. First, during the last month of the Observation Run 2 (O2) in August 2017 (with, most notably, the compact binary mergers GW170814 and GW170817) and then during the full Observation Run 3 (O3): an 11 months data taking period, between April 2019 and March 2020, that led to the addition of about 80 events to the catalog of transient gravitational-wave sources maintained by LIGO, Virgo and KAGRA. These discoveries and the manifold exploitation of the detected waveforms require an accurate characterization of the quality of the data, such as continuous study and monitoring of the detector noise. These activities, collectively named {\em detector characterization} or {\em DetChar}, span the whole workflow of the Virgo data, from the instrument front-end to the final analysis. They are described in details in the following article, with a focus on the associated tools, the results achieved by the Virgo DetChar group during the O3 run and the main prospects for future data-taking periods with an improved detector.Comment: 86 pages, 33 figures. This paper has been divided into two articles which supercede it and have been posted to arXiv on October 2022. Please use these new preprints as references: arXiv:2210.15634 (tools and methods) and arXiv:2210.15633 (results from the O3 run

Virgo Detector Characterization and Data Quality: results from the O3 run

The Advanced Virgo detector has contributed with its data to the rapid growth of the number of detected gravitational-wave (GW) signals in the past few years, alongside the two Advanced LIGO instruments. First during the last month of the Observation Run 2 (O2) in August 2017 (with, most notably, the compact binary mergers GW170814 and GW170817), and then during the full Observation Run 3 (O3): an 11-months data taking period, between April 2019 and March 2020, that led to the addition of about 80 events to the catalog of transient GW sources maintained by LIGO, Virgo and now KAGRA. These discoveries and the manifold exploitation of the detected waveforms require an accurate characterization of the quality of the data, such as continuous study and monitoring of the detector noise sources. These activities, collectively named {\em detector characterization and data quality} or {\em DetChar}, span the whole workflow of the Virgo data, from the instrument front-end hardware to the final analyses. They are described in details in the following article, with a focus on the results achieved by the Virgo DetChar group during the O3 run. Concurrently, a companion article describes the tools that have been used by the Virgo DetChar group to perform this work.Comment: 57 pages, 18 figures. To be submitted to Class. and Quantum Grav. This is the "Results" part of preprint arXiv:2205.01555 [gr-qc] which has been split into two companion articles: one about the tools and methods, the other about the analyses of the O3 Virgo dat

Virgo Detector Characterization and Data Quality: tools

Detector characterization and data quality studies -- collectively referred to as {\em DetChar} activities in this article -- are paramount to the scientific exploitation of the joint dataset collected by the LIGO-Virgo-KAGRA global network of ground-based gravitational-wave (GW) detectors. They take place during each phase of the operation of the instruments (upgrade, tuning and optimization, data taking), are required at all steps of the dataflow (from data acquisition to the final list of GW events) and operate at various latencies (from near real-time to vet the public alerts to offline analyses). This work requires a wide set of tools which have been developed over the years to fulfill the requirements of the various DetChar studies: data access and bookkeeping; global monitoring of the instruments and of the different steps of the data processing; studies of the global properties of the noise at the detector outputs; identification and follow-up of noise peculiar features (whether they be transient or continuously present in the data); quick processing of the public alerts. The present article reviews all the tools used by the Virgo DetChar group during the third LIGO-Virgo Observation Run (O3, from April 2019 to March 2020), mainly to analyse the Virgo data acquired at EGO. Concurrently, a companion article focuses on the results achieved by the DetChar group during the O3 run using these tools.Comment: 44 pages, 16 figures. To be submitted to Class. and Quantum Grav. This is the "Tools" part of preprint arXiv:2205.01555 [gr-qc] which has been split into two companion articles: one about the tools and methods, the other about the analyses of the O3 Virgo dat

Search for narrow resonances in dilepton mass spectra in proton-proton collisions at root s=13 TeV and combination with 8 TeV data

Peer reviewe