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1.
Arch Virol ; 169(5): 107, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38647708

RESUMEN

African swine fever (ASF) is a highly fatal and contagious viral disease caused by African swine fever virus (ASFV). It has caused significant economic losses to the swine industry and poses a serious threat to food security worldwide. Diagnostic tests with high sensitivity are essential for the effective management of ASF. Here, we describe a single-tube nested PCR (STN-PCR) assay for the detection of ASFV in which two consecutive amplification steps are carried out within a single tube. Two pairs of primers (outer and inner) were designed to target the p72 gene of ASFV. The primer concentrations, annealing temperatures, and number of amplification cycles were optimized to ensure the consecutive utilization of outer and inner primer pairs during amplification while minimizing the likelihood of amplicon contamination. In comparison with two conventional endpoint PCR assays (one of which is recommended by the World Organization for Animal Health), the newly developed STN-PCR assay demonstrated a 100-fold improvement in the limit of detection (LOD), detecting 100 copies of ASFV genomic DNA, whereas the endpoint PCR assays could detect no fewer than 10,000 copies. The clinical performance of the STN-PCR assay was validated using 95 tissue samples suspected of being positive for ASFV, and the assay showed 100% specificity. A Cohen's kappa value of 0.91 indicated perfect agreement between the assays. This new STN-PCR assay is a potentially valuable tool that will facilitate the control of ASF.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Virus de la Fiebre Porcina Africana/genética , Virus de la Fiebre Porcina Africana/aislamiento & purificación , Animales , Fiebre Porcina Africana/diagnóstico , Fiebre Porcina Africana/virología , Porcinos , Reacción en Cadena de la Polimerasa/métodos , Cartilla de ADN/genética , ADN Viral/genética , Límite de Detección
2.
Molecules ; 29(9)2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38731638

RESUMEN

Copper-catalyzed azide-alkyne cycloaddition click (CuAAC) reaction is widely used to synthesize drug candidates and other biomolecule classes. Homogeneous catalysts, which consist of copper coordinated to a ligand framework, have been optimized for high yield and specificity of the CuAAC reaction, but CuAAC reaction with these catalysts requires the addition of a reducing agent and basic conditions, which can complicate some of the desired syntheses. Additionally, removing copper from the synthesized CuAAC-containing biomolecule is necessary for biological applications but inconvenient and requires additional purification steps. We describe here the design and synthesis of a PNN-type pincer ligand complex with copper (I) that stabilizes the copper (I) and, therefore, can act as a CuAAC catalyst without a reducing agent and base under physiologically relevant conditions. This complex was immobilized on two types of resin, and one of the immobilized catalyst forms worked well under aqueous physiological conditions. Minimal copper leaching was observed from the immobilized catalyst, which allowed its use in multiple reaction cycles without the addition of any reducing agent or base and without recharging with copper ion. The mechanism of the catalytic cycle was rationalized by density functional theory (DFT). This catalyst's utility was demonstrated by synthesizing coumarin derivatives of small molecules such as ferrocene and sugar.


Asunto(s)
Alquinos , Azidas , Química Clic , Cobre , Reacción de Cicloadición , Cobre/química , Química Clic/métodos , Ligandos , Catálisis , Azidas/química , Alquinos/química , Cumarinas/química , Compuestos Ferrosos/química , Metalocenos/química , Estructura Molecular
3.
Chembiochem ; 24(4): e202200590, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36471561

RESUMEN

While most FDA-approved peptide drugs are cyclic, the robust cyclization chemistry of peptides and the deconvolution of cyclic peptide sequences by using tandem mass spectrometry render cyclic peptide drug discovery difficult. Here we present the successful design of cyclic peptides on solid phase that addresses both of these problems. We demonstrate that this peptide cyclization method using dichloro-s-tetrazine on solid phase allows successful cyclization of a panel of random peptide sequences with various charges and hydrophobicities. The cyclic peptides can be linearized and cleaved from the solid phase by simple UV light irradiation, and we demonstrate that accurate sequence information can be obtained for the UV-cleaved linearized peptides by using tandem mass spectrometry. The tetrazine linker used in the cyclic peptides can further be explored for inverse electron-demand Diels-Alder (IEDDA) reactions for screening or bioconjugation applications in the future.


Asunto(s)
Compuestos Heterocíclicos , Rayos Ultravioleta , Péptidos/química , Péptidos Cíclicos/química
4.
Arch Virol ; 168(3): 79, 2023 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-36740635

RESUMEN

A rapid, simple, and sensitive diagnostic technique for the detection of African swine fever virus (ASFV) nucleic acid was developed for testing clinical samples in the field or resource-constrained settings. In the current study, the saltatory rolling-circle amplification (SRCA) technique was used for the first time to detect ASFV. The technique was developed using World Organization for Animal Health (WOAH)-approved primers targeting the p72 gene of the ASFV genome. The assay can be performed within 90 minutes at an isothermal temperature of 58°C without a requirement for sophisticated instrumentation. The results can be interpreted by examination with the naked eye with the aid of SYBR Green dye. This assay exhibited 100% specificity, producing amplicons only from ASFV-positive samples, and there was no cross-reactivity with other pathogenic viruses and bacteria of pigs that were tested. The lower limits of detection of SRCA, endpoint PCR, and real-time PCR assays were 48.4 copies/µL, 4.84 × 103 copies/µL, and 4.84 × 103 copies/µL, respectively. Thus, the newly developed SRCA assay was found to be 100 times more sensitive than endpoint and real-time PCR assays. Clinical tissue samples obtained from ASFV-infected domestic pigs and other clinical samples collected during 2020-22 from animals with suspected ASFV infection were tested using the SRCA assay, and a 100% accuracy rate, negative predictive value, and positive predictive value were demonstrated. The results indicate that the SRCA assay is a simple yet sensitive method for the detection of ASFV that may improve the diagnostic capacity of field laboratories, especially during outbreaks. This novel diagnostic technique is completely compliant with the World Health Organization's "ASSURED" criteria advocated for disease diagnosis, as it is affordable, specific, sensitive, user-friendly, rapid and robust, equipment-free, and deliverable. Therefore, this SRCA assay may be preferable to other complex molecular techniques for diagnosing African swine fever.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Porcinos , Animales , Virus de la Fiebre Porcina Africana/genética , Fiebre Porcina Africana/diagnóstico , ADN Viral/genética , Sensibilidad y Especificidad , Sus scrofa , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos
5.
World J Microbiol Biotechnol ; 40(1): 14, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37966568

RESUMEN

Staphylococcus aureus is an important and leading cause of foodborne diseases worldwide. Prompt detection and recall of contaminated foods are crucial to prevent untoward health consequences caused by S. aureus. Helix loop-mediated isothermal amplification (HAMP) is an exciting recent addition to the array of available isothermal-based nucleic acid amplification techniques. This study aimed to develop and evaluate a HAMP assay for detecting S. aureus in milk and milk products. The assay is completed in 75 minutes of isothermal temperature incubation (64 ˚C) and dye-based visual interpretation of results based on colour change. The specificity of the developed assay was ascertained using 27 S. aureus and 17 non S. aureus bacterial strains. The analytical sensitivity of the developed HAMP assay was 9.7 fg/µL of pure S. aureus DNA. The detection limit of the HAMP assay in milk (86 CFU/mL) was 1000x greater than the routinely used endpoint PCR (86 × 103 CFU/mL). The practicality of applying the HAMP assay was also assessed by analysing milk and milk product samples (n = 95) obtained from different dairy farms and retail outlets. The developed test is a more rapid, sensitive, and user-friendly method for the high-throughput screening of S. aureus in food samples and may therefore be suitable for field laboratories. To our knowledge, this is the first study to develop and evaluate the HAMP platform for detecting S. aureus.


Asunto(s)
Leche , Infecciones Estafilocócicas , Humanos , Animales , Staphylococcus aureus/genética , Colorimetría , Técnicas de Amplificación de Ácido Nucleico , Hepcidinas
6.
Food Microbiol ; 107: 104066, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35953186

RESUMEN

The developed polymerase spiral reaction-based technique specifically amplified the ceuE gene of C. coli and involved a three-step centrifugation method for DNA extraction. PSR, real-time and end-point PCR were able to detect 62 fg, 620 fg and 6.2 pg C. coli DNA/tube, respectively. PSR detection limits for artificially contaminated pork samples without enrichment, with 12 h enrichment and after 24 h enrichment were 1000 CFU/g, 100 CFU/g, and 10 CFU/g samples, respectively which were ten times better than real-time PCR. The detection performance of PSR (with 12 h enrichment) was also compared to culture (ISO10272-1:2017) method using 75 naturally-contaminated samples, which revealed the sensitivity, specificity, PPV, NPV and accuracy of 100% (95%CI, 73.2%-100%), 98.4% (95%CI, 90%-99.9%), 93.3% (95%CI, 66%-99.6%), 100% (95%CI, 92.5%-100%) and 98.7% (95%CI, 92.8%-99.9%), respectively. The advantage and novelty of this assay are its equipment-free nature, dye-based interpretation by the naked eye, and the requirement of one enzyme and one primer pair. This assay could be a better alternative to other molecular methods and may help in reducing the possible troubles (e.g., gastroenteritis, hospitalization, or death) of belated detection of C. coli in food products. This is the primary report applying the PSR for C. coli detection.


Asunto(s)
Campylobacter coli , Carne de Cerdo , Carne Roja , Animales , Campylobacter coli/genética , ADN , Microbiología de Alimentos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Sensibilidad y Especificidad , Porcinos
7.
Anaerobe ; 77: 102618, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35933078

RESUMEN

BACKGROUND AND OBJECTIVES: Clostridium perfringens (C. perfringens), is a spore-forming and toxin-producing pathogenic Gram-positive rod-shaped bacterium with immense public health/zoonotic concern. Rodents are well-known reservoirs and vectors for a large number of zoonoses and strong links have been recognized between synanthropic rodents and foodborne disease outbreaks throughout the world. To date, no study has been conducted for studying the prevalence of C. perfringens in rodents and shrews. In this study, we investigated faecal samples from free-living rodents and shrews trapped in Meghalaya, a North-eastern hill state of India for the presence of virulent and antimicrobial-resistant C. perfringens. METHODS: A total of 122 animals comprising six species of rodents and one species of shrews were trapped: Mus musculus (n = 15), Mus booduga (n = 7), Rattus rattus (n = 9), Rattus norvegicus (n = 3), Bandicota indica (n = 30), Bandicota bengalensis (n = 32) and Suncus murinus (n = 26). The faecal swabs were collected and processed for the isolation of C. perfringens. Toxinotyping was done using PCR. Antimicrobial susceptibility testing and biofilm forming ability testing were done using Kirby Bauer disc diffusion method and crystal violet assay. RESULTS: C. perfringens was isolated from 27 of the 122 faecal swabs (22.1%), from six species of rodents and shrews. Five of the host species were rodents, Bandicota bengalensis (25%), Bandicota indica (16.7%), Rattus norvegicus (33.3%), Mus musculus (13.3%), Mus booduga (42.8%) and Suncus murinus (shrew) (29.6%). The common toxinotype was type A (59.2%) followed by Type A with beta2 toxin (33.3%), Type C (3.7%) and Type C with beta2 toxin (3.7%). None of the isolates harboured cpe, etx, iap, and NetB genes and therefore none was typed as either B, D, E, F, or G. Nine isolates (33.3%) turned out to be multi-drug resistant (MDR), displaying resistance to three or more categories of antibiotics tested. Twenty-three out of twenty-seven isolates (85.2%) were forming biofilms. CONCLUSION: Globally, this is the first study to report the prevalence of C. perfringens and its virulence profile and antimicrobial resistance in free-living rodents and shrews. The rodents and shrews can potentially contaminate the food and environment and can infect humans and livestock with multi-drug resistant/virulent Type A and Type C C. perfringens.


Asunto(s)
Infecciones por Clostridium , Musarañas , Ratones , Ratas , Animales , Humanos , Musarañas/microbiología , Clostridium perfringens/genética , Prevalencia , Biopelículas , Murinae , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/veterinaria , Infecciones por Clostridium/microbiología
8.
AAPS PharmSciTech ; 23(7): 277, 2022 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-36229571

RESUMEN

NIR spectroscopy is a non-destructive characterization tool for the blend uniformity (BU) assessment. However, NIR spectra of powder blends often contain overlapping physical and chemical information of the samples. Deconvoluting the information related to chemical properties from that associated with the physical effects is one of the major objectives of this work. We achieve this aim in two ways. Firstly, we identified various sources of variability that might affect the BU results. Secondly, we leverage the machine learning-based sophisticated data analytics processes. To accomplish the aforementioned objectives, calibration samples of amlodipine as an active pharmaceutical ingredient (API) with the concentrations ranging between 67 and 133% w/w (dose ~ 3.6% w/w), in powder blends containing excipients, were prepared using a gravimetric approach and assessed using NIR spectroscopic analysis, followed by HPLC measurements. The bias in NIR results was investigated by employing data quality metrics (DQM) and bias-variance decomposition (BVD). To overcome the bias, the clustered regression (non-parametric and linear) was applied. We assessed the model's performance by employing the hold-out and k-fold internal cross-validation (CV). NIR-based blend homogeneity with low mean absolute error and an interval estimates of 0.674 (mean) ± 0.218 (standard deviation) w/w was established. Additionally, bootstrapping-based CV was leveraged as part of the NIR method lifecycle management that demonstrated the mean absolute error (MAE) of BU ± 3.5% w/w and BU ± 1.5% w/w for model generalizability and model transferability, respectively. A workflow integrating machine learning to NIR spectral analysis was established and implemented. Impact of various data learning approaches on NIR spectral data.


Asunto(s)
Excipientes , Espectroscopía Infrarroja Corta , Amlodipino , Artefactos , Sesgo , Calibración , Química Farmacéutica/métodos , Composición de Medicamentos/métodos , Excipientes/química , Aprendizaje Automático , Polvos/química , Espectroscopía Infrarroja Corta/métodos , Comprimidos , Tecnología Farmacéutica/métodos
9.
J Biol Chem ; 295(5): 1202-1211, 2020 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-31852737

RESUMEN

Sex hormone-binding globulin (SHBG) determines the equilibrium between free and protein-bound androgens and estrogens in the blood and regulates their access to target tissues. Using crystallographic approaches and radiolabeled competitive binding-capacity assays, we report here how two nonsteroidal compounds bind to human SHBG, and how they influence androgen activity in cell culture. We found that one of these compounds, (-)3,4-divanillyltetrahydrofuran (DVT), present in stinging nettle root extracts and used as a nutraceutical, binds SHBG with relatively low affinity. By contrast, a synthetic compound, 3-(1H-imidazol-1-ylmethyl)-2phenyl-1H-indole (IPI), bound SHBG with an affinity similar to that of testosterone and estradiol. Crystal structures of SHBG in complex with DVT or IPI at 1.71-1.80 Šresolutions revealed their unique orientations in the SHBG ligand-binding pocket and suggested opportunities for the design of other nonsteroidal ligands of SHBG. As observed for estradiol but not testosterone, IPI binding to SHBG was reduced by ∼20-fold in the presence of zinc, whereas DVT binding was almost completely lost. Estradiol-dependent fibulin-2 interactions with SHBG similarly occurred for IPI-bound SHBG, but not with DVT-bound SHBG. Both DVT and IPI increased the activity of testosterone in a cell culture androgen reporter system by competitively displacing testosterone from SHBG. These findings indicate how nonsteroidal ligands of SHBG maybe designed to modulate the bioavailability of sex steroids.


Asunto(s)
Andrógenos/metabolismo , Furanos/química , Lignina/química , Globulina de Unión a Hormona Sexual/química , Cristalografía por Rayos X , Estradiol/química , Furanos/metabolismo , Humanos , Cinética , Ligandos , Lignina/metabolismo , Mutación , Globulina de Unión a Hormona Sexual/genética , Globulina de Unión a Hormona Sexual/metabolismo , Testosterona/química , Zinc/química
10.
Anaerobe ; 69: 102324, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33508439

RESUMEN

Clostridium perfringens (C. perfringens), a prolific toxin-producing anaerobe is an important foodborne pathogen with a huge public health concern. Rapid and on-site detection of C. perfringens is of specific importance in developing countries. In the present study, saltatory rolling circle amplification (SRCA) assay was developed for culture-independent, rapid and visual detection of C. perfringens and evaluated in meat with pork as a model. The specificity of the SRCA assay was ascertained by using 62 C. perfringens and 18 non- C. perfringens strains. The analytical sensitivity of the developed SRCA, conventional and real-time PCR assays were 80 fg, 800 fg and 800 fg DNA per tube, respectively. The limit of detection of the SRCA assay was 80 CFU/g of pork in the absence of enrichment and 8 CFU/g after short enrichment of 6 h. The detection limits of 80 CFU/g and 8 CFU/g of pork were attained within 120 min and 8 h, respectively. Real-world or field relevancy of the developed assay was evaluated by screening 82 raw and processed pork samples. As the developed assay is simple, user-friendly, cost-effective and sophisticated-equipment free, it would be more suitable for on-site testing of C. perfringens in foods. To our information, this is the first report to apply SRCA for the detection of C. perfringens.


Asunto(s)
Clostridium perfringens/aislamiento & purificación , Microbiología de Alimentos/métodos , Genoma Bacteriano , Técnicas de Diagnóstico Molecular/métodos , Carne de Cerdo/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Animales , Especificidad de la Especie , Porcinos
11.
Mol Cell Probes ; 50: 101510, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31953220

RESUMEN

The polymerase spiral reaction (PSR), a novel isothermal method for targeted DNA amplification, was effectively applied to detect Salmonella in artificially spiked pork. The specificity of the developed PSR was tested using 16 Salmonella and 15 non-Salmonella strains. The PSR assay was 10-fold more sensitive than conventional end-point PCR, having a sensitivity comparable to real-time PCR. The limit of detection of the developed assay was 4 × 103 per gram of pork without enrichment and 4 CFU per gram after a 6 h enrichment. The detection of 4 CFU per gram of pork was achieved within 8 h. The PSR assay was successful, and accurate in comparison to microbiological methods, in detecting Salmonella in 11 of 76 commercial pork samples. Therefore the positive predictive value, negative predictive value and accuracy rate of the developed assay were 100%. Considering its rapidity, user-friendliness, simplicity, cost-effectiveness and equipment-free nature, this PSR assay is a promising tool for the food industry for the detection of Salmonella and prevention of Salmonella outbreaks and recalls.


Asunto(s)
Productos de la Carne/microbiología , Carne de Cerdo/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Salmonella/aislamiento & purificación , Bioensayo , Contaminación de Alimentos/análisis , Límite de Detección
13.
Can J Neurol Sci ; 46(5): 499-511, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31309917

RESUMEN

BACKGROUND: The Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) cohort study of the Canadian Consortium on Neurodegeneration in Aging (CCNA) is a national initiative to catalyze research on dementia, set up to support the research agendas of CCNA teams. This cross-country longitudinal cohort of 2310 deeply phenotyped subjects with various forms of dementia and mild memory loss or concerns, along with cognitively intact elderly subjects, will test hypotheses generated by these teams. METHODS: The COMPASS-ND protocol, initial grant proposal for funding, fifth semi-annual CCNA Progress Report submitted to the Canadian Institutes of Health Research December 2017, and other documents supplemented by modifications made and lessons learned after implementation were used by the authors to create the description of the study provided here. RESULTS: The CCNA COMPASS-ND cohort includes participants from across Canada with various cognitive conditions associated with or at risk of neurodegenerative diseases. They will undergo a wide range of experimental, clinical, imaging, and genetic investigation to specifically address the causes, diagnosis, treatment, and prevention of these conditions in the aging population. Data derived from clinical and cognitive assessments, biospecimens, brain imaging, genetics, and brain donations will be used to test hypotheses generated by CCNA research teams and other Canadian researchers. The study is the most comprehensive and ambitious Canadian study of dementia. Initial data posting occurred in 2018, with the full cohort to be accrued by 2020. CONCLUSION: Availability of data from the COMPASS-ND study will provide a major stimulus for dementia research in Canada in the coming years.


Évaluation complète d'une étude de cohorte canadienne portant sur la démence et la neuro-dégénérescence. Contexte : L'évaluation globale de la neuro-dégénérescence et de la démence (COMPASS-ND), étude de cohorte du Consortium canadien en neuro-dégénérescence associée au vieillissement (CCNV), représente une initiative nationale visant à promouvoir la recherche portant sur la démence et à soutenir les programmes de recherche des équipes du CCNV. Totalisant 2310 sujets recrutés partout au pays, cette cohorte longitudinale regroupe des individus fortement « phénotypés ¼ qui présentent diverses formes de démence et de pertes de mémoire légères. En plus de sujets âgés dont les fonctions cognitives sont intactes, ces 2310 sujets ont permis de valider les hypothèses formulées par les équipes du CCNV. Méthodes : Nous avons utilisé de nombreux documents pour décrire cette étude : le protocole de la COMPASS-ND ; la demande initiale de subvention ; le cinquième rapport d'étape semi-annuel du CCNV soumis aux Instituts de recherche en santé du Canada (IRSC) en décembre 2017 ; ainsi que d'autres documents produits à la suite de modifications consécutives à la mise en œuvre de ce projet. Résultats: L'étude de cohorte COMPASS-ND du CCNV inclut des participants de partout au Canada dont les divers états cognitifs sont associés à des maladies neurodégénératives ou au risque d'en souffrir. Ils feront l'objet d'un large éventail d'examens expérimentaux, cliniques, génétiques et d'imagerie afin d'aborder de manière spécifique les causes, le diagnostic, le traitement et la prévention de ces états cognitifs chez les personnes âgées. Les données obtenues à la suite d'évaluations cliniques et cognitives, ainsi que celles issues d'échantillons biologiques, d'imagerie cérébrale, de tests génétiques et de dons de cerveaux, seront utilisées pour tester les hypothèses générées par les équipes de recherche du CCNV et d'autres chercheurs canadiens. Cette étude constitue donc à ce jour l'étude canadienne la plus complète et la plus ambitieuse au sujet de la démence. La présentation des données initiales ayant eu lieu en 2018, la cohorte devrait atteindre sa taille maximale d'ici à 2020.Conclusion : La disponibilité des données de l'étude COMPASS-ND stimulera considérablement la recherche sur la démence au Canada au cours des prochaines années.


Asunto(s)
Envejecimiento , Demencia , Enfermedades Neurodegenerativas , Proyectos de Investigación , Canadá , Estudios de Cohortes , Femenino , Humanos , Estudios Longitudinales , Masculino
14.
Cereb Cortex ; 27(3): 1709-1720, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28062515

RESUMEN

Initiating joint attention (IJA), the behavioral instigation of coordinated focus of 2 people on an object, emerges over the first 2 years of life and supports social-communicative functioning related to the healthy development of aspects of language, empathy, and theory of mind. Deficits in IJA provide strong early indicators for autism spectrum disorder, and therapies targeting joint attention have shown tremendous promise. However, the brain systems underlying IJA in early childhood are poorly understood, due in part to significant methodological challenges in imaging localized brain function that supports social behaviors during the first 2 years of life. Herein, we show that the functional organization of the brain is intimately related to the emergence of IJA using functional connectivity magnetic resonance imaging and dimensional behavioral assessments in a large semilongitudinal cohort of infants and toddlers. In particular, though functional connections spanning the brain are involved in IJA, the strongest brain-behavior associations cluster within connections between a small subset of functional brain networks; namely between the visual network and dorsal attention network and between the visual network and posterior cingulate aspects of the default mode network. These observations mark the earliest known description of how functional brain systems underlie a burgeoning fundamental social behavior, may help improve the design of targeted therapies for neurodevelopmental disorders, and, more generally, elucidate physiological mechanisms essential to healthy social behavior development.


Asunto(s)
Atención/fisiología , Encéfalo/crecimiento & desarrollo , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Desarrollo Infantil/fisiología , Preescolar , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/fisiología , Pruebas Neuropsicológicas , Psicología Infantil
15.
J Biol Chem ; 291(21): 11300-12, 2016 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-27026706

RESUMEN

Corticosteroid-binding globulin (CBG) was isolated from chicken serum and identified by mass spectrometry and genomic analysis. This revealed that the organization and synteny of avian and mammalian SerpinA6 genes are conserved. Recombinant zebra finch CBG steroid-binding properties reflect those of the natural protein in plasma and confirm its identity. Zebra finch and rat CBG crystal structures in complex with cortisol resemble each other, but their primary structures share only ∼40% identity, and their steroid-binding site topographies differ in several unexpected ways. Remarkably, a tryptophan that anchors ligands in mammalian CBG steroid-binding sites is replaced by an asparagine. Phylogenetic comparisons show that reptilian CBG orthologs share this unexpected property. Glycosylation of this asparagine in zebra finch CBG does not influence its steroid-binding affinity, but we present evidence that it may participate in protein folding and steroid-binding site formation. Substitutions of amino acids within zebra finch CBG that are conserved only in birds reveal how they contribute to their distinct steroid-binding properties, including their high (nanomolar) affinities for glucocorticoids, progesterone, and androgens. As in mammals, a protease secreted by Pseudomonas aeruginosa cleaves CBG in zebra finch plasma within its reactive center loop and disrupts steroid binding, suggesting an evolutionarily conserved property of CBGs. Measurements of CBG mRNA in zebra finch tissues indicate that liver is the main site of plasma CBG production, and anti-zebra finch CBG antibodies cross-react with CBGs in other birds, extending opportunities to study how CBG regulates the actions of glucocorticoids and sex steroids in these species.


Asunto(s)
Proteínas Aviares/sangre , Proteínas Aviares/genética , Aves/sangre , Aves/genética , Evolución Molecular , Transcortina/genética , Transcortina/metabolismo , Adaptación Fisiológica , Secuencia de Aminoácidos , Animales , Proteínas Aviares/química , Pollos/sangre , Pollos/genética , Cristalografía por Rayos X , Pinzones/sangre , Pinzones/genética , Glicosilación , Modelos Moleculares , Filogenia , Ratas , Homología de Secuencia de Aminoácido , Gorriones/sangre , Gorriones/genética , Transcortina/química
16.
Neuroimage ; 124(Pt B): 1182-1187, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25896932

RESUMEN

In contrast with other imaging modalities, there is presently a scarcity of fully open resources in magnetoencephalography (MEG) available to the neuroimaging community. Here we present a collaborative effort led by the McConnell Brain Imaging Centre of the Montreal Neurological Institute, and the Université de Montréal to build and share a centralised repository to curate MEG data in raw and processed form for open dissemination. The Open MEG Archive (OMEGA, omega.bic.mni.mcgill.ca) is bound to become a continuously expanding repository of multimodal data with a primary focus on MEG, in addition to storing anatomical MRI volumes, demographic participant data and questionnaires, and other forms of electrophysiological data such as EEG. The OMEGA initiative offers both the technological framework for multi-site MEG data aggregation, and serves as one of the largest freely available resting-state and eventually task-related MEG datasets presently available.


Asunto(s)
Bases de Datos Factuales , Difusión de la Información , Magnetoencefalografía , Electroencefalografía , Humanos , Imagen por Resonancia Magnética , Neuroimagen
17.
Neuroimage ; 124(Pt B): 1188-1195, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26364860

RESUMEN

Neuroimaging has been facing a data deluge characterized by the exponential growth of both raw and processed data. As a result, mining the massive quantities of digital data collected in these studies offers unprecedented opportunities and has become paramount for today's research. As the neuroimaging community enters the world of "Big Data", there has been a concerted push for enhanced sharing initiatives, whether within a multisite study, across studies, or federated and shared publicly. This article will focus on the database and processing ecosystem developed at the Montreal Neurological Institute (MNI) to support multicenter data acquisition both nationally and internationally, create database repositories, facilitate data-sharing initiatives, and leverage existing software toolkits for large-scale data processing.


Asunto(s)
Bases de Datos Factuales , Difusión de la Información , Neuroimagen , Conducta , Genómica , Humanos , Estudios Longitudinales , Control de Calidad , Programas Informáticos
18.
J Pept Sci ; 22(4): 196-200, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26880702

RESUMEN

Abnormal signaling of the protein kinase Akt has been shown to contribute to human diseases such as diabetes and cancer, but Akt has proven to be a challenging target for drugging. Using iterative in situ click chemistry, we recently developed multiple protein-catalyzed capture (PCC) agents that allosterically modulate Akt enzymatic activity in a protein-based assay. Here, we utilize similar PCCs to exploit endogenous protein degradation pathways. We use the modularity of the anti-Akt PCCs to prepare proteolysis targeting chimeric molecules that are shown to promote the rapid degradation of Akt in live cancer cells. These novel proteolysis targeting chimeric molecules demonstrate that the epitope targeting selectivity of PCCs can be coupled with non-traditional drugging moieties to inhibit challenging targets.


Asunto(s)
Antineoplásicos/farmacología , Péptidos/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Catálisis , Línea Celular Tumoral , Proliferación Celular , Ensayos de Selección de Medicamentos Antitumorales , Activación Enzimática , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Concentración 50 Inhibidora , Terapia Molecular Dirigida , Proteolisis
20.
Antonie Van Leeuwenhoek ; 109(7): 945-56, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27075453

RESUMEN

Aeromonas species are important pathogens of fishes and aquatic animals capable of infecting humans and other animals via food. Due to the paucity of pan-genomic studies on aeromonads, the present study was undertaken to analyse the pan-genome of three clinically important Aeromonas species (A. hydrophila, A. veronii, A. caviae). Results of pan-genome analysis revealed an open pan-genome for all three species with pan-genome sizes of 9181, 7214 and 6884 genes for A. hydrophila, A. veronii and A. caviae, respectively. Core-genome: pan-genome ratio (RCP) indicated greater genomic diversity for A. hydrophila and interestingly RCP emerged as an effective indicator to gauge genomic diversity which could possibly be extended to other organisms too. Phylogenomic network analysis highlighted the influence of homologous recombination and lateral gene transfer in the evolution of Aeromonas spp. Prediction of virulence factors indicated no significant difference among the three species though analysis of pathogenic potential and acquired antimicrobial resistance genes revealed greater hazards from A. hydrophila. In conclusion, the present study highlighted the usefulness of whole genome analyses to infer evolutionary cues for Aeromonas species which indicated considerable phylogenomic diversity for A. hydrophila and hitherto unknown genomic evidence for pathogenic potential of A. hydrophila compared to A. veronii and A. caviae.


Asunto(s)
Aeromonas caviae/genética , Aeromonas hydrophila/genética , Aeromonas veronii/genética , Aeromonas caviae/efectos de los fármacos , Aeromonas caviae/patogenicidad , Aeromonas hydrophila/efectos de los fármacos , Aeromonas hydrophila/patogenicidad , Aeromonas veronii/efectos de los fármacos , Aeromonas veronii/patogenicidad , Animales , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Evolución Molecular , Transferencia de Gen Horizontal , Variación Genética , Genoma Bacteriano , Genotipo , Recombinación Homóloga , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Virulencia/genética , Factores de Virulencia/genética
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