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1.
Sci Rep ; 14(1): 20592, 2024 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-39232045

RESUMEN

Human longevity leaders with remarkably long lifespan play a crucial role in the advancement of longevity research. In this paper, we propose a stochastic model to describe the evolution of the age of the oldest person in the world by a Markov process, in which we assume that the births of the individuals follow a Poisson process with increasing intensity, lifespans of individuals are independent and can be characterized by a gamma-Gompertz distribution with time-dependent parameters. We utilize a dataset of the world's oldest person title holders since 1955, and we compute the maximum likelihood estimate for the parameters iteratively by numerical integration. Based on our preliminary estimates, the model provides a good fit to the data and shows that the age of the oldest person alive increases over time in the future. The estimated parameters enable us to describe the distribution of the age of the record holder process at a future time point.


Asunto(s)
Longevidad , Cadenas de Markov , Humanos , Distribución por Edad , Anciano de 80 o más Años
2.
Sci Total Environ ; 948: 174282, 2024 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-38960164

RESUMEN

Poisoning caused by coumarin-type anticoagulant rodenticides (ARs) stands as the predominant method for controlling rodents globally. ARs, through secondary poisoning, pose a significant threat to predators due to their lethal and sublethal effects. We examined the concentration of accumulated ARs in liver samples of mostly road-killed steppe polecats (Mustela eversmanii) and European polecats (M. putorius) collected throughout Hungary between 2005 and 2021. The steppe polecat samples were found mainly from Eastern Hungary, while European polecats from Western Hungary. We measured the concentration of six residues by HPLC-FLD. Our analysis revealed the presence of one first-generation and four second-generation ARs in 53% of the steppe polecat (36) and 39% of the European polecat (26) samples. In 17 samples we detected the presence of at least two AR compounds. Although we did not find significant variance in AR accumulation between the two species, steppe polecats displayed greater prevalence and maximum concentration of ARs, whereas European polecat samples exhibited a more diverse accumulation of these compounds. Brodifacoum and bromadiolone were the most prevalent ARs; the highest concentrations were 0.57 mg/kg and 0.33 mg/kg, respectively. The accumulation of ARs was positively correlated with human population density and negatively correlated with the extent of the more natural habitats in both species. To the best of our knowledge, this is the first study to demonstrate anticoagulant rodenticide exposure in steppe polecats globally, and for European polecats in Central European region. Although the extent of AR accumulation in European polecat in Hungary appears comparatively lower than in many other European countries, the issue of secondary poisoning remains a serious problem as these ARs intrude into food webs. Reduced and more prudent usage of pesticides would provide several benefits for wildlife, included humans. However, we advocate a prioritization of ecosystem services through the complete prohibition of the toxicants.


Asunto(s)
Anticoagulantes , Monitoreo del Ambiente , Rodenticidas , Animales , Anticoagulantes/análisis , Hungría , Mustelidae , Contaminantes Ambientales/análisis
3.
Heliyon ; 9(4): e15025, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37095951

RESUMEN

This article aims to examine the relationship between job crafting activities and employees' readiness to change. Confirmatory factor analysis and hierarchical regression analysis were conducted on a representative sample of 500 employees. Sampling was carried out in a European country in a period strongly affected by COVID-19 to isolate the five dimensions of job crafting and their separate effects on employees' readiness to change. The findings show that the five dimensions of job crafting can be distinguished from each other and that they have differential effects on employees' readiness to change. Extending task crafting shows a positive relationship with employees' readiness to change while reducing task crafting showed no significant relationship. Surprisingly extending and reducing relationship crafting showed no significant relationship with readiness to change. Cognitive crafting was found to be significantly positively related to the dependent variable. This research contributes to the development of job crafting theory by providing empirical support that job crafting can be associated with readiness to change but that this relationship may vary across its dimensions. The results may also provide important conclusions for change leaders and HR professionals.

4.
Behav Sci (Basel) ; 13(2)2023 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-36829362

RESUMEN

This study investigates how compatibility and perceived enjoyment affect the link between intention to use and actual technology use in Romanian preschool education, building on earlier studies. METHODS: 300 participants were invited to participate in this research from 15 Romanian counties. 182 preschool teachers' questionnaires were utilized for data analysis after the return and screening of responses. A valid and accurate scale evaluating preschool teachers' behavior towards technology adoption was included in the questionnaire, along with self-reported demographic data, professional identification, and other information. Data was analyzed using SPSS V.16. RESULTS: (1) Intention to use, compatibility, perceived enjoyment, and actual use were positively associated. (2) The effect of compatibility and perceived enjoyment on the link between intention to use and actual technology use was carried out in the following way: Intention to use → Compatibility with technology → Perceived enjoyment → Actual use. We hypothesize that intention to use affects compatibility, compatibility affects perceived enjoyment, and, lastly, perceived enjoyment affects actual use. For a more robust validation of results, we have also modelled this relationship with the Radial Basis Function (RBF) neural network. CONCLUSION: Compatibility and perceived enjoyment partially mediate the relationship between intention to use and actual technology use in class by Romanian preschool teachers. According to the theory of planned behavior, this study brought to light the intricacy of the relationship between preschool teachers' intention to utilize technology in the classroom and their actual usage of it. Limitations and implications are discussed.

5.
Front Psychol ; 13: 955833, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35936241

RESUMEN

According to Sustainable Development Goal 4.2 (SDG 4.2), Equal Access to Quality Pre-primary Education, governments throughout the world are working to ensure that all children have access to high-quality early childhood development, care, and pre-primary education by 2030. In order to organize available evidence into a coherent framework, the current scoping review represents an exploratory synthesis addressing the broad question of what qualitative and inclusive Early Childhood Education and Care strategies are currently being established globally to achieve SDG4 targets. The goal of this scoping review in this respect, was to map the available research and offer an overview of micro-, meso-, and macro-level perspectives on evidence-based interventions and strategies, for the promotion of SDG4 globally. A layered model of early childhood education that is both inclusive and egalitarian education emerged, starting with the micro level: child, family and community, mezo level: nursery, and kindergarten and macro level: national policies and SDG 4.2 Agenda for 2030. The mezzo level connects the micro and macro levels, being the most solicited level of implementing inclusive and qualitative ECEC strategies. Thus, starting with putting a real emphasis on children rights, creating a qualitative and inclusive culture with a holistic understanding of child development, then investing in teacher preparation and instilling a strong belief and positive attitudes toward equity in early childhood services, developing inclusive educational policies with an authentic community support offered by all stakeholders, then adapting curriculum and assessment methods to all early childhood educational contexts and lastly piloting and up-scaling good practices, and investing in infrastructure, facilities and innovative educational services, SDG4.2 targets could transparently and efficiently be attained by 2030, with all the setbacks arisen from the pandemic context. The data provide light on a vast topic range, including human rights and values, policy actions, and ideologies. The micro-level themes emphasized the importance of fostering equitable and inclusive environments for children., as well as instructional approaches that encourage positive attitudes toward diversity and instructors' levels of experience in dealing with diversity. We also discovered the significance of creating chances that promote socialization, connection development, and a sense of belonging. Meso-level principles emphasized the relevance of schooling in a child's holistic development and skill acquisition. Mainstream availability for all children, national curriculum regulations, teacher preparation for inclusive early childhood education, excellent funding and governance, evaluation and monitoring, and research on inclusive early childhood education comprise the macro level. As a concept and an approach, inclusive and qualitative education necessitates the preparedness of all relevant educational components to participate. Providing inclusive education in the early years requires setting the foundation for subsequent levels of schooling. The active engagement of a young kid should be directed by developmentally and individually suitable curricula. Access to and participation in age-appropriate general curricula becomes critical in identifying and providing specialized support services. Inclusive programming does not imply that the educational programs will necessarily be of good quality. Efficiency and wellbeing are synonymous with equity. Equitable education investment benefits everyone in society, not just the most marginalized. Investing in education will help communities achieve all of the Sustainable Development Goals related to education.

6.
Front Psychol ; 13: 1017011, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36698596

RESUMEN

Predicting preschool teachers' intention to adopt qualitative and inclusive early childhood intentional behaviors represents an important research field. The objective of this research is first to develop and validate a scale to assess the integrative-qualitative intentional behavior (IQIB-ECEC) of preschool teachers in order to achieve SDG4.2's objective of ensuring that all children have access to high-quality pre-primary education and then to systemically analyze the relationship between variables with Network Analysis. The theory of planned behavior (TPB) describes key individual beliefs (attitudes, subjective norms, and perceived behavior control) that affect people's intentions to engage in a certain conduct and has previously been used with success in evaluating people's intentions to adopt a certain behavior. This research represents one of the first Romanian attempts to use the theory of planned behavior to study the Integrative-Qualitative Intentional Behavior in Romanian Preschool Education and systemically analyze results with Network Analysis approach. This study used a randomized 300 Romanian preschool teachers enrolled in a National Training Program entitled Qualitative and Inclusive Early Childhood Education managed by the Romanian Educational Ministry. Data were collected via an online questionnaire. The scale validation followed a confirmatory factor analysis (CFA). The fitting of the IQIB-ECEC 19-item scale showed that all coefficients CFI (0.942), TLI (0.920), SRMR (0.0452), and RMSEA (0.0451) bring strong evidence in the favor of the statistical validity of the scale. The final IQIB-ECEC 19 items and 8 factors scale obtained a Cronbach's alpha of 0.77. The systemic Network Analysis approach was used in interpreting data. The centrality of the network model was further investigated and the clustering coefficients index were calculated. According to the results, perceived power/control beliefs and behavioral intention were detected as the most important dimensions, whereas behavioral beliefs were less important. These findings were discussed in terms of their theoretical and practical significance.

7.
Acta Vet Hung ; 67(2): 246-255, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31238724

RESUMEN

The aim of the study was to find a practical and inexpensive method for freezing goose semen for use in routine inseminations under farm conditions. Two basic freezing protocols [(1) dynamic, programmable freezing and (2) static, nitrogen vapour method] were evaluated with varying concentrations of dimethylformamide (DMF) plus additional osmoprotectants such as betaine, trehalose, and sucrose, using cryovials as containers. Altogether eight different treatments were compared. sperm viability before freezing and after thawing was examined by in vitro tests and, in the case of the simplest effective method, also by in vivo fertility test. There were no significant differences in sperm survival either in the dynamic (48-50%) or in the static protocol (43-46%), except for the treatment where the lowest DMF concentration was used without any osmoprotectant in the dynamic protocol (42.6%). The addition of osmoprotectants did not improve thawed sperm viability in any case. Fertility with frozen/thawed sperm using the simplest method was 58.5%, while that obtained with fresh, diluted semen was 66.9%. The study proved that the simple freezing of gander semen in nitrogen vapour with 9% DMF in cryovials could produce acceptable fertility. The newly elaborated method can be successfully used for routine inseminations by small- and large-scale goose breeders.


Asunto(s)
Criopreservación/métodos , Preservación de Semen/veterinaria , Semen/fisiología , Animales , Congelación , Gansos , Masculino , Nitrógeno/análisis , Análisis de Semen/veterinaria , Preservación de Semen/métodos
8.
Int J Paleopathol ; 24: 108-118, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30342349

RESUMEN

OBJECTIVE: The prevalence of hyperostosis frontalis interna (HFI) was examined in different periods of the Carpathian Basin from 4900 BCE to 17th century AD. The study seeks to evaluate temporal changes in HFI and the possible impact of lifestyle on it. MATERIALS: The studied material consisted of 4668 crania from Hungary and Serbia. METHODS: The crania were analyzed employing macroscopic and endoscopic examination. RESULTS: In historic periods, sex and age played a pivotal role in HFI development. Among predominantly pastoralist populations of the 5th-8th and 10th centuries, prevalence of HFI was considerably higher than in the medieval populations of the 9th-17th centuries. CONCLUSIONS: In addition to age and sex, other factors could be implicated in HFI development. The physiological effects of the pastoralist lifestyle and diet on insulin regulation could explain the increased risk of developing HFI in the 5th-8th and 10th-century populations. SIGNIFICANCE: The study provides the first comprehensive dataset of HFI from different archaeological periods from the Carpathian Basin. It has implications for lifestyle and risk of HFI development in past populations. LIMITATIONS: The archaeological periods are not equally represented. SUGGESTIONS FOR FURTHER RESEARCH: In order to better understand the etiology of HFI, lifestyle factors can be used to elucidate the risk of developing HFI in ancient populations.


Asunto(s)
Hueso Frontal/patología , Hiperostosis Frontal Interna/historia , Estilo de Vida , Arqueología/historia , Arqueología/métodos , Fósiles/historia , Historia del Siglo XVI , Historia del Siglo XVII , Humanos , Hungría , Paleopatología/métodos , Prevalencia , Riesgo , Serbia
9.
J Mol Biol ; 428(9 Pt A): 1776-89, 2016 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-27000644

RESUMEN

We report the engineering of a new reversibly switching chromogenic protein, Dathail. Dathail was evolved from the extremely thermostable fluorescent proteins thermal green protein (TGP) and eCGP123 using directed evolution and ratiometric sorting. Dathail has two spectrally distinct chromogenic states with low quantum yields, corresponding to absorbance in a ground state with a maximum at 389nm, and a photo-induced metastable state with a maximum at 497nm. In contrast to all previously described photoswitchable proteins, both spectral states of Dathail are non-fluorescent. The photo-induced chromogenic state of Dathail has a lifetime of ~50min at 293K and pH7.5 as measured by UV-Vis spectrophotometry, returning to the ground state through thermal relaxation. X-ray crystallography provided structural insights supporting a change in conformation and coordination in the chromophore pocket as being responsible for Dathail's photoswitching. Neutron crystallography, carried out for the first time on a protein from the green fluorescent protein family, showed a distribution of hydrogen atoms revealing protonation of the chromophore 4-hydroxybenzyl group in the ground state. The neutron structure also supports the hypothesis that the photo-induced proton transfer from the chromophore occurs through water-mediated proton relay into the bulk solvent. Beyond its spectroscopic curiosity, Dathail has several characteristics that are improvements for applications, including low background fluorescence, large spectral separation, rapid switching time, and the ability to switch many times. Therefore, Dathail is likely to be extremely useful in the quickly developing fields of imaging and biosensors, including photochromic Förster resonance energy transfer, high-resolution microscopy, and live tracking within the cell.


Asunto(s)
Color , Procesos Fotoquímicos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Cristalografía por Rayos X , Evolución Molecular Dirigida , Modelos Moleculares , Conformación Proteica , Proteínas Recombinantes/genética , Espectrofotometría , Temperatura , Factores de Tiempo
10.
MAbs ; 7(1): 32-41, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25530082

RESUMEN

Only a small fraction of the antibodies in a traditional polyclonal antibody mixture recognize the target of interest, frequently resulting in undesirable polyreactivity. Here, we show that high-quality recombinant polyclonals, in which hundreds of different antibodies are all directed toward a target of interest, can be easily generated in vitro by combining phage and yeast display. We show that, unlike traditional polyclonals, which are limited resources, recombinant polyclonal antibodies can be amplified over one hundred million-fold without losing representation or functionality. Our protocol was tested on 9 different targets to demonstrate how the strategy allows the selective amplification of antibodies directed toward desirable target specific epitopes, such as those found in one protein but not a closely related one, and the elimination of antibodies recognizing common epitopes, without significant loss of diversity. These recombinant renewable polyclonal antibodies are usable in different assays, and can be generated in high throughput. This approach could potentially be used to develop highly specific recombinant renewable antibodies against all human gene products.


Asunto(s)
Anticuerpos , Biblioteca de Genes , Anticuerpos/química , Anticuerpos/genética , Epítopos/química , Epítopos/genética , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
11.
Protein Eng Des Sel ; 27(10): 301-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25183780

RESUMEN

The application of deep sequencing to in vitro display technologies has been invaluable for the straightforward analysis of enriched clones. After sequencing in vitro selected populations, clones are binned into identical or similar groups and ordered by abundance, allowing identification of those that are most enriched. However, the greatest strength of deep sequencing is also its greatest weakness: clones are easily identified by their DNA sequences, but are not physically available for testing without a laborious multistep process involving several rounds of polymerization chain reaction (PCR), assembly and cloning. Here, using the isolation of antibody genes from a phage and yeast display selection as an example, we show the power of a rapid and simple inverse PCR-based method to easily isolate clones identified by deep sequencing. Once primers have been received, clone isolation can be carried out in a single day, rather than two days. Furthermore the reduced number of PCRs required will reduce PCR mutations correspondingly. We have observed a 100% success rate in amplifying clones with an abundance as low as 0.5% in a polyclonal population. This approach allows us to obtain full-length clones even when an incomplete sequence is available, and greatly simplifies the subcloning process. Moreover, rarer, but functional clones missed by traditional screening can be easily isolated using this method, and the approach can be extended to any selected library (scFv, cDNA, libraries based on scaffold proteins) where a unique sequence signature for the desired clones of interest is available.


Asunto(s)
Técnicas de Visualización de Superficie Celular/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Biblioteca de Péptidos , Reacción en Cadena de la Polimerasa/métodos , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Lactobacillus acidophilus/genética , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Anticuerpos de Cadena Única , Levaduras/genética
12.
Parasitol Res ; 113(7): 2551-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24781024

RESUMEN

Hungary has a large number of thermal baths and spa facilities which attract hundreds of thousands of tourists annually. Until recently, however, the free-living amoebae were not of public health concern. Genotyping of Acanthamoeba species, potential agents of keratitis and granulomatous encephalitis, was carried out in 20 Hungarian public baths for the first time to assess the incidence and molecular diversity of the genus in the country. Our results show that 6.7% of the samples were positive for Acanthamoeba. Of these positive samples, 6.5 and 7% was from sterilized and unsterilized pools, respectively. The 18S rRNA gene investigation of the nine Acanthamoeba strains found reveals that seven belong to the hazardous T4 genotype. The remaining two samples were of the T15 type. All the strains kept growing at 36 °C. Our results underline the need to develop a control system for free-living amoebae and supervise the disinfection of Hungarian public baths.


Asunto(s)
Acanthamoeba/clasificación , Agua Dulce/parasitología , Filogenia , Instalaciones Públicas , ARN Ribosómico 18S/genética , Acanthamoeba/genética , Acanthamoeba/aislamiento & purificación , Amebiasis/epidemiología , Amebiasis/parasitología , Baños , Monitoreo Epidemiológico , Genes de ARNr , Genotipo , Humanos , Hungría/epidemiología , Incidencia
14.
MAbs ; 6(1): 160-72, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24423623

RESUMEN

In vitro selection has been an essential tool in the development of recombinant antibodies against various antigen targets. Deep sequencing has recently been gaining ground as an alternative and valuable method to analyze such antibody selections. The analysis provides a novel and extremely detailed view of selected antibody populations, and allows the identification of specific antibodies using only sequencing data, potentially eliminating the need for expensive and laborious low-throughput screening methods such as enzyme-linked immunosorbant assay. The high cost and the need for bioinformatics experts and powerful computer clusters, however, have limited the general use of deep sequencing in antibody selections. Here, we describe the AbMining ToolBox, an open source software package for the straightforward analysis of antibody libraries sequenced by the three main next generation sequencing platforms (454, Ion Torrent, MiSeq). The ToolBox is able to identify heavy chain CDR3s as effectively as more computationally intense software, and can be easily adapted to analyze other portions of antibody variable genes, as well as the selection outputs of libraries based on different scaffolds. The software runs on all common operating systems (Microsoft Windows, Mac OS X, Linux), on standard personal computers, and sequence analysis of 1-2 million reads can be accomplished in 10-15 min, a fraction of the time of competing software. Use of the ToolBox will allow the average researcher to incorporate deep sequence analysis into routine selections from antibody display libraries.


Asunto(s)
Regiones Determinantes de Complementariedad/genética , Análisis de Secuencia de ADN/métodos , Anticuerpos de Cadena Única/genética , Programas Informáticos , Regiones Determinantes de Complementariedad/inmunología , Humanos , Anticuerpos de Cadena Única/inmunología
15.
BMC Microbiol ; 13: 270, 2013 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-24279426

RESUMEN

BACKGROUND: Single cell genomics has revolutionized microbial sequencing, but complete coverage of genomes in complex microbiomes is imperfect due to enormous variation in organismal abundance and amplification bias. Empirical methods that complement rapidly improving bioinformatic tools will improve characterization of microbiomes and facilitate better genome coverage for low abundance microbes. METHODS: We describe a new approach to sequencing individual species from microbiomes that combines antibody phage display against intact bacteria with fluorescence activated cell sorting (FACS). Single chain (scFv) antibodies are selected using phage display against a bacteria or microbial community, resulting in species-specific antibodies that can be used in FACS for relative quantification of an organism in a community, as well as enrichment or depletion prior to genome sequencing. RESULTS: We selected antibodies against Lactobacillus acidophilus and demonstrate a FACS-based approach for identification and enrichment of the organism from both laboratory-cultured and commercially derived bacterial mixtures. The ability to selectively enrich for L. acidophilus when it is present at a very low abundance (<0.2%) leads to complete (>99.8%) de novo genome coverage whereas the standard single-cell sequencing approach is incomplete (<68%). We show that specific antibodies can be selected against L. acidophilus when the monoculture is used as antigen as well as when a community of 10 closely related species is used demonstrating that in principal antibodies can be generated against individual organisms within microbial communities. CONCLUSIONS: The approach presented here demonstrates that phage-selected antibodies against bacteria enable identification, enrichment of rare species, and depletion of abundant organisms making it tractable to virtually any microbe or microbial community. Combining antibody specificity with FACS provides a new approach for characterizing and manipulating microbial communities prior to genome sequencing.


Asunto(s)
Anticuerpos Antibacterianos/metabolismo , Carga Bacteriana/métodos , Citometría de Flujo/métodos , Lactobacillus acidophilus/aislamiento & purificación , Microbiota , Análisis de Secuencia de ADN/métodos , Anticuerpos de Cadena Única/metabolismo , Anticuerpos Antibacterianos/inmunología , Anticuerpos Antibacterianos/aislamiento & purificación , Técnicas de Visualización de Superficie Celular , Lactobacillus acidophilus/genética , Lactobacillus acidophilus/inmunología , Datos de Secuencia Molecular , Anticuerpos de Cadena Única/inmunología , Anticuerpos de Cadena Única/aislamiento & purificación
16.
PLoS One ; 8(9): e75835, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24098733

RESUMEN

We have developed an orange non-fluorescent photochromic protein (quantum yield, 0.003) we call Phanta that is useful as an acceptor in pcFRET applications. Phanta can be repeatedly inter-converted between the two absorbing states by alternate exposure to cyan and violet light. The absorption spectra of Phanta in one absorbing state shows excellent overlap with the emission spectra of a number of donor green fluorescent proteins including the commonly used EGFP. We show that the Phanta-EGFP FRET pair is suitable for monitoring the activation of caspase 3 in live cells using readily available instrumentation and a simple protocol that requires the acquisition of two donor emission images corresponding to Phanta in each of its photoswitched states. This the first report of a genetically encoded non-fluorescent acceptor for pcFRET.


Asunto(s)
Técnicas Biosensibles/métodos , Transferencia Resonante de Energía de Fluorescencia/métodos , Proteínas Fluorescentes Verdes/genética , Fotoquímica/métodos , Proteínas Recombinantes/biosíntesis , Secuencia de Aminoácidos , Proteínas Fluorescentes Verdes/metabolismo , Datos de Secuencia Molecular , Ingeniería de Proteínas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
17.
J Immunol Methods ; 395(1-2): 83-7, 2013 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-23850993

RESUMEN

Many applications required protein biotinylation. We routinely use biotinylated proteins to select single chain antibodies from phage and/or yeast display libraries. During phage selection the biotinylated antigens are bound to streptavidin coupled magnetic beads, while during yeast display, the biotinylated antigens are used during flow cytometry for both analysis and sorting. The Lightning-Link® Biotin kit, a rapid straightforward biotinylation kit that avoids the need for dialysis, is particularly useful when the amount of available protein is limiting. During routine screening of antibody libraries we identified a specific clone that bound a universal neo-epitope generated only when antigens are biotinylated with the commercial Lightning-Link® kit, with an affinity of ~10nM. Non-biotinylated proteins, and those biotinylated using alternative methods - the Thermo Fisher commercial kit or in vivo biotinylation using the Avitag (Ashraf et al., 2004) - were not recognized by this antibody. Using deep sequence analysis, the specific antibody was identified as being the most abundant in a number of different selections. This indicates the need for caution when using such modifying reagents, because of the possibility of selecting antibodies against the modification, rather than the target protein, and also highlights the value of deep sequencing analysis during display based selections. Furthermore, this antibody may have great utility in the analysis of proteins biotinylated using this method.


Asunto(s)
Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/inmunología , Técnicas de Visualización de Superficie Celular/métodos , Biblioteca de Péptidos , Proteínas/genética , Proteínas/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/química , Especificidad de Anticuerpos , Biotinilación , Reacciones Cruzadas , Datos de Secuencia Molecular , Proteínas/química , Conejos , Anticuerpos de Cadena Única/química , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/inmunología
18.
ACS Nano ; 6(10): 8922-32, 2012 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-22957739

RESUMEN

We demonstrate following individual fluorescent protein constructs and individual organic dyes as they diffuse in 3-D in solution at rates up to 1 µm(2)/s over distances of several micrometers in X, Y, and Z. Our 3-D tracking method is essentially a stage scanning confocal microscope that uses a unique spatial filter geometry and active feedback 200 times/s to follow fast 3-D motion. Here we detail simulations used to find optimal feedback parameters for following individual fluorescent proteins in 3-D and show that a wide range of parameters are capable of following individual proteins diffusing at 1 µm(2)/s rates. In addition, we experimentally show that through 3-D single-molecule tracking of a protein oligomer series (monomer, dimer, and tetramer) of the fluorescent protein Azami Green one can determine the protein oligomerization state. We also perform time-resolved spectroscopy (photon pair correlation measurements) during the measured 3-D trajectories. The photon pair correlation measurements show clear fluorescence photon antibunching, demonstrating that the trajectories are of single fluorescent molecules. We note that the rates of single-molecule diffusive motion we follow (approximately 1 µm(2)/s) are comparable to or faster than many intracellular transport processes.


Asunto(s)
Algoritmos , Colorantes Fluorescentes/análisis , Imagenología Tridimensional/métodos , Microscopía Confocal/métodos , Microscopía Fluorescente/métodos , Imagen Molecular/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Compuestos Orgánicos/análisis
19.
Semin Arthritis Rheum ; 41(4): 589-98, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21959290

RESUMEN

OBJECTIVES: To determine if mixed connective tissue disease (MCTD) can be considered an independent clinical entity, to compare 3 different classification criteria for MCTD (Kasukawa, Alarcón-Segovia, and Sharp), and to define predictors (clinical features and autoantibodies) of potential evolution toward other connective tissue diseases (CTDs). METHODS: One hundred sixty-one MCTD patients were evaluated retrospectively at the diagnosis and in 2008. They were classified, at the diagnosis, according to the 3 classification criteria of MCTD (Sharp, Alarcón-Segovia, and Kasukawa) and reclassified in 2008 according to their evolution. Statistical analyses were performed to find out predictors (clinical features and autoantibodies) of evolution into other CTDs. RESULTS: After a mean of 7.9 years of disease, 57.9% of patients still satisfied MCTD classification criteria of Kasukawa; 17.3% evolved into systemic sclerosis, 9.1% into systemic lupus erythematosus, 2.5% into rheumatoid arthritis, 11.5% was reclassified as affected by undifferentiated connective tissue disease, and 1.7% as suffering from overlap syndrome. Kasukawa's criteria were more sensitive (75%) in comparison to those of Alarcón-Segovia (73%) and Sharp (42%). The presence of anti-DNA antibodies (P = 0.012) was associated with evolution into systemic lupus erythematosus; hypomotility or dilation of esophagus (P < 0.001); and sclerodactyly (P = 0.034) with evolution into systemic sclerosis. CONCLUSIONS: MCTD is a distinct clinical entity but it is evident that a subgroup of patients may evolve into another CTD during disease progression. Initial clinical features and autoantibodies can be useful to predict disease evolution.


Asunto(s)
Progresión de la Enfermedad , Enfermedad Mixta del Tejido Conjuntivo/diagnóstico , Adulto , Autoanticuerpos/inmunología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Enfermedad Mixta del Tejido Conjuntivo/clasificación , Enfermedad Mixta del Tejido Conjuntivo/inmunología , Estudios Retrospectivos
20.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 67(Pt 10): 1266-8, 2011 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-22102044

RESUMEN

Enhanced consensus green protein variant 123 (eCGP123) is an extremely thermostable green fluorescent protein (GFP) that exhibits useful negative reversible photoswitching properties. eCGP123 was derived by the application of both a consensus engineering approach and a recursive evolutionary process. Diffraction-quality crystals of recombinant eCGP123 were obtained by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The eCGP123 crystal diffracted X-rays to 2.10 Å resolution. The data were indexed in space group P1, with unit-cell parameters a = 74.63, b = 75.38, c = 84.51 Å, α = 90.96, ß = 89.92, γ = 104.03°. The Matthews coefficient (V(M) = 2.26 Å(3) Da(-1)) and a solvent content of 46% indicated that the asymmetric unit contained eight eCGP123 molecules.


Asunto(s)
Proteínas Fluorescentes Verdes/química , Procesos Fotoquímicos , Secuencia de Aminoácidos , Cristalización , Cristalografía por Rayos X , Expresión Génica , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/aislamiento & purificación , Datos de Secuencia Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Alineación de Secuencia
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