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The QUIC protocol, which was originally proposed by Google, has recently gained a remarkable presence. Although it has been shown to outperform TCP over a wide range of scenarios, there exist some doubts on whether it might be an appropriate transport protocol for IoT. In this paper, we specifically tackle this question, by means of an evaluation carried out over a real platform. In particular, we conduct a thorough characterization of the performance of the MQTT protocol, when used over TCP and QUIC. We deploy a real testbed, using commercial off-the-shelf devices, and we analyze two of the most important key performance indicators for IoT: delay and energy consumption. The results evince that QUIC does not only yield a notable decrease in the delay and its variability, over various wireless technologies and channel conditions, but it does not hinder the energy consumption.
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In this paper we analyze the performance of QUIC as a transport alternative for Internet of Things (IoT) services based on the Message Queuing Telemetry Protocol (MQTT). QUIC is a novel protocol promoted by Google, and was originally conceived to tackle the limitations of the traditional Transmission Control Protocol (TCP), specifically aiming at the reduction of the latency caused by connection establishment. QUIC use in IoT environments is not widespread, and it is therefore interesting to characterize its performance when in over such scenarios. We used an emulation-based platform, where we integrated QUIC and MQTT (using GO-based implementations) and compared their combined performance with the that exhibited by the traditional TCP/TLS approach. We used Linux containers as end devices, and the ns-3 simulator to emulate different network technologies, such as WiFi, cellular, and satellite, and varying conditions. The results evince that QUIC is indeed an appropriate protocol to guarantee robust, secure, and low latency communications over IoT scenarios.
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We report the integration of an automated chemical optical sensing unit for the parallel interrogation of 12 BICELLs in a sensing chip. The work was accomplished under the European Project Enviguard (FP7-OCEAN-2013-614057) with the aim of demonstrating an optical nano-biosensing unit for the in-situ detection of various chemical pollutants simultaneously in oceanic waters. In this context, we designed an optical sensing chip based on resonant nanopillars (R-NPs) transducers organized in a layout of twelve biophotonic sensing cells (BICELLs). The sensing chip is interrogated in reflection with a 12-channels optical spectrometer equipped with an embedded computer-on-chip performing image processing for the simultaneous acquisition and analysis (resonant mode fitting) of the 12 spectra. A microfluidic chip and an automated flow control system composed of four pumps and a multi-path micro-valve makes it possible to drive different complex protocols. A rack was designed ad-hoc for the integration of all the modules. As a proof of concept, fluids of different refractive index (RI) were flowed in the system in order to measure the time response (sensogram) of the R-NPs under optical reflectance, and assess the sensors' bulk sensitivity (285.9 ± 16.4 nm/RIU) and Limit of Detection (LoD) (2.95 × 10-6 RIUS). The real-time response under continuous flow of a sensor chip based on R-NP is showed for the first time, obtaining 12 sensograms simultaneously, featuring the unit as a potential excellent multiplexed detection system. These results indicate the high potential of the developed chemical sensing unit to be used for in-situ, multiplex and automatic optical biosensing.
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Food allergy is a common disease worldwide with over 6% of the population (200â»250 million people) suffering from any food allergy nowadays. The most dramatic increase seems to be happening in children and young people. Therefore, improvements in the diagnosis efficiency of these diseases are needed. Immunoglobulin type E (IgE) biomarker determination in human serum is a typical in vitro test for allergy identification. In this work, we used a novel biosensor based on label-free photonic transducers called BICELLs (Biophotonic Sensing Cells) for IgE detection. These BICELLs have a thin film of nitrocellulose over the sensing surface, they can be vertical optically interrogated, and are suitable for being integrated on a chip. The BICELLs sensing surface sizes used were 100 and 800 µm in diameter. We obtained calibration curves with IgE standards by immobilizating anti-IgE antibodies and identified with standard IgE calibrators in minute sample amounts (3 µL). The results, in similar assay format, were compared with commercially available ImmunoCAP®. The versatility of the interferometric nitrocellulose-based sensing surface was demonstrated since the limit of detections for BICELLs and ImmunoCAP® were 0.7 and 0.35 kU/L, respectively.
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Técnicas Biosensibles/métodos , Hipersensibilidad a los Alimentos/diagnóstico , Adolescente , Niño , Colodión , Hipersensibilidad a los Alimentos/sangre , Hipersensibilidad a los Alimentos/inmunología , Humanos , Inmunoglobulina E/sangre , InterferometríaRESUMEN
Oral cancer is one of the most prevalent forms of cancer worldwide. Carcinogenesis is a complex process, in which heterogeneity plays an important role in the development and progression of the disease. This review provides an overview of the current biological and clinical significance of circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), and exosomes for diagnosis and prognosis of oral cancer. We highlight the importance of liquid biopsyusing blood and salivawhich represents a potential alternative to solid biopsy for diagnosis and prognosis. Moreover, liquid biomarkers allow for the real-time monitoring of tumour evolution and therapeutic responses, initiating the era of personalized medicine. However, in oral cancer, the impact of liquid biopsies in clinical settings is still limited, requiring further studies to discover the best scenario for its clinical use.
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Biopsia Líquida/métodos , Neoplasias de la Boca/patología , Biomarcadores de Tumor/sangre , Ácidos Nucleicos Libres de Células/sangre , Humanos , Neoplasias de la Boca/sangre , Saliva/metabolismoRESUMEN
In our previous work we demonstrated for the first time, to the best of our knowledge, the experimental capability of resonant nanopillars (R-NP) arrays as biochemical transducers. In this Letter, we provide evidence of the capability and suitability of R-NP arrays on a chip to function as label-free optical multiplexed biosensors. R-NP are based on Si3N4/SiO2 Bragg reflectors with a cavity of SiO2. In order to demonstrate the biosensing performance, R-NP were biofunctionalized by the immobilization of IgG antibodies acting as a bioreceptor. This immobilization was carried out through the silanization of the pillars sensing surface with APTMS (3-aminopropyltrimethoxysilane). R-NP were integrated in eight different sensing arrays on a quartz surface chip. An optical fiber bundle monitored each sensing array vertically and independently after each biofunctionalization step, and subsequently after every recognition event of increasing concentrations of anti-IgGs. The results report a novel multiplexed optical biosensor made of eight sensing arrays on a chip with promising performance and yield.
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Nanoestructuras , Análisis de Secuencia por Matrices de Oligonucleótidos , Fibras Ópticas , Dióxido de Silicio , TransductoresAsunto(s)
Neoplasias Laríngeas , Terapia por Láser , Glotis , Humanos , Neoplasias Laríngeas/cirugía , Pliegues VocalesRESUMEN
OBJECTIVE: To quantify the production capacity and performance in research and technological developments of the Mexican Social Security Institute (IMSS). MATERIAL AND METHODS: We identified and analyzed information of the legislation, human and financial resources, and infrastructure addressed for research and technological development of IMSS. We analyzed whether the information on the legal framework contained key features to boost research and technological development. Information on the human, financial, and infrastructure resources were obtained from official sources. The research productivity was identified by a bibliometric analysis in 2014; productivity in technological developments was identified by intellectual products. RESULTS: The legal framework of the IMSS has several areas for improvement to boost research and technological development, especially the guidelines for technology transfer. The IMSS has 438 researchers, 39 research units, and a budget of US$ 37.4 million for research and technological development. The rate of articles published per 10 researchers was 4.8; while rate patients was 1.8. CONCLUSIONS: The IMSS has a great potential to translate research into technological developments, it is only necessary to make some changes to the legal framework.
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Academias e Institutos/estadística & datos numéricos , Eficiencia Organizacional/estadística & datos numéricos , Investigación/estadística & datos numéricos , Academias e Institutos/economía , Academias e Institutos/legislación & jurisprudencia , Bibliometría , Estudios Transversales , Humanos , México , Investigación/economía , Investigación/legislación & jurisprudencia , Apoyo a la Investigación como Asunto , Estudios Retrospectivos , Seguridad Social , Evaluación de la Tecnología BiomédicaRESUMEN
Potyvirus HCPro is a multifunctional protein that, among other functions, interferes with antiviral defenses in plants and mediates viral transmission by aphid vectors. We have visualized in vivo the subcellular distribution and dynamics of HCPro from Potato virus Y and its homodimers, using green, yellow, and red fluorescent protein tags or their split parts, while assessing their biological activities. Confocal microscopy revealed a pattern of even distribution of fluorescence throughout the cytoplasm, common to all these modified HCPros, when transiently expressed in Nicotiana benthamiana epidermal cells in virus-free systems. However, in some cells, distinct additional patterns, specific to some constructs and influenced by environmental conditions, were observed: i) a small number of large, amorphous cytoplasm inclusions that contained α-tubulin; ii) a pattern of numerous small, similarly sized, dot-like inclusions distributing regularly throughout the cytoplasm and associated or anchored to the cortical endoplasmic reticulum and the microtubule (MT) cytoskeleton; and iii) a pattern that smoothly coated the MT. Furthermore, mixed and intermediate forms from the last two patterns were observed, suggesting dynamic transports between them. HCPro did not colocalize with actin filaments or the Golgi apparatus. Despite its association with MT, this network integrity was required neither for HCPro suppression of silencing in agropatch assays nor for its mediation of virus transmission by aphids.
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Áfidos/virología , Cisteína Endopeptidasas/metabolismo , Nicotiana/virología , Enfermedades de las Plantas/virología , Potyvirus/metabolismo , Proteínas Virales/metabolismo , Animales , Transporte Biológico , Cisteína Endopeptidasas/genética , Citoplasma/metabolismo , Citoplasma/ultraestructura , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/ultraestructura , Ambiente , Expresión Génica , Genes Reporteros , Cuerpos de Inclusión Viral/metabolismo , Cuerpos de Inclusión Viral/ultraestructura , Microtúbulos/metabolismo , Microtúbulos/ultraestructura , Epidermis de la Planta/ultraestructura , Epidermis de la Planta/virología , Hojas de la Planta/ultraestructura , Hojas de la Planta/virología , Potyvirus/genética , Potyvirus/ultraestructura , Proteínas Recombinantes de Fusión , Nicotiana/ultraestructura , Proteínas Virales/genéticaRESUMEN
BACKGROUND: Reduction of variability through process reengineering can improve surgical results for patients with type A acute aortic syndrome. We compare short-term results before and after implementation of an Aorta Code for patients with type A acute aortic syndrome who underwent surgery. METHODS: The Aorta Code was implemented in a 5-hospital healthcare network in 2019. This critical pathway was based on a simple diagnostic algorithm, ongoing training, immediate patient transfer, and treatment by an expert multidisciplinary team. We retrospectively compared all patients operated on in our center before (2005-2018) and after (January 2019 to February 2023) its implementation. RESULTS: One hundred two and 70 patients underwent surgery in the precode and code periods, respectively. In the code period the number of patients operated on per year increased (from 7.3 to 16.8), and the median elapsed time until diagnosis (6.5 hours vs 4.2 hours), transfer (4 hours vs 2.2 hours), and operating room (2.7 hours vs 1.8 hours) were significantly shorter (P < .05). Aortic root repair and total arch replacement were more frequent (66.7% vs 82.9% [P = .003] and 20.6% vs 40% [P = .001]). Cardiopulmonary bypass and ischemia times were also shorter (179.7 minutes vs 148.2 minutes [P = .001] and 105 minutes vs 91.2 minutes [P = .022]). Incidence of prolonged mechanical ventilation (53.9% vs 34.3%, P = .011), major stroke (17.7% vs 7.1%, P = .047), and 30-day mortality (27.5% vs 7.1%, P = .001) decreased significantly. CONCLUSIONS: An Aorta Code can be successfully implemented by using a standardized protocol within a hospital network. The number of cases increased; time to diagnosis, transfer, and operating room were reduced; and 30- day mortality significantly decreased.
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Sindrome Aortico Agudo , Disección Aórtica , Humanos , Estudios Retrospectivos , Aorta/cirugía , Disección Aórtica/diagnóstico , Disección Aórtica/cirugía , Puente Cardiopulmonar , Resultado del Tratamiento , Aorta Torácica/cirugíaRESUMEN
A sensitive and efficient solid-phase microextraction (SPME) method for the determination of organophosphorous (OPPs) and pyrethroid pesticides (Pyrs) in aquaculture-seawater samples by using GC with MS/MS (GC-MS/MS) was developed. Dichlorvos and chlorpyrifos (OPPs); permethrin, alpha-cypermethrin and deltamethrin (Pyrs) were selected according to their use as chemotherapeutants in the aquaculture industry. Different parameters affecting extraction efficiency such as fibre coating, agitation, pH and extraction time profiles were investigated. An experimental central composite design (alpha = 1) and desirability functions were used for the simultaneous optimization of extraction temperature and sample volume. Finally, a method based on direct SPME in 40 min at 75 degrees C using 100-microm-thick poly(dimethyl)siloxane (PDMS) fibre and 20 mL of sample volume is proposed. The method was validated, exhibiting good linearity, precision and accuracy parameters with picogram per millilitre LODs. The proposed methodology was applied to determine the ultratrace levels of OPPs and Pyrs in aquaculture-seawater samples by the standard addition approach, which proved to be reliable and sensitive, in addition to requiring only small amounts of sample.
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Antiprotozoarios/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Agua de Mar/química , Microextracción en Fase Sólida/métodos , Acuicultura , Cloropirifos/análisis , Diclorvos/análisis , Dimetilpolisiloxanos/química , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Concentración de Iones de Hidrógeno , Estructura Molecular , Nitrilos/análisis , Permetrina/análisis , Piretrinas/análisis , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Microextracción en Fase Sólida/instrumentación , Estereoisomerismo , Propiedades de Superficie , Temperatura , Factores de Tiempo , Contaminantes Químicos del Agua/análisisRESUMEN
Introducción: La calidad de la dieta se refiere a la composición nutricional y equilibrio de los alimentos consumidos, lo que puede influir en la salud y bienestar a largo plazo. El objetivo de este estudio fue evaluar la calidad de la dieta y el estado nutricional en estudiantes de una universidad pública de Paraguay. Materiales y métodos: Estudio transversal descriptivo realizado en estudiantes universitarios. Se recolectaron dos recordatorios de 24 horas en días no consecutivos, mediante metodología de pasos múltiples, para clasificar la calidad de la dieta (muy baja, baja, moderada, buena) de acuerdo con el índice de calidad de la dieta (DQI). Se tomaron medidas antropométricas (peso talla, circunferencia de cintura) y de composición corporal, para determinar el estado nutricional. Se utilizó estadística descriptiva y pruebas estadísticas como Chi2 y prueba exacta de Fisher. El protocolo fue aprobado por la Dirección de Investigaciones, UNA_FCM_DI N° 262/2021. Resultados: Participaron 39 estudiantes universitarios, de los cuales 31 eran mujeres. El 64,1% tenía menos de 25 años y 21 (53,8%) estaban en carreras de salud. Se observó que el 64,1% de los estudiantes tenían una baja o muy baja calidad de la dieta, el 33,3% una calidad moderada y el 2,6% una calidad buena. Además, 17 estudiantes presentaron exceso de peso (43,6%) y 19 se encontraban en normopeso (48,7%). Se destacó que el 68,2% de los estudiantes sin exceso de peso tenían una dieta de baja o muy baja calidad. Conclusión: Los estudiantes universitarios evaluados en este estudio presentaron baja calidad de la dieta y desequilibrio en el aporte de macronutrientes. A pesar de esto, el estado nutricional más frecuente fue el normopeso. Se destaca la importancia de promover intervenciones para mejorar la calidad de la dieta y fomentar hábitos saludables en esta población.
Introduction: Diet quality refers to the nutritional composition and balance of the consumed foods, which can influence health and well-being in the long term. This study aimed to evaluate the diet quality and nutritional status among students at a public university in Paraguay. Materials and methods: A descriptive cross-sectional study was conducted among university students. Two 24-hour recalls were collected on non-consecutive days, using the multi-step methodology, to classify diet quality (very low, low, moderate, good) according to the Diet Quality Index (DQI). Anthropometric measurements (weight, height, waist circumference) and body composition were taken to determine the nutritional status. Descriptive statistics and statistical tests such as Chi2 and Fisher's exact test were used. The protocol was verified by the Research Directorate, UNA_FCM_DI N° 262/2021. Results: 39 university students participated, of which 31 were females. 64,1% were under 25 years old and 21 (53,8%) were enrolled in health-related careers. It was observed that 64,1% of the students had poor or very poor diet quality, 33,3% had moderate quality and 2.6% a good quality. Additionally, 17 students were overweight (43,6%) and 19 were within the normal weight range (48,7%). It was highlighted that 68,2% of the students with no excess weight had a diet of poor or very poor quality. Conclusion: The university students evaluated in this study presented poor diet quality and imbalance in macronutrients intake. Despite this, the most frequent nutritional status was within the normal weight range. The importance of promoting interventions to improve diet quality and promote healthy habits in this population is highlighted.
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The enzyme-linked immunosorbent assay (ELISA) technique is based on the specific recognition ability of the molecular structure of an antigen (epitope) by an antibody and is likely the most important diagnostic technique used today in bioscience. With this methodology, it is possible to diagnose illness, allergies, alimentary fraud, and even to detect small molecules such as toxins, pesticides, heavy metals, etc. For this reason, any procedures that improve the detection limit, sensitivity or reduce the analysis time could have an important impact in several fields. In this respect, many methods have been developed for improving the technique, ranging from fluorescence substrates to methods for increasing the number of enzyme molecules involved in the detection such as the biotin-streptavidin method. In this context, nanotechnology has offered a significant number of proposed solutions, mainly based on the functionalization of nanoparticles from gold to carbon which could be used as antibody carriers as well as reporter enzymes like peroxidase. However, few works have focused on the study of best practices for nanoparticle functionalization for ELISA enhancement. In this work, we use 20 nm gold nanoparticles (AuNPs) as a vehicle for secondary antibodies and peroxidase (HRP). The design of experiments technique (DOE) and four different methods for biomolecule loading were compared using a rabbit IgG/goat anti-rabbit IgG ELISA model (adsorption, directional, covalent and a combination thereof). As a result, AuNP probes prepared by direct adsorption were the most effective method. AuNPs probes were then used to detect gliadin, one of the main components of wheat gluten, the protein composite that causes celiac disease. With this optimized approach, our data showed a sensitivity increase of at least five times and a lower detection limit with respect to a standard ELISA of at least three times. Additionally, the assay time was remarkably decreased.
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La formación investigativa es un proceso continuo donde se desarrollan habilidades, capacidades y valores de la actividad científica, tanto en el pregrado como en el postgrado, que van a permitir actuar en la práctica y transformarla. Es un componente básico en la preparación profesional del médico; su naturaleza es sistémica y se ha realizado por dos vías fundamentales: la sustentada en la práctica y la que se realiza a partir de cursos y actividades académicas planificadas, como son los programas de formación doctoral. Constituye una necesidad acceder al conocimiento científico acumulado en las tesis doctorales, no solo con vistas a encontrar nuevas vías de solución a problemas de la práctica médica actual, también, las deficiencias teórico metodológicas pudieran ser enriquecedoras al proceso educativo en cuanto a la formación científica de los educandos. Pero, muchos son los retos a los que se enfrenta hoy la formación investigativa de los profesionales de la salud en el pregrado y el postgrado. Mirarla desde el punto más alto de su formación, la formación doctoral, constituye motivo de reflexión en esta contribución científica(AU)
Research training is a continuous process where skills, capacities and values ââof scientific activity are developed, both at undergraduate and postgraduate level, which will allow acting in practice and transform it. It is a basic component in the professional preparation of the doctor, its nature is systemic and has been carried out in two fundamental ways: the one supported in practice and the one that is carried out from courses and planned academic activities, such as doctoral training programs. It is a necessity to access the scientific knowledge accumulated in the doctoral theses, not only with a view to finding new ways of solving problems of current medical practice, also, theoretical methodological deficiencies, could be enriching to the educational process in terms of scientific training of the students. But, there are many challenges facing the research training of health professionals in the undergraduate and postgraduate programs. Looking at it from the highest point of its formation, doctoral training, is a reason for reflection in this scientific contribution(AU)
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Humanos , Salud , Conocimiento , Preparación ante Desastres , Cursos , TutoríaRESUMEN
Enrofloxacin (ERFX) is a synthetic antibiotic of the fluoroquinolone (FQ) family, which is commonly administered in veterinary medicine. ERFX and its metabolite, ciprofloxacin (CPFX), have been reported to accumulate in hair of treated animals. Therefore, hair analysis is an attractive non-invasive alternative to control misuse of such antibiotic and to ensure food safety by preventing such food derived products arrive to the consumer. In this context, an immunochemical analytical protocol has been established to detect ERFX and CPFX residues in cattle hair samples. Unpigmented and pigmented hair were collected from ERFX-treated and non-treated calves, and the aqueous NH4OH extracts were directly analyzed by ELISA, being possible to achieve limits of detection in the range of 10-30 µg kg(-1). A good concordance between HPLC and ELISA measurements was observed. The results demonstrate the potential of the immunochemical procedure reported here to rapidly screen and quantitate FQ residues in hair samples.
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Antibacterianos/química , Fluoroquinolonas/química , Cabello/química , Animales , Bovinos , Inocuidad de los Alimentos , InmunoquímicaRESUMEN
In the Potyvirus genus, the P1 protein is the first N-terminal product processed from the viral polyprotein, followed by the helper-component proteinase (HCPro). In silencing suppression patch assays, we found that Potato virus Y (PVY) HCPro expressed from a P1-HCPro sequence increased the accumulation of a reporter gene, whereas protein expressed from an HCPro sequence did not, even with P1 supplied in trans. This enhancing effect of P1 has been noted in other potyviruses, but has remained unexplained. We analysed the accumulation of PVY HCPro in infiltrated tissues and found that it was higher when expressed from P1-HCPro than from HCPro sequences. Co-expression of heterologous suppressors increased the steady-state level of mRNA expressed from the HCPro sequence, but not that of protein. This suggests that, in the absence of P1 upstream, either HCPro acquires a conformation that affects negatively its activity or stability, or that its translation is reduced. To test these options, we purified HCPro expressed in the presence or absence of upstream P1, and found no difference in purification pattern and final soluble state. By contrast, alteration of the Kozak context in the HCProâ mRNA sequence to favour translation increased partially suppressor accumulation and activity. Furthermore, protein activity was not lower than in protein expressed from P1-HCPro sequences. Thus, a direct role for P1 on HCPro suppressor activity or stability, by influencing its conformation during translation, can be excluded. However, P1 could still have an indirect effect favouring HCPro accumulation. Our data highlight the relevance of cis-acting translational elements in the heterologous expression of HCPro.
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Cisteína Endopeptidasas/metabolismo , Silenciador del Gen , Potyvirus/metabolismo , Biosíntesis de Proteínas , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/aislamiento & purificación , Genes Supresores , Datos de Secuencia Molecular , Potyvirus/genética , Solubilidad , Supresión Genética , Nicotiana/virología , Proteínas Virales/química , Proteínas Virales/aislamiento & purificaciónRESUMEN
An exhaustive study is reported on the effect that antibody nanogold probes produce on the performance of a Surface Plasmon Resonance (SPR) immunosensor. The paper studies the improvement that different nanogold probes prepared at different antibody:gold nanoparticle (IgG:AuNP) ratios and AuNP sizes produce on the maximum signal and detectability of a simple SPR immunosensor developed to analyze fluoroquinolone (FQ) antibiotic residues (SPReeta system). The investigation compares the features of sensor enhanced formats using both, secondary and primary nanogold probes (anti-IgG and IgG coupled to AuNP, on double and single-antibody immunochemical assay steps, respectively), in respect to the unenhanced format. For this purpose, a reproducible bioconjugation procedure for preparing gold biohybrid nanoparticles has been established, involving the formation of a mixed self-assembled monolayer (m-SAM) with PEGylated cross-linkers around the AuNP followed by the covalent attachment of the antibodies. The procedure allows controlling the IgG:AuNP ratio of the nanogold probes on a reproducible manner and the functionalized NPs have been found to be stable during assay and storage. Both formats, using secondary and primary nanogold probes, are excellent strategies to improve immunosensor detectability. Thus, using anti-IgG-AuNP, the detectability could be improved by a factor of 14 (LOD 0.07±0.01 µg L(-1) vs. 0.98±0.38 µg L(-1)) reducing at the same time the amount of primary antibody used (30,000 vs. 1000 dilution factor). Likewise, the format using IgG-AuNP also allows improving detectability (LOD 0.11±0.01 µg L(-1)), but reducing the number of needed steps.
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Antibacterianos/aislamiento & purificación , Técnicas Biosensibles/métodos , Oro/química , Inmunoglobulina G/química , Resonancia por Plasmón de Superficie/métodos , Anticuerpos Antiidiotipos/química , Fluoroquinolonas/química , Humanos , Inmunoensayo/métodos , Nanopartículas/químicaRESUMEN
This paper reports the development of an immunoassay for the specific analysis of doxycycline (DC), a congener of the tetracycline antibiotic family (TCs), in milk samples. This is the first time that DC antibody production is reported, based on a rationally designed and well-characterized immunizing hapten. The chemical structure of the immunizing hapten (13-[(2-carboxyethyl)thiol]-5-hydroxy-6-α-deoxytetracycline, TC1) was designed to maximize recognition of the tetracycline characteristic moiety defined as lower periphery of the TCs plus the region of the upper periphery composed by the hydroxyl group at position C(5) (B ring) and the dimethylamino group in ring A. Polyclonal antibodies raised against TC1 coupled to horseshoe crab hemocianyn (HCH) were used to develop a homologous indirect competitive enzyme-linked immunosorbent assay (ELISA). The microplate ELISA can detect DC in buffer down to 0.1 µg L(-1). The ELISA has been proven to tolerate a wide range of ionic strengths and pH values. The assay is very selective for DC with a minor recognition of methacycline (32% of cross-reactivity). Experiments performed with whole milk samples demonstrate that samples can be directly analyzed after a simple treatment method, reaching detectability values below 5 µg L(-1).
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Antibacterianos/análisis , Doxiciclina/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Leche/química , Animales , Antibacterianos/inmunología , Anticuerpos/análisis , Anticuerpos/inmunología , Bovinos , Doxiciclina/inmunología , Femenino , Contaminación de Alimentos/análisis , ConejosRESUMEN
An inexpensive and portable surface plasmon resonance (SPR) sensor, SPReeta Evaluation Kit SPR3, has been used to develop a biosensor for the determination of fluoroquinolone antibiotics (FQs) and to demonstrate its performance analyzing FQ residues in milk samples. The SPReeta three-channel gold chips were activated with a mixed self-assembled monolayer (m-SAM) and functionalized with a FQ haptenized protein. Binding of the antibody produced a concentration-dependent increase of the SPR signal as a result of the change in the refraction index. Similarly, the presence of the FQ produced a dose-dependent decrease of the response, which allowed a good limit of detection (LOD) to be obtained (1.0 ± 0.4 µg L(-1) for enrofloxacin in buffer). The response was reproducible in all three channels, on different injections and days, and also between chips. Milk samples could be analyzed after a simple sample treatment involving fat removal by centrifugation and dilution with water. Under these conditions calibration curves were obtained showing that FQ residues can be analyzed in milk samples with an IC(50) value of 26.4 ± 7.2 µg L(-1) and a LOD of 2.0 ± 0.2 µg L(-1) (for enrofloxacin), far below the European Union regulations for this antibiotic family in this matrix. Finally, the paper also demonstrates that the biosensor is able to selectively detect the presence of FQs in milk samples, even in the presence of other antibiotics. Enrofloxacin, ciprofloxacin, and norfloxacin residues were detected in blind samples supplied by Nestlé Co.
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Antibacterianos/análisis , Técnicas Biosensibles/métodos , Residuos de Medicamentos/análisis , Fluoroquinolonas/análisis , Leche/química , Resonancia por Plasmón de Superficie/métodos , Animales , Técnicas Biosensibles/instrumentación , Bovinos , Resonancia por Plasmón de Superficie/instrumentaciónRESUMEN
OBJECTIVE: To present clinical cases of women who had an accessory and cavitated noncommunicating uterine mass with functioning endometrium associated with a normal uterus, suggestive of a new type of Müllerian anomaly. METHODS: We report on five institutional cases: four cases of cavitated accessory uterine mass and a case of true adenomyoma. A review of the literature was performed by looking for these terms and others related in MEDLINE. RESULTS: Including ours, there are 18 cases in the literature showing an accessory cystic cavity lined by endometrioid epithelium with an otherwise normal uterus. Another 11 cases only partially fulfilled the inclusion criteria. All of the first cases were in young women presenting with severe dysmenorrhea (n=4). Generally, the tumor was located in the anterior wall of the uterus at the level of insertion of the round ligament. It presents a certain similarity with the cavitated true adenomyomas observed in older women in whom the endometrial lining of the cystic cavity is generally absent. For differential diagnosis with cavitated noncommunicating rudimentary uterine horns, hysterosalpingography showing a normal eutopic uterine cavity is decisive. CONCLUSION: Noncommunicating accessory uterine cavities and isolated cystic adenomyomas correspond to the same pathology: cavitated accessory uterine mass associated with an otherwise normal uterus. They present problems of differential diagnosis with true cavitated adenomyomas and cavitated rudimentary uterine horns. Accessory uterine mass could be caused by duplication and persistence of ductal Müllerian tissue in a critical area at the attachment level of the round ligament, possibly related to a gubernaculum dysfunction. LEVEL OF EVIDENCE: III.