On-line surface plasmon resonance biosensing of vascular endothelial growth factor signaling in intact-human hepatoma cell lines

Surface plasmon resonance (SPR) monitoring of biorecognition events at intracellular levels is a valuable tool for studying the angiogenic response of carcinoma living cells during tumor growth and proliferation. We report here a comparative study of two different strategies to detect human hepatoma cell interactions between transmembrane vascular endothelial growth factor receptor (VEGFR2) and vascular endothelial growth factor (VEGF). To monitor VEGFR2 activation after VEGF stimulation, intact hepatocellular carcinoma HepG2 or Huh7 cells (2 × 105 cells per mL) were directly immobilized on the sensor chip. Distinguishable SPR sensorgrams were obtained for each cell line depending on the time required for VEGFR2 activation. SPR signals for VEGF-VEGFR2 binding were inhibited by the VEGFR inhibitor, CBO-P11. The SPR response after VEGF stimulation/inhibition was in good agreement with the results observed by immunoblotting analysis. In a second approach we used intact cell lines as analytes. SPR analysis was done by injecting HepG2 and HuH7 cell suspensions (2-4 × 104 cells per mL) onto a sensor surface previously immobilized with VEGF via a thiol self-assembled monolayer (SAM). Specificity and reproducibility were evaluated reusing the same chip surface over more than 60 complete regeneration cycles. Comparison between both methods yielded differences in terms of reliability, making the latter strategy more effective for the analysis of real samples. The investigation of VEGF signaling in intact human hepatoma living cells by SPR monitoring comprises a novel and promising design for the study of tumor angiogenesis via downregulation of VEGF and VEGFR2 pathways. Further investigation on VEGFR activation and vascular function could contribute to establish a robust and meaningful tool for early cancer diagnostics.CIBERehd and CIBER-BBN are funded by Instituto de Salud Carlos III (Spain). Sara Carbajo-Pescador is supported by the Consejería de Educación (Junta de Castilla y León, Spain) and Fondo Social Europeo. Raquel Ordoñez is supported by the program Formación del Profesorado Universitario from the Ministry of Education (Spain). This work has been partially supported by Fundación Investigación Sanitaria en León.Peer Reviewe

Is the sound environment relevant for how people use common spaces?

\u3cp\u3eRapid and intrusive spatial adjustments in common spaces are increasingly questioned by the awareness of citizens demanding higher quality standards. This study aims to understand the use of common space by identifying how the sound environment affects the functions of space and the interaction with other environmental and spatial variables. Is there a certain sound environment required or that should be avoided when designing a space for a specific activity? In situ evaluations with regular users were collected in nine common spaces in Gothenburg, Sweden, conducting sound recordings and questionnaires. Site selection responded to the purpose of the analysed places, the noise level (LAeq) of the city road traffic noise map, and the number of activities suggested by the city sociotope maps. The analyses revealed that certain activities could be identified from LAeq values. Discriminant functions with respect to sound levels primarily identified a tranquil/restorative vibrant dimension, where the highest noise levels tend to be at the most vibrant end. Other results showed that a considerable variability of overall and visual quality judgements came from the variability in sites. These quality assessments were highly correlated, allowing both to be analysed as a single attribute. The variability in sound quality was much lower. Notable is the difference between recorded and perceived loudness. In addition, poor sound quality judgement does not seem to correlate with the perception of mechanical sources as the main source of noise.\u3c/p\u3

Towards the design of universal immunosurfaces for SPR-based assays: A review

Surface biofunctionalization, including chemical activation and attachment of the bioreceptor, is an essential step to provide reliable detection of biomolecular binding events monitored by Surface Plasmon Resonance (SPR), the most employed optical biosensor, and other biosensor techniques. Recent progress in the area of immobilization procedures are aimed at producing reproducible interfacial surfaces that enable the sensitive and specific recognition of the analyte. Antibodies are still the most employed bioreceptors for SPR assays. A wide range of strategies have been proposed to maximize the SPR immunosensor performance by controlling the stability and orientation of the immobilized antibody. This article reviews the most recent advancements in random and oriented antibody immobilization approaches for SPR biosensing applications, with a special focus on the research that have been done to find universal linkers, which can allow the use of the same functionalized surface for different applications.The nanoB2A is a consolidated research group (Grup de Recerca) of the Generalitat de Catalunya and has support from the Departament d'Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya (2014 SGR 624). ICN2 is the recipient of Grant SEV-2013-0295 from the “Severo Ochoa Centers of Excellence” Program of Spanish MINECO.Peer Reviewe

Is the sound environment relevant for how people use common spaces?

Rapid and intrusive spatial adjustments in common spaces are increasingly questioned by the awareness of citizens demanding higher quality standards. This study aims to understand the use of common space by identifying how the sound environment affects the functions of space and the interaction with other environmental and spatial variables. Is there a certain sound environment required or that should be avoided when designing a space for a specific activity? In situ evaluations with regular users were collected in nine common spaces in Gothenburg, Sweden, conducting sound recordings and questionnaires. Site selection responded to the purpose of the analysed places, the noise level (LAeq) of the city road traffic noise map, and the number of activities suggested by the city sociotope maps. The analyses revealed that certain activities could be identified from LAeq values. Discriminant functions with respect to sound levels primarily identified a tranquil/restorative vibrant dimension, where the highest noise levels tend to be at the most vibrant end. Other results showed that a considerable variability of overall and visual quality judgements came from the variability in sites. These quality assessments were highly correlated, allowing both to be analysed as a single attribute. The variability in sound quality was much lower. Notable is the difference between recorded and perceived loudness. In addition, poor sound quality judgement does not seem to correlate with the perception of mechanical sources as the main source of noise

Effect of melatonin supplementation on food and water intake in streptozotocin-diabetic and non-diabetic male Wistar rats Efecto de la suplementación oral con melatonina sobre la ingestión de agua y alimento en ratas Wistar macho con diabetes experimental

The effect of orally supplemented melatonin (MT) at 1 mg/kg bw for 4 weeks on feeding behavior of non-diabetic and diabetic male Wistar rats has been studied by computerized meal pattern analysis. Exogenous MT has a satiating effect in non-diabetic rats, but not in diabetic animals. The changes in feeding behavior induced by MT in non-diabetic animals are related to changes in meal frequency, size and duration leading to lower total food intake during the scotophase. MT administration to diabetic rats resulted in lower drinking time and higher faecal output, without further behavioral effects. We conclude that the notorious metabolic changes ocurring in the streptozotocin-diabetic rat can overcome most of the underlying effects of MT supplementation. The possible MT usage for therapeutical purposes could benefit from the lack of behavioral alterations in diabetic animals.Varias líneas de evidencia señalan a la melatonina (MT) como un importante factor en el complejo entramado de la regulación de la ingestión de alimento. Puesto que la secreción de MT aumenta en la rata con diabetes tipo I, y dada la importancia de MT en el tracto gastrointestinal, es interesante comprobar los efectos de MT sobre el alterado comportamiento ingestivo de estos animales. Se ha estudiado el efecto de la suplementación oral de MT (1 mg por kg de peso corporal y día) en la escotofase sobre el comportamiento ingestivo de ratas Wistar macho diabéticas y no diabéticas durante cuatro semanas mediante análisis de pautas de ingestión asistido por ordenador. La administración de MT exógena indujo un efecto de saciación en ratas no diabéticas, pero no en animales diabéticos. Los cambios en comportamiento ingestivo inducidos por MT en animales no diabéticos están relacionados con cambios en frecuencia, tamaño y duración de las comidas, con el resultado de una disminución de la ingestión total de alimento durante la escotofase. La administración de MT en ratas diabéticas originó una disminución del tiempo total de actividad dípsica y aumento de la masa fecal durante la escotofase, sin otros cambios comportamentales significativos. Se concluye que los notables cambios metabólicos que tienen lugar en la rata con diabetes experimental inducida por estreptozotocina provocan cambios comportamentales más potentes que los ejercidos por la suplementación oral con MT. El posible uso terapéutico de MT podría beneficiarse de la falta de alteraciones comportamentales en animales diabéticos