RESUMEN
In this manuscript we review work of our group on the assembly of lipid layers on top of polyelectrolyte multilayers (PEMs). The assembly of lipid layers with zwitterionic and charged lipids on PEMs is studied as a function of lipid and polyelectrolyte composition by the Quartz Crystal Microbalance. Polyelectrolyte lipid interactions are studied by means of Atomic Force Spectroscopy. We also show the coating of lipid layers for engineering different nanomaterials, i.e., carbon nanotubes and poly(lactic-co-glycolic) nanoparticles and how these can be used to decrease in vitro toxicity and to direct the intracellular localization of nanomaterials.
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Ingeniería , Ácido Láctico/química , Membrana Dobles de Lípidos/química , Nanopartículas/química , Nanotecnología , Nanotubos de Carbono/química , Ácido Poliglicólico/química , Transporte Biológico , Células Hep G2 , Humanos , Espacio Intracelular/metabolismo , Membrana Dobles de Lípidos/metabolismo , Modelos Moleculares , Conformación Molecular , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Tecnicas de Microbalanza del Cristal de Cuarzo , Propiedades de SuperficieRESUMEN
INTRODUCTION: Lack of habituation is the most reproducible interictal neurophysiological phenomenon in episodic migraine. The aim of this study is to evaluate the habituation phenomenon by examining the nociceptive blink reflex in patients with episodic migraine. SUBJECTS AND METHODS: We conducted a cross-sectional observational case-control study. Patients with episodic migraine were selected consecutively and studied during the interictal phase. The nociceptive blink reflex was examined and a study was conducted comparing symmetry, analysis of the Euclidean distances and assessment of latency prolongation between stimulation blocks. RESULTS: Thirty-one patients and 16 healthy controls were included, their mean ages being 32.25 and 32.35 years, respectively. The controls displayed left-right symmetry. The Euclidean and Manhattan distances showed that the means of the block latencies of the groups are different and increase according to the number of blocks being compared. The means of the block latencies do not differ significantly in the migraine patient group, in contrast to what is seen in the healthy group. CONCLUSION: Habituation deficit was observed in the interictal phase in patients with episodic migraine compared to controls, as measured by the absence of latency prolongation in the nociceptive blink reflex.
TITLE: Estudio del déficit de habituación en pacientes con migraña episódica mediante reflejo de parpadeo nociceptivo.Introducción. La falta de habituación es el fenómeno neurofisiológico interictal más reproducible en la migraña episódica. El objetivo de este estudio es evaluar el fenómeno de habituación mediante el estudio del reflejo de parpadeo nociceptivo en pacientes con migraña episódica. Sujetos y métodos. Estudio observacional transversal de casos y controles. Los pacientes con migraña episódica fueron seleccionados de manera consecutiva, estudiados durante la fase interictal. Se estudió el reflejo de parpadeo nociceptivo, y se realizó un estudio comparativo de simetría, análisis de distancias euclidianas y valoración de prolongación de latencias entre bloques de estimulación. Resultados. Se incluyó a 31 pacientes y 16 controles sanos, con una edad media de 32,25 y 32,35 años, respectivamente. Los controles mostraron simetría izquierda-derecha. Las distancias euclidiana y Manhattan demostraron que las medias de las latencias por bloque de los grupos son diferentes y se incrementan según el número de bloques que se comparen. Las medias de las latencias de los bloques no difieren significativamente en el grupo de pacientes con migraña, a diferencia del grupo de sanos. Conclusión. Se observó un déficit de habituación en la fase intercrítica en pacientes con migraña episódica frente a controles, medido por la ausencia de prolongación de latencias en el reflejo de parpadeo nociceptivo.
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Parpadeo , Trastornos Migrañosos , Adulto , Humanos , Estudios de Casos y Controles , Estudios Transversales , Habituación Psicofisiológica , NocicepciónRESUMEN
Norovirus-like particles were imaged using atomic force microscopy. The mechanical stability of the virus-like particles (VLPs) was probed by nanoindentation at pH values ranging from 2 to 10. This range includes pH values of the natural environment during the life cycle of noroviruses. The resistance of VLPs to indentation was constant at acidic and neutral pH. The Young's modulus was of the order of 30â MPa. At basic pH the compliance of the capsid increased along with an increase in diameter. This specific pH-dependent mechanical response of the capsid may be related to mechanisms controlling uptake and release of the RNA during infection. Consecutive indentations with pressures ≤ 300â bar demonstrated the ability of the capsids to fully recover from deformations comparable with the size of the capsid. The capsids can be viewed as nanocontainers with an inbuilt self-repair mechanism. At pH 10 the capsids lost their stability and were irreversibly destroyed after one single indentation.