Search results for "Microscopy"
showing 10 items of 3390 documents
Structural Studies Reveal that Endosomal Cations Promote Formation of Infectious Coxsackievirus A9 A-Particles, Facilitating RNA and VP4 Release
2022
Coxsackievirus A9 (CVA9), an enterovirus, is a common cause of pediatric aseptic meningitis and neonatal sepsis. During cell entry, enterovirus capsids undergo conformational changes leading to expansion, formation of large pores, externalization of VP1 N termini, and loss of the lipid factor from VP1. Factors such as receptor binding, heat, and acidic pH can trigger capsid expansion in some enteroviruses. Here, we show that fatty acid-free bovine serum albumin or neutral endosomal ionic conditions can independently prime CVA9 for expansion and genome release. Our results showed that CVA9 treatment with albumin or endosomal ions generated a heterogeneous population of virions, which could b…
Compact Cell Imaging Device (CoCID) provides insights into the cellular origins of viral infections
2021
The overall CoCID concept is centred on providing virologists with a next-generation imaging device, which, through increased penetration and depth of focus, as well as through high natural contrast and sensitivity to organelle density (including virus-related organelles), will produce higher-fidelity ultrastructural images of whole intact cells. These insights will, in turn, help increase our understanding of the links between the structural reorganisation of cells and the mechanisms of viral entry, replication, assembly, and egress in cells. CoCID will provide this valuable imaging capability in the form of a compact lab-scale device that will greatly improve the accessibility of soft X-r…
Synthesis, antiproliferative activity and possible mechanism of action of novel 2-acetamidobenzamides bearing the 2-phenoxy functionality.
2015
Several new 2-(2-phenoxyacetamido)benzamides 17a-v, 21 and 22 were synthesized by stirring in pyridine the acid chlorides 16a-e and the appropriate5-R-4-R1-2-aminobenzamide 15a-e and initially evaluated in vitro for antiproliferative activity against the K562 (human chronic myelogenous leukemia) cell line. Some of synthesized compounds were evaluated for their in vitro antiproliferative activity against the full NCI tumor cell line panel derived from nine clinically isolated cancer types (leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate and breast). The most active compounds caused an arrest of K562 cells in the G0-G1 phase of cell cycle and induction of apoptos…
A Guide to Perform 3D Histology of Biological Tissues with Fluorescence Microscopy
2023
The analysis of histological alterations in all types of tissue is of primary importance in pathology for highly accurate and robust diagnosis. Recent advances in tissue clearing and fluorescence microscopy made the study of the anatomy of biological tissue possible in three dimensions. The combination of these techniques with classical hematoxylin and eosin (H&E) staining has led to the birth of three-dimensional (3D) histology. Here, we present an overview of the state-of-the-art methods, highlighting the optimal combinations of different clearing methods and advanced fluorescence microscopy techniques for the investigation of all types of biological tissues. We employed fluorescence …
Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy
2021
As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original …
Live imaging of developmental processes in a living meristem of Davidia involucrata (Nyssaceae)
2014
Morphogenesis in plants is usually reconstructed by scanning electron microscopy and histology of meristematic structures. These techniques are destructive and require many samples to obtain a consecutive series of states. Unfortunately, using this methodology the absolute timing of growth and complete relative initiation of organs remain obscure. To overcome this limitation, an in vivo observational method based on Epi-Illumination Light Microscopy (ELM) was developed and tested with a male inflorescence meristem (floral unit) of the handkerchief tree Davidia involucrata Baill. (Nyssaceae). We asked whether the most basal flowers of this floral unit arise in a basipetal sequence or, altern…
Semilunar Granule Cells Are the Primary Source of the Perisomatic Excitatory Innervation onto Parvalbumin-Expressing Interneurons in the Dentate Gyrus
2020
AbstractWe analyzed the origin and relevance of the perisomatic excitatory inputs on the parvalbumin interneurons of the granule cell layer in mouse. Confocal analysis of the glutamatergic innervation showed that it represents ∼50% of the perisomatic synapses that parvalbumin cells receive. This excitatory input may originate from granule cell collaterals, the mossy cells, or even supramammillary nucleus. First, we assessed the input from the mossy cells on parvalbumin interneurons. Axon terminals of mossy cells were visualized by their calretinin content. Using multicolor confocal microscopy, we observed that less than 10% of perisomatic excitatory innervation of parvalbumin cells could or…
Development of polypeptide-based therapeutics for the treatment of castration resistant prostate cancer
2019
El cáncer de próstata (CaP) es el segundo cáncer más frecuente en los hombres. Los estudios han establecido el gen de fusión (T2E) compuesto por TMPRSS2 (serina proteasa dependiente de andrógenos) y ERG (factor de transcripción de la familia ETS) como un biomarcador potencial de CaP. La progresión en el CaP incluye tanto el receptor de andrógenos (AR) como el receptor del factor de crecimiento de insulina 1 (IGF-1R), y el tratamiento con un anticuerpo anti-IGF-1R (AVE1642) ha demostrado un gran potencial en el tratamiento de los pacientes con CaP T2E-positivos. Por ello, el desarrollo de terapias personalizadas basadas en polímeros terapéuticos puede favorecer el tratamiento de CaP para un …
Spatially multiplexed interferometric microscopy: from basic principles to advanced arrangements
2019
La posibilidad de visualizar y analizar objetos microscópicos transparentes de una manera no invasiva ha sido uno de los principales retos de la microscopía óptica a lo largo del siglo XX. Para ello, se desarrollaron diversas técnicas de microscopía que convertían las variaciones en el índice de refracción de los objetos en variaciones de intensidad, haciendo estos objetos visibles a simple vista, entre las que destacan la microscopía de contraste de fase de Zernike o de contraste diferencial de Nomarski. Sin embargo, estas técnicas solamente proporcionan información cualitativa del objeto, por lo que su análisis se limita a la simple visualización. Por otro lado, existen otras técnicas de …
Decorated pottery study: Analysis of pigments by x-ray absorbance spectroscopy measurements
2007
Characterization of pigments on decorated pottery fragments has been fully carried out by nondestructive x-ray absorbance spectroscopy (XAS). The samples were a series of pottery shards excavated from the archeological site of Caltagirone (Sicily, Italy), a well-known ceramic production center. Aesthetical criteria and morphological observations allowed us to attribute the samples to quite different historical periods, starting from the 18th century B.C. up to the 16th century A.D. An extensive time interval led us to suppose that different materials and techniques were used for the production of the ceramic paste and also for the preparation of pigments. XAS measurements were performed at …