Search results for "Microscopy"
showing 10 items of 3390 documents
In Vivo Imaging of Partially Reversible Th17 Cell-Induced Neuronal Dysfunction in the Course of Encephalomyelitis
2010
SummaryNeuronal damage in autoimmune neuroinflammation is the correlate for long-term disability in multiple sclerosis (MS) patients. Here, we investigated the role of immune cells in neuronal damage processes in animal models of MS by monitoring experimental autoimmune encephalomyelitis (EAE) by using two-photon microscopy of living anaesthetized mice. In the brainstem, we detected sustained interaction between immune and neuronal cells, particularly during disease peak. Direct interaction of myelin oligodendrocyte glycoprotein (MOG)-specific Th17 and neuronal cells in demyelinating lesions was associated with extensive axonal damage. By combining confocal, electron, and intravital microsc…
Lafora disease fibroblasts exemplify the molecular interdependence between thioredoxin 1 and the proteasome in mammalian cells
2013
13 páginas, 8 figuras (que no aparecen en este documento, se pueden consultar en: http://www.sciencedirect.com/science/article/pii/S0891584913003274#ec0005)
Quantitative characterization of tetraspanin 8 homointeractions in the plasma membrane
2021
The spatial distribution of proteins in cell membranes is crucial for signal transduction, cell communication and membrane trafficking. Members of the Tetraspanin family organize functional protein clusters within the plasma membrane into so-called Tetraspanin-enriched microdomains (TEMs). Direct interactions between Tetraspanins are believed to be important for this organization. However, studies thus far have utilized mainly co-immunoprecipitation methods that cannot distinguish between direct and indirect, through common partners, interactions. Here we study Tetraspanin 8 homointeractions in living cells via quantitative fluorescence microscopy. We demonstrate that Tetraspanin 8 exists i…
Streptomyces coelicolor Vesicles: Many Molecules To Be Delivered
2022
ABSTRACT Streptomyces coelicolor is a model organism for the study of Streptomyces, a genus of Gram-positive bacteria that undergoes a complex life cycle and produces a broad repertoire of bioactive metabolites and extracellular enzymes. This study investigated the production and characterization of membrane vesicles (MVs) in liquid cultures of S. coelicolor M145 from a structural and biochemical point of view; this was achieved by combining microscopic, physical and -omics analyses. Two main populations of MVs, with different sizes and cargos, were isolated and purified. S. coelicolor MV cargo was determined to be complex, containing different kinds of proteins and metabolites. In particul…
Pyridinedicarboxylates, the first mechanism-derived inhibitors for prolyl 4-hydroxylase, selectively suppress cellular hydroxyprolyl biosynthesis. De…
1987
Two pyridinedicarboxylates, predicted [Hanauske-Abel (1983) M.D.-Ph.D. Thesis, Philipps Universität Marburg] and later found to be potent reversible inhibitors of purified prolyl 4-hydroxylase [Majaama, Hanauske-Abel, Günzler & Kivirikko (1984) Eur. J. Biochem. 138, 239-245] were investigated with respect to their effect on hydroxyprolyl biosynthesis in the fibroblast/collagen and the macrophage/Clq systems, and the effect was compared with that of the iron chelator 2,2′-dipyridyl, the compound usually employed to inhibit cellular hydroxyprolyl formation. Only the enzyme-mechanism-derived pyridinedicarboxylates were highly selective inhibitors, and only they lacked overt cytotoxicity. M…
Synthesis, spectroscopic studies and biological evaluation of acridine derivatives: The role of aggregation on the photodynamic efficiency.
2018
Two new photoactive compounds (1 and 2) derived from the 9-amidoacridine chromophore have been synthesized and fully characterized. Their abilities to produce singlet oxygen upon irradiation have been compared. The synthesized compounds show very different self-aggregating properties since only 1 present a strong tendency to aggregate in water. Biological assays were conducted with two cell types: hepatoma cells (Hep3B) and human umbilical vein endothelial cells (HUVEC). Photodynamic therapy (PDT) studies carried out with Hep3B cells showed that non-aggregating compound 2 showed photoxicity, ascribed to the production of singlet oxygen, being aggregating compound 1 photochemically inactive.…
Predetermined embryonic glial cells form the distinct glial sheaths of the Drosophila peripheral nervous system
2013
International audience; One of the numerous functions of glial cells in Drosophila is the ensheathment of neurons to isolate them from the potassium-rich haemolymph, thereby establishing the blood-brain barrier. Peripheral nerves of flies are surrounded by three distinct glial cell types. Although all embryonic peripheral glia (ePG) have been identified on a single-cell level, their contribution to the three glial sheaths is not known. We used the Flybow system to label and identify each individual ePG in the living embryo and followed them into third instar larva. We demonstrate that all ePG persist until the end of larval development and some even to adulthood. We uncover the origin of al…
Electron microscopic localization of nitric oxide I synthase in the organ of Corti of the guinea pig
1997
Nitric oxide synthase (NOS) activity has been detected previously in the mammalian cochlea at a light microscopic level. Here we present results of electron microscopic analysis for post-embedding immunoreactivity of neural-type NOS I in the cochlea of the guinea pig. Strong enzyme immunoreactivity was identified in the cytoplasm of inner and outer hair cells. Gold-labeled NOS I antibodies were mainly located in electron-dense areas of the cytoplasm, whereas electron-lucent regions of the receptor cells were nearly free from any immunoreactivity. In both types of hair cells anti-NOS I antibodies were also visible in the cuticular plates, hair bundles and nuclei. Further ultrastructural anal…
Storage Diseases: Diagnostic Position
2013
Storage diseases are metabolic multiorgan conditions, which may be divided into lysosomal and nonlysosomal diseases. Disorders of the lysosomal type require electron microscopy for morphological diagnosis. It is the metabolic substrate that determines involvement of the cell type or organ in the individual storage disease, allowing extracerebral biopsies, for instance, in the neuronal ceroid-lipofuscinoses (NCL). A hierarchy of tissues biopsied for diagnosis can be based on easy accessibility: blood lymphocytes, skin, conjunctiva, rectum, skeletal muscle. Lysosomal diseases are divided into vacuolar and nonvacuolar ones. NCL display variegated ultrastructural patterns. Drugs may induce lyso…
Primary Neural Precursors and Intermitotic Nuclear Migration in the Ventricular Zone of Adult Canaries
1998
New neurons continue to be born in the ventricular zone (VZ) of the lateral ventricles in the brain of adult birds. On the basis of serial section reconstruction and electron microscopy, we determined that the VZ of the adult canary brain is composed of three main cell types (A, B, and E). Type A cells were never found in contact with the ventricle and had microtubule-rich processes typical of young migrating neurons. Type B cells were organized as a pseudostratified epithelium, all contacted the ventricle, and most had a characteristic single cilium. Type E cells, also in contact with ventricle, were ultrastructurally similar to the mammalian multiciliated ependymal cells. After six inject…