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Results for “Fluorescence Microscopy”

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At least 1,459 records · Page 81Linked to original sources
PubMed1984

Comparison of a commercial enzyme-linked immunosorbent assay with electron microscopy, fluorescent antibody, and virus isolation for the detection of bovine and porcine rotavirus.

The purpose in this study was to compare the sensitivity of a commercial enzyme-linked immunosorbent assay (ELISA) with electron microscopy (EM), fluorescent antibody (FA), and virus isolation (VI) for the detection of bovine and porcine rotavirus (RV). Seventy-three bovine and 116 porcine accessions were evaluated by 1 or all 4 diagnostic tests, where suitable specimens were available. For the bovine samples, agreement was 33% between FA and EM, 33% between FA and ELISA, and 92% between EM and ELISA. For the porcine samples, agreement was 79% between EM and FA, 72% between EM and ELISA, and 82% between ELISA and FA. Virus was isolated from 68% and 41% of the bovine and porcine fecal samples, respectively. Commercial ELISA was as sensitive as EM, but was more sensitive than FA or VI for the detection of RV in bovine feces. Electron microscopy was more sensitive than FA, ELISA, or VI for detection of RV in porcine feces. The ELISA was an advantageous alternative to the conventional methods of EM, FA, and VI for the diagnosis of RV in calf feces, but not for porcine feces.

Animals↗
PubMed1992

Observation of the blood-brain barrier function and vasomotor response in rat microcirculation using intravital fluorescence microscopy.

The blood-brain barrier function and the vasomotor response in rat microcirculation was studied using a closed cranial window technique and an intravital fluorescence microscope with an attempt to reduce both the light intensity and the amount of 2% Na(+)-fluorescein to as little as possible. The light intensities in the focus were less than or equal to 2.5 mW/cm2, and with the low-light TV camera we were able to reduce the total amount of the dye to less than or equal to 0.7 ml during 6-h experiments. Observing the brain surface every 30 min showed that the barrier function remained intact for up to 6.0 h following the first iv administration of the dye. This study has reconfirmed that the pial vessels have physiological vasomotor responses (e.g., CO2 reactivity). The osmotic barrier disruption started at a small venule 10 min after the start of superfusion with mannitol (1000 mOsm/liter). In conclusion, the microscope system and the small animal model used in this study were useful in studying the blood-brain barrier function and the vasomotor response simultaneously under various experimental conditions.

Animals↗
PubMed2006

Spatially and temporally synchronized atomic force and total internal reflection fluorescence microscopy for imaging and manipulating cells and biomolecules.

The atomic force microscope is a high-resolution scanning-probe instrument which has become an important tool for cellular and molecular biophysics in recent years but lacks the time resolution and functional specificities offered by fluorescence microscopic techniques. To exploit the advantages of both methods, here we developed a spatially and temporally synchronized total internal reflection fluorescence and atomic force microscope system. The instrument, which we hereby call STIRF-AFM, is a stage-scanning device in which the mechanical and optical axes are coaligned to achieve spatial synchrony. At each point of the scan the sample topography (atomic force microscope) and fluorescence (photon count or intensity) information are simultaneously recorded. The tool was tested and validated on various cellular (monolayer cells in which actin filaments and intermediate filaments were fluorescently labeled) and biomolecular (actin filaments and titin molecules) systems. We demonstrate that with the technique, correlated sample topography and fluorescence images can be recorded, soft biomolecular systems can be mechanically manipulated in a targeted fashion, and the fluorescence of mechanically stretched titin can be followed with high temporal resolution.

Actin Cytoskeleton↗
PubMed1993

Clinical results after doxorubicin extravasation treated with excision guided by fluorescence microscopy.

Doxorubicin (DR) and epirubicin (ER) produce progressive tissue necrosis when extravasation occurs. Early detection and excision of all affected tissue is important. The clinical experience with fluorescence microscopic guided detection and excision in 24 patients is evaluated. 9 patients with fluorescence negative specimens were kept under observation without excision. None developed necrosis. Wide excision was performed on 15 patients with fluorescence positive specimens. Sequelae, defined as impaired function of the affected limb at the last control examination in the out-patient clinic, were observed in 8 patients. 4 of 5 patients with extravasation in the hand and 2 of 3 with extravasation in the cubital fossa were among these. Delay, defined as time from injury to surgery, was a median of 7 h, range from 3 h to 69 days. Patients developing sequelae had a median delay of roughly 4-fold that of patients without these complications. Patients with extravasation in the cubital fossa were hospitalised for the longest period: 30 days, range 24-45 days, vs. 12 days, range 7-80 days, for those with extravasation at other sites (P < 0.03). Our conclusions are: (1) fluorescence microscopic analysis is a reliable method for the detection and delineation of extravasation of DR or ER. (2) Do not use the cubital fossa or hand for the infusion of these cytostatics. (3) Act promptly if extravasation is suspected--delay leads to sequelae.

Adolescent↗
PubMedDate not supplied

Conventional and confocal epi-reflection and fluorescence microscopy of the rat kidney in vivo.

To visualize superficial and accessible renal tubule cells functioning in situ and to relate what we can 'see' to what we know of their function from more invasive in vivo or less direct in vitro studies means applying and adapting recent advances in epifluorescence and confocal microscopy to improve image resolution and to combine this with the use of fluorescent labels to monitor the handling of specific molecules by the proximal and distal renal tubule cells in vivo. Doing this in living tissue is novel, especially in the kidney. Application of confocal microscopy to the imaging of living tissue, as opposed to isolated cells, has not been widely reported. The kidney surface has been imaged before using the confocal microscope and in preliminary studies we have extended this by using a different confocal system with and without fluorescence. While the studies published up to now have been morphological, comparing standard renal (structural) histology of surface glomeruli and renal tubules with the corresponding in vivo confocal images, more dynamic, real-time studies have been limited. Individual red blood cells can be seen flowing around the peritubule capillary network and nucleated white blood cells can also be distinguished. Tubule cells, endothelial cells, the proximal tubule cell brush border and cell mitochondria can be visualized. Filtration and secretion can be observed, and the early and late parts of the proximal tubule distinguished, and the distal tubule recognized. Localization of fluorescently labeled insulin to the luminal brush border and progressive uptake of label and distribution within proximal tubule cells toward the basolateral (blood side) membrane can be demonstrated. The possibility of monitoring hemodynamic changes and tracking the filtration, uptake, secretion and absorption of fluorescently tagged molecules, as well as intracellular fluorescence, e.g. calcium or pH, is an exciting prospect and is ripe for detailed exploration.

Animals↗
PubMed1986

Localization of an aminoglycoside (streptomycin) in the inner ear after its systemic administration. A histochemical study using fluorescence microscopy.

We used the simple method of direct cytofluorescence to detect the presence of the aminoglycoside, streptomycin, in the inner ear after its systemic administration. In the cochlea, fluorescence was observed in the organ of Corti, the spiral ganglion, the nerve fibres, the vascular stria and Reissner's membrane; in the vestibulum, fluorescence was seen in the crista ampullaris and the planum semilunatum. The localization of the drug was related to the distribution of its specific receptor, triphosphoinositide (TPI); therefore, it is reasonable to assume that aminoglycosides exert their toxic effects by binding to TPI.

Animals↗
PubMedDate not supplied

'In situ' high pressure confocal Ca(2+)-fluorescence microscopy in skeletal muscle: a new method to study pressure limits in mammalian cells.

We combined 'in situ' high pressure microscopy with confocal laser scanning microscopy to directly study Ca2+ homeostasis in intact mammalian (murine) skeletal muscle fibres during high pressure exposure up to 35 MPa. Cytosolic Fluo-4 and mitochondrial Rhod-2 Ca2+ fluorescence were simultaneously monitored. To separate changes in Ca2+ and direct/indirect effects of pressure on the dye, experiments in permeabilized ('skinned') muscle fibres were performed at a fixed Ca2+ concentration. Normalized Fluo-4 fluorescence sharply declined up to 10 MPa but showed a plateau between 10 MPa and -35 MPa. In the intact fibre, Fluo-4 fluorescence exponentially decreased during pressurization to 35 MPa with a pressure constant of pi-5 MPa whereas mitochondrial Rhod-2 fluorescence exponentially increased with a four-fold larger pi. Holding the pressure at 35 MPa almost did not change Fluo-4 fluorescence. However, Rhod-2 fluorescence started to decrease after -40 min. Upon decompression, Rhod-2 and Fluo-4 fluorescence increased exponentially with similar pi. However, initial Fluo-4 fluorescence values were not restored. Our results are in agreement with pressure induced Ca2+ leakage from the sarcoplasmic reticulum. Ca2+ might then be taken up in large amounts by mitochondria preventing cytosolic increase in Ca2+. Prolonged pressure applications (-40 min at 35 MPa) seem to destabilize mitochondrial function with release of Ca2+ from mitochondria back into the cytosol and eventually mechanical activation resulting in irreversible contractures. The pressure induced disturbance of Ca2+ homeostasis might have important implications for the pressure exposure limits and/or dive profiles of deep sea mammals.

Aniline Compounds↗
PubMed2006

Analyzing proteome topology and function by automated multidimensional fluorescence microscopy.

Temporal and spatial regulation of proteins contributes to function. We describe a multidimensional microscopic robot technology for high-throughput protein colocalization studies that runs cycles of fluorescence tagging, imaging and bleaching in situ. This technology combines three advances: a fluorescence technique capable of mapping hundreds of different proteins in one tissue section or cell sample; a method selecting the most prominent combinatorial molecular patterns by representing the data as binary vectors; and a system for imaging the distribution of these protein clusters in a so-called toponome map. By analyzing many cell and tissue types, we show that this approach reveals rules of hierarchical protein network organization, in which the frequency distribution of different protein clusters obeys Zipf's law, and state-specific lead proteins appear to control protein network topology and function. The technology may facilitate the development of diagnostics and targeted therapies.

Dermatitis, Atopic↗
PubMed1991

Detection of epidermal growth factor receptors and E-cadherins in the basolateral membrane of A431 cells by laser scanning fluorescence microscopy.

We have examined the localization of epidermal growth factor (EGF) receptors and E-cadherins in cultured A431 cells, an epidermoid carcinoma cell line, using a laser scanning fluorescence microscope. The fluorescence signals generated by monoclonal antibodies against EGF receptor and E-cadherin were localized mainly in the cell-cell contact sites, about 3 microns in width. When these areas for cell adhesion were scanned perpendicularly, fluorescence was detected from a point 4 microns from the cell base for a distance of 8 microns towards the cell surface (about 16 microns from the cell base). These data suggest the subcellular localization of EGF receptors and E-cadherins in the basolateral membrane of A431 cells.

Cadherins↗
PubMed1981

Localization of actin in the cortex of Paramecium tetraurelia cells by immuno- and affinity-fluorescence microscopy.

The cortex of the ciliate Paramecium tetraurelia has been examined both with whole cells and with isolated surface complexes (pellicles) for the presence and distribution of actin, using direct fluorescence labeling with antibodies monospecific for Paramecium actin, with DNase I or with heavy meromyosin, all tagged with FITC as a fluorochrome. The results obtained with the three different methods were similar. Actin is concentrated in the cilia and--clearly visible only after deciliation--in the basal bodies. The docking site of secretory vesicles (trichocysts) onto the cell membrane does not display any selective actin content. This does not preclude the interaction with actin at other sites of the trichocysts, since diffuse fluorescence labeling in deeper layers of the cell did not allow us yet to analyze the distribution of actin throughout the cell body. However, our data would preclude any direct involvement of actin at the site of exocytotic membrane fusion proper.

Actins↗