Search results for "RATS"
showing 10 items of 3537 documents
Differential staining of mucin granules from epoxy resin sections by a phosphotungstic acid-methyl green procedure.
1991
After treatment of epoxy resin semithin sections from glutaraldehyde fixed rat large intestine with 5% aqueous phosphotungstic acid (PTA), staining with unpurified 0.2% solutions of methyl green at 60 C for 5 min produces a color differentiation between mucin granules of goblet cells. Some mucin granules and the glycocalyx appear deep green while the remaining granules, luminal mucin and collagen fibers are pink. The known contamination of unpurified methyl green with crystal violet seems to be responsible for the pink staining reaction of the latter structures, which also present an orange-red fluorescence under green exciting light. Electron microscopic observations show selective contras…
Isoproterenol inhibits fluid-phase endocytosis from early to late endosomes
1999
We have shown recently that isoproterenol affects both the cellular location and the morphology of late endosomes in a pH-dependent manner [Marjomäki et al., Eur. J. Cell Biol. 65, 1-13 (1994)]. In this study, using fluorescence and quantitative electron microscopy, we wanted to examine further what is the fate of internalized markers during their translocation from early to late endosomes under isoproterenol treatment. Fluorescein dextran internalized for 30 min (10-min pulse followed by a 20-min chase) showed accumulation in the cellular periphery during isoproterenol treatment in contrast to the control cells, which accumulated dextran in the perinuclear region. Quantitative electron mic…
At reduced temperature, endocytic membrane traffic is blocked in multivesicular carrier endosomes in rat cardiac myocytes.
1998
Temperatures around 20 degrees C are known to block degradation of endocytosed material by preventing its transport to lysosomes, accordingly reduced temperature has been widely used to define endosomes. Newer studies have revealed that the low temperature block is proximal to perinuclear late endosomes, but it is not clear whether the block is already in early endosomes, or whether the traffic proceeds to multivesicular carrier endosomes which mediate transport from early to late compartments. We have now focused on this problem using rat cardiac myocytes. First, cell fractionation on Percoll gradients showed that at reduced temperatures (22 degrees C and 26 degrees C), with prolonged chas…
Alkaline hydrolysis/methylation-acetylation: a new technique for ultrastructural DNA cytochemistry.
1991
SUMMARY A new technique for the visualization of DNA-containing structures in electron microscopy is described. Samples of glutaraldehyde-fixed bone marrow from rats were subjected to alkaline hydrolysis to remove RNA and the phosphate of phospho-proteins, followed by a combined blockage of protein carboxyl and amino groups through methylation-acetylation. After uranyl acetate staining of epoxy-embedded ultrathin sections, chromatin from all cell types showed a highly selective and intense electron opacity. Staining methods for DNA were also positive in semithin sections. This simple procedure could be very useful in ultrastructural cytochemistry of DNA and chromatin.
Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium.
1999
To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium [Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-alpha-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mG…
La tapicería de la expulsión de los moriscos : un proyecto frustrado de Rodrigo Calderón
2018
espanolEl articulo pone en relacion la serie ya conocida de pinturas titulada «La expulsion de los moriscos del Reino de Valencia» con una documentacion inedita de un encargo realizado por Rodrigo Calderon al virrey de Valencia, marques de Caracena, que incluia, ademas de la narracion de la expulsion, una vista de la ciudad de Valencia y retratos de los protagonistas, y que debia convertirse en una coleccion de tapices nunca realizada. EnglishThis paper deals with an already known series of paintings titled The Expulsion of the Moriscos from the Kingdom of Valencia and provides unpublished documentation of a commission made by Rodrigo Calderon to the viceroy of Valencia, Marquis of Caracena…
Lucrècia Borja. L'alteració d’una identitat i l’errònia atribució de la pintura de Flora de Bartolomeo Veneto
2017
Resum: Aquest treball preten emfatitzar l’erronia identitat que ha arribat fins als nostres dies de Lucrecia Borja i l’equivocada atribucio que se n’ha fet d’alguns retrats. Com ara, la pintura de Flora (c.1520), pintada per Bartolomeo Veneto, que ha passat a la historia com una indissoluble identificacio de Lucrecia. Els estudis actuals han demostrat que representa un model ideal influit pel context literari probablement relacionat amb Pietro Bembo. Durant el Renaixement, els retrats representen molt mes que una identitat concreta i mimetica. Son suports de prestigi i transmissio ideologica, de virtuts morals, memoria, etc. En l’ambit artistic venecia de principis del segle XVI sorgeixen m…
Algunas consideraciones sobre el urbanismo público en Valencia durante la primera mitad del siglo XV = Some thoughts on public urbanism in Valencia d…
2015
El urbanismo público bajomedieval en la ciudad de Valencia se rigió principalmente en base a la actuación de los jurats, el poder ejecutivo de ésta, y la Junta de Murs i Valls, una institución creada el 1358 para gestionar las obras de muros, valladares o caminos de la urbe y su término, entre otras competencias. El devenir de este urbanismo, que cabe separar pero no individualizar del mercado inmobiliario privado, se debe entender, como se pretende enfocar en este artículo, a partir de interpretaciones económicas y sociales y que van más allá de las estrictamente estéticas o artísticas. A través de las fuentes administrativas (Manuals de Consells) se puede analizar la participación activa …
Effects of Anandamide and Noxious Heat on Intracellular Calcium Concentration in Nociceptive DRG Neurons of Rats
2007
As an endogenous agonist at the cannabinoid receptor CB1 and the capsaicin-receptor TRPV1, anandamide may exert both anti- and pronociceptive actions. Therefore we studied the effects of anandamide and other activators of both receptors on changes in free cytosolic calcium ([Ca2+]i) in acutely dissociated small dorsal root ganglion neurons (diameter: ≤30 μm). Anandamide (10 μM) increased [Ca2+]iin 76% of the neurons. The EC50was 7.41 μM, the Hill slope was 2.15 ± 0.43 (mean ± SE). This increase was blocked by the competitive TRPV1-antagonist capsazepine (10 μM) and in Ca2+-free extracellular solution. Neither exclusion of voltage-gated sodium channels nor additional blockade of voltage-gate…
Coexpression of heat-evoked and capsaicin-evoked inward currents in acutely dissociated rat dorsal root ganglion neurons.
1997
Noxious heat is able to activate heat-sensitive nociceptors in the skin very rapidly, but little is known about the mechanisms by which heat is transduced. We used the whole-cell patch-clamp technique to study the effects of noxious heat and capsaicin on freshly dissociated rat dorsal root ganglion neurons in vitro. Using temperatures between 41 degrees C and 53 degrees C, 8 of 19 small neurons (phior = 30 microm) exhibited a heat-evoked inward current. All heat-sensitive neurons tested were also capsaicin-sensitive. Moreover, the heat response tended to be enhanced after capsaicin (360 +/- 150 pA versus 125 +/- 45 pA, P0.1, n = 7). Two of five heat-insensitive neurons were excited by capsa…