Search results for "Dogs"
showing 10 items of 249 documents
Use of flow cytometry and confocal microscopy techniques to investigate early CdCl(2)-induced nephrotoxicity in vitro.
2001
CdCl(2) is a well-known toxic compound for the kidney in vivo and in vitro. We report here part of the results of an ECVAM (European Centre for the Validation of Alternative Methods) contract study, aimed at establishing and assessing several flow cytometric and confocal microscopic endpoints for use in an in vitro nephrotoxicity model. Three renal tubule cell lines, OK (opossum, proximal tubule origin), LLC-PK1 (pig, proximal tubule origin) and MDCK (dog, distal tubule origin) were exposed for 1, 5 and 24 h to 25 microM and 100 microM CdCl(2). The results obtained for mitochondrial membrane potential showed a decrease in all the cell lines after 5 h of treatment with both CdCl(2) concentra…
Ultrastructural study of primary canine and human pigmentary retinopathy
1985
An electron microscopic study was performed on eyes of Labrador dogs afflicted with progressive retinal atrophy (PRA). There was complete loss of photoreceptors, atrophy of the remaining retina and gliosis in the peripheral part while the central retina showed incomplete loss of photoreceptors and an almost total disappearance of photoreceptor outer segments. Melanin-bearing cells, largely containing melanolysosomes, were found deep inside the retina. This electron microscopic study also incorporated the retina of a middle-aged woman affected by retinopathia pigmentosa (RP). The fine structure of the diseased retina showed a similar pattern of lesions, more pronounced in the periphery of th…
Role of mitochondria in parvovirus pathology.
2014
Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV) associated with the mitochondrial outer membrane from the onset of infection. During viral entry a transient depolarization of the mitochondrial transmembrane potential and increase in ROS level was detected. Subsequently, mitochondrial homeostasis was normalized shortly, as detected by rep…
Small bowel motility: relationship between smooth muscle contraction and electroenterogram signal.
2000
A study is made to correlate the electrical and mechanical activity of the smooth muscle of the small bowel. Bioelectrical signal recording from the intestinal serosa (electroenterogram) comprises a slow wave (SW) and spike burst (SB), though only the latter reflects intestinal pressure. The electroenterogram and smooth muscle pressure are simultaneously recorded in the canine small bowel. Spectral and time series analysis of the electroenterogram are performed to establish those electrical parameters that best reflect intestinal pressure. The results reveal an underlying correlation between the estimated parameters of electrical activity and smooth muscle pressure. In addition, parameters …
Variability of permeability estimation from different protocols of subculture and transport experiments in cell monolayers.
2014
Abstract Introduction In vitro models with high predictive ability have been revealed as strong tools for pharmaceutical industry. However, the variability in permeability estimations complicates the comparison and combination of data from different laboratories and it makes necessary the careful validation of the model and the continuous suitability demonstration. The adequate standardization of pre-experimental, experimental and post-experimental factors might help to reduce the inter- and intra-laboratory variability in permeability values. Methods The objective of this paper is the evaluation of the effect of passage number, experimental protocol, time after seeding and calculation meth…
Regional distribution of blood flow in the renal cortex
1969
Es wird ein autoradiographisches Verfahren zur Bestimmung der regionalen Durchblutungsverteilung in differenziert strukturierten Organen beschrieben. Mit dieser neuen Methode wird die Durchblutung der Nierenrinde untersucht. Es wird nachgewiesen, dass die Durchblutungs- bzw. Widerstandsverteilung innerhalb der Rinde nicht einheitlich ist, sondern dass sich drei verschieden durchblutete, anatomisch voneinander abgrenzbare Teile unterscheiden lassen.
Muscarinic acetylcholine receptor trafficking in streptolysin O-permeabilized MDCK cells.
1996
We investigated the validity of streptolysin O (SLO)-permeabilized Madin-Darbin canine kidney (MDCK) cells which express muscarinic acetylcholine receptors (mAChRs) coupled to pertussis toxin-sensitive guanine nucleotide-binding proteins (G proteins) for the study of the molecular machinery that regulated mAChR internalization and recycling. Exposure of SLO-permeabilized cells to carbachol-reduced cell surface receptor number by up to 40% without changing total receptor number. The kinetics and maximal extent of receptor internalization as well as the potency of carbachol to induce receptor internalization were almost identical in SLO-permeabilized and non-permeabilized cells. Using this se…
Photoplethysmography in dogs and cats: a selection of alternative measurement sites for a pet monitor.
2018
Objective Photoplethysmography (PPG) is an increasingly popular health and well-being tool for monitoring heart rate and oxygen saturation. Due to the pigmentation and hairiness of dogs and cats, a pulse oximeter is routinely placed solely on the tongue. As this approach is feasible only for pet monitor use during surgical procedures, we investigate PPG signal quality on several other measurement sites that would be better tolerated by conscious animals. Approach Acquired PPG signals are analyzed by four signal quality indices: mean baseline, signal power, kurtosis, and tolerance score. Main results In dogs, the metacarpus and tail can be substituted for oral pulse oximeter placement since …
Autoradiographic technique to assess distribution of blood flow within organs
1969
A method is described for assessing the distribution of blood flow within organs. Microspheres, 5–50 μ in diameter, labelled with a beta-emitting isotope were injected into the left ventricle of experimental animals. The distribution of the indicator within the tissues, which is assumed to represent the regional distribution of flow, was visualized and measured quantitatively by autoradiography. Local flow rates in areas of about 1,2 mm in diameter could be determined. Application of the technique for the study of regional myocardial and renal circulation is demonstrated.
Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papill…
2014
Antiviral activity has been demonstrated for different tannin-rich plant extracts. Since tannins of different classes and molecular weights are often found together in plant extracts and may differ in their antiviral activity, we have compared the effect against influenza A virus (IAV) of Hamamelis virginiana L. bark extract, fractions enriched in tannins of different molecular weights and individual tannins of defined structures, including pseudotannins. We demonstrate antiviral activity of the bark extract against different IAV strains, including the recently emerged H7N9, and show for the first time that a tannin-rich extract inhibits human papillomavirus (HPV) type 16 infection. As the …