Search results for "Calcium"

Ultrastructural localization of Ca2(+)-binding sites in the middle ear mucosa of the rat.

1990

Cations were precipitated with potassium-pyroantimonate in the middle ear mucosa of the rat and the distribution of the formed precipitates was studied by electron microscopy. The precipitate density in various cells of the different epithelia of the middle ear mucosa was determined on electron micrographs by counting the number of precipitates per unit area. Electron spectroscopic imaging was also performed to obtain information about the spatial distribution of the precipitates and their elemental composition.

Morphologic Damage and Changes of Intracellular Calcium-Binding Sites after Acute Noise Trauma in the Organ of Corti of the Guinea Pig

1993

In guinea pigs, an acute acoustic trauma was created by 6 consecutive gunshots. The sound pressure at the ear drum was 156 +/- 4 dB, the frequency maximum was between 4 and 6 kHz. Sixty hours after the noise trauma, the animals were decapitated, and the cochleae were prepared for microscopic analysis of the resulting trauma to the organ of Corti. During the process of fixation, the potassium-pyroantimonate precipitation reaction was performed to localize calcium-binding sites. The pattern of cell morphology and the distribution of calcium-binding sites was compared to that of normal control animals. Morphologic changes of the cells in the organ of Corti correlated with changes of the cellul…

Neuroprotective effect of flupirtine in prion disease

2003

Apoptotic neuronal cell death is a hallmark of prion diseases. The apoptotic process in neuronal cells is thought to be caused by the scrapie prion protein, PrPSc, and can be experimentally induced by its peptide fragment, PrP106-126. This process is a target for potential drugs to combat prion disease or to ameliorate its symptoms. Flupirtine (Katadolon), a pyridine derivative that is in clinical use as a nonopioid analgesic, has a potent cytoprotective effect, at concentrations above 1 microg/mL, on neuronal cells treated with PrP(Sc) or PrP106-126. This drug acts as an N-methyl-D-aspartate (NMDA) antagonist, but does not bind to NMDA receptors. Flupirtine normalizes the level of intracel…

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…

A suspicious calcium spike.

2015

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…

Effects of polyphenols and lipids from Pennisetum glaucum grains on T-cell activation: modulation of Ca2+ and ERK1/ERK2 signaling

2015

International audience; BACKGROUND: Pearl millet (PM), i.e., Pennisetum glaucum, is widely grown in Africa and known for its anti-oxidant and anti-hyperlipidemic properties.METHODS: The P. glaucum grains were obtained from the region of Ouled Aïssa (South of Algeria). We assessed the effects of phenolic compounds and lipids, extracted from seeds of P. glaucum, on rat lymphocyte proliferation, activated by phorbol 12-myristate 13-acetate and ionomycin. In order to explore signaling pathway, triggered by these compounds, we assessed interleukin-2 (IL-2) mRNA expression and extracellular signal-regulated kinase-1/2 (ERK1/ERK2) phosphorylation. Finally, we determined increases in free intracell…

Pentachlorophenol accumulation in the freshwater mussels Anodonta anatina and Pseudanodonta complanata, and some physiological consequences of labora…

1995

Freshwater mussels Anodanta anatina and Pseudanodonta complanata were exposed to (14C)-pentachlorophenol. The wet weight based bioconcentration factor (BCF = activity in animal per activity in water) at steady state varied from 80 to 120 for A. anatina and from 61 to 85 for P. complanata. The species did not differ significantly in their wet weight or lipid based BCFs but dry weight based values were significantly higher (40-50%) for A. anatina. The soft tissue dry weight and dry weight based condition index of A. anatina (Cl4 = soft tissue dry weight per shell length) differed significantly between natural mussel populations. In animals kept from 4 to 8 months in laboratory conditions, the…

Acid stress in respect to calcium and magnesium concentrations in the plasma of perch during maturation and spawning

1988

Plasma calcium and magnesium concentrations in perch,Perca fluviatilis, were monitored in an acid lake, Lake Iso Tenhetty (pH ∼5, Al concentrations 0.3–0.5 mg l-1) compared with a nearby reference lake, Lake Paijanne, in Southern Finland. The effect of acid stress could be noticed as 1/3 lower fecundity of perch in the acid lake. Plasma Ca concentrations were temporarily lower in the middle of the winter in the fish of the acid lake, and in April–May samples the situation was opposite. Plasma Mg concentration was also lower in the perch from the acid lake in midwinter months, when compared with the double as high values (∼3 mmol l-1) from the reference lake. Elevated level of plasma Mg have…

Corrigendum to “Polyvascular subclinical atherosclerosis in familial hypercholesterolemia: The role of cholesterol burden and gender” [Nutr Metab Car…

2019

International audience; Background and aim: Heterozygous familial hypercholesterolemia (HeFH) is a genetic disease characterized by a heterogeneous phenotype. The assessment of cardiovascular (CV) risk is challenging for HeFH. Cholesterol burden (CB) allows to estimate the lifelong exposure to high levels of cholesterol. The aim of this study was to analyze the distribution of subclinical athero-sclerosis and the relationship between atherosclerosis and the CB in a sample of HeFH patients, focusing on sex-related differences. Methods and Results: 154 asymptomatic HeFH subjects underwent coronary-artery-calcium score (CACs) and Doppler ultrasound of carotid and femoral arteries. Yearly lipid…