Search results for " calcium."
showing 10 items of 341 documents
An increase of hippocampal calretinin-immunoreactive neurons correlates with early febrile seizures in temporal lobe epilepsy
1999
Numerous studies indicate that initial precipi- tating injuries (IPI) such as febrile seizures during early childhood may play a pivotal role in the pathogenesis of temporal lobe epilepsy (TLE) and Ammon's horn sclero- sis (AHS). Previous data demonstrate an increase of hori- zontally oriented neurons in molecular layers of hip- pocampal subfields, which are immunoreactive for calre- tinin (CR-ir) and resemble Cajal-Retzius-like cells. Cajal- Retzius cells are transiently expressed in the murine de- veloping hippocampus and are critically involved in neu- ronal pattern formation. Here we investigated a potential relationship between the distribution of horizontally ori- ented calretinin-imm…
Mixed methods analysis of Health-Related Quality of Life in ambulant individuals affected with RYR1-related myopathies pre-post-N-acetylcysteine ther…
2020
Purpose: To characterize Health-Related Quality of Life (HRQoL) in ambulant individuals with RYR1-RM and to determine if a qualitative PRO tool (subjective self-assessment) complements PROMIS and Neuro-QoL scales to detect changes in HRQoL in ambulant individuals with RYR1-RM post N-acetylcysteine (NAC) treatment. Methods: The study used a mixed methods research (MMR) design applying methodological triangulation. Qualitative data were collected via semi-structured interviews using open-ended questions. Quantitative data were gathered through PROMIS and Neuro-QoL instruments. Additionally, qualitative data were transformed into quantitative data for subjective self-assessment and frequency a…
A53T-Alpha-Synuclein Overexpression Impairs Dopamine Signaling and Striatal Synaptic Plasticity in Old Mice
2010
BACKGROUND: Parkinson's disease (PD), the second most frequent neurodegenerative disorder at old age, can be caused by elevated expression or the A53T missense mutation of the presynaptic protein alpha-synuclein (SNCA). PD is characterized pathologically by the preferential vulnerability of the dopaminergic nigrostriatal projection neurons. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used two mouse lines overexpressing human A53T-SNCA and studied striatal dysfunction in the absence of neurodegeneration to understand early disease mechanisms. To characterize the progression, we employed young adult as well as old mice. Analysis of striatal neurotransmitter content demonstrated that dopamine (DA…
Amorphous, nanocrystalline and crystalline calcium carbonates in biological materials
2010
Raman spectroscopy is a powerful tool in identifying different calcium carbonate polymorphs. Here, the method is applied to cultured pearls from freshwater (genus Hyriopsis) and marine bivalve species (Pinctada maxima) as well as to shells of Diplodon chilensis patagonicus bivalves. Raman spectra for vaterite, detected for the first time in an adult shell, and amorphous calcium carbonate (ACC) are discussed. Results for ACC are compared with those of synthetically produced ACC and with the Raman spectroscopic features of stable biogenic ACC from the crustacean Porcellio scaber. Decomposition of the most intense signal of all calcium carbonate polymorphs—the ν1 symmetric stretching mode of t…
Common genetic denominators for Ca++-based skeleton in Metazoa: role of osteoclast-stimulating factor and of carbonic anhydrase in a calcareous spong…
2012
Calcium-based matrices serve predominantly as inorganic, hard skeletal systems in Metazoa from calcareous sponges [phylum Porifera; class Calcarea] to proto- and deuterostomian multicellular animals. The calcareous sponges form their skeletal elements, the spicules, from amorphous calcium carbonate (ACC). Treatment of spicules from Sycon raphanus with sodium hypochlorite (NaOCl) results in the disintegration of the ACC in those skeletal elements. Until now a distinct protein/enzyme involved in ACC metabolism could not been identified in those animals. We applied the technique of phage display combinatorial libraries to identify oligopeptides that bind to NaOCl-treated spicules: those oligop…
Synthesis and studies of calcium channel blocking and antioxidant activities of novel 4-pyridinium and/or N-propargyl substituted 1,4-dihydropyridine…
2014
The novel 1,4-dihydropyridine derivatives containing the cationic pyridine moiety at the position 4, and the N-propargyl group as a substituent at position 1 of the 1,4-DHP cycle were designed, synthesised, and assessed in biological tests. Among all the novel compounds, the 4-(N-dodecyl) pyridinium group-containing compounds 11 (without the N-propargyl group) and 12 (with the N-propargyl group) demonstrated the highest calcium antagonistic properties against neuroblastoma SH-SY5Y (IC50 about 5–14 mM) and the vascular smooth muscle A7r5 cell (IC50 – 0.6–0.7 mM) lines, indicating that they predominantly target the L-type calcium channels. These compounds showed a slight total antioxidant act…
Vascular Activity of (-)-Anonaine, (-)-Roemerine and (-)-Pukateine, Three Natural 6a(R)-1,2-Methylenedioxyaporphines with Different Affinities for α1…
2004
We have studied the mechanism of action of three 6a( R)-1,2-methylenedioxyaporphines as vasorelaxant compounds. The alkaloids assayed showed different affinities for the three human cloned alpha (1)-adrenoceptor (AR) subtypes stably expressed in rat-1 fibroblasts, showing lower affinity for alpha(1B)-AR with regard to the alpha(1A)- or alpha(1D)-subtypes. These three natural compounds are more potent inhibitors of [ (3)H]-prazosin binding than of [ (3)H]-diltiazem binding to rat cerebral cortical membranes. As all these alkaloids inhibited noradrenaline (NA)-induced [ (3)H]-inositol phosphate formation in cerebral cortex and rat tail artery, they may be safely viewed as alpha (1)-AR antagon…
Toxicological Impact of Rare Earth Elements (REEs) on the Reproduction and Development of Aquatic Organisms Using Sea Urchins as Biological Models
2022
The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, includi…
Primary Cell Culture of Fresh Water Hyriopsis cumingii Mantle/Pearl Sac Tissues and Its Effect on Calcium Carbonate Mineralization
2014
Primary cell cultures of the fresh water Hyriopsis cumingii mantle and pearl sac tissues were produced in this study, and the influence of the tissue, cells, and secreted protein on calcium carbonate crystal nucleation and growth was studied. The study contributes to a further understanding of the influence of organic matrices on CaCO3 crystal formation. This research started from the protein level to the tissue/cell level, which is crucial for understanding the inorganic deposition process. The new data also add relevant theoretical approaches to an overall understanding of biomineralization processes. In the experimental groups with mantle or pearl sac tissue, the growth patterns of arago…
11,12-EET Stimulates the Association of BK Channel α and β1 Subunits in Mitochondria to Induce Pulmonary Vasoconstriction
2012
In the systemic circulation, 11,12-epoxyeicosatrienoic acid (11,12-EET) elicits nitric oxide (NO)- and prostacyclin-independent vascular relaxation, partially through the activation of large conductance Ca(2+)-activated potassium (BK) channels. However, in the lung 11,12-EET contributes to hypoxia-induced pulmonary vasoconstriction. Since pulmonary artery smooth muscle cells also express BK channels, we assessed the consequences of BKβ(1) subunit deletion on pulmonary responsiveness to 11,12-EET as well as to acute hypoxia. In buffer-perfused mouse lungs, hypoxia increased pulmonary artery pressure and this was significantly enhanced in the presence of NO synthase (NOS) and cyclooxygenase (…