Search results for "CALCIUM"
showing 10 items of 1740 documents
Specific suppression of pentylenetetrazol-induced epileptiform discharges in CA3 neurons (hippocampal slice, guinea pig) by the organic calcium antag…
1989
Antiepileptic actions of the organic calcium antagonists flunarizine (cinnarizine derivate) and verapamil (papaverin derivat) on pentylenetetrazol-induced epileptic bioelectric activity were tested in CA3 neurones of hippocampal slices. In all experiments both calcium antagonists reduced the amplitudes and/or durations of paroxysmal depolarizations as well as their rate of occurrence, when the bath concentrations of flunarizine or verapamil exceeded 20 mumol/l. When they were added to the bath solution before pentylenetetrazol application, recordings of the resting membrane potential, of the membrane resistance, of action potentials and of spontaneous as well as of evoked excitatory and inh…
Identification of Morphological Biosignatures in Martian Analogue Field Specimens Using In Situ Planetary Instrumentation
2008
International audience; We have investigated how morphological biosignatures (i.e., features related to life) might be identified with an array of viable instruments within the framework of robotic planetary surface operations at Mars. This is the first time such an integrated lab-based study has been conducted that incorporates space-qualified instrumentation designed for combined in situ imaging, analysis, and geotechnics ( sampling). Specimens were selected on the basis of feature morphology, scale, and analogy to Mars rocks. Two types of morphological criteria were considered: potential signatures of extinct life ( fossilized microbial filaments) and of extant life (crypto-chasmoendolit…
Manganese interferes with calcium, perturbs ERK signaling, and produces embryos with no skeleton.
2011
Manganese (Mn) has been associated with embryo toxicity as it impairs differentiation of neural and skeletogenic cells in vertebrates. Nevertheless, information on the mechanisms operating at the cellular level remains scant. We took advantage of an amenable embryonic model to investigate the effects of Mn in biomineral formation. Sea urchin (Paracentrotus lividus) embryos were exposed to Mn from fertilization, harvested at different developmental stages, and analyzed for their content in calcium (Ca), expression of skeletogenic genes, localization of germ layer markers, and activation of the extracellular signal-regulated kinase (ERK). By optical and immunofluorescence microscopy, we found…
G protein-coupled odorant receptors underlie mechanosensitivity in mammalian olfactory sensory neurons
2014
Mechanosensitive cells are essential for organisms to sense the external and internal environments, and a variety of molecules have been implicated as mechanical sensors. Here we report that odorant receptors (ORs), a large family of G protein-coupled receptors, underlie the responses to both chemical and mechanical stimuli in mouse olfactory sensory neurons (OSNs). Genetic ablation of key signaling proteins in odor transduction or disruption of OR–G protein coupling eliminates mechanical responses. Curiously, OSNs expressing different OR types display significantly different responses to mechanical stimuli. Genetic swap of putatively mechanosensitive ORs abolishes or reduces mechanical res…
The Streptomyces coelicolor Small ORF trpM Stimulates Growth and Morphological Development and Exerts Opposite Effects on Actinorhodin and Calcium-De…
2020
In actinomycetes, antibiotic production is often associated with a morpho-physiological differentiation program that is regulated by complex molecular and metabolic networks. Many aspects of these regulatory circuits have been already elucidated and many others still deserve further investigations. In this regard, the possible role of many small open reading frames (smORFs) in actinomycete morpho-physiological differentiation is still elusive. In Streptomyces coelicolor, inactivation of the smORF trpM (SCO2038) – whose product modulates L-tryptophan biosynthesis – impairs production of antibiotics and morphological differentiation. Indeed, it was demonstrated that TrpM is able to interact w…
Mechanical and barrier properties of extruded film made from sodium and calcium caseinates
2014
Abstract Over the past few years, much interest has been placed into the investigation of increased barrier and mechanical properties of protein films via a multitude of approaches. Generally, these techniques involve modifications of interactions among protein molecules, such as ionic crosslinking using divalent ions. To evaluate the crosslinking effect of Ca 2+ cations, films were made from calcium caseinate (CaCAS) and/or sodium caseinate (NaCAS). The production of caseinate thin films was carried out in two steps: first thermoplastic pellets were made using a co-rotating twin-screw extruder, then they were transformed into thin films (60 μm) using a classical film blowing machine. Tensi…
Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials
2013
The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM).Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular pro…
Traditional endodontic surgery versus modern technique: a 5-year controlled clinical trial.
2014
In this study, we compared outcomes of traditional apicoectomy versus modern apicoectomy, by means of a controlled clinical trial with a 5-year follow-up. The study investigated 938 teeth in 843 patients. On the basis of the procedure performed, the teeth were grouped in 3 groups. Differences between the groups were the method of osteotomy (type of instruments used), type of preparation of retrograde cavity (different apicoectomy angles and instruments used for root-end preparation), and root-end filling material used (gray mineral trioxide aggregate or silver amalgam). Outcome (tooth healing) was estimated after 1 and 5 years, postoperatively. Clinical success rates after 1 year were 67% (…
Osseous reaction to implantation of two endodontic cements : mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)
2012
Aim: The aim of the present in vivo study was to determine bone tissue reaction to calcium enriched mixture (CEM) and mineral trioxide aggregate (MTA) using a rat femur model. Study Design: Sixty-three rats were selected and randomly divided into three groups of 21 each [experimental groups (n=15), control (n=6)]. Implantation cavities were prepared in each femoral bone and randomly filled with the biomaterials only in the experimental groups. The animals in three groups were sacrificed 1, 4, and 8 weeks postoperatively. Histologic evaluations comprising inflammation severity and new bone formation were blindly made on H&E-stained decalcified 6-µm sections. Results: At 1, 4, and 8 weeks aft…
Biocompatibility of three new calcium silicate-based endodontic sealers on human periodontal ligament stem cells.
2016
Aim To evaluate the biocompatibility of three calcium silicate-based endodontic sealers, Bioroot BC Sealer (Septodont, Saint-Maur-des-Fosses, France), Endoseal MTA (EndoSeal, Maruchi, Seoul, Korea) and Nano-ceramic Sealer (B&L Biotech, Fairfax, VA, USA) (NCS), on human periodontal ligament stem cells (hPDLSCs). Methodology Human periodontal ligament stem cells were cultured in the presence of various endodontic sealer eluates for 24 h. Cell viability was determined using the MTT assay. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. Also, an in vitro scratch wound-healing model was used to determine their effects in cel…