Critical transitions in pancreatic islets.

Calcium signals in pancreatic cells collectives show a sharp transition from uncorrelated to correlated state resembling a phase transition as the slowly increasing glucose concentration crosses the tipping point. However, the exact nature or the order of this phase transition is not well understood. Using confocal microscopy to record the collective calcium activation of cells in an intact islet under changing glucose concentration in increasing and then decreasing way, we first show that in addition to the sharp transition, the coordinated calcium response exhibits a hysteresis indicating a critical, first order transition.

Tracking Ca2+ Dynamics in NOD Mouse Islets During Spontaneous Diabetes Development.

Unlabelled: The mechanisms accounting for the functional changes of α- and β-cells over the course of type 1 diabetes (T1D) development are largely unknown. Permitted by our established technology of high spatiotemporal resolution imaging of cytosolic Ca2+ ([Ca2+]c) dynamics on fresh pancreas tissue slices, we tracked the [Ca2+]c dynamic changes, as the assessment of function, in islet α- and β-cells of female nonobese diabetic (NOD) mice during the development of spontaneous diabetes. We showed that, during the phases of islet inflammation, 8 mmol/L glucose-induced synchronized short [Ca2+]c events in β-cells were diminished, whereas long [Ca2+]c events were gradually more triggerable at substimulatory 4 and 6 mmol/L glucose.

Psychometric properties of ohip-edent b&h for conventional complete denture wearers.

This study assessed psychometric properties of the Bosnian language version the Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT), translated from the original English language version of and evaluated the Oral Health-related Quality of Life, in complete denture wearers before and after corrections of dentures. Specialist of dental prosthetic interviewed 117 edentulous patients before and after interventions. All patients had problems with their existing complete acrylic resin dentures.

High-resolution analysis of the cytosolic Ca events in β cell collectives in situ.

The release of peptide hormones is predominantly regulated by a transient increase in cytosolic Ca concentration ([Ca]). To trigger exocytosis, Ca ions enter the cytosol from intracellular Ca stores or from the extracellular space. The molecular events of late stages of exocytosis, and their dependence on [Ca], were extensively described in isolated single cells from various endocrine glands.

Physiological levels of adrenaline fail to stop pancreatic beta cell activity at unphysiologically high glucose levels.

Adrenaline inhibits insulin secretion from pancreatic beta cells to allow an organism to cover immediate energy needs by unlocking internal nutrient reserves. The stimulation of α2-adrenergic receptors on the plasma membrane of beta cells reduces their excitability and insulin secretion mostly through diminished cAMP production and downstream desensitization of late step(s) of exocytotic machinery to cytosolic Ca concentration ([Ca]). In most studies unphysiologically high adrenaline concentrations have been used to evaluate the role of adrenergic stimulation in pancreatic endocrine cells.

pH-Dependence of Glucose-Dependent Activity of Beta Cell Networks in Acute Mouse Pancreatic Tissue Slice.

Extracellular pH has the potential to affect various aspects of the pancreatic beta cell function. To explain this effect, a number of mechanisms was proposed involving both extracellular and intracellular targets and pathways. Here, we focus on reassessing the influence of extracellular pH on glucose-dependent beta cell activation and collective activity in physiological conditions.

Allosteric coupling between transmembrane segment 4 and the selectivity filter of TALK1 potassium channels regulates their gating by extracellular pH.

Opening of two-pore domain K channels (K2Ps) is regulated by various external cues, such as pH, membrane tension, or temperature, which allosterically modulate the selectivity filter (SF) gate. However, how these cues cause conformational changes in the SF of some K2P channels remains unclear. Herein, we investigate the mechanisms by which extracellular pH affects gating in an alkaline-activated K2P channel, TALK1, using electrophysiology and molecular dynamics (MD) simulations.

Dual Mode of Action of Acetylcholine on Cytosolic Calcium Oscillations in Pancreatic Beta and Acinar Cells In Situ.

Cholinergic innervation in the pancreas controls both the release of digestive enzymes to support the intestinal digestion and absorption, as well as insulin release to promote nutrient use in the cells of the body. The effects of muscarinic receptor stimulation are described in detail for endocrine beta cells and exocrine acinar cells separately. Here we describe morphological and functional criteria to separate these two cell types in situ in tissue slices and simultaneously measure their response to ACh stimulation on cytosolic Ca oscillations [Ca] in stimulatory glucose conditions.

Specific occlusal scheme for partially edentulous patients with TMD signs-preliminary report.

Background: The purpose of this study was to ascertain a specific occlusal scheme to reduce temporomandibular disorder signs and symptoms in the therapy of partially edentulous patients with removable partial acrylic dentures.

Methodology: Thirty-four partially edentulous patients who had unilateral free-end saddle in the mandible along with a history of TMD signs and symptoms were prosthodontically treated, fitting them with new removable acrylic partial dentures (NRAPD) for their lower jaws. The new and specific occlusal scheme was established with tendencies to restrict mandibular functional movements partly; this proved somewhat awkward, but had the benefit of allowing continued unrestricted occlusal contacts in grinding and functional movements.

Marginal Gaps between 2 Calcium Silicate and Glass Ionomer Cements and Apical Root Dentin.

Introduction: The outcome of periapical surgery has been directly improved with the introduction of novel material formulations. The aim of the study was to compare the retrograde obturation quality of the following materials: calcium silicate (Biodentine; Septodont, Saint-Maur-des-Fosses, France), mineral trioxide aggregate (MTA+; Cerkamed Company, Stalowa Wola, Poland), and glass ionomer cement (Fuji IX; GC Corporation, Tokyo, Japan).

Methods: Materials' wettability was calculated concerning the contact angles of the cements measured using a glycerol drop.

Clinical Characteristics of Abutment Teeth with Gingival Discoloration.

Purpose: The grey-bluish discoloration of gingiva (known as "amalgam tattoo") does not appear only in the presence of amalgam restorations. It may also be seen in cases of teeth restored with cast dowels and porcelain-fused-to-metal (PFM) restorations. The aim of this article was to determine the clinical characteristics of abutment teeth with gingival discoloration.

Influence of the magnetic field on microorganisms in the oral cavity.

Unlabelled: Since the beginning of their lives, all living organisms are exposed to the influence of geomagnetic fields.

Objectives: With respect to the positive effects that magnetic fields have on human tissues, especially the bactericidal effect, this investigation aimed to assess their influence on the reduction of oral microorganisms.

Material And Methods: In order to obtain adequate specimens of dental plaque deposit, microbes such as Streptococcus parasanguinis, Staphylococcus epidermidis, Rhodococcus equi and Candida albicans were isolated from the human mouth.

A preliminary study on local administration of dexamethasone after tooth extraction--Better preservation of residual alveolar ridge?

Background/aim: It is important that the height of the edentulous alveolar ridge after tooth extraction remains at a reasonable acceptable level for as long as possible. The aim of this study was to report preliminary results of the clinical effect of local oral submucous administration of dexamethasone after tooth extractions in order to prepare alveolar supporting tissues for acceptance of removable dentures.

Methods: In a total of 15 patients (11 partially and 4 completely edentulous) the quantity of 0.

Volumetric analysis of amygdala, hippocampus, and prefrontal cortex in therapy-naive PTSD participants.

Objective: In our study we have hypothesized that volume changes of amygdala, hippocampus, and prefrontal cortex are more pronounced in male posttraumatic stress disorder participants.

Material And Methods: We have conducted a study of 79 male participants who underwent MRI brain scanning. PTSD diagnosis was confirmed in 49 participants.

Effects of calcitonin and calcium medication in treatment of edentulous osteoporotic mandible.

Background/aim: In addition to damage of the bones that support the remaining teeth, degradation of osteoporotic oral bones also lead to a consequent reduction of supporting tissues and the loss of dentures retention. The aim of this study was to assess the clinical and radiographic outcomes following injection of a calcitonin and calcium solution into the buccal aspects of edentulous mandibles.

Methods: The experimental group of 67 edentulous patients diagnosed with osteoporosis, and the control group of 19 nonosteoporotic edentulous patients were treated with the calcitonin and calcium once solution per month.

Influence of balanced occlusion in complete dentures on the decrease in the reduction of an edentulous ridge.

Background/aim: Balanced occlusal arrangement of artificial teeth and balanced occlusion is a specific type of occlusion that preserves the stability of complete dentures. Balanced occlusion comprises realization of tooth contacts at the working side as well as at the balancing side, at the same time. The aim of this study was to assess the influence of balanced occlusal arrangement of artificial teeth on the decrease in reduction of edentulous alveolar ridge.

Radiographic changes in alveolar bone height on overdenture abutments: a longitudinal study.

Objective: Stabilisation of partial dentures is an important part of prosthodontic treatment, particularly in patients with an excessive reduction in alveolar bone supporting their abutment teeth. In these cases, overdenture prostheses are one possible treatment choice.

Background: The aim of this study was to evaluate the effects of overdentures on the condition of alveolar bone of the remaining teeth, and to evaluate the overdenture concept in the prosthetic treatment of partially edentulous patients.

Roentgencraniometric indicators of the position of the occlusal plane in natural and artificial dentitions.

The angular relationship between the occlusal plane and six variants of Camper's plane used in clinical practice were investigated on 41 lateral cephalometric radiographs. The line A-T1, connecting the lower border of the ala with the upper border of the tragus is recommended in establishing the occlusal plane in patients with a Skeletal Class 2 jaw relationship, the A-T2, running through the middle of the tragus, in patients with a Skeletal Class 1, and the line A-T3, running through the lower border of the tragus in patients with the Skeletal Class 3 jaw relationship.

A comparative study of the chewing cycles of dentate and denture-wearing subjects.

Patterns of incisal point movements during habitual and unilateral chewing of 35 complete denture wearers and a control group of 35 dentate subjects were analyzed using a Sirognathograph. The graphs of the lengths, angles, and envelopes of motion made during habitual chewing cycles by complete denture wearers were analyzed and found to be similar to those of dentate subjects. However, when analyzing the graphs of separate chewing cycles at the beginning of unilateral chewing, significant differences in the movement performance were found using the same parameters.

Graphic assessment of interincisal point movements during chewing of hard and soft foods.

Interincisal point movements in 35 healthy, dentate subjects were investigated with an electrognathic apparatus. The main focus of the study was to find the average values of determined point graphic assessment in frontal and sagittal planes during chewing of hard and soft foods. However, as this was insufficient to obtain information on areas where occlusal contacts were reached, border movement envelopes were also recorded to obtain indirect information in connection to the previous task.

[Electrognathography and its application in dentistry].

The problem of spatial recording and analysing of mandibular movements was always of interest in dentistry. The permanent development of new technologies has resulted in a wide range of various methods and measuring systems for recording mandibular movements. However, only some of them have fulfilled a greater number of evaluation demands of modern measuring systems, which permit their industrial production.

[Recording of masticatory cycles by electrognathographic method].

Electrognathographic method of the three-dimensional recording of mandibular movements can be successfully used in the analysis of spatial shifting of interincisal point during mastication. Investigations carried out in the world by a sirognathograph (Sirognathograph, Siemens A.G.