Calcium homeostasis and role of ryanodine receptor type 1 (RyR1) in immune cells

Ryanodine receptors are intracellular Ca2+ release channels located in the membrane of the Endoplasmatic/Sarcoplasmatic Reticulum. Ryanodine receptor 1 isoform is preferentially expressed in skeletal muscle where it is responsible for release of Ca2+ from the SR, an event that leads to muscle contraction. Point mutations in the gene encoding ryanodine receptor 1 have been linked to disease such as Malignant Hyperthermia, Central core disease and Multi-minicore disease. Malignant Hyperthermia is a pharmacogenetic disorder with autosomal dominant inheritance and abnormal Ca2+ homeostasis in skeletal muscle in response to triggering agents. In susceptible individuals, a malignant hyperthermia crisis may be triggered by commonly used halogenated anaesthetics (halothane, isoflurane) or muscle relaxants (succhinylcholine). The main symptoms are hypermetabolism and muscle rigidity. Without treatment, death would occur in more than 80% of cases. Although a genetic-chip based diagnostic approach is under development, the invasive in vitro contracture test remains the “gold standard” to diagnose this disorder. Central core disease is a slowly progressive myopathy characterized by muscle weakness and hypotonia. Central core disease is characterized histologically by the presence of central cores running along longitudinal axis of the muscle fiber. Multi-minicore disease disease is a more severe, rare, autosomal recessive myopathy characterized histologically by the presence of multi-minicores in only a small number of sarcomeres. So far, no effective therapy has been developed to treat muscle weakness in central core disease and multi-minicore disease patients and their diagnosis is difficult on the basis of clinical findings alone. Histological examination of muscle tissue in these diseases is essential. Recent data has shown that ryanodine receptor 1 is also expressed in some areas of the central nervous system as well as in cells of the immune system, specifically B-lymphocytes and dendritic cells. The first part of my thesis focuses on the role of the ryanodine receptor 1 in dendritic cell. We first show that both immature and mature in vitro derived dendritic cells as well as circulating plasmocytoid cells express the ryanodine receptor 1 Ca2+ release channel within the endoplasmatic reticulum. Pharmacological activation of the ryanodine receptor 1 leads to the rapid release of Ca2+ from intracellular stores, and in the presence of sub-optimal concentrations of microbial stimuli, provides synergistic signals resulting in dendritic cell maturation and stimulation of T cell function. Furthermore, we were interested in unravelling more direct roles of this receptor in dendritic cells function. Interestingly, ryanodine receptor 1 activation in dendritic cells causes a very rapid increase in surface expression of major histocompatibility complex II molecules. In order to dissect the physiological route of ryanodine receptor 1 activation in vivo we hypothesized that a possible functional partner of ryanodine receptor 1 in dendritic cells could be, an L-type Ca2+ channel. We were able to show that human dendritic cells express the cardiac isoform of the L-type Ca2+ channel, which acts as a ryanodine receptor 1 functional partner on the plasma membrane of dendritic cells. We show that depolarization of dendritic cells by the addition of potassium chloride activates L-type Ca2+ channels initiating Ca2+ influx and activation of Ca2+ release via ryanodine receptor 1 and that this process could be prevented by nifedipine or ryanodine. Physiologically potassium could be released from dying cells within an inflamed tissue or from T- cells into immunological synapse during dendritic cell T-cell engagement and these events could be possible routes for activation of L-type Ca2+ channel- ryanodine receptor 1 signalling in dendritic cells in vivo. Thus, in vivo, activation of the ryanodine receptor 1 signalling cascade may be important during the early stages of infection, providing the immune system with rapid mechanisms to initiate an early response, facilitating the presentation of antigens to T cells. While continuing our investigation on Ca2+ homeostasis in dendritic cells we noticed that spontaneous Ca2+ oscillations occur in immature dendritic cells but not in dendritic cells stimulated to undergo maturation with lipopolysaccharide or other toll like-receptor agonists. We investigated the mechanism and role of spontaneous Ca2+ oscillations in immature dendritic cells and found that they are mediated by the inositol-1,4,5-trisphosphate receptor since they were blocked by pre-treatment of cells with the inositol-1,4,5-trisphosphate receptor antagonist Xestospongin C and 2-Aminoethoxydiphenyl borate. A component of the Ca2+ signal is also due to influx from the extracellular environment. As to the biological function of these high frequency oscillations, our results indicate that they are associated with the translocation of a Ca2+ dependent transcription factor (nuclear factor of activated T-cells) into the nucleus of immature dendritic cells. In fact, once the Ca2+ oscillations are blocked with the 2-aminoethoxydiphenyl borate or by treating cells with lipopolysaccharide, nuclear factor of activated T-cells remains cytoplasmic. The results from the first part of my thesis provide novel insights into the physiology of dendritic cells, role of ryanodine receptor 1 signaling and Ca2+ as an important second messenger in these cells. The second aim of my thesis deals with functional properties of ryanodine receptor 1 carrying mutations linked to neuromuscular disorders, which is important from diagnostic point of view but also to understand the basic pathophysiological mechanism leading to these different diseases. Since functional ryanodine receptors 1 are expressed in B-lymphocytes we investigated Ca2+ homeostasis in B-lymphocytes transformed with Epstein Barr virus from patients carrying the mutation linked to malignant hyperthermia and healthy donors. In the first study from the Swiss population we investigated four novel mutations found in malignant hyperthermia susceptible pedigrees: (p.D544Y, p.R2336H, p.E2404K and p.D2730G). We found that the resting Ca2+ levels were significantly higher in cells from all four mutations bearing individuals compared to controls. These four mutations were also found to significantly affect either 4-chloro-m-cresol or caffeine dose response curves suggesting higher sensitivity of ryanodine receptor 1 to pharmacological activation in patients carrying these mutations. In the second study we examined patients from the Swedish population carrying five different novel mutations (p.E1058K, p.R1679H, p.H382N, p.K1393R and p.R2508G). The first 4 patients had serious malignant hyperthermia clinical reactions and thereafter have tested by the in vitro contracture test and classified as malignant hyperthermia susceptible; the patient with the fifth mutation, p.Arg2508Gly, had been diagnosed as a central core disease. In this study as well functional studies were performed on Epstein Barr virus transformed B-lymphocytes from patients carrying mutations and healthy donors. Our results from the Swedish population suggest that ryanodine receptor 1 mutations also lead to abnormal Ca2+ homeostasis. Results from these and other studies support the use of Epstein Barr virus transformed -B-lymphocytes as an alternative, non-invasive, protocol for the diagnosis and the functional proof that a mutation in the ryanodine receptor causes alterations in Ca2+ homeostasis. This is a pre-requisite for the molecular diagnosis of malignant hyperthermia. These results also provide new concepts for the treatment of muscular pathologies involving mutations in ryanodine receptor 1

Synchronising effect of planetary resonance

This article investigates and demonstrates the combined effect from two major planets at the centre of the Solar system. Both gravitational and magnetic effects are considered as possible sources of solar activity synchronisation

Army Information Technology Procurement: a Business Process Analysis

This thesis presents a business process analysis of the Army\u27s ICT procurement system. The research identified several inefficiencies and proposes several potential solutions. the contributions of this research include a unified taxonomy, a method to prioritize requests, and system architecture products for development of an automated and sustainable collaboration interface for the CIO/G6 to streamline their IT acquisition process. Development of a centralized system would reduce waste in the request process from submission to formal accounting, hasten the movement of requests between stakeholders, maintain a digital signature authorization for each approval authority, provide a reporting database to recognize reprogramming thresholds, and deliver relevant metrics and analysis to help inform the Army\u27s IT resourcing decisions

Scattering of the UHECR at small pitch angle by damped plasma waves

In spite a lot of theoretical and experimental effort that has been achieved in ultra-high energy cosmic ray (UHECR) scattering research in last few decades, some questions remain unanswered, or partially answered. Two of them, that will be in the focus of this paper are: possible source of UHECRs and the acceleration mechanism of cosmic rays beyond PeV energies. Small pitch-angle scattering of UHECRs and possible confinement has been investigated using quasilinear theory in order to analytically calculate pitch-angle Fokker-Planck coefficient. CR particles resonantly interact with oblique low frequency damped waves. We show that the resonance function is broadened due to damping effects and this result is compared with the nonlinear broadening. Unlike the case of purely parallel (or antiparallel) propagating waves in slab turbulence, the presence of the compressive magnetic field component of oblique fast-mode waves allows the cosmic ray particles to resonantly interact with these waves through the n = 0 resonance, together with gyroresonance, which strongly influence the Hillas limit. The derived results can be used to compute the parallel mean free path for all forms of the turbulence spectrum; it has been applied on the transport and propagation of CRs close to ultra-high energies in the Galaxy. An accurate understanding of particle acceleration in astrophysical sources could help to interpret eventual transition from Galactic to extragalactic origin of cosmic rays, if any, and the shape of the UHECR spectrum at the highest energies

Branded applications - Function triumphs Brand? -An exploratory study of branded applications’ role in the brand building process

Abstract Title: Branded applications - Function triumphs Brand? -An exploratory study of branded applications’ role in the brand building process Date of the Seminar: 2013.05.29 Course: BUSN29, Degree project in Global marketing Authors: Vukcevic, Lidia and Willgottson, Malin Supervisor: Elg, Ulf Keywords: Brand building process, High/low involvement brands, Mobile marketing, Branded applications. Thesis purpose: The primary purpose of this thesis is to explore the role of branded applications in the different steps of the brand building process. Further, an investigation of whether this differs between a high and low involvement brand will be conducted from both a consumer and managerial perspective. Methodology: Given the aim of this study a qualitative method was conducted, which consisted of three in-depth interviews and four focus groups. The in-depth interviews were conducted with managers from Kungsörnen and Nespresso. Theoretical perspective: This thesis is based on theory regarding the brand building process from the consumer perspective as well as theory around mobile marketing and applications. An extended framework of Melin’s (1997) model of the brand building process and Pelsmacker, Geuens and Bergh’s (2010) e-communication framework served as the basis for the empirical data collection. Empirical data: The empirical data has been collected through in-depth interviews conducted in-person with Nespresso and by telephone with Kungsörnen. To gain understanding of how consumer view mobile applications four focus groups were executed. Conclusion: The research reveals that since consumers have accepted mobile applications and do not see it as a marketing tool, marketers can exploit this new communication channel to strengthen the brand. By creating an application that makes the consumer engage with the brand they have the ability to create awareness and positive attitudes towards the brand. Hence, by using mobile applications as a complement to other communication channels, this study shows that branded applications have a primary role during the brand engagement and brand awareness phase of the brand building process. If the marketers manage to achieve engagement and awareness, it can in turn lead to more loyal consumers and brand advocacy

Morphometric characteristics of the optic canal and the optic nerve

Background: The optic nerve (ON), a major component of the visual system, is divided into four segments: the intrabulbar (IB), the intraorbital (IO), the intraca- nalicular (ICn) and the intracranial (ICr). The ICr ends with the two nerves partially decussating in the optic chiasm (OCh). The purpose of this study is to provide a detailed description of the dimensions of the OC (the diameter and the surface area of its foramina and the central segment, as well as the length of the OC and the thickness of its walls) as well as the ON (the length of the ON segments, the diameter of the ICn segment of the ON, the angle of decussation in the OCh, as well as the distance between the two ON at the cranial foramen of the OC).  Materials and methods: The acquired data was then used to estimate the volu- me of the OC and the ICn segment of the ON. The morphometric research was performed on 25 cadavers (17 male and 8 female) and 30 skulls.  Results: The surface area of the central segment of the OC was significantly smaller than the cranial foramen (p = 0.02) and the orbital foramen (p = 0.009). The inferior wall of the OC was significantly shorter than the other OC walls (p < 0.0001). The IO segment of the ON was the longest, where the difference to the ICn and ICr was statistically significant (p < 0.0001). The surface area of the ON at the cranial foramen was significantly larger than the surface area at the central segment of the OC (p = 0.02) and orbital foramen (p < 0.0001). The difference between the surface areas of the ON at the orbital foramen and the central segment of the OC was also statistically significant (p = 0.01). The estimated volume of the OC was calculated to be 190.72 mm3, and the volume of the ICn segment of the ON was estimated to be 50.25 mm3.  Conclusions: It is absolutely crucial to open the central segment of the OC when decompressing the ON, due to the narrowing of the OC in this segment.

A multilevel control system for the large space telescope

A multilevel scheme was proposed for control of Large Space Telescope (LST) modeled by a three-axis-six-order nonlinear equation. Local controllers were used on the subsystem level to stabilize motions corresponding to the three axes. Global controllers were applied to reduce (and sometimes nullify) the interactions among the subsystems. A multilevel optimization method was developed whereby local quadratic optimizations were performed on the subsystem level, and global control was again used to reduce (nullify) the effect of interactions. The multilevel stabilization and optimization methods are presented as general tools for design and then used in the design of the LST Control System. The methods are entirely computerized, so that they can accommodate higher order LST models with both conceptual and numerical advantages over standard straightforward design techniques

Bilateral anatomic variation in the relation of the upper trunk of the brachial plexus to the anterior scalene muscle

The brachial plexus represents a field of many anatomical variations with impor- tant clinical implications, especially in the diagnosis and treatment of the thoracic outlet syndrome (TOS). The case described in this paper presented a novel bilateral variation in the relation of the upper trunk of the brachial plexus to the anterior scalene muscle. The ventral rami of the C5 and C6 spinal nerves perforated the anterior scalene muscle simultaneously through a common opening, and joined to form the upper trunk. Previous literature reports described variations of the brachial plexus and the scalene muscles, as well as the embryological basis for their presence. The case reported herein helps to improve the comprehension of the TOS, as well as the diagnostic and therapeutical approach to this syndrome