135 research outputs found

    Использование корректного нормирования статистических данных в кластерном анализе

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    The fabrication of microchannels and self-assembled nanostructures in the volume of sapphire was performed by femtosecond laser irradiation followed by chemical etching with aqueous solution of HF acid. Depending on the focusing conditions self-organized nanostructures or elliptical microchannels are produced. While the dimensions in two directions are on a micro- respectively nanoscale, feature lengths of up to 1 mm are achieved. This comes out to aspect ratios of more than 1000. This fabrication technique is potentially usable for photonic crystal based integrated optical elements or microfluidic devices for applications in life science, biology or chemistry

    The Effects of Music on Mood and Perception of a Visual Stimulus

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    We examined the influence of music on mood by instructing 81 undergraduate students to complete the Multiple Affect Adjective Check List–Revised (MAACLR) both before and after watching a 15-min video that was or was not paired with a piece of music. The 2 music categories were pleasant or depressing. Participants from the depressing group experienced a drop in positive affect, whereas participants from the pleasant group showed an increase on this measure. Men from the pleasant group had the highest pretreatment and lowest post treatment anxiety scores, whereas the women displayed no change in anxiety. The results indicate that music has only a slight impact on mood

    Einsatz bioanalytischer Systeme bei der industriellen Produktion von Pharmaaminosäuren

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    Aminosäuren finden in den verschiedensten Bereichen vielfältigen Einsatz. Hauptanwendungsgebiete sind die Nahrungsmittel- (50%), Futtermittel (30%)- und pharmazeutische (20%) Industrie. In der pharmazeutischen Industrie werden Aminosäuren höchster Reinheit benötigt. Ein sehr wichtiges Beispiel ist die Verwendung für prä- oder postoperative parenterale Ernährung. In der Kosmetikindustrie dienen Aminosäuren als Ausgangssubstanzen für die Herstellung hochwertiger Hautcremes. Für die Gewinnung von Aminosäuren stehen diverse großtechnische Verfahren zur Verfügung: die Extraktion aus nachwachsenden Rohstoffen, die fermentative Gewinnung, die chemische Synthese und die Biotransformation. Über diese Verfahren wird eine geschätzte Jahresproduktion von weltweit ca. 3. Mrd. Tonnen hergestellt. Bei der AMINO GmbH werden Aminosäuren für den pharmazeutischen Markt aus nachwachsenden Rohstoffen wie Zuckerrübenmelasse über chromatographische Verfahren und Biotransformationen (enzymatische Katalyse) gewonnen. Hierbei ist eine On-line-Prozesskontrolle unabdingbar. Durch die optimierte Kontrolle und Führung des Bioprozesses können Ressourcen eingespart werden. Daraus ergeben sich direkt Umweltentlastungen und Kostenersparnisse. Mit den bisher erzielten Ergebnissen kann eine 20% höhere Produktkonzentration erreicht werden. Dieses entspricht – gerechnet auf die nachfolgenden Aufarbeitungsschritte – einer Ersparnis von 200 bis 300 t Dampf pro Jahr (20% der Produkt spezifischen Energiekosten). Ebenfalls einsparen lassen sich bis zu 2000 m3 Abwasser (entsprechend 0,4 t COD) pro Jahr. Letztendlich ist es das Ziel mit Hilfe der bioanalytischen Verfahren pro Jahr 3,5 t Serin und 0,5 t Indol durch eine 30% höhere Produktausbeute einsparen zu können. Es zeigt sich somit, dass der Einsatz moderner bioanalytischer Verfahren wie der 2-D-Fluoreszenzspektroskopie durchaus zu einer Verbesserung der ökonomischen als auch der ökologischen Faktoren eines industriellen Prozesses führen kann

    Ion access pathway to the transmembrane pore in P2X receptor channels

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    P2X receptors are trimeric cation channels that open in response to the binding of adenosine triphosphate (ATP) to a large extracellular domain. The x-ray structure of the P2X4 receptor from zebrafish (zfP2X4) receptor reveals that the extracellular vestibule above the gate opens to the outside through lateral fenestrations, providing a potential pathway for ions to enter and exit the pore. The extracellular region also contains a void at the central axis, providing a second potential pathway. To investigate the energetics of each potential ion permeation pathway, we calculated the electrostatic free energy by solving the Poisson-Boltzmann equation along each of these pathways in the zfP2X4 crystal structure and a homology model of rat P2X2 (rP2X2). We found that the lateral fenestrations are energetically favorable for monovalent cations even in the closed-state structure, whereas the central pathway presents strong electrostatic barriers that would require structural rearrangements to allow for ion accessibility. To probe ion accessibility along these pathways in the rP2X2 receptor, we investigated the modification of introduced Cys residues by methanethiosulfonate (MTS) reagents and constrained structural changes by introducing disulfide bridges. Our results show that MTS reagents can permeate the lateral fenestrations, and that these become larger after ATP binding. Although relatively small MTS reagents can access residues in one of the vestibules within the central pathway, no reactive positions were identified in the upper region of this pathway, and disulfide bridges that constrain movements in that region do not prevent ion conduction. Collectively, these results suggest that ions access the pore using the lateral fenestrations, and that these breathe as the channel opens. The accessibility of ions to one of the chambers in the central pathway likely serves a regulatory function

    The role of P2X7 in pain and inflammation

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    The P2X7 purinoceptor is unique amongst the P2X receptor family in that its activation is able to stimulate the release of mature, biologically active interleukin-1β (IL-1β), as well as a variety of other proinflammatory cytokines. Coupled with the predominate localisation of this receptor to immunocytes of haemopoetic origin, this receptor is an obvious candidate to play a major and pivotal role in processes of pain and inflammation. Using genetically modified animals that lack the P2X7 receptor, several investigators have shown that these mice do indeed demonstrate a blunted inflammatory response, and fail to develop pain following both inflammatory and neuropathic insult. These animals also show altered cytokine production in response to inflammatory stimulus, which is far broader than merely modulation of IL-1β release. In this short article, we review the role of the P2X7 receptor in modulating the release of cytokines and other mediators, and discuss the findings made from P2X7 receptor-deficient animals. As well as highlighting outstanding questions regarding this intriguing receptor, we also speculate as to the potential therapeutic benefit of P2X7 receptor modulation

    P2X7 Receptor and Caspase 1 Activation Are Central to Airway Inflammation Observed after Exposure to Tobacco Smoke

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    Chronic Obstructive Pulmonary Disease (COPD) is a cigarette smoke (CS)-driven inflammatory airway disease with an increasing global prevalence. Currently there is no effective medication to stop the relentless progression of this disease. It has recently been shown that an activator of the P2X7/inflammasome pathway, ATP, and the resultant products (IL-1β/IL-18) are increased in COPD patients. The aim of this study was to determine whether activation of the P2X7/caspase 1 pathway has a functional role in CS-induced airway inflammation. Mice were exposed to CS twice a day to induce COPD-like inflammation and the role of the P2X7 receptor was investigated. We have demonstrated that CS-induced neutrophilia in a pre-clinical model is temporally associated with markers of inflammasome activation, (increased caspase 1 activity and release of IL-1β/IL-18) in the lungs. A selective P2X7 receptor antagonist and mice genetically modified so that the P2X7 receptors were non-functional attenuated caspase 1 activation, IL-1β release and airway neutrophilia. Furthermore, we demonstrated that the role of this pathway was not restricted to early stages of disease development by showing increased caspase 1 activation in lungs from a more chronic exposure to CS and from patients with COPD. This translational data suggests the P2X7/Inflammasome pathway plays an ongoing role in disease pathogenesis. These results advocate the critical role of the P2X7/caspase 1 axis in CS-induced inflammation, highlighting this as a possible therapeutic target in combating COPD

    The absence of P2X7 receptors (P2rx7) on non-haematopoietic cells leads to selective alteration in mood-related behaviour with dysregulated gene expression and stress reactivity in mice

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    The purpose of this study was to explore how genetic deletion and pharmacological antagonism of the P2X7 receptor (P2rx7) alter mood-related behaviour, gene expression and stress reactivity in the brain. The forced swim test (FST), tail suspension test (TST) and amphetamine-induced hyperlocomotion (AH) tests were used in wild-type (P2rx7+/+) and P2rx7-deficient (P2rx7-/-) mice. Biogenic amine levels were analysed in the amygdala and striatum, adrenocorticotropic hormone (ACTH) and corticosterone levels were measured in the plasma and pituitary after restraint stress. Chimeric mice were generated by bone marrow transplantation. A whole genome microarray analysis with real-time polymerase chain reaction validation was performed on the amygdala. In the absence of P2rx7s decreased behavioural despair in the FST, reduced immobility in the TST and attenuated amphetamine-induced hyperactivity were detected. Basal norepinephrine levels were elevated in the amygdala, whereas stress-induced ACTH and corticosterone responses were alleviated in P2rx7-/- mice. Sub-acute treatment with the selective P2rx7 antagonist, Brilliant Blue G, reproduced the effect of genetic deletion in the TST and AH test in P2rx7+/+ but not P2rx7-/- mice. No change in behavioural phenotype was observed in chimeras lacking the P2rx7 in their haematopoietic compartment. Whole genome microarray analysis indicated a widespread up- and down-regulation of genes crucial for synaptic function and neuroplasticity by genetic deletion. Here, we present evidence that the absence of P2rx7s on non-haematopoietic cells leads to a mood-stabilizing phenotype in several behavioural models and suggest a therapeutic potential of P2rx7 antagonists for the treatment of mood disorders

    Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

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    <p>Abstract</p> <p>Background</p> <p>The study tested the hypothesis that apoptosis can prevent and control growth of neoplastic cells. Previous studies in-vitro have shown that the pro-apoptotic P2X<sub>7 </sub>receptor regulates growth of epithelial cells. The specific objective of the present study was to understand to what degree the P2X<sub>7 </sub>system controls development and growth of skin cancer in vivo, and what cellular and molecular mechanisms are involved in the P2X<sub>7 </sub>action.</p> <p>Methods</p> <p>Skin neoplasias in mice (papillomas, followed by squamous spindle-cell carcinomas) were induced by local application of DMBA/TPA. Experiments in-vitro utilized cultured epidermal keratinocytes generated from wild-type or from P2X<sub>7</sub>-null mice. Assays involved protein immunostaining and Western blots; mRNA real-time qPCR; and apoptosis (evaluated in situ by TUNEL and quantified in cultured keratinocytes as solubilized DNA or by ELISA). Changes in cytosolic calcium or in ethidium bromide influx (P2X<sub>7 </sub>pore formation) were determined by confocal laser microscopy.</p> <p>Results</p> <p>(a) Co-application on the skin of the P2X<sub>7 </sub>specific agonist BzATP inhibited formation of DMBA/TPA-induced skin papillomas and carcinomas. At the completion of study (week 28) the proportion of living animals with cancers in the DMBA/TPA group was 100% compared to 43% in the DMBA/TPA+BzATP group. (b) In the normal skin BzATP affected mainly P2X<sub>7</sub>-receptor – expressing proliferating keratinocytes, where it augmented apoptosis without evoking inflammatory changes. (c) In BzATP-treated mice the degree of apoptosis was lesser in cancer than in normal or papilloma keratinocytes. (d) Levels of P2X<sub>7 </sub>receptor, protein and mRNA were 4–5 fold lower in cancer tissues than in normal mouse tissues. (e) In cultured mouse keratinocytes BzATP induced apoptosis, formation of pores in the plasma membrane, and facilitated prolonged calcium influx. (f) The BzATP-induced apoptosis, pore-formation and augmented calcium influx had similar dose-dependence for BzATP. (g) Pore formation and the augmented calcium influx were depended on the expression of the P2X<sub>7 </sub>receptor, while the BzATP-induced apoptosis depended on calcium influx. (h) The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8.</p> <p>Conclusion</p> <p>(a) P2X<sub>7</sub>-dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b) The P2X<sub>7</sub>-dependent apoptosis is mediated by calcium influx via P2X<sub>7 </sub>pores, and involves the caspase-9 (mitochondrial) pathway. (c) The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X<sub>7 </sub>receptor. (d) Activation of P2X<sub>7</sub>-dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo.</p

    COX-2, CB2 and P2X7-immunoreactivities are increased in activated microglial cells/macrophages of multiple sclerosis and amyotrophic lateral sclerosis spinal cord

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    BACKGROUND: While multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) are primarily inflammatory and degenerative disorders respectively, there is increasing evidence for shared cellular mechanisms that may affect disease progression, particularly glial responses. Cyclooxygenase 2 (COX-2) inhibition prolongs survival and cannabinoids ameliorate progression of clinical disease in animal models of ALS and MS respectively, but the mechanism is uncertain. Therefore, three key molecules known to be expressed in activated microglial cells/macrophages, COX-2, CB2 and P2X7, which plays a role in inflammatory cascades, were studied in MS and ALS post-mortem human spinal cord. METHODS: Frozen human post mortem spinal cord specimens, controls (n = 12), ALS (n = 9) and MS (n = 19), were available for study by immunocytochemistry and Western blotting, using specific antibodies to COX-2, CB2 and P2X7, and markers of microglial cells/macrophages (CD 68, ferritin). In addition, autoradiography for peripheral benzodiazepine binding sites was performed on some spinal cord sections using [3H] (R)-PK11195, a marker of activated microglial cells/macrophages. Results of immunostaining and Western blotting were quantified by computerized image and optical density analysis respectively. RESULTS: In control spinal cord, few small microglial cells/macrophages-like COX-2-immunoreactive cells, mostly bipolar with short processes, were scattered throughout the tissue, whilst MS and ALS specimens had significantly greater density of such cells with longer processes in affected regions, by image analysis. Inflammatory cell marker CD68-immunoreactivity, [3H] (R)-PK11195 autoradiography, and double-staining against ferritin confirmed increased production of COX-2 by activated microglial cells/macrophages. An expected 70-kDa band was seen by Western blotting which was significantly increased in MS spinal cord. There was good correlation between the COX-2 immunostaining and optical density of the COX-2 70-kDa band in the MS group (r = 0.89, P = 0.0011, n = 10). MS and ALS specimens also had significantly greater density of P2X7 and CB2-immunoreactive microglial cells/macrophages in affected regions. CONCLUSION: It is hypothesized that the known increase of lesion-associated extracellular ATP contributes via P2X7 activation to release IL-1 beta which in turn induces COX-2 and downstream pathogenic mediators. Selective CNS-penetrant COX-2 and P2X7 inhibitors and CB2 specific agonists deserve evaluation in the progression of MS and ALS

    Selective P2X7 receptor antagonists for chronic inflammation and pain

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    ATP, acting on P2X7 receptors, stimulates changes in intracellular calcium concentrations, maturation, and release of interleukin-1β (IL-1β), and following prolonged agonist exposure, cell death. The functional effects of P2X7 receptor activation facilitate several proinflammatory processes associated with arthritis. Within the nervous system, these proinflammatory processes may also contribute to the development and maintenance of chronic pain. Emerging data from genetic knockout studies have indicated specific roles for P2X7 receptors in inflammatory and neuropathic pain states. The discovery of multiple distinct chemical series of potent and highly selective P2X7 receptor antagonists have enhanced our understanding of P2X7 receptor pharmacology and the diverse array of P2X7 receptor signaling mechanisms. These antagonists have provided mechanistic insight into the role(s) P2X7 receptors play under pathophysiological conditions. In this review, we integrate the recent discoveries of novel P2X7 receptor-selective antagonists with a brief update on P2X7 receptor pharmacology and its therapeutic potential
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