252 research outputs found

    Caveolin-3 differentially orchestrates cholinergic and serotonergic constriction of murine airways

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    The mechanisms of controlling airway smooth muscle (ASM) tone are of utmost clinical importance as inappropriate constriction is a hallmark in asthma and chronic obstructive pulmonary disease. Receptors for acetylcholine and serotonin, two relevant mediators in this context, appear to be incorporated in specialized, cholesterol-rich domains of the plasma membrane, termed caveolae due to their invaginated shape. The structural protein caveolin-1 partly accounts for anchoring of these receptors. We here determined the role of the other major caveolar protein, caveolin-3 (cav-3), in orchestrating cholinergic and serotonergic ASM responses, utilizing newly generated cav-3 deficient mice. Cav-3 deficiency fully abrogated serotonin-induced constriction of extrapulmonary airways in organ baths while leaving intrapulmonary airways unaffected, as assessed in precision cut lung slices. The selective expression of cav-3 in tracheal, but not intrapulmonary bronchial epithelial cells, revealed by immunohistochemistry, might explain the differential effects of cav-3 deficiency on serotonergic ASM constriction. The cholinergic response of extrapulmonary airways was not altered, whereas a considerable increase was observed in cav-3â -/- intrapulmonary bronchi. Thus, cav-3 differentially organizes serotonergic and cholinergic signaling in ASM through mechanisms that are specific for airways of certain caliber and anatomical position. This may allow for selective and site-specific intervention in hyperreactive states

    Phosphocholine – an agonist of metabotropic but not of ionotropic functions of alpha9-containing nicotinic acetylcholine receptors

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    We demonstrated previously that phosphocholine and phosphocholine-modified macromolecules efficiently inhibit ATP-dependent release of interleukin-1beta from human and murine monocytes by a mechanism involving nicotinic acetylcholine receptors (nAChR). Interleukin-1beta is a potent pro-inflammatory cytokine of innate immunity that plays pivotal roles in host defence. Control of interleukin-1beta release is vital as excessively high systemic levels cause life threatening inflammatory diseases. In spite of its structural similarity to acetylcholine, there are no other reports on interactions of phosphocholine with nAChR. In this study, we demonstrate that phosphocholine inhibits ion-channel function of ATP receptor P2X7 in monocytic cells via nAChR containing alpha9 and alpha10 subunits. In stark contrast to choline, phosphocholine does not evoke ion current responses in Xenopus laevis oocytes, which heterologously express functional homomeric nAChR composed of alpha9 subunits or heteromeric receptors containing alpha9 and alpha10 subunits. Preincubation of these oocytes with phosphocholine, however, attenuated choline-induced ion current changes, suggesting that phosphocholine may act as a silent agonist. We conclude that phophocholine activates immuno-modulatory nAChR expressed by monocytes but does not stimulate canonical ionotropic receptor functions

    Antiproliferative Activity of Natural Flavonoid Fustin Isolated from the Heartwood of Cotinus Coggygria Scop. Against Breast and Colon Cancer Cell Lines

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    Background and objective: Cotinus coggygria Scop. is a valuable medicinal plant species with pronounced pharmacological potential due to its numerous biological activities. The herb is characterized by a high content of polyphenols among which is fustin. The anticancer activities of fustin, however, are extremely weakly studied. The aim of the present study was to investigate the in vitro antiproliferative potential of fustin isolated from the heartwood of C. coggygria against cell lines originating from two of the most common cancer types – breast (MDA-MB-231 and MCF7), and colon cancer (Colon 26). Materials and methods: Cell growth inhibitory properties of fustin were examined by MTT assay. Subsequently, phase-contrast and fl uorescence microscopy analysis as well as colonyforming assay were carried out on the most sensitive to the cytostatic action of the fustin cell line. Results: The obtained results showed that fustin reduced the proliferation of all studied cell lines. The highest cytostatic eff ect was registered towards breast cancer MDA-MB-231 cells with a half maximal inhibitory concentration (IC50) value of 56.02 μg/ ml followed by colon cancer cells with an IC50 of 78.07 μg/ml. MCF7 cell proliferation was least aff ected with a calculated IC50 of 187.8 μg/ml. Further investigations on breast cancer MDA-MB-231 cells indicated decreased density of cell monolayer and some morphological alterations, signifi cant attenuation in the number of viable cells, and diminished clonogenic ability of cells after fustin exposure. Conclusion: It could be concluded that fustin isolated from the heartwood of medicinal plant C. coggygria possesses marked antiproliferative properties against breast cancer cell line MDA-MB-231 which will be a subject of our more detailed future investigations

    SKELETAL AGE ASSESSMENT IN PATIENTS WITH TRANSVERSE MAXILLARY DEFICIT UNDERGOING RAPID MAXILLARY EXPANSION

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    Aim: The study was governed by two main goals: 1) To assess the skeletal maturation of young patients who were undergoing orthodontic treatment with rapid maxillary expansion; 2) To compare their chronological age with their skeletal maturation stage. Material and methods: Lateral cephalometric radiographs of 74 patients were randomly selected and analyzed. The sample included 51 girls and 23 boys in late mixed and permanent dentition, with an average age of 13.2 (± 2.24) in the range from 9 to 17 years. The assessment of skeletal maturation followed the cervical vertebral maturation (CVM) methods of Baccetti et al. and Lamparski. Results: The results showed 53% consistency and 47% discrepancy between the chronological and skeletal age of the patients. In the age group 9-13.5 years, the discrepancies reached 73.5%. The difference in percentages was statistically significant, p <.001. The discrepancies tended towards higher skeletal age: 80% in the whole sample and 86.25% among patients aged 9 - 13.50 years. The difference between the patients classified in higher and lower stages of skeletal age was statistically significant, p <.001. Conclusion: Chronological age is an unreliable indicator of growth potential in adolescent patients before and after growth spurt. The discrepancy is particularly prominent in patients before growth spurt, where skeletal age suggests a higher level of maturation than predicted by the patients’ chronological age

    Empirical Investigation on Agile Methods Usage: Issues Identified from Early Adopters in Malaysia

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    Agile Methods are a set of software practices that can help to produce products faster and at the same time deliver what customers want. Despite the benefits that Agile methods can deliver, however, we found few studies from the Southeast Asia region, particularly Malaysia. As a result, less empirical evidence can be obtained in the country making its implementation harder. To use a new method, experience from other practitioners is critical, which describes what is important, what is possible and what is not possible concerning Agile. We conducted a qualitative study to understand the issues faced by early adopters in Malaysia where Agile methods are still relatively new. The initial study involves 13 participants including project managers, CEOs, founders and software developers from seven organisations. Our study has shown that social and human aspects are important when using Agile methods. While technical aspects have always been considered to exist in software development, we found these factors to be less important when using Agile methods. The results obtained can serve as guidelines to practitioners in the country and the neighbouring regions

    COMPARISON OF SKELETAL MATURITY AND CHRONOLOGICAL AGE IN BULGARIAN FEMALE AND MALE PATIENTS WITH TRANSVERSE MAXILLARY DEFICIT

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    Aim: The aim of this study was to compare the skeletal and chronological age of adolescent Bulgarian female and male patients with а transverse maxillary deficit in order to establish the level of consistencies and discrepancies within and between the two sexes. Material and methods: The data included lateral cephalometric radiographs of 74 patients, among whom 51 girls and 23 boys. The patients’ ages ranged between 9 and 17 years, with an average age of 13.2 years (±2.24). The assessment of skeletal maturation followed the cervical vertebral maturation (CVM) methods of Baccetti et al. and Lamparski. Comparison of skeletal and chronological age was performed for patients before age spurt and after age spurt within the female and male groups. The two sexes were compared in view of consistencies and discrepancies between chronological and skeletal age. Results: The results showed a statistically lower percentage of consistencies and a higher percentage of discrepancies in patients before age spurt for both sexes. Vice versa, in patients after age spurt consistencies, constituted a statistically higher percentage for both sexes. As a whole, the female patients had a slightly higher percentage of consistency (54%) between chronological and skeletal age than the male patients (48%), but the difference of 6% was not statistically significant p = 0.73. The discrepancies towards a higher skeletal age constituted 83% of the total number of discrepancies among the female patients and 75% of the discrepancies among the male patients. The difference of 8% was not significant, p = 0.56. The mean chronological age of the female and male patients in each CVS stage was very similar. Conclusion: In patients with incomplete skeletal growth, skeletal age corresponds to a higher level of maturation than predicted by the patients’ chronological age in both female and male patients. The two sexes show similar trends of accelerated skeletal maturation without statistically significant differences. Our results differ from previous findings of the existence of sexual dimorphism in skeletal age maturation

    Bacterial rotary export ATPases are allosterically regulated by the nucleotide second messenger cyclic-di-GMP

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    The widespread second messenger molecule cyclic di-GMP (cdG) regulates the transition from motile and virulent lifestyles to sessile, biofilm-forming ones in a wide range of bacteria. Many pathogenic and commensal bacterial-host interactions are known to be controlled by cdG signaling. Although the biochemistry of cyclic dinucleotide metabolism is well understood, much remains to be discovered about the downstream signaling pathways that induce bacterial responses upon cdG binding. As part of our ongoing research into the role of cdG signaling in plant-associated Pseudomonas species, we carried out an affinity capture screen for cdG binding proteins in the model organism Pseudomonas fluorescens SBW25. The flagella export AAA+ ATPase FliI was identified as a result of this screen and subsequently shown to bind specifically to the cdG molecule, with a KD in the low micromolar range. The interaction between FliI and cdG appears to be very widespread. In addition to FliI homologs from diverse bacterial species, high affinity binding was also observed for the type III secretion system homolog HrcN and the type VI ATPase ClpB2. The addition of cdG was shown to inhibit FliI and HrcN ATPase activity in vitro. Finally, a combination of site-specific mutagenesis, mass spectrometry, and in silico analysis was used to predict that cdG binds to FliI in a pocket of highly conserved residues at the interface between two FliI subunits. Our results suggest a novel, fundamental role for cdG in controlling the function of multiple important bacterial export pathways, through direct allosteric control of export ATPase proteins
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