63 research outputs found
Ccl2 and Ccl3 Mediate Neutrophil Recruitment via Induction of Protein Synthesis and Generation of Lipid Mediators
Objective: Although the chemokines monocyte chemoattractant protein-1 (Ccl2/JE/MCP-1) and macrophage inflammatory protein-1α (Ccl3/MIP-1α) have recently been implicated in neutrophil migration, the underlying mechanisms remain largely unclear.
Methods and Results: Stimulation of the mouse cremaster muscle with Ccl2/JE/MCP-1 or Ccl3/MIP-1α induced a significant increase in numbers of firmly adherent and transmigrated leukocytes (>70% neutrophils) as observed by in vivo microscopy. This increase was significantly attenuated in mice receiving an inhibitor of RNA transcription (actinomycin D) or antagonists of platelet activating factor (PAF; BN 52021) and leukotrienes (MK-886; AA-861). In contrast, leukocyte responses elicited by PAF and leukotriene-B4 (LTB4) themselves were not affected by actinomycin D, BN 52021, MK-886, or AA-861. Conversely, PAF and LTB4, but not Ccl2/JE/MCP-1 and Ccl3/MIP-1α, directly activated neutrophils as indicated by shedding of CD62L and marked upregulation of CD11b. Moreover, Ccl2/JE/
MCP-1- and Ccl3/MIP-1α-elicited leakage of fluorescein isothiocyanate dextran as well as collagen IV remodeling within the venular basement membrane were completely absent in neutrophil-depleted mice.
Conclusions: Ccl2/JE/MCP-1 and Ccl3/MIP-1α mediate firm adherence and (subsequent) transmigration of neutrophils via protein synthesis and secondary generation of leukotrienes and PAF, which in turn directly activate neutrophils. Thereby, neutrophils facilitate basement membrane remodeling and promote microvascular leakage
Atrial Natriuretic Peptide Protects against Histamine-Induced Endothelial Barrier Dysfunction in Vivo
Endothelial barrier dysfunction is a hallmark of many severe pathologies, including sepsis or atherosclerosis. The cardiovascular hormone atrial natriuretic peptide (ANP) has increasingly been suggested to counteract endothelial leakage. Surprisingly, the precise in vivo relevance of these observations has never been evaluated. Thus, we aimed to clarify this issue and, moreover, to identify the permeability-controlling subcellular systems that are targeted by ANP. Histamine was used as important pro-inflammatory, permeability-increasing stimulus. Measurements of fluorescein isothiocyanate (FITC)-dextran extravasation from venules of the mouse cremaster muscle and rat hematocrit values were performed to judge changes of endothelial permeability in vivo. It is noteworthy that ANP strongly reduced the histamine-evoked endothelial barrier dysfunction in vivo. In vitro, ANP blocked the breakdown of transendothelial electrical resistance (TEER) induced by histamine. Moreover, as judged by immunocytochemistry and Western blot analysis, ANP inhibited changes of vascular endothelial (VE)-cadherin, β-catenin, and p120ctn morphology; VE-cadherin and myosin light chain 2 (MLC2) phosphorylation; and F-actin stress fiber formation. These changes seem to be predominantly mediated by the natriuretic peptide receptor (NPR)-A, but not by NPR-C. In summary, we revealed ANP as a potent endothelial barrier protecting agent in vivo and identified adherens junctions and the contractile apparatus as subcellular systems targeted by ANP. Thus, our study highlights ANP as an interesting pharmacological compound opening new therapeutic options for preventing endothelial leakage
Определение размеров свободного внутреннего пространства трансмиссии геохода с гидроцилиндрами
Development and Testing of the Dysmenorrhea Symptom Interference (DSI) Scale
Dysmenorrhea affects most reproductive-age women and increases the risk of future pain. To evaluate dysmenorrhea interventions, validated outcome measures are needed. In this two-phase study, we developed and tested the dysmenorrhea symptom interference scale. During the scale-development phase (n = 30), we created a nine-item scale based on qualitative data from cognitive interviews. During the scale-testing phase (n = 686), we evaluated reliability, validity, and responsiveness to change. The scale measures how dysmenorrhea symptoms interfere with physical, mental, and social activities. Internal consistency was strong with Cronbach's α > 0.9. Test-retest reliability was acceptable (r = 0.8). The scale showed satisfactory content validity, construct validity (supported by confirmatory factor analysis), concurrent validity, and responsiveness to change. The minimally important difference was 0.3 points on a scale with a possible total score ranging from 1 to 5. This new psychometrically sound scale can be used in research and clinical practice to facilitate the measurement and management of dysmenorrhea
Математическая модель нагрева частиц порошкового материала при нанесении плазменных газотермических покрытий
Measuring research mistrust in adolescents and adults: Validity and reliability of an adapted version of the Group-Based Medical Mistrust Scale
Mistrust of health care providers among persons of color is a significant barrier to engaging them in research studies. Underrepresentation of persons of color is particularly problematic when the health problem under study disproportionately affects minoritized communities. The purpose of this study was to test the validity and reliability of an abbreviated and adapted version of the Group Based Medical Mistrust Scale. The GBMMS is a 12-item scale with three subscales that assess suspicion, experiences of discrimination, and lack of support in the health care setting. To adapt for use in the research setting, we shortened the scale to six items, and replaced "health care workers" and "health care" with "medical researchers" and "medical research," respectively. Using panelists from a market research firm, we recruited and enrolled a racially and ethnically diverse sample of American adults (N = 365) and adolescents aged 14-17 (N = 250). We administered the adapted scale in a web-based survey. We used Cronbach's alpha to evaluate measure internal reliability of the scale and external factor analysis to evaluate the relationships between the revised scale items. Five of the six items loaded onto a single factor, with (α = 0.917) for adolescents and (α = 0.912) for adults. Mean scores for each item ranged from 2.5-2.9, and the mean summary score (range 6-25) was 13.3 for adults and 13.1 for adolescents. Among adults, Black respondents had significantly higher mean summary scores compared to whites and those in other racia/ethnic groups (p<0.001). There was a trend toward significance for Black adolescents as compared to white respondents and those in other racial/ethnic groups (p = 0.09). This five-item modified version of the GBMMS is reliable and valid for measuring research mistrust with American adults and adolescents of diverse racial and ethnic identities
Optimized dispersion of nanoparticles for biological in vitro and in vivo studies
Background: The aim of this study was to establish and validate a practical method to disperse nanoparticles in physiological solutions for biological in vitro and in vivo studies. Results: TiO(2) (rutile) dispersions were prepared in distilled water, PBS, or RPMI 1640 cell culture medium. Different ultrasound energies, various dispersion stabilizers (human, bovine, and mouse serum albumin, Tween 80, and mouse serum), various concentrations of stabilizers, and different sequences of preparation steps were applied. The size distribution of dispersed nanoparticles was analyzed by dynamic light scattering and zeta potential was measured using phase analysis light scattering. Nanoparticle size was also verified by transmission electron microscopy. A specific ultrasound energy of 4.2 x 10(5) kJ/m(3) was sufficient to disaggregate TiO(2) (rutile) nanoparticles, whereas higher energy input did not further improve size reduction. The optimal sequence was first to sonicate the nanoparticles in water, then to add dispersion stabilizers, and finally to add buffered salt solution to the dispersion. The formation of coarse TiO(2) (rutile) agglomerates in PBS or RPMI was prevented by addition of 1.5 mg/ml of human, bovine or mouse serum albumin, or mouse serum. The required concentration of albumin to stabilize the nanoparticle dispersion depended on the concentration of the nanoparticles in the dispersion. TiO(2) (rutile) particle dispersions at a concentration lower than 0.2 mg/ml could be stabilized by the addition of 1.5 mg/ml albumin. TiO(2) (rutile) particle dispersions prepared by this method were stable for up to at least 1 week. This method was suitable for preparing dispersions without coarse agglomerates (average diameter < 290 nm) from nanosized TiO(2) (rutile), ZnO, Ag, SiO(x), SWNT, MWNT, and diesel SRM2975 particulate matter. Conclusion: The optimized dispersion method presented here appears to be effective and practicable for preparing dispersions of nanoparticles in physiological solutions without creating coarse agglomerates
Система электронного декларирования товаров в таможенных органах
Актуальность выбранной темы дипломной работы обусловлена тем, что система электронного декларирования успешно внедрилась в деятельность таможенных органов. Но при этом постоянно требует совершенствования, так как необходим определенный уровень обработки, хранения информации и качественного межведомственного взаимодействия. Объектом исследования является система электронного декларирования товаров. Целью - выявление комплексных характеристик функциональных возможностей системы электронного декларирования РФ.The relevance of the chosen topic that the electronic declaration system successfully entered the activities of the customs authorities. But at the same time, it constantly requires improvement, since it requires a specific level of processing, information storage and qualitative interdepartmental interaction. The object of research is the system of electronic declaration of goods. The goal is to identify complex characteristics of the functional capabilities of the electronic declaration system of the Russian Federation
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