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81.
82.
Thomas Schmiedinger Georg F. Vogel Oliver Eiter Kristian Pfaller Walter A. Kaufmann Angelika Flörl Karin Gutleben Sabine Schönherr Barbara Witting Thomas W. Lechleitner Hannes‐L. Ebner Thomas Seppi Michael W. Hess 《Traffic (Copenhagen, Denmark)》2013,14(8):886-894
Electrospun nanofibres are an excellent cell culture substrate, enabling the fast and non‐disruptive harvest and transfer of adherent cells for microscopical and biochemical analyses. Metabolic activity and cellular structures are maintained during the only half a minute‐long harvest and transfer process. We show here that such samples can be optimally processed by means of cryofixation combined either with freeze‐substitution, sample rehydration and cryosection‐immunolabelling or with freeze‐fracture replica‐immunolabelling. Moreover, electrospun fibre substrates are equally suitable for complementary approaches, such as biochemistry, fluorescence microscopy and cytochemistry. 相似文献
83.
Agathe Hess Lianchun Yu Isabelle Klein Marine De Mazancourt Gilles Jebrak Hervé Mal Olivier Brugière Michel Fournier Maurice Courbage Gaelle Dauriat Elisabeth Schouman-Clayes Christine Clerici Laurence Mangin 《PloS one》2013,8(10)
Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can contribute to chaos in airflow and reproduces key experimental fMRI findings. 相似文献
84.
S?s Neergaard-Petersen Ramzi Ajjan Anne-Mette Hvas Katharina Hess Sanne B?jet Larsen Steen Dalby Kristensen Erik Lerkevang Grove 《PloS one》2013,8(8)
Background
Aspirin is a cornerstone in prevention of cardiovascular events and modulates both platelet aggregation and fibrin clot formation. Some patients experience cardiovascular events whilst on aspirin, often termed aspirin treatment failure (ATF). This study evaluated both platelet aggregation and fibrin clot structure in patients with ATF.Methods
We included 177 stable coronary artery disease patients on aspirin monotherapy. Among these, 116 (66%) had ATF defined as myocardial infarction (MI) whilst on aspirin. Platelet aggregation was assessed by Multiplate® aggregometry and VerifyNow®, whereas turbidimetric assays and scanning electron microscopy were employed to study fibrin clot characteristics.Results
Enhanced platelet aggregation was observed in patients with ATF compared with non-MI patients following stimulation with arachidonic acid 1.0 mM (median 161 (IQR 95; 222) vs. 97 (60; 1776) AU*min, p = 0.005) and collagen 1.0 µg/mL (293 (198; 427) vs. 220 (165; 370) AU*min, p = 0.03). Similarly, clot maximum absorbance, a measure of fibrin network density, was increased in patients with ATF (0.48 (0.41; 0.52) vs. 0.42 (0.38; 0.50), p = 0.02), and this was associated with thinner fibres (mean ± SD: 119.7±27.5 vs. 127.8±31.1 nm, p = 0.003) and prolonged lysis time (552 (498; 756) vs. 519 (468; 633) seconds; p = 0.02). Patients with ATF also had increased levels of C-reactive protein (CRP) (1.34 (0.48; 2.94) and 0.88 (0.32; 1.77) mg/L, p = 0.01) compared with the non-MI group. Clot maximum absorbance correlated with platelet aggregation (r = 0.31–0.35, p-values<0.001) and CRP levels (r = 0.60, p<0.001).Conclusions
Patients with aspirin treatment failure showed increased platelet aggregation and altered clot structure with impaired fibrinolysis compared with stable CAD patients without previous MI. These findings suggest that an increased risk of aspirin treatment failure may be identified by measuring both platelet function and fibrin clot structure. 相似文献85.
86.
Josquin Nys Cristian R. Smulski Aubry Tardivel Laure Willen Christine Kowalczyk Olivier Donzé Bertrand Huard Henry Hess Pascal Schneider 《PloS one》2013,8(4)
Myeloid cells express the TNF family ligands BAFF/BLyS and APRIL, which exert their effects on B cells at different stages of differentiation via the receptors BAFFR, TACI (Transmembrane Activator and CAML-Interactor) and/or BCMA (B Cell Maturation Antigen). BAFF and APRIL are proteins expressed at the cell membrane, with both extracellular and intracellular domains. Therefore, receptor/ligand engagement may also result in signals in ligand-expressing cells via so-called “reverse signalling”. In order to understand how TACI-Fc (atacicept) technically may mediate immune stimulation instead of suppression, we investigated its potential to activate reverse signalling through BAFF and APRIL. BAFFR-Fc and TACI-Fc, but not Fn14-Fc, reproducibly stimulated the ERK and other signalling pathways in bone marrow-derived mouse macrophages. However, these effects were independent of BAFF or APRIL since the same activation profile was observed with BAFF- or APRIL-deficient cells. Instead, cell activation correlated with the presence of high molecular mass forms of BAFFR-Fc and TACI-Fc and was strongly impaired in macrophages deficient for Fc receptor gamma chain. Moreover, a TACI-Fc defective for Fc receptor binding elicited no detectable signal. Although these results do not formally rule out the existence of BAFF or APRIL reverse signalling (via pathways not tested in this study), they provide no evidence in support of reverse signalling and point to the importance of using appropriate specificity controls when working with Fc receptor-expressing myeloid cells. 相似文献
87.
88.
Margret Rave-Fränk Ihtzaz Ahmed Malik Hans Christiansen Naila Naz Sadaf Sultan Ahmad Amanzada Martina Blaschke Silke Cameron Shakil Ahmad Clemens Friedrich Hess Giuliano Ramadori Federico Moriconi 《Radiation and environmental biophysics》2013,52(3):321-338
The liver is considered a radiosensitive organ. However, in rats, high single-dose irradiation (HDI) showed only mild effects. Consequences of fractionated irradiation (FI) in such an animal model have not been studied so far. Rats were exposed to selective liver FI (total dose 60 Gy, 2 Gy/day) or HDI (25 Gy) and were killed three months after the end of irradiation. To study acute effects, HDI-treated rats were additionally killed at several time points between 1 and 48 h. Three months after irradiation, no differences between FI and HDI treatment were found for macroscopically detectable small “scars” on the liver surface and for an increased number of neutrophil granulocytes distributed in the portal fields and through the liver parenchyma. As well, no changes in HE-stained tissues or clear signs of fibrosis were found around the portal vessels. Differences were seen for the number of bile ducts being increased in FI- but not in HDI-treated livers. Serum levels indicative of liver damage were determined for alkaline phosphatase (AP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (γGT) and lactate dehydrogenase (LDH). A significant increase of AP was detected only after FI while HDI led to the significant increases of AST and LDH serum levels. By performing RT-PCR, we detected up-regulation of matrix metalloproteinases, MMP-2, MMP-9, MMP-14, and of their inhibitors, TIMP-1, TIMP-2 and TIMP-3, shortly after HDI, but not at 3 month after FI or HDI. Overall, we saw punctual differences after FI and HDI, and a diffuse formation of small scars at the liver surface. Lack of “provisional clot”-formation and absence of recruitment of mononuclear phagocytes could be one explanation for scar formation as incomplete repair response to irradiation. 相似文献
89.
Joelle M. Brown Eugenie Poirot Kristen L. Hess Stephen Brown Michele Vertucci Marjan Hezareh 《PloS one》2016,11(3)
Objective
Intravaginal practices—including behaviors such as intravaginal cleansing and insertion of products—have been linked to a number of adverse reproductive health outcomes, including increased risk for bacterial vaginosis, sexually transmitted infections, and HIV. Currently, little is known about the motivations for intravaginal practices among women in the United States. The objective of this study was to identify and describe motivations for intravaginal washing and intravaginal insertion of products among women of differing ages and racial/ethnic groups.Methods
Between 2008 and 2010, we enrolled a convenience sample of sexually active women aged 18–65 years living in Los Angeles recruited through community education and outreach activities in HIV/AIDS service organizations, women’s health clinics, community-based organizations, and HIV testing sites. At the enrollment visit, women completed a self-administered, computer-assisted questionnaire covering demographics, sexual behaviors, intravaginal practices, and motivations for intravaginal practices over the past month and past year.Results
We enrolled 141 women; 34% of participants were Caucasian, 40% African American, and 26% Latina. Peri-sexual intravaginal washing was common in all groups, whether to clean up after sex (70%) or to prepare for sex (54%). African American women were more likely to report learning to wash intravaginally from their mothers compared to Latina or Caucasian women (70% vs. 49%, P = 0.04). Sixty-one percent of African American women reported using a douching device over the past year compared to 41% of Latina and 40% of Caucasian women (p = 0.02). Younger women were more likely to report that their male partners wanted them to wash intravaginally than older women (77% vs. 24%, P<0.01), and more likely to report the removal of odors as a motive than older women (65% vs. 40%, P = 0.04). The most commonly used intravaginal products included sexual lubricants, petroleum jelly, body lotions, oils, and wet wipes. Use of these products varied by race, and motives given included increasing lubrication, preparing for sex, smelling good, and preventing sexually transmitted infections.Conclusion
Women’s intravaginal practices and motivations for these practices differ across race and age. Motivations for use also vary by type of intravaginal product used. Given that some intravaginal practices have been shown to be harmful, interventions, programs and counseling messages to encourage less harmful practices are needed, and should consider underlying motivations that influence women’s vaginal practices. Practitioners may use these results to better support women in achieving vaginal health. 相似文献90.
Clemens Benjamin J. Weitkamp Laurie Siwicke Kevin Wade Joy Harris Julianne Hess Jon Porter Laurie Parker Keith Sutton Trent Orlov Alexei M. 《Reviews in Fish Biology and Fisheries》2019,29(4):767-788
Reviews in Fish Biology and Fisheries - Pacific lamprey Entosphenus tridentatus has an anadromous life cycle that begins with larvae that filter-feed in freshwater, followed by transformation into... 相似文献