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Oxidative stress affects cellular membrane lipids and proteins. Using whole-cell patch-clamp recording we demonstrate differential oxidative inhibition of voltage-gated transient (IA) and delayed rectifier [IK(V)] K+ currents by arachidonic acid (AA) and H2O2 in CA1 neurons in hippocampal slice. We show that intracellular application of 1 pm AA or its non-metabolizable analog eicosatetraynoic acid (100 pm) reduced IA by approximately 42% but did not affect IK(V). AA shifted the voltage dependence of steady-state inactivation of IA by 12 mV to more negative potentials whereas the rate of inactivation was unchanged. Surprisingly, intracellular glutathione (GSH, 20 mm) enhanced the effect of AA on maximal IA (-62%) and with AA slowed inactivation of IA. The combination of GSH and extracellular ascorbate (0.4 mm) prevented reduction of IA by AA. Intracellular Trolox (a vitamin E analog, 10 microm) reduced IA by 61%and IK(V) by 39%. Like AA, intracellular Trolox caused a 10-mV left shift of IA steady-state inactivation but Trolox and AA did not cause a shift when coapplied. Extracellular Trolox (100 microm) had no effects on IA. H2O2 (80 microm) reduced both IA and IK(V) in a GSH- and ascorbate-sensitive manner and slowed the rate of inactivation of IA by a factor of 2. Coapplication of H2O2 with GSH and extracellular ascorbate caused approximately 22 mV negative shifts of both steady-state inactivation and activation. We conclude that AA is extremely potent in affecting IA by oxidative modifications. Antioxidants can augment these effects, probably by catalysis of the underlying reactions between oxidants and IA channel proteins. 相似文献
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Dominik Herrmann Melanie Oggiano Plamena Gencheva-Bozhkova Monique Braun Gerd Neuhaus Santiago Ewig Erich Hecker 《Interactive Cardiovascular and Thoracic Surgery》2021,32(6):921
Open in a separate windowOBJECTIVESBronchopleural fistula after pneumonectomy and dehiscence of an anastomosis after sleeve lobectomy are severe complications. Several established therapeutic options are available. Conservative treatment is recommended for a small fistula without pleural infection. In patients with a bronchopleural fistula and subsequent pleural empyema, surgical management is the mainstay. Overall, the associated morbidity and mortality are high. Carinal sleeve resection is the last resort for patients with a short stump after pneumonectomy or anastomotic dehiscence after sleeve resection near the carina.METHODSAll patients with bronchopleural fistula after pneumonectomy or sleeve resection who underwent secondary carinal sleeve resection between 2003 and 2019 in our institution were evaluated retrospectively. Patients with anastomotic dehiscence after sleeve lobectomy underwent a completion pneumonectomy. The surgical approach was an anterolateral thoracotomy; the anastomosis was covered with muscle flap, pericardial fat or omentum majus. In case of empyema, povidone-iodine-soaked towels were introduced into the cavity and changed at least twice.RESULTSA total of 17 patients with an initial sleeve lobectomy in 12 patients and pneumonectomy in 5 patients were treated with carinal sleeve resection in our department. Morbidity was 64.7% and 30-day survival was 82.4% (n = 14). A total of 70.6% of the patients survived 90 days (n = 12). Median hospitalization was 17 days and the median stay in the intensive care unit was 12 days.CONCLUSIONSCarinal sleeve resection is a feasible option in patients with a post-pneumonectomy fistula or anastomotic insufficiency following sleeve lobectomy in the absence of alternative therapeutic strategies. Nevertheless, postoperative morbidity is high, including prolonged intensive care unit stay. 相似文献
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Elizabeth M. Vera Plamena Daskalova Lincoln Hill Marissa Floro Bernasha Anderson Meghan Roche Fatma Aydin Kristen Adams Dan Camacho Abdul Raziuddin Andrea Carr 《School mental health》2017,9(4):347-359
While evidence of the mental health effects of bullying has amassed in recent years, less scholarship explores the dynamics of bullying as it manifests in culturally diverse environments. The purpose of this study was to determine how contextual factors influence participation in bullying behaviors in a sample of urban, low-income, ethnic minority students. Using structural equation modeling, researchers tested whether social competence mediates the relationship between (a) parents’ messages about aggression, (b) school belonging, (c) personal control and the outcome of bullying. Results of the study support evidence for a direct relationship between parental messages and bullying, social skills and bullying, parental messages and social skills, and personal control and social skills. Findings also indicate an indirect relationship between personal control and bully perpetration. Implications and directions for future research on contextual factors associated with bullying are discussed. 相似文献
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Georgi Vasilev Plamena Kabakchieva Dimitrina Miteva Hristiana Batselova Tsvetelina Velikova 《World journal of diabetes》2022,13(9):738-751
Diabetes mellitus is one of the most common comorbid conditions encountered in patients with severe acute respiratory syndrome coronavirus 2 infection accompanied by significantly increased mortality, prolonged hospital stay, and requirement of invasive mechanical ventilation. This review aims to present the effectiveness and safety profile of available coronavirus disease 2019 (COVID-19) vaccines in people with diabetes as a potential cause of hesitancy for vaccination. Data from published research proves a robust immune response following immunization for COVID-19 in diabetic patients with substantial production of virus-neutralizing antibodies; however, the observed immune response was unequivocally weaker than that in individuals without diabetes. This observation was further enhanced by the findings that worse glycemic control was associated with more suppressed antibody production. In contrast, individuals with optimal glycemic control performed similarly to healthy controls. In addition to the need for strict glucose monitoring and adequate diabetes treatment, those findings reinforce the concept of diabetes-induced secondary immune deficiency and necessitate the application of booster doses to diabetic patients with priority. Nevertheless, after vaccination, reported adverse events were not different from those in the general population. No increase in severe adverse events was documented. While single case reports detected transient increases in blood glucose post-vaccination, more extensive trials could not replicate such a relationship. 相似文献
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Sebastian Deschler Juliane Kager Johanna Erber Lisa Fricke Plamena Koyumdzhieva Alexandra Georgieva Tobias Lahmer Johannes R. Wiessner Florian Voit Jochen Schneider Julia Horstmann Roman Iakoubov Matthias Treiber Christof Winter Jürgen Ruland Dirk H. Busch Percy A. Knolle Ulrike Protzer Christoph D. Spinner Roland M. Schmid Michael Quante Katrin Bttcher 《Viruses》2021,13(2)
Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), comprises mild courses of disease as well as progression to severe disease, characterised by lung and other organ failure. The immune system is considered to play a crucial role for the pathogenesis of COVID-19, although especially the contribution of innate-like T cells remains poorly understood. Here, we analysed the phenotype and function of mucosal-associated invariant T (MAIT) cells, innate-like T cells with potent antimicrobial effector function, in patients with mild and severe COVID-19 by multicolour flow cytometry. Our data indicate that MAIT cells are highly activated in patients with COVID-19, irrespective of the course of disease, and express high levels of proinflammatory cytokines such as IL-17A and TNFα ex vivo. Of note, expression of the activation marker HLA-DR positively correlated with SAPS II score, a measure of disease severity. Upon MAIT cell-specific in vitro stimulation, MAIT cells however failed to upregulate expression of the cytokines IL-17A and TNFα, as well as cytolytic proteins, that is, granzyme B and perforin. Thus, our data point towards an altered cytokine expression profile alongside an impaired antibacterial and antiviral function of MAIT cells in COVID-19 and thereby contribute to the understanding of COVID-19 immunopathogenesis. 相似文献
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David Schult Sandra Reitmeier Plamena Koyumdzhieva Tobias Lahmer Moritz Middelhof Johanna Erber Jochen Schneider Juliane Kager Marina Frolova Julia Horstmann Lisa Fricke Katja Steiger Moritz Jesinghaus Klaus-Peter Janssen Ulrike Protzer Klaus Neuhaus Roland M. Schmid Dirk Haller Michael Quante 《Gut microbes》2022,14(1)
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Arachidonic acid (AA) is a free fatty acid membrane‐permeable second messenger that is liberated from cell membranes via receptor‐ and Ca2+‐dependent events. We have shown previously that extremely low [AA]i (1 pm ) inhibits the postsynaptic voltage‐gated K+ current (IA) in hippocampal neurons. This inhibition is blocked by some antioxidants. The somatodendritic IA is mediated by Kv4.2 gene products, whereas presynaptic IA is mediated by Kv1.4 channel subunits. To address the interaction of AA with these α‐subunits we studied the modulation of A‐currents in human embryonic kidney 293 cells transfected with either Kv1.4 or Kv4.2 rat cDNA, using whole‐cell voltage‐clamp recording. For both currents 1 pm [AA]i inhibited the conductance by > 50%. In addition, AA shifted the voltage dependence of inactivation by ?9 (Kv1.4) and +6 mV (Kv4.2), respectively. Intracellular co‐application of Trolox C (10 μm ), an antioxidant vitamin E derivative, only slowed the effects of AA on amplitude. Notably, Trolox C shifted the voltage dependence of activation of Kv1.4‐mediated IA by ?32 mV. Extracellular Trolox for > 15 min inhibited the AA effects on IA amplitudes as well as the effect of intracellular Trolox on the voltage dependence of activation of Kv1.4‐mediated IA. Extracellular Trolox further shifted the voltage dependence of activation for Kv4.2 by +33 mV. In conclusion, the inhibition of maximal amplitude of Kv4.2 channels by AA can explain the inhibition of somatodendritic IA in hippocampal neurons, whereas the negative shift in the voltage dependence of inactivation apparently depends on other neuronal channel subunits. Both AA and Trolox potently modulate Kv1.4 and Kv4.2 channel α‐subunits, thereby presumably tuning presynaptic transmitter release and postsynaptic somatodendritic excitability in synaptic transmission and plasticity. 相似文献
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Serban Radian Yoan Diekmann Plamena Gabrovska Brendan Holland Lisa Bradley Helen Wallace Karen Stals Anna‐Marie Bussell Karen McGurren Martin Cuesta Anthony W. Ryan Maria Herincs Laura C. Hernández‐Ramírez Aidan Holland Jade Samuels Elena Daniela Aflorei Sayka Barry Judit Dénes Ida Pernicova Craig E. Stiles Giampaolo Trivellin Ronan McCloskey Michal Ajzensztejn Noina Abid Scott A. Akker Moises Mercado Mark Cohen Rajesh V. Thakker Stephanie Baldeweg Ariel Barkan Madalina Musat Miles Levy Stephen M. Orme Martina Unterländer Joachim Burger Ajith V. Kumar Sian Ellard Joseph McPartlin Ross McManus Gerard J. Linden Brew Atkinson David J. Balding Amar Agha Chris J. Thompson Steven J. Hunter Mark G. Thomas Patrick J. Morrison Márta Korbonits 《Human mutation》2017,38(1):78-85
The aryl hydrocarbon receptor interacting protein (AIP) founder mutation R304* (or p.R304*; NM_003977.3:c.910C>T, p.Arg304Ter) identified in Northern Ireland (NI) predisposes to acromegaly/gigantism; its population health impact remains unexplored. We measured R304* carrier frequency in 936 Mid Ulster, 1,000 Greater Belfast (both in NI) and 2,094 Republic of Ireland (ROI) volunteers and in 116 NI or ROI acromegaly/gigantism patients. Carrier frequencies were 0.0064 in Mid Ulster (95%CI = 0.0027–0.013; P = 0.0005 vs. ROI), 0.001 in Greater Belfast (0.00011–0.0047) and zero in ROI (0–0.0014). R304* prevalence was elevated in acromegaly/gigantism patients in NI (11/87, 12.6%, P < 0.05), but not in ROI (2/29, 6.8%) versus non‐Irish patients (0–2.41%). Haploblock conservation supported a common ancestor for all the 18 identified Irish pedigrees (81 carriers, 30 affected). Time to most recent common ancestor (tMRCA) was 2550 (1,275–5,000) years. tMRCA‐based simulations predicted 432 (90–5,175) current carriers, including 86 affected (18–1,035) for 20% penetrance. In conclusion, R304* is frequent in Mid Ulster, resulting in numerous acromegaly/gigantism cases. tMRCA is consistent with historical/folklore accounts of Irish giants. Forward simulations predict many undetected carriers; geographically targeted population screening improves asymptomatic carrier identification, complementing clinical testing of patients/relatives. We generated disease awareness locally, necessary for early diagnosis and improved outcomes of AIP‐related disease. 相似文献