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The protein–nanomaterial interface 总被引:1,自引:1,他引:0
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The effects of histamine on the activity of rapidly adapting receptors (RAR) of the airways were investigated in anesthetized dogs. With bolus injections given into the right atrium, the threshold dose of histamine required for the excitation of RAR (n = 7) was 0.82 microgram/kg (+1.33/-0.51, geometric mean). With increasing doses of histamine, a dose-response relationship was seen in the activity of RAR. Obstruction of the lymphatic drainage from the lungs reduced the threshold dose to histamine (i.e., shifted the dose-response curve to the left significantly). This change in the dose-response relationship was not accompanied by a corresponding change in the relationship of histamine dose to airway pressures recorded before and after lymphatic obstruction. Against a background of pulmonary venous congestion produced by partial obstruction of the mitral valve, subthreshold doses of histamine stimulated the RAR (n = 4). The excitatory effect of histamine on RAR was found to be abolished by the administration of the H1 receptor antagonist diphenhydramine but not by the H2 receptor antagonist cimetidine. Intravenous infusion of histamine (0.4 microgram.kg-1.min-1) for a period of 10 min increased the RAR activity (n = 6) significantly without producing detectable changes in airway mechanics. The results indicate that contraction of the smooth muscle of the airways may not be a prerequisite for the excitation of RAR, especially at low doses. It is suggested that some of the effects of histamine on RAR are mediated by a local expansion of the extravascular fluid caused by an increase in the permeability of the bronchial vasculature. 相似文献
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The effects of cardiogenic and noncardiogenic pulmonary edema on the activities of rapidly adapting receptors (RARs) and pulmonary C-fibre receptors were investigated in dogs anaesthetized with chloralose. Cardiogenic pulmonary edema was produced by elevating the mean left atrial pressure by 25 mmHg (1 mmHg = 133.32 Pa) above the control value for a period of 45 min, by partial obstruction of the mitral valve. Noncardiogenic pulmonary edema was produced by injecting alloxan (100 mg/kg) intravenously. The effect of the latter was examined on RARs alone. Cardiogenic edema activated RARs (n = 8) and the activity was greatest during the first few minutes after elevation of mean left atrial pressure. The pulmonary C-fibre receptors (n = 6) were also activated by cardiogenic edema, but these responses were variable. Noncardiogenic pulmonary edema also activated RAR (n = 6), and this response was maintained during the entire recording period (20 min). The extravascular lung water (%), measured 15 min (n = 5) and 45 min (n = 5) after the elevation of the mean left atrial pressure, was significantly elevated above control values. However, these two values were not significantly different from each other. The extravascular lung water increased significantly after the injection of alloxan also (n = 5). These results show that during pulmonary edema, there is significant stimulation of the RARs and the pulmonary C-fibre receptors. It is suggested that the reflex respiratory responses observed in pulmonary edema may be due to the activation of both the RARs and the pulmonary C-fibre receptors. 相似文献
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Rocío Joo Andrea Snchez-Tapia Sara Mortara Yanina Bellini Saibene Heather Turner Dorothea Hug Peter Natalia Soledad Morandeira Matt Bannert Batool Almazrouq Elizabeth Hare Laura Acin Juan Pablo Narvez-Gmez Marcela Alfaro Crdoba Federico Marini Rita Giordano Silvia Caneln Anicet Ebou Adithi R. Upadhya Joselyn Chvez Janani Ravi 《PLoS computational biology》2022,18(7)
Conferences are spaces to meet and network within and across academic and technical fields, learn about new advances, and share our work. They can help define career paths and create long-lasting collaborations and opportunities. However, these opportunities are not equal for all. This article introduces 10 simple rules to host an inclusive conference based on the authors’ recent experience organizing the 2021 edition of the useR! statistical computing conference, which attracted a broad range of participants from academia, industry, government, and the nonprofit sector. Coming from different backgrounds, career stages, and even continents, we embraced the challenge of organizing a high-quality virtual conference in the context of the Coronavirus Disease 2019 (COVID-19) pandemic and making it a kind, inclusive, and accessible experience for as many people as possible. The rules result from our lessons learned before, during, and after the organization of the conference. They have been written mainly for potential organizers and selection committees of conferences and contain multiple practical tips to help a variety of events become more accessible and inclusive. We see this as a starting point for conversations and efforts towards building more inclusive conferences across the world. * Translated versions of the English abstract and the list of rules are available in 10 languages in S1 Text: Arabic, French, German, Italian, Japanese, Korean, Portuguese, Spanish, Tamil, and Thai. 相似文献
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Parkash R Aggarwal DD Ranga P Singh D 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2012,182(5):625-640
Laboratory selection experiments have evidenced storage of energy metabolites in adult flies of desiccation and starvation resistant strains of D. melanogaster but resource acquisition during larval stages has received lesser attention. For wild populations of D. melanogaster, it is not clear whether larvae acquire similar or different energy metabolites for desiccation and starvation resistance. We tested the hypothesis whether larval acquisition of energy metabolites is consistent with divergence of desiccation and starvation resistance in darker and lighter isofemale lines of D. melanogaster. Our results are interesting in several respects. First, we found contrasting patterns of larval resource acquisition, i.e., accumulation of higher carbohydrates during 3rd instar larval stage of darker flies versus higher levels of triglycerides in 1st and 2nd larval instars of lighter flies. Second, 3rd instar larvae of darker flies showed ~40?h longer duration of development at 21°C; and greater accumulation of carbohydrates (trehalose and glycogen) in fed larvae as compared with larvae non-fed after 150?h of egg laying. Third, darker isofemale lines have shown significant increase in total water content (18%); hemolymph (86%) and dehydration tolerance (11%) as compared to lighter isofemale lines. Loss of hemolymph water under desiccation stress until death was significantly higher in darker as compared to lighter isofemale lines but tissue water loss was similar. Fourth, for larvae of darker flies, about 65% energy content is contributed by carbohydrates for conferring greater desiccation resistance while the larvae of lighter flies acquire 2/3 energy from lipids for sustaining starvation resistance; and such energy differences persist in the newly eclosed flies. Thus, larval stages of wild-caught darker and lighter flies have evolved independent physiological processes for the accumulation of energy metabolites to cope with desiccation or starvation stress. 相似文献