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91.
H. Aoshima D.J. Cash G.P. Hess 《Biochemical and biophysical research communications》1980,92(3):896-904
The dependence of acetylcholine receptor-controlled transmembrane ion flux on carbamylcholine concentration was measured in the msec time region, using membrane vesicles and a quench flow technique. 4 Measurements were made: (1) transmembrane ion influx, (2) rate of inactivation of the receptor by carbamylcholine, (3) rate of recovery, and (4) ion influx mediated by “inactivated” receptor. The minimal model, based on the measurements, accounts for the time dependence of receptor-controlled ion flux over a 200-fold carbamylcholine concentration range. The maximum flux rate of 84 sec?1 indicates that we have succeeded in measuring the receptor-controlled processes which give rise to electrical signals in cells. 相似文献
92.
93.
H. M. C. Kemps R. W. M. Brouwers M. J. Cramer H. T. Jorstad E. P. de Kluiver R. A. Kraaijenhagen P. M. J. C. Kuijpers M. R. van der Linde E. de Melker S. F. Rodrigo R. F. Spee M. Sunamura T. Vromen M. E. Wittekoek 《Netherlands heart journal》2020,28(7):387-390
The ongoing coronavirus disease 2019 (COVID-19) crisis is having a large impact on acute and chronic cardiac care. Due to public health measures and t 相似文献
94.
95.
D. Loakes F. Hill S. Linde D. M. Brown 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):1001-1003
Abstract Nitroindoles behave as non-discriminatory bases when incorporated into oligodeoxynucleotides, without causing significant destabilisation of the duplex, and exhibit higher melting temperatures than 3-nitropyrrole. When 5-nitroindole and 3-nitropyrrole are incorporated into oligomers for use as primers for sequencing and the polymerase chain reaction, both give products but are not as effective as hypoxanthine. 相似文献
96.
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
97.
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
98.
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99.
Rational use of Jatropha curcas L. in food and medicine: from toxicity problems to safe applications
Muhamad Insanu Chryssa Dimaki Richard Wilkins John Brooker Piet van der Linde Oliver Kayser 《Phytochemistry Reviews》2013,12(1):107-119
Jatropha curcas L. has become an important plant for biorefinery and production of biodiesel. From its ethnobotanical use, the plant is known for several activities which are associated with high toxicity. The latest development in engineering technology enables detoxification of native oil and other parts of the plant for new pharmaceutical purposes. Hence a revised look to the rich metabolic spectra of partly structurally rare secondary compound becomes an interesting field of research to be explored. In this review, we discuss recent developments in the technology of detoxification process and give insight about how this ethnomedicinal plant can be applied to new fields of experimental medicine. The review highlights recent data on biological activities and discusses concepts and strategies for turning a poison plant into a valuable crop with high pharmaceutical potential. 相似文献
100.