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排序方式: 共有1322条查询结果,搜索用时 15 毫秒
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Adna Ai Jasminka Prguda-Muji Lana Salihefendi Larisa Bei Daria Ler Ivana eko Almira Hadovi-Duvo Sead Jai Rijad Konjhodi Damir Marjanovi 《Archives of Medical Science》2021,17(3):823
IntroductionSerological detection of SARS-CoV-2-specific immunoglobulins G (IgG) and M (IgM) antibodies is becoming increasingly important in the management of the COVID-19 pandemic.MethodsWe report the first results of COVID-19 serological testing in Bosnia and Herzegovina on 2841 samples collected and analysed in 2 medical institutions in Sarajevo. Antibody detection was performed using commercially available kits.ResultsIn the first cohort, 43 IgM-positive/IgG-negative and 16 IgM-positive/IgG-positive individuals were detected, corresponding to 3.41% of participants having developed antibodies. In the second cohort, 4.28% participants were found to be IgM-negative/IgG-positive.ConclusionsOur results suggest the need for population-wide serological surveying in Bosnia and Herzegovina. 相似文献
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Vini Gautam Jack Drury Julian M. C. Choy Christian Stricker Hans-A. Bachor Vincent R. Daria 《Biomedical optics express》2015,6(10):4027-4036
We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane’s input resistance.OCIS codes: (170.3880) Medical and biological imaging, (170.3660) Light propagation in tissues, (140.0140) Lasers and laser optics, (170.2520) Fluorescence microscopy, (170.6930) Tissue, (110.0110) Imaging systems 相似文献
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Daria Soroka Inès Li de la Sierra-Gallay Vincent Dubée Sébastien Triboulet Herman van Tilbeurgh Fabrice Compain Lluis Ballell David Barros Jean-Luc Mainardi Jean-Emmanuel Hugonnet Michel Arthur 《Antimicrobial agents and chemotherapy》2015,59(9):5714-5720
Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G132N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 104-fold increase in kcat (0.41 s−1), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G132N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G132N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam–clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies. 相似文献
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Anna Szumera‐Ciekiewicz Grzegorz Rymkiewicz Kamil Sok Ewa Paszkiewicz‐Kozik Anita Borysiuk Jan Poleszczuk Katarzyna Bachnio Zbigniew Bystydzienski Renata Woroniecka Beata Grygalewicz Martyna Kotarska Monika Staczak Daria Owczarek Beata Pytlak Monika Prochorec‐Sobieszek Jan Walewski 《International journal of laboratory hematology》2020,42(4):453-463
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Varun K. Krishnamurthy Ashlie N. Evans Janaka P. Wansapura Hanna Osinska Kelsey E. Maddy Stefanie V. Biechler Daria A. Narmoneva Richard L. Goodwin Robert B. Hinton 《Annals of biomedical engineering》2014,42(10):2014-2028
Aortopathy is characterized by vascular smooth muscle cell (VSMC) abnormalities and elastic fiber fragmentation. Elastin insufficient (Eln +/? ) mice demonstrate latent aortopathy similar to human disease. We hypothesized that aortopathy manifests primarily in the aorto-pulmonary septal (APS) side of the thoracic aorta due to asymmetric cardiac neural crest (CNC) distribution. Anatomic (aortic root vs. ascending aorta) and molecular (APS vs. non-APS) regions of proximal aorta tissue were examined in adult and aged wild type (WT) and mutant (Eln +/? ) mice. CNC, VSMCs, elastic fiber architecture, proteoglycan expression, morphometrics and biomechanical properties were examined using histology, 3D reconstruction, micropipette aspiration and in vivo magnetic resonance imaging (MRI). In the APS side of Eln +/? aorta, Sonic Hedgehog (SHH) is decreased while SM22 is increased. Elastic fiber architecture abnormalities are present in the Eln +/? aortic root and APS ascending aorta, and biglycan is increased in the aortic root while aggrecan is increased in the APS aorta. The Eln +/? ascending aorta is stiffer than the aortic root, the APS side is thicker and stiffer than the non-APS side, and significant differences in the individual aortic root sinuses are observed. Asymmetric structure–function abnormalities implicate regional CNC dysregulation in the development and progression of aortopathy. 相似文献