23 research outputs found
The accuracy of the aerosol particle mass analyzer for nanoparticle classification
<p>The aerosol mass measurement method, DMA-APM, measures a lower mass as compared to the electrical mobility diameter-based particle mass for sub-50 nm nanoparticles. The extent of underestimation increases with decreasing nanoparticle diameter and can reach as much as 20–80% for different nanoparticles between 10–20 nm. To study this issue, the DMA-APM system was tested with traceable size standards (PSL and NanoSilica) and laboratory generated silver nanoparticles. It was found that the extent of mass underestimation depended on Brownian diffusion as well as the strength of the classifying forces, and the extent was quantified by a dimensionless parameter , which is suggested to be higher than 40 to eliminate the mass underestimation for size standards. Further analysis also showed that the uncertainty in the particle density of test nanoparticles should be as low as possible to minimize the error in the judgment on the accuracy of the APM. Finally, the absolute accuracy of the APM at different was determined by the size standards, which could be used to correct for the mass underestimation for sub-50 nm nanoparticles.</p> <p>Copyright © 2018 American Association for Aerosol Research</p
5-Azacytidine Induces Anoikis, Inhibits Mammosphere Formation and Reduces Metalloproteinase 9 Activity in MCF-7 Human Breast Cancer Cells
Cancer stem cells are a subset of cancer cells that initiate the growth of tumors. Low levels of cancer stem cells also exist in established cancer cell lines, and can be enriched in serum-free tumorsphere cultures. Since cancer stem cells have been reported to be resilient to common chemotherapeutic drugs in comparison to regular cancer cells, screening for compounds selectively targeting cancer stem cells may provide an effective therapeutic strategy. We found that 5-azacytidine (5-AzaC) selectively induced anoikis of MCF-7 in suspension cultures with an EC50 of 8.014 µM, and effectively inhibited tumorsphere formation, as well as the migration and matrix metalloproteinases-9 (MMP-9) activity of MCF-7 cells. Furthermore, 5-AzaC and radiation collaboratively inhibited MCF-7 tumorsphere formation at clinically relevant radiation doses. Investigating the underlying mechanism may provide insight into signaling pathways crucial for cancer stem cell survival and pave the way to novel potential therapeutic targets
Usefulness of Drug Eluting Stent in Percutaneous Coronary Intervention—A Single Center Experience in Taiwan
Drug eluting stents (DES) have been shown to reduce in-stent restenosis rate and target vessel revascularization in large clinical trials. However, the safety and efficacy of DES use in the Taiwanese population has not been reported. We designed this trial to analyze the clinical results in patients using DES in a single tertiary center.
Methods: We retrospectively analyzed the clinical data of all patients treated at National Taiwan University Hospital, Taipei, Taiwan, with sirolimus- or paclitaxel-eluting stents between September 2003 and January 2005.
Results: A total of 585 patients (466 men, 119 women; mean age, 64.5 ± 11.2 years) were enrolled. Meanwhile, 205 sirolimus- and 717 paclitaxel-eluting stents were implanted, with a mean of 1.6 stents per patient. Half (50.2%) of the stents were placed in the left anterior descending artery. Among the enrolled patients, 41.8% had diabetes mellitus, 25% had a diagnosis of acute coronary syndrome, and 10.7% was treated with primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. Overall 8-month target vessel revascularization, major adverse cardiac event rate, and cardiac death rate were 8.8%, 9.7% and 2.5%, respectively. There was no difference in clinical events between sirolimus- and paclitaxel-eluting stents. The overall subacute stent thrombosis rate was 1.36%, significantly lower than that in patients who presented with acute coronary syndrome (4%).
Conclusion: The use of DES in the Taiwanese population yielded comparable results as those in large clinical trials. Subacute stent thrombosis rate was higher in acute coronary syndrome. The safety of DES in these situations should be further clarified
<i>EGFR</i> FISH between cobas+/Sanger+ and cobas+/Sanger− group.
(A) The percentage of EGFR high copy number gain (Colorado score 5) + amplification (Colorado score 6) was significantly higher in the cobas+/Sanger− group compared with the cobas+/Sanger+ group. (B) This case reported to have ex20ins mutations by cobas test but not detected by Sanger sequencing and Idylla assay, with high-grade complex glandular structures and (C) EGFR amplification featured by large clusters of EGFR signals (green). (D) This case reported to have ex20ins mutations by cobas test but not detected by Sanger sequencing and Idylla assay, with high-grade micropapillary patterns and (E) EGFR amplification (more than 15 copies per cell). Hematoxylin and eosin (B, D) and EGFR FISH, green (EGFR) and red (CEN7) signals (C, E).</p
Clinicopathological features between ex20ins cobas+/Sanger+ and cobas+/Sanger-groups.
Clinicopathological features between ex20ins cobas+/Sanger+ and cobas+/Sanger-groups.</p
Comparison of <i>EGFR</i> mutation results using Sanger sequencing and the cobas EGFR assay at NTUH between January 2015 and December 2022.
Comparison of EGFR mutation results using Sanger sequencing and the cobas EGFR assay at NTUH between January 2015 and December 2022.</p