Enhancement of gefitinib-induced growth inhibition by Marsdenia tenacissima extract in non-small cell lung cancer cells expressing wild or mutant EGFR.

BACKGROUND: Non-small cell lung cancer (NSCLC) expressed high levels of epidermal growth factor receptor (EGFR). Gefitinib (Iressa) has demonstrated clinical efficacy in NSCLC patients harboring EGFR mutations or refractory to chemotherapy. However, most of NSCLC patients are with wild type EGFR, and showed limited response to gefitinib. Therefore, to develop new effective therapeutic interventions for NSCLC is still required. Our previous study showed Marsdenia tenacissima extract (MTE) restored gefitinib efficacy in the resistant NSCLC cells, but whether MTE acts in the gefitinib-sensitive NSCLC cells is the same as it in the resistant one is unknown. METHODS: Dose response curves for gefitinib and MTE were generated for two sensitive NSCLC cell lines with mutant or wild type EGFR status. Three different sequential combinations of MTE and gefitinib on cell growth were evaluated using IC50 and Combination Index approaches. The flow cytometric method was used to detect cell apoptosis and cell cycle profile. The impact of MTE combined with gefitinib on cell molecular network response was studied by Western blotting. RESULTS: Unlike in the resistant NSCLC cells, our results revealed that low cytotoxic dose of MTE (8 mg/ml) combined gefitinib with three different schedules synergistically or additively enhanced the growth inhibition of gefitinib. Among which, MTE→MTE+gefitinib treatment was the most effective one. MTE markedly prompted cell cycle arrest and apoptosis caused by gefitinib both in EGFR mutant (HCC827) and wild type of NSCLC cells (H292). The Western blotting results showed that MTE→MTE+gefitinib treatment further enhanced the suppression of gefitinib on cell growth and apoptosis pathway such as ERK1/2 and PI3K/Akt/mTOR. This combination also blocked the activation of EGFR and c-Met which have cross-talk with each other. Unlike in gefitinib-resistant NSCLC cells, MTE alone also demonstrated certain unexpected modulation on EGFR related cell signal pathways in the sensitive cells. CONCLUSION: Our results suggest that MTE is a promising herbal medicine to improve gefitinib efficacy in NSCLC regardless of EGFR status. However, why MTE acted differently between gefitinib-sensitive and -resistant NSCLC cells needs a further research.

Assessing patient safety culture in obstetrics ward: A pilot study using a modified Manchester Patient Safety Framework in China.

AIM: The primary objective of this study was to assess the patient safety culture in a general hospital in Shanghai, China, through a modified Manchester Patient Safety Framework (MaPSaF). DESIGN: This study has a qualitative interview design. Data were collected through group interviews and analyses performed through content analysis. METHODS: The MaPSaF was translated into Chinese and used to assess the patient safety culture in a large general hospital in Shanghai, China. Group interviews using the MaPSaF were conducted with 15 nurses in the obstetric ward. Participants rated their safety practice individually on each of the nine MaPSaF safety culture dimensions. The dimensions and scores were then collectively discussed and a practice-wide consensus score for each dimension was agreed. Discussions were recorded, transcribed and analysed to assess patient safety in the obstetric ward. RESULTS: It took about 2 hr to complete the discussion focusing on patients' safety employing the MaPSaF. Most participants recognized the process as acceptable and useful. The MaPSaF directed team discussion about patient safety issues and facilitated communication, prompting some practice changes. All participants responded positively to the discussion and perceived MaPSaF as a good safety culture assessment tool, with clear, comprehensive and understandable entries. The process demonstrated that the department of obstetrics in the hospital already had a positive patient safety culture, but certain areas were highlighted as still needing improvement. Based on participants' positive experience and perception of the MaPSaF, it can be concluded that there is potential benefit in its adaptation and use in obstetrics wards of Chinese hospitals. The MaPSaF has the potential to strengthen existing safety cultures and improve general safety through collaborative measures.

Left atrial appendage closure in patients with reversed chicken-wing morphology: Anatomical features and procedural strategy.

Background: Left atrial appendage (LAA) closure (LAAC) in atrial fibrillation (AF) patients with the reversed chicken-wing (RCW) LAA is challenging. Aims: To elucidate the LAAC strategy of the RCW-LAA. Methods: A total of 802 AF patients who were enrolled in the LAACablation registry for LAAC procedure were included, 55 of whom presented with the RCW-LAA. The WATCHMAN device was implanted using the standard protocol when the sheath depth was no less than the device depth (the simple group). For those with a sheath depth of less than the device depth (the complex group), device deployment was attempted with acceptable protrusion or after a repeated atrial transseptal puncture (re-ATP) at a more inferior and anterior position. The anatomical and procedural features were compared between groups and before and after the re-ATP. Results: The success rate of LAAC was significantly lower in patients with the RCW-LAA than with the other morphologies (92.7% vs. 98.8%, p = 0.001). Compared with the simple group, the complex group had shorter root depth and shorter neck length, and more LAAs in the complex group were at lower position (all p < 0.05). The sheath depth after the re-ATP was significantly greater than that before the re-ATP (18.8 ± 3.4 mm vs. 14.7 ± 2.6 mm, p < 0.001). For the patients who underwent re-ATP, the sheath went significantly deeper in successful procedures than in aborted procedures (19.7 ± 3.3 mm vs. 15.8 ± 1.8 mm, p = 0.040). Conclusions: The anatomical features of the RCW-LAA were related to the complexity of the LAAC procedure. The re-ATP at an inferior and anterior location could increase the success rate of LAAC. ClinicalTrialsgov: NCT03788941.

[A methodology study on flow cytometric analysis of cell DNA stained with DAPI and Hoechst33342].

OBJECTIVE: To discuss a simple method for flow cytometric analysis of cell DNA stained with DAPI and Hoechst33342. METHODS: HT 29 cells stained with DAPI, Hoechst33342 or PI were measured by BD FACSAria and the percentages of cells in G0/G1, S and G2/M phases with three staining methods, then the results were analyzed and compared. Before measurement we monitored the quality of DNA analysis of flow cytometer through UV beads QC experiment and analyzed the standard chicken erythrocyte nuclei (CEN) and calf thymocyte nuclei (CTN) stained with DAPI and Hoechst33342. RESULTS: CV value of UV peak was 2.4 after QC experiments. There were 4 peaks on CEN histograms and the ratios of peak channel mean of G2/G1, G3/G1, and G4/G1 were about 2, 3, and 4 respectively. Both CV values of the first peak were 2.4. There were 2 peaks on CTN histograms and the ratio of peak channel mean of G2/G1 was 1.97, and CV value of G0/G1 2.4. The complete cell cycle of HT29 cells stained with DAPI, Hoechst33342 or PI was showed entirely, CV values were 3.40, 3.02 and 4.42, respectively, and the percentages of cells in G0/G1 were 60.86%, 60.22% and 60.81%,respectively, in S, 28.85%, 29.70% and 29.82%,respectively, and in G2/M, 10.29%, 9.09% and 9.37%, respectively. The results by the three methods showed no difference. CONCLUSION: This method for measurement of cellular DNA content is a simple and efficient approach to determining cell cycle and can be the first choice when using flow cytometer with 355 nm UV.