25 research outputs found

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Triptolide Induces S Phase Arrest and Apoptosis in Gallbladder Cancer Cells

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    Gallbladder carcinoma is the most common malignancy of the biliary tract, with a very low 5-year survival rate and extremely poor prognosis. Thus, new effective treatments and drugs are urgently needed for the treatment of this malignancy. In this study, for the first time we investigated the effects of triptolide on gallbladder cancer cells and identified the mechanisms underlying its potential anticancer effects. The MTT assay showed that triptolide decreased cell viability in a dose- and time-dependent manner. The results of the colony formation assay indicated that triptolide strongly suppressed colony formation ability in GBC-SD and SGC-996 cells. Flow cytometric analysis revealed that triptolide induced S phase arrest in gallbladder cancer cells. In addition, triptolide induced apoptosis, as shown by the results of annexin V/propidium iodide double-staining and Hoechst 33342 staining. Furthermore, triptolide decreased mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Finally, western blot analysis of triptolide-treated cells revealed the activation of caspase-3, caspase-9, PARP, and Bcl-2; this result demonstrated that triptolide induced apoptosis in gallbladder cancer cells by regulating apoptosis-related protein expression, and suggests that triptolide may be a promising drug to treat gallbladder carcinoma

    Schisandrin B Induces Apoptosis and Cell Cycle Arrest of Gallbladder Cancer Cells

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    Gallbladder cancer, with high aggressivity and extremely poor prognosis, is the most common malignancy of the bile duct. The main objective of the paper was to investigate the effects of schisandrin B (Sch B) on gallbladder cancer cells and identify the mechanisms underlying its potential anticancer effects. We showed that Sch B inhibited the viability and proliferation of human gallbladder cancer cells in a dose-, time -dependent manner through MTT and colony formation assays, and decrease mitochondrial membrane potential (ΔΨm) at a dose-dependent manner through flow cytometry. Flow cytometry assays also revealed G0/G1 phase arrest and apoptosis in GBC-SD and NOZ cells. Western blot analysis of Sch B-treated cells revealed the upregulation of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP and downregulation of Bcl-2, NF-κB, cyclin D1 and CDK-4. Moreover, this drug also inhibited the tumor growth in nude mice carrying subcutaneous NOZ tumor xenografts. These data demonstrated that Sch B induced apoptosis in gallbladder cancer cells by regulating apoptosis-related protein expression, and suggests that Sch B may be a promising drug for the treatment of gallbladder cancer

    Improved long‐term outcomes after innovative preoperative evaluation and conception of precise surgery for gallbladder cancer

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    Abstract Background Three‐dimensional visualization preoperative evaluation (3D‐VPE) and enhanced recovery after surgery (ERAS) have been suggested to improve outcomes of cancer surgery in patients, yet little is known regarding their clinical benefit in patients with gallbladder cancer (GBC). We hypothesized that the combination of 3D‐VPE and ERAS would improve the outcome of patients undergoing surgery for GBC. Objective This study aimed to determine if 3D‐VPE and ERAS can improve the outcomes and overall survival in patients with GBC, establishing a novel patient management strategy for GBC. Methods A total of 227 patients with GBC were recruited and divided into two groups: those who received traditional treatment between January 2000 and December 2010 (n = 86; the control group) and those who underwent 3D‐VPE and ERAS between January 2011 and December 2017 (n = 141). Univariate and multivariate analyses were employed to assess the relationship among disease stages, lymph node invasion, and cell differentiation between the two groups. Cox regression analysis was used to investigate patient survival in these groups. Results Patients who underwent 3D‐VPE and ERAS showed a significantly higher R0 resection rate (67.4% vs. 20.9%, p < 0.001) and dissected lymph node number (26.6 ± 12.6 vs. 16.3 ± 7.6 p < 0.001) compared to the control group. The median survival was 27.4 months, and the 1‐ and 3‐year survival rates were 84.4% and 29.8%, respectively, in patients who received combined management; in the control cohort, the median survival was 12.7 months, and the 1‐ and 3‐year survival rates were 53.5% and 15.1%, respectively. In addition, some postoperative complications and risk factors were diminished relative to the traditionally treated patients. Conclusion The implementation of 3D‐VPE and ERAS can significantly improve the prognosis and outcomes of patients with GBC and should be considered for wide use in clinical practice
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