This paper aims to screen and identify sphere clone cells with characteristics similar to cancer stem cells in human gallbladder
cancer cell line GBC-SD. GBC-SD cells were cultured in a serum-free culture medium with different concentrations of the chemotherapeutic
drug cisplatin for generating sphere clones. The mRNA expressions of stem cell-related genes CD133, OCT-4, Nanog, and drug
resistance genes ABCG2 and MDR-1 in sphere clones were detected by quantitative real-time polymerase chain reaction (PCR).
Stem cell markers were also analyzed by flow cytometry and immunofluorescent staining. Different amounts of sphere clones
were injected into nude mice to test their abilities to form tumors. Sphere clones were formed in serum-free culture medium
containing cisplatin (30 μmol/L). Flow cytometry results demonstrated that the sphere clones expressed high levels of stem
cell markers CD133+ (97.6%) and CD44+ (77.9%) and low levels of CD24+ (2.3%). These clones also overexpressed the drug resistance genes ABCG2 and MDR-1. Quantitative real-time PCR showed that
sphere clones expressed stem cell genes Nanog and OCT-4 284 and 266 times, respectively, more than those in the original GBC-SD
cells. Immunofluorescent staining showed that sphere clones overexpressed OCT-4, Nanog, and SOX-2, and low expressed MUC1
and vimentin. Tumor formation experiments showed that 1×103 sphere clone cells could induce much larger tumors in nude mice than 1×105 GBC-SD cells. In conclusion, sphere clones of gallbladder cancer with stem cell-like characteristics can be obtained using
suspension cultures of GBC-SD cells in serum-free culture medium containing cisplatin. 相似文献
Anatomy is an important component in the vertical integration of basic science and clinical practice. Two common pedagogies are cadaveric dissection and examination of prosected specimens. Comparative studies mostly evaluate their immediate effectiveness. A randomized controlled trial design was employed to compare both the immediate and long-term effectiveness of dissection and prosection. Eighty third-year medical students undergoing their surgical rotation from the Yong Loo Lin School of Medicine were randomized into two groups: dissection and prosection. Each participated in a one-day hands-on course following a similar outline that demonstrated surgical anatomy in the context of its clinical relevance. A pre-course test was conducted to establish baseline knowledge. A post-course test was conducted immediately after and at a one-year interval to evaluate learner outcome and knowledge retention. A post-course survey was conducted to assess participant perception. Thirty-nine and thirty-eight participants for the dissection and prosection groups, respectively, were included for analysis. There was no significant difference between mean pre-course test scores between the dissection and prosection groups [12.6 (3.47) vs. 12.7 (3.16), P > 0.05]. Both the mean immediate [27.9 (4.30) vs. 24.9 (4.25), P < 0.05] and 1 year [23.9 (4.15) vs. 19.9 (4.05), P < 0.05] post-course test scores were significantly higher in the dissection group. However, when adjusted for course duration [dissection group took longer than prosection group (mean 411 vs. 265 min)], these findings were negated. There is no conclusive evidence of either pedagogy being superior in teaching surgical anatomy. Based on learner surveys, dissection provides a greater learner experience. 相似文献
Osteoporosis (OP) has become a major public health issue, threatening the bone health of middle-aged and elderly people from all around the world. Changes in the gut microbiota (GM) are correlated with the maintenance of bone mass and bone quality. However, research results in this field remain highly controversial, and no systematic review or meta-analysis of the relationship between GM and OP has been conducted. This paper addresses this shortcoming, focusing on the difference in the GM abundance between OP patients and healthy controls based on previous 16S ribosomal RNA (rRNA) gene sequencing results, in order to provide new clinical reference information for future customized prevention and treatment options of OP.
Methods
According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we comprehensively searched the databases of PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI). In addition, we applied the R programming language version 4.0.3 and Stata 15.1 software for data analysis. We also implemented the Newcastle-Ottawa Scale (NOS), funnel plot analysis, sensitivity analysis, Egger’s test, and Begg’s test to assess the risk of bias.
Results
This research ultimately considered 12 studies, which included the fecal GM data of 2033 people (604 with OP and 1429 healthy controls). In the included research papers, it was observed that the relative abundance of Lactobacillus and Ruminococcus increased in the OP group, while the relative abundance for Bacteroides of Bacteroidetes increased (except for Ireland). Meanwhile, Firmicutes, Blautia, Alistipes, Megamonas, and Anaerostipes showed reduced relative abundance in Chinese studies. In the linear discriminant analysis Effect Size (LEfSe) analysis, certain bacteria showed statistically significant results consistently across different studies.
Conclusions
This observational meta-analysis revealed that changes in the GM were correlated with OP, and variations in some advantageous GM might involve regional differences.
