A Genomic Study of DNA Alteration Events Caused by Ionizing Radiation in Human Embryonic Stem Cells via Next-Generation Sequencing

From Patient Material to New Discoveries: a Methodological Review and Guide for Intestinal Stem Cell Researchers

Intestinal stem cells (ISC) are characterized by their ability to continuously self-renew and differentiate into various functionally distinct intestinal epithelial cell types. Impaired stem cell proliferation and differentiation can cause severe dysfunction of the gastrointestinal tract and lead to the development of several clinical disorders. Animal mouse models provide a valuable platform to study ISC function, disease mechanisms, and the intestinal epithelium's regenerative capacity upon tissue damage. However, advanced in vitro systems that are more relevant to human physiology are needed to understand better the diverse disease-triggering factors and the heterogeneity in clinical manifestations. Intestinal biopsies from patients might serve as potent starting material for such "gut-in-a-dish" approaches. While many promising tools for intestinal tissue processing, in vitro expansion, and downstream analysis have been developed in recent years, a comprehensive guide with recommendations to successfully launch or improve intestinal stem cell culture is missing. In this review, we present a selection of currently established methods, highlight recent publications and discuss the potential and limitations of those methodological approaches to facilitate and support the future design of novel and more personalized therapeutic options.

Impact of the weekday of the first intensity-modulated radiotherapy treatment on the survival outcomes of patients with nasopharyngeal carcinoma: A multicenter cohort study

BACKGROUND

This study's purpose was to assess whether the weekday on which intensity-modulated radiotherapy (IMRT) is initiated influences survival outcomes in patients with nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

A total of 1440 patients with NPC who received IMRT were enrolled in this study between January 2010 and June 2016. The patients were divided into five groups according to the weekday of their first radiotherapy treatment. Group 1 (n = 322), Group 2 (n = 322), Group 3 (n = 286), Group 4 (n = 292) and Group 5 (n = 218) received first radiotherapy on Monday, Tuesday, Wednesday, Thursday and Friday respectively. Differences in the rates of overall survival (OS), disease-free survival (DFS), loco-regional relapse-free survival (LRRFS) and distant metastasis-free survival (DMFS) were compared among the five groups using the Kaplan-Meier method and Cox regression models.

RESULTS

No significant differences were found in OS, DFS, LRRFS or DMFS among the five groups. The Cox regression analysis showed that the weekday on which the radiotherapy was initiated was not an independent predictor of OS (Hazard Ratio [HR], 1.056; 95%CI: 0.959-1.164, P = 0.268), DFS (HR, 1.067; 95% CI: 0.980-1.161, P = 0.137), LRRFS (HR, 1.069; 95% CI: 0.914-1.249, P = 0.404) and DMFS (HR, 1.027; 95% CI: 0.929-1.134, P = 0.607). The subgroup analysis showed no significant differences among the five groups.

CONCLUSIONS

This study showed that the day of the week that patients with nasopharyngeal carcinoma begin radiotherapy has no effect on their survival outcomes.