Study on Influencing Factors of Environmental Testing Quality of Medical Device Manufacturers Clean Workshops / 中国医疗器械杂志

OBJECTIVE@#Improve the quality of testing in medical device manufacturers clean workshops to ensure the authenticity and reliability of testing data.@*METHODS@#Analyze the problems and influencing factors found in the process of testing of medical device manufacturers clean workshops from 2016 to 2020, and put forward reasonable suggestions to ensure the quality of testing.@*RESULTS@#In the process of testing, there are six factors that affect the quality of testing, including testing personnel, instruments and equipment, testing consumables, testing methods, testing environment and actual operation.@*CONCLUSIONS@#To improve the quality of testing, should strengthen the training of testing personnel, continuously improve the testing quality management system, establish an effective information communication mechanism, find out the influencing factors in time, provide objective, real and effective testing data for medical device manufacturing enterprises, and provide technical support for the production and supervision of medical devices.

MicroRNA expression in alpha and beta cells of human pancreatic islets.

microRNAs (miRNAs) play an important role in pancreatic development and adult ß-cell physiology. Our hypothesis is based on the assumption that each islet cell type has a specific pattern of miRNA expression. We sought to determine the profile of miRNA expression in α-and ß-cells, the main components of pancreatic islets, because this analysis may lead to a better understanding of islet gene regulatory pathways. Highly enriched (>98%) subsets of human α-and ß-cells were obtained by flow cytometric sorting after intracellular staining with c-peptide and glucagon antibody. The method of sorting based on intracellular staining is possible because miRNAs are stable after fixation. MiRNA expression levels were determined by quantitative high throughput PCR-based miRNA array platform screening. Most of the miRNAs were preferentially expressed in ß-cells. From the total of 667 miRNAs screened, the Significant Analysis of Microarray identified 141 miRNAs, of which only 7 were expressed more in α-cells (α-miRNAs) and 134 were expressed more in ß-cells (ß-miRNAs). Bioinformatic analysis identified potential targets of ß-miRNAs analyzing the Beta Cell Gene Atlas, described in the T1Dbase, the web platform, supporting the type 1 diabetes (T1D) community. cMaf, a transcription factor regulating glucagon expression expressed selectively in α-cells (TFα) is targeted by ß-miRNAs; miR-200c, miR-125b and miR-182. Min6 cells treated with inhibitors of these miRNAs show an increased expression of cMaf RNA. Conversely, over expression of miR-200c, miR-125b or miR-182 in the mouse alpha cell line αTC6 decreases the level of cMAF mRNA and protein. MiR-200c also inhibits the expression of Zfpm2, a TFα that inhibits the PI3K signaling pathway, at both RNA and protein levels.In conclusion, we identified miRNAs differentially expressed in pancreatic α- and ß-cells and their potential transcription factor targets that could add new insights into different aspects of islet biology and pathophysiology.