ABSTRACT
Objective:To study the distribution of CT doses to paediatric patients in Shanghai by investigating the CT dose parameters availiable in Shanghai′s children′s hospticals, and to provide the basis for establishing the diagnostic reference level for the paediatic patients subjected to CT scanning in Shanghai.Methods:In 2021, a general survey was carried out of the CT doses to the head, chest and abdomen of the scanned paediatric patients in four children′s hospitals in the municipality. The scanned paediatic patients were divided into four age groups of 0-, 1-, 5- and 10-15 years old, each with 30 subjects. The basic information were collected on the subjects, CT scanning parameters, volume CT dose index (CTDI vol) and dose length product (DLP). SPSS 16.0 was used to carry out statistical analysis of the differences in CTDI vol and DLP between different age groups at the same site and between different hospitals for the same age group at the same site. Results:The 75 th percentile values of CTDI vol and DLP for 0-, 1-, 5- and 10-15 age groups were 25, 25, 28, 43 mGy and 402, 477, 504, 752 mGy·cm, respectively, for head scanning; 2.7, 2.2, 2.8, 5.4 mGy and 40, 48, 75 and 176 mGy·cm for chest; and 4.9, 4.4, 8.2, 12 mGy and 106, 131, 273, 471 mGy·cm for abdomen. There were significant differences in CTDI vol and DLP between different age groups at the same site and between different hospitals for the same age group at the same site (head, chest and abdomen CTDI vol:χ2=221.68, 167.27, 127.07, DLP: χ2=220.63, 261.46, 216.61; for four age groups, CTDI vol: head χ2=30.46, 38.39, 25.21, 73.04, chest χ2=30.46, 35.69, 58.92, and 48.03, abdomen χ2=66.58, 41.62, 48.93, and 67.38; DLP: head χ2=28.82, 72.49, 47.72, 52.34, chest χ2=28.82, 35.95, 50.66, 41.64, abdomen χ2=45.53, 26.02 39.34, 44.24, P <0.05 ). Conclusions:The 75 th percentile values of CTDI vol and DLP for head, chest and abdomen in 4 children′s hospitals in Shanghai are lower or close to the values given in the relevant national standards and the diagnostic reference levels in some European countries, with higher DLP values on some scanning sites. The CT scanning procedures for paediatric patients needs to be further optimized.
ABSTRACT
Objective To explore the different apoptotic gene expressions and apoptotic signaling transduction of human rhabdomyosarcoma (RD) cells infected by enterovirus 71 (EV71) in different stage.Methods The survival of EV71-infected RD cells was observed by trypan blue staining.The apoptotic morphology and rates of RD cells were surveyed and detected by Annexin V-FITC/PI staining and flow cytometry,respectively.PCR array was employed to analyze 88 apoptotic gene expressions from EV71-infected RD cells at 8 h and 20 h postinfection (p.i),respectively.Results After RD cells were infected with EV71 (MOI =5) at 8 h p.i,the viability was significantly decreased.Flow cytometry data demonstrated that the apoptotic rates of EV71-infected RD cells had increased to 18.0％ and 19.1％ at 20 h p.i in early and later stage respectively.RT-PCR array studies revealed significant variations in the expression of apoptotic genes.Among 88 genes,only the expression of IFN-β1 was upregulated 5.22 folds,whereas 47 genes including ACIN1,Akt,Apaf1,caspase and CIDEB were found to be downregulated that were lower than 2 folds at 8 h p.i.However,28 genes including FasL,CD40L,TNF,caspase-10 and caspase-3 were induced more than 2 folds after EV71 infection at 20 h.Conclusion The downregulation of apoptosis-related genes is associated with viral apoptosis-suppressing effect in RD cells in the early stage of EV71 infection.The death receptor signaling pathways including Fas/FasL and TNF/TNFR are activated to induce cell apoptosis in the late stage of EV71 infection.Moreover,host cell can also inhibit apoptosis by regulating signal pathway of CD40/CD40L,NF-κB/RelA and PI3K/Akt activation.