Source Analysis of Ethylene Oxide Sterilization Residues in Medical Devices / 中国医疗器械杂志

At present, the most commonly used sterilization method for medical devices is ethylene oxide sterilization. The residue after sterilization is closely related to the health of the people who contacted with the medical devices. The study team analyzed the possible residues of medical devices after sterilization with ethyleneoxide. It is suggested that ethylene oxide, 2-chloroethanol and ethylene glycol should be evaluated comprehensively through the analysis of factors such as production links of medical devices, production process of ethylene oxide, sterilization process, sterilization environment and detection method.

2-Chloroethanol enhanced the expression of AQP4 protein in astrocytes via NMDAR/cAMP/PKA signaling pathway / 中国职业医学

OBJECTIVE: To investigate the role of N-methyl-D-aspartate receptor(NMDAR)/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA) signaling pathways in regulating 2-chloroethanol-induced aquaporin-4(AQP4) expression in astrocytes(AS). METHODS: i) AS in logarithmic growth phase were treated with 2-chloroethanol at the doses of 0.0, 7.5, 15.0 and 30.0 mmol/L for 12 hours, and the cells were collected for detection. ii) The AS in logarithmic growth phase were divided into blank control group, inhibitor control group, 2-chloroethanol group, and inhibitor intervention group. The inhibitor included dizocilpine(MK-801) and N-(2-[p-bromocinnamylamino-]ethyl)-5-isoquinolinesulfonamide(H89). The blank control group did not receive any treatment. The inhibitor control group was treated with a concentration of 10.0 μmmol/L MK-801 or 15.0 μmmol/L H89. The MK-801 intervention group was pretreated with MK-801 at a concentration of 10.0 μmmol/L for 30 minutes. The H89 intervention group was pretreated with H89 at a concentration of 15.0 μmmol/L for 1 hour. After the intervention, the AS in 2-chloroethanol group and MK-801, H89 intervention group were stimulated with 2-chloroethanol at a dose of 30.0 mmol/L for 12 hours. iii) The AS in each group were collected and used for Western blotting and real-time fluorescence quantitative polymerase chain reaction analysis to detect the protein and mRNA expression of AQP4, NMDAR receptor main subunit(NR1), NMDAR receptor 2 B subunit(NR2 B) and calmodulin dependent protein kinaseⅡ(CaMKⅡ). The Western blotting was adopted to detect the expression of phosphorylase-CaMKⅡ(p-CaMKⅡ) and PKA. Colorimetric method was used to detect the concentration of calcium(Ca~(2+)) in AS. The enzyme-linked adsorption test was used to measure adenylate cyclase(AC) activity and cAMP levels. RESULTS: i) The relative expression of protein and mRNA of AQP4, NR1 and NR2 B, PKA at protein level and CaMKⅡ at mRNA level, and the ratio of p-CaMKⅡ/CaMKⅡ protein, the concentration of Ca~(2+), AC activity and cAMP level in 30.0 mmol/L group were higher then those of 0.0 mmol/L group in AS(P<0.05). The relative protein expression of PKA and the concentration of Ca~(2+) increased with the increase of 2-chloroethanol(P<0.05). ii) The relative protein expression of AQP4 and the concentration of Ca~(2+) in the 2-chloroethanol group were higher than that of the blank control group and MK-801 control group(P<0.05). The relative protein expression of AQP4 and the concentration of Ca~(2+) in MK-801 intervention group were lower than that in 2-chloroethanol group(P<0.05). The relative protein expression of AQP4 and PKA in 2-chloroethanol group were higher than that of the blank control group and H89 control group(P<0.05). The relative protein expression of AQP4 and PKA in H89 intervention group was lower than that in 2-chloroethanol group(P<0.05). CONCLUSION: The 2-chloroethanol timulation induces the expression of AQP4 by activating NMDAR/cAMP/PKA signaling pathway in AS.