BACKGROUND:Reports have demonstrated that cytotoxicity produced by ferric oxide (Fe2O3) nanoparticles is associated with cellular lipid peroxidation. Whether Fe2O3 nanoparticles have toxicity to macrophages, and what is the association of toxic mechanism and oxidization?OBJECTIVE: To observe the effects of different concentrations of Fe2O3 nanoparticles on the oxidative damage of macrophages.DESIGN: A controlled observation experiment.SETTING: School of Public Health, Southeast University.MATERIALS: RAW264.7 cells were peritoneal macrophages of mouse and purchased from Shanghai Institute of cells, Chinese Academy of Sciences. Fe2O3 nanoparticles (30 nm) suspension was provided by Department of Biomedical Engineering, Southeast University). Fe2O3 nanoparticle suspension was placed in 60 ℃ water for 10 hours,then in 37 ℃ water overnight. This procedure was repeated 3 times for germicidal treatment. Then, the suspension was packed into small bottles and stored at 4 ℃ for later use. DMEM high glucose culture fluid (Gibco Company,USA); trypsinase (Difco Company, USA, imported); new-bom calf serum(Sijiqing Company, Hangzhou); hydrogen dioxide (H2O2, Gibco Company); Kits for measuring hydrogen dioxide(H2O2), hydroxy radical (·OH), superoxide anion radical (O2·-), lactic acid dehydrogenase, ultramicro ATP enzyme and Coomassie brilliant blue protein levels (Jiancheng Biotechnique Co., Ltd.,Nanjing).METHODS: This experiment was carried out in the laboratory of Department of Labor and Environmental Health, School of Public Health, Dongnan University between March 2006 and July 2006. RAW264.7 cells (Abelson murine leukemia virus-induced tumor) were cultured in DMEM (Gibco Company) containing 100 g/L fetal bovineserum, 100 000 U/L penicillin and 100 mg/L streptomycin in the environment of 5% CO2. Cell growth was observed under an inverted radical in the cells: 1.5×108 L-1 macrophages were inoculated to 24-well plate, 1 mLa well. After the macrophages were cultured for 24 hours in incubation at 37 ℃ in a humidified atmosphere containing 5% CO2. 1.070 0, 0.5350 and 0.2675 g/L Fe2O3 nanoparticles (30 nm) suspension-intervened macrophages were set as Fe2O3 nanoparticle group, and normal saline group was set as control group. Following the intervention of nanoparticles, macrophages were disrupted with Determination of the activities of lactate dehydrogenase (LDH), Na+-K+-ATPase and Ca2+-Mg2+-ATPase: Macrophages in the Fe2O3 nanoparticle group and control group were treated as above. The activities of LDH in culture medium were determined according to the instruction of reagent kit (Nanjing Jiancheng Bioengineering Co., Ltd). And the activities of Na+-K+-ATPase and Ca+-Mg2+-ATPase were also determined according to the instruction of reagent kit (Nanjing Jiancheng Bioengineering Co., Ltd) at low temperature. MAIN OUTCOME MEASURES: ①Effects of different concentrations of Fe2O3 nanoparticles on the production of H2O2, ·OH and O2·- in RAW264.7 cells.②Effects of different concentrations of Fe2O3 nanoparticles on the activities of LDH ,Na+-K+-ATPase and Ca2+-Mg2+-ATPase in RAW264.7 cell culture fluid.RESULTS: ① Level of ·OH free radical in Fe2O3 nanoparticle 0.267 5, 0.535 0, 1.070 0 g/L groups was higher than that in control group, respectively [(0.605±0.066), (0.410±0.080), (0.764±0.051), (0.285±0.057)mkat/g, P ＜ 0.05]; Level of respectively [(9.935±1.159), (8.912±0.131), (13.479±0.752), (5.635±0.475)μkat/g,P ＜ 0.05]; Level of H2O2 in Fe2O3 nanoparticle 1.070 0 g/L group was higher than that in the control group [(14.695±2.815), (2.397±0.399) mmol/L, P ＜increased (P ＜ 0.05). Fe2O3 nanoparticles had effects on the activities of Na+,K+-ATPase and Ca2+,Mg2+-ATPase. With the increase of dose of Fe2O3 nanoparticles, the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase were gradually decreased. There were significant differences as compared with control group (P ＜ 0.05)CONCLUSION:Increasing dose of Fe2O3 nanoparticles wouldcause more H2O2,·OH and O2·- free radicals in the cells, increase cell membrane permeability and inhibit the activities of LDH, Na+-K+-ATPase and Ca2+-Mg2+-ATPase.

OBJECTIVE: To detect the expression and relationship between somatostatin receptor 2 (SSTR2) and phosphorylated STAT3 (P-STAT3) in human olfactory neuroblastoma (ONB) and adjacent normal olfactory nerve tissue. METHOD: Immunohistochemical (IHC) staining was used to detect the expression of SSTR2 and P-STAT3 in tumor and adjacent normal olfactory nerve tissue from 11 ONB patients. RESULT: SSTR2 was mainly expressed in cell cytoplasm and the expression intensity was significantly stronger in tumor tissues than in adjacent normal tissues (P<0.01). P-STAT3 was mainly expressed in cell nuclear in tumor tissues. No expression was found in adjacent normal tissues. There was a negative correlation between the expression intensity of SSTR2 and P-STAT3 (r(s) = -0.367, P<0.05). CONCLUSION Lower expression of SSTR2 and activation of STAT3 in ONB cells might contribute to the development of ONB.
Adolescent ; Adult ; Esthesioneuroblastoma, Olfactory ; metabolism ; pathology ; Female ; Humans ; Male ; Middle Aged ; Nose Neoplasms ; metabolism ; pathology ; Receptors, Somatostatin ; metabolism ; STAT3 Transcription Factor ; metabolism ; Young Adult

Objective To investigate the features of native Hakka speakers' ability to identify Cantonese tones.Methods Twenty native Cantonese speakers and 12 native Hakka speakers were given the Hongkong Cantonese tone identification test.Results Neither group was troubled by similar vowel and consonant sounds.The Cantonese group could identify all tones well except distinguishing tones 5 and 2 (89％) and tones 4 and 6 (89％).The Hakkas had the most difficulty distinguishing tones 3 and 6 (70.0％),but significant differences were observed between the two groups in the identification of tones 2 and 5 and 2 and 4.Conclusion A native Hakka speaker's ability to identify Cantonese tones may be closely related to the tone's pitch,tonal patterns as well as the Hakka tone system.