Objective To study the impact of sodium arsenite(NaAsO2) exposure on melanoma cells A375 (hereinafter referred to as the A375) and G361 (hereinafter referred to as the G361) pigment production and tyrosinase (TYR) activity and the differences of pigment metabolism capacity between the cell lines.Methods A375 and G361 cells were exposed to sodium arsenite at concentrations of 0.0(control),0.1 and 1.0 μmol/L for 72hours.Cell viability was measured by Alamar Blue assay.Melanin levels and TYR activity were measured at the same time.Results After exposure for 72 hours,the cells of 0.1 μmol/L dose groups of both of the two cell lines [A375:(103.32 + 1.26)％; G361:(104.10 + 1.76)％] showed a slightincrease of proliferation without significant differences compared with those of the control[A375:(100.00 ± 1.08)％; G361:(100.00 + 1.79)％,all P ＜ 0.05] ;while cell viability of the 1.0 μmol/L dose group of both of the two cell lines[A375:(75.32 ± 1.59)％; G361:(78.26 ± 2.10)％] were significantly lower than those of the control (all P ＜ 0.05).Melanin levels of G361 cell line [(7.19 ± 0.35),(7.34 ± 0.83),(8.19 ± 0.86)pg/cell] were significantly higher than that of A375[(4.35 ± 0.72),(4.54 ± 0.01),(4.60 + 0.59)pg/cell,all P ＜ 0.05] in all the three groups.TYR activity of G361 cell line [(54.13 ± 1.21),(54.56 ± 0.21),(56.25 ± 0.85)Bq] were also markedly higher than that of A375 cell[(42.00 ±0.21),(42.90 ± 0.54),(42.91 ± 0.01)Bq,all P ＜ 0.05] in all the three groups.The melanin levels and TYR activities of both of the two cells lines showed an increase tendency along with increased doses of arsenic exposure,but without significant differences when compared with those of the three groups (all P ＞ 0.05).Conclusions Arsenic related pigment disorder may be associated with increased melanin levels and TYR activities induced by arsenic exposure; individual difference of pigment metabolism may be associated with different basal melanin levels and TYR activity between different individuals.

Objective To investigate the effect of sodium fluoride(NaF) on proliferation, differentiation and the mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor κβ ligand (RAN KL) of mouse osteoblasts. Methods Osteoblasts were isolated from calvarias of Kunming mice born in 1 - 2 d and cultured. Various concentrations of NaF(0, 10-8, 10-7, 10-6, 10-5, 10-4, 10-3mol/L) were added to the culture medium, the proliferation and activity of alkaline phosphatase(ALP) was determined after 72 h or 120 h. The expression of OPG mRNA and RANKL mRNA was analyzed by semi-quantification RT-PCR. Difference among groups was analyzed by One-Way AN0VA. Difference between two groups was analyzed by LSD-t test. Results There was significant difference in cell proliferation among groups after 72 h(F = 13.806, P < 0.05). Compared with control group(0.434 ± 0.010) , the proliferation was significantly induced in 10-7 - 10-4 mol/L groups treated osteoblasts (0.448 ± 0.010, 0.453 ± 0.013, 0.454 ± 0.016, 0.449 ± 0.018, all P< 0.05), and was significantly suppressed in 10-3 mol/L group(0.401 ± 0.009, P < 0.05). There was statistic difference in the activity of ALP among groups(F = 9.021, P < 0.05). Compared with control group (1.677 ± 0.682), the activity of ALP significantly increased in 10-7 - 10-5 mol/L groups[ (2.447 ± 0.756) × 106, (2603 ± 0.183) × 106, (2.687 ± 0.886) × 106 U/L, P < 0.05 or P < 0.01 ] and significantly decreased in 10-4 mol/L group[ (1.479 ± 0.366) × 106 U/L, P < 0.05 ]. There was significant difference in the expression of OPG mRNA among groups(F = 11.299, P< 0.05). Compared with control group (1.000 ± 0.000), the expression of OPG mRNA was significantly increased in 10-7 - 10-4 mol/L groups( 1.058 ± 0.027, 1.053 ± 0.026, 1.088 ± 0.055, 1.069 ± 0.008, P < 0.05 or P < 0.01) , while significantly decreased in 10-3 mol/L group (0.941 ± 0.029, P< 0.05). There was no difference in RANKL mRNA expression among groups (F= 1.311, P> 0.05). The ratio of RANKL/OPG decreased with increasing doses of fluoride and increased in 10-4, 10-3 mol/L groups, but there was no difference between groups(F = 1.376, P> 0.05). Conclusions A biphasic pattern of proliferation and differentiation has been induced in mouse osteoblasts, which manifests stimulation effect in low doses and suppression in higher doses. Low doses of sodium fluoride suppress differentiation and maturation of osteoblasts by increasing expression of OPG mRNA, while high doses of sodium fluoride enhance differentiation and maturation of osteoblasts by decreasing expression of OPG mRNA.

Objective To observe the metabolism and distribution of arsenic in liver and brain of offspring rata by exposure to arsenic of pregnant rats or lactation dams and weaned pups,and explore if arsenic could penetrate the placental barrier,lactation barrier and blood brain barrier. Methods The Wistar female rots were randomly divided into four groups according to body weights,12 in each group,and were fed with drinking water that contained arsenic(NaAsO_2) 0,10,50,100 mg/L beginning from the gestafional day 6 until pups 42 days old. Pups were separately sacrificed on postnatal day(PND) 0,15,28,42. Arsenic in liver and brain of offspring rots and in breast milk was examined by atomic absorption speetrophotometer with an arsenic speeiation pretreatment system. Results Concentration of iAs,MMA,DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[0,0,0,(7.3±6.6),0,(44.2±27.4)ng/g]on PND 0,42[iAs: (120.0±46.0),(195.5±125.3),(216.5±278.4),(176.6±151.8) ng/g; M MA: (47.2±18.1),(199.6±389.1),(47.4±55.2),(82.7±79.2) ng/g; DMA: (984.3±377.4),(2222.1±1433.2),(998.1±368.3),(1781.3±715.7)ng/g,all P < 0.05]. Concentration of DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[(13.9±18.1),(50.6±98.3)ng/g]on PND 15,28 [(270.3±73.1),(323.9±72.7),(758.7±245.9),(1020.6±383.6) ng/g,all P < 0.05]. Concentration of iAs,DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group [(1.4±3.5),(49.7± 47.1),0,(100.4±30.2)ng/g]on PND 28,42 [iAs: (37.5±28.1),(268.8±246.4),(307.2±339.9),(15.4±9.4),(479.1±161.1),(408.4±51.9)ng/g;DMA: (594.5±148.8),(3181.9±519.0),(4834.2±2568.4),(1061.8± 85.2),(3697.1±553.7),(4120.0±732.8) ng/g,all P < 0.05]. Concentration of DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group[(13.2±20.5)ng/g]on PND 15[(182.0±60,2),(637.6±90.0),(1458.7±196.3)ng/g,all P < 0.05]. Concentration of arsenicals of liver and brain showed a dose-dependent increase. The concentrations of DMA of breast milk in 50,100 mg/L groups were also higher than that of 0 mg/L group[(9.8±13.4),0 ng/g]on PND 0,15 [(182.3±85.9),(372.2±203.9),(124.2±33.1),(244.4±196.5)ng/g,all P < 0.05]. In the analysis of the change of arsenic on different postnatal day,we found the concentration of iAs,MMA,DMA,TMA in liver and brain of pups all decreased on postnatal day 15,and was lower than that on PND 0,28 and 42. Conclusions The distribution of arsenic and methyl-metabolism in liver and brain of pups is related with arsenic exposure dose. Arsenic can penetrate the placenta and blood brain barrier easily and lactation can hinder arsenic intake in some extent.

Animals ; Arsenic ; toxicity ; Comet Assay ; DNA Damage ; drug effects ; Lymphocytes ; drug effects ; metabolism ; Male ; Malondialdehyde ; metabolism ; Rats ; Rats, Wistar ; Tobacco Smoke Pollution ; adverse effects

Objective To explore the effects of smoking and alcohol drinking on arsenic metabolism of people exposed to different concentrations of arsenic in drinking water.Methods Residents in Shanxi exposed to different concentrations of arsenic in drinking water and age ≥ 18 years old adults were chosen as the subjects for this study in 2008,the subjects were divided into three groups according to the concentrations of arsenic in drinking water: high-arsenic exposure group (more than 0.05 mg/L),low-arsenic exposure group (between 0.01 and 0.05 mg/L) and control group(less than 0.01 mg/L),excluded recently had eaten seafood and had poisoning symptoms of chronic arsenic in drinking water in the crowd.Smoking and alcohol drinking habits were investigated by questionnaire.Arsenic species in the urine samples were detected with hydride generation atomic absorption spectroscopy.Total arsenic(tAs) was the sum of iAs％,MMA％ and DMA％.iAs％,MMA％ and DMA％ were calculated as iAs/tAs,MMA/tAs and DMA/tAs,respectively.The first methylation ratio(FMR) and the secondary methylation ratio(SMR) were calculated as (MMA + DMA)/tAs and DMA/(MMA + DMA),respectively.Results Three hundred and ninety-five adults were chosen in this study.In the high exposure group the alcohol drinking and smoking subjects had higher MMA％(16.24％) but lower SMR(82.19％ ) than the non-drinking and non-smoking subjects (12.16％ and 86.13％,respectively).The differences of both MMA％ and SMR were significant(P ＜ 0.05 ).No significant difference was observed between the non-smoking/non-drinking subjects and the smoking or the drinking subjects(all P ＞ 0.05 ).In the low exposure group there were higher MMA％( 13.86％,13.99％) lower DMA％(72.87％,77.76％)and lower SMR (83.48％,83.90％ ) in those with smoking or drinking/smoking compared with the non-drinking and non-smoking subjects (11.83％,80.35％ and 86.54％,respectively,all P ＜0.05 ).No significant difference was observed between drinkers and non-drinking/non-smoking subjects(P ＞ 0.05).In the control group there were a higher MMA％( 17.27％,17.06％) lower DMA％ (73.89％,72.29％) and lower SMR (81.48％,82.58％ ) in those with smoking or drinking/smoking compared with the non-drinking and nonsmoking subjects( 11.52％,79.68％ and 87.19％,respectively,all P ＜ 0.05).No significant difference was observed between drinkers and the non-drinking/non-smoking subjects (all P ＞ 0.05).ConclusionThe arsenic methylation capacity of people with drinking and smoking is poorer than that of non-drinking and non-smoking subjects after arsenic exposure.

ObjectiveTo study the state of oxidative injury induced by sodium arsenite(NaAsO2) in SV-40-immortalized normal uroepithelial (SV-HUC-1 ) cells.Methods SV-HUC-1 cells were exposed to different concentrations of NaAsO2[0(control),1,2,4,8,10 μmol/L] for 24 h,intracellular reactive oxygen species (ROS) was determined by flow cytometry,and the content ofintracellular nitrotyrosine(NT) and the 8-Hydroxydeoxyguanosine (8-OHdG) levels of cell culture medium were detected by enzyme linked immunosorbent assay (ELISA).Results After 24 h treatment,ROS levels(81.76 ± 4.91,95.23 ± 2.17,126.61 ± 17.95,126.74 ± 27.77,114.18 ± 9.65) of SV-HUC-1 cells in the 1,2,4,8,10 μmol/L NaAsO2 exposure groups were significantly higher than those of the control group (69.84 ± 1.28,P ＜ 0.05 or ＜ 0.01 ),ROS levels and exposure dose were positively correlated significantly(r =0.818,P＜ 0.01); the content of NT in the 10 μmol/L NaAsO2 exposure group[(919.66 ± 206.33) μg/L] was significantly higher than that in the control group[ (238.19 ± 38.28)μg/L,P ＜ 0.01 ],NT content and dye concentrations of arsenic also had dose-response relationship (r =0.617,P ＜ 0.01); after 24 h the cells were treated with arsenic,no significant difference of 8-OHdG content in the culture medium was observed(F =2.127,P ＞ 0.05 ).ConclusionNaAsO2 can cause SV-HUC-1 cell oxidative damage.

Arsenites ; toxicity ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Keratinocytes ; cytology ; Skin ; cytology ; Sodium Compounds ; toxicity

Objective To observe the distribution and metabolism of arsenic speciation in urine of rats exposed to different concentrations of dimethylaraenic acid (DMA) through drinking water.Methods Thrity six weaning Wistar rats were randomly divided into normal control,low-dose group and high-dose group,12 rats in each group(6 female and 6 male); average body weight of female rats was (60 ± 5)g,and male rats was (50 ± 5)g.All rats of the 3 groups were given DMA at concentrations of 0,100,200 mg/L,respectively,corresponding to their specific groups through drinking water for 10 weeks.Inorganic arsenic(iAs),monomethylarsenic acid(MMA),DMA and trimethylarsenic compound (TMA) in urine were measured by hydride generation trapping and ultrahypothermia coupled with atomic absorption spectrometry.Results After feeding for 10 weeks,the differences of rat urinary concentrations of iAs,MMA,DMA and TMA between normal control,low-dose group and high-dose group were statistically significant(x2 =25.441,25.942,25.751,17.767,all P＜ 0.01).Urinary concentrations of iAs,MMA and DMA(2.541,4.383,24.447 mg/L) of low-dose group were significant higher than those of normal control (0.784,0.000,0.743 mg/L,all P ＜ 0.05) ; iAs,MMA,DMA and TMA(3.978,7.186,35.112,4.518 mg/L) of high-dose group were significantly higher than those of normal control(0.784,0.000,0.743,0.000 mg/L,all P ＜ 0.05).The concentrations increased along with increasing doses of DMA concentrations in drinking water(all P ＜ 0.05).Conclusions After rats are exposed to DMA,most of the DMA are excreted in unchanged form in urine and a small portion of DMA is metabolized into TMA.

To explore the expression of livin gene in acute non-lymphocytic leukemia (ANLL) cells and its clinical significance, the mRNA level of livin gene in 46 ANLL adult patients were measured by using reverse transcription polymerase chain reaction (RT-PCR). Other 10 healthy adults were selected as normal controls (NC), HL-60 cell line was employed as positive control. The results showed that the mRNA level of livin gene in ANLL patients was significantly higher than that in NC, while it decreased in patients with complete remission (CR). In relapsed patients, the level of livin mRNA increased again. In ANLL patients, the CR rate of patients with livin positive was lower than that of patients with livin negative (p<0.05). It is concluded that overexpression of livin gene may play a synergic role in the pathogenesis of ANLL and associates with CR rate in ANLL. It seems that high expression of livin gene may be used as a marker of poor prognosis in acute non-lymphocytic leukemia.
Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adolescent ; Adult ; Aged ; Biomarkers, Tumor ; genetics ; metabolism ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Leukemia, Myeloid, Acute ; genetics ; Male ; Middle Aged ; Neoplasm Proteins ; genetics ; metabolism ; Prognosis ; RNA, Messenger ; genetics ; metabolism ; Young Adult

Quality education and innovative ability cultivation of students are a new position in higher education.Exploring exper- iment was applied in teaching of microbiological experiment for enhancing integrative diathesis and cultivating innovative spirit and ability of students.The practice has been proved that learning fervor of students was increased adequately.Unaided operation abili- ty,integrative analysis ability and innovative idea were enhanced,too.Accordingly,teaching quality of microbiological experiment was improved.