Effect of nano-SiO_2 on the survival and PARP-1 expression in 16HBE cells / 中国职业医学

OBJECTIVE: To explore the effects of nano-silicon dioxide( SiO_2) on the survival and poly( ADP-ribose)polymerase-1( PARP-1) expression in human bronchial epithelial cells( 16 HBE cells). METHODS: i) The 16 HBE cells were treated with nano-SiO_2 at concentrations ranging from 0 to 100 mg/L for 24. 0 hours,and CCK-8 assay was used to examine cell viability. ii) The 16 HBE cells were divided into 6 groups: solvent control group( equal volume solvent treatment),micro-SiO_2 control group( treated with 20 mg/L micro-SiO_2),5,10,and 20 mg/L nano-SiO_2 groups( treated with the corresponding final dose of nano-SiO_2),and curcumin group. The curcumin group was given pretreatment with curcumin at a final concentration of 10 μmol/L for 2. 0 hours followed by treatment with a final concentration of 20 mg/L of nano-SiO_2. Cells in each group were harvested at time points of 4. 0,12. 0 and 24. 0 hours after treatment. The relative expression of PARP-1 mRNA and protein in 16 HBE cells was detected by quantitative real-time polymerase chain reaction and Western blotting respectively. RESULTS: i) The survival of 16 HBE cells decreased with increasing nano-SiO_2 treatment dose,showing a dose-effect relationship( P < 0. 01). ii) The expression of PARP-1 mRNA and protein in 16 HBE cells were dose-dependently decreased after nano-SiO_2 stimulation at the 12. 0 and 24. 0 hours time points( P < 0. 01). The expression of PARP-1 mRNA and protein in 5,10,and 20 mg/L nano-SiO_2 groups decreased at the above mentioned time points( P < 0. 05),compared with the solvent control group at the same time points. The expression of PARP-1 mRNA and protein in 20 mg/L nano-SiO_2 group was lower than that in the micro-SiO_2 control group at the same 12. 0 and 24. 0 hours time point( P < 0. 05). The above two indexes of cells were higher in curcumin group than that of 20 mg/L nano-SiO_2 group at the 12. 0 hours time point( P < 0. 05). CONCLUSION: Nano-SiO_2 stimulation can lead to decrease survival of 16 HBE cells in a dose-dependent manner and down-regulation of PARP-1 expression may be one of the mechanisms of proliferation and inhibition of 16 HBE cells induced by nano-SiO_2. Curcumin has certain protective effect on nano-SiO_2-induced 16 HBE cell injury.

Vitamin D nutritional status and its influencing factors in patients with smear-positive pulmonary tuberculosis in Shenzhen / 中华健康管理学杂志

Objective@#To determine the levels of vitamin D in patients with pulmonary tuberculosis in Shenzhen and identify the influencing factors of vitamin D levels and key groups of vitamin D deficiency, so as to provide a scientific basis for tuberculosis- and nutrition-related health education and promotion in Shenzhen.@*Methods@#Patients with smear-positive pulmonary tuberculosis who were diagnosed in 2016 were selected as the research subjects. Their relevant information and blood samples were collected, and the sample pool was established according to the inclusion criteria. One hundred and twenty patients were selected based on simple random sampling, including 84 men (70.0%) and 36 women (30.0%). Blood 25-hydroxyvitamin D [25(OH)D] concentrations were measured using chemiluminescence technology. Vitamin D statuses in patients were statistically described, and vitamin D levels in patients with different characteristics were compared. Multivariate linear regression analysis was performed to identify important factors influencing vitamin D levels in patients.@*Results@#Mean serum concentration of 25(OH)D in 120 patients was (40.2±16.0) nmol/L. There were 2 cases of vitamin D sufficiency (1.7%), 28 cases of vitamin D insufficiency (23.3%), and 90 cases of vitamin D deficiency (75.0%), of which 23 cases (19.2%) were of severe deficiency. 25(OH)D concentrations in patients with different lifestyles (indoors; indistinguishable indoors or outdoors; outdoors) were significantly different (35.3 nmol/L vs. 40.6 nmol/L vs. 49.5 nmol/L, F=8.274, P<0.001). Mean concentration of 25(OH)D in patients with sun exposure time of >30 min/d was higher compared to that in those with sun exposure time <30 min/d in the last month (46.4 nmol/L vs. 36.7 nmol/L, t=3.342, P=0.001). Multivariate linear regression analysis showed that the risk factors for 25(OH)D with statistical significance were Han ethnicity or not (β=-11.576, t=-1.991, P=0.049), housekeeping (including unemployment and retirement) or not (β=-6.136, t=-1.998, P=0.048), sun exposure time<30 min/d or none (β=-9.644, t=-2.829, P=0.006), body mass index (β=-2.056, t=-3.439, P=0.001) , and indoor degree of lifestyles (β=-4.419, t=-2.155, P=0.033).@*Conclusion@#Level of vitamin D is generally insufficient in patients with pulmonary tuberculosis in Shenzhen. It is necessary to strengthen health education related to vitamin D in patients with tuberculosis, especially in the high-risk population of vitamin D deficiency, such as in those with a lack of exposure to sunlight or high BMI.

Excessive selenium supplementation aggravates atopic dermatitis-like skin lesions induced by dinitrochlorobenzene in mice / 中华皮肤科杂志

Objective To evaluate the effect of micronutrient selenium on atopic dermatitis-like skin lesions in mice.Methods After 4-week feed with forages lacking selenium,40 BALB/c mice were randomly and equally divided into 4 groups:selenium deficiency group fed with forages containing 0.01 mg/kg selenium for 4 weeks,normal selenium supplementation group fed with forages containing 0.25 mg/kg selenium for 4 weeks,excessive selenium supplementation group fed with forages containing 3.00 mg/kg selenium for 4 weeks,and control group fed with forages containing 0.25 mg/kg selenium for 4 weeks.Then,atopic dermatitis-like skin lesions were induced by dinitrochlorobenzene (DNCB) in the mice in sensitized groups,including the selenium deficiency group,normal selenium supplementation group and excessive selenium supplementation group.During sensitization,the severity of dermatitis in mice was monitored.Three weeks after the sensitization,the total plasma IgE level and inflammatory cell count in whole blood were measured.Skin tissues from the back of mice were subjected to histopathological examination and the selenium level was detected.Statistical analysis was carried out by one-way analysis of variance for comparisons of IgE levels and cell counts among different groups,as well as by Pearson correlation analysis and linear regression analysis for analyzing the correlation of various indices with the selenium level.Results Six days after the sensitization,the dermatitis severity scores were significantly higher in the sensitized groups than in the control group (On day 6,8,11,13,15 and 18 after the sensitization,F =44.897,76.622,114.866,33.352,28.605 and 11.271 respectively,all P ＜ 0.01).On day 11 after the sensitization,the dermatitis severity score was significantly higher in the excessive selenium supplementation group than in the selenium deficiency group and normal selenium supplementation group (both P ＜ 0.05).Compared with the control group,obvious pathological changes of dermatitis were observed in the sensitized mice,but there was no significant difference in the number of inflammatory cells in skin lesions among the 3 sensitized groups (all P ＞ 0.05).The inflammatory cell count in whole blood and total plasma IgE level in the sensitized mice increased along with the increase of dietary selenium levels,and the excessive selenium supplementation group showed higher total plasma IgE level ([167.17 ±8.49] μg/L) compared with the selenium deficiency group ([124.78 ± 5.32] μg/L,t =3.919,P ＜ 0.05),normal selenium supplementation group ([132.61 ± 4.71] μg/L,t =3.222,P ＜ 0.05) and control group ([109.13 ± 0.79] μg/L,t =6.485,P ＜ 0.05).The selenium level in the skin tissues of sensitized mice was positively linearly correlated with the total plasma IgE level (r =0.579,P ＜ 0.001),whole-blood white blood cell count (r =0.414,P ＜ 0.05),neutrophil count (r =0.439,P ＜ 0.05),lymphocyte count (r =0.417,P ＜ 0.05)and eosinophil count (r =0.505,P ＜ 0.01).Conclusion Different dietary selenium levels showed different effects on the severity of dermatitis in mice,and more severe dermatitis occurred in the excessive selenium supplementation group.

Effect of SiO2 nanoparticles exposure on microRNA expression level in human bronchial epithelial cells / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of short and long term exposure to SiO2 nanoparticles on microRNA expression level in human bronchial epithelial cells(16HBE cells).</p><p><b>METHODS</b>The 16HBE cells were exposed to 5, 10, 15, 20, 25, 30 and 40 μg/ml SiO2 nanoparticles for 24 h to detect the cell viability by using CCK-8 assay. The inhibition rate of proliferation activity and half inhibitory concentration (IC50) were calculated. The 16HBE cells were exposed to 10 μg/ml SiO2 nanoparticles for 10 and 30 generations, named P10 and P30, and the control P0 was set. The cells were treated with SiO2 nanoparticles at 0, 1/4 IC50, 1/2 IC50 and IC50 concentration and μm-SiO2 at IC50 concentration for 24 h, and the control serum-free culture medium was set. Agilent miRNAs microarray chip was used to screen differentially expressed miRNAs in P10, P30 and P0 groups. The expression level of miRNA was detected by reverse transcription fluorescence quantitative polymerase chain reaction (qRT-PCR).</p><p><b>RESULTS</b>The inhibition rate of proliferation activity of 5, 10, 15, 20, 25,30,40 μg/ml group were (-3.33 ± 3.80)%, (20.40 ± 11.73)%, (39.08 ± 5.53)%, (55.10 ± 5.78)%, (66.42 ± 9.60)%, (71.67 ± 7.34)%, (81.43 ± 5.37)%, respectively; F=129.11, P<0.001. The IC50 (95%CI) was 18.35 (15.82-20.72) μg/ml. The expression level of miRNA-494-3p in P0, P10 and P30 were 1.00, 0.45 ± 0.08, 0.28 ± 0.07, respectively; F=60.77, P<0.001. miRNA-19a-3p were 1.00, 2.27 ± 0.45, 1.06 ± 0.19, respectively; F=30.05, P<0.001. miRNA-148b-3p were 1.00, 1.78 ± 0.29, 0.88 ± 0.19, respectively; F=30.23, P<0.001. Compared to control group, the expression level of miRNA-494-3p in 5, 10, 20 μg/ml SiO2 nanoparticles groups and 20 μg/ml μm-SiO2 group were 0.99 ± 0.04, 1.38 ± 0.19, 2.13 ± 0.14, 0.81 ± 0.25, respectively; F=57.03, P<0.001. miRNA-19a-3p were 0.91 ± 0.03, 1.12 ± 0.03, 0.53 ± 0.01, 0.86 ± 0.01, respectively; F=408.78, P<0.001. miRNA-148b-3p were 0.95 ± 0.02, 1.22 ± 0.00, 0.54 ± 0.02, 1.15 ± 0.04 respectively; F=264.14, P<0.001.</p><p><b>CONCLUSION</b>Short and long term exposure to SiO2 nanoparticles can affect the expression level of miRNAs in 16HBE cells. The expressions of miRNA-494-3p after long and short period exposure are different.</p>

Effect of silicon dioxide nanoparticles on expression and DNA methylation of PARP-1 gene in HaCaT cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of silicon dioxide nanoparticles on the expression and promoter region CpG islands methylation of (Poly [ADP-ribose] polymerase 1, PARP-1) gene in human HaCaT Cell.</p><p><b>METHODS</b>HaCaT Cells were treated with nm-SiO₂at 0, 2.5, 5 and 10 µg/mL and micro-SiO₂at 10 µg/ml for 24 h and DAC treatment was given at 10 µg/ml group for 48 h. Real-time PCR and western blot assay was used to detect the expression of PARP-1 mRNA and protein. BSP (Bisulfite Pyrosequence, BSP) assay was used to detect the promoter region CpG islands methylation status of PARP-1 gene.</p><p><b>RESULTS</b>After exposure to nano-SiO₂particles, compared to CTRL group, the mRNA and protein expression of PARP-1 in micro-SiO₂and 2.5 µg/ml group unchanged, but he mRNA and protein expression of PARP-1 in 5, 10 µg/ml as well as DAC group was down-regulated and there are statistical significance between CTRL group and 5, 10 µg/ml as well as DAC group and the PARP-1 promoter region CpG islands showed methylation.</p><p><b>CONCLUSION</b>nano-SiO₂can down-regulate PARP-1 expression in HaCaT Cell and this is associated with the change in the methylation of PARP-1 gene promoter region CpG islands induced by nano-SiO₂particles.</p>

COMPARISON OF METABOLIC BALANCE AND FECAL MORNITORING METHODS FOR ESTIMATING THE DIETARY ZINC ABSORPTION IN TIBETAN MEN / 营养学报

Objective: To compare the methods of metabolic balance (MB) and fecal monitoring (FM) for evaluating the dietary zinc (Zn) absorption in Tibetan men. Methods: In 14 d field trial on 16 adult Tibetan men, capsules of carmine were given to mark the feces from D4 to D12, and samples of diet, water, feces and urine were collected during the period. In addition, 4.0 mg zinc tracer (enriched with 67Zn) and 1.0 mg recovery indicator ytterbium (Yb) were orally administrated to the subjects in the evening meal of the D5. The ratio of 67Zn/68Zn in fecal samples was determined by inductively coupled plasma mass spectrometry, and then the zinc absorption was calculated based on the principle of isotope dilution. Results: The dietary zinc absorption in Tibetan men was (23.8?3.9) % evaluated by MB and (21.4?4.3) % by FM with significant difference (by paired-samples t test) and linear correlation (Pearson). The unabsorbed zinc tracer and Yb had the similar behavior through the digestive tract, mostly excreted within5 d following the intake. Conclusion: In the 14d metabolic period, the dietary zinc absorption from MB was a little higher than that from FM. Using FM, the metabolic period can be shortened to 4-5 days according to excretion of Yb. Both methods suggested that the dietary zinc absorption in the adult Tibetan men was good.

STUDY ON BIOAVAILABILITY OF DIETARY IRON, ZINC AND CALCIUM IN MALE ADULTS OF YI NATIONALITY / 营养学报

Objective: To study the absorption and utilization of dietary iron, zinc and calcium of male adults of Yi nationality, for basic information to prevent and cure diseases related to mineral deficiencies. Method: Twelve young men aged between 20 and 22 from the region lived by Yi nationality were studied in 14 d period with metabolic balance technique. At the beginning of study, their fasting blood hemoglobin and hematocrit, serum ferritin, plasma zinc and calcium concentration were deteimined. During the 4-12 d of the study, experimental diet, subsequent feces and urine samples were also collected for determining the contents of iron, zinc and calcium by flame atom absorption spectrum method, and then apparent absorption rate, apparent utilization rate and metabolic balance of these minerals were calculated. Results: The apparent absorption rate of iron, zinc and calcium was (15.8?6.2)%, (24.5?4.1)% and (32.3?9.7) % and the apparent utilization rate was (1.9?5.7)%, (12.8?4.3)% and (5.5?15.9)% respectively. The metabolic study showed iron balance, and zinc balance, but calcium balance was variable. Conclusion: The intakes of iron and zinc from the diet can meet the requirements, but calcium cannot. More intakes of foods rich in calcium are recommended for Yi nationality.