Humans ; Occupational Diseases ; epidemiology ; prevention & control ; Occupational Health Services

Archives ; Humans ; Occupational Health

AIM:To study the blocking effect of shRNA on the expression of PSMA gene in LNCaP cell line by using shRNA eukaryotic expression vector.METHODS:Three pairs of DNA templates coding shRNA,synthesized against PSMA and cloned into the vector pSilencer 2.1-U6-neo,which was named pSilencer 2.1-U6-neo-shRNA,were identified by restriction endonuclease digestion analysis and DNA sequencing.LNCaP cells were then transfected with these three pSilencer 2.1-U6-neo-shRNAs and the negative control pSilencer 2.1-U6-neo-NC.After G418 selection,the cells were selected and the interfering effect was detected by RT-PCR and Western blotting.The biological behaviours of the transfected LNCaP cells were also tested.RESULTS:Restriction endonuclease digestion analysis and DNA sequencing results all showed that the 3 target segments were cloned into pSilencer 2.1-U6-neo vector respectively.After transfected into LNCaP cells,the inhibitory ratio of PSMA mRNA was 33.15%,9.26% and 41.97% respectively,and that of PSMA protein was 26.26%,6.47%,40.69% respectively.The p-shRNA3 was chosen to test the cell growth and its invasive power in vitro.The results showed that after interfering,the invasiveness of LNCaP cells were enhanced.CONCLUSION:The vector-based shRNA on PSMA gene effectively knocks down the PSMA gene expression.The successful construction of PSMA shRNA makes it possible for further study of the interaction between PSMA and prostate cancer.

Twelve populations of Inula lineariifolia were used as materials to measure morphological characteristics, photosynthetic parameters and chemical constituents. It aims to provide a theoretical basis for germplasm resources evaluation. The results showed that I. lineariifolia had relatively rich morphological diversity, there were significant differences of morphological characteristics, photosynthetic parameters and chemical constituents among populations. There was positive correlation on morphological characteristics and P(n). Twelve populations were divided into three-type. The three populations of Xuyi, Mingguang and Fengyang were of narrower-longer leaf, bigger biomass,better photosynthetic and higher chemical constituents. Then they were classified for a similar group. It proved that the three populations were more suitable for cultivation and promotion.
Biomass ; China ; Flowers ; chemistry ; growth & development ; metabolism ; Inula ; chemistry ; classification ; growth & development ; metabolism ; Photosynthesis ; Plant Leaves ; chemistry ; growth & development ; metabolism ; Plant Stems ; chemistry ; growth & development ; metabolism

Objective:To compare the durability of resin-based root-surface coating material and all-in-one self-etching adhesive on root surface in vitro.Methods:Human extracted premolars or molars with intact roots were selected.The cementum was removed using a periodontal scaler to expose root dentin. The root surface was coated with an acid-resistant nail varnish,leaving a window of 3 mm ×3 mm on the exposed dentin.The window was covered with either PRG Barrier Coat (PRG)or Clearfil S3 Bond (CS3).After water aging for 14 d,specimens were immersed in acid buffer at pH 4.5 for 4 d and the demineralization buffer was changed every 24 h.Then the specimen was split longitudinally through the center of the ‘window’and the cross-sectional surface was observed with scanning electron microscope (SEM).After fixed and dehydrated,the prepared samples were coated with platinum.The coating mate-rial,root dentin and the interface was observed by scanning electron microscope (SEM).The thickness of the coating material was measured on the SEMimages.Regarding toothbrush wear test,coronal dentin-disks were prepared and covered with PRG and CS3,respectively.After storage in water for 24 h,the specimen was subjected to the toothbrush wear tester for 100,200,300,500,700,1 500 brushing cy-cles.A slurry of fluoride toothpaste (1 ∶2 ratio of toothpaste and deionized water by weight)was used and the brushing load was 300 N.The surface microstructure of remaining coating material was analyzed using SEM.The wear depths were determined by a profilometer.Statistical analysis was performed with SPSS 20.0 by one-way ANOVA.The level of significance was at 0.05.Results:Application of PRG Barrier Coat produced a coating layer of (47.1 ±27.3)μm,while CS3 presented a thin film of (5.7 ± 2.1)μm in thickness.The exposed dentin was hermetically sealed and no obvious gap was observed at the interface in both PRG and CS3 groups.There was no dentin demineralization observed in both groups after water aging.The wear depths of PRG and CS3 increased along with the numbers of brushing cycles. PRG wore at a significant lower pace than CS3 did (P <0.05).Conclusion:PRG coating resin had similar performances as CS3 on protecting root dentin from demineralization after water aging.What’s more,PRG demonstrated a higher toothbrush wear resistance than CS3.We concluded that PRG Barrier Coat contained S-PRG filler may be an effective coating material for protecting exposed root from both chemical and mechanical challenges.Further studies should be carried out to evaluate the long-term reli-ability of the rootsurface coating materials under the clinical setting.

BACKGROUND: When the teeth affected abnormal biting force, tooth absorption and periodontium would be greatly damaged. OBJECTIVE: To study whether periodontal membrane fibroblast affected apoptosis following cyclic tensile stress stimulation and whether p38MAPK signaling pathway participated in apoptosis. METHODS: Fibroblasts at passages from 4 to 7 were randomly assigned to control, loading and SB203580 groups after synchronization. In the loading and SB203580 groups, 12% strain was applied at a loading frequency of 6 cycles per minute, i.e. 5 seconds for tension and 5 seconds for relaxation. In the SB203580 group, cells were treated with 20 mmol/L p38MAPK inhibitor SB203580 at 1 hour before loading. At 6, 12 and 24 hours after loading, cells from each group were harvested, and cell apoptosis was detected using a flow cytometry. Expression of bax mRNA was determined using reverse transcription-polymerase chain reaction. RESULTS AND CONCLUSION: Compared with the control group, apoptotic rate of fibroblasts and bax mRNA expression were increased after loading (P < 0.05), and enhanced over time, and peaked at 12 hour following loading, and then decreased gradually. Compared with the loading group, cell apoptosis was reduced at corresponding time points in the SB203580 group (P < 0.05), and bax mRNA expression was diminished. These results indicated that cells affected apoptosis after mechanics stimulation, and mitogen activated protein kinase p38MAPK signaling pathway participates in the process of apoptosis.

Objective To explore the DNA damage in peripheral blood lymphocytes of rats exposed to sodium arsenite. Methods Thirty-two Wistar rats, weighing 180 - 200 g, equal male and female, were randomly divided into 4 groups, 8 in each group. Sodium arsenite 0(control) ,0.05,0.15,0.45 mg/L were given through drinking water for 30 days. Body weight and drinking water consumption were measured every day. Blood were collected and DNA damage in peripheral blood lymphocytes was examined by single cell gel electrophoresis.Results The increase of body mass[( 121.00 ± 38.57), ( 120.62 ± 42.80), ( 125.38 ± 48.68)g]and water intake [(36.9 ± 6.2), (37.9 ± 5.8), (39.3 ± 4.2)ml/d]in 0.05,0.15,0.45 mg/L sodium arsenite groups were compared with the control group[( 119.25 ± 47.27)g, (38.4 ± 5.1 )ml/d], and the difference were not significant (F = 0.040,0.828, all P ＞ 0.05). The tail ratios[46.25%(185/400) ,57.00%(228/400),64.00%(256/400)], tail lengths [(32.89 ± 17.18), (58.74 ± 36.28), (77.55 ± 35.73 ) μm]and tail moments [(6.29 ± 3.74), ( 11.20 ± 9.64),(17.30 ± 12.60)μm]in 0.05,0.15,0.45 mg/L sodium arsenite groups were significantly higher than those of the control group[39.25%(157/400), (18.73 ± 15.83),(2.61 ± 1.05)μm, all P ＜ 0.01], and the tail ratios,tail lengths and tail moments in lymphocytes increased with increased doses of arsenic concentration. Conclusions Low doses of arsenic exposure can induce DNA damage in peripheral blood lymphocytes of rats.

Objective To study the correlation between pulse pressure(PP) and cardiovascular structure and function in aged patients with essential hypertension. Methods Forty-eight aged patients with essential hypertension were enrolled into the study and divided into the following two groups by the mean value of PP: PP

Objective To investigate the regularity and predictors of weight loss during concurrent chemo-radiotherapy for nasopharyngeal carcinoma patients. Methods A retrospective study was carried out on 82 patients with nasopharyngeal carcinoma ,with average age of 45 years ,who received concurrent chemoradiotherapy at the Affiliated Cancer Hospital of Guangzhou Medical University. Paired t-test was used to analyze the weight loss pattern during chemoradiotherapy. The Spearman′s rank correlation analysis was used to investigate the correlation between high weight loss(HWL)and the clinical factors. Results The paired t-test showed that the weight of the patients decreased continuously every week during chemoradiotherapy(P < 0.05),and the value dropped most significantly during the 4th week. Among these 82 patients,32 were determined as HWL(weight loss > 10%). Spearman′s rank correlation analysis showed that HWL was associated with older age,female,higher T and TNM stage,3D-CRT technology,the higher dose of radiotherapy in nasopharynx and in neck lymph node,and decreases of leukopenia and hemoglobin over degree Ⅱ(P<0.05). Conlousions Weight may decrease continuously every week during chemoradiotherapy for nasopharyngeal carcinoma patients. Age,gender,T stage,TNM stage,radio-therapy dose,and leukopenia and hemoglobin decreases may be predictors for weight loss degree during concurrent chemoradiotherapy for nasopharyngeal carcinoma patients.

OBJECTIVETo explore the role of histone H3 acetylation in cleft palate induced by 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD) in C57BL/6J mice, and its mechanism.

METHODSOn gestation day 10 (GD10), 36 pregnant mice were randomly divided into two groups as the treated group(n = 18) and the control group( n = 18). The mice in the treated group received intragastric administration with TCDD 28 μg/kg, while the mice in the control group received equivalent corn oil. The pregnant mice were sacrificed on GD13. 5, GD14. 5 and GD15. 5, collecting fetal palates to determine the activities of histone acetyltransferases (HATs) by Colorimetric and the expression level of acetylated histone H3 (Acetylated histone H3, Ac-H3) by Western-blot.

RESULTSThe activity of HATs was 0.409 7 ± 0.0147, 0.522 3 ± 0.017 1 and 0.643 5 ± 0.013 9 in control group on GD13.5, GD14.5 and GD15.5; 0.865 0 ± 0.0129, 0.719 1 ± 0.017 8 and 0.551 2 ± 0.016 8 in TCDD group. The activity of HATs in TCDD group was higher than that in control group on GD13. 5, GD14. 5, showing significantly difference between the two groups (t = - 56. 932, t = - 19. 516, P < 0.01); however, the activity of HATs in TCDD group was significantly lower than that in control group on GD15. 5 (t = 10. 382, P < 0.01). The expression level of Ac-H3 was 0.745 0 ± 0.113 5, 1.055 9 ± 0.249 4 and 1.795 5 ± 0.081 9 in control group on GD13. 5, GD14. 5 and GD15. 5; while 1.4490 ± 0. 1460, 1. 641 8 ± 0.099 7 and 1. 512 1 ± 0. 150 2 in TCDD group. The expression of Ac-H3 in TCDD group was higher than that in control group on GD13. 5, GD14. 5, showing significantly difference( t = -6. 593, -3. 779, P <0. 01, P <0.05) ; However, the expression of Ac-H3 in TCDD group was statistically lower than that in control group (t = 2. 870, P <0. 05).

CONCLUSIONThe acetylation of histone H3 was involved in the cleft palate of C57BL/6J mice induced by TCDD, which may be one of the mechanisms in TCDD-induced cleft palate.

Acetylation ; drug effects ; Acetyltransferases ; metabolism ; Animals ; Cleft Palate ; chemically induced ; metabolism ; Dioxins ; Female ; Fetus ; Histones ; metabolism ; Humans ; Mice ; Mice, Inbred C57BL ; Polychlorinated Dibenzodioxins ; Pregnancy ; Random Allocation ; Teratogens