Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats

Objective To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride （50 mg/L NaF） and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals （four males and four females）. Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L NaF with a low dose of selenium-zinc preparation （0.1 mg/kg Na2 SeO3 and 14.8 mg/kg ZnSO4 · 7H2O）; and group four, 50 mg/L NaF with a high dose of selenium-zinc preparation （0.2 mg/kg Na2 SeO3 and29.6 mg/kg ZnSO4 · 7H20）. The activities of serum glutathione peroxidase （GSH-Px）, kidney superoxide dismutase （SOD）, and the levels of malondialdehyde （MDA） and glutathione （GSH） in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urine γ -glutarnyl transpeptidase （ γ -GT）, inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosls, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.

Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells

To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses （0.625, 1.25, 2.50, 5.00 pmol/L） for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of madl mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group. Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing madl mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

巩膜扣带术联合23G玻璃体切割术治疗眼球内异物伴视网膜脱离

目的:探讨巩膜扣带术结合23G玻璃体切割术对眼球内异物伴视网膜脱离的治疗效果。方法:将2014-01/2018-01收治的72例眼球内异物伴视网膜脱离患者以随机数字表法分为对照组36例和观察组36例,对照组行23G玻璃体切割术,观察组在对照组基础上行巩膜扣带术,观察两组术前、硅油取出3mo后眼压及视力变化、复位成功、复发情况及术后并发症发生情况。结果:术前两组眼压及BCVA均无差异(P>0.05),硅油取出后3mo,两组眼压及BCVA均较术前有明显改善(P<0.05),两组组间无差异(P>0.05);观察组与对照组一次手术解剖复位成功率分别为97%、81%(P<0.05),观察组与对照组复发率分别为6%、25%(P<0.05);观察组术后并发症发生率为22%,对照组31%(P>0.05)。结论:巩膜扣带术联合23G玻璃体切割术治疗眼球内异物伴视网膜脱离,可显著改善患者眼压及视力,提高复位成功率,减少复发,且安全性较高。

Abnormal Expression of Eukaryotic Translation Factors in Malignant Transformed Human Bronchial Epithelial Cells Induced by Crystalline Nickel Sulfide

Objective To study the oncogenic potential of mouse translation initiation factor 3 （TIF3） and elongation factor-1δ （TEF-1δ） in malignant transformed human bronchial epithelial cells induced by crystalline nickel sulfide （NiS）. Methods Abnormal expressions of human TIF3 and TEF-1δ genes in two kinds of NiS-transformed cells and NiS-tumorigenic cell lines were investigated and analyzed by the reverse transcript polymerase chain reaction （RT-PCR） and fluorescent quantitative polymerase chain reaction （FQ-PCR）, respectively. Results RT-PCR analysis primarily showed that both human TIF3 and TEF-1δ mRNA expressions in two kinds of NiS-transformed cells and NiS-tumorigenic cell lines were increased as compared with controls. FQ-PCR assay showed that the levels of TIF3 expressions in the transformed cells and tumorigenic cells were 3 and 4 times higher respectively, and the elevated expressions of TEF-16 eDNA copies were 2.7- to 3.5-fold in transformed cells and 4.1- to 5.2-fold in tumorigenic cells when compared with non-transformed cells, indicating that the over-expressions of human TIF3 and TEF-1δ genes were related to malignant degree of the cells induced by nickel. Conclusions These findings demonstrate that there are markedly abnormal expressions of TIF3 and TEF-1δ genes during malignant transformation of human bronchial epithelial cell lines induced by crystalline NiS. They seem to be the molecular mechanisms potentially responsible for human carcinogensis due to nickel.

Effects of Cadmium on Hepatocellular DNA Damage,Proto-Oncogene Expression and Apoptosis in Rats

Objective To study the effects of cadmium on hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats. Methods Cadmium chloride at the doses of 5, 10, and 20 μmol/kg was given to rats by i.p. and there were 5 male SD rats in each group. Hepatocellular DNA damage was measured by single cell gel electrophoresis （or comet assay）, while expression of proto-oncogenes c-myc, c-fos, and c-jun in rat hepatocytes were measured by Northern dot hybridization. C-Myc, c-Fos, and c-Jun were detected with immuno-histochemical method. Hepatocellular apoptosis was determined by TUNEL （TdT-mediated dUTP Nick End Labelling） and flow cytometry. Results At the doses of 5, 10, and 20 μmol/kg, cadmium chloride induced DNA damage in rat hepatocytes and the rates of comet cells were 50.20%, 88.40%, and 93.80%, respectively. Results also showed an obvious dose-response relationship between the rates of comet cells and the dose of cadmium chloride （r=0.9172, P〈0.01）. Cadmium chloride at the doses of 5, 10, and 20 μmol/kg induced expression of proto-oncogenes c-myc, c-fos, and c-jun. The positive brown-yellow signal for c-myc, c-fos, and c-jun was mainly located in the cytoplasm of hepatocytes with immunohistochemical method. TUNEL-positive cells were detected in cadmium-treated rat livers. Apoptotic rates （%） of cadmium-treated liver cells at the doses of 5, 10, and 20 μmol/kg were （17.24 ±2.98）, （20.58± 1.35）, and （24.06±1.77） respectively, being significantly higher than those in the control. The results also displayed an obvious dose-response relationship between apoptotic rates and the dose of cadmium chloride （r=0.8619, P〈0.05）. Conclusion Cadmium at 5-20 μmol/kg can induce hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats.

Over-expressed Genes Detected by Suppression Subtractive Hybridization in Carcinoma Derived From Transformed 16HBE Cells Induced by BPDE

To screen the over differentially expressed genes in carcinoma induced by BPDE-transformed 16HBE cells （16HBE-C cells）. Methods The suppression subtractive hybridization （SSH） method was performed to profile differentially expressed genes between 16HBE-C cells and 16HBE cells. The cDNA fragments of differentially expressed genes were inserted into TA cloning vector and transformed competent E. coli strain. Positive clones were randomly picked up and identified by the colony PCR method. Dot blot was used to test the same source with the tester. The differentially expressed cDNA fragments were sequenced and compared with known genes and EST database in Genbank. Results Eight known genes were over-expressed in 16HBE-C cells including eukaryotic translation elongation factor 1 alpha 1, HIF-1 responsive RTP801, ribosomal protein L10 （RPL10）, ribosomal protein S29 （RPS29）, mitochondrion related genes, and laminin receptor 1. Three differentially expressed cDNA fragments could not be matched to the known genes but to the EST database. Conclusion The SSH method can detect differentially expressed genes between 16HBE-C and 16HBE cells. BPDE-induced carcinogenesis may be related to alteration of at least eight known genes and three unknown genes. These expression data provide a clue to further cloning novel genes and studying functions in BPDE-induced carcinoma.

Development and multicenter validation of a nomogram for preoperative prediction of lymph node positivity in pancreatic cancer(NeoPangram)

Background:Neoadjuvant therapy is associated with nodal downstaging and improved oncological outcomes in patients with lymph node(LN)-positive pancreatic cancer.This study aimed to develop and validate a nomogram to preoperatively predict LN-positive disease.Methods:A total of 558 patients with resected pancreatic cancer were randomly and equally divided into development and internal validation cohorts.Multivariate logistic regression analysis was used to construct the nomogram.Model performance was evaluated by discrimination,calibration,and clinical usefulness.An independent multicenter cohort consisting of 250 patients was used for external validation.Results:A four-marker signature was built consisting of carbohydrate antigen 19–9(CA19–9),CA125,CA50,and CA242.A nomogram was constructed to predict LN metastasis using three predictors identified by multivariate analysis:risk score of the four-marker signature,computed tomography-reported LN status,and clinical tumor stage.The prediction model exhibited good discrimination ability,with C-indexes of 0.806,0.742 and 0.763 for the development,internal validation,and external validation cohorts,respectively.The model also showed good calibration and clinical usefulness.A cut-off value(0.72)for the probability of LN metastasis was determined to separate low-risk and high-risk patients.Kaplan-Meier survival analysis revealed a good agreement of the survival curves between the nomogram-predicted status and the true LN status.Conclusions:This nomogram enables the identification of pancreatic cancer patients at high risk for LN positivity who may have more advanced disease and thus could potentially benefit from neoadjuvant therapy.

Telomerase Activity and Telomerase Reverse Transcriptase Expression Induced by Selenium in Rat Hepatocytes

Objective To investigate the effects of sodium selenite on telomerase activity, apoptosis and expression of TERT, c-myc and p53 in rat hepatocytes. Methods Selenium at doses of 2.5, 5.0, and 10 μmol/kg was given to SD rats by garage. In rat hepatocytes, telomerase activity was measured by the telomeric repeat amplification protocol （TRAP）, apoptosis was detected by flow cytometry, and expressions of telomerase reverse transcriptase （TERT）, c-myc and p53 were analyzed by reverse transcription-polymerase chain reaction （RT-PCR）. c-Myc and P53 proteins were detected by immunochemistry. Results Selenium at doses of 2.5, 5.0, and 10 μmol/kg significantly increased hepatocellular telomerase activity and induced apoptosis in a dose-dependent manner. Although selenium at doses of 2.5, 5.0, and 10 μmol/kg displayed no obvious enhancing effect on the TERT mRNA expression in rat hepatocytes （P〉0.05）, it significantly increased the c-myc mRNA and p53 mRNA expression at the dose of 10 μmol/kg （P〈0.05）. Selenium at doses of 5.0 and 10 μmol/kg obviously increased the content of P53 protein in rat hepatocytes, but only at the dose of 10 μmol/kg, it significantly promoted the value of c-Myc protein in them. Conclusion Selenium can slightly increase telomerase activity and TERT expression, and significantly induce apoptosis and over-expression of c-myc and p53 at relatively high doses. The beneficial effects of selenium on senescence and aging may be mediated by telomerase activation and expression of TERT, c-myc, and p53 in rat hepatocytes.

HLA-DM Polymorphism and Risk of Trichloroethylene Induced Medicamentosa-like Dermatitis

Objective To establish the association between genetic polymorphisms of HLA-DMA and HLA-DMB and risk of developing trichloroethylene-induced medicamentosa-like dermatitis （TIMLD）. Methods Sixty-one cases were medically confirmed to have been affected with TIMLD and 60 controls were selected from exposed workers who were free from TIMLD The TIMLD cases and controls were similar in terms of age, sex, and duration of exposure. DNA was extracted both from the TIMLD cases and controls, HLA-DMA and HLA-DMB loci were amplified by using Touchdown PCR, and the alleles and genotypes were confirmed by restriction fragment length polymorphism （RFLP） and direct sequencing. Finally, the frequencies of HLA-DMA and HLA-DMB variants were compared between the two groups. Results The results showed that the frequency of HLA-DMA＊0101 and HLA-DMB＊0103 alleles was significantly increased in TIMLD patients than in controls （71.3% wv. 55.0% for HLA-DMA＊0101; P〈0.05） （11.5% vs. 3.3% for HLA-DMB＊0103; P〈0.05）. In addition, the frequency of HLA-DMA＊0102-＊0102 homozygous genotype was also significantly higher in the controls than in the patients （25.0% wv. 8.2%, P〈0.05）, whereas the frequency of heterozygous HLA-DMB ＊0101-＊0102 genotype was lower in the patients in comparison with the controls. Conclusion The polymorphisms of HLA-DM may be associated with the susceptibility to TIMLD.