ABSTRACT
Background The association between serum nickel (Ni) and oral cancer incidence is unclear and most of the previous studies were observational studies that did not control for confounding factors between groups. Objective To assess the correlation of serum Ni with oral cancer incidence based on propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). Methods A cohort of 456 newly diagnosed oral cancer patients was recruited from the First Hospital of Fujian Medical University during November 2011 to May 2019, and residents ordered their health check-up in hospitals or local community health centers over the same period were selected as a control group, which included a total of 1410 participants. Serum Ni was evaluated by inductively coupled plasma mass spectrometry. Case-control pairs were selected using a 1:1 PSM (caliper value of 0.02), and the study subjects in the case group and control group were weighted for subsequent analysis by IPTW. The general characteristics of the study subjects were tested for equilibrium before and after matching by chi-square test and standardized mean difference (SMD). This was followed by exploring the potential nonlinear dose-response relationship between serum Ni and oral cancer using restricted cubic splines as well as analyzing the association between serum Ni and oral cancer incidence by conditional logistic regression and weighted logistic regression. Results After controlling for between-group covariates by PSM and IPTW, the dose-response curves demonstrated that the risk of developing oral cancer tended to decline and then increase with the increasing serum Ni level. The outcome of the analysis using PSM demonstrated that as compared to the control group, the risk of developing oral cancer in the 0.09-16.80 μg·L−1 serum Ni group was negatively correlated with serum Ni level (OR=0.36, 95%CI: 0.24-0.54), whereas the risk of developing oral cancer in the >16.80 μg·L−1 serum Ni group was positively correlated with serum Ni level (OR=5.43, 95%CI: 2.76-10.68). After applying IPTW, a negative association was found between the risk of oral cancer and serum Ni concentration within a serum Ni window ranging from 0.09 to 20.55 μg·L−1 (OR=0.39, 95%CI: 0.29-0.52), while a positive association with an OR and 95%CI of 5.54 (3.62-8.49) for the Ni concentration > 20.55 μg·L−1. Conclusion In this study, a J-shaped relationship between serum Ni concentration and the risk of developing oral cancer is found, which shows that high serum Ni concentration (>20.55 μg·L−1) may be a risk factor for oral cancer.
ABSTRACT
<p><b>BACKGROUND AND OBJECTIVE</b>The p53 as a transcription factor in cell stress was activated to regulate cell cycle and programmed cell death to inhibit tumor growth. Usually, p53 is kept in non-activated state through various mechanisms, including the action of p53 C-terminal negative regulatory sequences. The purpose of the study is to prepare the two types p53 recombinant adenoviruses that carry full-length p53 as well as deletion of negative regulatory sequences at p53 C-terminus and to detect exogenous GFP expression in human lung cancer cell infected-virus by FCM scatter plot.</p><p><b>METHODS</b>Using pAdEasy-Track vector system the p53 recombinant plasmids was constructed and the homologous recombinants in E. coli was produced. The three kinds of recombinant adenovirus in L293 cells was generated, sequencing proved. Exogenous GFP expression in human lung cancer 801D cells infected-virus was detected by FCM scatter plot.</p><p><b>RESULTS</b>p53 recombinant adenoviruses named Ad-p53(wtp), Ad-p53(del) and Ad-(empty carrier) were produced. Results of sequences indicate that the Ad-p53(del) was deletion of 111 bases before stop codon TGA and of 3 untranslated region at p53, the Ad-p53(wtp) no loss of any p53 base, the Ad-(empty carrier) no p53 sequence. FCM scatter plot indicate the percentage of 801D cells expressed GFP with three kinds of viral infection was almost same and was increased with the virus density. 801D contains ratio of cells with different fluorescence intensity.</p><p><b>CONCLUSION</b>The preparation of recombinant adenovirus, Ad-p53(del), pA-p53(wtp) and Ad-(empty carrier). The cells expressed-GFP can be quantitatively detected by FCM scatter plot. It was provide that the reliability of the virus system and accurate method for selecting viruses density to infecting cells.</p>
Subject(s)
Animals , Humans , Mice , Adenoviridae , Genetics , Flow Cytometry , Methods , Genes, p53 , Green Fluorescent Proteins , Genetics , Recombination, GeneticABSTRACT
The "free" and "bound" forms of cholinc in food were determined by a rapid method in which extraction and hydrolysis were accomplished simulta- neously with a barium hydroxide-methanol-chloroform mixture. The choline was isolated by adsorption on a Florisil column. By passing ammonium rei-neckate through the column, a pink band of choline reineckate was formed. The choline reineckate could be eluted by acetone and its concentration was determined by measuring the absorbance of eluate of the reineckate band by spectrophotometer at 526nm.This method is accurate, rapid, easy to handle. The RSD is 2.43%. The recoveries of added choline ranged from 96.7% to 101.7%.