Multi-generational impacts of arsenic exposure on genome-wide DNA methylation and the implications for arsenic-induced skin lesions.

As a nonmutagenic human carcinogen, arsenic (As)'s carcinogenic activity is likely the result of epigenetic changes, particularly alterations in DNA methylation. While increasing studies indicate a potentially important role for timing of As exposure on DNA methylation patterns and the subsequent differential risks for As toxicity and carcinogenesis, there is a lack of research that tackles these critical questions, particularly in human based populations. Here we reported a family-based study including three generations, in which each generation living in the same household had a distinctive timing of As exposure: in adulthood, in utero and during early childhood, and in germlines exposure for grandparents, parents, and grandchildren, respectively. We generated genome-wide DNA methylation data for 18 As-exposed families, nine control families, as well as 18 arsenical skin lesion patients. Our analysis showed that As exposure may leave detectable DNA methylation changes even though exposure occurred decades ago, and the most significant changes of global DNA methylation were observed among patients afflicted with arsenical skin lesions. As exposure across generations shared common differentially methylated DNA loci and regions (744 DML and 15 DMRs) despite the distinctive exposure timing in each generation. Importantly, based on these DML, clustering analysis grouped skin lesion patients together with grandparents in exposed families in the same cluster, separated from grandparents in control families. Further analysis identified a number of DML and several molecular pathways that were significantly distinguished between controls, exposed populations, as well as skin lesion patients. Finally, our exploratory analysis suggested that some of these DML altered by As exposure, may have the potential to be inherited affecting not only those directly exposed but also later generations. Together, our results suggest that common DML and/or DMRs associated with an increased risk for disease development could be identified regardless of when exposure to As occurred during their life span, and thus may be able to serve as biomarkers for identifying individuals at risk for As-induced skin lesions and possible cancers.

Biomarkers of arsenic exposure in arsenic-affected areas of the Hetao Basin, Inner Mongolia.

Seventy saliva samples, seventy urine samples, seventy nail samples, seventy hair samples, eight drinking water samples and ninety-three crop samples were collected from four villages of the Hetao Basin in Inner Mongolia to determine arsenic (As) exposure biomarkers and evaluate relationship between As uptake and human health risk. Trivalent As (As(III)), pentavalent As (As(V)), dimethylarsinic acid (DMA), arsenobetaine (AsB) and monomethylarsonic acid (MMA) were found in all urine samples. Only As(III) and As(V) were detected in saliva samples. In nail and hair samples, DMA, MMA, As(III) and As(V) were observed. Based on total As contents in crops and drinking water, the local residents' daily intake of total arsenic (TDIAs), the hazard quotient (HQ), and the cancer risk (R) were assessed. Male, older and cases of skin lesion participants generally had higher As contents in saliva, urine, nail and hair samples in relative to others. Salivary, urinary, nail and hair As were not significantly affected by body mass index (BMI) and smoking. Good correlations were observed between TDIAs and salivary, urinary, nail and hair As, showing that saliva, urine, nail and hair samples can be used as biomarkers of As exposure. Individually, levels of arsenicosis were positively correlated with TDIAs. The relationship between TDIAs and prevalence of arsenicosis concluded that, although As levels in crops and drinking water did not exceed national standards, they still pose a potential threat to human health. It was suggested that the maximum permissible levels of crop As and drinking water As should be re-evaluated for protecting human health.

Evaluating long-term attachment of a novel endoclip in porcine stomachs: a prospective study of initial deployment success and clip retention rates at different regions of the stomachs.

BACKGROUND AND AIMS: Through-the-scope endoscopic clips are widely used. Several designs of endoscopic clips are marked for different applications. However, no prior reports have been published to aid in comparing success rates of clip deployment and the retention rates at different regions of the stomachs. The aims of the article were to compare success rates of clip deployment and the retention rates at different regions of the stomachs with a novel endoclip. METHODS: Upper endoscope was inserted into the stomach of five pigs under general anesthesia. In all animals, three regions of the stomachs (gastric fundus, gastric body, and gastric antrum) were chosen as the sites of clip application. Two clips of a novel type were placed along the same gastric site at a distance of 0.5-1 cm from each other. Animals had weekly endoscopies to quantitate clip retention. RESULTS: Success rates of clip deployment were 70% for gastric fundus, 100% for gastric body, and 100% for gastric antrum. Clip retention rates were significantly higher with gastric body than with gastric fundus or gastric antrum at 1-8 weeks. CONCLUSIONS: (1) For the clip device, it seems that it is difficult for the clip deployment in gastric fundus (70%) than that in the gastric body or gastric antrum (100%), but there is no statistical significance (χ (2) test, p = 0.21). (2) Clips used in the gastric body were retained significantly longer than that in the gastric fundus or gastric antrum. (3) The novel clips were safe, and no complications such as bleeding or weight loss were noted.

Regulation of demethylation and re-expression of RASSF1A gene in hepatocellular carcinoma cell lines treated with NCTD in vitro.

BACKGROUND: Hepatocellular carcinoma, a lethal malignant neoplasm with poor prognosis, has dismal results of surgical resection and chemoradiotherapy. Norcantharidin (NCTD), the demethylated analog of cantharidin derived from a traditional Chinese medicine, Mylabris, has been used in the treatment of cancer. However, the detailed mechanisms underlying this process are generally unclear. PURPOSE: The aim of this study was to investigate the mechanism of NCTD-induced apoptosis in HepG2 cells. MATERIALS AND METHODS: Human HepG2 cell lines were treated with NCTD at different concentrations (2.50, 5.00, 10.00, 20.00, 40.00 µg/mL) for 24 hours. Cell proliferation was evaluated by measurement of cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The methylation levels of RASSF1A (Ras-association domain family 1 A) in HepG2 cells were detected by methylation-specific PCR (MSP). The mRNA levels of RASSF1A in HepG2 cells were detected by real-time fluorescent quantitative PCR (RT-PCR). The levels of RASSF1A protein expression of HepG2 cells were detected by Western blotting assay. RESULTS: The inhibition of cell proliferation was observed when treated with NCTD at concentrations (2.5 µg/mL), and as concentration increased, the proliferation of HepG2 cells was markedly inhibited by NCTD in dose-dependent manners. The levels of methylation of RASSF1A decreased at the increasing concentration of 10, 20 and 40 µg/mL. The levels of RASSF1A mRNA and protein were decreased when treated with NCTD at the concentrations of 10, 20 and 40 µg/mL, which were also in a dose-dependent manner. CONCLUSION: NCTD can reverse the methylation state of RASSF1A gene and induce its re-expression, which will provide the theoretical basis for the clinical practice.

Gastric outlet obstruction caused by benign anastomotic stricture: treatment by fluoroscopically guided balloon dilation.

PURPOSE: To evaluate the clinical efficacy and safety of fluoroscopically guided balloon dilation of gastric outlet obstruction caused by benign anastomotic stricture. MATERIALS AND METHODS: Fluoroscopically guided balloon dilation was performed on 17 patients with gastric outlet obstruction caused by benign anastomotic stricture. Fourteen patients underwent surgery for malignant disease and three patients for complication of benign gastric ulcer. The sites of anastomotic stricture were gastrojejunal (n = 12) or gastroduodenal (n = 5). An upper gastrointestinal (UGI) series was performed just following and 1 month after balloon dilation to evaluate both the clinical success of the procedure and any complications. A dietary intake was evaluated by using the score for patients with malignant dysphagia and the pre- and postballoon dilation scores were analyzed with the Wilcoxon signed rank test. RESULTS: In all patients, fluoroscopically guided balloon dilation was performed in one (n = 15) or two (n = 2) sessions and was technically and clinically successful (100%). The diameters of the balloon catheters used were 15 mm (n = 4), 20 mm (n = 14), and 25 mm (n = 1 mm; mean, 19.5 mm) in a total of 19 sessions. All patients had significant improvement of their levels of dietary intake (P < .001). Two of the 17 patients required the second procedure due to recurrent symptom nine and 15 months, respectively, after initial balloon dilation. Overall, 16 patients (94%) showed good results and no recurrence during a mean follow-up period of 13.5 months (range, 5-39 months). There were no major complications associated with balloon dilation. CONCLUSION: Fluoroscopically guided balloon dilation seems to be effective and safe for patients with gastric outlet obstruction caused by benign anastomotic stricture. Achieving a luminal diameter of 20 mm seems to be necessary to prevent recurrence of symptoms.

Benign duodenal strictures: treatment by means of fluoroscopically guided balloon dilation.

Fluoroscopically guided balloon (15 or 20 mm in diameter) dilation was performed on eight patients with benign duodenal strictures caused by peptic ulcers (n = 6), Crohn's disease (n = 1), and postoperative adhesion (n = 1). The procedure was technically and clinically successful without complications in seven of the eight patients (88%). Duodenal perforation occurred immediately after 20-mm-diameter balloon dilation in one patient who underwent emergency surgery. During the mean follow-up of 30 months (range, 2-103 months), there was recurrence in two of the seven patients (29%) who then underwent surgery. The other five patients (71%) showed good results with no recurrence.

Colorectal anastomotic strictures: treatment by fluoroscopic double balloon dilation.

PURPOSE: To evaluate the therapeutic efficacy and complications of fluoroscopically guided double balloon dilation for treatment of colorectal anastomotic strictures. MATERIALS AND METHODS: Under fluoroscopic guidance, 17 patients with colorectal anastomotic strictures underwent transanal double balloon dilation. Thirteen of 17 strictures were the consequence of surgery for malignant disease and the other four were secondary to surgery for benign disease. Sixteen of 17 patients had difficult or frequent defecation caused by partial obstruction. In the remaining one asymptomatic patient, the stricture was detected by endoscopy and barium enema after total proctocolectomy and a temporary ileostomy for ulcerative colitis. The therapeutic efficacy and complications were evaluated during the follow-up. RESULTS: Seventeen patients underwent double balloon dilation in a single session. The diameter of the first balloon was 20 mm and the second balloon's diameter was 10, 15, or 20 mm. Technical success was achieved in all 17 patients. After balloon dilation, complete (n = 12, 71%) or incomplete (n = 5, 29%) improvement of symptoms was achieved in all patients. Major complications such as perforation or severe hemorrhage did not occur. During the mean follow-up period of 23 months (range, 1-62 months), one patient (6%) developed a recurrent stricture and required a second session of double balloon dilation 6 months after initial balloon dilation. CONCLUSION: Fluoroscopically guided double balloon dilation is an effective and safe method for the treatment of colorectal anastomotic strictures.