The organochlorine p,p′-dichlorodiphenyltrichloroethane induces colorectal cancer growth through Wnt/β-catenin signaling

Dichlorodiphenyltrichloroethane (DDT), an organochlorine pollutant, is associated with several types of cancer. However, the relationship between DDT and colorectal cancer is uncertain. In this study, the impact of p,p′-DDT on colorectal cancer growth was evaluated using both in vitro and in vivo models. Our results indicated that the proliferation of human colorectal adenocarcinoma DLD1 cells was significantly promoted after exposed to low concentrations of p,p′-DDT ranging from 10⁻¹² to 10⁻⁷ M for 96 h. Exposure to p,p′-DDT from 10⁻¹⁰ to 10⁻⁸ M led to upregulation of phospho-GSK3β (Ser9), β-catenin, c-Myc and cyclin D1 in DLD1 cells. RNA interference of β-catenin inhibited the proliferation of DLD1 cells stimulated by p,p′-DDT. Inhibiting of estrogen receptors (ERs) had no significant effect on the action of p,p′-DDT. Treatment with p,p′-DDT induced production of intracellular reactive oxygen species (ROS) and inhibited superoxide dismutase (SOD) activity in DLD1 cells. Treatment with N-acetyl-L-cysteine (NAC), a ROS inhibitor, suppressed the induction of Wnt/β-catenin signaling and DLD1 cell proliferation by p,p′-DDT. Moreover, in a mouse xenograft model, 5 nmol/kg p,p′-DDT resulted in increased tumor size, oxidative stress and Wnt/β-catenin signaling. These results indicated that low concentrations of p,p′-DDT promoted colorectal cancer growth through Wnt/β-catenin signaling, which was mediated by oxidative stress. The finding suggests an association between low concentrations of p,p′-DDT exposure and colorectal cancer progression.     

微量全血彗星试验检测电子制造业不同工种人群DNA损伤

目的:研究电子行业不同工种职业人群的DNA损伤情况,为确定健康危害预防重点提供依据。方法:选择珠三角某电子厂在职工人563名作为职业接触组,其中铅暴露组(n167),异丙醇组(n287),噪声组(n39),铅+高温组(n34),异丙醇+高温组(n36);选取就业前体检工人作为对照组(n90)。采集人体微量外周血进行彗星试验,运用倒置荧光显微镜拍摄彗星图片,并通过CASP彗星分析软件对彗星图片进行分析。结果:铅+高温组工人外周血的核DNA含量低于对照组(P<0.05),尾DNA含量、尾长和尾矩高于对照组(P<0.05);异丙醇+高温组工人外周血的核DNA含量低于对照组(P<0.05),尾DNA含量、尾长、彗星全长、尾惯量和尾矩高于对照组(P<0.05)。结论:本研究所选取的电子行业各工种工人均有明显的DNA损伤情况,尤以异丙醇+高温组工种最为严重,其次是铅+高温组工种,应引起职业病防治管理机构和厂方的特别关注。     

Concentrations of arsenic,cadmium and lead in human hair and typical foods in eleven Chinese cities

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45 mg kg⁻¹, respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51–65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food.     

A clinician's guide to the treatment of foot burns occurring in diabetic patients

IntroductionDiabetes mellitus affects 25.8 million Americans and is predicted to almost double by 2050. The presence of diabetes complicates hospital courses because of the microvascular complications associated with disease progression. Patients with diabetes represent 18.3% of annual burn admissions to our unit and 27% have burns to the feet. The purpose of this project was to develop an evidence-based guideline for care of the patient with diabetes and foot burnsMethodsA multidisciplinary group was charged with developing an evidence-based guideline for the treatment of foot burns in patients with diabetes. Evidence was evaluated in the areas of diabetes, burn care, hyperbaric medicine, care of diabetic foot wounds and physical therapy. After guideline development and approval, key aspects were incorporated into order sets.ResultsKey aspects of this guideline are the ability to identify patients with undiagnosed diabetes, assess diabetic control, optimize glycemic and metabolic control, optimize burn wound management, treat microvascular disease, and provide education and a discharge plan. Evaluated outcomes are glycemic control, length of stay, complication rates, amputation rates, infection rates and the use of hyperbaric oxygen.ConclusionsBest outcomes for this high risk population will be attainable with an evidence based guideline.