Human epidermal growth factor receptor-2 gene expression positivity determined by silver in situ hybridization/immunohistochemistry methods and associated factors in a cohort of Sri Lankan patients with gastric adenocarcinoma : a prospective study

Objective: Positive human epidermal growth factor 2 (HER2) expression and its predictive clinicopathological features remain unclear in Sri Lankan gastric cancer (GC) patients. Here, we aimed to determine GC HER2 status predictors by analyzing associations between clinicopathological features and HER2 expression using immunohistochemistry (IHC) and silver in situ hybridization (SISH). Methods: During this 4-year prospective study, clinicopathological data were collected from participants in the National Hospital of Sri Lanka. HER2 IHC and SISH were performed using commercial reagents. Using chi-square tests, associations of HER2-IHC/SISH with clinicopathological features were analyzed. Results: Overall, 145 GC patients were included, 69 had gastrectomies and 76 had biopsies. Positive HER2 expression by IHC was associated with age 5/high-power field, with additional perineural invasion and lymphovascular invasion in resections. These features, excluding lymphovascular invasion but including male sex, were associated with HER2 expression by SISH. Conclusions: Age <60 years, high nuclear grade, tumor necrosis, and perineural invasion are associated factors of HER2 status. These could be used to triage GC patients for HER2 status testing in limited resource settings where IHC/SISH analysis is costly

Removal of heavy metals from mining impacted water by an electrocoagulation-ultrafiltration hybrid process

In this study, the use of an electrocoagulation-ultrafiltration (EC-UF) hybrid system for the treatment of mining impacted wastewater was investigated. A model wastewater solution containing copper, lead, cadmium and other constituents representative of mining impacted wastewater was used in this investigation. The effects of key operational parameters including electrolysis time, current density, and solution pH on the performance of the EC and EC-UF systems were systematically investigated. The removal rates of copper and lead by the EC process were consistently higher than that of cadmium. It is probable that the removal mechanism of cadmium was different from that of the base metal copper and lead. Results reported here indicate that an EC-UF hybrid system could be very effective in removing heavy metals at high solution pH. At an acidic condition, the removal efficiency of heavy metal by both EC and UF reduced dramatically. However, the overall removal efficiency by the hybrid EC-UF system remained quite high. Results reported here suggest that EC and UF can complement each other very well for optimum removal efficiency