Gastric tissue specimens used in this study were obtained from 20 H. pylori-infected subjects who underwent GI tract endoscopy in two public hospitals in the State of Nariño, Colombia that are located in two areas with contrasting gastric cancer risks. The individuals included in this study were randomly selected and represent part of a larger series of subjects that has been described previously.9 (link) All participants provided informed consent. The protocol was approved by the Committees on Ethics of Universidad del Valle and Hospital Departmental in Nariño, Colombia and by the Institutional Review Board at Vanderbilt University. All personal identifiers were removed prior to receiving specimens and were coded.
Expression of p53/ARF was assessed by immunohistochemistry using p53 (DO-1) and p14ARF (4C6/4) antibodies and detected using EnVision+HRP kit (DakoCytomation, UK). Immunohistochemial staining was evaluated for intensity and staining frequency in the nuclear compartment of superficial gastric epithelium. The intensity of staining was graded as 0 (negative), 1 (weak), 2 (moderate) or 3 (strong). The frequency was graded according to the percentage of positive cells. Total scores were calculated by multiplying the intensity score by the percentage of positive cells.
Expression of p53/ARF was assessed by immunohistochemistry using p53 (DO-1) and p14ARF (4C6/4) antibodies and detected using EnVision+HRP kit (DakoCytomation, UK). Immunohistochemial staining was evaluated for intensity and staining frequency in the nuclear compartment of superficial gastric epithelium. The intensity of staining was graded as 0 (negative), 1 (weak), 2 (moderate) or 3 (strong). The frequency was graded according to the percentage of positive cells. Total scores were calculated by multiplying the intensity score by the percentage of positive cells.
