Gastritis

A 62-year-old man presents to the primary care physician with a several week history of worsening epigastric pain, dyspepsia, and intermittent vomiting. The patient reports taking omeprazole at home without relief of the symptoms. Past medical history includes coronary artery disease and hypertension, for which he takes aspirin and hydrochlorothiazide. Temperature is 37°C (98.6 °F), pulse is 72/min, respirations are 16/min and blood pressure is 132/62 mmHg. Physical exam shows mild tenderness on palpation of the epigastrium. The patient is instructed to discontinue the omeprazole for one week. After 1 week, an upper endoscopy is performed, revealing a single non-bleeding duodenal ulcer. Which of the following findings is most likely to be found on histologic analysis?