system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 63-year-old man with inoperable esophageal carcinoma undergoes palliative chemoradiotherapy. Four hours after his first infusion of carboplatin and paclitaxel, he develops nausea and 3 episodes of vomiting and dry heaving. This adverse reaction is caused by stimulation of a brain region on the floor of the fourth ventricle. Chemotherapeutic drugs are able to stimulate this region because of the absence of a cell junction that is composed of which of the following proteins?
assistant
Claudins and occludins