Diagnosis of Gastric Lesions From Exhaled Breath and Saliva

Number of patients that will have a definitive diagnosis and Alveolar exhaled breath samples collected from individuals with Tedlar® bags (Keika Ventures, LLC) after endoscopy.. Two breath samples were collected from each person tested. Two-bed sorption tubes filled with the following sorbents were used as traps for sample collection with simultaneous preconcentration: 100mg matrix Tenax TA and 50mg matrix Tenax TA (35-60 mesh; purchased from Supelo, Bellefonte, PA). Sorbents were separated by glass wool. The samples were collected at a total flow through sorption trap of 200ml/min. One sample was used for analysis with the nanosensors array, and the other sample was used for Gas Chromatography coupled with Mass Spectrometry (GC-MS) analysis. Cancer tissue and paracancerous tissue samples were collected in the process of surgical resection. After collection in the operating room, the samples were immediately placed in - 5 ℃ dry ice and transferred to the laboratory. Then, the samples were frozen in liquid nitrogen for 30 minutes, and then placed in - 80℃ freezer for cold storage. After that, the samples were divided into several batches and transported in dry ice for subsequent transcriptome analysis. All the saliva samples were collected using 2ml cryopreservation tube during early morning before surgery or endoscopic resection. The patient had been told not to eat after 22 o'clock the night, and not to drink water, smoke, brush teeth or exercise violently one hour before the collection. The saliva samples were sealed in the -80 C refrigerator after collection and then transported in a foam box equipped with dry ice, followed by UHPLC-MS analysis.