Diagnosis of Gastric Lesions With Na-nose

• Discrimination between Malignant and Benign Gastric Lesions with Na-nose [ Time Frame: 2 weeks after the collection of breath ] [ Designated as safety issue: Yes ]
  Alveolar exhaled breath samples collected from 140 volunteers and 800 patients referred for upper endoscopy or surgery in Latvia were analyzed using a custom-designed array of chemical nanosensors based on organically functionalized gold nanoparticles and carbon nanotubes.Predictive models were built employing discriminant factor analysis (DFA) pattern recognition method. Classification accuracy, sensitivity and specificity were determined using leave-one-out cross-validation. The chemical composition of the breath samples was studied using gas chromatography coupled with mass spectrometry (GC-MS).
  
  

• Geographical comparison of VOCs between China and Latvia [ Time Frame: 2 weeks after the data analyses ] [ Designated as safety issue: Yes ]
  To make the comparison between the content of volatile organic compounds in the exhaled breath between the subjects in China and Latvia
  
  

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.