Clinical Research Directory

Inclusion Criteria: 1. Male and female subjects 21-30 years of age 2. At baseline health with no recent illnesses or medical conditions that would preclude enrollment as assessed by the Principal Investigator 3. Ability to understand a written informed consent form and comply with the requirements of the study. 4. E-cigarette use for more than 6 months preceding the date of enrollment and less than a 5 pack year smoking history (e-cigarette users) OR less than a 5 pack year smoking history (non-smoker group). 5. No diagnosis of any lung disease (pre-bronchodilator FEV1/FVC normal on the day of screening defined by \> 95thCI of NHANES III, ATS/ERS guideline) Exclusion Criteria: 1. History of any lung disease 2. Control (non-smoking) group: History of illegal drug use by inhalation 3. History of CNS disease including stroke and dementia, end-stage liver disease, coronary artery disease, renal failure 4. Acute infection of any kind in the previous 6 weeks 5. Pregnancy or a possibility of pregnancy 6. Anemia 7. Inability to undergo MR imaging based on the standard clinical criteria for MRI