Robin Ghosal

BACKGROUND: Survival time for lung cancer is poor with over 90% of patients dying within five years of diagnosis primarily due to detection at late stage. The main objective of this study was to evaluate Fourier transform infrared spectroscopy (FTIR) as a high throughput and cost effective method for identifying biochemical changes in sputum as biomarkers for detection of lung cancer. METHODS: Sputum was collected from 25 lung cancer patients in the Medlung observational study and 25 healthy controls. FTIR spectra were generated from sputum cell pellets using infrared wavenumbers within the 1800 to 950 cm-1 "fingerprint" region. RESULTS: A panel of 92 infrared wavenumbers had absorbances significantly different between cancer and normal sputum spectra and were associated with putative changes in protein, nucleic acid and glycogen levels in tumours. Five prominent significant wavenumbers at 964 cm-1, 1024 cm-1, 1411 cm-1, 1577 cm-1 and 1656 cm-1 separated cancer spectra from normal spectra into two distinct groups using multivariate analysis (group 1: 100% cancer cases; group 2: 92% normal cases). Principal components analysis revealed that these wavenumbers were also able to distinguish lung cancer patients who had previously been diagnosed with breast cancer. No patterns of spectra groupings were associated with inflammation or other diseases of the airways. CONCLUSIONS: Our results suggest that FTIR applied to sputum might have high sensitivity and specificity in diagnosing lung cancer with potential as a non-invasive, cost-effective and high-throughput method for screening. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00899262.

STUDY OBJECTIVES: To assess prospectively the emotional content of dreams in individuals with the obstructive sleep apnea hypopnea syndrome (OSAHS) and sleepy snorers. METHODS: Prospective observational study. Forty-seven patients with sleepiness and snoring attending a sleep-disordered breathing clinic, completed a morning diary concerning pleasantness/unpleasantness of their dreams for 10 days, and then had AHI assessed by a limited-channel home sleep study. Participants and groups: Sleepy snorers, AHI < 5: n = 12 (mean age = 51.00 years [SD 7.01], 7 males); AHI 5 -14.9, n = 14 (mean age = 49.71 y [9.73], 12 males); AHI ≥ 15, n = 21 (mean age = 56.33 [11.24], 16 males). RESULTS: All groups reported similar numbers of dreams and nightmares during the diary period. The AHI ≥ 15 group were significantly higher on dream unpleasantness than were the sleepy snorers (p < 0.05); and when only males were analyzed, this difference was also significant (p = 0.01). As AHI increased across the 3 groups, there was a significant decrease in variability of dream emotions (Levene test for homogeneity of variance between the 3 groups, p = 0.018). Mean daytime anxiety and daytime depression were significantly correlated with mean dream unpleasantness and with mean number of nightmares over the diary period. CONCLUSIONS: Patients with AHI ≥ 15 had more emotionally negative dreams than patients with AHI < 5. The variation in mean dream emotion decreased with increasing AHI, possibly because sleep fragmentation with increasing AHI results in fewer and shorter dreams, in which emotions are rarer.