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COPD is a common, progressively disabling disease and a major health burden worldwide. Fourier transform infrared (FTIR) spectroscopy provides for sensitive analysis of complex biological samples. COPD pathogenesis involves quantitative and qualitative changes in sputum biosynthesis. This first study explores whether FTIR can produce distinct spectral profiles of human sputum, and capture differences between COPD and health. Sputum obtained from 15 COPD patients and 15 healthy volunteers was analysed using FTIR spectroscopy; differences in peak positions, height and configuration were identified and measured. All samples gave reproducible characteristic IR absorption spectra. The most relevant regions identified were the amide and glycogen rich regions, showing crucial spectral differences between health and COPD relating to peak position shifts or intensity alteration. These novel preliminary findings support further exploration of FTIR sputum profiling in a clinical study to determine its potential as a practical method for monitoring COPD.

Optical coherence tomography (OCT) offers great potential for clinical applications in terms of its cost, safety and real-time imaging capability. Improvement of its resolution for revealing sub-layers or sub-cellular components within a tissue will further widen its application. In this study we report that carbon pigment, which is frequently present in the lungs of smokers, could be used as a contrast agent to improve the OCT imaging of lung tissue. Carbon produced an intense bright OCT image at a relatively deep location. The parallel histopathological section analysis confirmed the presence of carbon pigment in such tissues. The underlying mechanism of the OCT image formation has been discussed based on a model system in which carbon particles were dispersed in agar gel. Calculations and in-depth intensity profiles of OCT revealed that higher refractive index particles with a size close to or smaller than the wavelength would greatly increase backscattering and generate a sharp contrast, while a particle size several times larger than the wavelength would absorb or obstruct the light path. The naturally occurring contrast agent could provide a diagnostic biomarker of lung tissue in smokers. Furthermore, carbon under such circumstances, can be used as an effective exogenous contrast agent, with which specific components or tissues exhibiting early tumour formation can be optically labelled to delineate the location and boundary, providing potential for early cancer detection and its treatment.

An ideal diagnostic system for the human airways should be able to detect and define early development of premalignant pathological lesions, to facilitate optimal curative treatment and prevent irreversible and/or invasive lung disease. There is great need for exploration of safe, repeatable imaging techniques which can run at real-time and with high spatial resolution. In this study, optical coherence tomography (OCT) was utilized to acquire cross-sectional images of upper and lower airways using fresh pig lung resections as a model system. Obtained OCT images were compared with parallel tissue characterization by conventional histological analysis. Our objective was to determine whether OCT differentiates the composite structural layers and inherent anatomical variations along different airway locations. The data show that OCT can clearly display the multilayered structure of the airways. The subtle architectural differences in three separate anatomical locations including trachea, main bronchus and tertiary bronchus were clearly delineated. Images of the appropriate anatomical profiles, with depth of up to 2 mm and 10 microm spatial resolution were obtained by our current OCT system, which was sufficient for recognition of the epithelium, subepithelial tissues and cartilage. In addition, the relative thickness of individual structural components was accurately reflected and comparable to histological sections. These data support OCT as a highly feasible, optical biopsy tool, which merits further exploration for early diagnosis of human airway epithelial pathology.

A method of determining a disease state of an animal by imaging a sample of at least a portion of a tissue of the animal by optical coherence tomography scanning and comparing optical coherence tomographical scanned image the histopathological images of a tissue type of the animal at various stages of disease state stored in a histopathological image database.

Purpose: Current diagnostic imaging modalities for human bronchial airways do not possess sufficient resolution and tissue penetration depth to detect early morphologic changes and to differentiate in real-time neoplastic pathology from nonspecific aberrations. Optical coherence tomography (OCT) possesses the requisite high spatial resolution for reproducible delineation of endobronchial wall profiling. Experimental Design: To establish whether OCT could differentiate between the composite microstructural layers of the human airways and simultaneously determine in situ morphologic changes, using a bench-top OCT system, we obtained cross-sectional images of bronchi from 15 patients undergoing lung resections for cancer. All scanned sections underwent subsequent detailed histologic analysis, allowing direct comparisons to be made. Results: OCT imaging enables characterization of the multilayered microstructural anatomy of the airways, with a maximum penetration depth up to 2 to 3 mm and 10-μm spatial resolution. The epithelium, subepithelial components, and cartilage are individually defined. The acquired OCT images closely match histologically defined patterns in terms of structural profiles. Furthermore, OCT identifies in situ morphologic changes associated with inflammatory infiltrates, squamous metaplasia, and tumor presence. Conclusions: Our results confirm that OCT is a highly feasible optical tool for real-time near-histologic imaging of endobronchial pathology, with potential for lung cancer surveillance applications in diagnosis and treatment.

Background Intercellular adhesion molecule-1 (ICAM-1) is a critical target-docking molecule on epithelial cells for 90% of human rhinovirus (HRV) serotypes. Two forms of ICAM-1 exist, membranous (mICAM-1) and soluble (sICAM-1), both expressed by bronchial epithelial cells. Interferon-gamma (IFN-γ), a crucial Th-1 immuno-regulatory mediator, can modulate mICAM-1 expression; however its simultaneous effects on mICAM-1: sICAM-1 levels and their consequent outcome on cell infectivity have not been previously explored. Methods Primary normal human bronchial epithelial cells were pre-stimulated with IFN-γ (1 ng/ml for 24 h) and subsequently inoculated with HRV-14 or HRV-1b (TCID50 10 2.5). Epithelial surface ICAM-1 expression and soluble ICAM-1 release were measured at the protein and gene level by immunofluorescence and ELISA respectively; mRNA levels were semi-quantified using RT-PCR. Molecular mechanisms regulating ICAM-1 isoform expression and effects on epithelial cell infectivity were explored. Results In IFN-γ-biased cells infected with HRV-14, but not HRV-1b, mICAM-1 expression is down-regulated, with simultaneous induction of sICAM-1 release. This differential effect on HRV-14 receptor isoforms appears to be related to a combination of decreased IFN-γ-induced JAK-STAT signalling and proteolytic receptor cleavage of the membranous form in IFN-γ-biased HRV-14 infected cells. The observed changes in relative mICAM-1: sICAM-1 expression levels are associated with reduced HRV-14 viral titres. Conclusion These findings support the hypothesis that in epithelial cells conditioned to IFN-γ and subsequently exposed to HRV-14 infection, differential modulation in the ratio of ICAM-1 receptors prevails in favour of an anti-viral milieu, appearing to limit further target cell viral attachment and propagation.