Drug-induced sleep endoscopy while administering CPAP therapy in patients with CPAP failure

Study objectives: To study the pattern of upper airway collapse in patients with CPAP failure by performing DISE while administering CPAP therapy and to determine the reason for CPAP failure accordingly. Methods: This observational retrospective study comprised 30 patients diagnosed with OSA and CPAP failure, who underwent DISE while administering CPAP therapy. During DISE, the upper airway was assessed with and without CPAP therapy using the VOTE classification. Additionally, a jaw thrust maneuver was performed, in order to mimic the effect of an additional mandibular advancement device (MAD) in combination with CPAP therapy. Consequently, the outcome of DISE was translated into a clinically relevant categorization. Results: Eleven patients (37%) had a persistent anteroposterior (AP) collapse, including a collapse at velum, tongue base, or epiglottis level and multilevel collapse. Eight patients (27%) had a floppy epiglottis. Five patients (17%) had a persistent complete concentric collapse (CCC) and three patients had a persistent laryngeal collapse (10%). In three patients (10%), no airway collapse was found after CPAP administration. Conclusions: Based on the results of the reported study, in most cases, the potential cause of CPAP failure can be determined by this new diagnostic method. Consequently, suggestions can be made for additional therapy

All-trans retinoic acid induced gene expression and growth inhibition in head and neck cancer cell lines

Retinoids are natural and synthetic analogues of vitamin A and have proven activity in various types of cancer. As for head and neck squamous cell cancer (HNSCC), retinoids are especially active in leukoplakia and in preventing second primary cancers. The aim of this study was to assess the growth inhibiting activity of all-trans retinoic acid (all-trans RA) in a panel of six head and neck squamous cell cancer cell lines and to correlate this response to the mRNA expression of factors related to differentiation and receptor mediated signal transduction. Three lines showed minimal, two moderate and one strong growth inhibition after 72 h exposure to all-trans RA. Three lines with a dissimilar response were selected for further studies, the measurement of mRNA expression by northern blotting. It was found that neither the expression nor the induction of retinoic acid receptor (RAR) -α and -γ and retinoic X receptor-α mRNA was related to sensitivity. The mRNA expression of RAR-β was too low to be measured in the three cell lines. The most sensitive cell line was, however, the only one that expressed mRNA of squamous differentiation markers. These data suggest a relationship between the retinoid sensitivity profile and the degree of cellular differentiation

Monitoring microcirculatory alterations in oral squamous cell carcinoma following photodynamic therapy

Background One of the mechanisms through which photodynamic therapy (PDT) is thought to elicit tumour destruction is by producing microvascular damage and obstruction of nutritive blood flow. The aim of this study was to directly monitor and quantify microcirculatory changes following tissue illumination by PDT for oral squamous cell carcinoma. Methods Ten consecutive patients receiving PDT for a carcinoma in situ, a T1 or T2 tumour in the oral cavity without evidence of lymph node metastasis were selected for this study. Tumour and marginal healthy mucosa total capillary density (TCD) and functional capillary density (FCD) inside the field of illumination were measured and compared using sidestream dark-field (SDF) imaging prior to tissue illumination, immediately after PDT, and again after 15 min. Results Baseline mean tumour TCD was 21.2 ± 5 capillaries per square millimetres (cpll/mm2) and 24.9 ± 19 cpll/mm2 in the surrounding marginal healthy tissue; there were no significant differences between tumour and healthy tissue or time points. Comparisons between baseline and post-illumination time points revealed significant differences in both tumour and healthy tissue FCD (P < 0.05). No significant differences in FCD were observed between the two tissues. Conclusions Our findings using SDF imaging demonstrate that PDT significantly attenuates tumour and marginal healthy tissue perfusion by directly disrupting the functionality of the microcirculation