Patients with Epiglottic Collapse Are Less Adherent to Autotitrating Positive Airway Pressure Therapy for Obstructive Sleep Apnea.

Rationale: The anatomic orientation of the epiglottis is such that it points in the opposite direction to inspiratory flow, thereby potentially making positive airway pressure (PAP) treatment challenging in patients with epiglottic collapse. However, no previous studies have analyzed PAP adherence in these patients. Objectives: This study aimed to analyze adherence to autotitrating PAP (APAP) treatment in patients with epiglottic collapse. Methods: We performed an age- and sex-matched case-control study. On the basis of their overnight level-I polysomnogram, patients were prescribed APAP in a tertiary hospital between July 2018 and March 2019. The site of airway collapse was diagnosed with drug-induced sleep endoscopy. Demographic factors, sleep questionnaire, polysomnography, and APAP usage statistics were analyzed. Results: Eighteen patients with epiglottic collapse (epi-group) and 36 without epiglottic collapse (control group) were analyzed. We found that 22.8% of patients in the epi-group terminated APAP within 2 weeks, whereas only 2.8% of patients in the control group terminated APAP within 2 weeks (P = 0.048). The percentage of days with usage over 4 hours was significantly lower in the epi-group (64.6% vs. 75.6%; P = 0.008). In addition, the adherence failure rate was 66.7% in the epi-group and 33.3% in the control group (P = 0.039). Patients with epiglottic collapse were also found to have lower body mass index, which is an unfavorable predictor of APAP adherence. Conclusions: This study suggests that patients with epiglottic collapse have a higher APAP adherence failure rate than patients without epiglottic collapse. Thus, patients with epiglottic collapse should be followed closely during treatment, and alternative therapies should probably be considered for these patients.

Comparison of long-term treatment outcomes of T2N0M0 laryngeal squamous cell carcinoma using different treatment methods.

Early [stage I and II (T2N0M0)] laryngeal cancer types are currently recommended to be treated with a single modality, consisting of definitive radiation therapy or larynx-preserving surgery. Although the treatment outcomes of stage I are good, the frequency of successful outcomes decreases with T2N0M0. Therefore, the present study investigated the treatment outcomes of different treatment methods in T2N0M0 laryngeal cancer. In total, 83 patients with previously untreated T2N0M0 laryngeal squamous cell carcinoma were enrolled. Patients were grouped by treatment method: Radiation therapy (RT; 27 patients); chemoradiotherapy (CRT; 46 patients) with cisplatin base; and surgery-based therapy (SBT; ten patients). The recurrence rates of the RT, CRT and SBT groups were 44.4, 19.6 and 50%, respectively. Moreover, the local control rates of the RT, CRT and SBT groups were 55.6, 87.0 and 80%, respectively. The CRT group had a significantly lower recurrence rate and higher local control rate compared with the RT group (P<0.05). In the survival analysis, overall and disease-specific survival rate did not differ significantly among the treatment groups. However, 3- and 5-year disease-free survival rates (DFS) of the RT group were both 55%, those of the SBT group were both 50% and those of the CRT group were both 80%. Furthermore, the DFS was significantly higher in CRT group compared with the other groups (P=0.02). Using multivariate analysis with Cox regression, it was found that the treatment method was the most important factor for DFS and had a significant impact in the CRT group. In addition, in patients with glottic cancer with anterior commissure and subglottic invasion, the CRT group had significantly improved DFS compared with the RT group, whereas there was no significant difference between the two groups in patients without subglottic invasion. According to National Cancer Institution Common Toxicity Criteria (version 5.0), more patients had toxicity in the CRT group compared with the RT group. However, in the RT and CRT groups, no patients demonstrated mortality due to toxicity, and treatment-related toxicities were manageable. Collectively, although definitive conclusions could not be established, due to the limitations of this retrospective study, the results suggest that CRT had a positive impact on the local control and DFS rates with manageable toxicity in patients with T2N0M0 laryngeal cancer.

Feasibility of a 3D-printed anthropomorphic patient-specific head phantom for patient-specific quality assurance of intensity-modulated radiotherapy.

This study evaluated the feasibility of utilizing a 3D-printed anthropomorphic patient-specific head phantom for patient-specific quality assurance (QA) in intensity-modulated radiotherapy (IMRT). Contoured left and right head phantoms were converted from DICOM to STL format. Fused deposition modeling (FDM) was used to construct an anthropomorphic patient-specific head phantom with a 3D printer. An established QA technique and the patient-specific head phantom were used to compare the calculated and measured doses. When the established technique was used to compare the calculated and measured doses, the gamma passing rate for γ ≤ 1 was 97.28%, while the gamma failure rate for γ > 1 was 2.72%. When the 3D-printed patient-specific head phantom was used, the gamma passing rate for γ ≤ 1 was 95.97%, and the gamma failure rate for γ > 1 was 4.03%. The 3D printed patient-specific head phantom was concluded to be highly feasible for patient-specific QA prior to complicated radiotherapy procedures such as IMRT.

Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts.

PURPOSE: The objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti. MATERIALS AND METHODS: Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-µm dimples at 10-µm intervals, and SM30 (n=16) had 5-µm dimples at 25-µm intervals in a 2 × 4 mm(2) area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences. RESULTS: The adhesion strength of epithelial cells was higher on Ti surfaces with 5-µm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins. CONCLUSION: These findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.

A study on the synthesis of polystyrene-silica nanocomposite particles by soap-free emulsion polymerization using cationic initiator in company with colloidal silica sol solution.

Nano-sized polystyrene (PS)-silica nanocomposite particles have been prepared by soap-free emulsion polymerization using a cationic initiator, 2,2'-azobis(isobutyramidine) hydrochloride (AIBA) with a colloidal silica (Ludox SM30, 7 nm diameter). The cationic initiator leads to the formation of the PS-silica nanocomposite particles by electrostatic interaction with negatively charged silica particles. Morphology, particle size distribution, reactivity and silica content of the particles were monitored on different reaction conditions such as pH, the addition time of silica sol and the amount of the silica sol. It is found that the nucleation of styrene monomer depends on the pH of water medium, the addition time of silica, the presence of silica in polymerization system. The reaction whose styrene monomer didn't react in water medium with pH 10 was progressed in the presence of silica sol to give nanocomposite particles. In the condition of constant pH 10 in the polymerization system, the increase of the amount of silica gave little influence to the changes in the particle size and particle size distribution of nanocomposite particles. The changes in the pH of medium gave much influence on the particle size and particle size distribution due to the changes in ionic interaction of silica and initiator. The silica content absorbed on the nanocomposite particles decreases with decreasing the pH values in the polymerization media.

Fabrication of a highly efficient core-mode blocker using a femtosecond laser ablation technique.

We present a method for the fabrication of a highly efficient core-mode blocker based on a laser micromachining technique. The process for the fabrication is as follows. A micron-sized crater is made by irradiation of an ultra-short pulse laser on the end face of a single-mode fiber, and then a defect that acts as a core-mode blocker is formed by splicing the cratered fiber with a normal fiber. The attenuation of the core mode was adjustable up to 25 dB according to the initial crater size and the splicing condition. An all-fiber acousto-optic tunable bandpass filter built with the core-mode blocker is also demonstrated, which exhibits a low insertion loss of 1.8 dB with non-resonance light suppression greater than 23 dB.