Development of a Serum-Free Culture Method for Endothelial Cells of the Stria Vascularis and Their Pro-Inflammatory Secretome Changes Induced by Oxidative Stress.

OBJECTIVES: Reactive oxygen species in the stria vascularis (SV) of the cochlea may be involved in the pathogenesis of sensorineural hearing loss. However, the effects of oxidative stress on SV endothelial cells (SV-ECs) remain largely unknown, and no feasible in vitro cell culture model exists for the functional study of SV-ECs. METHODS: We isolated primary SV-ECs from the SV of neonatal mice. The apoptosis-reducing effects of fibronectin in SV-ECs cultured with serum-free medium were determined using ß-galactosidase staining and flow cytometry. SV-ECs incubated in serum-free medium were treated with various H2O2 concentrations to evaluate the effects of H2O2 on their viability. The secretome of SV-ECs treated with or without H2O2 (100 µM or 500 µM) was analyzed using high-resolution mass spectrometry. The function of the SV-EC secretome was evaluated by a macrophage assay. RESULTS: We successfully isolated and characterized the SV-ECs. Treatment with H2O2 at concentrations up to 500 µM for 2 hours and further incubation with serum-free medium in plates precoated with fibronectin showed no significant effect on apoptosis. Compared to the control SV-ECs, the amount of differential proteins in the secretome of SV-ECs stimulated with 500 µM H2O2 was much higher than in those treated with 100 µM H2O2. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses suggested that the proteins differentially expressed in SV-ECs treated with 500 µM H2O2 were involved in the regulation of multiple signaling pathways and cellular processes. The secretome of H2O2-stimulated SV-ECs exhibited significant pro-inflammatory effects on macrophages. CONCLUSION: We successfully established an in vitro serum-free culture method, identified the differential proteins released by oxidative stress-induced ECs and their functions, and revealed the pro-inflammatory effects of the secretome of H2O2-stimulated SV-ECs. Therefore, SV-ECs might elicit immunoregulatory effects on bystander cells in the microenvironment of oxidative stress-induced cochlea, especially cochlear macrophages.

Smartphone Application WeChat for Clinical Follow-up of Discharged Patients with Head and Neck Tumors: A Randomized Controlled Trial.

BACKGROUND: Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. METHODS: A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up (WFU) group or telephone follow-up (TFU) group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. RESULTS: Time consumption in WFU group for each patient (23.36 ± 6.16 min) was significantly shorter than that in TFU group (42.89 ± 7.15 min) (P < 0.001); total economic cost in WFU group (RMB 90 Yuan) was much lower than that in TFU group (RMB 196 Yuan). Lost-to-follow-up rate in the WFU group was 7.02% (4/57) compared with TFU group, 9.80% (5/51), while no significance was observed (95% confidence interval [CI]: 0.176-2.740; P = 0.732). The overall satisfaction rate in WFU group was 94.34% (50/53) compared with 80.43% (37/46) in TFU group (95% CI: 0.057-0.067; P = 0.034). CONCLUSIONS: The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-IOR-15007498; http://www.chictr.org.cn/ showproj.aspx?proj=12613.

Biological characteristics of CD133(+) cells in nasopharyngeal carcinoma.

Cancer stem cells are regarded as the cause of tumour formation and recurrence in nasopharyngeal carcinoma (NPC). However, ideal surface markers for stem cells in NPC remain unidentified. In the present study, we investigated the expression of CD133, Nanog and Sox2 in the nasopharyngeal carcinoma cell line CNE2 and primarily cultured NPC cells using immunofluorescence or flow cytometry. A cell population with a CD133(+) phenotype was enriched using magnetic-activated cell sorting technology. We demonstrated that CD133(+) cells exhibited a strong potential for self-renewal, proliferation and differentiation and a greater potential for in vivo tumour formation in nude mice compared to CD133(-) cells, although the percentage of CD133(+) cells was small. However, the specific marker antigens Nanog and Sox2 were simultaneously expressed in normal cancer stem cells. Our results showed that CD133 can serve as a specific surface marker for nasopharyngeal cancer stem cells.

Removal of tracheobronchial foreign bodies via suspension laryngoscope and Hopkins telescope in infants.

OBJECTIVES: Tracheobronchial foreign body aspiration is a life-threatening accident in infants, and is still a formidable clinical emergency to both otorhinolaryngologists and anesthesiologists. In this study, we attempted to assess the safety and ease of tracheobronchial foreign body removal in infants via suspension laryngoscopy and Hopkins telescopy under general anesthesia with endotracheal intubation. METHODS: The retrospective clinical study from 2006 to 2010 included 50 infants with foreign body aspiration, of whom 35 underwent suspension laryngoscopy and Hopkins telescopy and the other 15 underwent rigid bronchoscopy. All of the procedures were under general anesthesia with endotracheal intubation. RESULTS: All of the patients underwent temporary extubation. The foreign body was successfully removed in 46 cases and was not found in the other 4 cases. The mean operation time in the rigid bronchoscopy group was 13.20+/-9.01 minutes, and that in the Hopkins telescopy group was 5.79+/-3.54 minutes. The oxygen saturation level was below 90% in 17 cases, of which 7 were in the rigid bronchoscopy group and 10 were in the Hopkins telescopy group. The vital signs, including the partial pressure of carbon dioxide in expiratory gas and the heart rate, were stable in all cases. CONCLUSIONS: Foreign body removal in infants via suspension laryngoscopy and Hopkins telescopy under general anesthesia with endotracheal intubation should be promoted, since it is relatively safe and easy for both anesthesiologists and otorhinolaryngologists to perform and has a remarkable success rate.

[Numerical simulation study on effects of ambient temperature on airflow in the nasal cavity].

OBJECTIVE: To study the aerodynamics of the normal human nasal cavity under different ambient temperatures. METHODS: Based on CT scanning, a model of a healthy adult's nasal cavity was established using computational fluid dynamics software from Fluent. Airflow in this model was simulated and calculated at ambient temperatures of 0 °C, 24 °C, and 37 °C during periodic breathing. RESULTS: Ambient temperature only had an impact on the temperature in the nasal cavity during the inspiratory phase, and the temperature distribution was not symmetrical in the inspiratory acceleration and deceleration phases. The ambient temperature significantly affected airflow speed in main nasal passages during the inspiratory process, but had little impact on flow status (proportion and streamline of airflow in different nasal passages). Temperature differences increased the irregular air movement within sinuses. The anterior nasal segment, including the area between the valve and the head of the middle turbinate, was the most effective part of the nasal airway in heating the ambient air. CONCLUSIONS: Our findings describe the effects of ambient temperature on airflow parameters in the nasal cavity within a single respiratory cycle. This data is more comprehensively and accurately to determine the relationship between nasal cavity aerodynamics and physiological functions.

[A comparative study on numerical simulation of the normal nasal airflow during periodic breathing and steady-state breathing].

OBJECTIVE: To compare the characteristics of normal nasal airflow during periodic breathing and steady-state breathing. METHODS: Fluent software was used to simulate the nasal cavity and paranasal sinus structures following CT scanning of a normal adult subject. Air flow velocity, pressure, distribution and streamlines were calculated and compared during periodic breathing and steady-state breathing. RESULTS: The same flux, the performance of nasal airflow on 15.600 s of periodic breathing and steady-state expiratory (entrance flow was 697.25 ml/s) were as follows: air flow in the common and middle meatus accounted for more than 50% and 30% of total nasal cavity flow during two respiratory status. Flow velocity and pressure of nasal cavity and each paranasal sinus were extremely similar. The flow trace during two respiratory status in the inferior and lower part of the common meatus were predominately straight in form.Flow were parabolic in the middle and superior meatus and the middle and upper parts of the common meatus. The flow trace of nasal airflow on 16.495 s of periodic breathing had wide areas vortex in nasopharynx and limen nasi, the average speed was 0.0706 m/s, while the entrance flow 7.62 ml/s stable state of the left nasal expiratory, the average speed was 0.0415 m/s, the flow trace was similar to 697.25 ml/s. CONCLUSION: The same flow, except in the junction of the respiratory cycle, the performance of normal nasal airflow during periodic breathing and steady-state breathing were similar.

Damage of nasal mucociliary movement after intensity-modulated radiation therapy of nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: Radiation usually results in paranasal sinusitis in patients with nasopharyngeal carcinoma (NPC), which influences patients' quality of life. This study aimed to determine the relationships between dose distribution in the nasal cavity and nasal mucous injury in patients with NPC treated by intensity-modulated radiation therapy (IMRT), and to find the tolerable radiation dose for the nasal mucous. METHODS: Sixty-six patients with NPC treated by IMRT between October 2006 and November 2008 were enrolled. The irradiation dose in the nasal cavity was determined by the computer with the IMRT work platform. Mucociliary transport rate (MTR) was detected by modified saccharine test before IMRT, at the end of IMRT, and at 3, 6, and 12 months after IMRT. RESULTS: The data were available for 129 nasal cavities. The cavities receiving a mean dose below or equal to 37 Gy showed substantial preservation of nasal mucous after IMRT. The MRT decreased to (62.82 ± 38.59)%, (56.78 ± 37.79)%, (64.05 ± 39.37)%, and (71.13 ± 39.55)% of pre-IMRT value at 4 time points after IMRT, with significant differences among the data (P < 0.05). In contrast, when the cavities received a mean dose higher than 37 Gy, no significant differences in MTR among the time points were observed. At 3 months after IMRT, the MTR was the lowest (38.27% of pre-RT value). CONCLUSIONS: A mean radiation dose of ≤ 37 Gy for the nasal cavity is an optimal dose to protect the nasal cavity function.

[Influence of uncinate process on aerodynamic characteristics of nasal cavity and maxillary sinus].

OBJECTIVE: This study aimed to investigate the influence of uncinate process on air flow velocity, trace, distribution, air pressure, as well as the air flow exchange of nasal cavity and paranasal sinuses. METHODS: Fluent software was used to simulate two nasal cavity and paranasal sinus structures following CT scanning, one had normal nasal cavity, the another had the nasal cavity with uncinate process removed. Air flow velocity, pressure, distribution and trace lines were calculated and compared by Navier-Stokes equation and numerically visualized between two models. RESULTS: Air flow of two models in the common and middle meatus accounted for more than 50% and 30% of total nasal cavity flow. Flow velocity of two models were maximal in the common meatus, followed by the middle meatus. The maximal velocity existed on the left nasal district between limen nasi and head of inferior turbinate. The flow traces of two models were similar. In the normal model, the air flow velocity of the district around uncinate process was almost the same in inhale and exhale. In the model with the uncinate process removed, the air flow velocity of the district around uncinate process was faster, the air flow velocity in expiratory phase was quicker. Compared with the normal nasal cavity, there was more exchange of maxillary sinus in the model with cut uncinate process. CONCLUSIONS: In the view of flow dynamics, the uncinate process effects the air flow velocity of the district around uncinate process and the exchange of maxillary sinus, the contribution of nasal flow is connected with the morphosis of the uncinate process.

[Effect of endoscopic sinus surgery on airflow of the nasal cavity and paranasal sinuses: a computational fluid dynamics study.].

OBJECTIVE: To study the airflow velocity, trace, distribution, pressure, as well as the airflow exchange between the nasal cavity and paranasal sinuses in a computer simulation of nasal cavity pre and post virtual endoscopic sinus surgery (ESS). METHODS: Computational fluid dynamics (CFD) technique was applied to construct an anatomically and proportionally accurate three-dimensional nasal model based on a healthy adult woman's nasal CT scans. A virtual ESS intervention was performed numerically on the normal nasal model using Fluent 6.1.22 software. Navier-Stokes and continuity equations were used to calculate and compare the airflow characteristics between pre and post ESS models. RESULTS: (1) After ESS flux in the common meatus decreased significantly. Flux in the middle meatus and the connected area of opened ethmoid sinus increased by 10% during stable inhalation and by 9% during exhalation. (2) Airflow velocity in the nasal sinus complex increased significantly after ESS. (3) After ESS airflow trace was significantly changed in the middle meatus. Wide-ranging vortices formed at the maxillary sinus, the connected area of ethmoid sinus and the sphenoid sinus. (4) Total nasal cavity resistance was decreased after ESS. (5) After ESS airflow exchange increased in the nasal sinuses, most markedly in the maxillary sinus. CONCLUSIONS: After ESS airflow velocity, flux and trace were altered. Airflow exchange increased in each nasal sinus, especially in the maxillary sinus.

Computational fluid dynamics simulation of airflow in the normal nasal cavity and paranasal sinuses.

BACKGROUND: This study aimed to investigate airflow velocity, trace, distribution, and air pressure, as well as the airflow exchange between the nasal cavity and paranasal sinus in a normal subject using computational fluid dynamics. METHODS: Fluent software is used to simulate nasal cavity and paranasal sinus structure after CT scanning of a normal adult subject. Airflow velocity, pressure, distribution, and trace lines were calculated by Navier-Stokes equation and numerically visualized. RESULTS: Airflow in the common and middle meatus accounted for >50 and 30% of total nasal cavity flow. Flow velocity was maximal in the common meatus, followed by the middle meatus. Flow velocity and flux in each paranasal sinus was extremely low. The flow trace in the inferior and lower part of the common meatus was predominately straight in form. Flow was parabolic in the middle and superior meatus and the middle and upper parts of the common meatus. Air pressure was high at the front end of the inferior and middle turbinate and the uncinate process. There was little pressure difference/flow exchange between inner and outer aspects of the paranasal sinus. CONCLUSION: The major airflow forms are straight (lower common and inferior meatus) and parabolic (middle and upper common meatus and middle superior). Flow force is strongest at the front end of the inferior and middle turbinate and uncinate process. There is very little exchange between the paranasal sinus and the nasal cavity during stable airflow.