Cytocompatibility of a novel nasal packing material made of polyethylene glycol diacrylate composite hydrogel / 中国组织工程研究

BACKGROUND: Previous studies have shown that the complex of polyethylene glycol diacrylate and chitosan is biodegradable, has the anti-inflammation effect and can promote wound healing, with good biocompatibility.However, the composite material is brittle, and thus, it is necessary to develop a mechanical support material due to the anatomy of the nasal cavity.OBJECTIVE: To study the cytocompatibility of a novel degradable absorbable nasal packing material made of polyethylene glycol diacrylate composite hydrogel.METHODS: In our experiment, the composite hydrogel was formed by the combination of different ratios of polyethyleneglycol diacrylate, chitosan and polyvinyl alcohol using photo-crosslinking method. According to the international standard of medical devices, we used direct and indirect international standard experimental methods to evaluate the cytotoxicity of the materials. (1) Direct contact method: the polyethylene glycol acrylate composite hydrogel and mouse fibroblasts L929 were co-cultured for 24 hours to observe the morphological changes of cells. (2) Indirect extraction: mouse fibroblasts L929 were cultured in polyethylene glycol diacrylate composite hydrogel extracts (100, 50 μL) and RPMI1640 medium (100 μL), respectively, for 3 days to observe the proliferation and cytotoxicity by cell counting kit-8 assay.RESULTS AND CONCLUSION: (1) Direct contact method: the cells around the material formed a flat structure with fusiform or stellated protrudes. The material was confirmed to have good biocompatibility depending upon the presence of adherent cell growth, full and strong refraction, and the overall growth trend. (2) Indirect extraction method: with the increase of time, the number of cells in the hydrogel extract group increased, the relative proliferation rate of cells increased gradually, and the cytotoxicity was 0 to 1. To conclude, these experimental findings indicate that the polyethylene glycol acrylate composite hydrogel material has good cytocompatibility.

CT and MR findings of the respiratory epithelial adenomatoid hamartoma in the nasal olfactory clefts / 中华放射学杂志

Objective To study the CT and MR characteristic features of the respiratory epithelial adenomatoid hamartoma of olfactory clefts. Methods (1)The CT and MRI findings of 29 patients with histologically proved respiratory epithelial adenomatoid hamartoma in the olfactory clefts were retrospectively reviewed.All patients underwent CT and 8 of them underwent MRI. Location, CT and MRI features, and associated findings of the disease were reviewed;(2)The CT findings, olfactory clefts width, total nasal distance, and the ratio of OC to the total nasal distance of the case patients (29 cases) and the control patients (33 patients with sinusitis) were compared to investigate the correlation of the olfactory clefts distance and the incidence of respiratory epithelial adenomatoid hamartoma in olfactory clefts. Results All patients were associated with sinusitis, and 23 had sinonasal polyps, 1 had papilloma. On nonenhanced CT, the OC lesions with the OC widening were isodense to gray matter in all cases, and the lesions caused the adjacent bony expansion and absorption rather than erosion; 15 cases were bilateral diseases and 14 were unilateral;The olfactory clefts width of the case patients and the control patients were (1.03±0.24) cm, (0.71± 0.17) cm, respectively. There was statistically significant difference (t=4.963, P0.05) for the total nasal distance, and was significant difference(t=6.029,P<0.01)in the ratio of OC to the total nasal distance between the two groups. On T1WI, the disease appeared isointense in 6 patients and slightly hypointense in 2 patients compared with gray matter. On T2WI, the lesions revealed heterogeneous isointense in all patients. Regular cribriform pattern was found on MR T2WI and enhanced TlWI. Conclusions The unilateral or bilateral olfactory cleft opacification in chronic sinusitis patients with or without sinonasal polyposis, with involved OC widening and the adjacent bony walls compressed and remodeled may highly suggests the presence of REAH in the OC. The lesions showed inhomogeneous isointense signal on T2WI images, regular cribriform pattern enhancement are typical imaging feature of this entity.

Study on the correlation between the ostia diameter changes and airflow characteristics in maxillary sinus / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the maxillary sinus flow field, temperature field and the maxillary sinus ostium size, and to provide a reference for endoscopic surgery according to the maxillary sinus scope.</p><p><b>METHODS</b>One case of adult female CT image data was obtained, and used to build a three-dimensional model of nasal cavity and maxillary sinus. Computational fluid dynamics method was used to study the airflow and temperature of the maxillary sinus, as well as the physiological function of the maxillary sinus. Simulation surgery by means of different maxillary sinus diameters (normal, 8 mm, 10 mm, 12 mm and 15 mm) was used to describe the maxillary sinus airflow and temperature change.</p><p><b>RESULTS</b>It was found that by numerical simulation the airflow of maxillary sinus and nasal cavity showed lower speed (average speed 0.062 m/s) than that in the middle nasal meatus (average speed of 3.260 m/s), and the average temperature in the normal maxillary sinus was 34°C, which was higher than that in the middle nasal meatus (temperature 28.7°C). With the increase of the diameter of the maxillary sinus, the air temperature change was not obvious.</p><p><b>CONCLUSIONS</b>The physiological function of the maxillary sinus can be studied through the numerical simulation. With the increase of the ostia diameter of maxillary sinus, the sinus temperature and ventilation is not affected. It provides a reference for quantification of clinical endoscopic maxillary sinus surgery.</p>

Pharyngeal aerodynamics characteristics in obstructive sleep apnea hypopnea syndrome patients / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo compare the differences of aerodynamic characteristics of pharyngeal cavity between normal subjects and OSAHS patients, and to study the nasal obstruction in the pathogenesis of the OSAHS.METHODSA total of 60 normal subjects and 60 OSAHS patients were enrolled in this study. Numerical simulation was performed to calculate the airflow dynamic indexes of three sections of pharyngeal cavity. Correlation analysis of the nasal resistance and negative pressure were studied.RESULTSThe average pharyngeal negative pressure and airflow velocity in OSAHS patients were significantly increased than that in normal subjects. The total nasal airway resistance significantly correlated with the average negative pressure of pharyngeal cavity. CONCLUSIONAirflow dynamic indexes of OSAHS patients had significant different pharyngeal aerodynamic characteristics from normal subjects. The increased average negative pressure in pharynx might contribute to the severity of pharyngeal collapse for OSAHS patients. Higher total nasal resistance might play a role in the pathophysiological mechanisms of OSAHS.

Effects of nasal cavity ventilation expansion techniques on airlfow patterns of the upper airway / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo compare the aerodynamic differences before and after nasal cavity ventilation expansion techniques in patients with OSAHS. METHODSA total of 30 adult patients with OSAHS were included in this study. Pre-operative upper airway CT of each subject was acquired. Each subject underwent surgery. Postoperative upper airway CT was obtained at least 3 months later. By means of CFD simulation method, numerical simulation was performed to calculate the airflow dynamic indexes of the upper airway. The pre-and post-operative aerodynamic characteristics were compared. RESULTSAfter operation, post-operative negative pressure nephogram of the nasal cavity indicated more smooth variation of pressure gradient, post-operative velocity nephogram of nasal cavity indicated slower airflow velocity. Proper values of flow field indicated the volume of nasal cavity increased significantly (t=4.025,P<0.01), the total nasal airway resistance decreased significantly (t=-2.065,P<0.01). The total negative pressure of the upper airway decreased significantly (t=-2.659,P<0.01) after operation. However, the proper values of flow field increased in 5 patients. CONCLUSIONNasal cavity ventilation expansion effectively increase the volumes of nasal cavity, improve the nasal ventilation, and reduce the air flow velocity of both nasal cavity and pharynx in OSAHS patients, those reduce the pharyngeal negative pressure and the pharyngeal collapse. However, for patients with its narrowest segment at the velopharyngeal level, operation cannot do anything or even aggravate the pharyngeal collapse. Operation should be performed individually.

Characteristics of nasal sinus lfow in patients with chronic sinusitis before and after endoscopic sinus surgery / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo evaluate the curative effect of endoscopic sinus surgery from the viewpoint of biomechanics analysis.METHODSWe select one case undergoing nasal endoscopic surgery for chronic sinusitis patients, after half year follow-up and collect preoperative and postoperative spiral CT data to build a numerical model of nasal cavity and paranasal sinuses with computer numerical simulation (CFD) research methods, to explore nasal airflow distribution and flow field characteristics of value changes before and after the operation. Patients undergo subjective assessments: nasal obstruction of VAS score, olfactory VAS score, SNOT-20, objective assessment: Lund Kennedy score, Lund Mackay score, saccharin test time and acquisition clinical efficacy data to verify the credibility of the analysis method is feasible and the results. RESULTSThe nasal resistance after endoscopic sinus surgery in nasal cavity and paranasal sinuses numerical simulation decreased, middle meatus of nose and nasal air flow velocity decreased, the pressure change slightly;nasal threshold region, middle turbinate head end section in maxillary sinus ostium section, after nearly sieve horizontal cross-section average velocity decreased, nasal airflow for the mucosa of the shear stress reduced. The volume of the nasal cavity and the area of the mucosa was increased, the volume ratio was decreased, the subjective and subjective assessment of the patients was improved, and the objective assessment was lighten.CONCLUSIONAerodynamic rules are presented through the calculation of numerical simulation of fluid mechanics which is invisible before. Better understanding of changes in the nasal airflow distribution and the changes of flow field characteristics can be useful to establish nasal endoscopic surgery in numerical analysis of offshore platform,which provides a new research tool for the understanding of the pathophysiology of chronic sinusitis by endoscopic sinus surgery.

Analysis of epidermal growth factor signaling in nasal mucosa epithelial cell proliferation involved in chronic rhinosinusitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Aberrant epithelial repair has been observed in chronic rhinosinusitis (CRS) patients; however, the mechanism of epithelial cell repair regulation is unclear. Epidermal growth factor (EGF) plays an important role in regulating epithelial cell repair in lower airway and may be a critical factor in the remodeling processes of CRS. The objective of our research is to evaluate the differences between CRS and normal subjects and between chronic rhinosinusitis without nasal polys (CRSsNP) and chronic rhinosinusitis with nasal polys (CRSwNP) in the regulation of EGF pathways and the regulating proliferative position of classic Ras/Raf/MEK/ERK pathways.</p><p><b>METHODS</b>We evaluated the proliferation rates of ethmoidal mucosal cells before and after stimulation with EGF, epidermal growth factor receptor (EGFR) kinase inhibitor AG1478, and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 using MTT assays. We also analyzed the sinonasal epithelial cells collected from control subjects and patients with CRS subtypes CRSsNP and CRSwNP for the expression of ERK1/2, phosphorylated ERK1/2, P21, P15, and P27 using western blotting analyses.</p><p><b>RESULTS</b>The proliferation rates of sinonasal epithelial cells before and after EGF stimulation were lower in CRS patients than in the controls. AG1478 or PD98059 inhibitor treatment of control epithelial cells did not result in a significant difference in proliferation. Although, AG1478 and PD98059 inhibited the proliferation of CRS cells, the degree of proliferation inhibition was markedly different in CRSsNP. AG1478 suppressed the proliferation of CRSwNP epithelial cells, whereas PD98059 had no effect. The ratio of ERK1/2 phosphorylation in CRS cells was lower than that of the control cells. Cyclin-dependent kinase inhibitors were highly expressed in CRS cells compared with that of control cells. ERK1/2 and P27 showed differential expression in CRSsNP and CRSwNP.</p><p><b>CONCLUSIONS</b>Differences existed in EGF pathways in CRS patients and normal subjects as well as in CRSsNP and CRSwNP. Classical Ras/Raf/MEK/ERK pathway may assume absolute superiority in control cells. Ras/Raf/MEK/ERK classical pathway and other pathways might be active at the same time to stimulate epithelial cell proliferation in CRSsNP. The function of Ras/Raf/MEK/ERK classical pathway was weaker in CRSwNP than in CRSsNP and when the classical pathway was blocked in CRSwNP, some other pathway could have completely compensated the proliferation induced by the Ras/Raf/MEK/ERK pathway.</p>

Analysis of prognostic factors in endoscopic surgery for juvenile nasopharyngeal angiofibroma / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#Analyzing the prognostic factors in endoscopic surgery of juvenile nasopharyngeal angiofibromas (JNA).@*METHOD@#Forty-seven records of JNA, treated with the endoscopic, from 2002 to 2008 were reviewed retrospectively. Previous surgery in other hospitals, sites involved, whether selective embolization was performed before surgery, feeding vessels, operative techniques and follow-up results were recorded. Evaluated factors include previous surgery for resection of JNA, vascular supply from carotid artery, surgery after selective embolization, involvement of cavernous bone in the root of pterygoid process, greater wing of sphenoid bone, interpterygoid fossa, infratemporal fossa and orbit. Chi-square test was used.@*RESULT@#Operations were done under general anesthesia. The follow-up time was 12 to 87 month (median 35 month). During follow up, six patients presented recurrent lesions. Chi-square test showed that deep invasion of the cavernous bone in the root of pterygoid process was related to recurrence (P<0.05). There was no statistically significant difference between other factors and recurrence. Imaging examination showed that recurrent tumor was around the root of pterygoid process.@*CONCLUSION@#Deep invasion of the cavernous bone in the root of pterygoid process which was related to recurrence deserve close attention before and after endoscopic surgery.

Bilateral effects of the pre- and postoperative septoplasty evaluated objectively with acoustic rhinometry and rhinomanometry / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To evaluate effects of septoplasty on bilateral nasal cavities with acoustic rhinometry and rhinomanometry objectively.@*METHOD@#Twenty-two patients who underwent septoplasty were examined with rhinomanometry and acoustic rhinometry before and 6 to 12 months after surgery. Of the 22 patients, 1 patient whose rhinomanometry and acoustic rhinometry datum were not available for the bilateral nasal obstruction, 3 patients with bilateral turbinectomy and 2 patients with unilateral turbinectomy wide nasal cavities were excluded. Finally, 18 narrow side nasal cavities and 16 wide side nasal cavities were analyzed.@*RESULT@#Rhinomanometry: nasal resistance on the deviation side decreased significantly (P 0.05). Acoustic Rhinometry: the predecongestion nasal minimal cross-sectional area (NMCA) and 0-5 cm NCV on the deviation side increased significantly due to the operation (P 0.05). Only slight median increases were noted in the bilateral assessment postoperatively in NCV (P > 0.05) before and (P < 0.05) after decongestion.@*CONCLUSION@#The nasal patency on the deviation side is undoubtedly increased after septoplasty, and the airway on the wide side is not worsened after the operation.

Clinical use of nasal obstruction,CT and acoustic rhinometry in diagnosing the remodeling of nasal mucosa in chronic rhinosinusitis / 中国耳鼻咽喉头颈外科

OBJECTIVE To investigate the correlation between nasal obstruction score, Lund-Mackay score,congestion index and tissue remodeling degree of nasal mucosa in patients with chronic rhinosinusitis(CRS) and to study the role of diagnosing remodeling.METHODS Forty-three patients with CRS who underwent endoscopic surgery were studied.Congestion index of nasal mucosa was obtained by acoustic rhinometry.Nasal obstruction score was obtained by visual analogue scale.CT score was obtained by Lund-Mackay.The mucosa specimen of uncinate process from nasal cavity of the patients was used to evaluate the fibrosis degree.Statistical analysis was performed using SPSS11.5.RESULTS Nasal obstruction and Lund-Mackay score had no correlation with fibrosis degree of mucosa(r=0.77,P=0.40),whereas congestion index of nasal mucosa had a negative correlation with fibrosis degree of mucosa(r=-0.348, P=0.022).CONCLUSION Nasal congestion index can reflect the degree of remodeling in submucosal tissue.Nasal congestion index with obstruction symptoms and CT scan can be used to guide the CRS treatment strategies.