Advances in Clinical Application of Numerical Study of Ear and Upper Airway / 医用生物力学

Ear and upper airway are portal organs of human body. Because of their fine and narrow structure, the non-invasive research and the effect of clinical diagnosis and treatment in traditional medicine are always unsatisfactory. With the development of computer technology, numerical simulation has become an effective means of auxiliary research. Numerical simulation can reproduce or evaluate the diagnosis and treatment of ear and upper airway diseases, and it is a powerful means to promote the development of basic medicine and technology of clinical diagnosis and treatment. The application of numerical simulation in relationship between the structure and function of ear and upper airway, the influence of diseases on function, the evaluation of clinical diagnosis and treatment technology， as well as the design of related medical devices were reviewed. The clinical application of numerical research in ear and upper airway was prospected, so as to provide references for the future clinical diagnosis and treatment of ear and upper airway.

Analysis of prognostic influencing factors of acute hearing loss after posterior circulation ischemic stroke / 中国医师进修杂志

Objective@#To assess the prognostic influencing factors of acute hearing loss after posterior circulation ischemic stroke.@*Methods@#The clinical data of 50 patients with acute hearing loss caused by posterior circulation ischemic stroke in Dalian Central Hospital Affiliated to Dalian Medical University from January 2016 to December 2018 were retrospectively analyzed. Patients were followed up for 2 to 37 months, with an average of 30 months. At the last follow-up, hearing recovery was assessed. Patients with complete and partial improvement of hearing were classified as hearing improvement group, and patients with no improvement of hearing were classified as hearing without improvement group.@*Results@#There was 32 cases in hearing improvement group and 18 cases in hearing without improvement group. There were no statistical differences in gender composition, age, smoking, diabetes mellitus, hypertension, hyperlipidemia, history of stroke/temporary ischemic attack (TIA), onset to treatment time, hearing loss degree, hearing and vertigo between 2 groups (P>0.05). The proportion of ≥ 2 risk factors in hearing without improvement group was significantly higher than that in hearing improvement group: 17/18 vs. 65.6% (21/32), and there was statistical difference (P<0.05).@*Conclusions@#Acute hearing loss caused by posterior circulation ischemic stroke has a good prognosis, but the patients with multiple risk factors for stroke have poor hearing recovery.

Effect of anatomical changes of frontal recess and frontal sinus on airflow after nasalisation by image reconstruction and numerical simulation / 中华耳鼻咽喉头颈外科杂志

Objective@#To describe the influence of post-operative anatomical structure changes on nasal airflow characteristics by 3D reconstruction and numerical simulation in real cases after nasalisation with Draf Ⅲ so as to explore the correlation between the changes of anatomical structure and subjective symptoms as well as airflow characteristics.@*Methods@#Ten patients underwent nasalization with Draf Ⅲ in Department of Rhinology in Beijing Tongren Hospital from 2006 to 2018 were selected retrospectively. Postoperative follow-up of all patients was more than 1 year. All patients had no abnormalities in their paranasal sinus CT scans and Lund-Kennedy scores were 0 except scar. VAS scores including nasal obstruction, stimulation in frontal sinus, and headache were collected at the same period. The control model was a normal person. Numerical simulation was used for calculating airflow characteristics in deep inspiratory period of both models. Independent sample Mann-Whitney U test and Spearman correlation test were used by software SPSS 22.0.@*Results@#The airflow pressure in frontal sinus ostium was (7.21±1.39)×104 Pa (Mean±SD), which was lower than that in normal subjects (8.99×104 Pa) under deep inspiratory simulation. But, the velocities in frontal sinus ostium and frontal sinus were (40.10±2.46) m/s and (28.19±1.73) m/s respectively, which were higher than those in normal one (2.70 m/s, 0.73 m/s). The airflow patterns of the two models were basically similar. There was no significant difference in the opening size and volume of frontal sinus between different groups after grouped by three symptoms respectively. No correlation could be found between the opening size and volume of the frontal sinus with the appearance and severity of three subjective symptoms.@*Conclusions@#The airflow pattern and distribution after nasalisation with Draf Ⅲ are like those of normal person. There is no correlation between the changes of anatomy in frontal recess and frontal sinus and nasal airflow characteristics as well as subjective symptoms.

The mechanism of sensing postural changes in human ears by numerical simulation / 医用生物力学

Objective To study the general mechanical behavior pattern of sensing angular velocity by 3 pairs of human semicircular canals.Methods Sinusoidal head rotation of a healthy subject was simulated by finite element method to analyze the dynamic responses in the above 3 pairs of canals in the left and right inner ear.Results Compared with the complicated node displacement distribution,the volumetric strain distribution of cupula was regular.Specifically,each pair of cupulae expanded or contracted within the same amplitude with the same response frequency to the angular velocity.The ratio of absolute volumetric strain among the horizontal semicircular canal cupula (HC cupula),the anterior semicircular canal cupula (AC cupula),and the posterior semicircular canal cupula (PC cupula),was approximately 1.00∶0.80 ∶ 1.72,which kept constant.In addition,the volumetric strain of HC cupula was in phase with that of AC cupula,but showing 14.4° out of phase with the angular velocity,and 180° out of phase with that of PC cupula.Conclusions The volumetric strain of cupula can preferably characterize the directional coding function of semicircular canal,and the amplitude,frequency and phase of the cupular volumetric strain can encode those of the stimulated angular velocity,respectively.These results will lay the foundation for establishing quantitative relationship of vestibulo-ocular reflex,and provide theoretical references for quantitative assessment for vestibular function by nystagmus examination.

Nasal endoscope surgery of acinic cell carcinoma of salivary gland on nasal septum: a case report / 临床耳鼻咽喉头颈外科杂志

A 67-year-old male patient was admitted because of "the right side nasal obstruction repeatedly for 4 years". He got nasal obstruction 4 years ago, especially for the right side nasal cavity, sometimes got blood in his nasal discharge, then the symptom relieved after accepting treatment in local hospital. During the 4 years, the symptom repeatedly occurrence. Three days before hospitalization, the CT examination indicated abnormal things in his nasal cavity and the bone of his nasal sinus had been destroyed. Some abnormal organism were sent to pathological examination, and the report indicated it is acinic cell carcinoma of salivary gland. During the nasal endoscope surgery, a red goiter was found in his nose with its surface crude and brittle. Then we cut the goiter by nasal endoscope, during the operation we find the bottom of the goiter is on the nasal septum. Two weeks after the operation, the patient received the radiation therapy. One year after the operation he doesn't get the abnormal symptom and the nasal MRI not found recidivation.

Numerical simulation of intranasal airlfow ifeld / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo explore the basic characters of the airflow-field in Chinese people's nasal cavity by computational fluid dynamics.METHODSThe three-dimensional, finite-element mesh were developed from Spiral CT imaging scans of nose of the 40 healthy Chinese people. Given the following spatial boundaries of the flow field: no-slip condition was imposed at the surface of the nasal airway walls; a standard atmosphere pressure condition was established at the inlet; a velocity vector was specified at the outlet (nasopharynx), which was obtained under the condition of aspiratory flow rate (12 L/min), the full Navier-Stokes and continuity equations were solved to obtain the airflow pattern.RESULTS1. The airflow passed mainly through left or right side of the nasal airway in the whole 40 cases (left 33, right 7),and the volume of air through the main-side is (320±28) ml while non-main-side (180±45) ml. 2. Airflow velocity: airflow of anterior nostrils, internal nostrils, the middle and inferior parts of the total meatus in the main-side were (5.01±2.12) m/s, (7.00±1.75) m/s, (5.08±1.55) m/s, (4.12±1.40) m/s respectively, and those in non-main-side were (2.01±0.94) m/s, (2.40±0.34) m/s, (1.99±1.0) m/s, (2.01±0.65) m/s respectively, which differences between the both sides were of statistical significance (allP0.05); 3. The airflow form appeared to be linear in the middle and inferior parts of the nasal cavity. 4. Velocity in maxillary sinus cavity was almost 0 m/s.CONCLUSIONThe airflow passes mainly through the middle and inferior parts of the meatus with higher velocity in laminar form and airflow of middle meatus, inferior meatus and olfactory cleft are low and the velocity were slow. Besides, airflow in maxillary sinus cavity diffuses free mainly.

Establishment of Finite Element Model and Analysis of Airflow Characteristics in Patients with Nasal Structural Abnormalities / 中国医科大学学报

Objective To analyze the airflow characteristics and investigate the relationship of the structure and the function of nasal cavity by the three?dimensional reconstruction of nasal airway of patients with structural abnormalities(nasal septum deviation)and healthy people and the estab?lishment of finite element model by computer. Methods On the basis of CT imaging of the nasal cavity in patients with structural abnormalities(na?sal septum deviation,n=20)and healthy people(n=20),three?dimensional reconstruction of nasal airway was conducted by resurfacing finite ele?ment subdivision to simulate the characteristics of airflow in nasal cavity. Results The airflow mainly went through the commodious side of the nose in patients with nasal septum deviation and the maximum fluence appeared in the middle part of meatus nasi communis. The airway pressure de?creased most significantly in the most flank?curvature part of nasal septum deviation,accounting approximately 79.65%of the total pressure. In healthy people,the bilateral airflow was affected by nasal cycle and was mainly characterized by one nasal cavity,and the maximum fluence was ob?served in the middle and the inferior part of meatus nasi communis. The airway pressure decreased most significantly in limen nasi,accounting ap?proximately 58.78%of the total pressure. Conclusion Numerical modeling of nasal cavity can be used to analyze the relationship between the nasal structural abnormalities and the airflow characteristics,which is a scientific method to analyze the association of nasal structure and function with dis?ease and can be used for pre?and post?operative individual evaluation of operative therapeutic regimen targeting at optimizing airway and altering air?flow distribution.

Numerical research on the deposition of suspended particulate matter in respiratory tract / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo study the deposition of suspended particles in the respiratory tract during human breathing.METHODSBased on CT data, three dimensional finite element model of an anatomically accurate respiratory tract, including the nasal cavity, oral cavity, pharynx, larynx, trachea and parts of tracheobronchial tree, is established. Numerical analysis for the deposition of suspended particles in the respiratory tract was conducted. RESULTSThe velocity and pressure distributions of airflow in the respiratory tract were obtained, as well as the particles path and their deposition law.CONCLUSION Respiratory tract plays an important role in filtering suspended particles in the air during breathing. The main deposition sites of the particles were at the front of the inferior turbinate and the posterior pharyngeal wall.

Foxp3(+)Treg cells mediate immune protection of Humulus pollen allergy DNA vaccine pcDNA3.1-Hum in asthmatic mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a humulus pollen allergy DNA vaccine pcDNA3.1-Hum and investigate its effect for immune protection mediated by Foxp3(+)Treg cells in asthmatic mice.</p><p><b>METHODS</b>The target humulus gene obtained from pTripIEx2-Hum plasmid by double enzyme digestion was inserted sequentially into pcDNA3.1(-) vector to generate the recombinant plasmid pcDNA3.1-Hum, which was validated by sequencing. The pcDNA3.1-Hum plasmid was transfected into COS-7 cells and the expression of the ectopic protein was analyzed using Western blotting. Co-cultured dendritic cells and CD4(+)CD25(-) T cells were stimulated with the expressed protein to test its efficacy in inducing Foxp3(+)Treg cells. The levels of humulus-specific IgE and IgG2a were assayed to evaluate the allergenicity and immunogenicity of pcDNA3.1-Hum in mice. The immunoprotective effect of pcDNA3.1-Hum was assessed in a mouse model of humulus-specific asthma.</p><p><b>RESULTS</b>The constructed pcDNA3.1-Hum plasmid was validated by sequencing and Western blotting, and the expressed protein was shown to induce Foxp3(+)Treg cells in the co-culture. In normal mice, pcDNA3.1-Hum induced a significant increase of humulus-specific IgG2a but had no effect on IgE. In the asthmatic mice, pcDNA3.1-Hum significantly decreased inflammatory cell counts and eosinophil percentages in the BALF, ameliorated lung inflammation, and lowered AHR and IL-4 levels; immunization of the mice with pcDNA3.1-Hum reversed humulus-induced reduction of serum IFN-γ and prevented the humulus-triggered reduction of Foxp3(+)Treg cell percentage in the spleen.</p><p><b>CONCLUSION</b>We have successfully constructed a highly immunogenic pcDNA3.1-Hum DNA vaccine that can mediate immune protection by inducing Foxp3(+)Treg cells.</p>

Significance and expression of VEGF and its receptor in nasal inverted papillomas and the correlation with malignant phenotype / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To determine the expression of vascular endothelial growth factor (VEGF) and their receptor in nasal inverted papillomas (NIP) and to clarify the function of VEGF in the occurrence of NIPs and the correlation with malignant phenotype.@*METHOD@#VEGF and its receptor (flk-1), expression were examined by immunohistochemistry using LSAB method in sections of NIP from 48 patients and squamous carcinoma from 8 patients.@*RESULT@#All the epithelium together with the adjacent vascular and stroma,expressed increased positive staining of VEGF and flk-1 with the degree of atypical hyperplasia in epithelium. The VEGF/flk-1 expression in epithelium was significantly stronger in severe atypical hyperplasia than that in mild atypical hyperplasia, and same in mild atypical hyperplasia than in NIPs (P<0.01).@*CONCLUSION@#VEGF/flk-1 participate in the growth of NIPs. The enhanced VEGF/flk-1 in the epithelium may be identified as one of the parameters in judging malignant transformation of NIPs.

Immunological characteristics of the recombinant major pollen allergen pTSX2 of Humulus scandens / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify the immunological characteristics of the recombinant major pollen allergen pTSX2 of Humulus scandens and evaluate its safety in immunotherapy of allergic asthma in mice.</p><p><b>METHODS</b>Western blotting was used to characterize the immunological properties of pTSX2, and its immunogenicity in normal mice was evaluated by detecting sIgG and sIgE levels. The mouse models of allergic asthma were immunized with pTSX2 and examined for sIgE and sIgG levels, total cells and eosinophils percentage in BALF, interleukin-4 (IL-4) and interferon-γ (IFN-γ) levels in BALF and spleen homogenate, and changes in lung pathologies.</p><p><b>RESULTS</b>Western blotting showed that pTSX2 reacted with the majority (about 70%) of sera from patients allergic to Humulus pollen. In normal mice, pTSX2 mainly induced the production of sIgG. In mouse models of allergic asthma, intervention with pTSX2 caused a significant reduction of sIgE and an increase of sIgG (P<0.05), significantly decreased the total cells and eosinophils in BALF (P<0.05), obviously lowered IL-4 but increased IFN-γ in BALF and spleen homogenate (P<0.05), and diminished inflammatory cell infiltration and percentage of eosinophils in the lung tissues.</p><p><b>CONCLUSIONS</b>pTSX2 shows a definite therapeutic effect and safety in the treatment of allergic asthma in mice possibly by inhibiting sIgE and inducing sIgG production, suppressing airway allergic inflammation and regulating the balance between Thl and Th2.</p>

Bioinformatical analysis of the specific allergen pTSX1 cDNA clone of Humulus pollen in allergic asthma / 西安交通大学学报(医学版)

Objective To make a bioinformatical analysis of the specific allergen pTSX1 cDNA clone obtained from Humulus pollen in allergic asthma by immunological screening and gene cloning. Methods Bioinformatical approaches, including sequence analysis, sequence alignment, genetic makeup, protein structure and function prediction, were used. Results The analysis of the specific allergen pTSX1 cDNA showed that the gene had no reading frame and coded a protein with 204 amine acids. The analysis of amine acids sequence coded by the pTSX1 cDNA showed that the protein identity of this gene product might be one of ribosomal proteins. Conclusion The pTSX1 cDNA cloned from Humulus pollen in allergic asthma is a new gene, and the protein coded by pTSX1 gene may be one of ribosomal proteins.

Construction of humulus scandens pollen major allergen pcDNA3.1-LC2 DNA vaccine and study of its immunogenicity in mice / 西安交通大学学报(医学版)

Objective To construct humulus scandens pollen major allergen DNA vaccine pcDNA-LC2 and evaluate its immunogenicity. Methods Humulus scandens pollen allergen gene was digested from recombinant plasmid pTripIEx2-LC2 by EcoRⅠ and HindⅢ of restriction endonuclease, and then inserted into expression vector pcDNA3.1(-). A large amount of endotoxin pcDNA3.1-LC2 purified plasmid was extracted after successful construction, and animal experiment was carried out to study its immunocompetence. Results Sequencing results showed that 672bp in the coding sequence of frames of recombinant pcDNA3.1-LC2 was in line with the original base line, without deletion or mutation. pcDNA3.1-LC2 of pollen allergen humulus scandens allergen vaccinated BALB/c mice. Double immunodiffusion test showed that pcDNA3.1-LC2 could be expressed and produce antibodies in mice. Conclusion Humulus scandens grass pollen major allergen DNA vaccine pcDNA3.1-LC2 has been successfully constructed. It can be expressed in mice, produces humulus scandens grass pollen allergen specific antibody and has a good immunogenicity.

Survey on Control Status and Knowledge Level about Disease in Asthmatic Patients in Region Level Cities of Shaanxi Province / 中国呼吸与危重监护杂志

Objective To evaluate the control status and knowledge level about disease in asthmatic patients in region level cities of Shaanxi province for effect appraisal of patient education.Methods Eight hospitals were selected from six region level cities, where questionnaire survey was completed in out-patients with asthma (≥ 14 years old).Results A total of 523 patients completed the questionnaire with a ratio of male to female of 1: 1.14,and an average age of (44.3±15.5) years old.The percentage of controlled, partly controlled and uncontrolled by self-evaluation was respectively 26.4%, 52.4% and 11.1%.48% insisted on using inhaled corticosteroids (ICS).The average score was 17.88±4.43 by asthma control test (ACT).The first three medicines used daily were ICS (26.6%), sustained-release theophyline (25.2%) and combination ICS/long-acting β2-agonists (21.8%).12.6% had no medicine and 5.2% used non-orthodox medicines.68.6% patients had omen before exacerbation, and those were sneezing, chest distress and cough.73.6% knew asthma is a disease of airway inilammatian,and 33.3% selected ICS as the leader medicine.Only 32.1% attended the lecture about asthma in hospitals and 85.0% longed for such education.Conclusions The control status and knowledge level about disease in asthmatic patients in cities still need to be improved in Shaanxi province, and too much work need to be done in order to realize the total control in all patients.

Internal boundary parameters identification of human middle ear with neural network / 医用生物力学

Objective To study the method of internal boundary parameters identification of middle ear.Method The numerical model is created using CT technology.Based on Matlab tools,the neural network for identifying internal boundary is proposed.Result The uniform pressure of 105 dB is applied at the outside of the tympanic membrane,and the harmonic analysis is calculated on the model to take the training samples.The internal condition parameters are identified using the good neural network.Conclusions The investiga-tion shows that the inverse method reveals a fast convergence and a high degree of accuracy.

Acoustic rhinometry and acoustic pharyngometry in the modeling of human upper respiratory tract / 生物医学工程学杂志

Acoustic rhinometry and acoustic pharyngometry (AR/P) can quantify the upper airway condition of air draft by drawing a graph plotting the nasal cavity and pharyngeal cavity cross-sectional area. Based on CT medical images of volunteers, a 3-dimensional finite element model of upper respiratory tract was reconstructed by using the method of surface rendering. The veracity of the model was valued by comparison of the relevant areas between the model and the AR/P graph; and an AR/P was used to help improve and enrich the model. The combination of AR/ P and CT is useful in studying the medicine problem related to the anatomical structure of upper respiratory tract.

Effect of removing turbinate on the airflow distribution in nasal cavity / 生物医学工程学杂志

The effect of variation of nasal structure on airflow distribution was investigated. Based on the CT images of the nose of a healthy female, a three-dimensional nasal model was developed. Two new nasal models were produced by removing part of inferior turbinate and part of middle turbinate in the left side of the original model. The numerical simulation and analysis for airflow field in the three nasal models was conducted by the finite element method. The simulation results from new models were compared with those from the original model. The airflow rate changed in the two sides of new nasal models. The airflow distribution and the pressure grades varied in the side of nasal model where part of inferior turbinate or part of middle turbinate was removed. The variation of nasal cavity structure will result in airflow redistribution in nasal cavity. The effect of removing turbinate on the airflow distribution in nasal cavity was described quantitatively.

Cloning and screening of cDNA of Psilgramma menephorn allergen / 药物分析学报

Objective To construct a cDNA expression library of Psilgramma menephorn to screen its major allergen so as to provide the basis for producing recombinant allergen vaccine of Psilgramma menephorn. Methods Total RNA was extracted from the whole body of Psilgramma menephorn with Trizol and mRNA was purified with Oligo (dT) Spin-Column. And dscDNA was synthesized through reverse transcription. After blunting, the cDNA fragments were ligated with EcoRⅠ adapters. Then the cDNAs were digested by XhoⅠ, and the fragments less than 400 bp were removed by using GHROMA SPIN-400 column. The remaining fragments longer than 400 bp were ligated with Uni-ZAP XR vector. The recombinants were packaged in vitro and a small portion of the packaged phage was used to infect E.coli XL1-Blue MRF′ for titration. The recombinants were examined by color selection. The size of cDNA inserts and the diversity of library were analyzed by PCR. The library was screened using SPT positive sera from patients with Psilgramma menephorn allergy repeatedly. Results The cDNA expression library consisting of a 5×105 recombinant bacteriophages was constructed with the recombinant ratio of 67%. The average length of recombinant exogenous inserts was about 1.49 kb. Five positive cDNA clones were obtained. Conclusion The constructed cDNA expression library shows appropriate contents and size of cDNA fragments and the related genes of Psilgramma menephorn major allergens were harbored successfully, which lays the foundation for the positive clone identification and further analysis.

The 3-D reconstruction of the nasal airway to model and analyze the airflow / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the nasal airflow-field in relation with the structure and function of the human nose.@*METHOD@#The 3-D finite-element mesh is developed from Spiral- CT imaging scans of the 25 healthy volunteers' noses. Given three preconditions, the nasal air-flow is described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 10 min, then the whole airflow patterns are obtained for further analysis.@*RESULT@#(1) In 5 cases, the airflow passes mainly through the middle medial region in both sides in the nasal airway. In remaining 20 cases, the airflow passes mainly through the middle and ventral medial regions in one side in the nasal cavity while little air passes through middle medial regions in another the other side through which little air passes. (2) The differences of velocity in the nasal valve, middle and ventral medial regions of the nasal airway between mainly side and non maingnot-mainly side are of statistical significance, while those in the olfactory split, middle and inferior meatuses in both sides are of no statistical significance. (3) In the mainly side, the most rapid air speed occurred in the nasal valve , the second rapid velocity in the middle medial region and the third in the ventral medial regions, the slowest velocity in the olfactory split, middle and inferior meatuses. In notion- mainly side, the velocity in all regions is slow without statistical significance.@*CONCLUSION@#(1) At the inspiratory flow rate of 10 L/min, the middle and ventral medial regions act as the main airways in nasal cavity. (2) The airflow in nasal cavity can be directed effectively and reasonably by nasal valve, inferior turbinate, middle turbinate in turn, which may be consistent with the nasal cycle functionally.

Quantification study of bone adaptive model based on experiment of rapid-growing rats in different stress environment / 生物医学工程学杂志

Presented is a method to set up a quantification model of bone growing and remodeling adaptation, which integrates animal experiments, parameter identification of mathematical functions and technique of computer simulation. By designing a new animal experiment, we investigate the effects of growing and remodeling of the rat femurs in different stress environments, gather the bone mineral density (BMD) of proximal femur in the same interval for the unknown parameter (B and K) inversion of bone growing and remodeling equation and create the femur three-dimensional geometrical model based on CT images. The model in this paper can not only numerically measure the relation between outer stimulus and the femur BMD variation of rapid growing rats, but also predict the growth trend of rat femur under different stress environments in its whole lifecycle. The thought and method of creating the model in this paper can be used for reference to modeling human bone growth and remodeling.