News on alginate recovery by forward osmosis: Reverse solute diffusion is useful.

The water content in the recycled alginate solutions from aerobic granular sludge was nearly 100%. Forward osmosis (FO) has become an innovative dewatering technology. In this study, the FO concentration of sodium alginate (SA) was investigated using calcium chloride as a draw solute. The reverse solute flux (RSF) of calcium ions in FO had a beneficial effect, contrary to the findings of previous literature. The properties of the concentrated substances formed on the FO membrane on the feed side were analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, verifying that calcium alginate (Ca-Alg), which can be used as a recycled material, was formed on the FO membrane on the feed side owing to the interaction between SA and permeable calcium ions. Water flux increased significantly with the increase in calcium chloride concentration, while the concentration of SA had little influence on the water flux in FO. Based on this discovery, we propose a novel method for the concentration and recovery of alginate, in which the RSF of calcium ions is utilized for recovering Ca-Alg by FO, with calcium chloride as a draw solute.

Pilot study of pressure-flow properties in a numerical model of the middle ear.

Background: Constructing a three-dimensional (3D) model through non-invasive techniques will greatly benefit the diagnosis and treatment of otitis media. However, such a model should reflect the physiological characteristics of the middle ear; in particular, the pressure-flow responses determine the validity of the model. Objectives: A 3D model of the middle ear was constructed by digital scanning and simulation. The pressure-flow properties in the model were measured to evaluate whether the model could reflect the real middle ear under physiological and pathological conditions. Materials and methods: Computed tomography (CT) scanning data from a healthy woman were input into Mimics 20.0 to construct 3D images of the middle ear. The 3D images were treated with Ansys 15.0 for finite element mesh generation. Msc Nastran 2014 were used for the fluid-solid coupling calculations. Results: The pressure-flow rate in the model resembled a Venturi tube, namely, the pressure decreased with increasing flow velocity, especially in the Eustachian tube. In the absence of the right mastoid process, the differences in air pressure and the maximal velocity in the model were reduced. Conclusions: This numerical model based on CT images of the middle ear recapitulates the biomechanical characteristics of the real middle ear. Significance: This study provides an easy and rapid approach to constructing a middle ear model for diagnosis and treatment of otitis media.

Comparison of airflow characteristics after Draf â ¢ frontal sinus surgery and normal person by numerical simulation.

Draf III frontal sinus surgery is confirmed as an effective surgical treatment for refractory sinusitis and frontal sinus tumors, etc. Although it has been reported to improve symptoms and reduce the recurrence rate of polyps significantly, the study of airflow characteristics in frontal sinus after Draf III is still rare, especially compared with normal person. This study was designed to describe the airflow characteristics of frontal sinus after Draf III procedure and differences compared with normal subject. One patient with refractory sinusitis received Draf III procedure15 months ago, and one normal person were selected retrospectively. The two subjects reported no discomfort and no abnormalities in their paranasal sinus within computed tomography scans. Computational fluid dynamics and numerical simulation calculation was performed with the finite volume method. The quantitative indexes of airflow in the frontal sinus of Draf III and normal subjects were achieved. Areas of relatively high-pressure and high wall shear stress located in a posterior part of frontal sinus ostium in both models. Inside frontal sinus, pressure and velocity of flow between Draf III and normal models were statistically significant differences (p < 0.01) after analyzed by Mann-Whitney U test. But airflow pattern of each section in frontal sinus was basically the same. Draf III sinus surgery is able to achieve nasal airflow patterns similar to those of normal person. Although values of airflow pressure and velocity were different from normal person, patients could have no subjective discomfort after surgery. "Frontal T" structure is a key anatomical site interacted with airflow to be an important cause of postoperative edema after Draf III procedure.

[Expression, Purification and Structure Prediction of Hum s1, a Major Allergen of Humulus Scandens].

OBJECTIVE: Hum s1, a major allergen of Humulus Scandens, was cloned, expressed and purified. Its protein structure and function was predicted and analyzed, which provided a foundation for further studies into the diagnostic and therapeutic efficacy of the recombinant allergen. METHODS: The target gene was amplified by PCR and sub-cloned into the expression vector pET32a through Kpn I /Xho I site. The recombinant plasmid was transformed into clone strain E. coli DH5α. The positive recombinant plasmid identified by PCR was transformed into expression strain E. coli BL-21. The expressed fusion protein was induced by IPTG, and purified using fast protein liquid chromatography. The structure and function of the protein was predicted and analyzed. RESULTS: Prokaryotic expression plasmid pET32a-G2 was constructed successfully. Hum s1 was expressed and purified. The purity of expressed fusion protein exceeded 90%. It has three potential antigen epitopes and two EF-hand structural domains. A three-dimensional model was successfully constructed. The recombinant protein was proved to have immunological activity, with ELESA showing good attachment to sera samples of patients who were allergic to Humulus Scandens. CONCLUSION: Prokaryotic expression vector of Hum s1 was successfully constructed. The recombinant protein was expressed and purified, with its epitope and three-dimensional model being predicted by bioinformatics. The study provided a basis for further development of recombinant vaccines.

The PPARγ agonist, rosiglitazone, attenuates airway inflammation and remodeling via heme oxygenase-1 in murine model of asthma.

AIM: Rosiglitazone is one of the specific PPARγ agonists showing potential therapeutic effects in asthma. Though PPARγ activation was considered protective in inhibiting airway inflammation and remodeling in asthma, the specific mechanisms are still unclear. This study was aimed to investigate whether heme oxygenase-1 (HO-1) related pathways were involved in rosiglitazone-activated PPARγ signaling in asthma treatment. METHODS: Asthma was induced in mice by multiple exposures to ovalbumin (OVA) in 8 weeks. Prior to every OVA challenge, the mice received rosiglitazone (5 mg/kg, p.o.). After the mice were sacrificed, the bronchoalveolar lavage fluid (BALF), blood samples and lungs were collected for analyses. The activities of HO-1, MMP-2 and MMP-9 in airway tissue were assessed, and the expression of PPARγ, HO-1 and p21 proteins was also examined. RESULTS: Rosiglitazone administration significantly attenuated airway inflammation and remodeling in mice with OVA-induced asthma, which were evidenced by decreased counts of total cells, eosinophils and neutrophils, and decreased levels of IL-5 and IL-13 in BALF, and by decreased airway smooth muscle layer thickness and reduced airway collagen deposition. Furthermore, rosiglitazone administration significantly increased PPARγ, HO-1 and p21 expression and HO-1 activity, decreased MMP-2 and MMP-9 activities in airway tissue. All the therapeutic effects of rosiglitazone were significantly impaired by co-administration of the HO-1 inhibitor ZnPP. CONCLUSION: Rosiglitazone effectively attenuates airway inflammation and remodeling in OVA-induced asthma of mice by activating PPARγ/HO-1 signaling pathway.

Numerical analysis of the relationship between nasal structure and its function.

The functions of the nasal cavity are closely related to its structure. In this study the three-dimensional finite element models were established based on the clinical data of twenty-four volunteers to study the influence of nasal structure on nasal functions of heating the inhaled airflow. Numerical simulations mainly concerning the airflow distribution and the airflow temperature are performed. The character of airflow heating process in these models is gained from the simulation results of these nasal cavities. The parameters describing the geometry of nasal cavity, such as the surface area of nasal airway and the volume of nasal cavity, are considered to be related to the nasal function of heating the inhaled airflow. The approximate function describing the relationship between the geometric parameters of the nasal airway and the nasal functions is gotten. This study can provide a numerical platform for studying some clinical problems and will contribute to the further research on the relationship between nasal structure and nasal functions.

[Construction and identification of the expression library of album pollen allergens cDNA].

AIM: To construct and identify the express library of album pollen allergens cDNA. METHODS: Total RNA were extracted from the album pollen with TRIzol reagent and the mRNA was isolate for the amplify followed. A double stranded cDNA (ds cDNA) was synthesized using primers containing Xho I and Poly(dT) sequence by ZAP Express®cDNA synthesis kit. The ds cDNA was modified and purified by gel chromatography, and then the cDNA fragment with the length of more than 400 bp containing sticky ends was obtained. The cDNA fragment was ligated with Uni-ZAP XR vector and subsequently treated with in vitro packaging using phage by ZAP-cDNA express GigapackIII Gold cloning kit. The express library of album pollen cDNA was constructed by in vitro packaging. The recombination rate and the lengths of fragments inserted of the cDNA library were detected by polymerase chain reaction. RESULTS: The titer and the recombination rate of cDNA expression library constructed were 9.7×10(5) and 100%, respectively. The capacity of the library was 4.85 Pfu. The average length of cDNA fragments inserted was about 1.0 kb. CONCLUSION: Based on the capacity of cDNA expression library constructed and the length of cDNA insertion fragments, the cDNA expression library constructed is qualified to screening target cDNA clone, laying the foundation for preparation of gene recombinant allergen pollen vaccine.

[Effect of septoplasty or in combination with out fracture of the inferior turbinate on the airflow field and nasal airway].

OBJECTIVE: To explore the effect of septoplasty or in combination with out fracture of the inferior turbinate in patients with nasal septum deviation on the airflow field and the nasal airway structure. METHODS: Six patients with nasal septum deviation underwent spiral CT imaging scans before surgery and during the follow-up. The 3D finite element meshes of the nasal airway were developed from the above CT scans. Given three preconditions, the nasal airflow fields were described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 12 L/min. The whole airflow patterns were obtained and then compared with the airflow filed and airway structure changes before and after surgery. SPSS 12.0 software was used to analyze the data. RESULTS: Before surgery, area of the common airway and the middle and ventral medial regions in the concave side were (1.61 ± 0.18), (0.40 ± 0.10), (0.40 ± 0.14) cm(2) respectively, and those of convex side were (1.30 ± 0.18), (0.33 ± 0.05), (0.36 ± 0.10) cm(2) respectively. The differences between both sides were of no statistical significance (Z value was 1.782, 1.363, 0.526 respectively, all P > 0.05). Airflow of the above airways were (361 ± 68), (131 ± 25), (100 ± 28) ml respectively in concave side and (178 ± 33), (59 ± 26), (59 ± 18) ml respectively in convex side, which differences were significant statistically (Z value were 2.207, 2.201, 2.201 respectively, all P < 0.05). The inferior turbinate in concave side [(0.93 ± 0.10) cm] was statistically (Z = 2.214, P < 0.05) bigger than that in convex side [(0.58 ± 0.12) cm] before surgery. The airflow fields were in disorder in both ill-airways. After surgery, area of the common airway was (2.55 ± 0.44) cm(2) in concave side and (2.20 ± 0.72) cm(2) in convex side respectively, and area of the middle and ventral medial regions in the convex side were (0.58 ± 0.13), (0.81 ± 0.26) cm(2) respectively, which differences were of significance statistically when comparing to areas before surgery (Z value were 2.201, 2.201, 2.201, 2.201, P < 0.05). The airflow passed through nasal airway orderly in both sides. But the thickness of inferior turbinate was (0.73 ± 0.08) cm in concave side after surgery, which difference was significant statistically in comparison to that before surgery (Z = 2.264, P < 0.05). Consequently, nasal resistance decreased from (0.41 ± 0.03) kPa×L(-1)×s(-1) to (0.16 ± 0.01) kPa×L(-1)×s(-1) after surgery, the difference was significantly (Z = -2.207, P = 0.027). CONCLUSION: Septoplasty or in combination with out fracture of the inferior turbinate, followed by the self-adaptation consecutively, could improve the airway and breathing capacity of the nose.

Inhibition of cGMP phosphodiesterase 5 suppresses matrix metalloproteinase-2 production in pulmonary artery smooth muscles cells.

1. It has been shown that the beneficial effects of phosphodiesterase (PDE) 5 inhibition on pulmonary hypertension (PH) are associated with the induction of vascular relaxation and suppression of the proliferation of pulmonary artery smooth muscle cells (PASMC). In the present study, we investigated whether PDE5 inhibition affects the production and/or secretion of matrix metalloproteinases (MMPs) in PASMC, resulting in extracellular matrix remodelling in the pulmonary vasculature and, thus, the development of PH. 2. Primary cultured PASMC were stimulated with endothelin (ET)-1 and MMP-2 production and RhoA activation were then determinded using gelatin zymography and a GTP-bound RhoA assay, respectively. The effects of the selective PDE5 inhibitor sildenafil and subsequent protein kinase G-specific inhibitor Rp-8Br-cGMPs on MMP-2 production and RhoA activation were further exmamined. 3. Endothelin-1 (1-1000 nmol/L) concentration-dependently stimulated MMP-2 production and/or secretion in primary cultured PASMC, with 100 nmol/L ET-1 causing a 2.41-fold increase in MMP-2 production compared with control (P < 0.01). This increase in MMP-2 production was accompanied by RhoA activation, which was abolished by preincubation of cells with 10 micromol/L Y27632, an inhibitor of Rho-associated kinase (ROCK). Furthermore, 10 micromol/L Y27632 abolished the ET-1-induced production of MMP-2. 4. The selective PDE5 inhibitor sildenafil (0.1-1 micromol/L) concentration-dependently reduced the increased MMP-2 production induced by 100 nmol/L ET-1. Specifically, in the presence of 1 micromol/L sildenafil, the 100 nmol/L ET-1-induced increase in MMP-2 production was only increased 1.3-fold over that of the control (P < 0.01 vs 100 nmol/L ET-1-stimulated cells). 5. Suppression of RhoA activation was found to mediate the inhibitory effect of sildenafil on ET-1-induced increases in MMP-2 production. Furthermore, the protein kinase G-specific inhibitor Rp-8Br-cGMPs reversed the inhibitory effects of sildenafil on RhoA activation and MMP-2 production. 6. The results of the present study indicate that PDE5 inhibition suppresses RhoA/ROCK-mediated MMP-2 production by PASMC, which may contribute to the regulation of pulmonary vascular remodelling. Thus, PDE5 inhibition may benefit patients with PH through multiple mechanisms of action.

[Screening specific allergens of allergic asthma from DNA expression library of Humulus pollen].

OBJECTIVE: To screen the allergic asthma-specific allergen from complementary DNA (cDNA) expression library of Humulus pollen. METHODS: Screened the Humulus pollen lambdaTripIEx2 cDNA expression library which had been constructed using the method of immunological screening with patients' blood serum of Humulus pollen allergic asthma, extracted the positive phage DNA and the positive phage DNA, and identified by double restriction enzyme with EcoRI, Hind III and agarose gel electrophoresis. Then the DNA fragments were sequenced and the repeats and sequence homology were analyzed. RESULTS: After 3 rounds of screening, three specific allergic cDNA clone of Humulus pollen were obtained and the sequences were 868, 550 and 592 base pairs respectively. The results of sequencing showed that these three clones represented different cDNA sequences. The repeats analysis found no repeats and these clones had no high homology with any known gene. CONCLUSIONS: Three specific allergic cDNA clones of Humulus pollen obtained may be new genes. It provides a rational basis for constructing a recombinant allergen or nuclear acid vaccine.

[The role of nuclear factor kappa B activation in immune-complex-induced acute lung injury in rabbits].

OBJECTIVE: To explore the effects of nuclear factor kappa B (NF-kappaB) in rabbit immune-complex-induced acute lung injury(ALI). METHODS: Thirty rabbits were randomly divided into 5 groups, including N, M2h, M4h, M6h and M8h groups. N group was the normal control group. M2h, M4h, M6h and M8h groups were ALI model groups. The rabbits in the N group were treated with intra-tracheal injection of 1 ml normal saline and another dose of normal saline (2 ml/kg) injected via the marginal ear vein. The rabbits in the model groups were injected intra-trachea with bovine serum albumin antibody (anti-BSA)1 ml and injected with bovine serum albumin(BSA) via marginal ear vein at dose of 2 ml/kg. Then the rabbits in the N group were killed at 8 h. The rabbits in M2h, M4h, M6h and M8h groups were killed at 2 h, 4 h, 6 h and 8 h respectively. The maleic dialdehyde (MDA) concentrations, the superoxide dismutase (SOD) activity, the protein concentrations in bronchoalveolar lavage fluid (BALF) and lung wet/dry weight ratio (W/D) were measured. The cellular distribution of NF-kappaB P65 in lung tissues was determined by immunohistochemistry. RESULTS: The concentrations of MDA, protein in BALF and W/D of lung tissue in M2h, M4h, M6h, M8h groups increased significantly as compared with those in the N group. On the contrary, the activity of SOD in BALF in the model groups decreased significantly as compared with that of the N group. Increased expression of NF-kappaB in inflammatory cells was found in lung tissues from the model groups. The number of positive cells in M2h, M4h, M6h, M8h groups [(26.5 +/- 5.9), (39.9 +/- 6.9), (51.0 +/- 6.3), (58.0 +/- 5.3)] increased significantly as compared with that in the N group [(7.4 +/- 1.9), (t = 8.73 - 25.33, P < 0.01)]. CONCLUSIONS: Immune-complex-induced ALI animal models can be established by intra-tracheal injection of anti-BSA serum and venous injection of BSA. NF-kappaB may play an important role in immune-complex-induced ALI by inflammatory mechanism.

[Analysis of the character of self-adaptation of nasal structure in patients with nasal septum deviation].

OBJECTIVE: To analyze the different characters of nasal airflow-field between 10 patients with nasal septum deviation and 20 healthy Chinese people by the method of three-dimensional reconstruction of these people's nasal cavity and numerical simulation of the flow field in these nasal cavity models. The character of airflow-field was considered by analyzing the relationship between the structure and function of the human nose. METHODS: Based on the data obtained from the CT images, 10 patients with nasal septum deviation and 20 healthy Chinese people's nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models was simulated with finite element method. The different characters of nasal airflow-field was analysed between two groups of people. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity. The airflow for patients with nasal septum deviation mainly passed through the broad nasal cavity, especially in the middle part of meatus of nose. In the healthy people group, the airflow mainly passed through the main side of the nasal cavity, especially in the middle and inferior part of the meatus of nose. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. In the patients with nasal septum deviation, the pressure mainly dropped in the part of the nasal septum deviation, accounting approximately 71.36% of the total pressure drop. In the group of healthy people, the pressure dropped mainly in the limen nasi, accounting approximately 58.78% of the total pressure drop. The nasal airway resistance of the patients with nasal septum deviation was larger than that in the group of healthy people. CONCLUSIONS: The three-dimensional nasal airway can reflect the characters of the human nasal airway. It can be used to analyze the change of the aerodynamic in nasal cavity caused by the abnormal anatomy of the nose. This experiment can proof that human nose has the function of self-adaptation, it can build a foundation for the construction of the model of self-adaptation of the human nose.

[Analysis of the allergenicity and immunogenicity of Psilogramma menephron allergen].

OBJECTIVE: To analyze the allergenicity and immunogenicity of Psilogramma menephron allergen so as to provide the basis for preparing recombinant and standardized allergen vaccines of Psilgramma menephorn. METHODS: The extracts of Psilgramma menephorn were analyzed by SDS-PAGE, and the allergenicity and immunogenicity of the extracts were tested with 9 sera from allergic patients by means of immunoblotting. RESULTS: More than 20 allergen proteins were separated from the extract of Psilgramma menephorn by SDS-PAGE, with the relative molecular weight ranging from 12,000 to 128,000. The relative molecular weight of the allergenic proteins were 74,000 (88.9%), 66,000 (22.2%), 49,000 (22.2%), 36,000 (77.8%), or 25,000 (33.3%), and those of the immunogenic proteins were 79,000 (33.3%), 74,000 (66.7%), 66,000 (22.2%), 49,000 (22.2%), 36,000 (44.4%), or 25,000 (55.6%). CONCLUSION: The relative molecular weight of the major allergenic proteins of Psilgramma menephorn are 74,000 and 36,000, and 74,000 and 25,000 for the major immunogenic proteins. These proteins constitute the major allergenic components for diagnosis and specific treatment of Psilgramma menephorn allergy.

[Purification and analysis of the immunoactivity of humulus pollen allergen].

OBJECTIVE: To purify the humulus pollen allergen and study the allergenicity and immunogenicity of it. METHODS: Crude humulus pollen extracts were purified by gel filtration with Sephadex G-75 and Sephacryl S-200HR. Various fractions of the allergen protein were collected respectively. The molecular weights of protein were confirmed by SDS-PAGE. The inhibition rate and reaction rate with sIgG and sIgE of patient's serum were determined by ELISA inhibition test and western blotting. RESULTS: Two peaks were obtained from crude humulus pollen extracts by gel filtration of Sephadex G-75. The first peak contained most of protein while the second peak contained little protein and lots of pigments. So the second peak was thrown away. P solution which contained the first peak and valley fraction were purified by gel filtration of Sephacryl S-200HR and four components that included the 1st peak, the valley, the 2nd peak and the end fraction were obtained. The results of electrophoresis demonstrated that purified humulus pollen contained more than 20 kinds of protein with the molecular weights ranged from 5.0 x 10(3) to 97.4 x 10(3). The fraction of the 1st peak contained protein with the molecular weights ranged from 43 x 10(3) to 97.4 x 10(3), and the fraction of the valley and the 2nd peak contained protein with the molecular weights ranged from 5.0 x 10(3) to 43 x 10(3). The fraction of the end contained protein with the molecular weights lower than 5.0 x 10(3). The results of ELISA inhibition test showed that the inhibition rate of the 1st peak, the valley, the 2nd peak and the end fraction to sIgG were 68%, 70%, 95%, 5% respectively, and those to sIgE were 25%, 64%, 71%, 11% respectively. The results of western blotting demonstrated that the reaction rate of the 1st peak, the valley, the 2nd peak and the end fraction with sIgG of patients' serum were 65.63%, 78.13%, 87.50%, 6.25% respectively, and those with patients' sIgE were 25.00%, 71. 88%, 84.38%, 15.63% respectively. CONCLUSION: Humulus pollen contained more than 20 kinds of protein. The proteins with molecular weights ranged from 5.0 x 10(3) to 43 x 10(3) were the major allergen with strong allergenicity and immunogenicity. The proteins with molecular weights ranged from 43 x 10(3) to 97.4 x 10(3) were subordinated allergen with strong immunogenicity and weak allergenicity.

[Cloning, screening and sequence analysis of the major allergens of Psilgramma menephorn].

OBJECTIVE: To identify and isolate the genes encoding the allergens of Psilgramma menephorn by screening the cDNA expression library. METHODS: The cDNA expression library of Psilgramma menephorn was constructed in lambdaZAPIIphage, and the library was screened using the sera from the patients allergic to Psilgramma menephorn and those from the rabbits immunized with Psilgramma menephorn extracts. The positive clones were subcloned into pBluescript plas, and the cDNA in the positive clones were amplified with PCR and sequenced. RESULTS AND CONCLUSION: Five positive clones were obtained by immunological screening of 5 x 10(4) recombinants. Sequence analysis showed that the positive clones contained the new genes of Psilgramma menephorn allergens. This success in isolating these genes may facilitate the development of specific immunotherapy against Psilgramma menephorn allergy and further research of allergic diseases.

[Application of serum surface-enhanced laser desorption/ionization proteomic patterns in distinguishing non-small cell lung cancer patients from healthy people].

OBJECTIVE: To explore the application of serum surface-enhanced laser desorption/ionization (SELDI) marker patterns in distinguishing non-small cell lung cancer patients from healthy people by protein chip technology. METHODS: One hundred and sixty-three serum samples (123 patients with lung cancer and 40 healthy persons), were randomly divided into a training set [94 cases, 53 non-small cell lung cancer (NSCLC), 21 small cell lung cancer and 20 healthy persons] and a blinded test set (69 cases), were included for analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Five protein peaks at 11,493, 6,429, 8,245, 5,336 and 2,536 were automatically chosen for the system training and the development of a decision classification tree model (marker pattern). The accuracy of the model was tested with the blinded test set (an independent set of masked serum samples from 49 patients with NSCLC and 20 healthy persons). RESULTS: The model differentiated the patients with NSCLC from the healthy people with a sensitivity of 95.9% (71/74) and a specificity of 90.0% (18/20) in the training set and a sensitivity of 83.7%, and a specificity of 80.0% in the blinded set respectively. CONCLUSION: SELDI-TOF-MS technique can correctly distinguish NSCLC patients from healthy people, and it has the potential for the development of a screening test for the detection of NSCLC.

[Structure of nasal cavity and characters of airflow].

OBJECTIVE: To study the airflow in nasal cavity by reconstructing 20 volunteers' nasal cavity models and numerical simulation of the flow field in these nasal cavity models. METHODS: Based on the data from the CT images, 20 volunteers' nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models were simulated with finite element method. Some of these volunteers were tested by means of acoustic rhinometry and the test results recorded. Comparisons were performed for the curves from acoustic rhinometry and the results of numerical simulations. The simulation results were explained with the fluid network theory. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity plot. Main airflow would pass through the common nasal meatus in which flux accounted for 50% - 77% of overall flux. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. The nasal airway resistance in the region of limen nasi accounted for 50% - 65% of overall nasal airway resistance. Comparing the test results with the simulation results the relation could be understood between the change of the cross-section area of nasal cavities and the plot of numerical simulation results of velocity and pressure in airflow field in the nasal cavity models. CONCLUSIONS: Comparing the simulated results of the 20 volunteers' nasal cavity model it can be concluded that the distribution of airflow in nasal cavities is not stationary. The differences among everybody's nasal cavity structure lead to the different airflow distribution in the nasal cavities.

[Observation of maxillary mucosa restoration after the endoscopic sinus surgery operation of chronic sinusitis and nasal polyps].

OBJECTIVE: To understand the restoration process of the mucosa through the continual endoscopic, microscopic, transmission electron microscopic and scanning electron microscopic observation of the nasal mucosa after endoscopic sinus surgery (ESS). This restoration process of mucosa can be used to appraise the effectiveness of the operation. METHODS: Thirty-one cases (53 sides) with chronic nasal sinusitis and nasal polyps were selected randomly, which had been undergone ESS operation during January to December, 2001. Biopsy of posterior frontanelle of the maxillary sinus were performed to observe the mucosa changes before the ESS and at 2-3 weeks, 8-11 weeks and 13-16 weeks after the ESS, respectively. RESULTS: Epithelia shedding, proliferation, squamous metaplasia, glandular and fibrous tissue proliferation and lymphocytes infiltration were observed in all cases before the ESS. The microtubule abnormal and mitochondria diminishing and expanding existed in all cases. The morphological changes were not significant within 2-3 weeks after the ESS compared to the changes before the ESS. Eight-eleven weeks after the ESS, the nasal cavity turned clean and smooth. The number of pillar cells increased and the cilia swelling, short cilia, and many pillar cells with microvillus were seen. The number of goblet cells increased. Pathological glandular and fibrous proliferation were seen in all cases (53 sides). The operated cavity was clean and covered completely by epithelia (50 sides) 13-16 weeks after ESS. The length of cilia increased and arrangement of the cilia line was in the same direction. The structure of microtubules was clear. The mitochondria was elongated and became dense (49 sides). The pathological repairing was at work (3 sides). CONCLUSIONS: After the ESS, the recovery of the mucus needs 3 months. Some pathological changes are irreversible and the cilia pathological change is related with its restoration. The more cilia reserved and timely local cleaned after ESS, the more helpful to the restoration of the cilia morphology and function. The effective of ESS can be evaluated through the histological-morphological changes. timely local cleaned after ESS, the more helpful to the restoration of the cilia morphology and function. The effective of ESS can be evaluated through the histological-morphological changes.