Objective To study the impacts of dynamic compressive stress on the mRNA expression of osteopontin ( OPN ),runt related gene 2 ( Runx2 ),osteocalcin ( OC ),osterix,alkaline phosphatase (ALP) and bone morphogenetic protein 2 (BMP-2) in the osteoblasts of Sprague-Dawley (SD) rats. Methods Osteoblasts extracted from skull periosteum tissue of neonatal SD rats were digested using trypsin and collagenase （Ⅰ）,then were subcultured and amplified in vitro.ALP staining and alizarin red staining were performed to identify the purified cells.The cells were treated with compressive stress at 20,50 or 100 mmHg for 24 h.The expression levels of OPN,Runx-2,OC,osterix,ALP and BMP-2 were measured and quantitatively analysed using a real-time quantitative polymerase chain reaction. Results Under 20 mmHg of dynamic compressive stress the expression levels of OPN,Runx2,OC,osterix,ALP and BMP-2 all were elevated compared with the control group.The peak expression oecured under 50 mmHg pressure. The expression levels did not change significantly compared with the control group under 100 mmHg pressure. Conclusions Moderate dynamic compressive stress can promote the expression of OPN,Runx-2,OC,osterix,ALP and BMP-2 mRNA in osteoblasts,which might be an important mechanism for promoting the union of fractures.

Objective To investigate the biological effect of 50 Hz sinusoidal electromagnetic fields at 1 mT on the proliferation of the human osteosarcoma cell line MG-63.Methods Osteosarcrma MG-63 cells were divided into control and experimental groups.The control group was incubated without an electromagnetic field; the experimental group was incubated in a 50 Hz,1.0 mT sinusoidal electromagnetic field.On the 2nd,4th and 6th day,their proliferation was determined using a cell counting kit-8(CCK-8)assay.Variations in the cell cycle were detected with flow cytometry(FCM).Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR)was used to measure cyclin B1 and cyclin D1 mRNA.Results Compared with the control group,proliferation of the experimental group cells was reduced significantly.The percentage of cells at G0-G1 phase increased,and the mRNA expression of cyclin B1 and cyclin D1 was significantly reduced.Conclusions A 50 Hz sinusoidal electromagnetic field at 1.0 mT can inhibit the proliferation of osteosarcoma cell line MG-63 significantly.

[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.

[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 (allP<0.05); airflow of middle meatus, inferior meatus and olfactory cleft in the main-side were (2.08±0.43) m/s, (1.60±0.95) m/s, (1.64±0.80)m/s respectively, and those in non-main-side were (1.89±0.52) m/s, (1.49±0.89) m/s, (1.50±0.75) m/s respectively, which differences were significant statistically (allP>0.05); 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.

Objective To study the effects of electromagnetic field (EMF) exposure on osteoporosis in ovariectomized mice. Methods Sixty 8-week-old female Kunming mice were divided into four groups at random: a sham operation group (group A), an ovariectomized group (group B), an EMF and ovariectomized group (group C) and a nilestriol and ovariectomized group (group D). Bilateral ovariectomies were performed on all mice except those in group A. The mice of group C were exposured to a 15 Hz, 1.0 mT electromagnetic field. The mice of group D were given at nilestriol 1.5 mg/kg/week. The bone mineral density (BMD) of the lumbar vertebrae was measured before the mice were sacrificed at the 12th week. Blood specimens were collected every two weeks to measure the ac-tivity of alkaline phosphatase (ALP) and the concentration of bone gamma-carboxyglutamic-acid-containing proteins (BGP), calcium and estradiol in the serum. Histological sections were taken to examine and analyze the changes in bone trabeculae in the lumbar vertebrae after 6 and 12 weeks. Results EMF at 15 Hz and 1.0 mT intensity signifi-cantly increased the activity of ALP and the concentrations of BGP and calcium in the serum. In addition, the absorp-tion of bone trabeculae in the lumbar vertebrae was significantly restrained. Conclusions EMF at 15 Hz and 1.0 mT can restrain the development of osteoporosis in ovariectomized mice.

Objective To study the effects of an electromagnetic field (EMF) on the expression of fibro-blast growth factor (FGF-2) and it' s receptor (FGFR-2) mRNA in rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods Rat BMSCs were isolated and cultured in vitro. The subcultured cells were divided into different groups to be EMF stimulated at 1.0 mT. The expression of FGF-2 and FGFR-2 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results Different frequencies and durations of 1.0 mT EMF exposure induced FGF-2 and FGFR-2 mRNA expression in comparison to blank controls. The expression of FGF-2 mRNA reached a peak after stimulation at 15 Hz for 10 min, 50 Hz for 60 min and 75 Hz for 30 min. And the expression of FGFR-2 mRNA reached a peak after 30 minutes at all frequencies. At 1.0 mT with 30 min exposure, the expression of FGF-2 mRNA peaked after 50 Hz stimulation, and the expression of FGFR-2 mRNA peaked after stimulation at 75 Hz. Conclusions Moderate EMF stimulation can significantly increase the expression of FGF-2 and FGFR-2 mRNA in rat BMSCs in vitro.

Objective To explore in vitro the best time window for using sinusoidal electromagnetic fields to promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).Methods BMSCs were isolated and cultured from 4-week-old Sprague-Dawley rats (male and female,80-120g).The BMSCs (from passage 3) were exposed 0,1,4 or 8h/d for 7d,14,or 28d,respectively,to 15Hz sinusoidal electromagnetic fields with a maximum amplitude of lmT.Those exposed 0h/d served as the control.The relative expressions of runt related gene-2 (RUNX2),bone sialoprotein (BSP) and osteopontin (OPN) were determined using real-time,quantitative reverse transcription-polymerase chain reactions (RT-PCRs).The level of RUNX2 protein was determined by Western blotting after 14d.Alizarin red staining was used to compare calcium distribution in each group.Results Obvious promotion of differentiation to osteoblasts was observed after 7 days of exposure to the15 Hz sinusoidal electromagnetic fields,most obviously manifested by an outstanding increase of the early osteogenic index RUNX2 in those exposed 4h/d.After 14 days of intervention,the 1h/d exposure showed to be most effective,especially in inducing the changes of the late osteogenic index OPN.The trends of changes in RUNX2 protein were similar in all groups.After stimulating 1h/d for 14 and 28days,calcium deposition increased to the greatest extent.Conclusions Exposure to sinusoidal electromagnetic fields induces osteogenic differentiation to osteoblasts in rat BMSCs in vitro.There is an apparent window effect.The best results are observed with more days of exposure and shorter exposure time (1h) every day.

Objective To explore the effects of electromagnetic fields (EMFs) on osteogenesis during co-culture of bone mesenchymal stem cells (BMSCs) with osteoblasts in rats.Methods BMSCs and osteoblasts were isolated from Sprague-Dawley rats and cultured.Sub-cultured osteoblasts and BMSCs were seeded in transwell cell-culture-chamber polyester inserts to establish the co-culture system.The co-cultures were then randomly divided into a normal co-culture group and a group exposed to an EMF.Single-cultured BMSCs and osteoblasts were set as a single culture group.The EMF group was exposed to an EMF for 4 hours per day.On the 14th day,cell culture plates or inserts were randomly selected for total RNA extraction and measurement of the mRNA expression levels of Runt-related transcription factor 2,transcription factor 7,alkaline phosphatase,collagen type Ⅰ,bone morphogenetic protein 2 (BMP-2) and bone gamma-carboxyglutamate protein (Osteocalcin gene,OC gene) using real-time PCR assays.Cell culture dishes or inserts were also randomly chosen for Alizarin red staining to detect mineralized nodules.Results The level of osteogenic gene expression in single-cultured BMSCs and osteoblasts was low,while it was much higher in the co-culture group.The level of gene expression in the EMF-exposed and co-cultured group was even higher.Alizarin red staining also showed that calcium mineralized modules had increased in the stimulated,co-cultured system compared with the unstimulated,co-cultured cells.Conclusion EMF exposure can promote osteogenic differentiation of BMSCs and osteoblasts when they are co-cultured.BMP2-mediated cellular interaction might play an important role in osteogenic differentiation induced by EMF exposure.

OBJECTIVE To evaluate the effect of intravenous infusion of methylprednisolone on postoperative recovery and complications after coblation tonsillectomy.METHODS Eighty three patients who were scheduled for coblation tonsillectomy from December 2015 to December 2016 were included in this study.Firstly,they were divided into 2 groups,i.e.,the younger group (＜12 years) and the older group (≥12 years old).Secondly,these two groups were further divided into experimental group and control group by the prospective,double-blind and randomized method.The experimental group was treated with methylprednisolone and antibiotics for 3 days.Then,the postoperative reactions such as the pain,activity,pharyngeal edema,body condition,exfoliation time of the tunic albuginea,post-tonsillectomy hemorrhage were observed.RESULTS 1.From the third day to fifth day,using methylprednisolone can alleviate pain (Z=4.42,P=0.00),increase the activity(Z=2.64,P=0.00)and reduce pharyngeal edema(Z=2.84,3.10,all P=0.00) in younger group.2.After operation,in the younger group,the incidence rate of gastrointestinal discomfort in control group was higher than that in experimental group(x2=4.97,P=0.03).In the older group,the incidence rate of gastrointestinal discomfort(x2=5.24,P=0.02) and sleep disturbance(x2=5.03,P=0.03) in control group was higher than those in experimental group.3.In the older group,exfoliation average time of the tunic albuginea in experimental group was longer than that in control group(t=2.16,P=0.04).4.Secondary bleeding rate was not statistically significant in the two groups(x2=1.29,P=0.26).CONCLUSION Intravenous infusion of methylprednisolone after coblation tonsillectomy is beneficial,especially in the relief of pain,gastrointestinal discomfort and pharyngeal edema.

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.
Adult ; Asian Continental Ancestry Group ; Female ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Male ; Models, Biological ; Nasal Cavity ; diagnostic imaging ; Pulmonary Ventilation ; Tomography, X-Ray Computed