Mucus secreted mainly by epithelial goblet cells and submucosal glands covering the respiratory tract plays an important role in the protection from external aggressions, such as solid particles, pathogens and chemical agents by mucociliary clearance. The viscoelastic properties of mucus are mainly determined by the presence of extensively-glycosylated high molecular weight mucins. A lot of factors influence the expression and secretion of mucins in airway, lead to mucus overproduction, which is a distinguishing feature of chronic obstructive pulmonary disease (COPD) and causes disruption of the mucociliary clearance function, resulting in airway block, chronic infection and death.

Objective To evaluate the clinical effect and safety of the occiput-cervicle or C1-C2 internal fixation and bone graft fusion in treatment of the unstable atlas fracture.Methods A retrospective study was performed in 38 patients with unstable atlas fractures treated by the occiput-cervicle or C1-C2 internal fixation and bone graft fusion from October 2004 to March 2009.Six patients with comminuted atlas fracture combined with instability of the occipito-atlantoid articulations were treated with occiput-C2 fusion(five patients)and with occiput-C3 fusion(one patient).There were seven patients with typical Jefferson fractures,three with semiring fractures,eight with atlas fractures combined with Anderson type Ⅱ odontoid process fractures,three with atlas fractures combined with Hangman's fractures (two patients with Levine and Edwards type Ⅲ Hangman's fractures were treated with occiput-C3 fusion and one patient Levine and Edwards type Ⅱ Hangman's fracture was treated with C1-C2 fusion),three with atlas fracture combined with lower cervicle injury,six with rupture of transverse ligament combined with instability of atlanto-axial joint(Dickman transverse ligament type Ⅰ injury)and two with comminuted fracture of the lateral mass associated with bony avulsion of the medial tubercle and transverse ligament(Dickman transverse ligament type Ⅱ injury).Of all,five patients were treated with occiput-C2 fusion,three treated with occiput-C3 fusion and 30 treated with C1-C2 fusion.Results All the patients were followed up for a range of 12-46 months(average 28 months),which showed improvement of clinical symptoms in some extent postoperatively.The operation time ranged from 80 to 190 min ates(average 135 minates),with intraoperative blood loss for 200-3 300 ml(average 460 ml)and average fluoroscopic time for 60 seconds.There were no neurological deficits,vertebral artery related complications or other complications in all the patients during the surgical operation.No neurological deficit was aggravated after the patient's mobilization with brace three days after operation.The enous plexus of blood vessel at C1-C2 rupture induced by the use of electrocautery was found in three patients who showed no cerebral hemodynamic deficit after hemostasis with hemostatic sponge and cotton piece.The follow-up X-ray and CT manifested osseous fusion in all the patients,with no looseness or breakage of the screws.The late follow-up showed pain associated with movement and limited range of motion in four patients(11%)and occipital neuralgia in one.Conclusions An occiput-cervicle fixation fusion or a C1-C2 fixation fusion combined with short external fixation can reestablish the upper cervical stability and prevent further injury of the spinal cord and nerve function and hence is an ideal option for C1 burst fracture with or without rupture of the transverse ligament.

ObjectiveTo investigate application of the anterior cervical pedicle screw in the lower cervical spine.MethodsTwenty disarticulated human vertebrae(C3-C7) were evaluated with computed tomography for pedicle morphometry Parameters included vertebral body height,vertebral body depth,vertebral body width,outer pedicle width,outer pedicle height,pedicle axis length,transverse section angle,sagittal section angle,transverse intersection point distance and sagittal intersection point distance.On the basis of these data,the screw channel was determined and the screws were inserted in the specimen.Five patients underwent surgical reconstruction using anterior pedicle screw fixation.After surgery,physical examination and roentgenograms and CT scans were performed in all patients.ResultsThe transverse section angle increased from C3(45.7°±4.0°) to C5(52.1°±5.9° ),but decreased from C6(47.8°±6.7°) to C7(44.4°± 8.3°).The sagittal section angle gradually increased from C3 (93.4°±7.2°) to C6( 112.1°±6.2°) but decreased a little to C7(102.7°±8.5°).The distances in transverse section was about 1.97-3.98 mm and in sagittal section was 3.4-7.5 mm.Anterior pedicle screws were inserted successfully in all specimens without critical pedicle wall perforations.Patients were permitted to ambulate the next day after surgery with a cervical collar.Postoperative neurological improvement was observed in all cases.Postoperative radiographic evaluation confirmed proper insertion of anterior pedicle screws without pedicle perforaton.The average follow-up time was 10.6 months.No anterior pedicle screw breakage and loosening was observed.ConclusionThe entry point in anterior pedicle screw should located in 5mm to upper endplate and near anterior median line.The transverse section angle should be 45.7°-52.1°and the sagittal section angle should be 93.4°-112.1°.The lengths of the screw should be about 32 mm.

Objective To investigate feasibility and safety of anterior pedicle screw fixation tunnel in the axis so as to provide theoretic evidence for further clinical application.Methods Thirty-two dry axis specimens were used for anterior pedicle screw placement,and the length of pedicle crews tunnel was measured by a digital caliper.The extraversion angle and the downslope angle were determined by CT cross-sectional scanning and reconstruction.Results All the anterior pedicle screws were positioned well,with no perforation of the pedicle.The anchoring point was at the vertex between the vertebral body and the superior articular process,with axis pedicle length of(28.4 ± 2.5)mm,the extraversion angle of (28.5 ±2.3)°and the downslope angle of(15.5 ±2.0)°.Conclusions Anterior pedicle screw fixation tunnel is feasible in the axis and can keep away from some important anatomy structures including transverse foramen,vertebral artery groove and vertebral canal to provide large safety space.

Objective To investigate the effect of gut bacteria under chronic colitis on the progression of hepatoma in mice.Methods 22 hepatitis B virus (HBV) -transgenic mice ( male, 8 weeks) were randomly divided into two groups, one group (n =10) was fed the drinking water containing 2% dextran sodium sulphate(DSS)to induce chronic colitis and the control group(n =12)was fed with normal drinking water.In order to investigate the effect of gut microbes, 7 male HBV-transgenic mice(8 weeks, with no detectable hepatoma under microscopy) were cohoused with 4 mice with hepatoma for 16 weeks.Results No significant liver cell damage was observed in the group of the mice fed with 2% DSS-containing drinking water.By the 22 -week old,9 of the 10 mice(90.0%) fed with 2% DSS-containing drinking water, 2 of the 12 mice(16.7%) fed with normal drinking had hepatoma.Both the hepatoma incidence and the tumor numbers in the group of mice fed with DSS-containing water were significantly higher than that in the controls (P =0.002 and P =0.028respetively).Compared to controls, the bacteria family Prevotella (P =0.022) and Anaeroplasma (P =0.014) reduced significantly in the mice with induced chronic colitis.All the mice (n =7) cohoused with the mice with hepatoma had the liver tumor developed at 24 -week-old.Conclusion Alterations of gut bacteria under chronic colitis may promote the development of liver cancer.

Objective To investigate the safety of the occipital condylar screw with vertical position and evaluate the selection strategy of the posterior approach of the posterior occipital condylar screw in Chinese people.Methods The clinical imaging data of 60 outpatients from September 2013 to September 2015 were retrospectively analyzed,36 male and 24 female,the average age was 41.6±9.2 (range from 25-58),Excluded occipitocervical injury,tumor and deformity patients.We built a three-dimensional digital model and simulated placing screw by utilizing CT data on Mimics software,after that we took the occipital condyle posterior medial and lateral midpoint as the entry point,then made 2 points equidistantly to the midpoint in vertical direction.We put 3.5 mm diameter virtual screws in 4 different conditions:largest cranial angle,smallest cranial angle,longest screw path and shortest screw path.Then we assessed the anatomical relationship between the screw and the hypoglossal canal or the atlanto-occipital joint by a three-dimensional window and measured the cranial angle,medial angle and length of screw path,then calculated the safety angle of the cranial angle,the successful rate of setting screw,and compared the safety of different screw points by 3-Matic software.Results 120 occipital condyles were obtained from the CT data of 60 patients by Mimics software.There was no significant difference in the data of the cranial angle,medial angle,safety range and length between both left and right sides.The obtained safe cranial angle of each point respectively was 20.9°±6.0° (lowest point),17.0°±6.2° (middle point),and 11.6°±7.1°(top point),obviously the largest angle was in the lower point and the smallest was in the top point.The difference was statistically significant.We then acquired the successful rates of different cranial angle of each point,the highest successful rate was 99.17％,96.67％,74.17％ in lowest,middle and top point when cranial angle were 3°or 4°,3°and 0°respectively.The successful rates of lower point and niddle point were significantly higher than the top point,and the difference was statistically significant.The medial angle parameters obtained were 34.41°±2.59°on left and 34.06°±2.44°on right,and there was no significant difference.The length parameters of the longest screw path acquired were 23.09± 1.47 mm,22.84± 1.40 mm and 23.15± 1.45 mm at top,middle and lowest entry point.The average value of shortest screw path of each point was 21 mm,and there was no significant difference among every entry point.Conclusion Among the occipital condyle posterior screw entering points,selecting the lower point can improve the success rate and safety;the change of nail enter point in the vertical direction has little effect on the length of the nail.We can increase the safety and reduce the risk of occipital condylar screw placement as far as possible through the three-dimensional digital technology.

Objective To evaluate the clinical effect of postural reduction combined with miniincision screw-rod system and percutaneous kyphoplasty (PKP) in treating osteoporotic thoracolumbar burst fractures.Methods A retrospective case series study was performed for data of 35 patients with osteoporotic thoracolumbar burst fractures without neurological deficits undergone mini-incision screw-rod system fixation and PKP between January 2012 and January 2014.There were 14 males and 21 females,with a mean age of 63.2 years (range,50-72 years).Operation time,intraoperative blood loss,complications,visual analogue score (VAS),height of fractured vertebrae and kyphosis Cobb angle were recorded.Results Operation time was (49.6 ± 6.8) min,and intraoperative blood loss was (45.6 ±7.8)ml.All patients were followed up for 9-18 months (mean,13.5 months).No intraoperative or postoperative serious complications occurred,including intracanal cement leakage,breakage or loosening of the screws.VAS of back pain was decreased from (8.4 ± 1.1)points preoperatively to (3.5 ± 0.6)points postoperatively (P ＜ 0.05).Height of the fractured vertebrae was improved from (49.62％ ± 5.68)％ preoperatively to (86.64 ± 6.63) ％ postoperatively (P ＜ 0.05).Kyphosis Cobb angle was improved from (28.12 ± 1.06) °preoperatively to (5.15 ± 1.08) °postoperatively (P ＜0.05).At the final follow-up,VAS was further decrease and vertebral height and Cobb’ s showed a slight loss of correction.Conclusion Postural reduction combined with mini-incision screw-rod system and PKP can relieve back pain,restore the height of injured vertebrae,correct kyphotic deformity and reduce operation time and blood loss,indicating a minimally invasive,safe and effective procedure for treatment of osteoporotic thoracolumbar burst fractures.

Objective To identify the feasibility and the anatomical parameters of posterior transarticular pedicle screw fixation in the thoracic spine, provide a reference for clinical applications. Methods Twenty human cadaveric thoracic spine segments were dissected posteriorly and anteriorly, with care taken to expose the laminas and pedicles. The entrance point of transarticular pedicle screws was located in the 7 mm away from the above at the inferior margin of the lamina and the inside at the exterior margin, respectively. Posterior transarticular pedicle screws implantation was performed under direct visualization into T1,2,T5,6 and T9,10 Under direct abservation, the feasibility of posterior transarticular pedicle screw fixation was assessed. Then a CT was done. On the morphologic CT scan, the angle and length of the transarticular pedicle crew trajectory were measured. Results The thoracic transarticular pedicle screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the axial plane with successful placement. Screws were placed across the facet joint, and from the inferior articular process of upper thoracic vertebra into the pedicle of lower thoracic vertebra. There was little difference between different number of thoracic vertebrae of the angle, but without significance. The average angles of the screws were 41.4°+3.2°caudal tilting in the sagittal plane and 2.1°±0.7° lateral tilting in the axial plane. The average trajectory lengths were (40.6±4.9)mm, and the lengths increased gradually from upper thoracic vertebra to middle and lower. There were significant differences statistically among T1,2, T5,6 and T9.10 (F=74.09, P＜0.01 ). Conclusion Posterior transarticular pedicle screw fixation is feasible, and there are some directions for implantating the screws. Transarticular pedicle fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.

ObjectiveTo evaluate the clinical effects of transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion(PLIF) using microendoscopic discectomy under X-Tube system in treatment of lumbar degenerative disc diseases.MethodsFrom December 2007 to April 2008,32 patients with low back disorders were treated by microendoscopic discectomy TLIF or PLIF under X-Tube system,including 19 cases in TLIF and 13 in PLIF.Etiologies including lumbar disc herniation combined with segmental instability in 21 cases,and spondylolisthesis in 11 cases.All patients were under regular postoperative follow-up and radiological examination.The clinical functional outcomes were evaluated according to Oswestry disability questionnaire.ResultsThe mean operation time was 120 min(range,90-180),and the average blood loss was 190 ml (range,100-400).There were no complications,such as infection and internal fixation failure.Bony fusion was achieved in all patients.The follow-up was from 14 months to 41 months with 21 months in the average.The average 0swestry scores decreased from preoperative 40.1％±4.1％ to 9.5％±3.7％ three months after the operation.The outcomes of this operation were rated as excellent.ConclusionMicroendoscopic discectomy TLIF or PLIF under X-Tube system in treatment of lumbar degenerative disc diseases has the characteristics of less blood loss,tissue trauma and quick recovery.

Objective To discuss the strategies for treatment of lower cervical distractive flexion injuries. Methods Sixty-eight patients including 43 males and 25 females at age range of 18-72 years (average 43 years) suffered from lower cervical distractive flexion injuries were operated from January 2002 to June 2007. According to Allen's classification, there were 7 patients at grade Ⅰ, 19 at grade Ⅱ,29 at grade Ⅲ and 13 at grade Ⅳ. Temporary skull traction was used for each subject before surgery. Only posterior approach was performed in 26 patients who were fixated by pedicle screw system,lateral mass screw system or transarticular screw system. Combined anterior and posterior approach was applied for the other 42 patients at one stage. The curative effect was followed up for all patients after the procedures. Results All patients were followed up for 6-65 months ( average 34 months), which showed posterior incision infection in 2 patients who were cured after debridement or change dressing. Two patients with aggravated neural symptome were cured following treatment with methylprednisolone. Neural function was improved at least for one level in all patients except for 18 patients (Frankel A). Of 11 patients at grade B, there were 4 patients improved to grade C and 5 to grade D. Of 10 patients at grade C, there were 6 patients recovered to grade D and 4 to grade E. All 15 patients at grade D reached grade E. It was not found loosening, breakage or defuxion. The graft bone was fused within 3-4 months, with no any complications related to surgical fixation. Conclusions The strategies for lower cervical distractive flexion injuries should be taken according to Allen' s classification. Single posterior procedure is suitable for grade Ⅰ and Ⅱ injuries. While combined posterior and anterior procedure can be used for grade Ⅲ and Ⅳ injuries.