Objective:To explore the feasibility and accuracy of three-dimensional (3D) modeling methods based on ultrasound imaging data for normal and abnormal fetal cardiac structures, and to construct a methodology system for 3D printing of fetal heart based on ultrasound.Methods:A total of 93 fetuses examined in Tangdu Hospital of Air Force Military Medical University from January to December 2019 were selected. Fetal echocardiography was obtained using spatio-temporal image correlation (STIC). Ninety-three hearts were 3D modeled by blood flow modeling, blood pool modeling and cavity modeling, and printed by stereolithography technique. The data measured on the 3D digital models and 3D printed solid models were compared with the corresponding fetal echocardiographic images respectively in order to evaluate the accuracy of the modeling methods.Results:The fetal cardiac blood flow models based on Doppler flow image data showed the malformation and trend of small blood vessels. The fetal cardiac structure models printed based on blood pool modeling displayed the malformation of heart and large blood vessels. Models printed based on cavity modeling method accurately displayed valve and structural defects.For 83 normal fetal hearts, the long diameters of left and right ventricles measured on echocardiography [(15.3±1.9)mm, (13.2±1.9)mm] were compared with those measured on digital models [(15.1±1.9)mm, (12.9±1.9)mm] and 3D printed models[(15.1±1.9)mm, (13.0±1.9)mm], respectively, and there were no significant differences between any two groups of them ( P>0.05). Bland-Altman showed good consistency for all measurements within and between operators. Conclusions:The three modeling methods, including blood flow modeling, blood pool modeling and cavity modeling, have their own advantages in displaying different types of fetal heart malformations. Appropriate modeling methods should be selected for 3D modeling and printing to make up for the limitations of single modeling method. The consistency between measurements on 3D models and those on echocardiography is high, and the repeatability between operators is good.

Objective To explore the value of superior vena cava (SVC) Doppler spectrum in evaluation of the therapeutic effects of intermittent hypobaric hypoxia (HBHO)-induced pulmonary hypertension (PH) in rats and establish a new method for assessing pulmonary hypertension.Methods Fifty male SD rats were included.Forty of them were developed HBHO-PH and randomly divided into four groups with different manipulations:beraprost treatment group,sildenafil treatment group,placebo group and model group,with 10 rats in each group.The rest of 10 rats served as controls.Cardiac structure,pulmonary peak velocity (PAVmax),tricuspid peak velocity (TVEmax) and SVC Doppler ultrasound were performed in all rats before and after treatment for 2 weeks.Pulmonary arterial pressure was determined by the right heart catheterization.The relationship of the parameters with the pulmonary arterial pressure was analyzed.HE staining was done in lung tissues.Results Right heart catheterization showed that pulmonary artery systolic pressure (PASP) of the treatment groups were lower than that of the model group,the difference was significant(P ＜0.01).Pulmonary artery pressure decreased in varying degrees both after placed in a normal environment and after 2 weeks of treatment.PASP of the beraprost treatment group and the sildenafil treatment group decreased significantly and showed no statistical significant difference with the control group.In contrast,PASP of the placebo group was significant higher than that of control group(P ＜ 0.05).No statistically significant difference was found between the non-placebo treatment groups in PASP.Compared with the control group,the right ventricle/body weight ratio of the model group was statistically significant increased in all other groups(P ＜0.01).Right SVC AR/S ratio was well correlated with PASP (r =0.603,P =0.001).Right SVC AR/S ratio was statistically significant lower in treatment groups compared with the model group (P ＜0.01).All groups except the control group demonstrated various degrees of pulmonary arterial wall thickening.Conclusions The right SVC spectrum of AR/S correlates well with PASP and can be used to evaluate the pharmacological therapeutic effect of rats with HBHO-PH,in particular with moderate to severe PH.

Objective To explore the value of transthoracic echocardiographic suprasternal view in　the diagnosis of the subtype of the patent ductus arteriosus(PDA).Methods Sixty-five cases with PDA were examined by transthoracic echocardiographic suprasternal view and parasternal great artery short axis view respectively before closure therapy.The diameters of both the aotic and pulmonary side were detected,and subtype diagnoses were made.The results were compared with those from digital subtraction angiography (DSA).Results The demonstrated rates of PDA were 100％ on the parasternal great artery short axis and suprasternal views.Of the 65 cases,12 cases,19 cases and 19 cases were the funnel type of PDA checked on the parasternal great artery short axis view,suprasternal view and DSA respectively.The demonstrated rate of the parasternal great artery short axis view was lower than that of the suprasternal view (x2 =5.14,P ＜0.025 ).The diameter of the aotic side of PDA was (8.31 ± 2.76)mm,(10.87 ± 3.26) mm and (11.15±3.29)mm and the diameter of the pulmonary side of PDA was (5.69± 2.82)mm,(5.75 ± 2.63)mm and (6.09 ± 2.78) mm respectively on the above two views and DSA.Conclusions The diameter of the aotic side of PDA can be accurately detected by using superasternal view,which would be helpful for the diagnosis of PDA subtype.

Objective To investigate the clinical characteristics of laminar shelling decompression for the treatment of thoracic spinal stenosis.Methods One hundred and twenty-one patients with thoracic spinal stenosis were reviewed.Ages of these 51 male and 70 female patients ranged from 45 to 71 years (mean 54.8 years).There were 72 patients with thoracic ossification of ligamentum flavum(OLF),21 patients with thoracic ossification of posterior longimental ligament(OPLL)and 28 patients with thoracic OLF and OPLL.The lesion segmentum,kyphosis angle of thoracic vertebra and residual area of vertebral canal(RAVC)were measured.All these patients were treated with laminar shelling decompression.Preoperative and postoperative functional statuses were evaluated using a Japanese Orthopaedic Association(JOA)score.Results Thoracic OLF were found between T7 to T12 in 77.0% of the lesions;thoracic OPLL were found between T1 to T6 in 81.1% of the lesions.Of the 121 patients,the mean kyphosis angle was 31.5°±6.8° in upper thoracic spine and,9.4°±3.5° in lower thoracic spine.In patients whose RAVC were more than 80%,the pre- and postoperative mean JOA score was 7.7±1.4 and 9.5±1.6 respectively;RAVC more than 50%,5.2±1.8 and 8.6±2.1 respectively;RAVC less than 5%,4.8±1.4,and 5.6±1.3 respectively.Conclusion Thoracic OLF mostly occurred in lower thoracic spine,while thoracic OPLL mostly occurred in upper thoracic spine.The RAVC is a significant factor to the prognosis of thoracic spinal stenosis.As long as the clinical symptoms correspond with imaging findings,it is better to resect the whole ossification part as much as possible.Thoracic spinal stenosis often recurs after surgery.More attention to decompression ranges and decompression skills shoud be paied during revision surgery.

BACKGROUND: Previous studies demonstrated that recombinant human bone morphogenetic pretein-7 (hBMP-7) can effectively promote the synthesis of extracellular matrix, repair of damaged disc matrix, restore of degenerative disc height. It is hoped that BMP-7 can be used to control and reverse the intervertebral disc degeneration. However, because of the short half-life of recombinant protein and low biological activity, it is difficult to maintain BMP-7 high concentrations on degenerative disc. Gene therapy can prevent these defects effectively.OBJECTIVE: To study the effect of hBMP-7 gene transfeotion on biological activity of primary cultured rabbit nucleus pulposus cells in vitro, to determine the feasibility of hBMP-7 gene which will on gene therapy research of intervertebral disc degeneration,and to provide basis for further study.DESIGN, TIME AND SETTING: A randomized and controlled observation was performed at the Institute of Cardiothoracic Surgery of Changhai Hospital from December 2005 to September 2006.MATERIALS: Six healthy New Zealand white rabbits of either gender, averaging 4 weeks old and weighing 500 g, were used in this study, and Ad-hBMP7 was constructed by the Cardiothoracic Surgery Institute of Changhai Hospital.METHODS: After rabbits sacrifice under aseptic condition, the nucleus pulposus was got. After digested with Pronase, type Ⅱcollagenase and type Ⅱ DNAase (4 hours, 37 "(2), the cells were seeded in the Petri dishes and were kept in the incubator. After 7 days and then twice a week, the media were refreshed. The nucleus pulposus cells were infected by adenovirus integrated with hBMP7 gene. The cells which were transfected by adenovirus vector for Lac-Z gene and which were not transfected were adopted as control.MAIN OUTCOME MEASURES: The expression of hBMP-7 was determined by RTopCR and Western blot. The effect of hBMP-7 on cell proliferation was surveyed by MTT. Furthermore, the effect of hBMP-7 gene on synthesis of proteoglycan and type Ⅱcollagen was detected by modified dimethylmethylene blue method and ELISA, respectively.RESULTS: Gene sequencing and PCR showed that hBMP-7 gene was inserted correctly and no mutation happened. The pdmary cultured rabbit nucleus pulposus cells were identical with those reported in literature. After Ad-hBMP7 transduct into the nucleus pulposus cells, high level of hBMP-7 expression was observed and lasted over 3 weeks. Also hBMP-7 gene can promote cell proliferation and synthesis of proteoglycan and type II collagen with significant difference compared with control groups (P < 0.05).CONCLUSION: hBMP-7 gene mediated by adenovirus can be the target gene for the further study on gene therapy of intervertebral disc degeneration.

Objective To retrospectively analyse the anterior and posterior surgical approaches in treatment of unstable burst thoracolumbar fractures and compare radiographic measurement parameters of beth surgical techniques so as to provide references for surgical treatment of such kind of fracture. Methods The study selected 41 patients with unstable thoracolumbar fracture treated with either anterior neurodecomprossion and fixation (n=19) or posterior reposition and internal fixation by pedicle screw (n=22) from January 2003 to December 2005. All patients were followed up for 24-48 months ( mean 38 months) and divided into anterior approach group and posterior approach group. Sagittal alignment was assessed by the Cobb angle depending on lateral radiographs. Results The Cobb angle of the anterior approach group was average 27.3°on admission but 3.1°postoperatively and 4.6° at follow-up; while the Cobb angle of posterior approach was average 26.1° on admission, 3.0°postoperatively and 12.5°at follow-up. There was no statistical difference between Cobb angle on admission and postoperative one (P>0.05) but showed significant differences between them at follow-up ( P<0.01). Conclusion The anterior surgical approach can consistently yield better maintenance of kyphotic correction compared with the posterior surgical approach.

BACKGROUND: The establishment of animal models is of important significance for understanding the pathogenesis, prevention, and treatment of intervertebral disc degeneration. OBJECTIVE: To develop rabbit models of intervertebral disc degeneration by acupuncture and to analyze the effects of acupuncture on intervertebral disc height and degeneration by X-ray and MRI examinations. DESIGN: A randomized and controlled observation. SETTING: Department of Orthopaedics, Changhai Hospital, Second Military Medical University of Chinese PLA. MATERIALS: This study was performed at the Animal Cener, Changhai Hospital, Second Military Medical University of Chonese PLA between June 2005 and April 2006. Six healthy New Zealand white rabbits of either gender, averaging 6 months old, weighing 2.5 kg on average, were provided by Animal Cener, Changhai Hospital, Second Military Medical University of Chinese PLA [permission No. SCXK (hu) 2002-0006], and recruited for this study. The protocol was performed in accordance with ethical guidelines for the use and care of animals.METHODS: ① Operation was made in experimental rabbits via the anterior retroperitoneal approach. The management for the intervertebral discs was as follows: L3-4 was the control disc without exposure or needle stab; L4-5 was subjected to sham-operation with only exposure; L5-6 was the experimental disc with three times of anterior-lateral needle stab after exposure. Lumbar lateral X-ray film was respectively taken with a CR machine (Simens Company) prior to and 4 weeks after surgery for measuring L3-4, L4-5, and L5-6 intervertebral disc height and calculating the ratio with intervertebral disc height prior to surgery. Each segmental lumbar intervertebral disc T2-weighted signal was measured with a 1.5 T medical superconductive magnetic resonance scanner (Simens Avanto). According to signal intensity, intervertebral disc degeneration was graded: a score of 4 indicated normal intervertebral disc without apparent degeneration but with bright signal, a score of 3 indicated slight degeneration with a little decrease in T2-weighted signal, a score of 2 indicated moderate degeneration with apparent decrease in T2-weighted signal, and a score of 1 indicated severe degeneration with apparent decrease in both T2-weighted signal and intervertebral disc height. MAIN OUTCOME MEASURES: Intervertebral disc height change revealed by lumbar lateral X-ray film; Intervertebral disc degeneration degree analyzed through magnetic resonance imaging (MRI) examination. RESULTS: All 6 experimental rabbits were included in the final analysis. The postsurgery-to-presurgery ratio of intervertebral disc height was 0.982 5±0.017 08 and 0.972 5±0.017 08 for L3-4 and L4-5 respectively, which was higher compared to that for L5-6 (0.550 0±0.02 582). Significant statistical difference existed (P ＜ 0.01). T2-weighted singal score was (4.00±0.0) and (3.75±0.5) for L3-4 and L4-5 intervertebral disc, respectively, which was higher compared to that for L5-6 intervertebral disc. Significant statistical difference existed (P ＜ 0.01). CONCLUSION: After 4 weeks of acupuncture, intervertebral disc height is decreased and interterbral disc degeneration obviously appears.

AIM:In human being,the exposure of lumbar Intervertebral discs usually requires the anterior transperitoneal or lateral retroperitoneal approaches. To study the feasibility of retropedtoneal approach to the lumbar spine in the New Zealand white rabbits.METHODS: The experiment was carried out between April 2005 and April 2006 in the Animal Center of Changhai Hospital.Second Military Medical University of Chinese PLA.Thirty New Zealand white rabbits,aged 6 months old, of either gender, weighing 2.5 kg,provided by the Animal Center of Changhai Hospital,Second Military Medical University of Chinese PLA [permission No.SCXK (hu) 2002-0006],were used in this study.During the experiment,the management of animals corresponded to Animal Ethical Standard.This study was approved by the Experimental Animal Ethics Committee,Changhai Hospital,Second Military Medical University of Chinese PLA.Transperitoneal approach was used to exposure the lumbar spine of experimental rabbits. The skin was disassociated, and a blunt dissection was made backwardly along the juncture of the maximum back muscle and external oblique muscle of abdomen,and lumbar intervertebral disc was exposed gradually.Observation index:①Operative effect of exposure.②Postoperative general condition (food intake,urination and defecation,activity,incision healing and death or not).RESULTS: Thirty experimental rabbits were involved in the final analysis.①The operative effect of exposure:The dght retroperitoneal approach was chosen,with satisfactory anesthesia and excellent exposure of rabbit lateral lumbar spine. And the exposure was usually accomplished within 15 minutes, with Less bleeding and no retroperitoneal rupture. ②Postoperative general condition: All animals recovered their consciousnesses within about 1 hour. They were intravenously injected continuously for supplementing blood volume,and after that,they were raised in the separate cases and were allowed to move freeLy.On the day of operation.they were fasted and forbidden to access to water.Their appetites began to decrease on the postoperative 1 day.restored from the 3rd day postoperatively and restored to normal on the 40th day postoperatively.All animals survived until after 4 weeks.They could move freely,without paralysis occurred or incontinence. There was one experimental animal whose surgical Incision broke.Debridement and resuture were given, and its wound healed. In all the other animals, the surgical incision healed well.CONCLUSION: Retroperitoneal approach can give an excellent access to the lumbar spine with easy operation and less complications.

With deeper understanding for intervertebral disc degeneration,the development and clinical application of protocols in molecular biology,biological intervention in initial stage of intervertebral disc degeneration can retard even reverse the degeneration process. Gene therapy of intervertebral disc degeneration refers to the selection of animal models and gene carriers,application of target genes,etc. It is the key for gene therapy to build human-like animal model,select proper gene carrier and apply ideal target genes. Prior to clinical application,the safety and efficacy of gene therapy should be proved,thus many problems deserve further study.