Ultrastructural changes of the inner cell mass (ICM) in rabbit blastocysts from 4 to 7 days post coitum (p.c.) were observed with transmission electron microscope. It revealed that ICM of blastocyst on day 5 p.c. began to differentiate after they were arranged into a single layer, and under which the primitive endoderm appeared. It is suggested that the primitive endodermal cells in rabbit blastocysts are derived from the scattered ICM-like cells at the inner surface of the mural trophoblast rather than delaminated from ICM proper. In this paper, disruption and disappearance of polar trophoblast are described and discussed.

[Objective]To explore the optimal time for the surgical operation on patients with ossification of the posterior longitudinal ligament of the cervical spine. [Methods]The clinical symptoms,the persistent time of the symptoms and the interval from exacerbation to operation in 168 patients with OPLL were analyzed.[Results]The average time was 27.6 months from the onset of myelopathy to the operation on patients with OPLL,and 17.4 months from the decrease of muscle strength in extremities to the operation,and 5.3 months from the symptomatic exacerbation of the extremities especially the decrease of muscle strength in lower extremities to the operation.[Conclusion]The patient should be treated earlier by surgical operation after his/her illness has been diagnozed as OPLL.It is the optimal time for surgical operation when the patient has imaging change of hypertrophy or ossification of the posterior longitudinal ligament and severe compression of spinal cord(more than 60% spinal canal stenosis),or the decrease of muscle strength in extremities especially in lower extremities.

The forced oscillation technique (FOT) is a noninvasive method for respiratory mechanics measurement. For the FOT, external signals (e.g. forced oscillations around 4-40 Hz) are used to drive the respiratory system, and the mechanical characteristic of the respiratory system can be determined with the linear system identification theory. Thus, respiratory mechanical properties and components at different frequency and location of the airway can be explored by specifically developed forcing waveforms. In this paper, the theory, methodology and clinical application of the FOT is reviewed, including measure ment theory, driving signals, models of respiratory system, algorithm for impedance identification, and requirement on apparatus. Finally, the future development of this technique is also discussed.
Algorithms ; Electric Impedance ; Oscillometry ; Physical Therapy Modalities ; Respiratory Mechanics

BACKGROUND: It is difficult to conduct the operation of ossification of ligamentum flavum (OLF) in thoracic spine, and the operation needs complecated operative skill, and unmerited disposal tends to worsen neurological dysfunction.OBJECTIVE: To analyze the operative method for OLF of thoracic spineand functional restoration.DESIGN: Case analysis.SETTING: Department of Orthopaedics, Changzheng Hospital, SecondMilitary Medical University of Chinese PLA.PARTICIPANTS: Totally 56 patients with OLF of thoracic spine, whowere treated at the Department of Orthopaedics, Changzheng Hospital fromAugust 1996 to August 2003.METHODS: The operative therapy was performed in all the patients, and the method was determined by the results of MRI and CT examination: ①The 19 patients, whose OLF in thoracic spine was focal type, and range of lesion did not exceed two segments, were treated with simple resection and decompres sion in posterior wall of vertebral canal. ②Fenestration and sledging-allocating manipulation in the whole piece unilateral lamina of vertebra were carried out in 29 cases involving more than 2 segments. ③If coplanar OLF in thoracic spine combined with protrusion of thoracic spine disc or ossification of posterior longitudinal ligament, decompression of posterior midline approach+posterior lateral approach was performed, totally 8 cases.MAIN OUTCOME MEASURES: Post-operation functional restoration was evaluated with Epstein standard, excellent: recovery of sensation and exercise was near to normal; good: spinal cord function was improved significantly, and permitted to walk with brace; fair: small partial restoration of sensory and motor function, unable to walk; bad: Inefficiency or becoming severe.RESULTS: A total of 55 cases were followed up for more than one year and 1 case only for two months after operation. ①Functional restoration: excellent: 39 cases; good: 8 cases; fair: 5 cases; bad: 4 cases. ②Symptom recovery after operation was confirmed by disappearance of tight sensation, reduction of muscular tension, relieving of numbness in order. ③The recovery was rapid for 3 to 6 months after operation. Part of patients' condition was still ameliorating during one year after operation, and rare advancement 2 years later. The recovery of complete paraplegics was bad, so was the severe paraplegia with long history. CONCLUSION: Compressive myelopathy caused by OLF in thoracic spine should be treated in an earlier period by operation. Resection and decompression of posterior wall of thoracic spine and decompression of posterior approach could be choosed according to different condition.

Objectives To explore the humoral immunologic mechanisms of the susceptibility to invasive pneumococcal diseases (IPD) in asthmatic children. Methods Plasma samples were collected from 43 asthmatic and 20 non-asthmatic chil-dren. Anit-pneumococcal capsular polysaccharide (PPS)-IgG concentrations were measured by enzyme-linked immunosorbent assays. Results The mean concentrations of anti-PPS 14, 19A and 23F-IgG were signiifcantly higher in asthmatic children than in non-asthmatic children (P<0.05). The ratios of the asthmatic children who had anti-PPS 14, 19A and 23F-IgG concentrations higher than the protective antibody level (≥0.2 μg/ml ) were 100%for all the serotypes. Conclusions The immune responses of producing anti-PPS IgG to defense IPD were normal in asthmatic children. Asthmatic children may be more susceptive to pneumococcal infection or colonization than non-asthmatic children.

Objective To explore the distribution and localization of LPGDS (Lipocalin-type prostaglandin D synthase) in rat testis and epididymidis and gain further insight into LPGDS potential function in male reproduction. Methods The expression of LPGDS in rat testis and epididymidis was assessed using RT-PCR and immunobloting. Using immunohistochemistry to explore the distribution of LPGDS in rat testis and epididymidis. Results None of the LPGDS studied was present in the testis of 2 month old SD rat. LPGDS was strikingly expressed in the caput epididymidis, while moderate to weak expressing was observed in the corpus and cauda epididymidis. The result of immunohistochemistry displayed that LPGDS was mainly localized within the cytoplasm and the cilia of the epithelial cells in rat epididymidis. Conclusion LPGDS was mainly distributed in epididymidis and localized with in the cytoplasm and the cilia of the epithelial cells. There was no LPGDS expressed in the testis of 2 month old SD rat, but it was strikingly expressed in the epididymidis, and the dose of expression was different, which suggested that LPGDS may play some kind of role during the process of the spermatozoa maturation.

Orthopaedic surgery is a fast developing subject in clinical surgery.Based on the characteristics of the orthopaedic surgery and aiming to enhance the medical students’practical ability of basic skills and clinical thinking we adopt the explorative clinical teaching which can be helpful to training students’initiative of finding and working out a solution by themselves and cultivating their capability of innovation and creation.

Community-based rehabilitation (CBR) is positioned to provide various strategies for people with disabilities for achieving the embracing development of the community. CBR is also the terminal of the three-level rehabilitation service system. This paper analyzed the status of domestic community-based rehabilitation based on the document, discussed the possible problems referred to the international concepts about CBR, and suggested a new service pattern of CBR based on the internet and information technology.

Objective To review the relevant causes for and treatment of nerve injuries in the anterior cervical surgery. Methods From January 2008 to December 2009,859 cages of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma were treated by anterior cervical surgery.This study retrospectively analyzed the clinical data of seven cases who were with worsened symptoms of spinal cord injury and related nerve injury. Results Of 859 cases,five cases(0.58%)were with spinal cord injury,one(0.12%)with recurrent laryngeal nerve injury and one (0.12%)with laryngeal nerve injury.Hematoma occurred in four cases after surgery caused spinal cord injury and all the four patients recovered to normal after removal of the hematoma and timely treatment with mythylprednisolone and hyperbaric oxygen.Cervical spine trauma was worsened in one patient after the anterior cervical surgery.The patient restored to its original level of spinal cord gradually through some measures such as tracheotomy,ventilator support,hormone therapy and hyperbaric oxygen treatment.Laryngeal nerve injuries in two cases recovered to normal after conservative treatment with hormone,dehydration and other drugs within three months after surgery. Conclusions Anterior cervical surgery of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma are likely to induce the related nerve damage.The good prognosis can be obtained under timely prevention and treatment.

BACKGROUND: Ossification of intervertebral disc, and ossification of spinal ligament and fibrous tissues are still uncertain.OBJECTIVE: To observe osteogenic potential of fibrous ring in the cervical intervertebral disc during bone fusion.DESIGN, TIME AND SETTING: The comparative observation was performed at the Experimental Animal Center of Second Military Medical University and Shanghai Institute of Orthopedics in October 2006.MATERIALS: Ten healthy goats, including 6 males and 4 females; titanium alloy cervical hollow threaded columnar internal fixator (CHTF) for goat, simulated human used internal fixator by Kanghui Medical Innovation Co., Ltd., Changzhou.METHODS: Every goat underwent conventional anterior cervical decompression and internal fixation. Two adjacent intervertebral spaces among C2-6 were selected and implanted with 2 CHTFs for each space. Of the 4 CHTFs, 3 were filled with cancellous bone alone, cancellous bone plus fibrous ring, and fibrous ring alone, respectively; the other one filled with nothing served as blank control.MAIN OUTCOME MEASURES: Implant location and fusion condition on anteroposterior and lateral radiographs and CT plain scanning at 6 and 12 weeks postoperatively; bone graft fusion and regional tissue reaction by histology.RESULTS: Radiographs and CT showed that CHTF was in the position during the whole experimental procedure with no loosening, displacement or dislocation. At 6 weeks, bone tissue was found surrounding CHTF and the vertebral body, and bone bridge formed in the connection site of CHTF and the vertebral body. New cartilage and bone trabecula formation were found in the CHTF filled with cancellous bone alone, accompanied by necrotic original bone graft; in the CHTF filled with cancellous bone and fibrous ring, necrotic fibrous tissue and newly formed cartilage accumulation surrounding original bone trabecula and fibrous ring were found; 6 weeks after surgery, there were fibrocartilage in fibrous tissue of CHTF filled with fibrous ring alone, and at 12 weeks postoperatively, newly formed cartilage was observed. In blank control group, only few newly formed cartilages were found at 12 weeks postoperatively. CONCLUSION: Enchondral ossification of fibroblast may be the osteogenic pattern of fibrous ring of cervical intervertebral disc.