BACKGROUND:C2 transpedicle screw fixation for Hangman fractures has been paid more attention due to reliability and no loss of physiological function.However,there are lacks of biomechanical evidences for indication treatment because the fixation is single segmental.OBJECTIVE:To investigate the biomechanical stability of C2 transpedicle screw fixation for Hangman fractures.DESIGN,TIME and SEITING:This was a contrast study which was performed at the General Key Laboratory of Biomechanics,First Military Medical University of Chinese PLA from May to August 2004.MATERIALS:AO-universal titanium alloy transpedicle screw of 18 25 mm in length and 3.5 mm in diameter was adopted in this study.Six fresh C1-C4 cervical vetebrae samples were ordiually made into type Ⅰ,ⅡA,and Ⅱ Hangman fracture models.METHODS:After transpedicle screw fixation.Hangman fracture models were measured by non-destroyed style with spinal anterior flexion/posterior extension,left/right lateral curvature,and left/right axial direction.Loading/unlonding circulation was performed three times during each testing.Kinematics indicators were measured on the 3rd circulation.MAIN OUTCOME MEASURES:Spinal motor images at zero load and maximal load were obtained with laser photoscanning(0.1% in precision),and the corresponding systematic software was adopted to calculate 3D range of movement.RESULTS:The relative stability of type Ⅰ Hangman fracture models after C2 transpedicle screw fixation was 100.62%(inflexion),96.91%(posterior extension),99.19%(lateral curvature),and 97.12%(rotation)as compared to control group (P＞0.05).The relative stability of type Ⅱ Hangman fracture models after C2 transpedicle screw fixation was 47.84%(inflexion),21.29%(posterior extension),65.98%(lateral curvature),and 41.69%(rotation)as compared to control group (P＜0.05).CONCLUSION:Biochemical evaluation suggests that type Ⅰ and Ⅱ A Hangman fractures do fit for C2 transpedicle screw fixation,and the fixation may generate well physiological fixation or stability.However,stability of type Ⅱ Hangman fracture is poor,so it is not suitably adopted single transpedicle screw fixation.

BACKGROUND: Decompression-internal fixation is needed in the treatment of atlantoaxial dislocation accompanying with spinal compression caused by cranium-neck junction area malformation and other diseases.Different internal fixation methods are chosen according to different conditions, including anterior atlantoaxial internal fixation, posterior atlantoaxial internal fixation or occipitocervical internal fixation. Transoralpharyngeal atlantoaxial plate internal fixation is a method for atlantoaxial anterior fixation. It is developed recently and used for difficult and complicated atlantoaxial dislocation induced by congenital disease, trauma or rheumatoid arthritis.OBJECTIVE: To probe into the clinical application of transoralpharyngeal atlantoaxial reduction plate system in the atlantoaxial dislocation caused by obsolete odontoid fracture.DESIGN: Single Sample observation SETTING: Department of Orthopaedics, Guangzhou General Hospital of Guangzhou Military Medical University of Chinese PLA PARTICIPANTS: Twelve patients with atlantoaxial dislocation caused by obsolete odontoid fracture were selected in the Department of Orthopaedics, General Hospital of Guangzhou Military Medical University of Chinese PLA from January 2003 to October 2005. Among them, 7 were male and 5 were female, they were aged 47 years on average ranging from 36 to 59 years. The mean injured time was 19 months ranging from 4.5 to 36 months; 6 patients were graded as C degree, 3 as D degree and 3 as E degree in Frank gradation.METHODS: Twelve obsolete odontoid fracture caused by atlantoaxial dislocation underwent transoralpharyngeal anterior decompression. Transoralpharyngeal atlantoaxial reduction plate system was used in reduction and fixation. Autogeneic ilium was implanted into bilateral articulatio atlantoepistrophica.MAIN OUTCOME MEASURES: ① Frank gradation of patients at the 4th week after operation. ② whether the internal fixation is loose or not after operationRESULTS: ①Frank gradation at the 4th week after operation: Among the 6 patients who were primarily graded as C degree, 4 patients improved to be E degree and 2 patients D degree; Three patients who were primarily graded as D degree all improved to be E degree; Patients who were primarily graded as E degree did not changed. ② Except for one patient who suffered dislocation again for loosening of screw caused by tumble, the other patients had firm fixation, ideal fusion and satisfying spinal decompression.CONCLUSION: Transoralpharyngeal atlantoaxial reduction plate system finishes atlantoaxial reduction and fixation once. It avoids conducting posterior fusion fixation operation after anterior decompression. It also avoids fetal injury for spinal cord caused by extreme atlantoaxial unsteadiness in the process of movement and turning over.

OBJECTIVETo investigate the pathogenic factors of human cytomegalovirus (HCMV) infections.

METHODSTotally 36 serum samples were obtained from early pregnant woman and examined with ELISA for anti-HCMV antibody IgG and IgM. After artificial abortion,chorionic villus and decidua were also examined with polymerase chain reaction (PCR) for HCMV-DNA. When the results of PCR were positive, pathological changes of these chorionic villus and decidua were analyzed.

RESULTSThe results showed that only 10 samples were PCR positive while IgG and/or IgM antibody to HCMV was positive. After infection with HCMV, different changes occurred in chorionic villus and decidual trophoblastic cells placental villus were hyperplasic and decidua cells degenerated and necrotized followed by lymphocytes infiltration.

CONCLUSIONThese pathological changes may be one of pathogenic factors of HCMV.

Adult ; Antibodies, Viral ; blood ; Chorionic Villi ; pathology ; virology ; Cytomegalovirus ; genetics ; immunology ; isolation & purification ; Cytomegalovirus Infections ; pathology ; DNA, Viral ; analysis ; Decidua ; pathology ; virology ; Female ; Humans ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Pregnancy ; Pregnancy Complications, Infectious ; pathology ; virology

OBJECTIVETo design a tool for evaluating the sound transmission function of ossicular prosthesis and explore the impacts of ossicular prosthesis bead area and the effects of the mass of ossicular prosthesis on the sound transmission function in mechanical middle ear model.

METHODSTwo latex membranes were used to represent the tympanic membrane and oval window membrane. The ossicular prosthesis was fitted between the artificial tympanic membrane and oval window membrane during the test. Pure tune signals were used to stimulate the vibration of tympanic membrane. The vibration of oval window membrane was recorded by a laser Doppler vibrometer. The ossicular transmission function was evaluated by comparing the vibration velocities of oval window membrane. Two groups of titanium ossicular prosthesis with different head area and mass respectively were fitted into a mechanical middle ear model to evaluate their sound transmission functions.

RESULTSThe feeling threshold curve of mechanical middle ear model (MMEM) was similar to the hearing threshold curve of normal person. The transmission function of the prosthesis with small head area was better than that of prostheses with large head area at frequencies 1500-4000 Hz. The small-massed prostheses functioned better at higher frequencies and the large-massed prostheses functioned better at lower frequencies. But small-massed prostheses functioned better as a whole.

CONCLUSIONSThe MMEM was an idea tool to evaluate the transmission functions of different ossicular prostheses. Both the head area and prosthesis mass had an influence on the transmission function of ossicular prosthesis. So while designing the ossicular prosthesis or performing ossiculoplasty, both the head area and prosthesis mass should he taken into consideration.

Acoustic Impedance Tests ; Acoustics ; Ear, Middle ; anatomy & histology ; Models, Anatomic ; Ossicular Prosthesis ; Prosthesis Design

Objective To evaluate the biomechanical characteristics and the clinical advantage of transoral atlantoaxial reduction plate(TARP)Ⅲ.Methods Design of TARP-Ⅲ was based on TARP-Ⅱ.The screw hole in the axis was moved 1-2 mm upwards and inwards in a plate which turned a vertebral screw into a pedicle screw or an articular process screw.A polyaxial self-lock ring and polyaxial guiding drill were added to the crew hole of the plate.Finally,the withdrawal resist ence force of the three axis screws was tested and TARP-Ⅲ was used in 44 patients with complicated irreducible atlantoaxial dislocation.The axis was fixed with the pedicle screw or the articular process screw.Results The maximum withdrawal resist ence force of the anterior pedicle screw,the articular process screw and the vertebral screw in the axis was(593.1 ± 97.8)N,(469.9 ± 73.3)N and(395.2 ± 75.1)N respectively,with statistical difference between groups among three fixation methods(P ＜ 0.05).All 44 patients were followed up for 5-38 months(average 18 months),which showed complete anatomic reduction in 36 patients and appropriate anatomic reduction in eight,with basic correction of the angles between the brain stem and the spinal cord and sufficient decompression of the spinal cord.The decompression rate of the cervical spinal cord was average 88.2% according to the Yin evaluating method of cervical cord decompression.The improvement rate of spinal cord function was average 76.6% according to Japanese Orthopaedic Association(JOA)score.Conclusion With the design of polyaxial self-lock mechanism,TARP-Ⅲ with the pedicle screw or the articular process screw surpasses TARP-Ⅱ with vertebral screw in aspect of biomechanics.

Objective To explore the relationship between immune and pathogenesis of amyotrophic lateral sclerosis (ALS) in the investigation of neurofilaments phosphorylation and ultrastructure features in spinal cord ventral horn motor neuron injury mediated by immune.Methods Using transmission electron microscope,we studied the uhrastructure features of abnormal accumulations of neurofilaments (NF) in motoneuron of the spinal cord ventral horn,and immunohistochemically investigated neurofilaments phosphorylation.Results Electron microscope found that there was abnormal accumulation of interwoven NFs in motor neuronal perikarya and proximal axons.Immunohistochemical study revealed that the SMI-32 immunoreactive positive neurons (12.00?1.05),compared with control (18.00?1.83),were reduced (P

Objective To develop a double antibody sandwich ELISA assay for quantitative determination of recombinant human interferon α1b.Methods Mouse monoclonal antibodies with different binding site on rIFN-α1b were screened to select optimized candidates as coating and HRP-labeled index antibodies respectively.And a double antibodies sandwich ELISA was assembled; the reliable lower detection limit,specificity,accuracy and reproducibility were evaluated and validated.Results The quantitative sandwich ELISA had a reliable lower detection limit of 10 ng/ml,with a liner detection range 10-100 ng/ml (R2 =0.992),variation coefficient inter-plates is less than 10％.Conclusion The developed sandwich ELISA was a sensitive and specific,accuracy and reproducibility method for quantitative determination of recombinant human interferon αt1b in final product.

BACKGROUNDCell-based vascular therapies of endothelial progenitor cells (EPCs) mediated neovascularization is still a novel but promising approach for the treatment of ischemic disease. The present study was designed to investigate the therapeutic potentials of human umbilical cord blood-derived EPCs (hUCB-EPCs) in rat with acute myocardial infarction.

METHODSHuman umbilical cord blood (hUCB) mononuclear cells were isolated using density gradient centrifugation from the fresh human umbilical cord in healthy delivery woman, and cultured in M199 medium for 7 days. The EPCs were identified by double-positive staining with 1, 1'-dioctadecyl-3, 3, 3', 3'-tetramethylindocarbocyanine percholorate-labeled acetylated low-density lipoprotein (Dil-Ac-LDL) and fluorescein isothiocyanate-conjugated Ulex europaeus lectin (FITC-UEA-l). The rat acute myocardial infarction model was established by the ligation of the left anterior descending artery. The hUCB-EPCs were intramyocardially injected into the peri-infarct area. Four weeks later, left ventricular function was assessed by a pressure-volume catheter. The average capillary density (CAD) was evaluated by anti-VIII immunohistochemistry staining to reflect the development of neovascularization at the peri-infarct area. The graft cells were identified by double immunofluorescence staining with human nuclear antigen (HNA) and CD31 antibody, representing human origin of EPCs and vascular endothelium, respectively. Expressions of cytokines, proliferating cell nuclear angigen (PCNA), platelet endothelial cell adhesion molecule (PECAM) and vascular endothelial growth factor (VEGF) were detected to investigate the underlying mechanisms of cell differentiation and revascularization.

RESULTSThe donor EPCs were detectable and integrated into the host myocardium as confirmed by double-positive immunofluorescence staining with HNA and CD31. And the anti-VIII staining demonstrated a higher degree of microvessel formation in EPCs transplanted rats, associated with a significant improvement of global heart function in terms of the increase of left ventricular end-systolic pressure (LVESP), +dp/dtmax and -dp/dtmax as well as the decrease of LVEDP in rats with EPCs therapy comparing to the control rats (P < 0.05). Moreover, the expression of the rat PCNA mRNA and PECAM were both enhanced in the EPCs group compared with that of the control group.

CONCLUSIONSThe human umbilical cord blood-derived EPCs could incorporate into new-born capillaries in rat myocardium, induce revascularization and improve the proliferation activity in the peri-infarct area, resulting in the improvement of global heart function. This may indicate a promising stem cell resource in cell-based therapy for ischaemic diseases.

Animals ; Cells, Cultured ; Cytokines ; metabolism ; Endothelial Cells ; cytology ; physiology ; Endothelium, Vascular ; Fluorescent Antibody Technique ; Humans ; Male ; Myocardial Infarction ; metabolism ; therapy ; Neovascularization, Physiologic ; physiology ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism ; Rats ; Rats, Wistar ; Stem Cell Transplantation ; Stem Cells ; cytology ; Umbilical Cord ; cytology ; Vascular Endothelial Growth Factor A ; metabolism

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD34 ; metabolism ; Child ; Colonic Neoplasms ; pathology ; Cystadenocarcinoma, Mucinous ; metabolism ; secondary ; Cystadenocarcinoma, Serous ; metabolism ; secondary ; Female ; Humans ; Macrophage Migration-Inhibitory Factors ; metabolism ; Microvessels ; pathology ; Middle Aged ; Neoplasm Recurrence, Local ; Ovarian Neoplasms ; metabolism ; pathology ; secondary ; Stomach Neoplasms ; pathology ; Tumor Suppressor Protein p53 ; metabolism ; Young Adult

OBJECTIVETo study the effect of valproate acid sodium(VPA) on apoptosis of human gastric cancer cell BGC-823 and to explore its possible mechanism.

METHODSCell growth inhibition was examined by MTT assay. Apoptosis rate was detected by FCM with Annexin V/PI staining. The activities and protein expression levels of caspase 3, caspase 8 and caspase 9 were examined by spectrophotometry and indirect immunofluorescence technique respectively.

RESULTSThe growth inhibition rate and apoptosis rate of human gastric cancer cells, treated with 0.75-4.00 mmol/L VPA for 24 h and 48 h, elevated in time- and dose-dependent manner. Apoptosis rates of VPA 0.75 mmol/L 24 h and 48 h were (7.2 +/- 0.5)% and (9.2 +/- 1.0)%, of VPA 4.00 mmol/L 24 h and 48 h were (16.7 +/- 2.2)% and (20.4 +/- 1.6)% respectively, which were significantly different as compared to the control [24 h, (4.9 +/- 0.2)%, 48 h, (5.1 +/- 0.8)%] (P< 0.001). The activities and protein expression levels of caspase 3 and caspase 9 were up-regulated compared with the control group (P< 0.001), meanwhile the activity and protein expression of caspase 8 enhanced slightly after VPA treatment for 48 h.

CONCLUSIONVPA can inhibit the growth and induce the apoptosis of BGC-823 cells mainly through the activation of caspase 9 pathway.

Apoptosis ; drug effects ; Caspases ; metabolism ; Cell Line, Tumor ; Humans ; Stomach Neoplasms ; pathology ; Valproic Acid ; pharmacology