In order to provide anatomical basis for transoral approach (TOA) in dealing with the ventro lesions of craniocervical junction, and the design and application of artificial atlanto-odontoid joint, microsurgical dissecting was performed on 8 fresh craniocervical specimens layer by layer through transoropharyngeal approach. The stratification of posterior pharyngeal wall, course of vertebral artery, adjacent relationship of atlas and axis and correlative anatomical parameters of replacement of artificial atlanto-odontoid joint were observed. Besides, 32 sets of atlanto-axial joint in adults' fresh bony specimens were measured with a digital caliper and a goniometer, including the width of bony window of anterior arch of atlas, the width of bony window of axis vertebra, the distance between superior and inferior two atlas screw inserting points, the distance between two axis screw inserting points etc. It was found that the width of atlas and axis which could be exposed were 40.2+/-3.5 mm and 39.3+/-3.7 mm respectively. The width and height of posterior pharyngeal wall which could be exposed were 40.1+/-5.2 mm and 50.2+/-4.6 mm respectively. The distance between superior and inferior two atlas screw inserting points was 28.0+/-2.9 mm and 24.0+/-3.5 mm respectively, and the distance of bilateral axis screw inserting points was 18.0+/-1.2 mm. The operative exposure position through TOA ranged from inferior part of the clivus to the superior part of the C3 vertebral body. Posterior pharyngeal wall consisted of 5 layers and two interspaces: mucosa, submucosa, superficial muscular layer, anterior fascia of vertebrae, anterior muscular layer of vertebrae and posterior interspace of pharynx, anterior interspace of vertebrae. This study revealed that it had the advantages of short operative distance, good exposure and sufficient decompression in dealing with the ventro lesions from the upper cervical to the lower clivus through the TOA. The replacement of artificial atlanto-odontoid joint is suitable and feasible. The design of artificial atlanto-odontoid joint should be based on the above data.
Atlanto-Axial Joint/*anatomy & histology ; Atlanto-Axial Joint/*surgery ; Bone Plates ; Bone Screws ; Cadaver ; Cervical Vertebrae/*anatomy & histology ; Cervical Vertebrae/surgery ; Equipment Design ; Internal Fixators ; Joint Prosthesis ; Models, Anatomic ; Odontoid Process/*surgery ; Prosthesis Design

Aim To establish experimental colitis model in Balb/c mice by Trinitrobenzene Sulfonic Acid (TNBS) enema. Methods Several doses of TNBS instilled into mice colon induced experimental colitis, then mortality rates of mice were observed. Severity of colitis was evaluated by the Disease Activity Index (DAI),Morphologic and Histologic analysis and Myeloperoxidase (MPO) analysis. We also observed the T cell proliferation of spleen. Results It showed that the mice mortality rate was increased when the mice were given the higher dose of TNBS. Most survived mice showed chronic inflammation in reduction colon. Histological examinations of the colon showed multiple erosive lesions and inflammatory cell infiltration composed of macrophages, lymphocytes, neutrophils in lamina propria and beyond mucosal layer. Some colon showed crypt distortion or reduction and high vascular density. Conclusion A TNBS dose of 1.5mg for each mouse was chosen for an appropriate experimental dose since the group showed less mortality rate and appropriate experimental colitis.

OBJECTIVETo study the distribution and antibiotic resistance of the isolated pathogens from children with infectious diarrhea in Guangzhou.

METHODSThe fecal samples of 2 409 children with infectious diarrhea between January 2006 and December 2007 were collected and cultured. Pathogenic bacterium were isolated and identified by biochemical and serological methods. The antibiotic susceptibilities were tested by the Kirby-Bauer method.

RESULTSA total of 448 isolates of pathogenic bacterium (18.6%) were obtained, including Shigella (n=159), enteropathogenic Escherichia coli (n=141), Salmonella (n=76), Vibrion (n=11), fungus (n=41), and C jejuni (n=20). All of isolates of the three major pathogenic bacterium, Shigella, enteropathogenic Escherichia coli and Salmonella, were susceptible to imipenem and less than 10% of the isolates were resistant to the third generation cephalosporins and beta-lactamase inhibitors. However, the isolates showed a high resistance to ampicillin and sulfamethoxazole/trimethoprim (>75%).

CONCLUSIONSShigella, enteropathogenic Escherichia coli and Salmonella were major pathogenic bacterium of diarrhea in children from Guangzhou. The major isolates were susceptible to imipenem, the third generation cephalosporins and beta -lactamase inhibitors, but were resistant to ampicillin and sulfamethoxazole/trimethoprim.

Adolescent ; Bacteria ; drug effects ; isolation & purification ; Child ; Child, Preschool ; Diarrhea ; drug therapy ; microbiology ; Drug Resistance, Microbial ; Female ; Fungi ; drug effects ; isolation & purification ; Humans ; Infant ; Male

Objective To investigate the effect of protein phosphatase 5 (PP5) on lipid metabolism in the PP5 knockout (KO) mice.Methods Male PP5 KO and wild type (WT) mice at the age of 6 weeks were used in this study. In order to study the effect of high fat diet ( HFD) feeding, the body weight was measured.The liver histology was examined by HE and oil red O staining.To further verify PP5 functions in the adipogenesis, in vitro experiment was carried out using mouse embryonic fibroblasts (MEF).Western blotting and real-time PCR were performed to quantified the expression of lipid metabolism-related genes in the liver tissues.Results Compared with the WT mice, the body weight gain was slower in the KO mice.The size of the lipid droplets was smaller and the quantity was less in the KO mouse liver tissue.In vitro study revealed that the KO mouse MEF cells showed less differentiated adipocytes with smaller lipid droplets than the WT MEF cells.This observation was further confirmed by detecting the expression of adipogenesis-related genes in the HFD liver.The markers of adipocyte differentiation, such as CD36, AP2, PPARγ2, and Glut4, were significantly decreased, while energy expenditure-related markers, such as phosphorylation of GR and expression of UCP1, were significantly increased.Conclusions Protein phosphatase 5 may play a regulatory role in the mouse lipid metabolism through regulating the de-phosphorylation of p-GR and enhancing the expression of UCP1.

Objective To compare volumetric‐modulated arc therapy(VMAT) with intensity‐modulated radiation therapy (IMRT) for brain metastases with regard to the dosimetric character .Methods Sixty patients who were diagnosed with brain me‐tastases were included in this study .The target area received two dose levels using late addition amount technique ,WBRT (30 Gy/10 F) with following addition (20 Gy/10 F) to 59 Gy .For a fair comparison ,VMAT and IMRT treatment plans were respectively designed for every patient with the same dosimetric constraints .Dosimetric comparisons between VMAT and IMRT plans were ana‐lyzed to evaluate :target coverage and homogeneity ,conformity of PTV ;sparing of OARs ;monitor units (MUs) .Results Two treatment plans all reached the treatment need .When compared with IMRT ,there was no significant difference in Dmean of eyeball , len ,optic never ,visual chiasma ,parotid ,brain stem ,and external auditory canal of VMAT (P>0 .05) .The Dmax of eyeball ,len ,pa‐rotid ,and external auditory canal of VMAT were lower than that in IMRT group (P<0 .05) .The VMAT group has the less MUs (P=0 .017) and less treatment time .Conclusion VMAT can reach the big‐dose radiotherapy need on brain metastases clinically . There are no significant diffference between VMAT and IMRT on Dmax ,Dmean ,CI ,and HI .The Dmax of eyeball ,len ,parotid ,and external auditory canal of VMAT were lower than that in IMRT group .The VMAT can reduce the radiotherapy time .

OBJECTIVETo compare the difference of stress distribution among models with different fiber frameworks.

METHODSFour models were generated in Marc 2003 software. Four types of loads simulating normal mastication were selected. The stress within models was calculated, and output by means of graph and data.

RESULTSThere was stress concentration around connectors and retainers near connectors under cusp -fossa load, occlusal even load, and lateral load. When dentures were reinforced with fiber framework, area of stress concentration and principal stress max could decrease in comparison with pure composite resin bonded fixed partial denture. Under buccal-lingual load, there was another stress concentration around central fossa beside above two stress concentration areas. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce principal stress under buccal-lingual cusp loads.

CONCLUSIONUnder 4 types of loads simulating normal mastication, three critical regions were disclosed at the area of retainers adjacent connectors, connectors and occlusal central fossa and fissures. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce stress concentration under buccal-lingual cusp loads.

Composite Resins ; Denture Design ; Denture, Partial, Fixed, Resin-Bonded ; Glass

Objective To explore the role of transvertebral transposition of the spinal cord in the treatment of the pa?tients suffering from angular kyphoscoliosis with neurologic deficit. Methods Twelve patients with at least 1 year follow?up, in?cluding 5 females and 7 males, suffering from neurologic deficit secondary to angular kyphoscoliosis underwent transvertebral transposition of the spinal cord and posterior correction from January 2005 to June 2013 were retrospectively analyzed. The initial age averaged 21±14 years. The etiologies of deformity were congenital kyphoscoliosis in 9 patients, idiopathic kyphoscoliosis in 3 patients. Preoperative spinal cord function graded by Frankel criteria was 3 cases of grade C and 9 of grade D. The initial major curve was 79.4°±16.2° with a global kyphosis of 68.3°±25.0°. The change of distance between spinal cord and canal on the convex side at the apex was measured on MR images to evaluate the efficacy of transposition;in addition, Cobb angle on coronal and sagit?tal plane was evaluated before surgery, on discharge and at the last follow?up. Results All patients were followed up for 2 years on average (1-5 years). The post operation spinal function evaluated by Frankel criteria were as follow:with grade C of 1 case, grade D of 4 cases and grade E of 7 (7 cases changed one grade, 1 case changed two grades, 4 cases did not change obvious). At the last follow?up, all the cases got obvious recovery of spinal function, with 1 case of grade C and 11 of grade D (10 cases changed one grade, 2 cases changed two grades). The distance between spinal cord and canal on the convex side at the apex changed from 11.9±6.4 mm to 9.8±6.9 mm. After surgery, the major curve improved to 39.3°±15.1° with 50.3%±20.5%correction rate, and the mean loss of correction was 6.1%±7.5%. The mean kyphosis was 41.3°±16.6°, demonstrating a 39.0%±13.0%correction rate im?mediately after operation, and showing 3.1%±4.2%correction loss at the final follow?up. No neurologic complications or no death occurred intra?and post?operatively. No screw or rod fracture, instrumentation loosening and pseudarthrosis were found during fol?low?up. Conclusion Transvertebral transposition of the spinal cord and posterior correction is a useful procedure for the recovery of neurologic deficit secondary to angular kyphoscoliosis, with good results of deformity correction.

OBJECTIVETo analyze influence of fiber framework design on fracture strength of posterior glass fiber-reinforced-composite resin-bonded fixed partial dentures (GFRC-RBFPD).

METHODSBased on established three-dimensional finite element models of GFRC-RBFPD for restoring the second mandibular premolar or the first mandibular molar, traditional fiber framework design and modified fiber framework design were analyzed. Two types of load, including cusp-fossa load and buccal-lingual cusp load, were selected. Load values were 400 N on premolar and 600 N on molar respectively. The fracture strength of GFRC-RBFPD was calculated.

RESULTSUnder cusp-fossa load, the fracture strength was 1340 N for both types of fiber frameworks of premolar GFRC-RBFPD, and 864 N for traditional framework and 875 N for modified framework of molar GFRC-RBFPD. Under buccal-lingual load, the fracture strength of premolar GFRC-RBFPD was 792 N for traditional framework and 1019 N for modified framework; that of molar GFRC-RBFPD was 645 N for traditional framework and 652 N for modified framework.

CONCLUSIONSThe modified fiber framework obviously improved the strength of premolar GFRC-RBFPD and only slightly improved that of molar GFRC-RBFPD.

Dental Prosthesis Design ; methods ; Dental Stress Analysis ; Denture, Partial, Fixed, Resin-Bonded ; Finite Element Analysis ; Glass ; Humans ; Molar

Orjective:To obtain recombinant CHO-K1 with expressing sPDGFR? and to identify the biological activities of sPDGFR? secreted in non-serum medium.Methods:Recombinant human sPDGFR? expression vector pIRES-Neo3-sPDGFR?-Fc was constructed and then transfected into CHO-K1 cells by using LipofectamineTM 2000.After screened with G418 in 8 weeks,some monoclone cells were selected randomly to amplify in 96-well-plate to 24-well-plates,and then to identify positive cell clones by RT-PCR.Furthermore,the candidate cell clones were test by Real-Time PCR and Western blot assays.Finally,anti-proliferation activities of the expressed sPDGFR? were analyzed by MTT.Results:sPDGFR?-Fc was cloned into pIRES-Neo3 correctly.The sPDGFR?-Fc expression level in recombinant CHO-K1 cell clones were concordant in between Realtime PCR and Western blot assay.sPDGFR?-Fc obtained from cultured non-serum medium of positive CHO-K1 could significantly inhibit proliferation of vascular endothelial cell.Conclusion:Successed to select recombinant CHO-K1 cell lines with high expressed sPDGFR?-Fc.The sPDGFR?-Fc can inhibit the cell proliferation significantly and it means sPDGFR?-Fc might be a new anti-cancer drug in the future.

Objective:To produce rhBMP-4 with bioactivity in E.coli. Methods: The full-length human BMP-4 gene was mutated by PCR without changes in amino acid sequence, then the synthesized gene was cloned into plasmid pET-3c, transducted into BL21(DE)plysS, and induced by adding IPTG to a final concentration of 1.0 mmol/L. The protein product was purified using ion-exchange chromatography method and then renaturated, bioactivity was checked by C2C12 differentiation in vitro and mouse ectopic bone formation in vivo. Results: A 438 bp gene fragment encoding mature peptide of hBMP-4 was cloned , the protein product was mostly in the form of inclusion body, after renaturation, the engineering protein shows better bioactivity. Conclusion:The mutant strategy can enhance the expression of bioactive rhBMP-4 in E.coli expression system.