BACKGROUND: Segmental defect of mandible is often caused by tumor, trauma and other reasons. Simultaneous mandibular defect by vascularized fibular flap is the most important repair method at present. It is not only useful for the reconstruction with titanium plates, but also useful for small titanium plates for fixation. Clinical retrospective studies have shown that there is no significant difference in postoperative complication rate between patients with the two fixation methods, but relevant biomechanics studies are still lacking at present. OBJECTIVE: The three-dimensional finite element analysis was used to analyze the stress distribution and stability on mandibular segmental defects simulated fibular flaps grafted with reconstruction plates and miniplates fixation. METHODS: A healthy adult male with complete dentition was selected for CT scan and data were input into the computer to reconstruct the mandible and dentition model. Three types of 3D models were built for mandibular defects dependent on Jewer’s classification, including models H (loss of lateral mandible, mandibular angle, ascending branch of mandible, and condyles), L (loss of unilateral mandible) and C (loss of bilateral mandible chin). Mechanical distribution features and stability of fixation with reconstruction plates and miniplates were comparatively studied after fibular repair of mandibular segmental defects. RESULTS AND CONCLUSION: (1) The stress graphs showed that stress was mostly higher in surrounding areas of normal mandibles such as condyle, condylar neck, mandibular angle, molar and titanium screws. In particular, the stress was highest near mandibular angles. (2) For type-H defect, the great stress was generated near the mandibular angles when mandible was reconstructed with reconstruction plate, and the stress value was 185 MPa. The stress values approximately ranged from 117 to 135 MPa on type-H and type-L defects with miniplates. The maximum stress of fibula block was less than 30.4 MPa, and the maximum stress of titanium nail was 56.2 MPa. (3) The relative displacements approximately varied between 15 µm and 18 µm on the fracture sides after repair with type-H and type-L defects with miniplates and reconstruction plates. Almost no relative displacement was generated on the fracture sides after type-C mandibular defects. (4) Both titanium reconstruction plates and titanium miniplates could meet biomechanical requirements for fibular repair of H, C, and L defects.

OBJECTIVEThis study aims to assess and compare the prevalence of Porphyromonas endodontalis (P. endodontalis) in root canals associated with primary and secondary endodontic infections by using 16s rDNA PCR and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR).

METHODSA total of 120 adult patients with one radiographically documented periapical lesion were included. Sixty teeth presented with primary endodontic infections and 60 with secondary endodontic infections requiring retreatment. P. endodontalis was identified by using 16s rDNA PCR techniques. The positive DNA expression of P. endodontalis in two types of infected root canals were quantitatively compared by using SYBR GREEN I RTFQ-PCR.

RESULTSThe prevalence of P. endodontalis in the root canals with primary endodontic infections was significantly higher than that in root canals with secondary endodontic infections (P = 0.001). However, RTFQ-PCR results showed no significant difference in DNA expression quantities between the primary and secondary endodontic infections root canals (P = 0.303).

CONCLUSIONP. endodontalis is more highly associated with root canals having primary endodontic infections, although P. endodontalis colonize in both root canals with primary and secondary chronic apical periodontitis.

Adult ; DNA, Bacterial ; Dental Pulp Cavity ; Gram-Negative Bacterial Infections ; Humans ; Polymerase Chain Reaction ; Porphyromonas endodontalis ; Retreatment

Adenocarcinoma ; metabolism ; pathology ; Adenocarcinoma, Mucinous ; metabolism ; pathology ; Adult ; Aged ; Aged, 80 and over ; Carcinoma, Signet Ring Cell ; metabolism ; pathology ; Erythropoietin ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Immunohistochemistry ; Lymphatic Metastasis ; Microvessels ; chemistry ; pathology ; Middle Aged ; Stomach ; chemistry ; pathology ; Stomach Neoplasms ; metabolism ; pathology ; Tissue Array Analysis ; methods

Acupuncture Points ; Adolescent ; Adult ; Aged ; Asthma ; therapy ; Combined Modality Therapy ; Electroacupuncture ; Female ; Humans ; Male ; Middle Aged ; Moxibustion ; Treatment Outcome ; Young Adult

Based on the gene sequence of AIV matrix protein 2(M2) and two cytotoxic T-lymphocyte epitopes derived from nucleoprotein,the prokaryotic expression vector pET-3M2e-NP1-NP2 was constructed.The target gene was expressed in the solvable form in BL21(DE3) when induced with 1.0 mmol/L IPTG and Western blot analysis showed that the expression product had good immunogencity.Purified fusion protein was mixed with various amount of adjuvant,including Freund's,Vash oil and chitosan,and then immunized 20-day-old chicken by intramuscular injection and boosted 3weeks later.Blood samples were collected weekly following the primary vaccination.The anti-M2e antibody was detected with ELISA method with the synthesized peptide as coated antigen;the neutralizing ability of anti-serum was evaluated on MDCK cell line and chick embryo,the CD4+ and CD8+ T lymphocyte amounts in peripheral blood of immunized chicken was measured by flow cytometry.Results showed that the fusion protein can induce immunological reaction,and the antibody can bind with the viral M2 protein that expressed on the surface of MDCK cells.Flow cytometry result showed that CD4+ and CD8+ T lymphocyte in peripheral blood increased obviously following immunization(P

Background and purpose:Ara-C is one of the most effective and common agents in the treatment of acute nonlyphocytic leukemia. Telomerase is a unique complex of ribonucleoprotein. It plays an important role in the pathogenesis and development of cancer. In this study, we investigate the changes of mRNA expression of telomerase subunits in HL-60 cells induced by Ara-c and try to come up with a theory that could help to assess the efficacy of Ara-C. Methods:The combinations of various Ara-C concentration and the incubation time were used to treat HL-60. The ratios of apoptotic cell to necrosis cell were determined by flow cytometry and the expressions of telomerase subunits mRNA were evaluated by RT-PCR.Results:① There was no influence on transcription of telomerase subunits gene after HL-60 cells was cultured with 0~0.2ug/ml Ara-C for 12 hours;② 2ug/ml and 10ug/ml of Ara-C could down regulate the expression of hTERT from 0.80+0.07 to 0.50+0.04 and 0.39+0.03, not hTR and hTP1;③ with longer incubation with 10ug/ml of Ara-C, the percentage of apoptosis could be increased. The maximal induction of apoptosis (18.16+4.25%) could be reached at 12hrs treatment of Ara-C, then gradually decreased later on. The rate of necrosis increased with time, the maximal percentage(57.94+12.03%) of necrosis was observed at 48hrs of incubation time with drug. The mRNA level of hTERT gene also decreased along with the cultured time , the lowest value (0.18+0.03) has been documented at 48hrs time point, but not hTR、TP1.Conclusions:① Ara-C could down-regulate the expression of hTERT mRNA in a dose-and time-dependent manner, but not hTR、hTP1;② There might be no relationship between the percentage of apoptosis induced by Ara-C apoptosis and the expression of telomerase hTERT gene mRNA, but a close relationship between necrosis and the expression of hTERT mRNA has been found.

Objective To investigate the expression in the VEGF,TGF-?1 of cervical squamous car- cinoma infected by HPV16,18.Methods Cells exfoliated from cervix(collected by clinician)of 99 women with cervical cancer and 54 women as a control group were analyzed blindly by human papillomavirus type 16 and 18 Fluorescent Polymerase Reaction Diagnositic kit.The expression of VEGF,TGF-?1 of the positive HPV16,18 of 38 women with cervical squamous cancer were studied by immunohistochemical stain.Results The positive expression of HPV16,18 was observed in 53 in the case of cervical cancer with positive rates of 54 %,but the positive rates was 7 % in the control group(P

Aim To investigate the age-related changes of TrkB mRNA in hippocampal formation of aged rats,and the effects of ginsenosides(GS),and provide reliable experimental evidence for anti-aging.Methods 24 Wistar female rats were randomly divided into 3 groups: Young,aged and GS group(fed with GS from 17 to 27 months).In situ hybridization(ISH) method was applied into qualifying and quantitating the TrkB mRNA expression in hippocampal formation.Results TrkB mRNA expression in aged CA3,CA1 and dentate gyrus decreased by 24.2%,13.4% and 50.6%(P

Objective To improve the knowledge and diagnostic ability of imagiology on neonatal respiratory distress syndrome (NRDS) computed radiograph(CR).Methods The doubtful patients were done to photographs bedside using the high resolution imaging plate, 50 cases of newborn with NRDS were selected whose clinical diagnosed clearly and had been treated and had the complete CR image documents.The CR change and clinical characteristics were observed dynamically.Results Nine of 50 cases were combined with aspirated pneumonia,8 cases with infective pneumonia,3 cases with intra-alveolar hemorrage,and 2 cases with pneumothorax.Accoding to X-ray manifestations,all cases were divided into four stages:Ⅰ stage(n=5), Ⅱ stage(n=20),Ⅲ stage(n=22),Ⅳstage(n=3).Typical CR signs included:the pulmonary lucency decreasd,wide-ranging net and grain shadowes of high density, and in companing with a lot of air brunchus sing.Conclusions Computed radiography is the most important imaging method in diagnosis of NRDS bedside ,and shall be improved the ability of diagnosis and differential of NRDS combined with the clinic.

OBJECTIVETo establish a PCR-based neutralization assay of hepatitis B virus (HBV), which may be applied for detecting neutralizing antibodies against HBV and used as an in vitro model to screen new HBV vaccines.

METHODSImmune serum was mixed with HBV stock. The mixture was incubated and then inoculated onto Hep G2 cell monolayers. After adsorption, washing and incubation, HBV DNA was extracted from the cells and detected by PCR. The neutralization effect was determined based on the PCR results.

RESULTSTwo HBV stocks suitable for the neutralization assay were selected from 18 serum samples collected from patients with hepatitis B. The neutralization assay was optimized in the conditions of using 10 infectious doses of the HBV stock and incubating the cell culture for 24 hours prior to PCR detection. Four immune sera obtained from mice immunized with commercial HBV vaccine and 2 serum specimens from mice immunized with 2 new HBV vaccine candidates definitely blocked the in vitro HBV adsorption. However, 4 sera obtained from normal mice and 2 sera from mice immunized with 2 hepatitis E virus vaccine candidates did not show any neutralizing activity.

CONCLUSIONThe established new PCR-based in vitro HBV neutralization assay is a simple, rapid and economic assay. It may be used as a model for primary evaluation for HBV vaccine candidates prior to primate assay.

Animals ; Cell Line, Tumor ; DNA, Viral ; genetics ; Hepatitis B ; blood ; immunology ; Hepatitis B Vaccines ; immunology ; Hepatitis B virus ; genetics ; immunology ; isolation & purification ; Humans ; Immune Sera ; blood ; immunology ; Immunization ; Mice ; Mice, Inbred BALB C ; Neutralization Tests ; methods ; Polymerase Chain Reaction ; methods ; Reproducibility of Results