[Finite element analysis of different intramedullary fixation methods for the treatment of senile pubic ramus fractures].

Objective: To evaluate the biomechanical stability of elastic intramedullary nail in the treatment of pubic ramus fractures by finite element analysis, and to compare the stability of elastic intramedullary nail with cannulated screw intramedullary fixation.

Methods: The CT data of the pelvis of a volunteer were selected, and the three-dimensional model of the pelvis was reconstructed by reverse engineering software and the fracture of the pubic ramus fractures was simulated by osteotomy. The hollow nail model, single elastic nail model and double elastic nailmodel were assembled with different implants respectively.

Attenuation of inflammatory response by 25- hydroxyvitamin D3-loaded polylactic acid microspheres in treatment of periodontitis in diabetic rats.

Objective: To investigate the inhibitory effects of 25-hydroxyvitamin D3 (25(OH)D3)-loaded polylactic acid (PLA) microspheres on inflammatory response in diabetic periodontitis.

Methods: 25(OH)D3-loaded PLA microspheres were produced using emulsion-solvent evaporation method. Rat bone marrow stromal cells (BMSCs) cultured with Aggregatibacter actinomycetemcomitans in high glucose medium were chosen to mimic diabetic periodontitis.

Effect of proximal contact strength on the three-dimensional displacements of implant-supported cantilever fixed partial dentures under axial loading.

Objective: This study investigated the effect of proximal contact strength on the three-dimensional displacements of cantilever fixed partial denture (CFPD) under vertically concentrated loading with digital laser speckle (DLS) technique.

Methods: Fresh mandible of beagle dog was used to establish the implant-supported CFPD for specimen. DLS technique was employed for measuring the three-dimensional displacement of the prosthesis under vertically concentrated loading ranging from 200 to 3000 g.

[Measuring three-dimensional displacement of tooth-supported rigid fixed bridge under oblique concentrated loading using digital laser speckle photography].

Objective: To measure three-dimensional displacements of rigid fixed bridge under oblique concentrated loading and to analyze the effect of displacement on the stability of abutment teeth.

Methods: Right mandible of Beagle dog was used to establish the tooth-supported rigid fixed bridge. Digital laser speckle photography was employed to measure the three-dimensional displacements of the prosthesis under oblique concentrated loading ranging from 200 g to 3000 g.

Temporal change in NMDA receptor signaling and GABAA receptor expression in rat caudal vestibular nucleus during motion sickness habituation.

Repeated exposure to a provocative motion stimulus leads to motion sickness habituation indicative of the existence of central processes to counteract the disturbing properties of the imposed motion. In the present study, we attempt to investigate whether NMDA and GABA(A) receptors in rat caudal vestibular nucleus neurons are involved in motion sickness habituation induced by repeated Ferris-wheel like rotation in daily session (2h/d). We showed that defecation response increased and spontaneous locomotion decreased within 4 sessions (sickness phase).

Flavokawain B induces apoptosis of human oral adenoid cystic cancer ACC-2 cells via up-regulation of Bim and down-regulation of Bcl-2 expression.

Novel effective drugs are still urgently needed in the prevention and treatment of oral adenoid cystic carcinoma (ACC). In this study, we have assessed the antitumor potential and molecular mechanisms of flavokawain B (FKB) as a kava chalcone on the ACC-2 cell line in vitro. The results demonstrated that FKB could significantly inhibit the cell proliferation of ACC-2 in a dose-dependent manner that was associated with induced apoptosis and cell cycle G2-M arrest, and the half maximal inhibitory concentration (IC50) of flavokawain-B treatment for 48 h was estimated to be 4.

[Intestinal absorption of the effective components of Schisandra chinensis Baill by rats single-pass perfusion in situ].

The aim of the study is to investigate rat intestinal absorption behavior of three main active components, schisandrol A, schisandrin A and schisandrin B in Schisandra chinensis Baill extracts in intestine of rats. With phenol red as the indicator, in situ single pass intestinal perfusion (SPIP) model was used and the concentrations of three main active components in perfusion solution of different intestinal segments (duodenum, jejunum, ileum, and colon) were determined by HPLC in combination with diode array detection. The results showed that the absorption rate constant (Ka) and effective permeability values (Peff) of three main active components in Schisandra chinensis Baill extracts had significant difference (P < 0.

Decreased Fos protein expression in rat caudal vestibular nucleus is associated with motion sickness habituation.

We investigated the temporal change of Fos protein expression in the caudal vestibular nucleus of rats exposed to daily 2-h Ferris-wheel like (FWL) rotation. Repeated rotation (2h daily for 14 consecutive days) caused an initial increase in defecation, followed by a gradual decline back to the baseline level after 8 rotation sessions. Unlike defecation, the Kaolin consumption of rats showed a bitonic function during the daily rotation sessions (2h daily for 33 consecutive days) and finally recovered to the baseline after about 31 sessions.

[A structural mechanics study with human maxillary premolar].

Objective: To evaluate the stress distribution and offset of dental and periodontal tissues imposed by changes in inner diameter of pulp cavity.

Methods: Six models of maxillary second bicuspid tooth with different inner diameter of pulp cavity were established, including: (1) calcificated pulp without pulp chamberi (2) mostly calcificated pulp chamber with inward reduction of 0. 5 mm in normal pulp cavity; (3) initially calcificated pulp chamber with inward reduction of 0.

[Relationship between tissular structure and strength of fresh bull periodontal ligament].

Objective: To study the relationship between the width and the content of fiber in peridontal ligament (PDL) and the strength of peridontal membrane.

Methods: Fresh mandible of bull was obtained to prepare for a 5 mm x 2 mm x 10 mm cuboid including teeth, peridontal membrane, and alveolar bone. The width of the PDL was measured under a stereomicroseope.

[Effect of different dynamic mechanical strain on the proliferation and synthetic function of human periodontal ligament fibroblasts in vitro].

Objective: To study the changes in the proliferation and synthetic function of human periodontal ligament fibroblasts (HPDLF) in response to dynamic mechanical strains of different modes, magnitudes and durations.

Methods: Using a 4-point bending system, the effect of dynamic mechanical strains of different modes, magnitudes and durations on the proliferation of HPDLF was investigated by analyzing the cell cycle changes with flow cytometry (FCM), and the total protein level and the activity of alkaline phosphatase (ALP) in HPDLF were assayed by quantitative analysis.

Results: The percentage of G(0)/G(1) cell decreased, S phase cells increased, and the proliferation index (PI), total protein level and activity of ALP were augmented significantly in response to dynamic mechanical micro-strains.

[Mutations in NPHS2 in familial steroid-resistant nephrotic syndrome in Southern Chinese Han ethnic group].

Objective: Mutations in NPHS2 mapped to 1q25-q31 and encoding podocin, which is exclusively expressed in glomerular podocytes, are responsible for autosomal recessive familial steroid-resistant nephrotic syndrome (SRNS) with minor glomerular abnormalities or focal segmental glomerulosclerosis. Different groups from European and North American countries have screened NPHS2 mutations in familial SRNS with recessive inheritance, documenting a mutation detection rate of 45% - 55% in families. This study aimed to examine mutations in the NPHS2 gene in Southern Chinese Han ethnic group patients with familial SRNS.

[Regulation of collagen type I and fibronectin mRNA expression by mechanical stress in cultured human periodontal ligament fibroblasts].

Objective: To investigate the effect of different dynamic tensional and compressive stress on the mRNA expression of collagen type I and fibronectin in cultured human periodontal ligament fibroblasts (hPDLF), and explore the regularity of functional change in hPDLF.

Methods: A new cyclic strain loading apparatus was used for mechanically loading. Cells cultured in vitro were loaded with three levels (1000 microstrain, 2000 microstrain, 4000 microstrain) of tensional and compressive forces and collected at different time (0 h, 0.

[Effect of gilding technique on the element release of beryllium ion from Vera Bond titanium alloy].

Objective: To research the effect of gilding technique on the element release from Vera Bond Ti alloy exposed to artificial saliva.

Methods: To divided experimental group into 4 groups: common used Ti porcelain crown (controlling group, A1), polished Ti porcelain crown (polished group, A2), gilded Ti porcelain crown (gold-plating group, A3), gilded Ti porcelain crown prolonged 50% (gold-plating prolonged 50% group, A4). T measure the quantity of beryllium ion in artificial saliva after 1 month, 3 months and 6 months by means of ICP-AES.

[Regulation of integrin beta1 mRNA expression by mechanical stress in human periodontal ligament fibroblasts].

Objective: To investigate the effect of different kinds of mechanical stress on the mRNA expression of integrin beta1 subunit in cultured human periodontal ligament fibroblasts (hPDLF).

Methods: To scalp and remove the periodontal ligament attached to the mid-third part of the fresh root of young premolars extracted for the cause of orthodontics. Cultured hPDLF by the method of digesting by I-type collagenase combining with tissue adhering.

[Effects of continuous adenosine infusion on pulmonary hypertension in chronically hypoxic rats].

Objective: To observe the effects of continuous subcutaneous adenosine infusion on pulmonary hypertension in chronically hypoxic rats.

Methods: Twenty-four SD rats were randomized into normoxic group, hypoxic group and adenosine-treated hypoxic group. Hypoxic environment was simulated in a chamber filled with 10% oxygen and 90% nitrogen.

[Targeted blockage of RNA binding protein E2 by decoy RNA induces the granulocytic differentiation of K562 cells].

Objective: To use a decoy RNA targeted blockage of the RNA binding protein E2 (hnRNP E2) resulting in the CCAAT/enhancer-binding protein alpha (C/EBP alpha) gene's abnormal translation and investigate its effect on the granulocytic differentiation of K562 cells and the probable molecular mechanism.

Methods: The hnRNP E2 decoy RNA expression plasmid was constructed and transfected into K562 cells with cationic liposome, and stable expression cells were obtained by G418 selection. The changes of C/EBP alpha and granulocyte colony-stimulating factor receptor (G-CSFR) gene expression were detected by RT-PCR and Western blot.

[Research of morphology for the toothmark in pocket limb].

Objective: The purpose of this study was to observe the morphological changes of toothmarks in pocket limbs and to explore the durative development of bitemarks.

Methods: Firstly a toothmark model was established by using a universal testing machine and a self-made incisor nod which was pressed particularly on pocket limbs. The changes of toothmarks were observed on alive and dead animals with time elapsing.

[Neuroprotective effects of topiramate and folic acid on young rats with kindling-induced epilepsy].

Objective: To study the neuroprotective effects of topiramate (TPM) alone or together with folic acid (FA) on young rats with kindling-induced epilepsy.

Methods: Rat models of epilepsy were prepared by pentylenetetrazol (PTZ)-induced kindling. Seventy-two 3-week-old male Wistar rats were randomly divided into 6 groups: four TPM-treated epilepsy groups (TPM 20, 40 or 80 mg/kg/d and TPM 40 mg/kg/d + FA 5 mg/kg/d), a positive control group (untreated epilepsy group) and a negative control group (normal control group).

[Effect of gilding technique on the release of elements from copper-based alloy post-core].

Objective: To evaluate the effect of gilding technique on the release of element from copper-based alloy post-core exposed to artificial saliva.

Methods: The quantities of nickel ion and copper ion released from common copper-based alloy post-core (control group), blasting gilding copper-based alloy post-core (blasting group) and burnishing gilding Copper-based alloy post-core (burnishing group) in artificial saliva after 1 month,3 months,6 months and 8 months of exposure were measured with atomic absorption spectrophotometer. The tooth tissues were stripped off at the eighth month and the oxygenization on the surface of the posts were observed.

Osteocyte: the impresario in the electrical stimulation for bone fracture healing.

Delayed healing and nonunions of bone fracture are critical problems in orthopedic surgery. Electrical stimulation has been used as a therapeutic method for enhancing bone healing for a long time. Despite unanimous clinical success, the underlying mechanism concerning bone tissue in response to electrical stimulation remains poorly understood.

[Application of insertion-type separate post on ceramic restoration of molar residual root and crown with low occlusogingival distance].

Objective: To study the clinical effects of insertion-type separate post and post-crown on ceramic restoration of molar residual root and crown with low occlusogingival distance and large root bifurcation angle.

Methods: 19 molar residual roots and crowns with low occlusogingival distance(<3 mm) and large root bifurcation angle were involved in this study. Firstly, the root canals were prepared according to their natural directions without concerning about the common path of insertion.

[Effect of the thickness of periodontal ligament on the fracture resistance of root and post-core system].

Objective: To assess the effect of the thickness of periodontal ligament on the fracture resistance of root and post-core system.

Methods: Forty-five simulated roots in the same length, taper and diameter were made of polymethacrylate (PMMA). Then the wax patterns of post-cores were cast.