OBJECTIVETo probe the implant-bone-interface stress distribution of zygomatic implant denture concerning different implant sites.

METHODSThree-dimensional finite element model for severe atrophy maxillary posterior-tooth area was established biomechanically in this study by computer technique and zygomatic implant was simulated into the model in the first-maxillary-premolar region, the second-maxillary-premolar region, the first-maxillary-molar region and the second-maxillary-molar region respectively. Vertical loading, buccal (30 degrees) loading and lingual (30 degrees) loading were preformed, 100 N. Then these load cases were calculated and analyzed.

RESULTS1) When the implant site was placed in the first-maxillary-premolar region, the buccal side of zygomatic implant exposed out of the bone and didn't meet the clinical request. 2) As far as the tensile stress peak value in the maxillary posterior-tooth area was concerned, the highest value was recorded when the implant was placed in the second-maxillary-molar region, and then the medium value was recorded when the implant was placed in the second-maxillary-premolar region, and the smallest was recorded when the implant in the first-maxillary-molar region. As far as the compressive stress peak value in the maxillary posterior-tooth area was concerned, the highest value was recorded when the implant was placed in the second-maxillary-molar region, and then the medium was recorded when the implant was in the first-maxillary-molar region, and the smallest value was presented when the implant was in the second-maxillary-premolar region. As far as the tensile and compressive stress peak values in the zygomatic area were concerned, the highest value was recorded when the implant was in the second-maxillary-premolar region, and then the medium value when the implant was in the first-maxillary-molar region, and the smallest when the implant was in the second-maxillary-molar region.

CONCLUSIONThe first-maxillary-molar region is the best implant site of zygomatic implant denture.

Bicuspid ; Dental Implants ; Dental Prosthesis, Implant-Supported ; Dentures ; Finite Element Analysis ; Humans ; Maxilla ; Molar ; Stress, Mechanical

OBJECTIVETo investigate the treatment and prevention of infection after alveolar crest onlay bone graft.

METHODSFrom January 2006 to May 2010, 11 infection cases after onlay graft on alveolar crest were reviewed to evaluate the infection time, clinical situation, treatment measure, and therapeutic effect.

RESULTSThe infection of all 11 cases occurred about 15 days after bone graft, which showed either soft tissue fistulae or bone graft exposure in the oral cavity. Three cases failed because of persistent infection. The infection of the other 8 cases was controlled after a series of comprehensive therapy, and most of the bone graft was reserved and implant restoration finally completed.

CONCLUSIONSAfter the effective and comprehensive therapy, infected bone graft can be reserved. But to ensure the survival rate of bone graft, the most important thing is to prevent infection in perioperative period.

Alveolar Ridge Augmentation ; Bone Transplantation ; Dental Implants ; Follow-Up Studies ; Humans ; Infection ; Inlays ; Retrospective Studies

Aged ; Fatty Liver ; complications ; metabolism ; Female ; Humans ; Insulin Resistance ; Lipids ; Liver ; metabolism ; Male ; Metabolic Diseases ; metabolism ; Middle Aged ; Non-alcoholic Fatty Liver Disease

OBJECTIVETo investigate the effects of alveolar bone resorption on stress of tooth/implant-supported restoration connected by precision attachment using three-dimensional finite element(FEM) approach.

METHODSThe FEM was applied to analyze the stress distribution of tooth/implant-supported restoration connected by precision attachment under various loading conditions when the alveolar bone was absorbed to different level.

RESULTSThe stress values of the tooth, implant and their surrounding bone increased when their surrounding bone decreased by bone absorption.

CONCLUSIONThe stress values of the tooth, implant and their surrounding bone were closely related with the bone resorption.

Alveolar Process ; Bone Resorption ; Bone and Bones ; Dental Prosthesis, Implant-Supported ; Dental Stress Analysis ; Finite Element Analysis ; Humans

Using transplantable erythroblastic leukemia cells of EL9611(H-2d), the cells were inoculated to CB6F(1)(H-2d/b) generation of BALB/c x C57BL/6 mouse, the biological characterization of erythroblastic leukemia in haploidentical mouse was studied, that provides an experimental model for the study of graft-versus leukemia (GVL) with bone marrow or stem cell transplantation. When 10(3) - 10(8) of the spleen cells of EL9611(H-2d) had been intravenously inoculated to CB6F(1) mouse, the erythroblastic leukemia cells were transplanted successively and the F(1) generation of erythroblastic leukemia model in mice was established with 100% incidence of erythroblastic leukemia. There was a linear relationship between the survival time and the number of leukemic cell. The survival time of the mice was (9.6 +/- 0.8) days when 10(6) cells were inoculated. If the CB6F(1) mouse was transplanted successively for four generations, the incidence was 100%. The main targets for the leukemic EL9611(H-2d) cells were liver, spleen and marrow. The reaction of the erythroblastic leukemia cells for hemoglobin staining was positive, while the peroxidase reaction was negative. These cells were sensitive to some chemotherapeutic drugs, such as cytosine arabinoside and cyclophosphamide. This study presents the convenience for the studies on the GVL with haplo-allogeneic transplantation, in the F(1) generation of erythroblastic leukemia model of the commonly-used CD57BL/6 x BALB/c mouse.
Animals ; Cell Division ; Disease Models, Animal ; H-2 Antigens ; analysis ; Leukemia, Erythroblastic, Acute ; immunology ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Inbred Strains ; Neoplasm Transplantation ; Survival Analysis ; Tumor Cells, Cultured

Objective To study the bone biomechanics of the rabbit osteoporosis models induced by dexamethasone sodium phosphate injection (DX) using a combined treatment modality of 99Tc-MDP and GuKangLing.Methods Rabbits were intramuscularly injected with DX (2 mg/kg) twice a week for 6 weeks.The animal osteoporosis model group (Group C) and normal group (Group A) were compared to confirm the model was available.Another control group (Group B),the osteoporosis control group (Group D) were set for the comparison at the end of the experiment.The 99Tc-MDP therapy group (Group E),GuKangLing therapy group (Group F) and 99Tc-MDP plus GuKangLing therapy group (Group G) were included in the study.The treatment lasted for 16 weeks.The bone biomechanics,cytopathology bone histomorphology,bone mineral density (BMD),X-ray,CT,bone scintigraphy and serum bone alkaline phosphatase (BALP)and P (bone gla protein) were chosen as the markers or methods to evaluate the treatment results (excellent,effective and invalid).The analysis of variance (ANOVA) and t-test were used for group comparison analysis.Results Cytopathology result indicated that there was no bone trabecula destruction in Group A.However,there was distinct bone destruction in Group C.The bone biomechanics (left femur head (265.914 ±52.773) N,L4(369.671 ±94.919) N),BMD(left femur (0.238 ±0.016) g/cm2,L4(0.236 ±0.016) g/cm2)and bone histomorphology ( (66.230 ± 10.848) ％ ) in Group C reduced clearly as compared with Group A ((405.343±55.410) N,(750.870±53.718) N,(0.294±0.017) g/cm2,(0.302±0.023) g/cm2,( 131.500 ± 21.846) ％ ) ( t ≥4.550,all P ＜ 0.01 ).Radionuclide bone scan also showed that the uptake of tracers was higher by the main arthrosis in Group C than that in Group A.Vertebra was not clearly visualized on bone scan image.There were significant differences between Group A and Group C in serum BALP and P ((45.000±7.303) vs (12.485 ±1.512) U/L,(0.168±0.018) vs (0.115 ±0.017) μg/L,t =4.126,5.476,both P ＜ 0.01 ),which indicated that the animal osteoporosis model was available.The pathological results showed an improved recovery of bone structure and trabecular in Groups E and G,but a worse recovery in Group F.Biomechanics result in Groups E and G (left femur head (386.457 ±77.077) N and (432.771 ± 17.525) N,L4(649.550 ± 126.859) N and (655.443 ±76.555) N) improved apparently,which were similar to Group B.The radiotracer uptake in Group F was lower than that in group D.The bone biomechanics,bone histomorphology,BMD,serum BALP and P after the treatment showed significant differences in Groups E,F and G (F:8.556 - 31.608,all P＜0.01 ),and the bone biomechanics result in Group G was a little better than that in Group E (t =2.625,P ＜ 0.05 ).The results of Group G and E were considered as excellent,and Group F was considered as effective.Conclusions The treatment of 99Tc-MDP combined with GuKangLing could improve the bone biomechanics of rabbit osteoporosis models and may be a potential method to increase the bone strength for resisting external force.

OBJECTIVETo explore the effect of bone morphogenetic protein (BMP) to activate mesenchymal stem cells of skeletal muscle for rescuing bone marrow failure.

METHODSThe study was performed on lethal rat acute aplastic anemia model induced by combined 5-fluorouracil (5-FU) and busulfan. The rh-BMP-2 was implanted into the thigh muscle of the rats at 3 days before aplastic anemia was induced. In the control group the rats were implanted with agar into the thigh muscle. The blood picture, pathologic changes and the mortality in two groups were observed. At the same time, rh-BMP-2 were implanted into the thigh muscle of normal Kun-min mice for dynamic control observation of the implantation local morphological changes, colony forming units-spleen (CFU-S) and stem cell growth factor (SCF) expression of the stroma cells of ectopic ossicles induced by BMP.

RESULTSAt 7 days after BMP implantation in the mice the mesenchymal cells around BMP in muscle proliferated, and appeared in bone marrow to form an ectopic ossicles. The SCF expression of stroma cells in ectopic ossicles were higher than that of self-bone marrow. 56.3% of BMP-treated aplastic rats were survived over 3 months and its hematopoiesis was completely reconstituted and the histo-morphological picture of the spleen and bone marrow were recovered to normal. But in the control group only one of 23 rats was survived, the remainder died of hematopoietic failure.

CONCLUSIONSBMP-implantation into the skeletal muscle could rescue the bone marrow hematopoietic failure. The mechanism might be related to the BMP activated auto-mesenchymal cells of skeletal muscles to direct hematopoietic cell differentiation. In our hands it might create a new pathway for utilization of auto-muscle derived mesenchymal cells to reconstitute hematopoiesis.

Anemia, Aplastic ; chemically induced ; pathology ; therapy ; Animals ; Bone Morphogenetic Proteins ; therapeutic use ; Busulfan ; Cell Differentiation ; Female ; Fluorouracil ; Hematopoiesis ; Hematopoietic Stem Cells ; cytology ; Implants, Experimental ; Male ; Mice ; Muscle, Skeletal ; surgery ; Rats ; Rats, Wistar ; Recombinant Proteins ; therapeutic use ; Stem Cells ; cytology

For effectively enhancing the anti-leukemia effect of chemotherapeutic agents, and meanwhile decreasing the side effect of these agents, the study has been made to explore the synergistic effect of low dose irradiation (LDI) combined with Ara-C on murine leukemia and its mechanism. Firstly, an optimal scheme of low dose total body irradiation combined with Ara-C was established in L615 leukemia (T lymphocytic leukemia) mouse model. The machanism of the enhancing effect was explored by patho-morphological observation, examination of residual leukemia cells, the expression of GM-CSF on the surface of marrow stromal cells and in the bone marrow cultural supernatants. The results showed that the optimal scheme was 300 cGy irradiation at 4 days after inoculation of leukemic cells followed by Ara-C 30 mg/kg x 3 days in an interval of 1, 2 or 3 days after irradiation. The mean survival time of the L615 leukemia mice in LDI + Ara-C combined treatment groups was longer than that of control groups. The percentage of long-term survival mice (> 30 days) was the highest (58% - 72%), too. 17% of the mice were be cured. The numbers of blood leukocytes and marrow nucleated cells were transiently decreased in combined treatment group, and then recovered rapidly. Slight myelosuppression and marrow sinus dilation and congestion were seen after 300 cGy irradiation. The expression of GM-CSF either on the stromal cells or in marrow cultural supernatant after irradiation increased strikingly (P < 0.05). Therefore, LDI combined with Ara-C possesses synergistic effect. The mechanism is possibly related to three facts: LDI could increase the permeability of bone marrow sinus; LDI could promote marrow stromal cells to produce some cytokines (such as GM-CSF, etc.) which drive leukemia cells into cell cycle to make the cells more sensitive to chemotherapeutic agents; and LDI could augment Ara-C-induced cytotoxicity through the mechanism of apoptosis.

Objectives: To evaluate the association of illicit drug use with bone mineral density (BMD) and hip geometric parameters at the narrow neck. Methods: This is a cross-sectional matched cohort study conducted in the Hong Kong Chinese population. Associations with illicit drug use were estimated using linear regression for BMD (lumbar spine and femoral neck) and hip geometrical parameters (cross-sectional area [CSA], cross-sectional moment of inertia [CSMI], section modulus [SM], average cortical thickness [ACT] and BMD at the narrow neck) after adjusting for age, body mass index (BMI), smoking status, drinking status, physical activity, and history of antipsychotic and antidepressant use. Mean difference and 95% confidence intervals (95% CI) were calculated between 108 illicit drug users and 108 controls using an adjusted linear model and cluster-robust standard errors after matching by age and sex. The false discovery rate was used to correct for multiple testing. Results: Illicit drug users had a significantly lower BMD (g/cm2 ) at the lumbar spine (mean difference: -0.062; 95% CI: -0.108 to − 0.015), and femoral neck (mean difference: -0.058; 95% CI: -0.106 to − 0.010) in the fully adjusted model. Illicit drug users also had a significantly lower CSA (mean difference: -0.238 cm2 ; 95% CI: -0.462 to − 0.013), ACT (mean difference: -0.018 cm; 95% CI: -0.030 to − 0.006) and BMD (mean difference: -0.070 g/ cm2 ; 95% CI: -0.128 to − 0.012) at the narrow neck. Conclusions Illicit drug use is associated with lower BMD and bone strength. Future studies evaluating the risk of illicit drug use with fragility fracture are warranted.

OBJECTIVETo investigate the hemostatic effect of spleen-invigorating, qi-replenishing and blood-containing formula on simvastatin-induced zebrafish hemorrhage model, and to compare with the effect of clearing heat and cooling blood formula.

METHODSZebrafishes from breed A B line were treated with 0.5 µmol/L simvastatin for 24 hours to establish zebrafishes hemorrhage model. Under strict blinded experimental conditions, the above mentioned zebrafishes were then treated with experimental drug of different concentrations at the maximum non-lethal dose. The intervention effect of spleen-invigorating, qi-replenishing and blood-containing formula was comprehensively assessed by examining the main observational parameters, such as bleeding reduction rate and hemostasis rate while referring to additional parameters, such as blood flow, improvement rate of blood flow, velocity of movement, improvement rate of motion, which are characteristics of spleen qi deficiency.

RESULTSWhen the hemostatic effect of experimental drug B1 at the concentrations of 500 and 1 000 µg/ml, zebrafish bleeding rates were 30% and 15%, the hemostatic rate was 60% and 80%, respectively; when the experimental drug B2 at concentration of 500 and 1 000 µg/ml, Zebrafish bleeding rates were 45% and 40%, the hemostatic rate was 40% and 47%, respectively, showing that experimental drug B1 was superior to B2 in terms of decreasing bleeding rate and improving hemostatic effect in zebrafish. In the equal concentration, the experimental drug B1 was superior to B2 in terms of increasing and improving the blood flow of hemorrhagic zebrafish. Promotion and improvement of motion: in equal concentration, experimental drug B1 was superior to B2 in terms of promoting the motion velocity and increasing the improving rate of motion in zebrafish.

CONCLUSIONThe spleen-invigorating, qi-replenishing and blood-containing formula displays a good hemostatic effect on simvastatin-induced hemorrhage of zebrafish. It also boosts the blood flow and motion velocity in hemorrhagic zebrafish, therefore, providing an experimental basis for the treatment of syndrome of spleen failing to control blood by spleen-invigorating, qi-replenishing and blood-containing formula.