ABSTRACT
BACKGROUND: In orthodontics, micro-implant anchorage in the infrazygomatic crest that cannot damage the tooth root can achieve an unobstructed overall movement of the upper dentition. However, little is reported on the stress and strain of the tooth and alveolar bone during the distal movement of the upper dentition. OBJECTIVE: To set up a three-dimensional finite element model to perform a biomechanical analysis of micro-implant anchorage in the infrazygomatic crest for the distal displacement of the upper dentition at different heights. METHODS: Cone-beam CT data from a female patient admitted for orthodontic treatment was saved in Dicom format, and imported into Mimics 16.01 software. Then, a three-dimensional model of the right maxilla and tooth dentition was made by automatically and manually selecting boundaries. The model was imported into Geomagic8.0 for removal of noise dots and smooth processing, and then it was imported into the Mimics16.01 software and meshed for the surface/body through 3 Matics software. Afterwards, three-dimensional models maxillary denture, archwires and traction hooks and implants were established by ProE5.0, and all the models were imported into ANSYS13.0 and assembled and analyzed for stress and strain analysis. RESULTS AND CONCLUSION: We successfully established the three-dimensional finite element model for biomechanical analysis of micro-implant anchorage in the infrazygomatic crest for the distal displacement of the upper dentition at different heights, and this model conformed to the anatomic features. With the increase of the height of traction hooks (1, 4, 7, 10 mm), the vertical stress of the maxillary teeth increased gradually, and had no correlation with the change of the horizontal stress. With the increase of the height of traction hooks, at the sagittal axis, the strain at midpoints of middle incisors, canine teeth, and first molars decreased gradually and the strain at the root of middle incisors and canine teeth also decreased gradually, but there was no change in the strain at the root of first molars. With the increase of the height of traction hooks, at the vertical axis, the strain at the midpoints and tooth root of middle incisors increased, while the strain of canine crown increased gradually and that of the canine root decreased; the strain at the midpoint of first molars changed a little, and the strain of the tooth root decreased gradually. The dentition rotated from clockwise to counterclockwise. To conclude, the three-dimensional finite element model made in the study is consistent with the anatomic structure, which provides a basis for biomechanical analysis of micro-implant anchorage in the infrazygomatic crest for the distal displacement of the upper dentition. The upper dentition impedance center located in the position of 4 to 7 mm of the arch wire can be used as the microimplant support site in the infrazygomatic crest.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the effects of lentiviral-mediated CXC chemokine receptor-4（CXCR-4）gene over-expression on the homing capacity of mesenchymal stem cells（MSC）in vivo.</p><p><b>METHODS</b>The MSC overexpressing CXCR-4 were constructed by using the lentiviral vector-mediated mouse MSC overexpressing the CXCR-4 gene. The BALB/c mice were divided into 3 group: simple radiation group（TBI）in which mice exposed to total body irradiation, then were infused with normal saline; EGFP-MSC group in which mice were infused with MSC（5×10）transducted by EGFP via tail vein after TBI; and CXCR-4-MSC group in which mice were infused with MSC (5×10) simultaneously carraying EGFP and CXCR-4 gene via tail vein after TBI. The mice were sacrified at 24 hours after infusion, the frozen sections were prepared to detect the distribution of infused MSC. Furthermore, the numbers of MSC homing into spleen and bone marrow was detected by flow cytometry, and the level of stromal cell-derived factor-1(SDF-1) was detected by ELISA.</p><p><b>RESULTS</b>The frozen section showed that the CXCR-4 over-expression could significantly enhance the efficacy of MSC homing into lung, liver and spleen; the flow cytonetry detection slowed that the number of over-expressed CXCR-4 MSC homing into spleen and bone matrow was sigmificantly higher than that in EGFP-MSC group（P<0.05）, the ELISA showed that the SDF-1 level in peripheral blood and bone marrow after 24 hours of irradiation significantly incrtaoed （P<0.05）, moreover, the SDF-1 level increase was associcted with horming efficacy of MSC with CXCR-4 overexpression.</p><p><b>CONCLUSION</b>overexpression CXCR-4 gene mediated by lentiviral vector can prmote the efficacy of MSC homing into spleen and bone marrow.</p>
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Growing attention on the rare diseases promotes the work of the government legislation, so a series of rare diseases related policies have been introduced. However, under the conditions of economy, population, social security and so on, China’s rare disease medical care and drug development are still in the initial stage. This paper elaborates and analyzes the status and future development of rare disease drugs, and provides advice for the policy formation of rare diseases and industrial development.
ABSTRACT
<p><b>OBJECTIVE</b>To study and evaluate the curative effect and mechanism of Qiangxin Granule (QXG) in intervening chronic heart failure (CHF) rats with Xin-qi deficiency complicated blood stasis and edema syndrome (XQD-BS-ES).</p><p><b>METHODS</b>Totally 72 SD rats of clean grade were randomly divided to the normal control group (n =10) and the model group (n = 62). The XQD-BS-ES rat model was established by adriamycin plus propylthiouracil method. Survived modeled rats were then randomly divided to 5 groups i.e., the model group (n = 11, administered with normal saline by gastrogavage), the Western medicine (WM) group (n =11 , administered with perindopril and hydrochlorothiazide by gastrogavage), the low dose QXG (QXG(L)) group (n = 11, administered with 9.26 g/kg QXG by gastrogavage), the middle dose QXG (QXG(M)) group (n = 11, administered with 18.52 g/kg QXG by gastrogavage), the high dose QXG (QXG(H)) group (n = 11, administered with 37.04 g/kg QXG by gastrogavage). After 4 weeks of treatment, left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), brain natriuretic peptide (BNP), heart rate (HR), respiratory rate (RR), urine output, ear temperature, exhaustive swimming test (EST), tri-iodothyronine (T3), tetra-iodothyronine (T4), thyroid stimulating hormone (TSH), as well as heart, lung, liver weight index and their pathological sections, and high sensitivity C-reactive protein (HS-CRP), angiotensin II (Ang II), carbohydrate antigen 125 (CA125) were detected and compared.</p><p><b>RESULTS</b>Compared with the normal control group, LVEF, LVFS, BNP, HR, RR, urine output, ear temperature, EST, T3, T4, TSH, HS-CRP, Ang II, and CA125 changed significantly in the model group (P < 0.01). Compared with the model group after treatment, LVEF, LVFS, BNP, urine output, EST, T4, heart and liver weight index, HS-CRP, Ang II, CA125 were significantly improved in each QXG group (P < 0.05, P < 0.01). Moreover, TSH was improved in the QXGL and QXG(M) groups (P < 0.05); ear temperature and T3 in the QXG(M) were also improved (P < 0.05); the lung weight index decreased in the QXG(M) and QXG(H) groups (P < 0.01). Compared with the WM group, T4 and CA125 were obviously improved in all QXG groups (P < 0.01); BNP and ear temperature were obviously improved in QXG(L) and QXG(M) groups (P < 0.05, P < 0.01); LVEF, LVFS and TSH were obviously improved in the QXG(M) group (P < 0.05, P < 0.01). And as far as each treatment group, LVEF, LVFS, urine output increased significantly after treatment (P < 0.01); EST obviously increased in QXG(M) and QXG(H) groups (P < 0.01); ear temperature increased in all QXG groups (P < 0.05, P < 0.01). Moreover, compared with the model group, pathological changes of heart, lung, and liver were improved to some degree in each treatment group, especially in the QXG(M) group.</p><p><b>CONCLUSIONS</b>Good curative effect was shown in each QXG group. QXG could improve LVEF, LVFS and BNP of CHF rats of XQD-BS-ES, as well as T3, T4, TSH, EST, urine output, and ear temperature. Moreover, QXG showed superiority than WM group in this respect.</p>
Subject(s)
Animals , Rats , Angiotensin II , C-Reactive Protein , Chronic Disease , Drug Therapy , Drugs, Chinese Herbal , Pharmacology , Therapeutic Uses , Edema , Heart , Heart Failure , Drug Therapy , Heart Ventricles , Medicine, Chinese Traditional , Natriuretic Peptide, Brain , Qi , Rats, Sprague-Dawley , Syndrome , Thyrotropin , Ventricular Function, LeftABSTRACT
<p><b>OBJECTIVE</b>To establish and evaluate chronic heart failure (CHF) rat model of Xin-qi deficiency complicated blood stasis and edema syndrome (XQD-BSES).</p><p><b>METHODS</b>Totally 40 SD rats were randomly divided into the normal control group (Control), the propylthiouracil (PTU) group, the adriamycin (ADR), and the ADR + PTU group. Normal saline was used as equivalent solvent of each group. Rats in the Control group were intragastrically and intraperitoneally injected with normal saline. Rats in the PTU group were intragastrically injected with PTU suspension and intraperitoneally injected with normal saline. Rats in the ADR group were intragastrically injected with ADR solution and intraperitoneally injected with normal saline. And rats in the ADR + PTU group were intragastrically injected with PTU suspension and intraperitoneally injected with ADR solution. The dose of PTU was 0.2% of daily forage weight, once daily. The dose of ADR was 3.5 mg/kg, once per week. The modeling lasted for 6 weeks. Left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), brain natriuretic peptide (BNP), heart rate (HR), respiratory rate (RR), urine output, ear temperature, exhaustive swimming test (EST), Tri-iodothyronine (T3), tetra-iodothyronine(T4), thyroid stimulating hormone (TSH) as well as heart, lung, liver weight indices and their pathological sections were integrated and compared.</p><p><b>RESULTS</b>Compared with the Control group, LVEF, LVFS, BNP, HR, RR, heart, lung, liver weight indices, urine output, ear temperature, EST, and T3, T4, and TSH changed significantly in the ADR group, the PTU group, and the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure occurred in pathological sections of heart, lung, and liver. Compared with the ADR group, LVEF, LVFS, BNP, and lung, liver weight indices, urine output, ear temperature, T3, T4, and TSH changed significantly in the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure were more serious in pathological sections of heart, lung, and liver. Compared with the PTU group, LVEF, LVFS, BNP, HR, RR, urine output, EST, T4, heart and lung weight indices changed significantly in the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure were quite serious in pathological sections of heart, lung, and liver.</p><p><b>CONCLUSION</b>ADR + PTU was an appropriate method to establish CHF rat model of XQD-BSES.</p>