Lipopolysaccharide modification enhances the inhibitory effect of clodronate liposomes on hepatic fibrosis by depletion of macrophages and hepatic stellate cells.

Hepatic fibrosis is a complex chronic liver disease in which both macrophages and hepatic stellate cells (HSCs) play important roles. Many studies have shown that clodronate liposomes (CLD-lipos) effectively deplete macrophages. However, no liposomes have been developed that target both HSCs and macrophages. This study aimed to evaluate the therapeutic efficacy of lipopolysaccharide-coupled clodronate liposomes (LPS-CLD-lipos) and the effects of liposomes size on hepatic fibrosis. Three rat models of hepatic fibrosis were established in vivo; diethylnitrosamine (DEN), bile duct ligation (BDL), and carbon tetrachloride (CCl4). Hematoxylin and eosin staining and serological liver function indices were used to analyze pathological liver damage. Masson's trichrome and Sirius red staining were used to evaluate the effect of liposomes on liver collagen fibers. The hydroxyproline content in liver tissues was determined. In vitro cell counting kit-8 (CCK-8) and immunofluorescence assays were used to further explore the effects of LPS modification and liposomes size on the killing of macrophages and HSCs. Both in vitro and in vivo experiments showed that 200 nm LPS-CLD-lipos significantly inhibited hepatic fibrosis and the abnormal deposition of collagen fibers in the liver and improved the related indicators of liver function. Further results showed that 200 nm LPS-CLD-lipos increased the clearance of macrophages and induced apoptosis of hepatic stellate cells, significantly. The present study demonstrated that 200 nm LPS-CLD-lipos could significantly inhibit hepatic fibrosis and improve liver function-related indices and this study may provide novel ideas and directions for hepatic fibrosis treatment.

[Experimental study on the retentive force of cobalt-chromium alloy, pure titanium and vitallium cast clasps in the simulated 3-year clinical use].

PURPOSE: To investigate the changes of retentive force of cobalt-chromium alloy, pure titanium and vitallium cast clasps in the simulated 3-year clinical use. METHODS: Fifteen metal abutment crowns made of No.QT800-2 nodular cast iron were used in the test. Five clasps from each of the following alloys: cobalt-chromium alloy, pure titanium and vitallium were fabricated. The undercut depth was 0.25 mm. A masticatory simulator was used to cycle the clasp on and off the metal abutment crown 5000 times, simulating 3-year clinical use. Retentive force was measured 11 times during this process. SPSS13.0 software package was used to analyze the results. Casting defects were observed using X-ray non destructive testing (X-ray NDT) before cyclic test. Surface characteristics were qualitatively evaluated using scanning electron microscope (SEM) before and after cyclic test. RESULTS: The results indicated that there were significant differences (P=0.000) in the retentive force of the 3 groups before and after the cyclic test. The highest retentive force was recorded in the vitallium clasps, and the lowest retentive force was measured in the pure titanium clasps. The results of X-ray NDT depicted the typical casting defect seen at the end of the connector. SEM examination revealed that no evidence of pores and cracks in the inner surfaces of the 3 groups was found before cyclic test. Wear was evident in the inner surfaces of the 3 groups but none of the clasps exhibited any evidence of cracks after cyclic test through SEM examination. CONCLUSIONS: In this in vitro test, vitallium clasps show the best retentive force in the 3 groups before and after 5000 cycles at 0.25 mm undercut depth. Cobalt-chromium alloy and vitallium clasps can maintain ideal retentive force at 0.25mm undercut depth in the long-term use. Wear may be one of the reasons for the loss of retentive force of clasps in the cyclic test.

[Rehabilitation by hollow obturator prosthesis immediately after total maxillectomy for malignant tumor].

OBJECTIVE: The feasibility and clinical effects of hollow obturator prosthesis for the repair of maxillofacial defect immediately after maxillectomy for cancer were assessed. METHODS: Thirteen patients with T3-4aN0M0 maxillary neoplasm were treated by the prostheses immediately after maxillectomy. According to the 3D-CT reconstruction of nasal sinus, the 3D stereoscopic prototype was constructed before the surgery. Simulating surgery with Surgicare 5.0 software and then the prosthesis 3D stereoscopic model was shaped. The prosthesis was made quickly and precisely with methacrylate resins according to the model and the print mold before surgery, with supplementary tooth at the bottom of prosthesis. In the surgery, the prosthesis was installed instantly after maxillectomy. The patients were followed up at 1, 3 and 6 month after the surgery, respectively. The facial features and the pronunciation clarity were examined and the questionnaires were carried out in the patients, with comparation by paired t-test. The hollow obturator prosthesis would be replaced by permanent prosthesis made of methacrylate resins at 6 month after the surgery. RESULTS: The hollow obturator prostheses were installed accurately and maxillofacial defects were repaired immediately after maxillectomy in the 13 patients. Postoperative follow-up showed there were significant differences in eyeball sagging (t = 4.67, P < 0.05), mid-facial region collapse (t = 5.67, P < 0.05), and pronunciation clarity (t = 16.38, P < 0.05) between patients with and without prostheses. Questionnaires showed that all the patients were satisfied with the retention of prostheses, the improvement of appearance, the improvement of the symptom of water choking and speech definition. Six months after the surgery, the hollow obturator prostheses were replaced smoothly by permanent prostheses in 11 of the 13 patients. CONCLUSION: The precise and instant repair of maxillofacial defect by prosthesis after maxillectomy can improve survival quality of patient.

[The reconstruction of geometric models of dentition defects based on 3-dimensional industrial computed tomography image].

PURPOSE: A technique on data capture of plaster models for building 3-dimensional geometric models of dentition defects was presented for the purpose of further computer-aided design and manufacture (CAD/CAM)of removable partial denture. METHODS: A plaster model with dentition defects was scanned with low energy X-ray industrial computed tomography (ICT) for ICT image. The data after image processing and vectorization were transferred to a customized reverse engineering software system, and a CAD model of dentition defects was reconstructed. Then a 3-dimensional digital model of removable partial denture framework was created with CAD/CAM software system. Import/export of the data was in STL format. RESULTS: Dense and uniform data points without blind areas were acquired and the structure of the reconstructed CAD model of dentition defects was clean and smooth. CAD model of framework was then obtained. CONCLUSIONS: The method presented is practical for 3-dimensional data capture, and it helps build reliable 3-dimensional geometric models with better spatial resolution and higher precision than conventional technique with medical CT.