Reverse engineering and rapid prototyping technique for restoration of mandibular bone defect / 生物医学工程学杂志

The application principle and procedure of reverse engineering and rapid prototyping techniques are introduced in this paper. The description is concentrated on the applications of the above techniques in medical field, especially in reconstructive surgery of mandibular bone defect.

Induction of multidrug resistance in Tca8113 cells by transient exposure to different chemotherapeutic drugs / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to determine the effect of transient exposure to chemotherapeutic drugs on multidrug resistance of Tca8113 cells.</p><p><b>METHODS</b>The MDR1 and MRP gene expressions in Tca8113 and K562/ADM cells lines were analyzed using reverse transcription polymerase chain reaction (RT-PCR), after the cells were treated with different cytotoxic drugs. The function and expressions of P-glycoprotein 170 and multidrug resistant associated protein were studied using fluorescence photometric assays.</p><p><b>RESULTS</b>The inhibitive rate of Tca8113 cells was higher than that of K562/ADM, after exposure to chemotherapeutic drugs. The transient exposure to cytotoxic drugs weakly induced MDR1 and multidrug resistant associated protein expression in Tca8113 cells. The intracellular drug concentration in K562/ADM was lower than that in Tca8113 cells.</p><p><b>CONCLUSION</b>Induction of MDR1 and multidrug resistant associated protein gene expression response to cytotoxic drugs may be related with the increased multidrug resistance in drug-treated human tumor cells.</p>

Reversal effect of hyperthemia on multidrug resistant phenomena / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was investigate the effect of hyperthemia on multidrug resistance in K562/ADM cell.</p><p><b>METHODS</b>The MDR1 (mulitdrug resistance gene) and MRP (multidrug resistant associated gene) gene expressions in Tca8113 and K562/ADM cell lines were analyzed by RT-PCR after treated with different cytotoxic drugs and different temperature (37 degrees C and 41 degrees C). The function and expression of Pgp and MRP were detected by fluorescence photometeric assays.</p><p><b>RESULTS</b>Inhibition rate of both cells was significantly enhanced by exposure to chemotherapeutic drugs and 41 degrees C temperature; Exposing to 41 degrees C hyperthemia reduced MDR1 and MRP expression and enhanced intracellular drug concentration as well in K562/ADM.</p><p><b>CONCLUSION</b>41 degrees C hyperthemia could effectively enhance the inhibition rate of chemotherapeutic drugs and partially reverse the multidrug resistance. It is suggested that hyperthemia could be used as a method to overcome multidrug resistance.</p>

Distraction osteogenesis for repair of cleft palate: an experimental study / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the repair of cleft palate (CP) bone defect under the application of distraction osteogenesis (DO); to investigate the correction mechanism in thin bone of palatal shelf and to search a possible new treatment approach for repair of CP.</p><p><b>METHODS</b>14 cats were assigned randomly to 3 groups: (1) Empty control, 2 cats unoperated with euthanasia at the end of 2 weeks; (2) Experimental control, 2 cats underwent 8 mm x 18 mm palatal osteoectomy in saggital direction as the experimental model of CP with euthanasia in 6 weeks; (3) Experimental group, 10 cats were performed the same palatal osteoectomy as group (2), the newly designed and individual manufactured intraoral distractors were fixed to teeth by brackets and to bilateral palate bone across the defect with titanium miniscrews. 4 weeks later the transport disc (TD) osteotomy were performed and gradual distraction was started after 6 days latency period at the rate of 0.4 mm x 2/day till the TD reached the opposite edge of the CP. Roentgenographic, gross meterage and ultrastructural observation were performed 2, 4, 6, 8, 12 weeks after completion of distraction.</p><p><b>RESULTS</b>All the examinations revealed the TD recombination to the opposite bone edge of the CP, simultaneously, the proportional expansion of overlay mucoperiosteal flap was achieved. The bone defect were filled with de move osteogenesis. Roentgenographically, the new bone mineralization was along the DO vector, developed from the bone cut edges bilaterally to the central translucent zone until turned to thin fissure. Comparison of the plaster casts showed no change in the occlusion or dentomaxillofacial framework.</p><p><b>CONCLUSIONS</b>The intraoral distractor is able to get both effective distraction and steady fixation. The examination results suggest that the CP bone and soft tissue defect could be repaired and acheived functional reconstruction under DO, which could be a new treatment approach for repair of CP.</p>

Transglutaminase 1 gene mutations in a family with lamellar ichthyosis / 中华皮肤科杂志

Objective To detect the mutations of transglutaminase 1 (TGM1) gene in a family with lamellar ichthyosis. Methods The genomic DNA was extracted from the proband and his family members. All the encoding exons and adjacent splice sites of TGM1 gene were amplified by PCR. Mutation scanning was carried out via direct bi-directional DNA sequencing. Also the homology of TGM1 was analyzed. Results In the proband, there was a C504T mutation located at codon 142 (R142C) in exon 3 of TGM1 gene, and a nonsense mutation of C1122T located in exon 7, which caused a premature termination of R348X and a defective polypeptide truncated by 470 amino acids in C-terminus. A heterozygote of C504T mutation was carried by the proband′s father and a heterozygote of C1122T mutation in the proband′s mother. The missense mutation of R142C was found at the conservation region of TGM1 gene. Conclusion The mutations of R142C and R348X in TGM1 gene are present in the patient with lamellar ichthyosis.

Distraction osteogenesis for repair of cleft palate──Histological and fluorescent labeling study / 实用口腔医学杂志

Objective: To observe the mechanism and characteristics of new bone formation and remodeling process during distraction osteogenesis (DO) in the reconstruction of bone defect in cleft palate (CP). Methods: Sagittal palatal osteoectomy were performed in 12 cats to establish the CP model. The CP defects were reconstructed by intraoral distractors at the rate and rhythm of 0.4 mm?2/day till the transport disc (TD) reached the opposite edge across the defect region. Tetrachloride fluorescent labeling was administered 6 days before euthanasia specimen retrieval at 2, 4, 6, 8, 12 weeks through fixation period. Histological and fluoroscopical study were performed; control groups (2 animals in each group) were set for comparison. Results: The bone defect of CP was successfully reconstructed by DO. Exclusively intramembranous de novo osteogenesis were observed. Soft tissues attaching to TD were elongated simultaneously. No spontaneous repair was observed in control animals. Conclusion: With effective distraction and steady fixation, CP bone and soft tissue defect can be reconstructed by active intramembranous bone formation and remodeling following the applicaion of DO.