Three-dimensional finite element analysis on the novel locking plate and AO-PHILOS plate for fixing four-part proximal humeral fractures / 医用生物力学

Objective To compare biomechanical performance of four-part proximal humeral fractures fixed by novel locking plate or by AO-PHILOS plate. Methods The finite element fixation models of both the novel locking plate and AO-PHILOS plate for four-part proximal humeral fractures were established, respectively. The maximum Von Mises stress and displacement under 4 different functional positions of shoulder abduction in the two fixation models were compared by finite element analysis. Results The maximum displacement in shoulder abduction of 0°,30°,60°,90° were 6.644, 7.079, 5.850, 3.005 mm, respectively, in novel locking plate fixation model, and 6.293, 6.826, 5.774, 3.023 mm, respectively, in AO-PHILOS plate fixation model. Since the maximum displacements in both fracture fixation models were similar, it indicated that there was no significant difference in the stability for fixing proximal humeral fracture. The maximum Von Mises stress in shoulder abduction of 0°,30°,60°,90°were 1 033.0, 904.1, 888.1, 1 062.0 MPa in novel locking plate fixation model, while in AO-PHILOS plate fixation model, it showed 743.1, 692.4,486.4,393.5 MPa, respectively. During the process of shoulder abduction, the total stress in both fracture fixation models gradually decreased, but the new locking plate decreased in a larger range, showing an obvious stress dispersion. Conclusions Both the novel locking plate and AO-PHILOS plate can be used as internal fixation treatment for complex four-part proximal humeral fractures with no significant difference in stress distribution, and both showing a stable fixation effect. For fixing proximal humeral fractures with osteoporosis combined with the great and less tuberosity, the novel locking plate has an advantage over AO-PHILOS plate due to its unique anatomical wings and better fixing effect.

Mutations in the ED1 gene in families with X-linked hypohidrotic ectodermal dysplasia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To detect mutations in the ED1 gene in two Chinese pedigrees and a sporadic case with X-linked hypohidrotic ectodermal dysplasia (XLHED) and provide evidences with the mutation analysis for genetic counseling, prenatal diagnosis and confirmation of carrier status.</p><p><b>METHODS</b>Peripheral blood samples were obtained from two pedigrees and the sporadic patient, and genomic DNA was extract by salting out method. Polymerase chain reaction (PCR) and direct sequencing were performed to screen mutations in ED1 gene.</p><p><b>RESULTS</b>Three mutations were identified. In one of the pedigrees, a 1045G > A transition was evidenced in exon 9 that resulted in a change of Ala 349 Thr. In the other pedigrees and the sporadic patient, 467G > A and 466C > T transitions were demonstrated in exon 3 that resulted in change of Arg 156 His and Arg 156 Cys. These mutations were not found in 100 normal individuals.</p><p><b>CONCLUSIONS</b>These mutations were responsible for the disease in the two families and the sporadic patient. All these mutations had been identified previously.</p>

Pharmacokinetics and distribution of superoxide dismutase liposomes in rats / 药学学报

<p><b>AIM</b>To evaluate the effects of surfactants on the pharmacokinetics and distribution in rats after intravenous administration of SOD liposomes.</p><p><b>METHODS</b>The liposomes were prepared by reverse phase evaporation method. The activity of SOD was assayed by method of xanthine oxidase.</p><p><b>RESULTS</b>The T1/2 of SOD solution, common SOD liposome, SOD liposomes modified by DSPE-PEG2000 and Tween 80 were 0.25, 0.34, 0.66 and 0.41 h, respectively; AUC were 12.48, 24.66, 41.16 and 33.02 microg x h x mL(-1), respectively. Compared with the common liposome, the liposomes modified by DSPE-PEG and Tween 80 decreased the content of SOD in liver and spleen, but increased in brain.</p><p><b>CONCLUSION</b>The three kinds of liposomes could increase T1/2 and AUC in some extent, especially in PEG-L group. Tween-L could increase the SOD content in brain, and PEG-L could decrease the SOD content in the liver and spleen compared with the common liposome.</p>

In vitro and in vivo pharmaceutical behaviors of lycopene microcapsules / 药学学报

<p><b>AIM</b>To evaluate in vitro release of lycopene microcapsules. Pharmacokinetic parameters of lycopene microcapsule and lycopene powder as reference were estimated after a single dose of oral administration to dogs. The relationship between in vitro dissolution and in vivo absorption was investigated.</p><p><b>METHODS</b>The content of lycopene in the release medium was determined by UV spectroscopy method. Health hybrid male dogs were used as experiment subjects and lycopene powder used as standard to estimate the pharmacokinetics of lycopene microcapsules. HPLC method was used to assay the concentration of lycopene in dog plasma. Pharmacokinetics parameters were estimated by 3P87 program. The drug release percentage in stimulated intestinal fluid was compared with the absorption at a given time point.</p><p><b>RESULTS</b>The release profiles of lycopene from microcapsule showed that the lycopene gelatin microcapsule exhibited enteric property. The pharmacokinetics parameters estimated after oral administration of lycopene powder and lycopene microcapsule in a single dose of 2.5 mg x kg(-1) body weight to dogs were 7.30 h, 15.06 h for T1/2alpha; 28.10 h, 46.76 h for T1/2beta; 22.32 h, 41.03 h for T(max); 1.67 microg x h x L(-1), 2.08 microg x h x L(-1) for AUC(0-infinity), respectively. The concentration-time curves could be fitted to a two-compartment model for both the lycopene powder and the lycopene microcapsule analyzed by 3P87 program. The relationship between in vitro dissolution and in vivo absorption was found to have good correlation (r = 0. 981 9) was found.</p><p><b>CONCLUSION</b>It could be concluded that lycopene microcapsule was a sustained release dosage form. The result of release in vitro could be used to predict the absorption in vivo.</p>

The bonding characteristic of titanium and RG experiment porcelain / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the bonding characteristic of Titanium and RG experiment porcelain.</p><p><b>METHODS</b>5 specimens with a size of 10 mm x 5 mm x 1.4 mm were cast from pure titanium. Then 1 mm of RG experiment opaque and body porcelain were fused on the surface of the titanium specimens. The interface of titanium and porcelain was analyzed with a scanning electron microscope with energy-despersive spectrometry; 6 metal specimens with the size of 25 mm x 3 mm x 0.5 mm were cast from Ni-Cr alloy and a uniform thickness of 1 mm of VMK 99 porcelain was veneered on the central area of 8 mm x 3 mm 18 metal specimens as the same size were cast from pure titanium. The uniform thickness of 1 mm of VITA TITANKERAMIK porcelain, of Noritake super porcelain Ti-22 and of RG experiment porcelain were veneered on every 6 specimens respectively in the central area of 8 mm x 3 mm. The specimens were subjected to a three-point bending test on a load-test machine with a span of 20 mm, then the failure loads were recorded and statistically analysised. The RG porcelain/titanium crown was fabricated by fusing RG opaque porcelain and body porcelain to cast titanium substrate crown.</p><p><b>RESULTS</b>The SEM results show no porosity and crackle were found in the interface. The energy-dispersive spectrometry show that there are Si, Ti and O in the 1 micro m layer between porcelain and titanium, which suggesting titanium and experiment porcelain bonding well. The three point test showed the fracture force for the combinations of titanium/VITA TITANKERAMIK porcelain, titanium/Noritake super porcelain Ti-22 and titanium/RG experiment porcelain were (7.233 +/- 2.539) N, (5.533 +/- 1.199) N and (6.316 +/- 1.433) N respectively. There were not statistically significant differences among them (t test, P < 0.01). The fracture force for the Ni-Cr alloy/VMK99 porcelain combination (12.733 +/- 3.297) N was significantly greater than those of the cast titanium/porcelain (t test, P > 0.05). The crown was translucent with no crack.</p><p><b>CONCLUSION</b>RG porcelain is well compatible with titanium.</p>