[Clinical application and accuracy of the genioplasty surgical templates system for osseous genioplasty].

Objective: To develop and validate a new genioplasty templates system for monoblock osseous genioplasty. Methods: Thirty-six patients with chin deformities were enrolled in this study. The chin template system included a cutting guide and a repositioning guide for a genioplasty. Chin templates were designed in a computer and fabricated using a three-dimensional printing technique. The accuracy of the genioplasty templates were assessed by comparing the actual postoperative outcomes with the virtual plan. Results: All genioplasty was successfully completed by the template system. The largest linear root-mean-square deviation(RMSD) between the planned and the postoperative chin segments was 1.16 mm and the largest angular RMSD was 3.06°. Conclusions: The results showed that the chin template system provides a reliable method for transfer of genioplasty planning. The operation precision of the genioplasty can be improved by using the surgical templates system.

Rapid colorimetric pyrazinamide susceptibility testing of Mycobacterium tuberculosis.

SETTING: Colorimetric methods for detecting drug resistance in Mycobacterium tuberculosis are very attractive, as they are cheap, easy to use and require no costly apparatus. Although the current colorimetric methods have been used for other drugs, such as rifampicin and isoniazid, few of the colorimetric methods have been reported to have been used in performing drug susceptibility testing (DST) against pyrazinamide (PZA). OBJECTIVE: To develop a rapid and reliable colorimetric method for PZA DST using a monotetrazolium redox dye, 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), as indicator of viability. DESIGN: A total of 50 clinical isolates and three standard strains were tested using this colorimetric method and the BACTEC™ MGIT™ 960 system. RESULTS: Initial test results showed that the PZA DST results were available in 4-6 days; the overall sensitivity and specificity of the CTC colorimetric method were respectively 97.1% and 81.3% in comparison with the MGIT 960 results. CONCLUSION: These results suggest that the CTC colorimetric method is most rapid among the current PZA DST methods based on culture, and could be used for determining susceptibility to PZA of M. tuberculosis isolates.

Synthesis and pharmacokinetic evaluation of novel N-acyl-cordycepin derivatives with a normal alkyl chain.

For slowing down the too fast metabolic velocity and increasing the bioavailability of cordycepin, four N-acyl-(propionyl-, octanoyl-, lauroyl- and stearoyl-) cordycepin derivatives were synthesized chemically and their pharmacokinetic profiles were investigated in this study. The results show that time of maximum concentration (T(max)) and half-life (t(1/2)) would be elongated with the increase of the alkyl chain length, but maximum concentration (C(max)) and area under concentration-time curve (AUC) increased initially, then decreased when the number of alkyl carbon exceeded eight. The T(max), C(max) and AUC of N-octanoyl-cordycepin were nearly 4, 30 and 68 times, respectively, higher than that of cordycepin. All derivatives could be transformed into cordycepin in vivo and the concentration of transformed cordycepin was proportional to that of derivatives. It indicated that N-octanoyl modification could decrease the metabolic velocity and increase the bioavailability of cordycepin to the maximum, thus it might be a promising prodrug of cordycepin.