Construction of C-shaped cartilage with electrospun gelatin/polycaprolactone nanofibrous membranes and 3D printed supporter / 上海交通大学学报（医学版）

Objective·To construct C-shaped cartilage rings by rabbit auricular cartilage-derived chondrocytes combing with both electrospun gelatin/ polycaprolactone(GT/PCL) nanofibrous membranes and 3D printed supporters for repairing tracheal cartilage defects.Methods·Primary chondrocytes were isolated from rabbit auricular cartilage with methods of trypsin enzyme digestion and collagenase enzyme digestion.After proliferation in vitro,the chondrocytes of passage 2 were harvested for further experiments.Ultrafine composite fibers of GT/PCL were fabricated via electrospinning.The electrospun GT/PCL membranes were tailored into rectangle shape,the length of which is 12 cm and the width is 2.5 cm.Chondrocytes were seeded on membrane at a density of 1 × 108 cells/mL.Then the membrane were rolled onto a 3D printed supporter of poly(DL-lactide-ε-caprolactone) (PLCL) material to construct a C-shaped cartilage-like complex.After 8 weeks of subcutaneous incubation in vivo,gross inspection and paraffin section staining were applied for evaluation.Results·After 8 weeks of culture in vivo,mature cartilage-like tissue were formed with open-cylindrical bellow appearance and pecific mechanical property.C-shaped rings arranged at regular intervals on the inner surface of tissue,which were similar to the normal structure of tracheal cartilages.Histological and immunohistological staining showed a large number of typical lacunar structures and extracellular matrix secretions.Conclusion·It is feasible to construct tissue engineered C-shaped cartilage tissue by combing chondrocytes with GT/PCL membrane and 3D printed PLCL supporter for tracheal cartilage repair.

Determination of 7-ethyl-10-hydroxycamptothecin in microdialysates from rat brain with LC-MS/MS / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish a method for determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in microdialysates from rat brain.</p><p><b>METHODS</b>The concentrations of SN-38 were measured by LC-MS/MS method with Agilent Eclipse Plus C18 (2.1 mm ×100 mm, 1.8 μm) reversed phase column using acetonitrile-0.1% methanoic acid as mobile phase with gradient elution at a flow rate of 0.3 ml/min and temperature at 35 degree. Multiple reaction monitoring using the precursor to product ion combinations of m/z 393.1→349.1 was performed to detect SN-38 in microdialysates from rat brain.</p><p><b>RESULTS</b>Blank microdialysate had non-interference. The method was linear over the concentration range of 0.1015-1015 ng/ml (r=0.9995); and the lower limit of quantification (LOQ) was 0.1015 ng/ml. The recovery of assay for SN-38 ranged from 97.54%-100.60%. The intra- and inter-day precision and stability were both well. The concentrations of SN-38 in brain microdialysates presented pharmacokinetics process and achieved the peak after 220 min.</p><p><b>CONCLUSION</b>The fully validated LC-MS/MS analytical method has high specificity and sensibility, which can be used effectively to analyze SN-38 in microdialysates from rat brain.</p>

Pharmacokinetic evaluation of danshensu with in vivo microdialysis in freely moving rat's jugular vein / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the pharmacokinetics of Danshensu with in vivo microdialysis in freely moving rat's jugular vein.</p><p><b>METHOD</b>three days after a microdialysis probe introducer was implanted into the jugular vein, a microdialysis probe was introduced to the blood vessel, and began to sample following a single intravenous injection (40 mg x kg(-1)) or a single oral dose (40 mg x kg(-1)) of Danshensu. All the samples were analyzed with HPLC. The concentration of Danshensu in blood were calculated according to the recovery of microdialysis probe and the concentration in dialysates. Pharmacokinetic parameters were than calculated with the concentration-time curve.</p><p><b>RESULT</b>For intravenous administration, t(1/2 zeta) = (69.62 +/- 33.42) min, AUC(0-infinity) = (3416.24 +/- 779.80) min x mg x L(-1), MRT(0-infinity) = (38.15 +/- 8.61) min, and for oral administration, Cmax = (7.42 +/- 3.08) mg x L(-1), tmax = (31.50 +/- 8.57) min, t(1/2 zeta) = (83.25 +/- 37.35) min, AUC(0-infinity) = (793.19 +/- 101.32) min x mg x L(-1), MRT(0-infinity) = (125.89 +/- 58.27) min. The oral bioavailability of Danshensu F = 22.56%.</p><p><b>CONCLUSION</b>In vivo microdialysis in freely moving rat's jugular vein is a useful tool to obtain a complete set of free drug concentrations to determine reliable pharmacokinetic parameters.</p>

Soring the sleep stages of rat based on the gravity frequency and complexity measure / 中国药理学通报

AIM To compare the new methods which can be used fo r soring the stages of rat sleep. METHODS Cortical EEG and hippocampal potential(HP) were collected by implanted electrodes in freely moving rats. Gravity frequency (f g) and the complexities(Kc,C 1), were calculated. According to the characteristics of each stage and by studying the histogram of f g, Kc and C 1, the stages of rat sleep were distinguished. RESULTS The methods of f g, Kc and C 1 can distinguish the Waking, nonrapid eye movement(NREM) and REM sleep well. Comparing the results of visual and our analysis, the rate of accordance is above 85%, and the analysis based on the complexity measure is more believable than that based on the f g. CONCLUSION The gravity frequency and the complexities of Kc,C 1 can be used to distinguish the different stages of rat sleep.

Development of a computerized automatic identification system for use in cephalometry / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish the automatic X-ray cephalometric analysis system to simplify cephalometric steps and to provide a convenient and reliable method for cephalometric analysis.</p><p><b>METHODS</b>The system which was programmed by visual-c language, and graphics and image processing techniques and artificial intelligence were used. The techniques related to computer digital image processing and pattern recognition such as Median filtering, Histogram equalization, Laplacian and Canny edge detection were introduced. It could automatically outline the contour lines of the hard and soft tissues by establishing the templates of the variable anatomical structures.</p><p><b>RESULTS</b>The following functions were established: (1) automatically outlining the contour lines of the soft tissues. (2) automatically recognizing, measuring and analysing the landmarks of soft tissues. (3) automatically recognizing porion, sella and the landmarks of the mandible. (4) automatically building the contour lines of the hard tissues. In brief, the system used the more advanced methods, calculated more precisely and saved more time and energy than other systems.</p><p><b>CONCLUSION</b>The system is a more convenient and precise tool in cephalometry.</p>