BACKGROUND:Articular cartilage has limited ability to repair itself, and the traditional means are difficult to repair articular cartilage defects, but articular cartilage tissue engineering provides new methods and approaches for large-area articular cartilage defects. OBJECTIVE:To review the current status, problems and prospects of tissue engineering technology in articular cartilage repair. METHODS:The retrieval of PubMed database was performed for articles published from 1982 to 2015, with the keywords of “articular cartilage, repair, tissue engineering” in English. Literatures related to tissue engineering repair of articular cartilage were included, but repetitive studies were excluded. Finaly 39 articles were reserved in result analysis. RESULTS AND CONCLUSION:Excelent seed cels have chondrogenic differentiation potential, and currently, the main seed cels for articular cartilage repair include mesenchymal stem cels, embryonic stem cels, adipose-derived stem cels and precartilaginous stem cels. Different growth factors, which can induce the in vivo growth of host parenchymal cels, improve seeded cel stability, and accelerate tissue regeneration, tend to be combined in clinical application. Composite scaffolds are also one of hot researches that can promote cell inoculation and spatial distribution as well as accelerate cell proliferation. To obtain the best effectiveness of articular cartilage repair, how to optimize seed cells, select and match scaffold materials to construct new types of composite patterns is an important direction in the future.

Objective: To establish a high performance liquid chromatography-tandem mass spectrometric method ( HPLC-MS/MS) method for the determination of PA-824 in the plasma of Beagle dogs, and study the pharmacokinetics of PA-824 in Beagle dogs. Methods:Carbamazepine was used as the internal standard, and the plasma samples were pretreated with ethyl acetate for the liquid-liquid extraction of PA-824. An Eclipse Plus C18 column (100 mm × 2. 1 mm, 3. 5 μm) was used with the mobile phase consisting of methanol-water (90 :10). The flow rate was 0. 6 ml·min-1 and the column temperature was 30 ℃. The injection volume was 5 μl and the sample analysis time was 5 min. The determination was performed with an electrospray ionization ( ESI) source in the positive multiple reaction monitoring (MRM) mode. The ion pairs were m/z 360. 1→m/z 175. 0 (collision energy of 35, solution cluster volt-age of 65) for PA-824 and m/z 237. 2→m/z 194. 0 (collision energy of 28, solution cluster voltage of 83) for carbamazepine. After the oral administration, PA-824 in plasma was measured at different time points, and then the pharmacokinetic parameters were calcu-lated by DAS 2. 0 software. Results: PA-824 showed a good linear relationship within the range of 50-10000 ng · ml-1 ( r =0. 9991). The recovery was 97. 7%-105. 1%, and the RSDs of intra-day and inter-day were less than 5. 0%. At three different dosa-ges (100, 200 and 500 mg) of PA-824, AUC0-twere (5735. 18 ± 1918. 76),(11548. 47 ± 1838. 04) and (21987. 88 ± 4587. 58) ng·min·ml-1,t1/2 were(14.17 ±5.97),(11.11 ±4.39) and (13.13 ±5.46)h,and Cmaxwere(626.66 ±188.48),(2399.13 ± 516.51) and (4861.33 ±2253.61)ng·ml-1, respectively. Conclusion:The method is simple, accurate, rapid and reproducible, and suitable for the pharmacokinetic study of PA-824 in the plasma of Beagle dogs.

Objective:To study the kinetics of transdermal absorption of volatile oil from Angelica slinesis in fetal skin and investi-gate the mechanism of penetration enhancement in terms of morphology. Methods: Franz diffusion cells were used to investigate the transdermal characteristics in vitro. The content of ligustilide was determined by HPLC, and the cumulative permeation amount per unit area and rate constant of ligustilide were calculated. The effects of volatile oil from Angelica slinesis on skin ultrastructure was observed by a scanning electron microscope and a transmission electron microscope. Results:The kinetics of volatile oil at different concentra-tions was all in accordance with Higuchi equations. The ultrastucture changes of fetal skin under the scanning electron microscope were as follows:the wrinkles on skin surface increased, some areas of stratum corneum peeled off and turnovered like worn-out cotton pad-ding, the follicular orifice was enlarged, and the cuticles of the hair shaft dropped off and became thinner. The changes of fetal skin ul-trastucture under the transmission electron microscope were as follows:stratum corneum cells peeled off, the cell junction in basal lam-ina and stratum spinosum were broken, and the intercellular space was enlarged. Conclusion: The volatile oil from Angelica slinesis has good transdermal permeability. Its enhancement mechanism of transdermal drug absorption is closely related with the effects on skin ultrastructure, which can change the structure of stratum corneum to increase the cell gaps resulting in enhancing drug penetration.

Objective To establish a method of quick three-dimensional (3D) reconstruction of pubic symphysis based on magnetic resonance imaging. Methods The pelvis images of adult male were generated on a 3.0 T scanner using a T1 Gradient Echo FLASH-3D (T1- FL3D) sequence and imported the images into medical image control system. Segmentation of binaryzation threshold was conducted and pelvic soft tissue image was extracted by regional growth, 3D structure model of pubic symphysis was obtained by Boolean operation. The 3D structure model of pubic symphysis was established by the noise reduction of reverse engineering software. And compared with the 3D reconstruction model pubic bone CT scan. Results The morphological characters of the MRI pubic symphysis 3D model, such as the ridges and furrows on the symphysial surface, lower extremity, dorsal margin (beveling), margin (beveling) and pubic tubercle, were highly consistent with the morphological characters of the 3D model established by CT scan. Conclusion MRI scan can be used to reconstruct the 3D structure of pubic symphysis quickly and effectively, and it can provide a safe radiation-free 3D visualization imaging technique for forensic age estimation for the living.

Objective To study the absorption characteristics of promethazine hydrochloride in different parts of rat intestine, provide evidence for the development of new preparation. Methods Rat single-pass intestinal perfusion model was established. By using high performance liquid chromatography (HPLC), 25, 50, 100 μgmL-1 promethazine hydrochloride concentration changing in different parts of the intestine was detected. Through the relevant calculation, the absorption rate constant ( Ka ) , and the apparent absorption coefficient ( Papp ) were obtained. Results With the concentration increase of promethazine hydrochloride in duodenal and ileal segments, the Ka and Papp increased significantly in the same part. Ka was (28.00±0.02)×10-2min-1 and Papp was (9.64±0.22) in the jejunum were the highest when the promethazine hydrochloride concentration was 50 μgmL-1 . As the concentration increased in colon, there were no significant changes in Ka and Papp . Conclusion Promethazine hydrochloride is absorbed in various intestinal segments, most obviously in duodenum and ileum, the absorption order is duodenum>ileum>jejunum>colon. Promethazine hydrochloride is absorbed most in the small intestine, in line with the intestinal absorption characteristics.

Standardized residency training is the only way for medical students to grow into clin-icians. At present, the number of under training residents in China has reached 190000 (excluding special-ized degree graduate students). It is very important to manage each stage of this training well, which is an guarantee for improving the effect of standardized training. The residents who attend the training are com-posed of "unit personnel" and "intra-industry social personnel", and after standardized and homogenized training, the two types of students have officially become the new force in the medical industry after passing the final examination. In order to do a good job in the management of standardized residency training, to achieve fine management at all stages , this paper focuses on the differences between the two types of students, analyzes in detail the characteristics of these two types of students in the recruitment, training and welfare guarantee stages. "Unit personnel" are given the security, supervision and containment of the origi-nal unit, while due to the pressure of job-hunting and the uncertainty of future welfare, "intra-industry so-cial personnel" are equipped with more initiative. Based on advanced management experience in Beijing,Shanghai, Sichuan and Tianjin, this paper aims to summarize the key points in management of the two types of students in training, propose countermeasures to the difficulties in management, innovative management solutions, and provide reference for the optimization management of standardized residency training.

Pharmacotherapy is the primary treatment method for hyperthyroidism. Antithyroid drugs can induce liver injury， and the diagnosis of drug-induced liver injury is mostly exclusive based on medical history collection， clinical symptoms， serum biochemistry， radiological examination， and histology. According to the severity of liver injury， drug-induced liver injury can be classified into mild， moderate， severe， and fatal degrees. Drug withdrawal may not be necessary for patients with mild liver injury， but regular monitoring of liver function is required； in severe cases， patients may develop liver failure， which may lead to a mortality rate， and early identification， timely drug withdrawal， and reasonable pharmacotherapy can help to avoid fatal consequences. The treatment principles of liver injury induced by antithyroid drugs include promoting the recovery of liver injury， preventing the severe exacerbation and chronicity of liver injury， and reducing the risk of death. Standardized medication， timely monitoring， early identification， and early treatment are important measures for the prevention and treatment of liver injury induced by antithyroid drugs.