BACKGROUND:Mesenchymal stem cells have been an important source of seed cells for tissue engineering, regenerative medicine and immunosuppressive therapy areas. The large expansion is the key to the clinical application of mesenchymal stem cells. OBJECTIVE:To summarize the research progress in the in vitro expansion of human mesenchymal stem cells in animal serum-free media. METHODS:A computer-based online retrieval of CNKI and PubMed databases was performed to search papers published between 2004 and 2014 using the key words of“mesenchymal (stromal) stem cells, animal serum-free media, humanized media, human serum, umbilical cord blood serum, platelet rich plasma, platelet lysate, defined medium”in English and Chinese, respectively. Final y, 41 articles were retained. RESULTS AND CONCLUSION:Human serum, umbilical cord blood serum, platelet rich plasma, platelet lysate and defined medium can replace fetal bovine serum for large-scale expansion of mesenchymal stem cells in vitro. These media or additives have their advantages and disadvantages;therefore, it is urgent to guarantee the functional effectiveness and transplantation safety before large-scale, systematic clinical application of mesenchymal stem cells.

BACKGROUND:Platelet lysate has been known as a kind of lysate of autologous or alogeneic platelet-rich products. It not only removes the residual cel structure, reduces immunogenicity, but also retains many growth factors. Platelet lysate has been suggested as a substitute for fetal bovine serum to expand mesenchymal stem cels in vitro. OBJECTIVE:To observe the effects of platelet lysate on biological characteristics of human bone marrow mesenchymal stem cels and adipose mesenchymal stem cels, and provide some experimental data for clinical cel therapy and regenerative medicine. METHODS:Platelet lysate was prepared by repeated freezing and thawing from fresh blood. Healthy adult bone marrow and adipose tissue were colected. Human bone marrow mesenchymal stem cels and adipose mesenchymal stem cels were obtained by density gradient centrifugation and type I colagenase digestion. We tested the morphology, cel phenotype, differentiation characteristics, proliferation capacity, colony forming ability and the level of cytokine secretion of bone marrow mesenchymal stem cels and adipose mesenchymal stem cels after cultured with platelet lysis. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cels and adipose mesenchymal stem cels were successfuly cultured in vitro using platelet lysate. There were no significant differences in morphology, cel phenotype, colony forming ability and the level of cytokine secretion, and chondrogenic, osteogenic and adipogenic capacities between bone marrow mesenchymal stem cels and adipose mesenchymal stem cels. Adipose mesenchymal stem cels had a high cumulative population doublings than bone marrow mesenchymal stem cels (P < 0.05). These findings suggest adipose mesenchymal stem cels had a stronger proliferative ability, and are more suitable for large-scale expansionin vitro cultivation system of platelet lysate compared with bone marrow mesenchymal stem cels.

Objeetive To study the application of template in intensity modulated radiotherapy (IMRT)planning.Methods With Philips Pinnacle3(R) version 7.6c treatment planning system(TPS) platform.a template for left breast cancer's IMRT planning was customized by using the function of scripting.Ten patients received IMRT alone after breast-conserving surgery were selected,two IMRT plans were designed for each patient:individual plan and the plan based on the template.Dose parameters of target,including conformal index(CI)and homogeneity index(HI),dose-volume histogram parameters,including V30,V20 of lung and cardiac,and the planning time were compared respectively.Results Of the two IMRT plans based on the template method and individual method.The average time of design an IMRT plan were 7±0.82 min and 36.5±6.84 min(t=13.55,P=0.000),the PTV average CI were 0.851± 0.015 and 0.845±0.032(t=0.59,P=0.560),the PTV average HI were(13.2±1.3)%and(14.4±1.6)%(t=1.804,P=0.08),the lung average V30 were(8.80±0.53)%and(8.31±0.74)%(t= cardiac average V30 were(9.89±1.14)%and(9.66±1.43)%(t=0.41,P=0.688).Conclusion For the tumor with the same location and stage,the application of template can simplify planning process and reduce working time,which was worthy of expansion.

Objective:To analyze the job preference of doctors at township health center ( THC) and provide references for formulating effective policy. Methods:238 cases of doctors were sampled from Shandong, Anhui and Shaanxi provinces. Using a discrete choice experiment, we analyzed the data with a conditional logit model. Results:The most important job attribution was salary, followed by education for children, permanent post, work location, training opportunity, and years before promotion. The OR value of the monthly income of 8 000 yuan is 7. 0 compared to 2 000 yuan. Doctors will pay 3 857 yuan and 3 294 yuan respectively for better education for children and perma-nent posts. Monthly income increasing to 8 000 yuan will reduce the quitting rate from 35% to 8%, and providing better education for children and permanent posts will reduce 5%. The permanent posts at township health center and non-permanent posts in county hospital have the same appeal to the doctor. Conclusion:When choosing a job, doc-tors at THCs valued salary the most. Improving the education level for children can be beneficial for attracting and re-taining doctors at THCs. A permanent post is more attractive to doctors than non-permanent posts at THCs.

Glycogen synthase kinase-3β( GSK-3β) is a serine-threonine kinase,which was originally identified as a key regula-tor of glycogen metabolism. In nervous system, GSK-3β partici-pates in many central and peripheral nervous system physiological processes through transcription,cell proliferation and differentia-tion. The abnormal activity of GSK-3βinduces downstream signa-ling molecules and gene expression abnormalities,which are in-volved in some neuropsychiatric disorders such as schizophrenia, bipolar disorder,Alzheimer's disease,and pain. In recent years, lots of basic and clinic researches focus on GSK-3β,which might gradually become critical theraptic target of many diseases. The article mainly reviews the mechanisms involved in abnormal acti-vation of GSK-3β related neuropsychiatric disorders.

Objective To develop a beam orientation optimization algorithm for the gantry orientation in three-dimensional conformal radiotherapy(3 DCRT).Methods Patients' data were imported from the Pinnacle v 7.2 treatment planning system.including the DICOMRT and dose distribution files.These imported files were merged using a uniforiB coordinate system.The algorithm determined the optimized beam weight for each beam group and optimized the beam orientation with genetic algorithm.The optimized parameters,including the optimized beam orientations and weights,were exposed back to the Pinnacle v 7.2 to compare with the conventional 3DCRT plan.The optimized algorithm was implemented with our in-house program. The dose distributions, the DVH diagram and the conformity index of two lung cancer patients were compared. Results for the two lung cancer patients,the conformity index of the optimized plan(0.59 and 0.7)was higher than the conwentional 3DCRT plan(0.36 and 0.58).The maximum dose in spinal cord was reduced by 17.8%and 22.4%,the lung V20 reduced by 3.12%and 4.35%,and V30 reduced by 4.47%and 1.49%.For the brain tumor patient. the dose of lens and eyes was also decreased significantly. Conclusion This beam orientation optimization can be used as an assistant planning tool.

Objective To study the application of correlation statistical analysis model in IMRT planning optimization. Methods A correlation statistical analysis model was established. IMRT plans of 5 prostate cancer patients were randomly chosen from the ADAC Pinacal 7.6 version planning system. The beam parameters, objective functions of the target area and optimization parameters of the primary plan were kept unchanged. The main optimization parameters including EUD parameter a,weight (w) and EUD_(max) of OAR were adjusted in optimization procedure successively. The correlation analysis (CF) and optimization efficiency analysis (OF) were carried out on the results of the optimization. The optimal value of parameters (MORt{}) with the best dose distribution was obtained and substituted in the corresponding primary plan.After optimization, the dose distributions of the two IMRT plans were compared. Results There were signif-icant differences with different optimization methods. The EUD parameter a and weight factor (w) almost had no effect on volume dose of OAR (OF < 0.01), though had obvious effect on the maximum dose and mean dose (OF≈1). The CF analysis showed that the correlation between the PTV ( V_(95)) volume and OAR dose was different when the EUD parameter a and w were applied for optimization. Meanwhile, the difference was proportional to the distance between the target area and OAR. The mean dose of OAR was decreased and the mean dose of PTV was more close to the prescription dose when the optimization parameters of the prima-ry plan were substituted with MOR{a} ,MOR{w} and MORt{EUD_(max)}. Besides, the DVH and isedose dis-tribution of the secondary plan were better. Conclusions The correlation statistical analysis model can be used to accurately determine the scope of optimization parameters in the IMRT planning procedure in prostate cancer, and an IMRT plan which fulfils the clinical requirement can be obtained efficiently.

Objective To study the dosimetry of mono isocenter irradiation technique in radiotherapy for nasopharyngeal carcinoma. Methods Conventional and mono isocenter irradiation techniques were used to simulate irradiation of the phantom and nasopharyngeal carcinoma patients with Siemens primus linear accelerator equipped with asymmetric collimators. Dose uniformity?isodose distribution and field overlap were measured at the plane of junction with TLD and film dosimeter on the phantom. The reproducibility of the set up was tested on patients with verification films. Results For an applied dose of 1?Gy, TLD dosimetry showed that the mean dose at the junction of fields were 1.01 ?Gy for the mono isocenter technique as compared to 1.09 1.13?Gy for the conventional technique. An ideal isodose distribution at the junction with mono isocenter technique was found by film dosimetry. The reproducibility of the set up was obviously better for the mono isocenter technique, with less field overlap (1mm) and set up deviation (0.5?mm) than those (6 14?mm and 3?mm) of the conventional technique. Conclusions This investigation of junction dosimetry confirms the potential advantage of the mono isocentric technique. Not only does it lead to superior dosimetry in the plane of junction but also associates with a better reproducibility of the set up.

Objective To evaluate the methods of carrying out radiotherapy quality control (QC) and quality assurance (QA) in the whole province. Methods From 1995, radiotherapy quality control center of Zhejiang province (the guiding team consists of specialists in radiation oncology of the province) has carried out a QC and QA program including evaluation of administration, departmental infrastructure, equipment, staff and treatment for 28 centers in the whole province. The regulation and scoring system were designed and first informed to every center, with the 28 centers checked and examined by the guiding team from 1999 to 2000. Results Great variations in equipment and staff were observed among participating centers. Equipment condition was not very satisfactory. Most of the treatment protocols were reasonable except that the indication for radiotherapy was not strict enough in some centers. Conclusions It is feasible for the radiotherapy quality control center to check and examine the department of radiation oncology in the whole province. Good QC and QA is invaluable to standardize the treatment protocol and ensure the radiotherapy quality and also helpful to carry out multi center study in the future.

Objective To evaluate the efficacy of percutaneous CT guided interstitial 125Ⅰ seeds implantation treatment for refractory pelvic malignant tumors and discuss the procedure of technique.Methods Twenty-three patients with refractory pelvic malignant tumors(25 lesions,diameter 3.5-7.0 cm,mean 4.5 cm) showing failure response to full chemotherapy and/or radical radiotherapy after tumors resection were undergone percutaneous CT guided intratumoral 125Ⅰseed implantation.Treatment plan system(TPS)was used to design the distribution and number of 125Ⅰ seeds according to matched peripheral dose(MPD)1-3 days before the procedure.Of which 6 cases received combined internal iliac arterial infusion chemotherapy before or after the 125Ⅰ seed implantation procedure.Results 9 ～ 75(mean 27)125Ⅰ seeds were implanted into a single tumor at first time including 6 patients with intraarterial chemotherapy for 14 cycles(mean 2.3 cycles),showed relief of clinical pain symptoms in 16 of 23 cases,72 h ～ 4 w after the seeds implantation;with the an effective rate of 69.6%.Follow up for 2-34 months(median,21 months),CT or MRI performed 2 months after the seeds implantation showed no CR,but PR in 18 cases,SD in 4 cases,and PD in 1 case,with overall response rate of 78%(18/23),and no serious complication.In addition,20 cases survived,with the longest one of 34 months and the other 3 died.Conclusions Intratumoral 125Ⅰ seeds implantation under CT guidance for pelvic refractory malignant tumors is safe,minimally invasive,and effective.