Abstract: Objective （ ） To investigate the current status of medical radiation protection in medical and health institutions MHI Methods - （ ） in Tibet Autonomous Region. Sixty one MHIs in seven prefectures cities of Tibet Autonomous Region were selected as the study subjects by stratified random sampling. The radiological protection equipment and personal protective ， equipment were investigated and the quality control of radiological equipment and radiation protection monitoring in Results ， radiological workplace were monitored. There were 368 radiation workers in 61 MHI institutions accounting for 4.8% （ ） ∶ ， 368/7 701 of the total number of radiation workers. The ratio of male to female was 2 1 and the average was six people/ institution. The quantity of radiation monitoring equipment and personal protective equipment at all levels of MHI was less than ， 1.00 sets/person. Among them tertiary MHI had the lowest number of personal protective equipment configurations. The （ monitoring qualified rates of radiation equipment quality control and radiation protection in radiation workplace were 73.3% 88/ ） （ ）， 120 and 95.8% 115/120 respectively. The lowes tmonitoring qualified rate of radiation equipment quality control was 55.2% （ ） ， （ ， ）Conclusion 32/58 with digital radiography and the second was computed tomography 84.8% 28/33 . The monitoring ， qualified rate of radiation protection in MHI workplaces at all levels in Tibet Autonomous Region is high. However radiation monitoring equipment and personal protective equipment should be increased.

Objective To investigate the anti-tumor effects of hydroxycamptothecin ( HCPT ) with different lactone ratios on the mice models of H22 hepatoma. Methods Mice models of H22 hepatoma were established. Tumor inhibiting rates of HCPT with different lactone ratios ( 0%, 25%, 50%, 75%, 100%) and the growth status of model mice before and after chemotherapy were observed. Serum biochemical indices were determined to investigate the effects of HCPT with different lactone ratios on hepatic and renal function of the mice. Results Positive control drug and HCPT with different lactone ratios all inhibited the tumor in mice with H22 hepatoma, the inhibition rate was 65. 30%, 12. 57%, 49. 23%, 75. 47%, 90. 06% and 93. 22%, respectively. Compared with the model control group, the living conditions of the mice in HCPT groups were improved. With increasing of lactone ratios, the hepatic injury was alleviated markedly, but the renal injury was aggravated. Conclusion There is a positive correlation between lactone ratios and its anti-tumor effect, and HCPT with 75% lactone can achieve preferable anti-tumor effect with less toxicity as compared with that with 100% lactone ratio.

Aged ; Female ; Humans ; Subclavian Vein ; abnormalities

Objective To evaluate the efficacy,safety and impact of recombinant human cytotoxic T lymphocyte-associated antigen (CTLA)-4 fusion proteins (rhCTLA-4Ig) on serum human tumor necrosis factor (TNF)-α and CX3CL1 in active rheumatoid arthritis (RA) patients.Methods Forty-four RA patients were treated with rhCTLA-4Ig and placebo.Clinical response was assessed by American College of Rheumatology (ACR) criteria and disease activity score in 28 joints (DAS28).The levels of serum TNF-α and CX3CL1 were determined in 44 RA patients and 20 healthy controls by enzyme-linked immunosorbent assay (ELISA).Comparisons between groups were performed by t-test or x2 test.Results At week 12,ACR20,ACR50and ACR70 responses in RA patients with rhCTLA-4Ig were achieved by 95％(20/21 ),76％( 16/21 )and 19％(4/21) respectively,but no patient with placebo achieved ACR20,ACRS0 and ACR70 responses.There were significantly statistical differences in ACR20 and ACR50 responses (x2=39.17,26.69,P＜0.01 ).At week 12,the mean DAS28 in the rhCTLA4Ig group was 3.1±1.3 versus 6.2±1.1 at baseline (P＜0.01).Similarly,health assessment questionnaire (HAQ) improved significantly,declining from 1.4±0.5 at baseline to 0.4±0.5 at week 12 (P＜0.01).However,the mean DAS28 in the placebo group was 5.8±1.2 versus 6.0±0.7 at baseline (P＞0.05),HAQ declined from 1.6±0.4 to 1.6±0.6 (P＞0.05).In addition,there were higher levels of TNF-α and CX3CL1 in the active RA patients than those of the healthy controls (P＜0.01).After 12 weeks therapy,Serum TNF-α and CX3CL1 levels in the rhCTLA-4Ig group decreased significantly (P＜0.01).There weren't decline in the placebo group (P＞0.05).Conclusion This study has shown that rhCTLA-4Ig is very effective in reducing disease activity,improving function during the 12 weeks treatment.rhCTLA-4Ig therapy for 12 weeks can lead to significant decrease of serum TNF-α and CX3CL1.

BACKGROUND: Recently biodegradable hydrogel has been extensively used to delivery anticancer drug and bioactive macromolecule. However, to protect the activity of the bioactive macromolecule, we need to obtain series of hydrogel which have milder hydrogelation conditions and shorter hydroglation time.OBJECTIVE: To prepare enantiomeric poly(L-Lactic acid) (PLLA)-poly(ethylene glycol (PEG)-PLLA/ poly(D-Lactic acid) (PDLA)-PEG-PDLA stereocomplex hydrogel which has shorter hydroglation time, to physically encapsulate a model drug-lysozyme and sustained release it from the hydrogel. METHODS: Triblock copolymers of PLLA-PEG-PLLA and PDLA-PEG-PDLA were synthesized by ring-opening polymerization of L(D)-lactide using PEG as the initiator and Sn(Oct)2 as the catalyst. The triblock copolymers were characterized by 1H nuclear magnetic resonance, FT-IR and X-Ray diffractometry. A hydrogel was prepared from an aqueous mixture of PLLA20-PEG227-PLLA20 and PDLA21-PEG227-PDLA21 (10 wt% concentration) at room temperature for 12 hours. X-Ray diffractometry test was used to research the gelation mechanism. The release profile of the lysozyme as a model drug from the hydrogel was tested. The morphology of the freeze-dried hydrogel was investigated by scanning electron microscope. The cytotoxicity of the hydrogel was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay.RESULTS AND CONCLUSION: Triblock copolymers of PLLA-PEG-PLLA and PDLA-PEG-PDLA were obtained. Both the PEG and PLA blocks in the copolymers could crystallize, but the crystallization of the PEG block was predominant. The stereocomplex formation between the PLLA and PDLA blocks within the hydrogel was confirmed by the X-Ray diffractometry analysis. The release profile of the lysozyme from the hydrogel exhibited a sustained-release pattern with a duration period of 7 days. The hydrogel exhibited a 3D interconnected porous structure with 50-100 μm pore size after being freeze-dried. The mouse fibroblast cell viability percentage was 99.3% after the cells contacted with the 100% extracted liquid for 72 hours.

BACKGROUND: Individual three-dimensional (3D) scaffolds can be constructed by 3D printing via Computer Aided Design based on the given anatomical measurements of related tissues. A rapid and accurate reconstruction of bone, cartilage, muscle and vessel also can be achieved by 3D printing; however, many problems still remain unsolved.OBJECTIVE: To summarize the principle and classification of 3D printing, the classification, characteristics and histocompatibility of scaffolds through reviewing the articles addressing 3D printing applied in bone tissue engineering,thereby providing theoretical foundation for the study on the construction of tissue-engineered bone.METHODS: PubMed and CNKI databases were retrieved for the literatures regarding the application of 3D printing technology in bone tissue engineering published from January 2001 to January 2017 using the keywords of three-dimensional printing, rapid prototyping manufacturing, bone tissue engineering in English and Chinese,respectively. Finally, 30 articles were reviewed and discussed in accordance with the inclusion and exclusion criteria.RESULTS AND CONCLUSION: The microstructures of normal tissues can be reconstructed and seed cells are printed on the 3D scaffolds synchronously by 3D printing technology. Moreover, the scaffold degradation and cell differentiation are synchronous, which contributes to tissue repair. Biological ceramics have been widely used in bone tissue engineering because of its good biocompatibility and mechanical properties. However, the urgent problems such as angiogenesis and cellular signal transduction still need to be addressed.

AIM: To study the isolation,expansion and purification of mesenchymal stem cells(MSCs) from human umbilical cord blood(UCB),and investigate some biological identities of MSCs.METHODS:(1) MSCs of UCB,adult bone marrow(BM) and fetus BM were isolated by centrifugation with Ficoll,and the different kinds of MSCs were observed everyday.(2) Surface markers of MSCs were identified by flow cytometry.(3) The level of HGFs(TPO,SCF,FLT-3L,IL-6) secreted by different sources of MSCs was checked by ELISA method.RESULTS:(1) No difference in morphology of the colonies between UCB MSCs and BM MSCs was observed.However,the mononuclear cells needed in culture of UCB MSCs was about 3 times more than that in culture of BM MSCs.The times of UCB MSCs colony formation and confluencing were longer than that of BM in primary culture.(2) After passaged,there was no significant difference in the proliferation rates of 3 kinds of MSCs.Only 4 of 15 UCB samples contained a homogeneous population of MSCs.(3) UCB MSCs shared the same markers with BM MSCs.Neither hematopoietic marker nor immunologic recognition antigens were expressed.(4) The level of hematopoietic growth factors(HGFs) secreted by 3 kinds of MSCs was similar.CONCLUSIONS:(1) MSCs were isolated from UCB,but the amount of MSCs in UCB was smaller than that in BM,and just seldom samples of UCB contained homogeneous MSCs.(2) MSCs from UCB and BM shared the same biological characteristics,such as proliferation ability,surface markers,immunophenotypes and HGFs secretion.

【Objective】To observe the efficacy and side effects of hematopietic stem cell transplantation with combination of umbilical cord blood(UCB) and neonatal peripheral blood(NPB) in the treatment of β-thalassemia major.【Methods】28 mL NPB was drawn from a HLA identical neonate within 5 hours after his birth to complement stem cell of the UCB he donated for transplantation to his sibling with β-thalassemia major.Various items of hematopoiesis reconstruction were detected in UCB and NPB respectively.After conditioning with chemotherapy by using busulfan 20 mg/kg,cyclophosphamide 200 mg/kg,melphalan 90 mg/m2 and antithymocyte globulin(ATG) 90 mg/kg,the patient received the 53 mL UCB and 28 mL NPB,achieving 5.7×107/kg nucleated cells(NC),93×105/kg CFU-GM and 3.1×105/kg CD34+CD38- cells from his HLA-identical sibling.【Results】Absolute nucleated cell(ANC) reached 0.5×109/L on 14th day post transplant,and platelets reached 20×109/L on 34th day after transplant.The heterozygosity of β-654 mutation point was detected by the PCR-RDB.The sexual chromosome changed from XX pretransplant to XY posttransplant.The patient was free red blood cell transfusion from 14th day post transplant.Her hemoglobin rose progressively from 86 g/L to 110 g/L.The patient survived for 197 days free from disease after transplantation.Following up for 9 months, the donor grew and developed normally.【Conclusion】The NPB contains a lot of stem cells.The transplantation with combination of suitable NPB and UCB is an effective tactics when the UCB cells are deficient.

MicroRNA has speciifc biological and expression properties in transcription level, which has more potential than genomic DNA in the identification for forensic body fluid, species and degraded crime biological materials. Here we introduce the speciifc research of forensic body lfuid identiifcation, research strategies and applied perspectives with forensic miRNA, expecting to provide the application and study of miRNA analysis for reference.