[Objective]To explicate whether the telomerase activity is regulated by human telomerase reverse transcriptase (hTERT) in human bone marrow mesenchyme stem cells(hBMSC).[Method]hBMSC were cultured and transfected with eukaryotic expressing plasmid pCIneo-hTERT encoding hTERT. After selection with G418 to stabilize the transfection,expression of hTERT mRNA was detected with TR-PCR, detecting the expression of hTERT protein was detected with Western Bolt, and the telomerase activity in untransfected and transfected cells were detected by RT-PCR.[Result]The hMSCs grew well after transfecting plasmid pCIneo-hTERT.The cells began to suspend and die after the day of the G418 selection. At the tenth day,all the untransfected cells were dead, but the transfected cells began to clone proliferation. So the density of G418 subdued to 100 ?g/ml for maintaining selecting, at the twentieth day,there were obvious anti-G418 cell clones. After stable transfection, hTERT was expressed at mRNA and protein level in these anti-418 cell clones, and meanwhile telomerase activity was positive and obviously raise up in these transfected cells.[Conclusion]In human' bone marrow mesenchyme cells,telomerase could be activated by exogenous hTERT. This is a foundation to establish immortalized human bone marrow mesenchyme stem cell line.

Objective To examine the segmental bone defects healing by ? TCP/rhBMP 2 composites with different degradation rate and discuss the relationship between osteogenesis and degradation of ? TCP in vivo. Methods Three kinds of ? tricalcium phosphate(? TCP) with different degradation rate (? TCP1-3) were prepared by means of different techniques. ? TCP/rhBMP 2 composites with different degradation rate(? TCP1/rhBMP 2 and ? TCP2/rhBMP 2)were obtained by combining ? TCP1, ? TCP2 with recombinant human bone morphogenetic protein 2(rhBMP 2), respectively. ? TCP1/rhBMP 2, ? TCP2/rhBMP 2, ? TCP1, ? TCP2 and ? TCP3 were used to repair 15 mm radial segmental defects in 81 Chinese rabbits. When the samples were harvested in 4, 8, 16 and 24 weeks after surgery, a series of examination were carried out, including the roentgenographical, histomorphological, biomechanical and computerized graphical analysis, energy dispersion analysis X ray (EDAX), and measurements of inorganic contents. Results Roentgenographically and histologically, all of the defects that had been treated with implants exhibited new bone formation, increasing with time. The quantity and rate of new bone formation in ? TCP1/rhBMP 2 group and ? TCP2/rhBMP 2 group were higher than those in group of ? TCP alone. The ability of new bone formation in ? TCP1/rhBMP 2 group was strongest. At 24 weeks the defects in ? TCP1/rhBMP 2 group were bridged with the appearance of marrow cavities, the inorganic contents and ratio of calcium to phosphate and biomechanical property in implants approached to those of normal bone. Although degradation occurred to some extent in ? TCP alone the degradation were faster in ? TCP/rhBMP 2 composites. At 24 weeks the degradation rate in ? TCP1/rhBMP 2 group and ? TCP2/rhBMP 2 group were 97.4%and 73.4%, respectively. The defects in blank controls were repaired only by fibrous tissue at 24 weeks. Conclusion ? TCP/rhBMP 2 composites with different degradation rate could repair segmental bone defects, and osteogenesis could accelerate the degradation of ? TCP in vivo.

2 months were selected. Anthropometric measurements, laboratory examinations and dietary surveys were used to assess the nutritional status. ResultsBody weight(53.714.6)kg and body mass index (BMI) (19.34.6)kg/m~2were in low normal range. Total lymphocyte counts (2.000.71)10~9/L and serum transferrin contents (1.800.44)g/L were decreased and the creatinine-height index (42.4321.82)% was obviously lower than normal range of adult. ConclusionsThese patients have energy deficiency. The changes of the mentioned parameters could be the reflection of the nutritional status of these patients and also closely related to the changes of their body composition. It is necessary to evaluate nutritional state of the elderly patients. However, the characteristics of the body composition of the elderly patients should not be ignored and a global assessment is needed.

Objective: To prepare surface with collagen, so as to increase the histocompatibility of deantigenic bovine cancellous bone. Methods: Bovine cancellous bone was degreased and macerated by H 2O 2 and decalcified with 0.3 mol/L HCl to form scaffold, surface of which was treaed with collagen, then cultured rabbit osteoblasts were seeded into the scaffold and cultured in vitro . 4, 10, and 21 days later, the cells on the composite materials were observed under sanning election microscope. Results: On day 4, the cells grew in the surface of the scaffold; on day 21, the cells grow into the pores and on all of the surace of the scaffold.Conclusion: Deantigenic bovine cancellous bone with surfaces treated by collagen is histocompatable with rabbit osteoblasts.

BACKGROUND: Scaffolds are an important part in bone tissue engineering. However, no perfect scaffolds have been developed for bone tissue engineering yet.OBJECTIVE: To evaluate the repair of rabbit radial defects by poly (L-lactic acid)/tricalcium phosphate(PLLA/TCP) scaffolds prepared by rapid prototyping(RP) technology so as to find a new carrier for growth factors.DESIGN: A completely randomized controlled study was conducted. SETTING: Orthopaedic institute of a military medical university.MATERIALS: The study was conducted in the General Orthopedic Institute,Fourth Military Medical University of Chinese PLA, from May 2001 to February 2002. Twenty clean New Zealand rabbits with body mass of(2.5 ±0. 5) kg for this study were obtained from the Experiment Animal Center of Fourth Military Medical University of Chinese PLA. The animals were divided into experiment group and control group with 10 rabbits in each group.INTERVETIONS: PLLA/TCP scaffolds prepared by RP technology and loaded with or without bovine bone morphogenetic protein (BMP) were used to repair the rabbit radial defects of 15 mm.MAIN OUTCOME MEASURES: Main outcomes: ① microscopic observation results of transplanted materials of the two groups; ② degradation rate of scaffolds. Secondary outcomes: ① gross observation; ② radiographic results; ③ bone density.RESULTS: At week 12, bone defect healing in experiment group was good. X-ray examination showed continuous bone callus and partial molding of different degrees. Degradation rate of scaffolds was 39.6%, and bone density in the defected part reached 70% of the normal level. All the indexes of experiment group were superior to those of control group, and no healing was found in the defected area in control group.CONCLUSION: PLLA/TCP scaffolds prepared by RP technology and loaded with bovine BMP can repair radial defects of 15mm in rabbits.

The performance appraisal (PA) system establishment in scientific research institutes on traditional Chi-nese medicine (TCM) plays an important role in the management of TCM research work, which can set up both well-defined guidance and favorable appraisal regimen for scientific researchers, so that leads to the accomplishment of the scientific objectives. However, current PA system establishment has fallen seriously behind the real demand in most TCM research institutes. As a result, there is a serious lack of a mature, efficient, standardized, propagable PA system in TCM research field. In this paper, we tried to discuss the current situation and key issues in building modern PA system in TCM research institutes. The PA system development in scientific research institutes on TCM was pointed out. The PA system should be based on existed referenced similar platforms, with full consideration on professional features and Chinese culture. The PA system establishment should be with most science, systematicness, objectivity, and guidance. The PA system should also be established to evaluate the scientific researchers equitably, guide the scientific trend, provide proper institute, and promote scientific research.

Myelodysplastic syndromes (MDS) are a heterogenous group of hematologic malignancies characterized by clonal expansion of BM myeloid cells with impaired differentiation. Of particular interest mutations is the recent recognition that genes involved in the regulation of histone function (EZH2, ASXL1,and UTX) and DNA methylation (DNMT3A,IDH 1/IDH2,TET2) are recurrently mutated in MDS,providing an important link between genetic and epigenetic alterations in this disease. Ongoing analysis of the seminal AZA-001study has taught many important lessons in the use of DNA methyltransferase (DNMT) inhibitors.Improved survival in patients with high-risk MDS treated with azacitidine extends to patients with any International Working Group-defined hematologic response.New information on the impact of DNMT inhibitors on the immune system and on stem cells will likely lead to novel uses of these drugs in MDS and other hematologic and nonhematologic malignancies. The immunomodulating drug thalidomide and its derivative lenalidomide have been used in the treatment of MDS,principally in lower-risk MDS.

Bone Diseases ; complications ; Humans ; Intestinal Polyposis ; complications ; congenital ; Metaplasia ; complications ; Neoplastic Syndromes, Hereditary ; complications

Objective To study the mechanism of mesenchymal stem cells immunosupression lym- phocyte proliferation via B7-H1/PD-1 pathway upregnlated by IFN-γ. Methods Bone marrow derived mes-enchymal stem cells (MSC) were isolated and purified by repeat adherent passage and detected them multi-potential differentiation in conditioned culture medium. Then MSC were cocuhured with lymphocyte prolifera-tion and assayed the level using γ H-thymidine incorporation. Meanwhile, ELISA measured IFN-γ, TGF-β, TNF-α and IL-10 in the cocuhured supernaatant and analyzed variation of B7-H1 molecular profile in MSC by flow cytometry. At last siRNA technology was deploied to interfere B7-H1 expression and analyzed MSC im-munosuppression on lymphocyte proliferation. Results In vitro the isolated MSC become homogeneous spi-die-shaped adherent cells after five passages, and in conditioned culture medium they could differentiate into adipocytes, osteocytes and chondrocytes. In the eocuhure of MSC with mixed lymphocyte, lymphocyte prolif- eration stimulated by Con A or by anti-CD3/CD28 antibody. The cpm value of the proliferation detected by 3H thymidine incorporation showed MSC suppressed the proliferation significantly (P = 0. 0167, 0. 0081,<0.0001 ) and the suppressive potential in a dose-dependent fashion. In the coeuhured supernatant cyto-kine IFN-T and TNF-α were detected in high concentration, but TGF-β, IL-10 were undetected. Simultane- ously MSC in the coeuhure upregulated B7-H1 expression from basic expression 7% to higher than 70% ( P < 0.05 ). After interfere B7-H1 expression in MSC by specific siRNA, we detected lymphocyte proliferation and got higher cpm by 3H thymidine incorporation ( P < 0. 05 ). Conclusion MSC upregulated B7-H1 mo-lecular expression upon the stimuli of IFN-γ, and through the B7-H1/PD-1 pathway mediated immunosu-pression on lymphocyte proliferation.

BACKGROUND: Whether the injured peripheral nerve in a late stage has repairing value still remains a problem. If irreversible changes happen in substance P and calcitonin gene-related peptide, the feeling function will lose even after repairing.OBJECTIVE: To quantitatively study the changes of substance P(SP) and calcitonin gene-related peptide(CGRP) in the spinal dorsal horn 24 weeks after peripheral nerve injury.DESIGN: A self-controlled quantitative experiment.SETTING: Institute of Orthopaedics of the Fourth Military Medical University of Chinese PLA.MATERIALS: This experiment was performed in the Institute of Orthopaedics of the Fourth Military Medical University of Chinese PLA from October 2002 to May 2003. Totally 55 SD rats were divided into 11 groups according to time points(1, 2, 3, 4, 6, 8, 10, 12, 16, 20 and 24 weeks after sciatic nerve transection).INTERVENTIONS: Sciatic nerve injury model was set up by transecting one side of sciatic nerve and ligating the proximal stump of sciatic nerve; the other side was set as the control side. Computer-assisted image analysis was used to measure the immunologic reaction areas of substance P and CGRP.MAIN OUTCOME MEASURES: Changes of the distribution of the positive fibres of SP and CGRP in rat spinal dorsal horn in each group.RESULTS: Fifty-five rats entered the result analysis. The distributions of SP immunoreactivity in the spinal dorsal horn following sciatic nerve injury showed a significant reduction during 2-6 weeks, followed by a slow rate of increase,and reached almost complete restoration at 16 weeks after deafferentation. No obvious advanced changes happened at 20 and 24 weeks. The ratios for ipsilateral and cotralateral sides of positive fibre and distribution area injury in spinal dorsal horn CGRP were 1.14 at week 1, 1.13 at week 6, and 0. 29 at week 24. The ratios were similar at each time point( P ＞ 0. 05).CONCLUSION: At the late stage of peripheral nerve injury, neurons in the spinal dorsal horn and dorsal root ganglion still remain their functions to synthesize and secrete SP and CGRP. Spinal dorsal horn remains at a balanced status and still has the neurologic basis to recover the sensory function.