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Objective To clarify the temperature curve of the irradiation target area,its adjacent tissue and the whole body during extracorpereal microwave irradiation, then to compare and optimize different irradiation models. Methods Different parts of the chest of adult New Zealand white rabbit were irradiated using different extracorporeal microwave irradiation models. The temperature of the irradiated skin, the subcutaneous and deep parts, the adjacent tissues and the anus was measured. The experiment was bi-factor and multi-level designed according to the repeatedly measured data and the rabbits was divided into group a,b,c and d. Results The increase rate of the surface temperature in the dorsal lung was similar between group d and group b1(F=10.04,P<0.01). However,the increase rate of the surface temperature in the ventral lung of group d was lower, and the mean temperature of this site measured 10 minutes later was also lower than group b1(F=10.04,P<0.01). The increase rate of the rectal temperature of group d was higher,and the mean rectal temperature tested 10 minutes later was also higher than group b1(F=7.04,P<0.01). Conclusions Multi-array irradiation could achieve satisfactory irradiation depth and appropriate therapeutic temperature. Well controlled extracorporeal microwave irradiation under is an ideal thermotherapy method.
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BACKGROUND: Mesenchymal stem cells (MSCs) are capable of differentiating into a variety of lineages, including bone, cartilage, or fat, depending on the inducing stimuli, specific growth and differentiation factors.Recombinant human bone morphogenetic protein 2 (rhBMP-2) produced by gene engineering has an obvious osteoinductive activity and can induce undifferentiated mesenchymal cells into cartilage and bone irreversibly, resulting in new bone formation. Basic fibroblast growth factor (bFGF) modulates chondrogenic and osteogenic differentiation of MSCs.OBJECTIVE: To investigate the effect of bFGF and rhBMP-2 on the differentiation and proliferation of cultured rabbit mesenchymal stem cell in order to find out an optimal way of osteogenesis instead of conventional osteogenic supplements (OS).DESIGN: A randomized and controlled trial.SETTING: General Institute of Orthopaedic Oncology, Tangdu Hospital,Fourth Military Medical University of Chinese PLA.MATERIALS: The subjects were rabbit mesenchymal stem cells cultured by the author.METHODS: This experiment was conducted at the Center of Orthopaedic Surgery, General Institute of Orthopaedic Oncology, Tangdu Hospital,Fourth Military Medical University of Chinese PLA from June 2004 to December 2004. ①Rabbit MSCs cultured in vitro were treated with different growth factor (100 μg/L rhBMP-2, 100 μg/L bFGF, 10 μg/L rhBMP-2and 100 μg/L bFGF and OS; ②The proliferation and differentiation of MSCs were observed through activity of MTT, expression of alkaline phosphatase(ALP), and von Kossa staining.MAIN OUTCOME MEASURES: the rate of proliferation and the activity of ALP.RESULTS: ①rhBMP-2 could promote the proliferation and differentiation of MSCs, especially the cell differentiation; ②bFGF could stimulate the proliferation , the cellular proliferation rate increased 100% as compared with control group, and has no effect on differentiation of MSCs , but it could enhance effect on the cell proliferation of rhBMP-2.CONCLUSION: bFGF and rhBMP-2 are effective induction factors for MSCs. Both of them can stimulate the proliferation and differentiation of MSCs in vitro. bFGF and rhBMP-2 exerted a synergetic action in speeding up the pace of osteoinduction and osteogenesis and can be used to differentiate seed cells for tissue engineering bone.
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BACKGROUND: Composite with different ratios has various elastic noduli, and this can cause stress protection in implanted body so as to influence on biological integration between composite and host bone and plerosis of bone defection.OBJECTIVE: To measure elastic modulus of tissue engineering bone made of composite between true bone ceramic (TBC) granule and bone cement (BC) and provide experimental data for repairing bone defection at various sites.DESIGN: Controlled study.SETTING: Military Institute of Bone Tumor, Tangdu Hospital of the Fourth Military Medical University of Chinese PLA.MATERIALS: The experiment was carried out in the Military Institute of Bone Tumor, Tangdu Hospital of the Fourth Military Medical niversity of Chinese PLA from August 2002 to March 2003. Ten Kunming mice,weighing 10-15 g, of both genders, were selected in this study. Fresh longtubular cortical bone of 1-year calf, 6 samples of spongy bone at inferior extremity and 6 samples at iddle femur of fresh corpse were also selected in this study.METHODS: Bovine bone morphogenetic protein (bBMP) was xtracted to measure osteogenic-induced activity and make TBC granule. bBMP was mixed with TBC as the ratio of 1:25, and then with BC as the ratios of 0:10, 4:6, 5:5,6:4 and 7.5:2.5. In addition, elastic modulus of tissue engineering bone made of TBC-BC composite was measured and compared with elastic modulus of femur and spongy bone of normal adult males.MAIN OUTCOME MEASURES: Measurement and comparison of elastic modulus.RESULTS: Elastic modulus of composite containing 60% TBC (Ratio between TBC and BC was 6:4) was no significantly different from that of spongy bone at inferior extremity of femur of normal adult males (P ＞ 0.05),but other comparisons of every two subjects were significant difference [femur of the adults: (6.216 7±0.222 9) Mpa; spongy bone: (1.351 7±0.306 9) Mpa;TBC/BC (0:10): (5.710 0±0.166 3) Mpa; TBC/BC (4:6): (3.510 1±0.205 0) Mpa;TBC/BC (5:5): (2.004 1±0.150 0) Mpa; TBC/BC (6:4): (1.501 8±0.005 7) Mpa;TBC/BC (7.5:2.5): (0.900 4±0.025 1) Mpa, P ＜ 0.01].CONCLUSION: Elastic modulus of composite containing 60% tissue engineering bone made of TBC-BC composite is similar to that of spongy bone at inferior extremity of femur of adult males. The composite can be used to repair bone defection near by articular facet so as to prevent from articular degeneration.
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In a least square method, an exponential function fits the energy density distribution of fundamental and harmonic frequency component in a long-term ECG energy spectrum. A distributing index of the function was used to quantify divergence and convergence degree of energy density. The function fits locally the ECG energy spectrum data that were collected from the young (21-34 yr) group and elderly (68-81 yr) group rigorously energy density ratio of the harmonic to fundamental frequency component and recognizability number of harmonic frequency component were significantly less in the young group than in the elderly group (P < 0.01), the center frequency f0 and energy density at center frequency f0 did not differ between the two age groups. These data indicate that the characteristic parameter values presented in this study can serve as a new measurement of heart rate fluctuations.
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Humans , Age Factors , Electrocardiography , Methods , Heart Rate , Physiology , Principal Component Analysis , Signal Processing, Computer-AssistedABSTRACT
Objectives:To study the effects of gene therapy with tissue type plasminogen activator(t PA)cDNA on the formation of thrombo embolism in vascular anastomotic sites. Methods:①The cDNA encoding t PA was amplified by RT PCR using the isolated total RNA as the template from the Bowes melanoma cells.②Recombinant plasmid pAdCMV t PA was cotransfected into 293 cells with pJMa 17 ,and the infectious but replication deficient AdCMV t PA was generated.③The rats were randomly divided into the control and treatment groups.11 0 nylone medical suture was applied to perform rat carotid artery end to end anastomoses.In the treatment group,AdCMV t PA solution was injected into the vascular anastomotic site while AdCMV (no containing t PA DNA) solution was injected into the control group. By means of RT PCR and chromogenic plasmin substrates,the following results were obtained. Results:①The t PA cDNA was successfully cloned and its eukaryotic expressing vector was constructed.②When the isolated RNA was performed with RT PCR,1.69 kb band appeared in the treatment group while the band could not be found in the control group.The t PA activity could be detected postoperatively on the 1st,2 nd,3 rd,4 th,5 th,6 th,7 th,10 th and 13 th day of the treatment,but could not be detected in the control group. Conclusions:The t PA gene can produce t PA having biological activity at anastomotic sites, possibly prevent the formation of thrombus embolism effectively and develop the anastomotic patency.
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The myocardial ischemia model was established by ligating the left anterior descending artery of mice for 10 min. The ECG signal were collected from the mouse with acute myocardial ischemia and from the healthy mouse as controls. The frequency of data acquisition was 500 Hz. The measurement time around 20 seconds was chosen. The wavelet transform technique, a time-frequency method with logarithmic frequency resolution, was used to analyze the ECG signal. Mexican Hat wavelet was used and the scale factor was chosen from an interval [0.00125, 2.5] for evaluating its wavelet coefficient at corresponding scale respectively, thus the central frequency of the band-pass filter was within a range of 200-0. 1Hz. Then we evaluated the signal energy in the bandwidth delta fat frequency f. A variational rule was obtained, i.e. rat's ECG signal energy varies with frequency before and after myocardial ischemia. The results showed that in the mice suffering from acute myocardial ischemia the average signal energy increases in 0.1-1. 0Hz and 1-10 Hz segments and decreases in 10-200 Hz segment.
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Animals , Female , Male , Rats , Acute Disease , Algorithms , Electrocardiography , Methods , Fourier Analysis , Myocardial Ischemia , Diagnosis , Signal Processing, Computer-Assisted , Time FactorsABSTRACT
Objective To investigated the biological procedure of allograft decalcified bone matrix(DBM)and bone cement(BC)combined with bovine bone morphogenetic protein (bBMP)used for the repair of femoral defect caused by microwave－ induced hyperthermia in dogsby 99mTc－ MDP bone scintigraphy.Method The canine femoral defect(length 25mm,width 10mm)was caused by microwave－ induced hyperthermia(50℃ ,20minutes)and the composite material was implanted .Then the canine femurs were examined by 99mTc－ MDP bone scintigraphy respectively at different postoperative time and the results were compared with that of X－ ray photography and histological observation.Bone cement was implanted in the other femur as a contrast.Results It could be observed at the first and the second month that the radioisotope was gathered in the place where the composite material was implanted and the amount of radioisotope gathered in was the most abundant at the third month and it was lasted to the fourth month. That of the sixth month was decreased to that of the second month.The radiation count of the first, the second, the third the fourth and the sixth month were 93.9± 12.7, 110.7± 16.4,222.1± 24.0,201.3± 26.9 and 111.6± 20.7 respectively,and the count of the third month and the fourth month were more than that of the first, the second and the sixth month(P<0.01).Conclusion The composite material could be remodeled easily and the new bone could be formed by the induction of bBMP. So it could be merged with the normal bone.While the 99mTc－ MDP bone scintigraphy is the object and reliable index to determine the biological procedure of the composite material in dogs.
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Objective To observe the feasibility of using bone marrow-derived mesenchymal stem cells (MSCs) as seed cells for tissue-engineering in Otolaryngology. Method MSCs were isolated from bone marrow of human rib and purified by centrifuge and cultured in vitro. The proliferation and growth characteristics of MSCs were observed in primary and passage culture. Result Human bone marrow-derived MSCs showed active proliferation capacity in vitro in primary and passage cultures. Conclusion Human bone marrow-derived MSCs have relatively young biologic age and they can be used as the seed cells for tissue engineering.
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Objective:To explore caspase-6's effect on the apoptosis of osteosarcoma cell line SOSP 607. Methods: The expression level of caspase-6 in the osteosarcoma cell line SOSP-9067 was examined by RT-PCR method. The adeno-virus adv5 vector with caspase-6 gene was constructed and transferred into the osteosarcoma cell line SOSP-9607 by lipo-fection. The cell survival rate after transfection was assayed by MTT method. The cell morphological changes were observed by microscope and electron microscope, the apoptosis of transferred cells were examined by gel electrophoresis. Results:No expression of caspase-6 was examined in the osteosarcoma cell line SOSP-9607. A high expression of caspase-6 was identified by RT-PCR after the transfection. The cell growth curve declined after transferring caspase-6. Electrophoresis of DNA displayed the apoptosis ladder. Conclusion: Transferring caspase-6 into the osteosarcoma line SOSP-9607 may inhibit the growth of the osteosarcoma cell line SOSP-9607 and this effect might be achieved by inducing apoptosis.