Objective To investigate the effect of iodine-125 on inhibiting breast cancer growth and to explore its possible mechanism. Methods The animal model of the MCF-7 tumor was established firstly through injection of the cells into nude mice. The animals were divided into two groups before the implantation of the iodine-125 granule into the tumor mass: control group (n=40, to implant no-load seeds, non-iodine-125 radioelement) and experimental group 〔n=40, to implant iodine-125 seeds (1.48×107 Bq) when the length of tumor was 8-10 mm〕. The width and length of tumor, in order to calculate the volume, were measured every three days to observe tumor growth curve and to calculate the rate of the tumor inhibition. When the length of tumor was 15-20 mm in the control group, 30 nude mice were killed in every group to detect the weight of tumor and histopathological changes. Other ten nude mice of each group were remained to be observed the national life span and survival rate for 90 days. Results Within 90 days, the average survival time in control group and experimental group were significantly different (56.2 d vs. 74.8 d, P＜0.05). In control group the growth curve was continuously elevated, while experimental group showed a low flat curve. With iodine-125 treatment, the tumor growth decreased in experimental group with tumor inhibition rate 55.21%. The average tumor weight in control group and experimental group was (3.26±0.39) g and (1.46±0.17) g (t′=22.8962, P＜0.05). As compared with control group, under light microscope, the number of cancer cells was less, nuclear debris increased, and cancer structure was not obvious in experimental group. Conclusion This study suggests that iodine-125 seed may inhibit the growth of breast cancer, which may be involved in direct radiation breakdown of tumor cells or induction of apoptosis and inhabitation of tumor angiogenesis.
ObjectiveTo construct large block of engineered liver tissue by co-culture of fibroblasts and hepatocytes on collagen hydrogels in vitro and do in vivo implantation research. MethodsSilastic mould was prepared using three-dimensional printing technology. The collagen hydrogel scaffold was prepared by collagen hydrogel gel in the silicone mould and was removed. Sprague Dawley rat lung fibroblasts were co-cultured with primary hepatocytes at a ratio of 0.4:1 on the collagen hydrogel scaffold to construct large block of engineered liver tissue in vitro (group B), and primary hepatocytes cultured on the collagen hydrogel scaffold served as control group (group A). The cell morphology was observed, and the liver function was tested at 1, 3, 7, 14, and 21 days after culture. The rat model (n=24) of hepatic cirrhosis was made by subcutaneous injection of carbon tetrachloride. And in vivo implantation study was carried in cirrhosis rat model. The phenotypic characteristics and functional expression of hepatocytes were evaluated at 3, 7, 14, 21, and 28 days after implantation. ResultsIn vitro results indicated that hepatocytes in group B exhibited compact polyhedral cells with round nuclei and high expression of liver function. Moreover, cells aggregated to the most at 7 days. Album production and urea synthesis incresed significantly when compared with group A (P<0.05). In vivo results showed hepatocytes in group B survived for 28 days, and albumin production and urea synthesis were significantly increased. In addition, hepatocytes showed an aggregated distribution and cord-like structures, which was similar to normal liver tissue. ConclusionThe large block of engineered liver tissue constructed by co-cultured cells can form tissue similar to normal liver tissue in vivo, and survive for a long time, laying foundations for building more complete engineered liver tissue in the future.
Objective To investigate the feasibility and characteristic of tissue engineered testicular prosthesis with highdensity polyethylene(HDPE，trade name: Medpor) and polyglycolic acid(PGA). Methods The chondrocytes were isolated from the swine articular.The PGA scaffold was incorporated with medpor which semidiameters were 6mmand 4mm respectively.Then, the chondrocytes (5×10 7/ml) were seeded onto Medpor-PGA scaffold and cultured for 2 weeks. The ten BALB／C mice were divided into two groups randomly(n=5). In the experimental group, the cell-scaffold construct was implanted into subcutaneous pockets on the back of nude mice. In the control group, the Medpor-PGA scaffold was implanted. The mice of two groups were sacrificed to harvest the newly formed cartilage prosthesis after 8 weeks. Macroscopy, histology and immunohistochemistry observations were made. Results The gross observation showed that on changes were in shape and at size, the color and elasticity were similar to that of normal cartilage and that the cartilage integrated with Medpor in the experimental group; no cartilage formed and fiberlike tissue was found in the control group. HE staining showed that many mature cartilage lacuna formed without blood vessel and some PGA did not degradated completely. Toluidine blue staining showed extracellular matrix had metachromia. Safranin O-fast green staining showed that many proteoglycan deposited and collagen type Ⅱ expression was bly positive. In the control group, Medpor was encapsulated by fiber tissue with rich blood vessel. Conclusion The newly formed complex of Medpor-PGA and cells was very similar to testicle in gross view and to normal cartilage in histology. This pilot technique of creating testicular prosthesis by incorporating tissue-engineered cartilage with Medpor demonstrated success.
In order to investigate the possibility of repairing injuried tendon with living artificial tendon, after combining culture, subcultured autogenous tendon cells with carbon fibers were implanted into the calcaneous tendon of rabbits. In different stages, the synthesis of type I collagen and their relevant morphological changes were observed. The results showed as follows: after implantation, tendon cells continued proliferating. Four weeks after implantation, tendon cells were detached from the carbon fibers and proliferated and produced collagen among the carbon fibers. The collagen fibrils were linked with each other to formed a dense structure. In the linkage site, the collagen fibrils originated from the implants joined to that from the ruptured end of the tendon, which meaned that the implant was healed with the recipient tendon. Observed under scanning electronic microscope, the tendon cells were lined among the carbon fibers evenly and in order, the collagen fibrils joined each other and formed an network, the fibrils were lined parallel to the carbon fibers. Under transparent electron microscope, the nucleolus were clear and organelle were abundant.
Objective To explore the effective autologous bone marrow stem cell dosage for treatment of severe lower limb ischemia. Methods From December 2003 to December 2004, 22 cases of bilateral lower limb ischemia were treated with autologous bone morrow cell transplantation. All the patients were randomly divided into two groups according to ischemia degree. In group A(severe ischemia side), the amount of transplanted autologous bone marrow cells was more than 1×108, and ingroup B(mild ischemia side), the amount was less than 1×105. A series of subjective indexes, such as improvement of pain, cold sensation and numbness, and objective indexes, such as increase of ankle/brachial index (ABI) and transcutaneous oxygen pressure (TcPO2), angiography, amputation rate, and improvement of foot wound healing were used to evaluate the effect of autologous bone marrow stem cells implantation. Results The rates of pain relief were 90.0% in group A and 16.7% in group B (Plt;0.01); the rates of cold sensation relief were 90.5% in group A and 5.3% in group B（Plt;0.01）;the improvement of numbness was 62.5% in group A and 9.1% in group B（Plt;0.01）. Increase of ABI was 31.8% and 0 in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Increase of TcPO2was 94.4% and 11.1% in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Twelve cases of angiography showed rich new collateral vessels in 100% of the limbs in group A while no remarkable new collateral vessel in group B. The amputation rates were 4.5% in group A and 27.3% in group B（Plt;0.05） at 4 weeks after implantation. The rate of improvement of foot wound healing was 75% in group A and there was no changein wound healing in group B after 4 weeks of implantation. Conclusion The effectiveness of autologous bone marrow stem cell implantation depends on the number of implanted stem cells. Effectiveness is expected in most patients if the implanted stem cell is more than 1×108, whereas there would be little effect if the cell number is less than 1×105.
The aim of this experiment was to study the osteogenesis in vivo of allogenic osteoblast combined culture with calcium phosphate composites. The osteoblasts were obtained by enzymatic digestion of periosteum from fibula subcultured to 13 generations, the cells were combined culture with hydroxyapatite and biphasic calcium phosphate. Subseguently, the composite was implanted into rabbits subcutaneously or intramuscularly. The blank material was implanted in the contralateral side as control. Four weeks later, all animals were sacrificed. All the implants were examined by gross observation, histological examination and EDXA. The results showed: 1. obvious ingrowth of connective tissue with very little inflammatory reaction; 2. new bone formation in the composites with deposit of Ca and P on the surface of osteoblast, but none in the blank materials; 3. no significant difference of new bone formation between the different sites of implantation or different materials, but those implanted intramuscularly had lamellae form of new bone while those implanted subcutaneously had only mineralization of extracellular matrix. The conclusion were: 1. the composites are biocompatible with prior osteogenesis property; 2. periosteal-derived allogenic osteoblasts obatined by enzymatic digestion could survive following implantation with bioactivity; 3. rich blood supply might be advantageous to new bone formation and its maturation.
From the results of this experiment, it showed that the implanted tendon was gradually extruded from the tibia hole and attached to the periosteum. The dominant breeding of tissue cells, cytodynamics, the perimeter ratio of tendon/bone and the effect of revascularization were discussed in detail.
In order to observe the role of genetically modified Schwann cell (SC) with pSVP0Mcat in the regeneration of injured spinal cord, the cells were implanted into the spinal cord. Ninety SD rats were used to establish a model of hemi-transection of spinal cord at the level of T8, and were divided into three groups, randomly, that is, pSVP0Mcat modified SC implantation (Group A), SC implantation (Group B) and without cell implantation as control (Group C). After three months the presence of axonal regeneration of the injured spinal cord was examined by means of horseradish peroxidase (HRP) retrograde labelling technique and stereography. The results indicated that HRP labelled cells in Group A and B could be found in the superior region of injured spinal cord and the brain stem such as the red nuclei and oculomotor nuclei. The density of ventral hom neurons of the spinal cord and the number of myelinated axons in 100 microns of the white matter was A gt; B gt; C group. In brief, the pSVP0Mcat modified SC intraspinal implantation could promote regeneration of the injured spinal cord.
Objective To evaluate the effectiveness and safety of implanted sustained-release fluorouracil in gastric cancer surgery. Methods Literature search was conducted in the following databases: PubMed, EMbase, The Cochrane Library (Issue 6, 2012), CNKI, VIP and WanFang Data from inception to June, 2012. Randomized controlled trials (RCTs) or quasi-randomized controlled trials on implanted sustained-release fluorouracil for gastric cancer were included. Two reviewers independently identified the literature according to the inclusion and exclusion criteria, and then extracted the data and assessed the quality of the included studies. Then, meta-analysis was conducted using RevMan 5.1 software. Results A total of 7 studies involving 742 patients were included. The results of meta-analysis showed no significant difference in the rate of postoperative complications between the two groups (OR=0.93, 95%CI 0.54 to 1.59, P=0.79), while a significant reduction was found in the recurrence rate in the sustained-release fluorouracil group during 1 to 3 year follow-up (1 year after surgery: OR=0.32, 95%CI 0.22 to 0.46, P=0.02; 2 years after surgery: OR=0.19, 95%CI 0.08 to 0.42, Plt;0.001; 3 years after surgery: OR=0.40, 95%CI 0.24 to 0.67, P=0.004). As for the survival rate, no significant difference was found between the two groups 1 year after surgery (OR=1.98, 95%CI 0.92 to 4.25, P=0.08), while it was significantly higher in the sustained-release fluorouracil group than in the control group 2 to 3 years after surgery (2 years after surgery: OR=2.63, 95%CI 1.17 to 5.91, P=0.02; 3 years after surgery: OR=2.42, 95%CI 1.53 to 3.83, P=0.002). Adverse reaction rates in the sustained-release fluorouracil group were lower than those in the control group, but without significantly differences between the two groups (OR=1.22, 95%CI 0.49 to 3.07, P=0.67). Conclusion Compared with the control group, implanted sustained-release fluorouracil for gastric cancer can significantly reduce the recurrence rate 1 to 2 years after surgery and improve the overall survival rate 2 to 3 years after surgery without increasing the incidences of the postoperative complications and adverse reaction. However, due to the limitation of quantity and quality of the included studies, this conclusion should be further confirmed by more high quality, larger sample and multi-center RCTs.
Objective To introduce a new type of bileaflet mechanical prosthetic heart valve （GK bileaflet valve）and evaluate clinically the early hemodynamic effect and short term follow-up after its replacement. Methods Sixty-one patients with heart valve diseases were operated upon. The mitral valve replacement was performed in 34 patients, aortic valve replacement in 16 patients and double valve replacement in 11 patients. A total of 72 GK bileaflet mechanical valves were implanted, 45 in mitral position, and 27 in aortic position. Blood consistency and hemodynamics were monitored. Follow-up was carried out routinely to check whether there were some valve-related complications. Results There was no early mortality （〈30 d）. Only one patient died of trauma 2 months after the operation. Follow-up was 100% and extended 1 to 2. 5 years. Without valve-related complications all patients had lived for more than 1 to 2.5 years. In 98% （60/61） of survivors heart functional performance had improved to New York Heart Association class Ⅰ or Ⅱ . Conclusion Early clinical results and short term follow up demonstrate that GK bileaflet prosthetic heart valve exhibits excellent hemodynamic properties, satisfied blood consistency and a low incidence of valve-related complications. Midterm and long-term results should be observed further.