A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
OBJECTIVE: To evaluate the clinical effect of drilling procedure following the hydroxyapatite orbital implantation. METHODS: From February 1996 to April 2000, 146 consecutive patients who received hydroxyapatite orbital implant were drilled and inserted a motility peg 6 to 16 months after hydroxyapatite implantation. Among them, there were 97 males and 49 females, aged from 18 to 60 years old, of the 146 motility pegs, 36 were sleeved pegs and 110 were nonsleeved. Goldman visual field analyzer was applied to measure the degree of artificial eye’s movement before and after drilling. RESULTS: Followed up for 1 to 40 months, no secondary infection occurred. The mobility of the prosthesis increased from (18.7 +/- 3.8) degrees preoperatively to (42.3 +/- 3.7) degrees postoperatively. CONCLUSION: The delayed drilling procedure and motility peg insertion improve the range of movement and the sensitivity of the artificial eye with a low rate of complications.
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.
Implantable left ventricular assist device (LVAD) has become an essential treatment for end-stage heart failure, and its effect has been continuously improved. In the world, magnetic levitation LVAD has become mainstream and is increasingly used as a destination treatment. China has also entered the era of ventricular assist device. The continuous improvement of the ventricular assist device will further improve the treatment effect. This article reviews the current situation and development trend of LVAD treatment in China and abroad.
In order to study the Titanium-bone interaction and integration mechanism, the titanium implant was implanted in the tibia of 9 Newzealand rabbits, and the Ti-bone interface performed for 1, 3, and 6 months were examined and analyzed by fluorescence microscope and advanced TOF-SIMS techniques. The results showed that Ti-bone tissue was integrated closely in a very reactive manner. Both physical and chemical integration occurred in the Ti-bone interface. The Ti-bone could diffuse into the bone tissue though the diffusion was very limited. It was up to 100 microns in depth during the early period. The diffusion density was high, and later in a smooth distribution. Furthermore, while Ti+ diffused into the bone tissue, other elements such as Ca+, OH-, O-, etc, could also diffuse into titanium in exchange. The growth pattern around the bone tissue was in two fashions, one was implantefugal and the other was implantopetal. In this study, based on the ionic distribution, osmosis and impurity elements distribution, the Ti-bone integration mechanism was discussed at molecular and atomic level.
ObjectiveTo explore the antitumor effect of tumor vaccine fused from dendritic cells (DC) and Walker-256 cancer cells on implanted liver cancer in rats and the related mechanism of inhibition for tumor angiogenesis. MethodsWalker-256 cancer cells and mature DC were fused by 50% polyethylene glycol method for preparation of DC-Walker-256 fusion vaccines. Implanted liver cancer models were established through operations on healthy male SD rats at the age of 6－8 weeks. All the rats were divided into four groups, and rats in each group were injected subcutanely with fusion vaccine (group), mixed cultured cells (group), simple DC (group), and PBS (blank control group), respectively. On 28 d after making model, the rats were put to death, the tumor was observed and pathological essays were prepared. All rats’ spleens were collected and prepared into lymphocyte to detect antigenic specificity cytotoxic T lymphocyte (CTL) by enzymelinked immunosorbent spot (ELISPOT) method. The expressions of VEGF, ANG-1, ANG-2, and MVD were detected by immunohistochemistry. ResultsThe numbers of rats survived in the fusion vaccine group, mixed culture cells group, simple DC group, and blank control group was 8, 5, 6, and 3, respectively. The rats in the other three groups except for fusion vaccine group were manifested as inaction, anorexia, and gloomy fur in some degree as well as ascites. The tumorigenesis was found in all survival rats except for two in the fusion vaccine group. The weight of liver tumors of rats in the fusion vaccine group 〔(32.4±9.2) g〕 was significantly lighter than that in the mixed culture cells group 〔(67.3±5.1) g, P=0.031〕, simple DC group 〔(75.0±8.3) g, P=0.019〕, and blank control group 〔(86.6±10.5) g, P=0.008〕, respectively. The number of tumorspecific CTL of rats in the fusion vaccine group was also significantly higher than that in the other three groups (P=0.019, P=0.025, and P=0.001, respectively). The MVD of tumor tissue in the fusion vaccine group was (24.12±2.32) vessels/HP, which was significantly lower than that in the mixed culture cells group 〔(40.34±1.29) vessels/HP, P=0.025〕, simple DC group 〔(42.36±3.16) vessels/HP, P=0.035〕, and blank control group 〔(56.48±5.16) vessels/HP, P=0.006〕, respectively. The MVD of tumor tissue in the mixed cultured cells group and simple DC group was similar (P=0.165), however, which was significantly lower than that in the blank control group (P=0.040 and P=0.043). The positive rate of VEGFA protein expression was 23.2% in the fusion vaccine group, which was significantly lower than that in the mixed culture cells group (42.5%, P=0.031), simple DC group (61.3%, P=0.019), and blank control group (89.6%, P=0.003), respectively. The positive rate of VEGF-A protein expression in the mixed cultured cells and simple DC groups was similar (P=0.089), however, which was significantly lower than that in the blank control group (P=0.027 and P=0.038). The positive rate of ANG-1 protein expression in the fusion vaccine group (43.2%) was not different from that in the mixed culture cells group (46.3%, P=0.292), simple DC group (51.3%, P=0.183), or blank control group (49.6%, P=0.179), respectively, and the difference of pairwise comparison in latter three groups was not significant (P=0.242, P=0.347, and P=0.182). The positive rate of ANG2 protein expression was 19.2% in the fusion vaccine group, which was significantly lower than that in the mixed culture cells group (62.3%, P=0.007), simple DC group (67.3%, P=0.005), and blank control group (71.6%, P=0.004), respectively, however, the difference of pairwise comparison in latter three groups was not significant (P=0.634, P=0.483, and P=0.379). ConclusionFused vaccine can induce CD8+ CTL aiming at tumor cells and establish the effective antitumor immunity in vivo and also downregulate the level of VEGF and ANG-2 to suppress tumor angiogenesis and thereby achieve the purpose of curing tumor.
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 observe the expression of related proteins of retina after subretinal implantation with inactive chips.Methods A total of 27 healthy adult New Zealand white rabbits were randomly divided into three groups: operation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina;shamoperation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina which was taken out immediately;the control group (3 rabbits). Animals were sacrified for immunohistological study 7,15,30 and 60 days after surgery.The rabbits in control group group were sacrified for immunohistological study after bred for 30 days.The expressions of glial fibrillary acidic protein (GFAP) and brain derived neurotrophic facor (BDNF) were observed.Results In operation group, the outer nulear layer of retina thinned, and the cells in the inner nulear layer was disorganized 7,15,and 30 days after the surgery;glial cells proliferated 60 days after surgery; the positive expression of BDNF and GFAP was more than that in the shamoperation and control group.In shamoperation group, the positive expression of BDNF and GFAP was more than that in the control group.No obvious difference of expression of BDNF and GFAP between each time point groups was found.Conclusions The expression of neroprotective related proteins increased after subretinal implantation with inactive chips suggests that limited neuroprotective effects might be led by the implantation.
ObjectivesTo systematically review the patients’ satisfaction of implant supported mandibular dentures and conventional dentures.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang and VIP databases were searched to collect randomized controlled trials (RCTs) on patients’ satisfaction of implant supported mandibular dentures (IODs) and conventional dentures (CDs) from inception to November 31st, 2016. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of the included studies. Then, meta-analysis was conducted using RevMan 5.3 software.ResultsSeven randomized-controlled trials were identified. The results of meta-analysis showed that compared with CDs group, IODs group had a relatively higher level of patients’ satisfaction (SMD=1.11, 95%CI 0.79 to 1.43, P<0.001) and oral health quality of life (MD=–12.41, 95%CI –18.96 to –5.86,P<0.001).ConclusionsThe current evidence suggests that IODs may be a better choice for mandibular edentulous patients than CDs. Due to the limitations of the quality and quantity of the included studies, the above conclusions still require larger sample and high quality research to verify.
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.