Objective To review new progress of related research of bone tissue engineering in recent years. Methods Domestic and international l iterature concerning bone tissue engineering was reviewed and analyzed. Results In the recent years, great progression had been made in the research and development of bone tissue engineering, it had been used in more and more hospitals, and relevant national regulations and protocols had been set up. As to seed cells of bone tissue engineering, autologous and allogeneic stem cells had been widely used, while recently embryonic stem cells and induced pluri potent stem cells had attracted most attentions. In the field of scaffolds materials, significant improvementshad been made, from natural extractions to artificial polymers; from single construction to multiple compounds with surface modifications. As to the methods of construction, the static seeding approach had been widely accepted, and the appl ications of bioreactor had provided a stable and various micro-enviroment for the vitro-culture of different stem cells, which had beenregarded as an alternative way of vitro-culture and construction for bone tissue engineering. Conclusion With the tremendous help of the techniques and approaches above, we shall expect a promising future of a new generation bone tissue engineering based medical products in the years to come.
Objective To investigate the possibility of ectomesenchymal stem cell of human embryo facial process in differentiating into osteoblasts.Methods Ectomesenchymal stem cells of human embryo facial process were isolated and cultured in mineralized promoting solution containing 10 mmol/L β-glycerophosphate, 100 μg/ml ascorbic acid and 10 nmol/L dexamethasone supplemented with 15% FBS. The morphological change was observed by phase contrast microscopy. The characteristics of cells was identified by immunohistochemistry assay. Alkaline phosphatase activity was tested and the form of mineralized nodules was tested with Von Kossa staining. The expression of osteocalcin was identified by RT-PCR.Results There were significant changes in the shape of the cells after 3 days cultured in mineralized promoting solution. The cells became larger and the shape changed from fibroblast-like to multilateral. The result for anticollogen typeⅠstaining was positive. The alkaline phosphatase activity increased. Mineralized nodules were formed aftercultured 25 days by Von Kossa staining. RT-PCR assay showed induced cells expressed osteocalcin.Conclusion Ectomesenchymal stem cells of humanembryo facial process can be induced to differentiate into osteoblasts by mineralized promoting solution.
ObjectiveTo study the possibility of the C17.2 neural stem cells (NSCs) differentiating into neural cells induced by serum-free condition medium of olfactory ensheathing cells (OECs) and to detect the cell viability of the differentiated cells.
MethodsOECs were isloated and cultured from the olfactory bulbs of 3-day-old postnatal mouse to prepare serum-free condition medium of OECs. After C17.2 NSCs were cultured with H-DMEM/F12 medium containing 15% FBS and the cell fusion reached 80%, the 3rd passage cells were induced by serum-free condition medium of OECs in the experimental group, by H-DMEM/F12 in the control group, and non-induced C17.2 NSCs served as the blank control group. The growth condition of cells was observed with inverted microscope. After 5 days, the immunofluorescence staining[microtubule-associated protein 2 (MAP-2) and β-tubulin-Ⅲ] and Western blot (Nestin, β-tubulin-Ⅲ, and MAP-2) were carried out to identify the neural cells derived from NSCs. The cell viabilities were measured by MTT assay and the quantity of lactate dehydrogenase (LDH) release in the medium.
ResultsIn the experimental group, the C17.2 NSCs bodies began to contract at 24 hours after induction, and the differentiated cells increased obviously with long synapse at 3 days after induction; in the control group, the cell morphology showed no obvious change at 24 hours, cell body shrinkage, condensation of nuclear chromatin, and lysis were observed at 3 days. The immunofluorescence staining showed that β-tubulin-Ⅲ and MAP-2 of C17.2 NSCs were positive at 5 days after induction, and Western blot suggested that the expression of Nestin protein declined significantly and the expressions of β-tubulin-Ⅲ and MAP-2 protein were increased in the experimental group, showing significant differences when compared with those in the control group and blank control group (P<0.05). The LDH release and the cell viability were 130.60%±6.86% and 62.20%±3.82% in the experimental group, and were 178.20%±5.44% and 18.00%±3.83% in the control group respectively, showing significant differences between 2 groups (P<0.05). The LDH release and the cell viability of experimental group and control group were significantly lower than those of blank control group (100%) (P<0.05).
ConclusionNeurotrophic factors from OECs play an important role in inducing C17.2 NSCs differentiation into neural cells and keeping the viability of differentiated cells after induction.
Objective To study the effect of splenectomy on the anti-tumor immunity in rats with induced hepatocellular carcinoma (HCC). Methods At the second and fourth month of the induced HCC, the NK cell activity, TNF-α level and total lymphcyte in blood were measured in the group of splenectomy and the control group. Results There were no different in the total lymphcyte and TNF-α in the blood in two groups, but there were significant difference in the NK cell activity between the group of splenectomy and the control group (Ｐ＜0.05). Conclusion There are some change in the anti-tumor immunity after splenectomy in rats, in which NK cell activity is at low level continuously. TNF-α isn′t affected after the second month after splenectomy.
Objective To explore changes of 3’-glutamylcysteine synthetase( γ-GCS)and reduced glutathione(GSH)in patients with bronchial asthma．Methods Ten patients with acute asthma were enrolled and treated for six weeks according to guideline recommendations．Levels of -GCS，GSH and malondialdehyde(MDA)in total cells in induced sputum and GSH，MDA，reactive oxygen(ROS)in selum were measured and compared before and after therapy．Ten healthy volunteers were as normal contro1．Meanwhile，the pulmonary function(FEVl％pred)was measured and asthmatic symptoms were quantified using Hogg’s way．Results A．In serum and sputum of the asthma patients，GSH were lower and MDA were higher before treatment than those of the control(Plt;0．01)．And -GCS in induced sputumwere higher before treatment than those of contro1．B．After treated for six weeks．levels of GSH in serum and sputum of the asthma patients increased copmpared to baseline(all Plt;0．01)，but were still lower than that of control(Plt;0．05)．Activities of MDA in serum and sputum and -GCS in sputum were elevated compared to baseline(Plt;0．01)，but still higher than that of control(all Plt;0．05)．C．Levels of GSH in serum of all patients were correlated negatively witll asthmatic symptom scores and levels of MDA and ROS(r=－0.701，－0.901，－0.878；Plt;0.05，lt;0.01，lt;0.01)．There was a positive relationship between levels ofGSH in serum and FEV1％pred(r=0．854，Plt;0．01)．In induced sputum，activities of 3’-GCS in all patients was correlated positively with their asthmatic symptom scores and level of MDA f r=0．804，0.926；Plt;0.05，lt;0.叭)．Conclusion γ-GCS and GSH may participate the reaction of
Objective To investigate the effect of NGF on fracture heal ing, and to study the role of BMP-2 induced osteoblast. Methods Sixty cleaned male Kunming mice (aging 6-8 weeks and weighing 23-25 g) were made fracture models in the middle of femoral shaft and randomly divided into four groups (groups A, B, C and D, n=15). Fracture was treated with NGF/ normal sal ine, BMP-2, BMP-2 /NGF/normal sal ine, and normal sal ine in groups A, B, C and D, respectively. After 14, 21 and 28 days, the specimens were selected from 5 mice each group to do the biochemical and histological analysis. Beforethe mice were killed, the arteriovenous blood was taken from their eye-ball to test the ALP activity. Results After 14 days,21 days and 28 days, the gross observation showed that the size and hardness of bone tissue, and callus tissue growth increased in groups A, B and C order and were higher than those in group D; the X-ray films showed that the calcified area increased in groups A, B and C order and were higher than those in group D; the histological observation showed that the trabecular maturity increased in groups A, B and C order and were higher than those in group D. The osteoblast area, the gray degree value of the radiographs in callus tissue, the ALP contents of serum and callus tissue, calcium content of callus tissue and net weight of callus were higher in groups A, B and C than in group D. There were significant differences (P lt; 0.05) in osteoblast area and gray degree values of the radiographs at 14, 21 and 28 days; in ALP contents of serum at 14 days; in ALP contents of callus tissue at 14 days and 21 days; in calcium content of callus tissue at 21 days and 28 days among 4 groups. There were significant differences in net weight of callus between groups B, C and groups A, D at 14 days (P lt; 0.05). At 21 days and 28 days, the trabecular surface index of osteoblast, the average trabecular volume and the mean trabecular width decreased as time went on, having an increase order of groups A, B, C and was higher in groups A, B, C than in group D, showing significant differences among 4 groups (P lt; 0.05). Conclusion NGF promotes the heal ing of fractures. NGF possesses synergistic effect on ectopic bone formation induced by BMP-2.
Objective
To evaluate the effectiveness of induced membrane technique in the treatment of infectious bone defect.
Methods
Thirty-six patients (37 bone lesions) with infectious bone defects were treated with induced membrane technique between January 2011 and June 2014. There were 28 males and 8 females with an average age of 36 years (range, 20-68 years). All bone defects were post-traumatic infectious bone defect. The bone defect was located at the tibia and fibula in 24 cases (25 bone lesions), at femurs in 6 cases (6 bone lesions), at ulnas and radii in 2 cases (2 bone lesions), at calcanei in 3 cases (3 bone lesions), and at clavicle in 1 case (1 bone lesion). The average time between onset and the treatment of induced membrane technique was 6.2 months (range, 0.5-36.0 months); 15 patients were acute infections (disease duration was less than 3 months). At the first stage, after the removal of internal fixator (applicable for the patients who had internal fixation), complete debridement of infection necrotic bone tissue and surrounding soft tissue was performed and the bone defects were filled with antibiotic-impregnated cement spacers. If the bone was unstable after debridement, external fixator or plaster could be used for stabilization. Patients received sensitive antibiotics postoperatively. At the second stage (usually 6-8 weeks later), the cement spacer were removed, with preservation of the induced membrane formed by the spacer, and filled the bone defect with autologous iliac bone graft within the membrane.
Results
The hospitalization time after debridement was 17-30 days (mean, 22.2 days), and the hospitalization time after the second stage was 7-14 days (mean, 10 days). All the flaps healed uneventfully in 16 cases treated with local flap transposition or free flap grafting after debridement. One patient of femur fracture received Ilizarov treatment after recurrence of infection at 11 months after operation; 1 patient of distal femoral fracture received amputation after recurrence of infection at 1 month after operation; 1 patient of distal end of tibia and fibula fractures received ankle arthrodesis after repeated debridements due to the recurrence of infection; 1 patient of tibia and fibula fractures lost to follow-up. The other 32 patients (33 bone lesions) were followed up 1-5 years (mean, 2 years) without infection recurrence, and the infection control rate was 91.7% (33/36). All the patients had bony union, and the healing time was 4-12 months (mean, 7.5 months); no refracture occurred. One patient of femur bone defect had a lateral angulation of 15° and leg discrepancy of 1.5 cm. Superficial pin infection was observed in 7 cases and healed after intensive wound care and oral antibiotics. Adjacent joint function restriction were observed in 6 cases at last follow-up.
Conclusion
Induced membrane technique is a simple and reliable technique for the treatment of infectious bone defect. The technique is not limited to the size of the bone defect and the effectiveness is satisfactory.
The effects of all-trans retinoic acid (ATRA) on primary gastric carcinoma models made by subcutaneous implanting gastric cancer to mice were observed. Thirty-two cancer bearing nude mice were randomly divided into 4 groups: control group (group Ⅰ)， ATRA low dose feeding group (100μg/day， group Ⅱ), moderate dose feeding group (300μg/day， group Ⅲ), and high dose feeding group (1 000 μg/day, group Ⅳ). The alteration of tumor growth, morphology, cytobiology, and immuno-histochemical assay were perfermed. The results showed significant inhibition of tumor growth and inducing differentiation in the group Ⅲ and group Ⅳ as compared with group Ⅰ (Ｐ＜0.01),and inhibited expression of p53, p21 protein in implanted tumor. The authors consider that ATRA has some effects of growth inhibition and differentiation on gastric cancer cells in vivo, and these is related to the inhibition of expression p53 and p21 onco-gene of cancer cells and accelerate apoptosis of carcinoma cells.
In transcranial magnetic stimulation (TMS), the conductivity of brain tissue is obtained by using diffusion tensor imaging (DTI) data processing. However, the specific impact of different processing methods on the induced electric field in the tissue has not been thoroughly studied. In this paper, we first used magnetic resonance image (MRI) data to create a three-dimensional head model, and then estimated the conductivity of gray matter (GM) and white matter (WM) using four conductivity models, namely scalar (SC), direct mapping (DM), volume normalization (VN) and average conductivity (MC), respectively. Isotropic empirical conductivity values were used for the conductivity of other tissues such as the scalp, skull, and cerebrospinal fluid (CSF), and then the TMS simulations were performed when the coil was parallel and perpendicular to the gyrus of the target. When the coil was perpendicular to the gyrus where the target was located, it was easy to get the maximum electric field in the head model. The maximum electric field in the DM model was 45.66% higher than that in the SC model. The results showed that the conductivity component along the electric field direction of which conductivity model was smaller in TMS, the induced electric field in the corresponding domain corresponding to the conductivity model was larger. This study has guiding significance for TMS precise stimulation.
ObjectiveTo explore the characteristics of induced sputum microbiome in the patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).MethodsInduced sputum samples from 55 patients with AECOPD and 45 patients with stable COPD were analyzed by sequencing of 16S rRNA gene. Microbiota was measured by alpha diversity, beta diversity and LDA effect size analysis (LefSe).ResultsThe microbiome diversity of induced sputum in the AECOPD group was lower than that in the stable COPD group. The microbiome richness in the AECOPD group was higher than that in the stable COPD group. The microbiome structure changed in the AECOPD group compared with the stable COPD group. The proportion of some common pathogens got enriched. The levels of hypersensitive C reactive protein (hs-CRP), interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-α) and Global Initative for Chronic Obstructive Lung Disease (GOLD) grade were negatively related to the diversity of microbiome in the AECOPD group.ConclusionsThe microbiome diversity of induced sputum in AECOPD patients is decreased, and is negatively correlated with the levels of hs-CRP, IL-8, TNF-α and GOLD grade. There are differences in the microbiome structure between AECOPD and stable COPD patients. Some enrichment of common pathogens are found in the induced sputum of patients with AECOPD. These results suggest that there is a significant bacterial dysbiosis in patients with AECOPD.
