[Advances of studies on culture and product functions of Euglena gracilis].

Euglena gracilis is a unicellular eukaryote between animal and plant cells, which is widely distributed in nature. E. gracilis has both plant and animal characteristics, and can grow photoautotrophically, heterotrophically and mixotrophically. E. gracilis also features on abundant and various cellular composition. Recently, extensive researches on unique cellular components of E. gracilis have revealed its application in the field of medicine, food, and feedstuff, in terms of improving immunity, fighting inflammation, and lowering uric acid levels. The application prospects of paramylon in biomedical area were also discovered. As food ingredients, food additives, feedstuffs and cosmetic ingredients, E. gracilis has been certified domestically and overseas. A series of products have been developed overseas, especially in Japan. However, the research and development of E. gracilis are still in its infancy in China, and there is huge space for development. At present, the research and potential application of cultivation and product functions of E. gracilis have been rarely reviewed. This review systematically examines both the domestic and abroad research of cultivation and production of E. gracilis, as well as the biological activity of E. gracilis powder and paramylon. The existing problems in the application, exploitation, and possible development direction of E. gracilis in the future are prospected. This review might be useful for establishing and optimizing large-scale and efficient heterotrophic technology, as well as developing related products of E. gracilis with specific functions.

Sub-differentiation of PI-RADS 3 lesions in TZ by advanced diffusion-weighted imaging to aid the biopsy decision process.

Background: Performing biopsy for intermediate lesions with PI-RADS 3 has always been controversial. Moreover, it is difficult to differentiate prostate cancer (PCa) and benign prostatic hyperplasia (BPH) nodules in PI-RADS 3 lesions by conventional scans, especially for transition zone (TZ) lesions. The purpose of this study is sub-differentiation of transition zone (TZ) PI-RADS 3 lesions using intravoxel incoherent motion (IVIM), stretched exponential model, and diffusion kurtosis imaging (DKI) to aid the biopsy decision process. Methods: A total of 198 TZ PI-RADS 3 lesions were included. 149 lesions were BPH, while 49 lesions were PCa, including 37 non-clinical significant PCa (non-csPCa) lesions and 12 clinical significant PCa (csPCa) lesions. Binary logistic regression analysis was used to examine which parameters could predict PCa in TZ PI-RADS 3 lesions. The ROC curve was used to test diagnostic efficiency in distinguishing PCa from TZ PI-RADS 3 lesions, while one-way ANOVA analysis was used to examine which parameters were statistically significant among BPH, non-csPCa and csPCa. Results: The logistic model was statistically significant (χ2 = 181.410, p<0.001) and could correctly classify 89.39% of the subjects. Parameters of fractional anisotropy (FA) (p=0.004), mean diffusion (MD) (p=0.005), mean kurtosis (MK) (p=0.015), diffusion coefficient (D) (p=0.001), and distribute diffusion coefficient (DDC) (p=0.038) were statistically significant in the model. ROC analysis showed that AUC was 0.9197 (CI 95%: 0.8736-0.9659). Sensitivity, specificity, positive predictive value and negative predictive value were 92.1%, 80.4%, 93.9% and 75.5%, respectively. FA and MK of csPCa were higher than those of non-csPCa (all p<0.05), while MD, ADC, D, and DDC of csPCa were lower than those of non-csPCa (all p<0.05). Conclusion: FA, MD, MK, D, and DDC can predict PCa in TZ PI-RADS 3 lesions and inform the decision-making process of whether or not to perform a biopsy. Moreover, FA, MD, MK, D, DDC, and ADC may have ability to identify csPCa and non-csPCa in TZ PI-RADS 3 lesions.

Hybrid Ag nanoparticles/polyoxometalate-polydopamine nano-flowers loaded chitosan/gelatin hydrogel scaffolds with synergistic photothermal/chemodynamic/Ag+ anti-bacterial action for accelerated wound healing.

Bacterial infections significantly slow the wound healing process, thus severely threatening human health. Furthermore, traditional antibiotics may promote the development of multidrug-resistant bacteria. Therefore, developing novel bactericides and therapeutic strategies for bacterial infections is important to enhance wound healing. Herein, a three-in-one bactericidal flower-like nanocomposite was assembled using Ag nanoparticles/phosphotungstic acid-polydopamine nano-flowers (AgNPs/POM-PDA). The nanocomposite exhibited photothermal therapy (PTT) when exposed to NIR light via photothermal conversion by PDA. The resultant photothermal effect accelerated and controlled the Ag+ released from AgNPs. The chemodynamic therapy (CDT) was obtained via POM catalytic Fenton-like reaction. The combined PTT/CDT/Ag+ treatment achieved excellent synergistic anti-bacterial activity against both gram-negative E. coli and gram-positive S. aureus. A multifunctional wound dressing was then obtained by embedding the AgNPs/POM-PDA flower-like nanocomposite into the chitosan (CS)/gelatin (GE) biocomposite hydrogel. The synergy of AgNPs/POM-PDA nanocomposites and CS/GE hydrogel remarkably accelerated wound healing in vivo due to the excellent biocompatibility, hydroabsorptivity, and breathability of the hydrogel. In this study, a multifunctional agent was developed to synergistically combat bacterial infections and accelerate wound healing.

Modulation of lncRNA H19 enhances resveratrol-inhibited cancer cell proliferation and migration by regulating endoplasmic reticulum stress.

The phytoalexin resveratrol exhibits anti-tumour activity in many types of cancer. In this study, we showed that resveratrol suppressed the survival of gastric tumour cells both in vivo and in vitro. Resveratrol promoted apoptosis, autophagy and endoplasmic reticulum (ER) stress in a dose-dependent manner. RNA-seq analysis showed that multiple cell death signalling pathways were activated after resveratrol treatment, while the use of ER stress activators (tunicamycin and thapsigargin) in combinatorial with resveratrol led to further inhibition of cancer cell survival. Results also showed that resveratrol altered the expression of several long non-coding RNAs (lncRNAs), including MEG3, PTTG3P, GAS5, BISPR, MALAT1 and H19. Knockdown of H19 in resveratrol-treated cells further enhanced the effects of resveratrol on apoptosis, ER stress and cell cycle S-phase arrest. Furthermore, the migratory ability of resveratrol-treated cells was dramatically decreased after H19 knockdown. In conclusion, resveratrol inhibited cancer cell survival, while knockdown of lncRNA H19 resulted in increased sensitivity to resveratrol therapy.

[Progress in improving the properties of dissolving pulp by enzymes].

Dissolving pulp consists of high purity cellulose and is widely used to as raw materials for the production of regenerated cellulose fiber, cellulose ester and cellulose ether. The characteristic of dissolving pulp affects greatly the production and processing performance of subsequent products. The α-cellulose content, hemicellulose content, pulp viscosity, ash, transition metal ion content, fiber morphology, molecular weight distribution of cellulose and the reactivity are the important properties. Because of its green, mild and high efficiency, the application of enzymes in improving the properties of dissolving pulp has a promising application prospect and has been researched significantly. In this review, the main properties of dissolving pulp are presented first, followed by a recommendation of the enzymes to improve these properties. The application and current research of cellulase and xylanase in improving the properties of dissolving pulp are emphasized. The main problems and the future research areas in improving the properties of dissolving pulp by enzymes are revealed. Finally, the technology prospects in this field are proposed.

Protective Effects of Rocuronium Bromide on Ischemia-Reperfusion Injury in Skeletal Muscle Induced by Tourniquet in Patients Undergoing Elective Unilateral Total Knee Arthroplasty: A Prospective, Double Blind, Randomized, Controlled Study.

PURPOSE: To investigate the effects of different doses of rocuronium on ischemia-reperfusion injury in skeletal muscle induced by tourniquet in patients undergoing elective unilateral total knee arthroplasty. PATIENTS AND METHODS: A total of 90 patients undergoing elective unilateral knee arthroplasty under general anesthesia combined with femoral nerve block were randomly divided into 3 groups: normal saline group (group S), rocuronium 0.6 mg/kg group (group L), and rocuronium 1.2 mg/kg group (group H). The primary outcome was the expression of dystrophin in skeletal muscle at 60 min after ischemia. Secondary outcomes included the concentration of malondialdehyde (MDA) and neuronal nitric oxide synthase (nNOS) in blood at 5 min and 30 min after reperfusion. In addition, thigh girth at 24 h and 48 h after operation, the leaving bed time, the incidence of tourniquet-related hypertension and short-term (3 days after operation) complications (nausea and vomiting, swelling, blister, wound infection) and long-term (3 months after operation) complications (joint instability, stiffness, nerve paralysis, pain) were recorded. MAIN RESULTS: The expression of dystrophin in the rocuronium group was higher than that in group S after ischemia (P <0.05). The concentration of MDA in the rocuronium 1.2 mg/kg group was lower at 30 min after reperfusion (P < 0.05). There was no significant difference in nNOS among groups at each time point (P > 0.05). The change of thigh girth was the smallest in the rocuronium 1.2 mg/kg group after operation (P<0.05). The leaving bed time was significantly earlier after operation in the rocuronium group than that in group S (P <0.05). CONCLUSION: Rocuronium can protect skeletal muscle from ischemia-reperfusion injury induced by tourniquet. The mechanism may be related to the fact that rocuronium can reduce the loss of dystrophin in skeletal muscle and have the effects of anti-oxidation and anti-stress. TRIAL REGISTRATION: The study was registered at http://www.chictr.org.cn (ChiCTR1800019221, registered on 2018-10-31).

Celastrol ameliorates endoplasmic stress-mediated apoptosis of osteoarthritis via regulating ATF-6/CHOP signalling pathway.

OBJECTIVES: Osteoarthritis (OA) is a common degenerative joint disease with the pathological features of the reduced cartilage cellularity. Celastrol, a compound from Tripterygium wilfordii, exerted therapeutic effects on arthritis, but the potential mechanism remains unclear. METHODS: Tunicamycin was used to establish a model of OA in vitro, and ACLT surgery model in rats was applied to verify the mechanism. Chondrocytes were isolated from the knee articular cartilage of rabbit. MTT and flow cytometry assay were used to detect cell viability and apoptosis rate. Haematoxylin-eosin staining was used to assess for the histopathological changes. The activity and expression of apoptosis-related factors and ERs (endoplasmic reticulum stress)-related factors were detected by ELISA, WB, PCR and IHC, respectively. KEY FINDINGS: Celastrol exhibited significant enhancement on cell viability and reduced the rate of apoptosis in Tm-exposed chondrocytes. Celastrol reduced enzyme activity and protein expression of caspase-3, caspase-6 and caspase-9, decreased Bip, Atf6, Chop and Xbp-1 expression both at protein and mRNA levels. Celastrol showed a more significant effect on cell apoptosis rate and mRNA expression in the combination with 4-PBA. CONCLUSIONS: This study reveals that celastrol may prevent OA by inhibiting the ERs-mediated apoptosis. All these might supply beneficial hints for celastrol on OA treatment.

Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Evaluation of the Cell Density and Angiogenesis of Cirrhosis-Related Nodules in an Experimental Rat Model: Comparison and Correlation With Dynamic Contrast-Enhanced MRI.

BACKGROUND: Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and dynamic contrast-enhanced MRI (DCE-MRI) are sensitive imaging modalities for detecting liver lesions, but their value in evaluating cirrhosis-related nodules remains unclear. PURPOSE: To investigate whether IVIM-DWI and DCE-MRI can differentiate different types of cirrhosis-related nodules, and whether these modalities can monitor changes in cell density and angiogenesis during the malignant transformation of cirrhosis-related nodules in a rat model STUDY TYPE: Prospective. ANIMAL MODEL: Thirty-five male Sprague-Dawley rats with 106 cirrhosis-related nodules (19 regenerative nodules [RNs], 47 dysplastic nodules [DNs], and 40 hepatocellular carcinomas [HCCs]). FIELD STRENGTH/SEQUENCE: IVIM-DWI and DCE sequence at 3.0T MRI. ASSESSMENT: IVIM-DWI parameters (D, D*, f, and apparent diffusion coefficient [ADC]) and DCE-MRI parameters (Ktrans , Kep , and Ve ) were calculated by two radiologists using postprocessing software. The "cell density" and "unpaired arterial ratio" were analyzed with a microscope by two pathologists. STATISTICAL TESTS: MRI parameters were compared among the different types of nodules by one-way analysis of variance or the Kruskal-Wallis test. The Pearson correlation test was used to analyze the correlation of MRI parameters with the pathological types of nodules, cell density, and unpaired arterial ratio. RESULTS: The Ktrans , Kep , and Ve values of HCCs were significantly higher than those of DNs and RNs. D and ADC values were significantly lower in HCCs than in DNs and RNs. There were moderate positive correlations of Ktrans with the pathological types of nodules and the unpaired arterial ratio. Moderate negative correlations were observed among D, ADC, and the pathological types of nodules, between D and cell density, and between ADC and cell density. DATA CONCLUSION: IVIM-DWI and DCE-MRI are valuable in differentiating different types of cirrhotic-related nodules. D and ADC are correlated with changes in cell density during the malignant transformation of cirrhosis-related nodules, while Ktrans is correlated with increased angiogenesis. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:812-823.

Fluctuating Sensorineural Hearing Loss.

BACKGROUND: Several otologic conditions can present with fluctuating sensorineural hearing loss, including Ménière's disease, autoimmune inner ear disease, and enlarged vestibular aqueduct. Although these 3 etiologies vary greatly, distinguishing between these conditions at initial presentation can be challenging. Furthermore, initial treatment of these conditions is often similar. In this review, we discuss historical and current perspectives on diagnosis and treatment of these conditions. SUMMARY: A literature search was performed regarding fluctuating hearing loss, and current treatment of these etiologies of fluctuating hearing loss was summarized. Immediate measures at the onset of acute hearing loss include corticosteroid therapy, while preventative and chronic therapies, which can limit disease severity and frequency, vary based on the specific condition treated. Key Messages: Fluctuating hearing loss can represent a range of pathologies, but the precise etiology may not be clear at initial presentation. Timely treatment and long-term follow-up, along with appropriate diagnostics, are necessary to optimize long-term hearing.

[Multi Spectral Detection of Ethanol Content in Gasoline Based on SiPLS Feature Extraction and Information Fusion].

The ethanol content in ethanol gasoline was detected with ultraviolet/visible(UV/vis) and near-infrared (NIR) spectroscopy while information fusion technology and synergy interval PLS(SiPLS) algorithm were used as the feature extraction method with the establishment of partial least squares(PLS) regression model. Using the information fusion theory, UV/vis and NIR spectra were used for data fusion, the data level fusion (Low level data fusion, LLDF) and feature level fusion(Mid-level data fusion, MLDF) model were established. The results were compared with the single source modelwith low level data fusion before vector normalization(LLDF-VN1) selected for the optimal model. Finally, the optimal model was tested using the spectral data collected from the samples of high ethanol content and commercial gasoline. The results showed that both UV/vis and NIR can be used to detect and provide good prediction results, whereas direct fusion of the UV/vis and NIR spectral data provided the best results in the regression model based on the calibration set, with the highest correlation coefficient rc, the smallest Biasc and RMSECV values, as 0.999 9, 0.125 8 and 0.000 6, respectively. And the prediction effect of the model of LLDF-VN1(low level data fusion before vector normalization) was the best, r(p)=0.999 1，Bias(p)=0.352 7，RMSEP=-0.073 8. In the verification of the optimal model (LLDF-VN1) by the self distribution solution, rp=0.999 7, Bias(p)=0.102 2, RMSEP=0.329 1; and that for gasoline sold on market, r(p)=0.990 1, RMSEP=0.675 1, Bias(p)=0.892 7, respectively. It showed that the data level fusion based on UV/vis and NIR spectral information could be used to detect the content of ethanol in ethanol-gasoline quickly and accurately, achieving a wide range of ethanol concentration detection, which laid a foundation for further realization of the rapid detection of substances in the blended fuel oil.

[Comparison of early clinical outcomes between mobile-bearing and fixed-bearing total knee arthroplasty for the valgus knee].

OBJECTIVE: To compare the early clinical outcomes of primary total knee arthroplasty in the valgus knee between mobile-bearing prosthesis and fixed-bearing prosthesis. METHODS: From January 2011 to December 2013, 17 patients (23 knees) treated by the same surgeon were selected for a retrospective study in the First Hospital of Jilin University, including 2 males and 15 females with a mean age of 61.5 years old (48 to 75 years). The pre-operative diagnosis included osteoarthritis (14 patients, 19 knees) and rheumatoid arthritis (3 patients, 4 knees). The patients with valgus deformity were divided into group A and group B. The patients in group A were treated with the fixed-bearing prosthesis (9 patients, 12 knees), and the patients in group B were treated with the mobile-bearing prosthesis (8 patients, 11 knees). The Knee Society Score (KSS), Hosptial for Special Surgery (HSS), Western Ontario MacMaster (WOMAC), the range of motion (ROM) and femorotibial angle were collected at pre-operation and post-operation follow-up for statistical analysis. RESULTS: All the patients were followed up, and the duration ranged from 6 to 36 months (mean 25 months). The valgus deformity was corrected in all patients, and there were significant differences for all patients between pre-operation and post-operation at the latest follow-up with regard to the KSS knee score, function score, HSS score, WOMAC score, ROM and femorotibial angle (P<0.01). There were no significant differences in KSS knee score, function score, HSS score, WOMAC score, improvement in ROM and femorotibial angle between two groups at the latest follow-up. However there were significant differences in ROM (P<0.05) between fixed-bearing group (101.8±8.8)° and mobile-bearing group (108.4±7.2)° at the latest follow-up. No case with spin-out of mobile bearing was observed. There were no complications in any patient, such as infection, common peroneal nerve injury, dislocation and instability. The X-ary imaging showed no osteolysis or implant loosening. CONCLUSION: The early clinical outcomes of primary total knee arthroplasty by using mobile-bearing prosthesis and fixed-bearing prosthesis are satisfactory for the treatment of the valgus knee, and the short term clinical outcomes of mobile-bearing TKA and fixed-bearing TKA are similar.

[Research progress of backside wear in acetabular liners].

OBJECTIVE: To summarize the occurrence mechanism of backside wear, the method of evaluating backside surface damage, the relationship between backside wear and osteolysis in acetabulum, and the approach to reduce backside wear in total hip arthroplasty with modular acetabulum prosthesis. METHODS: The recent articles about the backside wear in acetabular liners were extensively reviewed. RESULTS: Backside wear in acetabular liners is connected with micromotion between the liner and the shell, rough interface, thickness of the liner, and impingement. The methods to evaluate backside wear damage are only proceeded in revised acetabular liners. Backside wear can generate polyethylene particles that is likely related to the process of osteolysis in acetabulum through the screw holes of metallic shell. To reduce backside wear between the liner and the shell, measures such as improved locking mechanisms, smooth inner metallic shell, maximized shell liner conformity, improving the quality of polyethylene, and reducing impingement can be taken. CONCLUSION: There is no method of evaluating the backside wear in vivo. The relationship between backside wear and osteolysis in acetabulum as well as aseptic loosening of acetabulum prosthesis is controversial.

Osteogenic differentiation of bone marrow-derived mesenchymal stromal cells on bone-derived scaffolds: effect of microvibration and role of ERK1/2 activation.

Although in vivo studies have shown that low-magnitude, high-frequency (LMHF) vibration (LM: < 1 ×g; HF: 20-90 Hz) exhibits anabolic effects on skeletal homeostasis, the underlying cellular/molecular regulation involved in bone adaptation to LMHF vibration is little known. In this report, we tested the effects of microvibration (magnitude: 0.3 ×g, frequency: 40 Hz, amplitude: ± 50 µm, 30 min/12 h) on proliferation and osteodifferentiation of bone marrow-derived mesenchymal stromal cells (BMSCs) seeded on human bone-derived scaffolds. The scaffolds were prepared by partial demineralisation and deproteinisation. BMSCs were allowed to attach to the scaffolds for 3 days. Morphological study showed that spindle-shaped BMSCs almost completely covered the surface of bone-derived scaffold and these cells expressed higher ALP activity than those cultured on plates. After microvibration treatment, BMSC proliferation was decreased on day 7 and 10; however, numbers of genes and proteins expressed during osteogenesis, including Cbfa1, ALP, collagen I and osteocalcin were greatly increased. ERK1/2 activation was involved in microvibration-induced BMSC osteogenesis. Taken together, this study suggests that bone-derived scaffolds have good biocompatibility and show osteoinductive properties. By increasing the osteogenic lineage commitment of BMSCs and enhancing osteogenic gene expressions, microvibration promotes BMSC differentiation and increase bone formation of BMSCs seeded on bone-derived scaffolds. Moreover, ERK1/2 pathway plays an important role in microvibration-induced osteogenesis in BMSC cellular scaffolds.

Characterization of MSCs from human placental decidua basalis in hypoxia and serum deprivation.

Recently, we reported that human PDB (placental decidua basalis) is an excellent source of MSCs (mesenchymal stem cells), meanwhile, PDB-MSCs could survive under hypoxia and serum deprivation. Herein, we investigated the proliferation, clonogentic efficiency, phenotypes, metabolic activity and cytokines secretion of PDB-MSCs in hypoxia and serum deprivation. PDB-MSCs were cultured in four groups: normoxia (20% O2) and complete medium [10% FBS (foetal bovine serum)+DMEM-HG (Dulbecco's modified Eagle's medium-high glucose)], hypoxia and complete medium, normoxia and serum deprivation (0% FBS), and hypoxia and serum deprivation. After 96 h of culture in the above groups, PDB-MSCs maintain the phenotypes stably. Interestingly, hypoxia notably enhanced the proliferation, colony-forming potential and lactate/glucose ratio in complete medium, but suppressed the secretion of BMP-2 (bone morphogenetic protein-2) and bFGF (basic fibroblast growth factor), while it did not change the quantity of VEGF (vascular endothelial growth factor) and bFGF in serum deprivation. Although PDB-MSCs grew slowly and seldom formed a colony unit in hypoxia and serum deprivation, they possessed a moderate metabolism. In conclusion, our results indicate that PDB-MSCs appear to be promising seed cells for ischaemia-related tissue engineering.

[Effects of epithelial cell conditioned medium on differentiation of BMSCs].

OBJECTIVE: To investigate the feasibility of inducing canine BMSCs to differentiate into epithelial cells in vitro with epithelial cell conditioned medium (ECCM). METHODS: Five mL BMSCs were obtained from iliac spine of a healthy adult male canine with weighing 10 kg, and then isolated and cultured. The oral mucosa was harvested and cut into 4 mm x 4 mm after the submucosa tissue was eliminated; ECCM was prepared. BMSCs of the 2nd passage were cultured and divided into two groups, cultured in ECCM as experimental group and in L-DMEM as control group. The cell morphological characteristics were observed and the cell growth curves of two groups were drawn by the continual cell counting. The cells were identified by immunohistochemical staining through detecting cytokeratin 19 (CK-19) and anti-cytokeratin AE1/AE3 on the 21st day of induction. The ultra-structure characteristics were observed under transmission electron microscope. RESULTS: The cells of two groups showed long-fusiform in shape and distributed uniformly under inverted phase contrast microscope. The cell growth curves of two groups presented S type. The cell growth curve of the experimental group was right shifted, showing cell proliferation inhibition in ECCM. The result of immunohistochemical staining for CK-19 and anti-cytokeratin AE1/AE3 was positive in the experimental group, confirming the epithelial phenotype of the cells; while the result was negative in the control group. The cells were characterized by tight junction under transmission electron microscope. CONCLUSION: The canine ECCM can induce allogenic BMSCs to differentiate into epithelial cells in vitro.

[Effect of osteoblast conditioned culture medium on differentiation of BMSCs].

OBJECTIVE: To study the effect of rat osteoblast conditioned culture medium on the BMSCs differentiation of allogeneic rat and to find a new approach to provide seed cells for bone tissue engineering. METHODS: BMSCs and osteoblasts were harvested from 10 healthy one-week-old SD rats (male and female, weighing 20-30 g) by adherent method and enzyme digestion method respectively. Cell identification was conducted. Osteoblast conditioned culture medium was prepared by mixing supernatant of osteoblasts at passage 1-5 with complete medium (1:1). Then, BMSCs at passage 2 were co-cultured with osteoblast conditioned culture medium (inducement group) and complete medium (control group), respectively. The morphological changes of co-cultured BMSCs were observed by inverted phase contrast microscope, the growth condition of BMSCs was detected by MTT method, the expressions of ALP, Col I and osteocalcin (OCN) in the co-cultured BMSCs were tested by immunohistochemistry staining, and the expressions of Col I and OCN mRNA were detected by RT-PCR. RESULTS: In the inducement group, BMSCs grew bigger, changing from long fusiform to flat and polygon with protuberance 7 days after co-culture; the presence of cell colony-like growth was observed 9 days after co-culture. Cell growth curve demonstrated that the counts of BMSCs was increased with time, there were more cells in the control group than that of the inducement group, and there was a significant difference in cell counts between the control and the inducement group 4-7 days after co-culture (P < 0.05). For the inducement group, ALP staining was positive 12 days after co-culture, the calcium nodules were appeared 18 days after co-culture, Col I and OCN were positive 21 days after co-culture, and the expressions of Col I and OCN mRNA were detected by RT-PCR 21 days after co-culture. CONCLUSION: Rat osteoblast conditioned culture medium can significantly induce the differentiation of allogeneic rats' BMSCs towards osteoblasts.