Abstract BACKGROUND: Sodium hyaluronate is an effective treatment for osteoarthritis, but the underlying mechanism remains unclear. There is evidence that abnormal expressions of matrix metaloproteinase (MMP)-1, -3 and -9 and tissue inhibitor of metaloproteinase (TIMP)-1 and -2 show great effects on osteoarthritis. OBJECTIVE: To assess the influence of intra-articular injection of sodium hyaluronate on expressions of MMPs-1, 3, 9 and tissue inhibitor of TIMPs-1, 2 in the rabbit cartilage after osteoarthritis. METHODS: Twenty-four mature New Zealand white rabbits were divided into normal control, model, and sodium hyaluronate groups. The model and sodium hyaluronate groups underwent unilateral anterior cruciate ligament transection, and rabbits in the sodium hyaluronate group received 0.3 mL of 1% sodium hyaluronate via intra-articular injection at 4 weeks after modeling, once a week for 5 weeks. At 11 weeks folowing surgery, the rabbits were kiled and the cartilage was harvested to extract total RNA. mRNA expressions of MMPs-1, 3, 9 and TIMPs-1, 2 in the cartilage were analyzed using real-time PCR for each group. RESULTS AND CONCLUSION:Compared with the model group, the range and extent of cartilage damage was reduced in the sodium hyaluronate group (P < 0.01), and Mankin scores were noticeably decreased (P < 0.05). In the cartilage, mRNA expressions of MMPs-1, 3, 9 were enhanced and mRNA expressions of TIMPs-1, 2 were down-regulated in the model group. However, the mRNA expression levels of MMPs-1, 3, 9 and TIMPs-1, 2 in the articular cartilage were not obviously changed in the sodium hyaluronate group. These results suggest that MMPs-1, 3, 9 and TIMPs-1, 2 are involved in the progression of osteoarthritis and the therapeutic mechanism of sodium hyaluronate is not realized through the down-regulation of their expressions during development of osteoarthritis. Sodium hyaluronate for treatment of osteoarthritis is a complex process and the underlying mechanisms require further investigation.

The effect of inhibition of proliferation of a novel human megakaryoblastic leukemia cell line (HIMeg) by two physiological factors, 1.25-dihydroxyvitamin D3 [1,25(OH)2 D3] and 13-cis-retinoic acid (RA), was investigated. At the range of 10-9 - 10-6 mol/L, 1,25(OH)2 D3 and RA showed significant inhibition of proliferation of the megakaryoblastic leukemia cells,which was demonstrated by count of survival cells,incorporation of [3H]-TdR and [3H]-UR, and cloning efficiency. From above, it can further explain the m.echanism of differentiation-inducers and the effect of 1,25(OH)2D3 on myelofibrosis. It is possible for 1,25(OH)2D3 and RA to be used for a new -treatment.

Objective To explore the change of venous blood phase values detected by enhanced gradient echo T2 star weighted angiography(ESWAN)sequence in mild and severe traumatic brain injury (TBI) models of rabbits in diverse phases and investigate their association with neurological severity scale (NSS) scores. Methods Fifty-one New Zealand rabbits, which were randomly divided into control group (n=3) ,mild injured group (n=24) , and severe injured group (n=24) by random digital table method, underwent routine MRI and ESWAN sequence at the time points of baseline, 1 h, 6 h, 12 h, 24 h, 48 h, 72 h, 1 week, and 2 weeks after injury(3 rabbits per subgroup)respectively. Blood phase values in veins of interest were recorded. Observation of behavior characteristics and abnormalities, followed by NSS, was executed post injury, and the correlation between venous blood phase values and NSS scores was statistically analyzed. Two independent-samples t-test was applied to compare venous blood phase values of diverse measured veins in each group separately at every time ponits. One-way ANOVA was used to analyze venous blood phase values varying over time of measured vessels in each injured group. Least significant difference t-test was applied to compare blood phase values within the subgroups with each other at each time point. NSS scores of mild and severe injured groups were compared by two independent-samples t-test. Correlations between venous blood phase values and NSS scores in each vein and group was analyzed with Spearman correlation analysis. Results Blood phase values in veins of interest presented an inclination of descending, which was more obvious in severe injured groups than in the mild. Change of venous blood phase values over time featured continuing reduction in earlier phases which reached to the minimum in 24-48h, and then increased gradually, especially in VMV, VLV, DSS, and MDVB (P<0.05). ICV and DCV also showed similar trend. Values of NSS scores in the two group were (15.5 ± 3.1) and (33.2 ± 6.5) respectively (t=3.543,P=0.001). Blood phase values in most of the measured veins correlated with NSS scores (P<0.05) after 6h post injury, especially significant during 24-72h among all the measured veins(P<0.05). Higher accuracy and sensitivity were presented in the supratentorial or superficial veins compared with subtentorial or profound veins. Conclusions It is feasible to evaluate oxygen saturation of veins after TBI by measuring venous blood phase values on ESWAN images. The method is effective in the assessment of the degree of injury and clinical status, indicating a favorable application prospect.

Objective To investigate dynamic regulation of quantifying fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in rotational brain injury models of rabbit using diffusion tensor imaging (DTI), and its correlation with β?amyloid precursor protein (β-APP). Methods Forty-two 6-month-old New Zealand rabbits were randomly divided into three groups, including control group (n=6), mild injured group (n=18) and severe injured group (n=18), and preformed on autonomous rapidly rotational brain injury device. The rotational angles of 45° for mild injured group and 90° for severe injured group were condemned, and MRI and pathology were conducted at 6 h, 12 h, 24 h, 48 h, 72 h and 1 week after injury (3 rabbits per subgroup). Routine sequences and DTI technique were performed on 3.0 T MRI. FA and ADC values in subcortical white matter, corpus callosum and brain stem were measured. Independent t?test was performed to evaluate the significance of the intergroup difference in FA and ADC values in mild and severe injured groups of verious brain regions by timing, one?way ANOVA was performed to evaluate its timing variation and its correlation with the number of the β-APP positive axons was analyzed by Pearson correlation analysis. Results FA and ADC values of the severe injured group were lower than that of the mild in most brain regions(P<0.05), and the difference in mild injured group was smaller than that in severe injured group. Both FA and ADC values in brain stem of the severe injured group were lower at 6 h after injury compared to mild injured group, which were sensitive to injury. Furthermore, FA and ADC values in each brain regions of mild and severe injured groups showed similar dynamic trends, namely gradually decreasing by time, and FA values were more sensitive to injury than ADC values. FA values in subcortical white matter and brain stem reduced in severe injured group at 6 h after injury compared with that before injury(P<0.05), and decreased in various brain area of both injured groups at 12 h after injury(P<0.05). Meanwhile, ADC values in all regions were declined in the severe injured group at 12 h after injury(P<0.05), and decreased in various regions in both injured groups at 24—48 h after injury(P<0.05)except for subcortical white matter in mild injured group. There were statistically negative correlations between FA and ADC values and the number of β-APP positive axons in 12—48 h after injury in most regions(P<0.05). Conclusions DTI can quantitatively detect and assess the pathological process in white matter and axons of TBI in earlier stage of the brain injury, and can be applied in evaluation and quantitative diagnose in these patients.

Objective To explore the signaling pathway of apoptosis induced by Paclitaxel (PTX) in leukemia cells and the chemosensitizing effect of adding short hairpin RNA(shRNA) on PTX,which targets the silencer of death domains(SODD).Methods After being treated with PTX,the expressions of SODD,B-cell lymphoma/leukemia-2 (Bcl-2),nuclear factor kappa B (NF-κB) and Caspase-3 proteins in Jurkat cells were determined by Western blot ;the shRNA-SODD vectors were constructed and transfected into Jurkat cells by electroporation,and then G418 was used to select the stable tranfected cell line expressing the shRNA-SODD recombinant plasmids.The incidence of cell apoptosis induced by PTX was determined by flow cytometry labeled with propidium iodide.Results During the process of inducing apoptosis of Jurkat cells,PTX could significantly down-regulate the expressions of SODD and Bcl-2 proteins,degrade Caspase-3 and activate NF-κB.The apoptotic sensibility of Jurkat cells transfected with shRNA-SODD to PTX was significantly increased compared with the control group,and the difference was statistically significant (F =10.35,P ＜ 0.05).Conclusions PTX can effectively induce apoptosis of Jurkat cells.Perhaps,SODD/Bcl-2 represents a specific apoptotic signaling pathway of PTX in leukemia cells and this apoptotic signaling pathway is Caspase-3-dependent,in which the function of NF-κB is to modulate the correlative apoptotic factors.Inhibiting the expression of SODD through transfecting shRNA-SODD vectors can significantly increase the apoptotic sensibility of leukemia cells to PTX.

BACKGROUND:Studies have found that vascular endothelial growth factor and hypoxia inducible factor are involved in the development process of osteoarthritis, but their correlation is rarely reported. OBJECTIVE:To observe the expression and correlation of hypoxia inducible factor-2α and vascular endothelial growth factor in chondrocytes of articular cartilages in human osteoarthritis. METHODS: Articular cartilage specimens were colected from 50 patients with knee osteoarthritis undergoing total knee joint replacement. According to the joint Kelgren-Lawrance (K-L) X-ray grouping classification standard, there were 18 cases of K-LIII level and 32 cases of K-LIV level. Besides, articular cartilage specimens from 10 patients undergoing amputation for legs tumor or traffic accident served as control group. Hematoxylin-eosin staining, Safranin O-Fast Green staining and Mankin scoring were performed to observe and evaluate the histological characteristics of articular cartilages of each group, immunohistochemical staining was conducted to detect the expression of hypoxia inducible factor-2α and vascular endothelial growth factor in chondrocytes of articular cartilages, and their correlations were analyzed. RESULTS AND CONCLUSION:The Mankin score of K-LIV group was significantly higher than those of K-LIII group and control group. Immunohistochemical staining revealed that the number of chondrocytes with positive expression of hypoxia inducible factor-2α or vascular endothelial growth factor in K-LIV group was significantly higher than that in K-LIII group and control group (P < 0.05). The expression of hypoxia inducible factor-2α and vascular endothelial growth factor increased in chondrocytes of articular cartilages of osteoarthritis patients, and to up-regulate the expression of vascular endothelial growth factor may be the regulatory mechanism of hypoxia inducible factor-2αinthe pathogenesis of osteoarthritis.

BACKGROUND:In recent years, repair of articular cartilage injury has become an important field in basic medical research. Because injured articular cartilage is difficult to repair, the repair of articular cartilage injury has become a difficult hotspot.

BACKGROUND:Mesenchymal stem cels, underin vivo orin vitro specific induction conditions, can differentiate into the cartilage, muscle, tendons and so on. Clinical trials concerning mesenchymal stem cels mainly include tissue repair (such as bone, cartilage and joint repair) and treatment of heart, liver, spinal cord injury and nervous system diseases.
OBJECTIVE:To compare the biological characteristics of mesenchymal stem cels from different sources.
METHODS: PubMed and CNKI databases were retrieved for articles related to sources of mesenchymal stem cels and biological characteristics of mesenchymal stem cels published from 1987 to 2015. The retrieved articles were summarized and analyzed in the folowing aspects: cel surface marker, proliferation, differentiation, migration, and function, so as to explore the merits and demerits of mesenchymal stem cels from different sources.
RESULTS AND CONCLUSION:A difference in the proliferation ability and surface markers is found between different sources of mesenchymal stem cels. Immunological competence of mesenchymal stem cels from different sources may be correlated with their activation status, species differences, tissue sources and culture conditions, resulting the immunological competence of mesenchymal stem cels from different sources is not exact the same. In-depth understanding of the factors and mechanisms by which influence the migration of mesenchymal stem cels from different sources can enhance the migration ability of different sources of mesenchymal stem cels, and increase their efficiency in wound healing, tissue repair and regeneration treatment.

The expression of silence of death domains (SODD) and its clinical significance and relationship with phospho-NF-kappaB-p65 proteins in bone marrow cells of childhood acute lymphoblastic leukaemia (ALL) were explored, and the expression of SODD and phospho-NF-kappaB-p65 in Jurkat cells treated with chemotherapeutic drugs was detected in order to find a new chemotherapeutic target. The expression of SODD and phospho-NF-kappaB-p65 proteins in bone marrow cells was detected by immunohistochemistry in 25 children with ALL. The apoptosis rate was measured by Annexin-V-Fluorescence/PI double-labeling flow cytometry and the expression of SODD and phospho-NF-kappaB-p65 proteins determined by Western blotting in the Jurkat cells. It was found that the expression of SODD and active P65 in ALL was significantly higher than that in normal control group (P<0.05). The expression of the SODD and phospho-NF-kappaB-p65 proteins in the high-risk (HR) group was significantly higher than that in the standard-risk (SR) group (P<0.05). The Pearson rank correlation analysis revealed that there was a positive correlation between SODD and phospho-NF-kappaB-p65 expression (P<0.01, r=0.69). VCR could effectively induce the apoptosis of Jurkat cells, and down-regulate the expression of SODD and phospho-NF-kappaB-p65 proteins in a time-dependent manner, but DNR could not down-regulate the expression of SODD effectively. It was concluded that SODD may be closely related to the clinical classification and prognosis of ALL in children. The expression of SODD and phospho-NF-kappaB-p65 had a definite synergistic relationship with the onset and development of ALL. VCR could down-regulate the expression of SODD and inhibit the NF-kappaB activation, which could recover the sensibility of apoptosis in leukemic cells.

BACKGROUND:Osteoarthritis is a joint disease that primarily affects the cartilage. With the changes of the extracelular matrix, chondrocytes appear to have apoptosis. Vascular endothelial growth factor plays an important role in promoting endothelial cel division and proliferation and inducing angiogenesis. Hypoxia-inducible factor is a celular transcription factor and produces different reactions due to the oxygen content. Vascular endothelial growth factor and hypoxia-inducible factor are focused on inhibiting chondrocyte apoptosis. OBJECTIVE:To elaborate the effects of vascular endothelial growth factor and hypoxia-inducible factors on chondrocyte apoptosis. METHODS: Recent literatures related to chondrocyte apoptosis were summarized and analyzed. During the process of osteoarthritis, changes in vascular endothelial growth factors in chondrocytes and regulatory effects of vascular endothelial growth factor and hypoxia-inducible factor on chondrocyte apoptosis were elaborated.