USF2 reduces BMP3 expression via transcriptional activation of miR-34a, thus promoting osteogenic differentiation of BMSCs.

INTRODUCTION: Osteoporosis is the most susceptible disease for people over 60. The main cause of osteoporosis is the decreased osteogenic differentiation of mesenchymal stem cells (MSCs). Here we showed that upstream stimulatory factor 2 (USF2)/microRNA-34a (miR-34a)/bone morphogenetic protein 3 (BMP3) axis regulated osteogenic differentiation of BMSCs. MATERIALS AND METHODS: USF2 and miR-34a expression were examined using qPCR. Protein levels of BMP3 and osteogenic markers expression were evaluated using both western blot and qPCR. Activity of ALP was determined by ALP assay kit. Mineralization capacity of hBMSCs was assessed using ARS. Besides, CHIP assay was employed to verify whether USF2 could bind to miR-34a promoter. Finally, RIP assay and dual-luciferase reporter assay were employed to verify whether miR-34a directly bound to BMP3. RESULTS: Our results suggested that miR-34a was upregulated during osteogenic differentiation of BMSCs, and miR-34a overexpression could enhance osteogenic differentiation of BMSCs. USF2 could positively regulate miR-34a expression by interacting with its promoter. USF2 overexpression enhanced osteogenic differentiation of BMSCs, while miR-34a inhibition reversed the effect. Besides, BMP3 was the target of miR-34a. MiR-34a overexpression enhanced osteogenic differentiation of BMSCs, which was abolished by BMP3 overexpression. CONCLUSION: Taken together, USF2 enhanced osteogenic differentiation of BMSCs via downregulating BMP3 by interacting with miR-34a promoter.

Measurements of cardiac efficiency and internal work of the left ventricle via reconstructed impedance cardiography.

Objective. The aim of this study was to investigate methods for measuring the cardiac efficiency (CE) and internal work (IW) of the left ventricle via reconstructed impedance cardiography (RICG).Approach.On the basis of the physiological context and Bernoulli's equation in physics, methods of measuring the CE and IW were proposed. The CE, IW, internal work index (IWI), and other data from 180 healthy adults and 144 patients with cardiovascular disease were measured.Main results. The CE of 180 healthy adults was 22.5 ± 2.2%, and the IWI was 22.3 ± 5.2 J l-1m-2. CE decreased with age, and the CE of the younger group (23.5 ± 1.9%) was larger than that of the older group (21.5 ± 1.9%),P < 0.01. The IWI increased with age, and the IWI of the younger group (19.0 ± 3.8 J l-1m-2) was smaller than that of the older group (24.8 ± 4.3 J l-1m-2),P < 0.01. There were no significant difference in CE (22.4 ± 2.2% and 22.6 ± 2.2%) or in the IWI (21.9 ± 5.1 J l-1m-2and 22.6 ± 5.2 J l-1m-2) between the male and female groups. The CEs and IWIs of patients with hypertension, coronary heart disease, and heart failure were 17.4 ± 2.4% and 41.8 ± 15.6 J l-1m-2, 17.6 ± 3.0% and 35.1 ± 10.4 J l-1m-2, and 15.8 ± 3.5% and 42.1 ± 15.6 J l-1m-2, respectively. These CEs were all smaller than that (21.6 ± 2.0%) of the healthy contrast groupP < 0.01, while the IWIs were all larger than that (24.6 ± 4.8 J l-1m-2) of the healthy contrast group,P < 0.01.Significance.The CEs and IWIs measured in this study may reflect physiological changes in healthy humans and pathogenic conditions in patients with cardiovascular disease.

Artesunate promotes osteoblast differentiation through miR-34a/DKK1 axis.

BACKGROUND: Osteoporosis is characterised by impairment of microarchitecture and bone mass. Therapeutic strategy promoting osteoblast differentiation is considered as a promising direction for the treatment of osteoporosis. Artesunate (ART) is related to osteoporosis, but the relationship between ART and osteogenic differentiation is still unknown. METHODS: Cells proliferation were measured by MTT, ALP activity assay and Alizarin Red S staining were used to assess osteogenic differentiation of hBMSCs. Western blotting and qRT-PCR were applied for measuring expression of protein and mRNA, respectively. The relationship between miR-34a and Dickkopf-1 (DKK1) was detected by dual luciferase reporter assay. RESULTS: The expression of osteoblasts differentiation related proteins (Runx2, OCN, and OPN) were significantly increased by ART. And ART accelerates the osteoblasts differentiation of hBMSCs through promoting Wnt signaling pathway by DKK1 inhibition. Significant higher expression of miR-34a and lower expression of DKK1 could be induced by ART. We firstly proved that miR-34a could bind DKK1 specifically. CONCLUSION: ART could promote osteoblast differentiation through miR-34a/DKK1/Wnt pathway. Therefore, our findings may provide a new thought for the treatment of osteoporosis by ART through osteoblast differentiation promotion.

Effect of the timing of surgery on the fracture healing process and the expression levels of vascular endothelial growth factor and bone morphogenetic protein-2.

The aim of the present study was to observe the effect of varying the timing of surgery on the fracture healing process and the expression levels of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2 in rats. A total of 192 rats underwent closed femur fracture modelling. The rats underwent open reduction and internal fixation surgery 1, 3, 5, 7, 11 and 14 days subsequent to the fracture occurring. Immunohistochemical staining and analysis of the VEGF and BMP-2 expression levels were simultaneously conducted on bone from the fracture site of the rats on various days. The VEGF and BMP-2 expression levels at the fracture sites were higher and were maintained for a longer period of time in the 7- and 11-day surgery groups than in the other surgery groups and the rats that did not undergo surgery. The 5-day surgery group demonstrated a greater intensity in BMP-2 expression compared with the remaining surgery groups; however, no significant differences were identified between 1-day surgery and non surgery groups. In the 3-day surgery group, the expression levels VEGF and BMP-2 were low at each stage of the fracture-healing process and were lower compared with those observed in the non-surgery group. The timing of the surgical procedures affected the VEGF and BMP-2 expression levels at the fracture sites of the experimental rats and, the optimal time for performing surgery was identified to be within the first two weeks. However, surgery may not be conducive to fracture healing if it is performed within the first few days following fracture.

[Effective analysis of continous perfusion with Dandshen and heparin for treatment of femoral head necrosis].

OBJECTIVE: To investigate the effect of continous perfusion with Danshen and heparin for treatment of femoral head necrosis. METHODS: From April 2004 to June 2007,42 patients of femoral head necrosis were treated by contious perfusing with Dandshen and heparin, included 24 males and 18 females with an average age of 39.2 years ranging from 13 to 61 years. There were 18 patients on stage II, 13 patients on stage III, 11 patients on stage IV according to Ficat standard. The venous duct were inserted into femoral head then perfused Danshen and heparin into femoral head for 15 days. Every patient was carried out opacification before treatment and 1 month after operation. Every patient was evaluated according to Harris standard before treatment and 3, 6, 12 months after treatment. RESULTS: All patients were followed-up for 32 to 68 months (means 42.7 months). The average scores of 18 patients on stage II on 3, 6, 12 months after treatment were (88.43 +/- 3.41), (94.37 +/- 3.47), (92.84 +/-4.29), respectively, and the scores after treatment were higher than the score (78.23 +/- 3.47) after treatment. The average scores of 13 cases on stage III on 3, 6, 12 after treatment were (82.94 +/- 3.31), (88.60 +/- 2.31), (86.09 +/- 3.17) respectivly, and the scores after treatment were higher than the score (66.11 +/- 4.50) before treatment. The average scores of 11 cases on stage IV on 3, 6, 12 months after treatment were (61.31 +/- 4.06), (59.2 +/- 7.31), (54.62 +/- 8.20) respectivly,and the scores on 3, 6 months after treatment were higher than the score (50.16 +/- 2.35) before treatment,but there was no obvious difference between before treatment and 12 months after treatment. The rank of phlebography of 18 cases on stage II and 13 cases on stage IlI were improved obvi ously 1 month after treatment,but there was no obvious difference in 11 cases of stage IV. CONCLUSION: The method of contious perfusing with Danshen and heparin into femoral head has the advantage of little damage and good effect. It refers to patients in early stage (II and II ).

[Study on the excitation mechanism of upconversion red emission from Er3+ under square wave excitation].

The rise and decay curves of Er3+ 4F9/2 upconversion emission in oxyfluoride tellurite glass were measured under the excitation at 808 nm from a laser diode driven by square waves. The lifetime of the intermediate state could be determined via rise times. Then the accumulation process of the 4F9/2 population was confirmed. The excitation mechanism of up-conversion red emission under 808 nm excitation was confirmed by the rate equations and analyzing the relationship between the time constants of the rise and decay processes and the intermediate state. Square wave excited upconversion emission may also be used for measuring lifetimes of infrared energy levels with a conventional photomultiplier tube.

[Clinical control study in treating degenerative lumbar instability with single or double carbon fiber cages].

OBJECTIVE: To compare the clinical and radiologic effect in treating degenerative lumbar instability with single or double carbon fiber cages. METHODS: From November 2005 to October 2006, 97 patients of degenerative lumbar instability were followed up more than two years. All cases underwent pedicle screw fixation. Meanwhile, 41 of them, named group A, were applied with single carbon fiber cage, with 23 males and 18 females, aged for 35-70 years, including 38 cases with single vertebral instability and 3 cases with existing L4.5 and L5S1 intervertebral instability. The other 56 cases, named group B, were treated with two carbon fiber cages, with 32 males and 24 females, aged for 33-72 years, including 53 cases with single vertebral instability and 3 cases existing L4.5 and L5S1 intervertebral instability. The clinical effect, intervertebral fusion ratio and lost intervertebral height were compared between two groups. RESULTS: All patients were followed up for 24-35 months, with an average of 28 months. Clinical effects (including symptom, sign, daily action and bladder function) were evaluated according to JOA 29 score. In group A: the JOA score improve from 10.11 +/- 2.40 preoperative to 24.88 +/- 2.30 at final follow-up, 25 cases obtained excellent results, 12 good, 4 fair; 39 cases obtained fusion with the fusion ratio of 95.1% (39/41). In group B: the JOA score from 9.62 +/- 2.60 preoperative to 25.19 +/- 2.40 at final follow-up, 37 cases obtained excellent results, 13 good, 6 fair; 53 cases obtained fusion with the fusion ratio of 94.6% (53/56). In the 7th day after operation, the average intervertebral height in group A was (11.2 +/- 1.2) mm,and that of group B was (11.3 +/- 1.4) mm. Two years later, the average intervertebral height in group A was (11.0 +/- 1.4) mm, while that of group B was (11.1 +/- 1.4) mm. There was no significant difference between two groups in clinical effect, intervertebral fusion ratio and lost intervertebral height (P > 0.05). CONCLUSION: Pedicle screw fixation and single or double carbon fiber cages in treating degenerative lumbar instability both can obtain satisfactory curative effect. Single carbon fiber cage has advantages such as minimally trauma, simply operation, retentively posterior column structure, cheaply price than double carbon fiber cages.

[Effect of static magnetic field on deep wound healing of SD rats].

OBJECTIVE: To investigate the effect of static magnetic field on deep wound healing of SD rats and VEGF during the wound healing and different strength static magnetic field on deep wound healing of SD rats. METHODS: Divided forty-eight SD rats into three groups: 0.16 T magnetic disk treatment (0.16 T group), 0.32 T magnetic disk treatment (0.32 T group), control group. General wounds healing situation was observated on the 3, 6, 9, 12 day. The area of every wound was calculated. The tissue of granulation was dyeing by immune tissue chemical decoration method, in which VEGF protein content with its range in tissue was measured. RESULTS: The healing index of 0.16 T magnetic group wounds were larger than that of control group on 6th and 9th day, there were statistical difference. The healing index of 0.32 T magnetic group wounds were larger than that of control group on 3rd, 6th, 9th and 12th day, there were statistical difference. The healing index of 0.32 T group wounds contrasted to that of 0.16 T group wounds had no statistical significance. Observation of VEGF at the course of wound healing:the expressing of VEGF in magnetic group wounds on 3rd and 6th was stronger than in control group wounds, there were statistical difference. While there were no obvious difference between them on 9th and 12th day (P>0.05). But the contrast between that in 0.32 T group and in 0.16 T group had no statistical difference. The expressing strength of VEGF in magnetic group reached the peak amplitude on the 6th day, and that in control group reached peak amplitude on 9th day. And the peak amplitude of magnetic group was stronger than that of control group. CONCLUSION: Static magnetic disc of 0.16T and 0.32 T can promote deep wound of SD rats heal. The mechanism of static magnetic field promoting wound heal may be relative to the expressing highly of VEGF during early and middle time.

[Electrooptical properties of nanoscale and bulk SrAl2O4: Eu, Dy].

Nanoscale and bulk SrAl2O4 : Eu2+, Dy3+ were prepared respectively by auto-combustion of citrate gelatin and high temperature solid state method. The crystalline structure was examined by X-ray diffraction (XRD). The current-voltage characteristic was measured with a Keithley source meter 2 410. The VUV spectra were carried out with VUV spectrometer. There-result showed that light irradiation increased the current, which indicates that some electrons are excited to the conduction band of host lattice. VUV excitation spectrum of nanoscale SrAl2O4 : Eu2+, Dy3+ shifts to the shorter wavelength relative to bulk material because it has narrower bandgap. As a result, the current of nanoscale material is weaker than that of the bulk one.

[Surgical treatment for the intradural extramedullary tumor in the spinal canal].

OBJECTIVE: To study the clinical characteristics of the intradural extramedullary tumor in the spinal canal, as well as the application of internal fixation technique to restore the spinal stability in the surgical treatment of intradural extramedullary tumor in the spinal canal through posterior approach. METHODS: Among 24 patients receiving the tumor resection through posterior approach, 14 patients were male and 10 patients were female, ranging in age from 12 to 68 years, with an average of 40 years. Fourteen patients were treated with internal fixation and autogenous bone graft after tumor resection, and other 10 patients without internal fixation and autogenous bone graft. RESULTS: All the patients underwent one-stage resection of the tumor. During the follow-up period ranged from 6 months to 3 years (average 22 months), no recurrence of the tumor was found and the injury of spine cord did not aggravate, no vascular or nerve-root injury after the operation. The Frankle grades were improved by 1 to 3 degrees. Bone fusion formed at the corresponding bone grafted place. And there was no instrument broken or loosening. CONCLUSION: After the intradural extramedullary tumor is resected, internal fixation and autogenous bone graft can restore the stability of spine.