AIM:To investigate the effect of different oxygen concentrations on the differentiation of marrow stroma cells into osteoblasts and to evaluate the expression of Cbfα1 /Runx2,bone-morphogenesis protein 2 (BMP2) and peroxisome proliferator-activated receptor γ2 (PPAR-γ2) in bone marrow stromal cells. METHODS:The bone marrow stomal cells obtained from 4-month-old female SD rats were cultured in growth medium and were used between passages 3 to 5. The cells were divided randomly into 4 groups,each group has 8 samples. The cells in all 4 groups were used for the following experiments after cultured with different oxygen concentrations for 3 d in osteoblastic differentiation medium:total cellular RNA was isolated using total RNA kit; RT -PCR was performed to detect the mRNA expression of Cbfα1 /Runx2,BMP2 and PPARγ2. The protein expression of Cbfα1 /Runx2 and BMP2 was assayed by Western blotting. RESULTS:Compared to the cells in normoxia condition (20% ),the mRNA and protein expressions of Runx2 were enhanced significantly,the mRNA expression of BMP2 was also enhanced significantly,the protein expression of BMP2 increased and the mRNA expression of PPARγ2 decreased significantly in the cells cultured with lower oxygen concentrations. The lower oxygen con-centration was in the culture,the more Runx2 mRNA,BMP2 mRNA,BMP2 and Runx2 protein were expressed. On the contrary,hypoxia significantly decreased the expression of PPARγ2 mRNA in bone marrow stronmal cells and the lower the oxy-gen concentration was used,the less expression of PPARγ2 mRNA was achieved. CONCLUSION:Hypoxia promotes the mRNA and protein expressions of Runx2 and BMP2,also significantly decreases the expression of PPARγ2 mRNA in bone marrow stronmal cells in an oxygen concentration dependent manner,indicating that hypoxia significantly stimulates the differentiation of bone marrow stromal cells into osteoblasts instead of lipocytes.
Background/Aims: Excessive salt intake and left ventricular hypertrophy (LVH) are both critical for the development of hypertension and heart failure. The uncoupling protein 3 (UCP3) plays a cardio-protective role in early heart failure development. However, the potential role for UCP3 in salt intake and LVH is unclear. Methods: UCP3-/- and C57BL/6 mice were placed on either a normal-salt (NS, 0.5%) or a high-salt (HS, 8%) diet for 24 weeks. The cardiac function, endurance capacity, energy expenditure, and mitochondrial functional capacity were measured in each group. Results: Elevated blood pressure was only observed in HS-fed UCP3-/- mice. High salt induced cardiac hypertrophy and dysfunction were observed in both C57BL/6 and UCP3-/- mice. However, the cardiac lesions were more profound in HS-fed UCP3-/- mice. Furthermore, HS-fed UCP3-/-mice experienced more severe mitochondrial respiratory dysfunction compared with HS-fed C57BL/6 mice, represented by the decreased volume of oxygen consumption and heat production at the whole-body level. Conclusion: UCP3 protein was involved in the incidence of high-salt induced hypertension and the progression of cardiac dysfunction in the early stages of heart failure. UCP3 ablation exacerbated high-salt-induced cardiac hypertrophy and cardiac dysfunction.
Objective:To study the relationship between body composition and bone mineral density(BMD) in postmenopausal women with type 2 diabetes mellitus(DM).Methods:62 postmenopausal women without DM(NDM group) and 48 postmenopausal women with DM(DM group) were scanned by dual-energy X-ray absorptiometry(DEXA) for examination of L1～L4 normotopia,left hip,whole body BMD and body composition.The results were analyzed and compared between the two groups finally.Results:(1) The BMD of left femurs,lumbar spine(L1～L4) and whole body as well as body composite of whole body,trunk and left leg had no significant differences between the two groups.(2) In DM group,fat tissue mass(FTM) of whole body,lean tissues mass(LTM) of whole body and FTM of trunk were positively correlated with BMD of the lumbar spine and BMD of whole body,respectively.LTM of whole body,FTM and LTM of trunk were significantly positive correlated with BMD of left femur and whole body,respectively.(3) In NDM group,FTM of whole body,LTM of whole body and FTM of trunk were positively correlated with BMD of whole body,lumbar spine and whole femur except Ward's triangular area(P0.01～0.05) respectively,but LTM of trunk was only positively correlated with BMD of troch.Conclusion:Body composition and BMD in postmenopausal women with DM are of certain correlations that are different from those without DM.These differences may be related to metabolic disorders induced by DM.
The direct torque control theory has achieved great success in the control of induction motors. However, in the DTC drive system of Permanent Magnet Synchronous Machine (PMSM) proposed a few years ago, there are many basic theoretical problems that must be clarified. This paper describes an investigation about the effect of the zero voltage space vectors in the DTC system of PMSM and points out that if using the zero voltage space vectors rationally, not only can the DTC system be driven successfully but also the torque ripple is reduced and the performance of the system is improved. This paper also studies the sensorless technique in the DTC system of PMSM and configures the DTC system of PMSM with sensorless technique including zero voltage space vectors. Numerical simulations and experimental tests have proved the theory correct. In the condition of sensorless, the DTC system of PMSM is wide-rangely speed adjusting, and the ratio of speed adjustment is 1:100.
MicroRNAs (miRNAs) have been implicated in a variety of physiological processes, however, the function of miRNAs in insulin secretion and type 2 diabetes is still unclear. Stxbp1 plays an essential role in exocytosis, and is crucial for insulin secretion. In this study, we focused on the molecular mechanism of Stxbp1 in insulin secretion by identifying its upstream regulators: miR-218 and miR-322. The expression of Stxbp1 was significantly increased in isolated mouse islets exposed to high levels of glucose within 1 h; while two of its predicted upstream miRNAs were found to be downregulated. Further study found that miR-218 and miR-322 directly interact with Stxbp1 by targeting the 3'UTR of its mRNA. MIN6 cells overexpressing the two miRNAs showed a sharp decline in insulin secretion and a decreased sensitivity to glucose; while the inhibition of the two miRNAs promoted insulin secretion. However, islets treated with prolonged high levels of glucose, which is known as glucolipotoxicity, displayed relatively high expression of miR-218 and miR-322, and a reduced level of expression of Stxbp1 accompanied by the blocking of insulin secretion. In summary, this study identified a pathway consisting of miR-218/322 and Stxbp1 in insulin secretion, contributing to a network of β-cell function involving miRNA.
To explore the joint diagnostic value of four temperature sensation tests in elderly patients with type 2 diabetic peripheral neuropathy.Thermal sensory analyzer-II were applied to measure cool sensation (CS), warm sensation (WS), cold pain sensation (CP)and heat pain sensation (HP) of 308 elderly patients with type 2 diabetes. Logistic regression model was adopted to create the new variable Temp4 from four temperature sensation tests to diagnose type 2 diabetic peripheral neuropathy. The ROC curve analysis was used to determine the best cut-off points of the four temperature sensation and Temp4, and the diagnostic value of it was evaluated.The means of temperature sensation tests of the diabetic peripheral neuropathy (DPN) group were significantly different from those of the non-DPN group (P < 0.05). According to the current reference intervals of the four temperature sensation tests to diagnose the DPN, the sensitivity of WS test was the highest, and the value was 0.710; but the specificity, positive predictive value, negative predictive value, Youden index, diagnostic accuracy and Kappa value of cold sensation test were the highest, and the values were 0.842, 0.746, 0.799, 0.528, 77.92% and 0.535, respectively; the Kappa values of the other three temperature sensation tests were all greater than 0.4 (P < 0.05). The area under the ROC curve of the new variable Temp4 was 0.93 (95% CI 0.91-0.96), and was larger than the four temperature sensation tests (P < 0.05). The sensitivity, specificity, Youden index and diagnostic accuracy of Temp4 were 0.823, 0.897, 0.719 and 86.69%, respectively. The new best cut-off points of the CS test, WS test, CP test, HP test and Temp4 was 27.5 degrees C, 34.7 degrees C, 20.5 degrees C, 43.5 degrees C and 0.416, respectively.The results of the four temperature sensation quantitative tests were in good agreementand could be applied to diagnose DPN; the new variable Temp4 could be used for diagnosis of DPN with a higher diagnostic accuracy.
To evaluate the clinical effectiveness and safety of autologous platelet-rich gel (APG) in the treatment of chronic skin ulcer with tophus.Four patients of chronic skin ulcer with tophus received routine debridement to remove necrotic tissue and erasion tophus as far as possible,and then received the treatment of APG.All of the patients had their wounds healed after the treatment of APG (one wound was treated twice). The wounds were healed between 8 to 22 d, average (13. 7±6. 8) d, while there were no adverse effects observed.Topical therapy with APG may be considered as an effective and safe adjuvant method for the treamtment of chronic skin ulcer with tophus.
There exits a problem that the zero-voltage-switching (ZVS) Phase-Modulated full bridge Converter (PMC), which is usually used at medium and high power levels, is hard to keep ZVS in the delayed bridge leg. This paper points out the root of the above problem and gives many solutions it. Two kinds of novel circuit are mainly studied in this paper, one is a topology that adopted switches in the secondary side, and the other introduces a saturable inductor to its circuit. Both of them can effectively achieve ZVS as the delayed leg switch undergoing turn on/off, hence extend the ZVS range with a great load alteration, at the same time suppress the voltage and current spikes very well. In addition, circuit parameter design and duty loss including the comparison of the two circuit topologies are discussed in detail. The proposed theory is proved through the experimental results.
Patients with hypopituitarism often develop chronic hyponatremia,and osmotic demyelination syndrome(ODS) is seldom happened during the treatment.Two cases with hypopituitarism occurred ODS were reported here and the reasons were analyzed.Overly rapid correction of chronic hyponatremia can lead to ODS.The prevention of ODS is the key.Currently,there is not special treatment,and combining treatment is needed.
Key words:
Osmotic demyelination syndrome; Hypopituitarism; Hyponatremia
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