ABSTRACT
BACKGROUND: Preliminary study has shown that the composite materials composed of magnesium-based materials and mineralized collagen have a good supporting effect on repairing the critical defects, which can improve the mechanical strength of mineralized collagen and premature collapse during bone healing to some extent. However, magnesium-based metals degrade fast in chloride-containing solutions (including human body fluids or plasma), and the effects of releasing magnesium ions on the proliferation and differentiation of osteoblasts are unknown. OBJECTIVVE: To investigate the effects of magnesium ion combined with mineralized collagen on osteogenic differentiation of mouse preosteoblasts in vitro. METHODS: Mineralized collagen extracts were prepared from complete medium with magnesium ion concentration of 0, 5, 10, and 20 mmol/L. Mouse preosteoblasts were cultured with four mineralized collagen extracts, respectively, which were divided into mineralized collagen group, and 5, 10 and 20 mmol/L Mg2++mineralized collagen groups. The mouse preosteoblasts cultured in complete medium were used as control group. The cell morphology, proliferation, apoptosis, intracellular microfilament actin, and the activity of alkaline phosphatase and expression level of the osteogenic gene Runx2 after osteogenic differentiation were detected. RESULTS AND CONCLUSION: (1) After 24 hours of culture, the cells in the mineralized collagen group, and 5 and 10 mmol/L Mg2++ mineralized collagen groups adhered well, which showed no significant difference from the blank control group, and the elongated spindle cells with many synapses linked to the adjacent cells were observed. The cells in the 20 mmol/L Mg2++mineralized collagen group showed obvious pyknosis. (2) After 1, 3 and 5 days of culture, the cell viability in the 10 mmol/L Mg2++mineralized collagen group was significantly higher than that in the other four groups (P 0.05). The cell viability in the 20 mmol/L Mg2++mineralized collagen group was significantly lower than that in the mineralized collagen group (P < 0.05). (3) After 3 days of culture, DAPI staining showed that 20 mmol/L Mg2++mineralized collagen group had obvious nuclear disintegration, the other four groups had no obvious nuclear disintegration. (4) After 24 hours of culture, phalloidin staining showed that except the blank control and 20 mmol/L Mg2++mineralized collagen groups, the other three groups showed completely extended cell structure, and clear actin microfilaments, especially the 10 mmol/L Mg2++mineralized collagen group. (5) After 7 days of osteogenic differentiation, except for 20 mmol/L Mg2++mineralized collagen group, the activity of alkaline phosphatase and the expression level of Runx2 gene in the other three groups were significantly higher than those in the blank control group (P < 0.05), and those in the 10 mmol/L Mg2++mineralized collagen group was significantly higher than those in the 5 mmol/L Mg2++mineralized collagen and mineralized collagen groups (P < 0.05). (6) These results suggest that the combination of magnesium ion with mineralized collagen should be applied with appropriate concentration range of magnesium ion (≤ 10 mmol/L).
ABSTRACT
<p><b>OBJECTIVE</b>To explore the relationship between fasting C-peptide (F-CP) and serum uric acid (SUA) in patients with type 2 diabetes mellitus (T2DM).</p><p><b>METHODS</b>A total of 347 hospitalized patients with T2DM were stratified according to F-CP level to analyze the impact of increased F-CP levels on SUA level and the incidence of hyperuricemia (HUA). The patients with an elevated SUA level (>420 µmol/L) and a normal SUA level (≤420 µmol/L) were compared for general data, fasting C-peptide and other clinical indexes. Pearson or Spearman correlation analysis was used to analyze the correlation of SUA level with F-CP levels and other parameters. The risk factors of elevated SUA were analyzed by binary logistic regression, multiple regression analysis and hierarchical interaction analysis. The ROC curve was used to analyze the independent risk factors of elevated SUA and determine the corresponding cut-off values.</p><p><b>RESULTS</b>Compared with those with a normal SUA level, patients with elevated SUA had higher body mass index (BMI), waist-to-hip ratio, F-CP, postprandial 2hC peptide (2hP-CP), triglyceride (TG), homocysteine (HCY), serum creatinine (SCr) level (P<0.05), and a greater percentage of drinking (44.8% vs 32.6%, P=0.006), but had significantly lowered levels of HbA1c, high-density lipoprotein (HDL), and estimated glomerular filtration rate (eGFR) (P<0.05). SUA was found to be positively correlated with F-CP, 2hP-CP, BMI, waist-to-hip ratio, diastolic blood pressure, TG, HCY, SCr, smoking and drinking (P<0.05), and was negatively correlated with gender, age, age of disease onset, HbA1c, HDL and eGFR (P<0.05). SUA level and the incidence of hyperuricemia increasea significantly with F-CP level (P<0.05). F-CP was identified as an independent risk factor for elevated SUA, and gender did not affect the relationship between F-CP and SUA. ROC curve analysis showed that a F-CP level >1.260 ng/mL was associated with a significantly increased risk of hyperuricemia in T2DM patients.</p><p><b>CONCLUSION</b>F-CP is closely related with SUA and may be an independent risk factor of elevated SUA in patients with T2DM.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To compare the value of the new national criteria (2 major or one major plus 3 minor criteria) with the Duke criteria for diagnosis of infective endocarditis (IE).</p><p><b>METHODS</b>A total of 205 patients with clinical diagnosis of IE admitted at West China Hospital of Sichuan University were included in this study. Among them, IE was pathologically confirmed in 97 patients. The sensitivities of both criteria for the diagnosis of IE were compared.</p><p><b>RESULTS</b>In 205 cases, the same microorganisms were detected twice in blood cultures in 13 cases (8.3%). Vegetations were detected by echocardiography in 183 patients (89.3%). In 97 cases with pathologically confirmed IE, the same microorganisms were detected twice in blood cultures in 6 cases (6.2%). Vegetations were detected by echocardiography in 89 patients (91.8%). IE diagnose was made in 44 (45.5%) and 86 (88.7%, P < 0.05 vs. Duke criteria) out of 97 pathologically confirmed IE patients by the Duke criteria and new national criteria, respectively. The specificities were 100% and 95.7% by Duke and new national criteria, respectively (P > 0.05).</p><p><b>CONCLUSION</b>With the addition of echocardiographic evidence of endocardial involvement and 2 minor criteria as definite diagnostic criteria, the sensitivity of the new national criteria is superior to that of the Duke criteria for diagnosing IE and the specificity for the diagnosis of IE between the two criteria is similar.</p>