Objective: To explore the impact of insulin resistance (IR) and adiponectin (APN) lacking on myocardial remodeling in experimental mice. Methods:16 normal C57 mice were divided into 2 groups: Control group and IR group; in addition, 16 APN gene knockout(APNKO) mice were divided into another 2 groups: APNKO group and APNKO+IR group.n=8 in each group. The mice in Control group and APNKO group were fed with normal diet, in IR group and APNKO+IR group were fed with high fat diet to create the IR model. All animals were treated for 12 weeks. Blood levels of total cholesterol(TC), triglycerides(TG),fasting plasma glucose(FPG) and fasting insulin(FINS) were examined; heart weight and left ventricular weight were measured; left ventricular myocardial morphological changes and the degree of ifbrosis were assessed by HE staining and Masson staining; protein expressions of myocardial matrix metalloproteinase-9 (MMP-9) and APN were detected by immunehistochemistry and Western blot analysis. Results: Compared with Control group, IR group, APNKO group and APNKO+IR group showed elevated blood levels of TC, TG, FPG and FINS; increased heart weight and left ventricular weight, allP<0.05; IR group, APNKO group and APNKO+IR group presented more myocardial hypertrophy, decreased protein expression of APN and increased protein expression of MMP-9, allP<0.05.Conclusion: IR and APN lacking could incur myocardial remodeling in experimental mice and they had synergistically facilitated effect.

Objective The study the effect on cardiac remodeling induced by low level adiponectin(APN)and insulin resistance(IR).Methods 16 wild-type C57 mice were randomly divided into control and IR groups.16 APN gene knockout mice were randomly divided into APNKO and APNKO+IR groups.The IR and APNKO+IR groups were a high-fat feed to induce insulin resistance.After 12 weeks,cholesterol(TC),triglycerides(TG),fasting plasma glucose(FPG), fasting insulin(FINS) were measured.HOMA-IR,HWI and LVWI were calculated.The left ventricular myocardial were examined by microscopy to observe the degree of myocardial fibrosis,and the protein expression of matrix metalloproteinase-9(MMP-9) and APN in myocardial were detected with western blot.ResultsLow level APN and IR increased heart weight, left ventricular weight, HWI, LVWI(P<0.05).There were interaction between IR and low level APN on the TC,TG, FPG, FINS, and the index related myocardial fibrosis(P<0.05), and they were positive effect.There was also interaction effect between IR and low level APN on myocardial APN expression, but it was the negative effects (P<0.05).Conclusions Both low level adiponectin and insulin resistance could lead to cardiac remodeling synergistically.

BACKGROUND:After the internal fixation of cannulated screws in femoral neck fractures,because the affected limb is often unable to bear weight in the short term and the implants with high stiffness have a stress shielding effect on the fracture end,it is easy to cause osteoporosis of the affected limb and changes in the biomechanical distribution of the proximal femur,the incidence of osteonecrosis of the femoral head is high after surgery.At present,few studies have been conducted on the biomechanical effects of osteoporosis at the proximal end of the femur occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws. OBJECTIVE:Using finite element analysis,to investigate the biomechanical effects of osteoporosis occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws and explore the role of biomechanical factors in osteonecrosis of the femoral head. METHODS:Based on the obtained CT scan data of the femur in a patient with a femoral neck fracture,a proximal femoral model for internal fixation for femoral neck fracture was established by Mimics 19.0,3-Matic,UG 11.0,Hypermesh 14.0,and Abaqus software.One finite element model of the proximal femur without osteoporosis and three finite element models of the proximal femur with osteoporosis were analyzed using Abaqus software.The stress,contact pressure,displacement peak and cloud map under different components of the four models were measured and analyzed,and the internal stress changes and distribution of the femoral head were compared and analyzed. RESULTS AND CONCLUSION:The stresses and contact pressures of the femoral head and lower anterior cannulated screws varied more with the degree of osteoporosis.The peak displacement of the four models increased slowly with the degree of osteoporosis.By one-way analysis of variance,there was no significant effect of the degree of osteoporosis on the peak stress,contact pressure,and displacement of the different components.The internal stress distribution of the femoral head changed with the degree of osteoporosis.Changes in the biomechanical environment of the proximal femur have an important impact on osteonecrosis of the femoral head.