Catch-up growth,a phenomenon that occurs after a short time growth-inhibiting condition,has been proved to be strongly associated with insulin resistance.But the mechanism of insulin resistance in the process of catch-up growth is not clear.

ObjectiveTo observe the effect of resveratrol on the oxidative stress and antioxidant levels of different mitochondrial subpopulations in the skeletal muscle and insulin sensitivity of rats fed with high-fat diet.MethodsMale SD rats,aged 8 weeks,were divided into normal chow (NC) group,high-fat diet(HF) group,high-fat diet plus resveratrol ( HFR ) group.After intervention for 8 weeks,the impacts of resveratrol on oxidative stress levels and antioxidant enzymes activities in subsarcolemmal ( SS ) and intermyofibrillar ( IMF ) mitochondria from skeletal muscle as well as general and skeletal mascle insulin sensitivity were assessed.ResultsCompared with NC group, insulin sensitivity was significantly reduced while reactiveoxygenspecies (ROS)and malondialdehyde(MDA) levels in SS and IMF mitochondria increased in HF group ( all P＜0.01 ).In addition,antioxidant enzyme activities were significantly decreased in SS mitochondrial and increased in IMF mitochondrial ( both P ＜ 0.05 ).Compared with HF group,the insulin sensitivity in HFR group was significantly improved.Moreover,the activities of antioxidant enzymes in SS and IMF mitochondrial were increased,and the oxidative stress levels returned to normal ( P ＜ 0.05 ).ConclusionResveratrol notably improves the oxidative stress of different skeletal muscle mitochondrial subpopulations and insulin resistance in rats fed with high-fat diet.

Objective To investigate the phenotypes and percentages of B 10 cells in different tis-sues from wild-type mice and to identify their biological functions .Methods The percentages of B10 cells derived from different tissues of mice and their responses to lipopolysaccharide ( LPS) stimulation were ana-lyzed by flow cytometry .Magnetic-activated cell sorting ( MACS ) and fluorescence-activated cell sorting (FACS) were used to purify B10 cells, CD4+CD25-T cells and Treg cells.CD4+CD25-T cells and Treg cells labeled by CFSE were co-cultured with or without B10 cells, and then their proliferation were evaluated after 72 h.Results (1) A subset of CD19+CD5+CD1dhigh regulatory B cells was identified in spleen , pe-ripheral blood and lymph nodes from wild-type mice , of which the highest frequency was detected in spleen (3.95%±0.79%, P<0.05).The isolated B cells from different tissues were stimulated by LPS , PMA, ionomycin and monensin (L+PIM) in vitro to express IL-10.Among them, splenic CD19+IL-10+B cells showed the highest expression of IL-10 (P<0.05).(2) Prolonged LPS stimulation (48 h) to CD5+CD1dhigh B cells enhanced the expressions of IL-10 (P<0.01).(3) CD19+CD5+CD1dhigh B cells inhibited the prolif-eration of CD4+CD25-T cells in vitro in a dose-dependent manner (P<0.01), but increased the secretion of IL-10 by CD4+T cells (P<0.01) and the proliferation of Treg cells in vitro (P<0.01).Conclusion Com-pared with other tissues , the percentage of B10 cell subset in spleen is the highest in wild-type mouse , and B10 cells subset can be activated through Toll-like receptor ( TLR ) signaling pathway .The responses of CD4+CD25-T cells and Treg cells in co-culture with B10 cells are regulated by B 10 cell subset through an increased IL-10 production .B10 cells might be a useful cell population for the treatment of inflammatory au-toimmune diseases.

ObjectiveTo investigate the effects of adult catch-up growth on insulin sensitivity and stress in rats, as well as the probable mechanism of insulin resistance. MethodsMale Sprague-Dawley rats were divided into 6 groups:caloric restriction group ( R4, caloric restriction for 4 weeks) and normal controls for 4 weeks ( NC4 ) ; catchup growth group refed with normal chow( RN4, refeeding for 4 weeks after caloric restriction for 4 weeks), catch-up growth group refed with high-fat diet( RH4, refeeding for 4 weeks after caloric restriction for 4 weeks ), normal chow (NC8) or high-fat diet( HF8 ) controls for 8 weeks. The animal model of catch-up growth was devoloped by way of refeeding after caloric restriction as scheduled. The glucose infusion rate( GIR ), 2-deoxyglucose uptake and insulinsitmulated insulin signaling in skeletal muscle during hyperinsulinemic-euglycemic clamp, plasma corticosterone, and 11β-hydroxysteroid dehydrogenase type 1 ( 11β-HSD1 ) mRNA expression level in skeletal muscle were determined.ResultsAfter caloric restriction for 4 weeks, plasma corticosterone and 1 1 β-HSD1 mRNA expression in skeletal muscle were significantly higher in R4 group compared with NC4 group( both P＜0. 05 ), but there were no differences in 2-deoxyglucose uptake and Ser473 phosphorylation of Akt in skeletal muscle between two groups. The plasma corticosterone and 11β-HSD1 mRNA expression in skeletal muscle in RN4 group were significantly higher than those in NC8 group, and were higher in RH4 group than those in NC8 and HF8 groups; while the 2-deoxyglucose uptake and insulin-stimulated Ser473 phosphorylation of Akt in skeletal muscle during the clamp in RN4 were remarkably lower than those in NC8 group, and were lower in RH4 than those in NC8, HF8, and RN4 groups (all P ＜ 0. 05 ).ConctusionsCatch-up growth rats refed with normal chow or high-fat diet are characterized by significant insulin resistance and stress in the whole body and skeletal muscle. These changes are more evident in catch-up growth rats refed with high-fat diet. The interaction of increased stress and diet might be of utmost importance in the etiology of insulin resistance in catch-up growth animals.

dation, transiently inercasod food efficiency,and a faster growth rate of visceral adipose tissue versus body weight after nutritional rehabilitation. These findings are consistent with the characteristics of human catch-up growth.

Homocysteine is a risk factor for ischemic stroke.The association between homocysteine and ischemic stroke has been becoming a hot spot of research all over the world,but has not yet got a consistent result up to now.In this article,we reviewed the pathogenic mechanism,intervention,new treatment strategies,and summarized the current progress of the association of homocysteine with ischemic stroke.

Objective: The objective of this study was to verify the lipid-lowering effect of Juhe Fang extract (JHFE) and to determine its characteristic chemical profile in vitro and in vivo. Methods: A hyperlipidemia model was established by feeding mice a high-fat diet (HFD). After treatment for 30 days, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were measured with an automatic biochemistry analyzer. The components from JHFE obtained from in vivo and in vitro experiments were investigated using an UPLC-Q Exactive-Orbitrap MS/MS. Results: The TC, TG, and LDL-C in the serum significantly decreased and the HDL-C significantly increased after JHFE treatment. A total of 95 compounds from JHEF including 15 phenolic acids (PA), 4 phenyl-ethanoid glycosides (PG), 24 flavonoids (F), 14 triterpenoids (T), 10 diterpenoid glycosides (D), 18 alka-loids (A) and 10 others (O) were identified. Trigonelline was discovered for the first time in a herbal medicine of Juhe Fang. Furthermore, 68 compounds were identified in vivo including 28 prototype compounds and 40 metabolites. The metabolic characteristics of these components were revealed including identification of new metabolites of 4-hydroxyphenyl ethyl-8-O-[α-L- arabinopyranosyl-(1→6)]-β-D-glucopyranoside (PEG) and lirinidine. A total of 43 components from JHFE were absorbed and/or metabolized. The contribution rate of each type of chemical component from JHFE to its lipid-lowering effect from high to low were A, F, PG, PA, D and T. Conclusion: The results of this study showed that JHFE demonstrated a significant lipid-lowering effect in a high-fat diet (HFD)-induced hyperlipidemia mouse model. Specific types of PA, PG, F, D, T and A formed the pharmaceutical architecture of the lipid-lowering effect of JHFE. This study should prove useful for clarifying the components responsible for the lipid-lowering effect of JHFE and provide a basis for precision quality control research.

BACKGROUND:The traditional view is that proximal fibular fractures do not require fixation.Others and our research suggest that the proximal fibular structure plays an important role in the stability of the posterolateral structure of the knee joint,and its mechanism of action is worth studying. OBJECTIVE:To investigate the biomechanical effects of proximal fibular fractures on various structures of the knee joint in an extended state. METHODS:Finite element method was used to conduct simulated biomechanical experiments.A healthy young male volunteer was selected to establish a finite element model of the knee joint in an extended state using MRI and CT image data,and four proximal fibular shapes were simulated(Model A:intact,Model B:1 cm fracture below the fibular head,Model C:1 cm tip defect fracture from the proximal end of the fibula to the distal end,and Model D:2 cm bone defect from the proximal end of the fibula).A longitudinal concentrated load of 1 500 N was applied to the femoral shaft to compare and analyze the distribution and changing trend of the maximum equivalent stress and maximum first principal stress of each structure of the knee joint in an extended state under four working conditions. RESULTS AND CONCLUSION:(1)In Model A,the maximum equivalent stress in the tibial cartilage and lateral compartment of the meniscus was greater than that in the medial compartment,while the maximum first principal stress in the tibial plateau and medial compartment of the meniscus was greater than that in the lateral compartment.The maximum equivalent stress of the medial condyle of the femoral cartilage was greater than that of the lateral condyle,and the maximum first principal stress of the medial condyle of the femoral cartilage was greater than that of the medial condyle.(2)Compared to Model A,there was no significant difference in the magnitude and distribution of the maximum equivalent stress and maximum first principal stress in the cartilage and meniscus of Model C.(3)Compared to Model A,the maximum equivalent stress increase amplitude of Model B was in the order of medial tibial cartilage(14.9％),medial condyle of femoral cartilage(13.6％),and medial meniscus(6.6％).The maximum first principal stress increase amplitude was the medial meniscus(11.06％),the medial tibial cartilage(8.65％),and the medial condyle of the femoral cartilage(7.46％).The maximum equivalent stress increase amplitude of the ligament was as follows:popliteal arch ligament(33.2％)>anterior cruciate ligament(21.3％)>fibular collateral ligament(17％)>posterior cruciate ligament(14.3％)>anterior lateral collateral ligament(13.2％)>medial collateral ligament(10.1％).(4)Compared to Model A,the maximum equivalent stress increasing trend of Model D followed the medial tibial cartilage(19.5％),femoral cartilage medial condyle(17.9％),and medial meniscus(9.9％).The maximum first principal stress in sequence was the medial meniscus(14.04％),the medial tibial cartilage(13.03％),and the medial condyle of the femoral cartilage(11.37％).The increasing trend of maximum equivalent stress in ligaments was as follows:anterior cruciate ligament(25.2％)>posterior cruciate ligament(18.9％)>medial collateral ligament(18.5％)>anterior lateral collateral ligament(12.7％).(5)It is suggested that when the knee joint is extended,a 1 cm fracture below the fibular head and a 2 cm fibular tip bone defect have a significant impact on the structure of the medial ventricular cartilage,anterior cruciate ligament,and posterior lateral ligament complex.

Objective To investigate the effects of three-dimensional(3D)screws and circular plates on the biomechanical stability of Sanders ABⅢ calcaneal fractures.Methods Calcaneal computed tomography(CT)and magnetic resonance imaging(MRI)data from a 26-year-old volunteer were collected to establish a 3D finite element model of Sanders ⅢAB calcaneal fracture fixed with 3D screws and circular plates.A longitudinal load of 700 N was applied to compare the variations in the stress,displacement of the bone block,and internal fixation in the different models.Results Under 700 N longitudinal loads,the maximum displacement of the bone block and the maximum stress of the bone block and internal fixation were concentrated at the intersection of the posterior talar articular plane internal fixation and fracture line.The overall displacements of the bone blocks in the 3D screw and circular plate models were similar.Compared with the circular plate model,the maximum and average stresses of the bone block and internal fixation in the 3D screw model were lower,and the displacement and stress changes of the 3D screw model were closer to those of the complete calcaneal bone model.Conclusions In the fixation of Sanders ⅢAB calcaneal fractures,both 3D screw and circular plate fixation method can provide good stability.The biomechanical properties of the 3D screws were better than those of the circular plates,which is consistent with the biomechanical characteristics.

BACKGROUND:Satisfactory clinical results have been achieved in the treatment of Sanders Ⅲ calcaneal fractures by percutaneous compression fixation with three-dimensional frame screws.However,whether the stability of minimally invasive plate internal fixation can be achieved in terms of biomechanics,and the advantages and disadvantages after comparison are still unknown. OBJECTIVE:To investigate the fixation effect of different internal fixation devices on Sanders Ⅲ calcaneal fractures by finite element analysis. METHODS:A finite element model of Sanders Ⅲ calcaneal fracture was made based on CT data of a 26-year-old healthy male volunteer.The calcaneal fracture models were fixed by minimally invasive three-dimensional frame screws and minimally invasive Y-plate.The longitudinal loads of 350 and 700 N were applied respectively.The displacement and stress distribution of the two models were analyzed,and the stability of each model was compared. RESULTS AND CONCLUSION:(1)The peak stress of bone block and implant in the minimally invasive three-dimensional frame screw model was significantly lower than that in the minimally invasive minimally invasive plate model.The average stress of bone block and implant in the three-dimensional frame screw model was also significantly lower than that in the minimally invasive plate model.(2)The maximum displacement of the two models was located at the medial side of the articular surface of the posterior talus,and the maximum displacement of the three-dimensional frame screw model was smaller than that of the minimally invasive plate model.(3)The longitudinal displacement between the anterior fragment and the medial fragment of the minimally invasive plate model was smaller,and the transverse and vertical displacement between the medial fragment and the middle fragment of the three-dimensional group screw model was smaller.(4)It is concluded that both of the two internal fixation models can provide satisfactory fixation effect.The three-dimensional frame screw model can provide better transverse and vertical stability with more uniform stress distribution and smaller comprehensive displacement of bone fragments,while the minimally invasive plate has more advantages in maintaining longitudinal stability.