Hyperhomocysteinemia inhibits tibial fracture healing in rats through PI3K/AKT signaling pathway.

To explore the influence of hyperhomocysteinemia (hHcys) on the tibial fracture healing in rats and its effect on the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway. A total of 36 Sprague-Dawley rats were randomly divided into sham group (n=12), tibial fracture group (n=12) and hHcys + fracture group (n=12). The rats in tibial fracture group underwent the tibial fracture surgery, while the model of tibial fracture and hHcys was established in hHcys + fracture group. The level of plasma homocysteine (Hcy) in each group was analyzed using the full-automatic biochemical analyzer, the fracture stress biomechanical measurement was performed, and the ultimate bending strength and torque were calculated. Moreover, the protein expressions of PI3K and phosphorylated (p)-AKT in tibial tissues were detected using western blotting, the messenger ribonucleic acid (mRNA) levels of Bcl-2 associated X protein (Bax) and caspase-3 were detected using quantitative polymerase chain reaction (qPCR), the apoptosis was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and the expressions of inflammatory factors were detected via immunohistochemistry. Compared with sham group, tibial fracture group and hHcys + fracture group had a significantly increased level of plasma Hcy, significantly decreased ultimate bending strength and torque, obviously decreased relative protein expressions of PI3K and p-AKT, increased mRNA levels of Bax and caspase-3 and an increased expression of pro-inflammatory factor tumor necrosis factor-α (TNF-α). Compared with tibial fracture group, hHcys + fracture group had a higher level of plasma Hcy, lower ultimate bending strength and torque, lower relative protein expressions of PI3K and p-AKT, higher mRNA levels of Bax and caspase-3, a higher apoptosis rate and a higher expression of TNF-α. hHcys blocks the downstream apoptotic signal transduction, promotes apoptosis and inflammatory response, and affects fracture healing through affecting the PI3K/AKT signaling pathway.

Multiple infection leads to backward bifurcation for a schistosomiasis model.

Based on years of experience in schistosomiasis prevention and treatment, one of the typical features of schistosomiasis is multiple infection of a human host by parasites, which may dramatically a ect the host's infectivity. In this paper we establish a schistosomiasis model that takes into consideration multiple infection by separating humans with single and multiple infectious. The disease free equilibrium is shown to be globally asymptotically stable under certain condition. The model analysis suggests that a backward bifurcation may occur if the transmission rate from multiple infected humans to snails is high. This conclusion has not been seen in previous models of schistosomiasis. Such backward bifurcation is not possible without considering multiple infections. This conclusion may provide a new threshold theory for the prevention and treatment of schistosomiasis. Furthermore, numerical simulations suggest that e ective treatment of humans with multiple infection is important to control schistosomiasis. Especially, prevention of multiple infection may be critical.

Parameter estimation of modeling schistosomiasis transmission for four provinces in China.

According to monitoring data of Anhui, Jiangxi, Hubei, Jiangsu Provinces, in this paper the transmission of schistosomiasis is studied based on Barbour's mathematical model. The values of the basic reproduction number and key parameters are obtained with two methods. The first method is to calculate directly by using parameter values in references. The second one is to estimate parameter values by the methods of noise measurement and data smoothing and then to obtain new values of basic reproduction number. Comparing these two methods, we found the second method is good to fit the data. This parameter values can be used as reference values in other provinces. Finally, some numerical simulations are carried out to discuss the development trend of prevalence of humans and snails in each province. It is found that schistosomiasis in four provinces is expected to be eliminated with the improvement or maintenance of the standards of prevention and control. Furthermore, the time needed is different in the different four provinces.

Epimedium protects steroid-induced avascular necrosis of femoral head in rats by inhibiting autophagy.

The effect of epimedium extracting solution on bone mineral density (BMD) of steroid-induced avascular necrosis of femoral head (SANFH) in rats was evaluated to further explore its function mechanism. Twenty-four Sprague-Dawley (SD) rats (male/female: 1/1) were randomly divided into three groups: the control (n=8), the glucocorticoid (n=8) and the epimedium (n=8) group. Rats in the glucocorticoid and the epimedium group were injected with prednisolone acetate injection in gluteal muscles with 15 mg/kg/day twice a week. The epimedium group was given 10 ml/kg ephedra extracting solution containing crude drug with the concentration of 1.5 g/ml daily by gavage. After 6 weeks, all the experimental rats were sacrificed and materials were extracted. The expression of autophagy-related proteins were detected by observing the bone of the femoral head. After comparison of the control group with the model group in BMD, it was found that there were significant differences (P<0.05). There were no significant differences between the control and the epimedium group (P>0.05). Neither between the glucocorticoid and the epimedium group (P<0.05). Epimedium extracting solution can significantly enhance the BMD of femoral heads, prevent osteoporosis and lead to collapse, increase the expression of apoptotic and protective proteins and reduce the expression of autophagy-related proteins, thus providing a preliminary theoretical study for the prevention and treatment of SANFH.