Objective To study the effect of infrasound on expression of calmodulin-dependent protein kinase II (CaMKII) and tau pro-tein in hippocampus of rats. Methods Fifty-six male Sprague-Dawley rats were randomized into control group (n=8), 1-day group (n=8), 7-day group (n=8) and 14-day group (n=32), and the 14-day group was subgrouped as 1-hour, 6-hour, 24-hour, 48-hour subgroups, naming after the time after infrasound exposure, 8 in each subgroup. All the test groups were put in an infrasound field with 8 Hz, 130 dB for 2 hours daily, while the control group was put in the infrasound instrument without infrasound exposure for 2 hours daily. The expression of pT286-CaMKII and tau protein in hippocampus was detected with immunohistochemisty, Western blotting and enzyme-linked immunoabsor-bent assay. Results The expression of pT286-CaMKII was the most in 14-day group (F>14.912, P<0.001), as well as the expression of tau pro-tein (F>36.229, P<0.001), and secondary in 7-day group (P<0.05). For 14-day group, the expression of tau protein was the most in 1-hour and 6-hour subgroups, and dropped down in 24-hour subgroup, although more than that in the control group (P<0.05). Conclusion Exposure of 8 Hz, 130 dB infrasound may induce phosphorylation of CaMKII and tau protein, and the expression of tau protein in hippocampal cells in rat, which may disturb their learning and memory function.

Objective:To evaluate the reliability and validity of different quantitative methods based on CT images to evaluate the proportion of shoulder glenoid defect.Methods:Four shoulder joint specimens with no trauma, osteoarthritis or deformity were used, including 2 females and 2 males; the average age of death was 58±10 years old; all the specimens were prepared with a standard method with no bone defect occurring before preparation. A glenoid bone defect model was established with each specimen being cut into four defect gradient defects of approximately 8%, 16%, 24%, and 32% in proportion in sequence. A total of 16 samples were obtained. Physical photography and CT image reconstruction were performed on the 16 samples respectively. A total of 8 quantitative methods were used to quantify bone defects, which were surface area method, superimposed circle method, Barchilon method, Pico method, Shaha method, Griffith method, Sugaya method, and Giles method. Intraclass correlation (ICC) using a consistency model was used to evaluate reliability. Paired t-test was used to evaluate validity, with the physical measurement of the specimens using the surface area method as the reference standard. Result:The consistency ICC of each quantitative method was greater than 0.9, and all had high reliability. Combining the results of all bone defect gradients and imaging images, the surface area method had the best validity, which was 0.83%±0.75%; the Barchilon method came second, which was 0.91%±0.93%; the superimposed circle method and the Pico method had good validity, which were 0.99%±0.87% and 1.27%±1.09%, respectively; the Shaha method, the Griffith method, and the Sugaya method had poor validity, which were 6.11%±1.56%, 5.06%±1.35%, and 6.02%±1.61%, respectively; the Giles method had the worst validity, which was 8.40%±3.08%. Conclusion:In clinical practice, surface area method and superimposed circle method are the most reliable to quantify the proportion of bone defect if they can be performed. Otherwise, linear measurement of Barchilon method is the favored method while PICO method is the favored method for angle measurement.

Induced pluripotent stem cells(iPSCs)are obtained by introducing exogenous genes or adding chemicals to the culture medium to induce somatic cell differentiation.Similarly to embryonic stem cells,iPSCs have the ability to differentiate into all three embryonic cell lines.iPSCs can differentiate into cardiac muscle cells through two-dimensional differentiation methods such as monolayer cell culture and co-culture,or through embryoid body and scaffold-based three-dimensional differentiation methods.In addition,the process of iPSCs differentiation into cardiac muscle cells also requires activation or inhibition of specific signaling pathways,such as Wnt,BMP,Notch signaling pathways to mimic the development of the heart in vivo.In recent years,suspension culturing in bioreactors has been shown to produce large number of iPSCs derived cardiac muscle cells(iPSC-CMs).Before transplantation,it is necessary to purify iPSC-CMs through metabolic regulation or cell sorting to eliminate undifferentiated iPSCs,which may lead to teratoma formation.The transplantation methods for iPSC-CMs are mainly injection of cell suspension and transplantation of cell patches into the infarcted myocardium.Animal studies have shown that transplantation of iPSC-CMs into the infarcted myocardium can improve cardiac function.This article reviews the progress in preclinical studies on iPSC-CMs therapy for acute myocardial infarction and discusses the limitations and challenges of its clinical application to provide references for further clinical research and application.