The changes of retinal nuclear DNA content in rats after death was detected and the relationship between degradation of retinal nuclear DNA and postmortem interval (PMI) was analyzed. Ninety healthy adult SD rats, female, weighing 250+/-10 g, were randomly divided into 15 groups. At 20 degrees C, the retinal cells were withdrawn every 2 h within 0 to 28 h after death and stained with Feulgen-Vans. Index of density (ID), integral absorbance (IA) and average absorbance (AA) in retinal nucleus were analyzed by image analysis system. And the obtained data were subjected to linear regression analysis by using SPSS12.0 software. The results showed that in retinal nucleus, AA and IA were gradually declined with the prolongation of PMI, while ID had an increased tendency. Within 28 h after PMI, the regression equations were as follows: Y(AA )=-0.009X(AA )+0.590 (R(2)=0.949), Y(IA )=-0.097X(IA )+18.903 (R(2)=0.968), Y(ID)=0.122X(ID)+2.246 (R(2)=0.951). It was concluded that retinal nuclear DNA after death in rats was degraded gradually and had a good correlation with PMI.

Objective To study the relationship between the mRNA degradation in the retinal cells of rat after death and postmortem interval(PMI) in order to provide a new methods of inferring PMI.Methods The level of ?-actin,Pgk1 and Rpl 4 mRNA in the retinal cell of rat were measured at different time(0,2,4,6,8,10, 12,14,16,18,20,22,24,26,28h)after death by compound fluorescence RT-PCR.The rats executed immediately were used as controls.Results Within 28h after death,the absorbance value of total RNA and the level of ?-actin,Pgk1 and Rpl 4 mRNA in the retinal cells decreased along with the prolongation of PMI.The equations of linear regression fitting the relationship between mRNA degradation and PMI were as follows:Y?-actin=-4436.205X?-actin+127581.7(r2=0.976),Ypgk1=-1993.884Xpgk1+57651.54(r2=0.973),YRpl 4=-1189.791XRpl 4+34533.46(r2=0.955).The return model had remarkable statistical significance(P

Forensic medical talents with creative ability should have ability to find.analyze and solve problems from complex cases.According to teaching practice on the basis of PBL this article illustrates application methods of PBL teaching characters in the training of forensic medical talents with creative ability.

Objective:To investigate the expression of SHIP1 in the patients with acute myeloid leukemia and its effect on the apoptosis of human leukemia cells.Methods:The expression of SHIP1 in the bone marrow of patients with acute myeloid leukemia was detected by Westem blot.U937 cells was transfected with SHIP1 expression vector (pEGFP-SHIP1 group) and empty vector control (pEGFP group) respectively,U937 cells without transfection were used as the control group.Flow cytometry was used to detect the apoptosis of the cells,the expression of SHIP1,Bcl-2,Bax,Akt,p-Akt were detected by western blot.Results:The expression of SHIP1 in the bone marrow of patients with acute myeloid leukemia was significantly lower than that of the normal human bone marrow SHIP 1 (P＜0.01).The SHIP1 and Bax expressions as well as the apoptotic rate ofpEGFP-SHIP1 group were significantly higher than those of the control group(P＜0.01),while the Bcl-2 and p-Akt expressions were significantly lower than those in the control group(P＜0.01).Conclusions:SH-P1 expression was down regulated in the bone marrow of patients with acute myeloid leukemia.SHIP1 could promote the apoptosis of human leukemia cells via Akt signaling pathway.

The changes of retinal nuclear DNA content in rats after death was detected and the relationship between degradation of retinal nuclear DNA and postmortem interval (PM1) was analyzed. Ninety healthy adult SD rats, female, weighing 250±10 g, were randomly divided into 15 groups. At 20 ℃, the retinal cells were withdrawn every 2 h within 0 to 28 h after death and stained with Feulgen-Vans. Index of density (ID), integral absorbance (IA) and average absorbance (AA) in retinal nucleus were analyzed by image analysis system. And the obtained data were subjected to linear regression analysis by using SPSS 12.0 software. The results showed that in retinal nucleus, AA and IA were gradually declined with the prolongation of PMI, while ID had an increased tendency. Within 28 h after PMI, the regression equations were as follows: YAA=-0.009XAA+0.590 (R2=0.949), YIA=-0.097XIA+18.903 (R2=0.968), YID=0.122XID+2.246 (R2=0.951). It was concluded that retinal nuclear DNA after death in rats was degraded gradually and had a good correlation with PMI.

Objective:To evaluate the anterior expansion of sacral foramen and decompression of sacral plexus via the lateral-rectus approach (LRA) in the surgical treatment of sacral fractures complicated with sacral plexus injury.Methods:From January 2013 to June 2018, 11 patients were treated at Department of Orthopaedics, The Third Hospital Affiliated to Southern Medical University for obsolete sacral fractures complicated with sacral plexus injury. They were 8 males and 3 females, aged from 17 to 54 years (average, 38 years). According to the Denis classification, all the sacral fractures belonged to Denis Zone Ⅱ. According to British Medical Research Council (BMRC) grading system, the nerve injury was complete damage in 2 cases and partial damage in 9. The mean time from injury to surgery was 6 months (range, from 0.7 to 12.0 months). After the sacroiliac joint was exposed via the LRA, the lumbosacral trunk was exposed and released between iliac vessels and the iliopsoas. Next, the S1 foramen was expanded and the S1 nerve root was released after separation of the median sacral artery and the internal iliac artery. Reduction and fixation of the sacroiliac joint was carried out for patients with unstable sacral fracture. X-ray and CT examinations of the pelvis were performed to evaluate fracture healing and neurological function recovery postoperatively.Results:Of this cohort of 11 cases, operation succeeded in 10 but failed in one whose sacral fracture was found to have completely healed with the S1 foramina totally occluded. The surgical time averaged 110 min (range, from 70 to 220 min) and the blood loss 1, 100 mL (range, from 450 to 2, 800 mL). Postoperative X-ray and CT examinations showed that the sacral foramens were expanded significantly without any complications. The follow-up time averaged 18 months (range, from 12 months to 4 years). By the BMRC grading system at the last follow-up, the neural function was completely recovered in 5 cases, partially recovered in 4 cases and not recovered in one.Conclusion:Significant anterior expansion of sacral foramen and decompression of sacral plexus via the LRA is a viable and effective alternative for treatment of sacral fractures complicated with sacral plexus injury.

Objective: To explore sarcoplasmic reticulum ryanodine receptor2 (RyR 2) expression and calcium releasing function in chronic heart failure (CHF) rabbits and to study the impact of long term valsartan treatment in relevant animals. Methods: HF model was established by volume overloading with pressure overloading in experimental rabbits. 27 rabbits were divided into 3 groups: Sham group, HF group and HF+valsartan group. n=9 in each group and the animals were treated for 7 weeks. Left ventricular structure, hemodynamic parameters, expression and functional changes of myocardiocyte sarcoplasmic reticulum RyR 2 were observed and compared among different groups. Results: Compared with Sham group, HF group had increased left ventricular mess index (LVMI), left ventricular end diastolic pressure (LVEDP) and decreased left ventricular shortening fraction, LVEF, all P<0.05. Compared with HF group, HF+valsartan group showed decreased LVMI, LVEDP and increased left ventricular shortening fraction, LVEF, all P<0.05. Sarcoplasmic reticulum RyR 2 expression and calcium releasing function were lower in HF group than Sham group, P<0.05; while they were both higher in HF+valsartan group than HF group, P<0.05. Conclusion: Long term application of valsartan could improve the cardiac function which might be related to increased myocardial sarcoplasmic reticulum RyR 2 expression and calcium releasing function in experimental CHF rabbits.

Objective: To explore the changes of protein expression and activity of calcium/calmodulin-dependent protein kinase-II (CaMK-II) in myocardium nucleus and sarcoplasmic reticulum in experimental rabbits with heart failure (HF).
Methods: A total of 16 rabbits were divided into 2 groups: Sham group and HF group, the HF model was established by volume overload plus pressure overload.n=8 in each group and all animals were treated for 7 weeks. Left ventricular structure, hemodynamic parameters and protein expression and activity of CaMK-II in myocardium nucleus and sarcoplasmic reticulum were examined and compared between 2 groups.
Results: Compared with Sham group, HF group presented increased left ventricular mass index (LVMI) (1.32 ± 0.06) g/kg vs (3.61 ± 0.09) g/kg, LVEDP (-1.50 ± 0.50) mmHg vs (23.00 ± 2.37) mmHg, allP<0.05; while decreased left ventricular shorten fraction (37.83 ± 3.58) % vs (17.38 ± 3.13) % and LVEF (71.92 ± 4.56) % vs (38.50 ± 6.07) %, allP<0.05. The protein expression and activity of CaMK-II were both higher in HF group than Sham group, allP<0.05.
Conclusion: Increased protein expression and activity of CaMK-II in myocardium nucleus and sarcoplasmic reticulum might be one of the mechanisms for HF occurrence in experimental rabbits.

Objective To investigate the effect of4-amino-2-trifluoromethyl-phenyl retinate(ATPR)on acute liver injury induced by lipopolysaccharide(LPS)in C57BL/6 mice and its related mechanism.Methods Fifteen 6-week-old male C57BL/6 strain mice were randomly divided into normal group,model group and ATPR group,with 5 mice in each group.Mice in the ATPR group were intraperitoneally injected with ATPR(15 mg/kg·d),and normal group and model group were given solvent.After continuous administration for one week,model group and ATPR group were intraperitoneally injected with LPS(6 mg/kg),and all mice were sacrificed 6 hours later.The contents of Alanine aminotransferase(ALT)and Aspartate aminotransferase(AST)in serum of mice were detec-ted.The mRNA levels of Interleukin-6(IL-6)and Tumor necrosis factor-alpha(TNF-α)were detected by qPCR.Hematoxylin-eosin(H&E)staining was used to observe the histopathological changes of liver in mice.The ultra-structural changes of mouse hepatocytes were observed by Transmission electron microscope(TEM).The expres-sion levels of mitochondrial damage-related proteins FUNDC1 and OPA1 and autophagy related proteins LC3B,P62,Beclin1 and ATG5 were detected by Western blot.Results Compared with the normal group,the content of ALT and AST in serum and the mRNA levels of IL-6 and TNF-α in liver tissue increased in the model group,and the changes were reversed in the ATPR group.H&E staining showed that the hepatic lobule structure was normal in the normal group,the hepatic cords were arranged radially,there was no hyperemia and inflammatory cell infiltra-tion,and the hepatocyte boundary was clear.In the model group,the intercellular space of liver was enlarged,the arrangement of hepatic cords was disordered,and inflammatory cells infiltrated.In the ATPR group,the intercellu-lar space of liver and the structure of hepatic cords were restored,and the inflammatory cell infiltration was less.TEM showed that the damaged mitochondria and lipid droplet accumulation in the hepatocytes of mice in the model group were compared with that in the normal group,and the morphology and quantity of mitochondria and lipid droplet in the hepatocytes of mice in the ATPR group tended to be normal.Western blot showed that compared with the normal group,the expression of FUNDC1 protein in the liver tissues of mice in the model group increased,the expression of OPA1 protein decreased,the ratio of LC3B Ⅱ to LC3B Ⅰ decreased,the expression of P62 protein in-creased,the expression of Beclin1 and ATG5 protein decreased,and the above changes were reversed in the ATPR group.Conclusion ATPR alleviates acute liver injury induced by lipopolysaccharide in mice by promoting autoph-agy.

As a threat to human health， steroid-induced osteonecrosis of femur head is a common refractory orthopedic disease mainly caused by glucocorticoids， with poor prognosis and unclear pathogenesis. Osteogenesis-associated signaling pathways play an important role in bone formation. Glucocorticoid-induced abnormal activation and transport of these signaling pathways lead to abnormal differentiation of bone marrow mesenchymal stem cells， dysfunction of bone metabolism， and osteogenesis disorders， which may be the main reasons for the occurrence and development of steroid-induced osteonecrosis of femur head. Bone formation and remodeling need the participation of bone marrow mesenchymal stem cells， which are stem cells characterized by continuous self-renewal and differentiation. The key to strengthening bone remodeling is to improve the osteogenic differentiation capacity， which is the key point to inhibit bone resorption and prevent bone marrow mesenchymal stem cells from differentiating into osteoclasts. Traditional Chinese medicine （TCM） has been used in the treatment of osteonecrosis in ancient times. It is recorded in the Treasury of Words on Materia Medica （《本草汇编》） that "The deficiency in the lower energizer cannot be tonified without Eucommiae Cortexz.The soreness in lower legs cannot be alleviated without Eucommiae Cortex...The pain in the waist and knee cannot be relieved without Eucommiae Cortex...Tonifying liver and invigorating kidney， Eucommiae Cortex is an essential medicine." This indicates that ancient physicians have already begun to use the liver-tonifying， kidney-invigorating， and sinew-bone-strengthening effects of Eucommiae Cortex for the treatment of osteonecrosis. As the national support for the development of TCM strengthens， increasing studies have been conducted on the TCM prevention and treatment of steroid-induced osteonecrosis of femur head. Studies have suggested that Chinese medicinal herbs can exert a positive effect on the differentiation of bone marrow mesenchymal stem cells by affecting targeted signaling molecules， and promote osteogenesis and bone defect repair， thus combating the occurrence and development of steroid-induced osteonecrosis of femur head. The regulation of osteogenic signaling pathway by Chinese medicines to prevent steroid-induced osteonecrosis of femoral head has become a hot research topic. This article reviews the studies about the prevention and treatment of steroid-induced osteonecrosis of femur head with the active components in Chinese medicinal herbs by regulating osteogenic signaling pathways. We then explore the mechanism of the active components in promoting the differentiation of bone marrow mesenchymal stem cells into osteoblasts and inhibiting their differentiation into osteoclasts to facilitate bone formation， aiming to provide a reference for the further study of treating steroid-induced osteonecrosis of femoral head with Chinese medicinal herbs.