Objective:To investigate the protective effect of a composite hydrogel against hydrogen peroxide(H2O2)-induced oxidative stress injury in the cardiomyocytes,and to clarify its possible mechanism.Methods:The mice were subcutaneously injected with 100 μL of hydrogel.After normal feeding for 1,14,and 28 d,the mice were sacrificed.Tissue samples were collected and subjected to HE staining to observe the histocompatibity of the hydrogel.The primary cardiomyocytes isolated from 1-day-old SD rats were used to establish an oxidative stress injury model.The primary cardiomyocyties were divided into control,H2O2 and H2O2+Hydrogel groups.The primary cardiomyocytes in control group were cultured normally,the primary cardiomyocytes in H2O2 group were treated with 200 μmol·L-1 H2O2 for 24 h,and the primary cardiomyocytes in H2O2+Hydrogel group were incubated with 1 g·L-1 composite hydrogel and 200 μmol·L-1 H2O2 for 24 h.The viabilities of cardiomyocytes in various groups were assessed by cell counting kit-8(CCK-8)method.Dihydroethidium(DHE)and 2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA)staining were used to assess the reactive oxygen species(ROS)levels in the cells.The expressions of filamentous actin(F-actin)in the cells in various groups were detected by phalloidin fluorescence staining;the expressions of connexin 43(Cx43)and cardiac troponin T(cTnT)proteins in the cardiomyocytes in various groups were detected by immunofluorescence method.The apoptotic rates of cardiomyocytes in various groups were assessed with TUNEL staining method.The expression levels of apoptosis-related proteins B-cell lymphoma-2(Bcl-2)and Bcl-2-associated X protein(Bax)in the cardiomyocytes in various groups were assessed by Western blotting method.Results:The HE staining results showed that the inflammatory cells around the implanted hydrogel were less infiltrated,and the inflammatory reaction of subcutaneous implantation was less.Compared with control group,the viability of cardiomyocytes in H2O2 group was significantly decreased(P＜0.05),the level of ROS in the cells was increased(P＜0.05),the expression levels of Cx43,cTnT and F-actin proteins in the cells were decreased(P＜0.001),the apoptosis rate of cardiomyocytes were decreased(P＜0.01),the expression level of Bcl-2 protein in the cells was increased(P＜0.001),and the expression level of Bax protein was decreased(P＜0.01).Compared with H2O2 group,the viability of cardiomyocytes was significantly increased(P＜0.05),the level of ROS in the cells was decreased(P＜0.01),the expression levels of cTnT,Cx43 and F-actin proteins were increased(P＜0.01),the apoptotic rate of cardiomyocytes were significantly decreased(P＜0.001),the expression level of Bcl-2 protein in the cells were decreased(P＜0.01),and the expression level of Bax protein was increased(P＜0.01).Conclusion:Hydrogel may promote the expression of cardiomyocyte-related proteins by scavenging ROS in the environment and inhibit the cardiomyocyte apoptosis to achieve the protective effect on the cardiomyocytes under oxidative stress.

Objective To assess and synthesize the current evidence on association of rs6435862 and rs3768716 single-nucleotide polymorphisms (SNPs) of breast cancer susceptibility gene associated RING domain-1 (BARD1) gene and neuroblastoma (NB) susceptibility.Methods Five electronic databases including PubMed,Embase,Web of Science,CNKI and Wanfang were searched for potentially relevant studies on the association of BARD1 SNPs and NB from precious to May 10,2018.Main information of included studies was extracted after literature selection.Newcastle-Ottawa Scale (NOS) was employed for quality assessment.RevMan5.3 software was used to analyze the association of rs6435862 and rs3768716 SNPs and NB susceptibility under allelic model,homozygous model,heterozygous model,dominant model,as well as recessive model.Results Five case-control studies with 9 independent cohorts comprising 3597 NB patients and 10827 healthy controls were yielded for Meta-analysis.For NOS,each included study obtained no less than 6 stars and was labeled of high quality.The findings indicated that rs6435862 and rs3768716 polymorphisms had significant association with NB susceptibility under five genetic models (P＜0.05).Conclusion Rs6435862 and rs3768716 SNPs of BARD1 gene are significantly associated with NB;G-allele and GG-genotype carriers appear to have an increased risk of NB susceptibility.

AIM To study the chemical constituents from Securidaca inappendiculata Hassk..METHODS The dichloromethane and ethyl acetate fractions of S.inappendiculata 95％ ethanol extract were isolated and purified by silica,gel column and recrystallization,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Ten compounds were isolated and identified as 8-hydroxy-1,3,4-trimethoxyxanthone (1),1,2,7-trimethoxyxanth-one (2),4-hydroxy-3,5-dimethoxybenzaldehyde (3),sesamin (4),2-methoxy-3,4-methylenedioxybenzophenone (5),1,3,7-trihydroxy-4-methoxyxanthone (6),1,3,7-t-rihydroxy-2-methoxyxanthone (7),2-hydroxy-1,7-dimethoxyxanthone (8),3,8-dih-ydroxy-1,4-dimethoxyxanthone (9),oα-spinasterol (10).CONCLUSION Compound 1 is first found in the form of natural product,compounds 2-4 are isolated from genus Securidaca for the first time.

Objective To study the effect of electroencephalograph (EEG) bionic electrical stimulation at Wangu (GB12), Tianzhu (BL10), Neiguan (PC6) on cerebral blood flow and metabolism in patients with persistent vegetative state (PVS). Methods 60 patients with PVS were divided into observation group (n=30) and control group (n=30) according to the random number table. The control group received routine treatment, including basic management, hyperbaric oxygen therapy, awaking medicine, sensory stimulation, and so on; while the observation group received EEG bionic electrical stimulation at bilateral Tianzhu, Wangu (cheif electrodes) and Neiguan (auxiliary electrodes) in addition. They were treated for 30 days. They were assessed with the PVS score, and observed with transcranial Doppler ultrasound (TCD) and magnetic resonance spectroscopy (MRS) one day before and one day after treatment. Results The incidence of improvement was 86.67% in the observation group, more than 60.00% in the control group (P<0.05). The difference of blood flow velocity before and after treatment (ΔVm) of anterior-middle cerebral artery was more in the observation group than in the control group respectively (P< 0.001), as well as those of posterior cerebral-vertebral-basilar artery (P<0.01). The N-acetyl aspartic acid/creatine (NAA/Cr) increased more in the observation group than in the control group respectively (P<0.01), and the choline/creatine (Cho/Cr) decreased more (P<0.01), after treatment. Conclusion EEG bionic electrical stimulation can improve the cerebral circulation and metabolism in patients with PVS, which may associate with the wake promoting.

The thought mainstream of contemporary medical students is steady and healthy,positive and upward,but there still exists some morality-degradating phenomena,such as indifferent service,weaking responsibility,etc.Therefore,the introduction course of Mao Zedong thought should bring its educational fuction into full use,publicize the revolutionary humanitarianism,and cultivate medical students'noble moral realm to prodce qualified constructor and successor for the socialist hearth care industry.