镉对金鱼的急性毒性研究

以金鱼(Carassius auratus)为实验材料,采用改进的寇氏法(Karber method)进行了有毒物质重金属镉(Cadmium)对金鱼的急性毒性的研究.其目的在于评价水环境中镉对鱼类的影响,为制订水质标准提供参考数据.结果表明:在(18±2)℃下,镉对金鱼24、48、729、6 h的半致死浓度TLm(Median tolerance limits)分别为7.73、6.31、6.00、5.56 mg/L,其95%置信限分别为6.90~8.66、5.66~7.03、5.37~6.704、.92~6.29 mg/L,估算安全浓度为0.556 mg/L.     

ADP-ribosylhydrolases: from DNA damage repair to COVID-19

Adenosine diphosphate(ADP)-ribosylation is a unique post-translational modification that regulates many biological processes,such as DNA damage repair.During DNA repair,ADP-ribosylation needs to be reversed by ADP-ribosylhydrolases.A group of ADP-ribosylhydrolases have a catalytic domain,namely the macrodomain,which is conserved in evolution from prokaryotes to humans.Not all macrodomains remove ADP-ribosylation.One set of macrodomains loses enzymatic activity and only binds to ADP-ribose(ADPR).Here,we summarize the biological functions of these macrodomains in DNA damage repair and compare the structure of enzymatically active and inactive macrodomains.Moreover,small molecular inhibitors have been developed that target macrodomains to suppress DNA damage repair and tumor growth.Macrodomain proteins are also expressed in pathogens,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).However,these domains may not be directly involved in DNA damage repair in the hosts or pathogens.Instead,they play key roles in pathogen replication.Thus,by targeting macrodomains it may be possible to treat pathogen-induced diseases,such as coronavirus disease 2019(COVID-19).     

Availability and toxicity of Fe(II) and Fe(III) in Caco-2 cells

The objective of the present study was to compare the toxicity and availability of Fe(II) and Fe(III) to Caco-2 cells. Cellular damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(II) is significantly higher than that of the cells treated with Fe(III) (P<0.05). Fe(II) at a concentration >1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(III). LDH release investigation suggests that Fe(II) can reduce stability of the cell membrane. The activities of SOD and GPx of the cells treated with Fe(II) were higher than those of the cells treated with Fe(III), although both of them increased with raising iron supply levels. The results indicate that both Fe(II) and Fe(III) could reduce the cellular antioxidase gene expression at high levels. Project supported by the International Cooperative Project from the Ministry of Science and Technology of China (No. 2006DFA31030), the Bureau of Science and Technology of Zhejiang Province (No. 2006C32019) and HarvestPlus-China (No. 8022), and the Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT0536)     

针刺配合推拿治疗急性乳腺炎58例疗效观察

目的:观察针推治疗急性乳腺炎的疗效.方法:采用患野与远端辨证取穴相结合,运用针刺配合推拿进行治疗.结果:58例患者痊愈49例,显效7例,无效2例,总有效率96.5%.结论:针刺配合推拿治疗本病效果满意.     

两种常见农药对大弹涂鱼幼鱼的急性毒性研究

采用静态换水法检测了不同浓度下杀虫剂敌百虫和除草剂草甘膦对大弹涂鱼幼鱼的急性毒性．结果表明,大弹涂鱼幼鱼的死亡率随着农药浓度的升高而增加,并呈显著的相关关系;在水温24-28℃条件下,敌百虫对大弹涂鱼幼鱼48h和96h的半致死浓度（LC50）分别为1．25me4,和1．17mg/L,革甘膦对大弹涂鱼幼鱼48h和96h—LC50分别为335．47mg／L和308．55mg／L．显示了敌百虫和草甘膦对大弹涂鱼幼鱼具有一定潜在危害性．     

一次性耐力运动对大鼠间脑单胺类神经递质变化及代谢能力的影响

为运动性中枢疲劳的研究提供理论依据,建立持续游泳的动物模型,探讨一次性耐力运动对大鼠间脑单胺类神经递质变化及代谢能力的影响。结果为①3h游泳后即刻,间脑5-HT增加23.15%,至少可通过神经-内分泌调节、体温调节、情绪变化等因素影响机体的运动能力;②一次性耐力运动期间,间脑5-HT合成过程占优势,分解过程变化不明显,而恢复期分解代谢过程占优势;③一次性耐力运动可显著降低间脑DA水平,5-HT与DA比率亦显著性升高(P<0.05),20h恢复期间脑DA浓度增高,5-HT与DA比值降低(-27.51%)。     

SARS及其他几种冠状病毒密码子使用偏性的位点差异

分析了SARS冠状病毒以及其他5种冠状病毒基因编码起始区与终止区的密码子使用偏性.结果表明,冠状病毒基因组的稀有密码子倾向于出现在编码起始区和终止区附近.起始区的这种倾向性对冠状病毒基因的表达具有负性调控作用,可以用"稀有密码子调控假说"解释.终止区的这种倾向性表明,这些出现在终止区的稀有密码子对基因的表达也有负性调节作用.研究结果同时暗示了"稀有密码子调控假说"不仅适用于细菌,而且还适用于某些病毒基因组.     

地塞米松可以减少由重症急性胰腺炎引起的肾脏微血管内皮糖萼的损伤（英文）

目的:明确地塞米松可以减少重症急性胰腺炎(SAP)引起的肿瘤坏死因子(TNF-α)的释放,减轻TNF-α导致的肾脏血管内皮糖萼的降解,从而改善肾脏微循环和缓解肾损伤。创新点:本研究通过小鼠活体研究的方法,建立小鼠重症急性胰腺炎模型,并用地塞米松进行干预对照,采用透射电镜、激光多谱勒和酶联免疫的方法,检测了各组小鼠肾脏血管内皮糖萼的完整性、肾血流灌注和TNF-α表达情况,阐明了地塞米松对内皮糖萼的保护作用。方法:通过"胰管结扎+腹腔内雨蛙素注射"的方法建立SAP模型,分别留取各组小鼠的血液和组织标本,采用透射电镜观察内皮糖萼的损伤情况,用酶联免疫检测血清TNF-α和糖萼成份多配体聚糖的浓度,并用激光多谱勒检测活体小鼠肾脏的灌注,分析地塞米松对内皮糖萼的保护和改善肾脏灌注的作用。结论:SAP可以引起TNF-α的大量释放,并导致内皮糖萼的降解和肾脏灌注下降,而地塞米松可以减少TNF-α的释放,减轻糖萼的降解,改善肾脏血流灌注。     

Availability and toxicity of Fe(Ⅱ) and Fe(Ⅲ) in Caco-2 cells

The objective of the present study was to compare the toxicity and availability of Fe(Ⅱ) and Fe(Ⅲ) to Caco-2 cells.Cellular damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(Ⅱ) is significantly higher than that of the cells treated with Fe(Ⅲ) (P＜0.05). Fe(Ⅱ) at a concentration>1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(Ⅲ). LDH release investigation suggests that Fe(Ⅱ) can reduce stability of the cell membrane. The activities of SOD and GPx of the cells treated with Fe(Ⅱ) were higher than those of the cells treated with Fe(Ⅲ), although both of them increased with raising iron supply levels. The results indicate that both Fe(Ⅱ) and Fe(Ⅲ) could reduce the cellular antioxidase gene expression at high levels.