Past,present and future of cyanide antagonism research:From the early remedies to the current therapies

This paper reviews milestones in antidotal therapies for cyanide(CN) spanning early remedies,current antidotal systems and research towards next generation therapies.CN has been a part of plant defense mechanisms for millions of years.It became industrially important in the nineteenth century with the advent of CN assisted gold mining and the use of CN as a pest control agent.The biochemical basis of CN poisoning was actively studied and key mechanisms were understood as early as 1929.These fundamental studies led to a variety of antidotes,including indirect CN binders that generate methemoglobin,direct CN binders such as hydroxocobalamin,and sulfur donors that convert CN to the less toxic thiocyanate.Research on blood gases at the end of the twentieth century shed new light on the role of nitric oxide(NO) in the body.The discovery of NO's ability to compete with CN for enzymatic binding sites provided a previously missed explanation for the rapid efficacy of NO generating antidotes such as the nitrites.Presently used CN therapies include:methemoglobin/NO generators(e.g.,sodium nitrite,amyl nitrite,and dimethyl aminophenol),sulfur donors(e.g.,sodium thiosulfate and glutathione),and direct binding agents [(e.g.,hydroxocobalamin and dicobalt salt of ethylenediaminetetraacetic acid(dicobalt edetate)].A strong effort is being made to explore novel antidotal systems and to formulate them for rapid administration at the point of intoxication in mass casualty scenarios.New antidotes,formulations,and delivery systems are enhancing bioavailability and efficacy and hold promise for a new generation of improved CN countermeasures.

Effects of EMS Treatments on Multiplication and Differentiation of Sugarcane Embryonic Cell Clusters

[ Objective] This study aimed to investigate the effects of EMS （ethyl methane sulfonate） treatments on multiplication and differentiation of sugarcane embryonic cell clusters. [ Method] Sugarcane variety Xintaitang 22 （ROC22） was used as the experimental material. After treated with different concentrations of EMS for different time, sugarcane embryonic cell clusters were collected for subculture, differentiation and rooting, to compare and analyze the correlation of differ- ent EMS treatments with the muhiplicafion and differentiation of sugarcane embryonic cell clusters. [ Result] Treating ROC22 embryonic cell clusters with 0. 10% -0.15% EMS for4-6 h led to the best results, which reached the level of semi-lethal dose. Sugarcane embryonic cell clusters treated with EMS were adopted for subculture; results indicated that browning rate of cell clusters was higher than that in control （CK） but embryonic structure proportion was lower than that in control ; in addition, multiplication multiple of sugarcane embryonic cell clusters was also lower than that in control. After treated with EMS, sugarcane em- bryonic cell clusters exhibited significantly lower bud differentiation rate and higher browning rate compared with control. Furthermore, treating sugarcane embryonic cell clusters with 0.15% EMS for 2 h was conducive to plantlet emergence and rooting of sugarcane embryonic cell clusters. [ Conclusion] This study provided the- oretical basis for effective mutagenesis of sugarcane using EMS.