Effect of K^+ and the Interaction of Major Ions on Survival,Growth and ATP Enzyme Activity of Litopenaeus vannamei

[Objective] On the basis of previous researches, this experiment aimed to analyze the effect of K＊ and the interaction of K＋ , salinity （ s）, Ca2＋ , Mg2＋ on growth and adenosine triphosphatase （ATPase）, which was closely related to growth, of Litopenaeus vannamei. [Method] 5 -week Litopenaeus vannamei breeding experiment was performed according to L16（215） orthogonal experiment design. Then the effect of K＋ and the interaction of K＋ , salinity, Ca2＋ , Mg2＋ in water on survival, growth and ATP enzyme activity of Litopenaeus vannamei. [Result] K＋ had signifi- cant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannarnei. The highest survival rate was at K＂ of 150 rng/L. The fastest growth rate was at 50 mg/L, as well as the activities of Na＊ - K＋ -ATPase, Mg2＋ -ATPase, Ca＋ -ATPase. The interaction of salini- ty, Ca2＋ , Mg2＋ , K ＋ in water also had significant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannamei. [Conclusion] Among the horizontal combinations of factors in the experiment, the optimal combination for Litopenaeus vannamei survival rate was salinity of 15, K＋ of 150 mg/L, Ca2＋ of 100 mg/L, Mg2＋ of 300 mg/L, the optimal combination for growth rate was salinity of 15, K＋ of 50 mg/L, Ca2＋ 100 mg/L, Mg2＋ 100 mg/L, the optimal combination for Na＋ -K＊ -ATPase, Mg2＋ -ATPase, Ca2＋ -ATPase activity in Litopenaeus van- namei was salinity of 5, K＋ of 50 mg/L, Ca2＋ of 100 mg/L, Mg2＋ of 100 mg/L.

Study on Shigella Detection by ATP Bioluminescence Magnetic Enzyme Immunoassay

[Objective] The research aimed to establish a rapid detection method for Shigella. [Method] Combining immunomagnetic separation technology with ATP bioluminescence technology, a new kind of fast and accurate ATP bioluminescence magnetic enzyme immunoassay technique for Shigella was established. [Result] Using ATP bioluminescence magnetic enzyme immunoassay technique to detect standard solution for Shigella （ATCC 25931 ）, result showed that correlation coefficient between relative light intensity detected by instrument and bacteria concentration detec- ted by culture counting method was 0.981 1. Moreover, relation curve between relative light intensity and Shigella concentration was drawn. [ Conclusion] The method had a high detection speed and accuracy, and could be used for the rapid detection of pathogen in food and environment.

Aminooxyacetic acid improves learning and memory in a rat model of chronic alcoholism

Chronic alcoholism seriously damages the central nervous system and leads to impaired learning and memory.Cell damage in chronic alcoholism is strongly associated with elevated levels of hydrogen sulfide（H2S） and calcium ion overload.Aminooxyacetic acid is a cystathionine-β-synthase activity inhibitor that can reduce H2S formation in the brain.This study sought to observe the effect of aminooxyacetic acid on learning and memory in a chronic alcoholism rat model.Rats were randomly divided into three groups.Rats in the control group were given pure water for 28 days.Rats in the model group were given 6% alcohol for 28 days to establish an alcoholism rat model.Rats in the aminooxyacetic acid remedy group were also given 6% alcohol for 28 days and were also intraperitoneally injected daily with aminooxyacetic acid（5 mg/kg） from day 15 to day 28.Learning and memory was tested using the Morris water maze test.The ultrastructure of mitochondria in the hippocampus was observed by electron microscopy.H2S levels in the hippocampus were measured indirectly by spectrophotometry,and ATPase activity was measured using a commercial kit.The expression of myelin basic protein was determined by immunohistochemistry and western blotting.Compared with the control group,latency and swimming distance were prolonged in the navigation test on days 2,3,and 4 in the model group.In the spatial probe test on day 5,the number of platform crosses was reduced in the model group.Cristae cracks,swelling or deformation of mitochondria appeared in the hippocampus,the hippocampal H2S level was increased,the mitochondrial ATPase activity was decreased,and the expression of myelin basic protein in the hippocampus was down-regulated in the model group compared with the control group.All the above indexes were ameliorated in the aminooxyacetic acid remedy group compared with the model group.These findings indicate that aminooxyacetic acid can improve learning and memory in a chronic alcoholism rat model,which may be associated with reduction of hippocampal H2S level and mitochondrial ATPase activity,and up-regulation of myelin basic protein levels in the hippocampus.