Ricin is a plant toxin isolated from the seed of the castor plant(Ricinus communis). As a typical II ribosome inactivating protein,ricin consists of two polypeptide chains named ricin toxin A chain(RTA)and ricin toxin B chain(RTB),linked via a disulfide bridge. RTB binds to both glycopro?tein and glycolipid at the surface of the target cell and mediates ricin to be endocytosed and transported retro?gradely to the endoplasmic reticulum. After being reduced and retrotranslocated to the cytosol,RTA mediates its toxicity due to its activity of a RNA N- glycosidases. Aside from its main toxic effect of protein synthesis inhibition,ricin also displays other properties that contribute to its toxicity such as inducing apoptosis,cytokine secreting and peroxidation. Ricin is stable and can be easily isolated. It has many routes of intoxication with no specific antidotes. Due to its natural abundance,remarkable toxicity,and the potential to be used in biological warfare as well as terrorist attacks,ricin has been classified as a Category B biothreat agent. Here we reviewed its history as a biothreat agent,constitu?tion,intoxication mechanism,detection methods and the development of specific antitodes.

Objective:To analyze the immunogenicity of the extracellular region of Δ42PD1.Methods: Six fragments ofΔ42PD1 extracellular region-encoding sequence were amplified by PCR, and were cloned into pCTCON2 vector, a yeast surface displaying vector.Yeast cells were transfected with Δ42PD1 fragment-carrying plasmids, then yeast cells were spread on SDCAA plates.Single cell clones were selected and cultured in SGCAA media to induce expression of the target genes.Mouse anti-humanΔ42PD1 anti-serum were generated by immunization of BALB/c mice via intramuscular injection ofΔ42PD1-carrying plasmid plus in-situ electroporation.The binding of anti-serum with yeast cells surface-displaying Δ42PD1 fragments were analyzed using flowcytometry.Results:Nucleotide sequences analysis indicated that the amplified six fragments ofΔ42PD1 sequence length were 110 bp,and the isolated sequence ofΔ42PD1 fragments were 100%homology with PD1 gene previously registered in GenBank.Results from flowcytometry showed that among the six fragments of Δ42PD1 displaying on the surface of yeast cells,F3 and F2 profoundly boundΔ42PD1-specific polyclonal antibodies.Conclusion:F3 and F2 ofΔ42PD1 is an immunogenic dominant region,which pave the way for generation of Δ42PD1-specific monoclonal antibody and epitope mapping.

Public hospitals stand in need of strengthening cost control and improving operational efficiency to balance public welfare and economic benefits.Taking practice and exploration of ultrasound department as an exam-ple,it integrates the advantages of TDABC with cost management.Take the merits of time driver and activity driver,realizes direct cost accounting under the clinical pathway,strengthen capacity management capabilities un-der the integration of industry and finance,with a view to providing a powerful cost control tool for public hospitals to sensibly respond to pricing reform and reasonably make operational decisions.

Objective To systematically review the effects of probiotics on gastrointestinal function in critical patients with enteral nutrition.Methods We searched Pubmed, EMBASE, Web of Science, Cochrane, CNKI, WanFang Data, VIP and CBM to collect randomized controlled trials (RCTs) about probiotics improve gastrointestinal function and nutritional status in patients with enteral nutrition. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. Then, Meta-analysis was performed using Rev Man 5.3.Results A total of 11 RCTs involving 1042 patients were included. The results of meta-analysis showed that compared with the placebo/blank group, the probiotics groups had lower incidence rates of diarrhea, ventosity, astriction, emesis, reduce target feeding time, improved Alb levels and Hb levels, while there were no significant differences between two groups in time of nutritional support.Conclusions Current evidence indicates that, compared with enteral nutrition alone, probiotics combined with enteral nutrition can improve patients' gastrointestinal function and Alb,Hb levels, and reduce target feeding time.

Objective: To investigate the effect and mechanism of α-lipoic acid(ALA) on the formation of hypertrophic scar(HTS) in rabbit ears. Methods: Eighteen New Zealand white rabbits were randomly divided into normal group, model group and 4%ALA group. After 28 days of treatment, the changes of scar related indexes were evaluated by hematoxylin-eosin(HE) staining, Masson pine(Masson) staining and immunohistochemical staining, the changes of oxidative stress related indexes were evaluated, and the expression of antioxidant pathway related proteins was detected by Western blotting. Results: The color, texture and volume of scar in 4%ALA group were lighter and softer than those in model group. The results of HE, Masson staining and immunohistochemical staining showed that the number of fibrous cells and the degree of fibrosis in the 4%ALA group were less than those in the model group. In the 4%ALA group, the content of malondialdehyde(MDA) was lower than that of the model group(P<0.001), the content of hydroxyproline(Hyp) was lower than that of the model group(P<0.01), the level of glutathione(GSH) was higher than that of the model group(P<0.01), the activity of T-SOD was higher than that of the model group(P<0.001). Western blotting showed that the content of NRF2 and the expression level of downstream antioxidant proteins in the 4%ALA group were higher than those in the model group. Conclusion ALA up-regulates NRF2 signal pathway to reduce the level of oxidative stress in HTS and inhibit scar proliferation in rabbit ears.