The synergistic effect of trypsin with antioxidant enzymes can improve the storage quality of H. undatus. Transcriptomic analysis and PPI network indicated that CAT is the key one among the enzymes of the complicated antioxidant system.

Trypsin is an endogenous enzyme that is generally used as a proteinase. Intriguingly, we found that trypsin had superoxide scavenging activity. In the current study, our results showed that trypsin scavenges superoxide in either intracorporal or extracorporal systems. In the light of the porcupine plots of trypsin compounds generated by ProDy, the copper ion binds to trypsin and accelerates the superoxide scavenging activity of trypsin by increasing the stability of the structure. Furthermore, the data on the age-related parameters showed that the aging of mice could be slowed by trypsin, at least in part, due to its superoxide scavenging activity. These results suggested that trypsin is an effective superoxide scavenger and has potential as a novel agent to promote health and improve aging-associated pathologies.

Ultrastructural alteration and hydrogen peroxide localization were examined in Xanthomonas campestris pv. phaseoli during rifampicin effect using transmission electron microscopy. Bacterial cells were treated with rifampicin and then were examined by electron microscopy to observe the changes of ultrastructure or hydrogen peroxide accumulation in living cells that took place before lysis. Intriguingly, rifampicin treatment led to presence of an additional location of hydrogen peroxide accumulation within the cells. There was an association between the frequency and size of the additional location of hydrogen peroxide accumulation and the concentration of rifampicin. Furthermore, an additional ultrastructure, mesosomes, was also present in cells during rifampicin effect. The frequency and size of mesosome increased with the increasing concentration of rifampicin. Result of multiple linear regression showed that the size of mesosome plays as a key factor in the quantity of excess hydrogen peroxide accumulation in cells during rifampicin effect. Linear correlation was confirmed between quantity of excess hydrogen peroxide accumulation and the size of mesosome in cells during rifampicin effect. This finding intensely indicated that mesosomes are just the additional location of hydrogen peroxide accumulation in cells under cellular injury caused by rifampicin treatment. The mesosome formation is always accompanied by excess hydrogen peroxide accumulation in X. campestris pv. phaseoli during rifampicin effect.

Production and localization of endogenous hydrogen peroxide (H2O2) were investigated in strains of Xanthomonas by histochemical analysis under electron microscopy. Even though the levels of endogenous H2O2 production were different among various strains, the produced H2O2 was localized in the cell wall of all Xanthomonas strains tested. The impairment of the level of endogenous H2O2 accumulation resulted in a significantly decreased growth rate of bacteria, regardless if the difference of the H2O2 level is originally present between wild type strains or caused by mutation of the ahpC gene of Xanthomonas. The endogenous accumulation of H2O2 positively correlates with the cell division. Interestingly, the accumulated H2O2 was also localized in the mesosome-like structure and nucleoids during the cell division cycle. Furthermore, results revealed quantitative and dimensional changes of H2O2 accumulation in the two additional locations. These findings indicated that the additional locations of the accumulated H2O2 were closely associated with the process of cell division. Together, these results suggest that the endogenous H2O2 production plays an important role in cell proliferation of Xanthomonas.

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It has been revealed by us that superoxide scavenging is a new activity of trypsin. In this study, the synergistic mechanisms of trypsin and superoxide dismutases (SODs) were evaluated in Hylocereus undatus (pitaya). Trypsin significantly improved the storage quality of H. undatus, including weight loss impediment and decrease of cellular injury. The regulatory mechanisms of 16 SOD genes by trypsin were revealed using transcriptomic analysis on H. undatus. Results revealed that important physiological metabolisms, such as antioxidant activities or metal ion transport were induced, and defense responses were inhibited by trypsin. Furthermore, the results of protein-protein interaction (PPI) networks showed that besides the entire ROS network, the tiny SODs sub-network was also a scale-free network. Cu/Zn SODs acted as the hub that SODs synergized with trypsin during the storage of H. undatus.Trypsin is a widely used protease. It has been confirmed that trypsin significantly impacts on the free radical scavenging activities of flavonoids [8]. Our previous results also showed that trypsin scavenges superoxide anions (O 2 • − ) and protects cells [9].In the area of phytopathology, transcriptomic analysis has been successful used on lots of plants [10][11][12][13]. However, few of transcriptomic works have been focused on the preservation of fruits. The mechanisms of betalain biosynthesis have been investigated in H. undatus [2], and the concision analysis of antioxidant system induced by trypsin has also been investigated in our previous paper [14]. Considering the superoxide scavenging activity of trypsin, the function and synergistic mechanisms of trypsin with SODs impact on the quality of H. undatus during storage is an interesting work. The mechanisms of postharvest quality of fruits still need more works.Protein-protein interaction (PPI) networks analyses help us to figure out the regulatory mechanisms of proteins [15]. Plugins of Cytoscape, including NetworkAnalyzer, Molecular Complex Detection (MCODE), and cytoHubba, could score and rank the nodes or obtain clusters in the PPI network [16].In the current work, the regulatory mechanisms of trypsin on the H. undatus by cooperating with SODs were investigated. The changes in expression of SODs of H. undatus peels were analyzed. Analyses of gene ontology (GO) and KEGG enrichment of ROS or SOD related genes were performed, and the PPI network of ROS related genes and sub-network of SODs and their first neighbors were constructed. The hub genes of SODs regulated by trypsin during storage were further screened by cytoHubba and MCODE of cytoscape.

Summary What is known and objective Like many countries in the world, China is also facing growing drug expenditures year by year. In particular, the rising cost of prescription drugs has been one of the critical factors leading to the serious burden on health insurance programs. The high cost of prescription drugs not only threatens the health budget but also limits the nation's investment in other public sectors. China implemented the National Centralized Drug Procurement (NCDP) policy, also known as the "4 + 7" policy, in tertiary hospitals in various provinces and cities across the country on 18 December 2019, aiming to lessen personal and national health insurance burdens by reducing drug procurement prices. The aim of this study is to explore the impact of the implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments and on national health insurance expenditures. Methods This study adopts interrupted time series (ITS) to evaluate the impact of China's implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments in a tertiary hospital. The NCDP policy was officially implemented on 18 December 2019. A segmented regression model is utilized to analyse the average monthly drug expenditures of patients treated in outpatient and emergency departments from January 2018 to June 2021, including the average monthly per‐visit drug expenditures of all patients and the average monthly per‐visit drug expenditures of patients who paid for drugs with health insurance and those who did not use health insurance. Results After the implementation of the NCDP policy, the overall average monthly per‐visit drug expenditures of patients treated in outpatient and emergency departments were immediately reduced by 233.954 CNY (p < 0.01). Compared with the continued downward trend for drug expenditures before the implementation of the NCDP policy, the long‐term trend after policy implementation was not obvious (p = 0.051973>0.05). Similarly, the average monthly per‐visit drug expenditures of patients treated in outpatient and emergency departments who use health insurance to procure drugs also immediately decreased by 505.287 CNY (p < 0.01), but the long‐term trends before (p = 0.469>0.05) and after policy implementation (p = 0.51>0.05) did not exhibit obvious change. For the average monthly per‐visit drug expenditures of patients treated in outpatient and emergency departments who did not use health insurance, the implementation of the NCDP policy did not produce an immediate reduction in drug expenditures (p = 0.3603>0.05). Although the average monthly per‐visit drug expenditures decreased by 9.078 CNY (p < 0.01) before policy implementation, this trend ended after the policy was implemented (p = 0.0735>0.05), and no other changes were triggered. What is new and conclusion This study reviews the data for a period of time before and after the implementation of the NCDP policy. The policy is shown to significantly dec...

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