The experiment was conducted by directed evolution strategy (error-prone PCR) to improve the activity of aflatoxin detoxifzyme with the high-throughput horse radish peroxidas and recessive brilliant green (HRP-RBG) screening system. We built up a mutant library to the order of 10(4). Two rounds of EP-PCR and HRP-RBG screening were used to obtain three optimum mutant strains A1773, A1476 and A2863. We found that mutant A1773 had upper temperature tolerance of 70 degrees C and that its enzyme activity was 6.5 times higher than that of the parent strain. Mutant strains A1476 worked well at pH 4.0 and its enzyme activity was 21 times higher than that of the parent strain. Mutant A2863 worked well at pH 4.0 and pH 7.5, and its enzyme activity was 12.6 times higher than that of the parent strain. With DNA sequencing we found that mutant A1773 revealed two amino acid substitutions, Glu127Lys and Gln613Arg. Mutant A1476 revealed four amino acid substitutions: Ser46Pro, Lys221Gln, Ile307Leu and Asn471lle. Mutant A2863 revealed four amino acid substitutions: Gly73Ser, Ile307Leu, Va1596Ala and Gln613Arg. The results provided a useful illustration for the deep understanding of the relationship between the function and structure of aflatoxin detoxifzyme.
Aflatoxin B1 ; antagonists & inhibitors ; chemistry ; Amino Acid Substitution ; Directed Molecular Evolution ; Enzyme Activation ; Enzyme Stability ; Multienzyme Complexes ; genetics ; metabolism ; Mutant Proteins ; genetics ; metabolism ; Point Mutation ; Polymerase Chain Reaction ; methods ; Protein Engineering

Objective To study the inducing factors and clinical characteristics of patients hospitalized for asthma exacerbation in China. Methods Patients hospitalized for asthma exacerbation at 29 hospitals in China were retrospectively recruited during 2013-2014. Results Clinical data of 3 240 asthmatic patients were collected and analyzed including 1 369(42.3%) males and 1 871(57.7%)females. The patients hospitalized for asthma exacerbation counted for 2.95% (6 375/215 955) of all patients hospitalized during the same period. The leading six inducing factors, in sequence, were acute upper respiratory tract infection[42.3%(1 370/3 240)],changes of weather[22.8%(738/3 240)],noxious gas[(4.3% (140/3 240), allergy challenges [3.5%(115/3 240)], strenuous exercise [1.8%(57/3 240)], and air pollution [1.5%(49/3 240)].In older patients,more exacerbations were induced by weather changes,yet less sensitive to allergy challenges. As to middle-aged patients, they were less sensitive to upper respiratory tract infections,however the difference was not statistically significant(P>0.05).In winter more asthma patients were induced by upper respiratory tract infections,while in autumn more patients were induced by weather changes,strenuous exercise and air pollution.In spring and summer more patients were induced by allergy challenges, but the differences failed to achieve statistical significance (P>0.05). In northern cities more patients were induced by upper respiratory infections, whereas in southern cities more by noxious gases. Allergy challenges and air pollution tended to affect more patients in northern cities,but the difference was of no significance (P>0.05). The differences of inducing factors among patients of different gender, with or without a smoking history, and with different exacerbation severity didn't show any statistical significance. The patients with severe and life-threatening exacerbations counted for 20.1%(652/3 240).The percentage of patients older than 60 years was higher in patients with severe or life-threatening exacerbations than in whose with mild or moderate exacerbations,so did the percentage of male patients,of patients with disease duration longer than 10 years, with smoking history, and with a history of hospitalization or emergency department visits due to asthma exacerbation during the last year.Conclusion The acute upper respiratory tract infection ranks top among all the inducing factors. Senility, male gender, long duration of disease, smoking history, and a history of frequent hospital visits might be the risk factors for severe or life-threatening asthma exacerbations.

OBJECTIVE:To determine quality indexes of Hejiang Dendrobium nobile at different harvesting time and months,and to provide scientific reference for reasonable harvesting period of Hejiang D.nobile.METHODS:The stem of annual,biennial and triennial D.nobile were collected.The drying rate,the contents of polysaccharides (colorimetry),dendrobine (GC) and total alkaloids (colorimetry),effective component total rate (dendrobine×drying rate) were measured.Biennial D.nobile were collected in autumn and winter (Oct.of the second year-Mar.of the third year,15th day a month) to determine drying rate,the contents of polysaccharides and dendrobine.RESULTS:The drying rate,the contents of polysaccharides and effective component total rate were higher than annual and triennial D.nobile.The content of total alkaloids and dendrobine were in descending order:annual D.nobile (0.52％,0.48％) ＞biennial D.nobile(0.48％,0.44％) ＞triennial D.nobile (0.32％,0.22％).From Oct.of the second year to Mar.of the third year,the drying rate of biennial D.nobile was increasing month by month;the contents of polysaccharides and dendrobine increased firstly and then decreased;the content of polysaccharide was the highest in Feb.(17.32％),and the content of dendrobine reached the highest level in Dec.(0.51％).CONCLUSIONS:The optimal harvesting period is biennial Hejiang D.nobile in Dec.and Jan.(third years before flowering),considering flowering characteristics,drying rate,the contents of polysaccharide and dendrobine.

Acute kidney injury (AKI) is a devastating complications of end-stage of liver disease (ESLD), seriously affecting the prognosis of patients. With the deepening understanding of the pathogenesis, the definition, staging, diagnosis and treatment of ESLD with AKI have been gradually optimized. This article reviews the evolution of definition, pathogenesis, diagnosis and treatment of ESLD with AKI, to provide reference for early recognition, precise diagnosis and standardized treatment of this condition.

PURPOSE: Details of patients hospitalized for asthma exacerbation in mainland China are lacking. To improve disease control and reduce economic burden, a large sample survey among this patient population is indispensable. This study aimed to investigate the clinical characteristics and outcomes of such patients.METHODS: A retrospective study was conducted on patients hospitalized for asthma exacerbation in 29 hospitals of 29 regions in mainland China during the period 2013 to 2014. Demographic features, pre-admission conditions, exacerbation details, and outcomes were summarized. Risk factors for exacerbation severity were analyzed.RESULTS: There were 3,240 asthmatic patients included in this study (57.7% females, 42.3% males). Only 28.0% used daily controller medications; 1,287 (39.7%) patients were not currently on inhaled corticosteroids. Acute upper airway infection was the most common trigger of exacerbation (42.3%). Patients with severe to life-threatening exacerbation tended to have a longer disease course, a smoking history, and had comorbidities such as hypertension, chronic obstructive pulmonary disease (COPD), and food allergy. The multivariate analysis showed that smoking history, comorbidities of hypertension, COPD, and food allergy were independent risk factors for more severe exacerbation. The number of patients hospitalized for asthma exacerbation varied with seasons, peaking in March and September. Eight patients died during the study period (mortality 0.25%).CONCLUSIONS: Despite enhanced education on asthma self-management in China during recent years, few patients were using daily controller medications before the onset of their exacerbation, indicating that more educational efforts and considerations are needed. The findings of this study may improve our understanding of hospital admission for asthma exacerbation in mainland China and provide evidence for decision-making.
Adrenal Cortex Hormones ; Asthma ; China ; Comorbidity ; Disease Progression ; Education ; Female ; Food Hypersensitivity ; Hospitalization ; Humans ; Hypertension ; Inpatients ; Medication Adherence ; Mortality ; Multivariate Analysis ; Pulmonary Disease, Chronic Obstructive ; Retrospective Studies ; Risk Factors ; Seasons ; Self Care ; Smoke ; Smoking

‍Liver failure is a serious clinical syndrome of liver disease with critical condition and high mortality， and besides liver transplantation， there is still a lack of satisfactory radical treatment methods. The pathogenesis of liver failure is complex and remains unclear， involving a variety of factors that affect the balance of hepatocyte necrosis and regeneration. This article summarizes autophagy as the key pathway for maintaining cell homeostasis and points out that autophagy plays an important protective role in the pathogenesis of liver failure by regulating NLRP3 inflammasome activation， reducing oxidative stress， and inhibiting cell apoptosis. Meanwhile， it is believed that the molecular signaling pathways targeting autophagy， such as exosomes and peroxisome proliferator－activated receptor α， participate in antagonizing the development and progression of liver failure and will become important ideas and directions for molecular targeted therapies for liver failure.

Objective: To understand the viral etiology of a clustered case of human infection outbreak in the middle school of Huai’an city. Methods: Nasopharyngeal swab samples from patients were collected and rapidly detected by Real-time RT-PCR and the target virus isolated in cells. Furthermore, HA1 segments of target virus were amplified by RT-PCR and sequenced. The genetic and phylogenetic analysis based on HA1 genes was computed. Results: Influenza A(H1N1)pdm09 viral nucleic acid in 11 nasopharyngeal swab samples from patients in the outbreak were positive. Compared to the vaccine strains A/California/07/2009, the Huai’an isolates, nucleotide identity was 97.7%-98.1%, and amino acid identity was 96.6%-97.4%. Phylogenetic analysis of HA1 segment sequences indicated that the Huai’an strains from the outbreak were related closely to the viruses isolated in the year of 2014. Sequence analysis indicated that the Huai’an isolates had no amino acid substitution in the receptor binding sites and glycosylation sites, while in the Ca1 of antigenic determinant of HA1 the Huai’an isolates had an amino acid substitution of S for T at 220. Conclusions The pathogen of the clustered case of human infection was Influenza A(H1N1)pdm09 virus. Though the Huai’an isolates had one animo acid substitution in the Ca1 of antigenic determinant, the antigenicity characteristic remained unchanged.

Objective:To evaluate the efficacy and safety of oral anisodine hydrobromide tablets in the treatment of nonarteritic anterior ischemic optic neuropathy (NAION).Methods:A multicenter nonrandomized controlled trial was conducted.A total of 282 acute NAION patients (282 eyes) were recruited from 16 hospitals in China from July 2020 to May 2021.Patients were divided into two groups according to treatment methods, which were control group (124 cases, 124 eyes) receiving regular treatment including citicoline sodium plus Ginkgo biloba leaf liquid extract or Ginkgo biloba leaf extract tablets plus mecobalamin, and experimental group (158 cases, 158 eyes) receiving treatment in control group plus oral anisodine hydrobromide tablets 1 mg, twice daily for 2 to 3 months.Best corrected visual acuity (BCVA), visual field index (VFI), peripapillary retinal nerve fiber layer (pRNFL) and radial peripapillary capillary vessel density (RPC) were assessed at 1, 2, 3, and 6 months after enrollment using the standard decimal visual acuity chart, 750i Humphery visual field analyzer, Cirrus HD-OCT 4000/Cirrus HD-OCT 5000, RTVue-XR optical coherence tomography respectively.The primary outcomes were BCVA and VFI, and the secondary outcomes were pRNFL, RPC, and the side effects during the follow-up.The study adhered to the Declaration of Helsinki.All patients were fully informed about the treatment and purpose of this study and voluntarily signed the informed consent form.The study protocol was approved by Chinese PLA General Hospital (No.S2020-021-01). Results:In all, 242 patients (242 eyes) completed the follow-up of BCVA, and 98 patients (98 eyes) completed the VFI follow-up.In terms of visual function, BCVA and VFI improved significantly over time in the two groups, and BCVA and VFI were better in experimental group than in control group at various follow-up time points (all at P<0.05). In terms of structure, pRNFL gradually decreased in both groups with the extension of treatment, and pRNFL was significanthy thinner in experimental group than in control group at various follow-up time points (all at P<0.05). There was no significant difference in RPC between the two groups at the last follow-up ( P>0.05). There were two cases with side effects and one case was discontinued due to side effects 25 days after enrollment. Conclusions:Oral anisodine hydrobromide can improve visual acuity and visual field in NAION and accelerate the regression of optic disc edema, with good safety.