ABSTRACT
Some enzymes belonging to the multicopper oxidase (MCO) family can degrade the hazardous biogenic amine (BA) present in food. However, the oxidation of MCO in the process of degrading BAs may reduce its activity and stability, resulting in decreased catalytic efficiency. In this work, an MCO from Lactobacillus fermentum (MCOF) was fused with a Bacillus subtilis catalase (CAT) using different strategies and the fusion enzymes were respectively expressed in Escherichia coli BL21(DE3). The tolerance of eight fused MCOFs to H2O2 increased by 51%-68%, and the stability of CAT&MCOF increased by 17%, compared to the wild type MCOF. Using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) as a substrate, the substrate affinity (Km), the catalytic efficiency (kcat/Km) and the molar specific activity of CAT&MCOF increased by 1.0-fold, 1.7-fold and 1.2-fold than those of MCOF, respectively. The stability of CAT&MCOF under acidic conditions (pH 2.5-4.5) and moderate temperatures (35-55 °C) also improved. Moreover, the degradation rates of putrescine, cadaverine and histamine catalyzed by CAT&MCOF reached 31.7%, 36.0% and 57.8%, respectively, which increased by 132.5%, 45.7% and 38.9% compared to that of MCOF. The improvement on the stability and catalytic efficiency of MCOF by fusion expression with CAT provides a good example for improving the applicability of enzymes through molecular modifications.
Subject(s)
Biogenic Amines , Cadaverine , Catalase/genetics , Escherichia coli/genetics , Hydrogen PeroxideABSTRACT
OBJECTIVE:To explore the effects of dobutamine on hemodynamics,tissue perfusion and respiratory function in patients with ARDS caused by septic shock. METHODS:Totally 26 patients with ARDS caused by septic shock were given Dobu-tamine hydrochloride injection 5 μg/(kg·min) by continuous pump for 20 min ,increasing by 5 μg/(kg·min) every 20 min to 15μg/(kg·min)for 6 h. Mean artery pressure(MAP)maintained at about 65 mmHg during continuous pump. Hemodynamic index-es [HR,MAP,cardiac output(CO),stroke volume(SV),total end diastolic volume(GEDV),intrathoracic blood volume index (ITBI),extravascular lung water index (ELWI),systemic vascular resistance index (SVRI)],tissue perfusion indexes (norepi-nephrine,urine volume,blood oxygen saturation,blood lactate)and ventilator parameter indexes(positive breathing pressure,min-ute ventilation volume,respiratory rate,peak inspiratory pressure and plateau pressure)of all patients were recorded before medica-tion,6,24,48 h after medication. RESULTS:There were no statistical significances in HR,MAP,GEDV,ITBI,blood oxygen saturation,blood lactate and respiratory rate before and after treatment (P>0.05). CO,SV,urine volume and minute ventilation volume of all patients 6,24,48 h after medication were significantly higher than before medication,and those indexes increased gradually as medication time. ELWI,SVRI,positive breathing pressure,peak inspiratory pressure and plateau pressure of all pa-tients after medication were significantly lower than before medication,and those indexes decreased gradually as medication time, with statistical significance(P0.05). CONCLUSIONS:The early application of dobutamine ELWI,tis-sue perfusion and respiratory function in patients with ARDS caused by septic shock,and can keep hemodynamics stable.
ABSTRACT
Objective To explore the effectiveness of insulin dialogue toolkit on psychological insulin resistance of type 2 diabetes. Methods A total of 134 type 2 diabetes with psychological insulin resistance were selected by the inclusion and exclusion criteria . The participates were randomly assigned to control group and intervention group by computer with 67 cases each. The control group was given conventional health education, the intervention group was given insulin dialogue toolkit instead of individual health education based on conventional health education. The intervention was lasted 2 weeks.The total score and each dimension score of my opinion of insulin and the blood glucose before and after intervention were observed. Results Before intervention, the total score in my opinion of insulin in intervention group and control group was (66.40±8.51), (66.91±7.27) scores, and there was no significant difference between two groups, P>0.05.After intervention, the total score in my opinion of insulin in intervention group and control group was(76.93±5.31), (71.09±7.77) scores, and there was significant difference between two groups, Z=-5.585, P0.05. Conclusions The insulin dialogue toolkit has an impact on psychological insulin resistance of type 2 diabetes. Insulin dialogue toolkit is a way to improve the diabetes′attitude of insulin, but the effect on blood sugar are not clarity.
ABSTRACT
Objective To explore the status and influencing factor of psychological insulin resis tance (PIR) of type 2 diabetes.Methods 137 in-patients with type 2 diabetes were investigated by selfdesigned questionnaire to get general data and Insulin Perceptions Questionnaire to get PIR data.Multiple linear regression were used to find influencing factor.Results 134 participates had PIR among the 137 in-patients.The older of age,using insulin for longer time and receiving insulin treatment positively had the higher scores of main questionnaire,then had less serious psychological insulin resistance.The duration of illness course,complications,work and using insulin for the first time or not had no relationship with their PIR.Conclusions The findings indicated that the type 2 diabetes using insulin have psychological in sulin resistance generally.Age,the time using insulin,accepting or receiving insulin positively are the independent factors of psychological insulin resistance