[Effect of China Children's Asthma Action Plan on exercise in school-age children with bronchial asthma].

Objective: To investigate the effect of China Children's Asthma Action Plan (CCAAP) on the exercise status of school-age children with asthma. Methods: We included 400 school-age asthmatic children as research objects from CCAAP asthma management platform of the Affiliated Hospital of Qingdao University during March 1, 2018 to February 28, 2021 by simple random sampling method. The questionnaires of basic information and international physical activity were applied through WeChat or face to face investigation to collect the basic information and exercise status of the object. There were 346 valid questionnaires included in the study to compare the differences in exercise status and incidence of exercise-related asthma-like symptoms between the good and poor CCAAP application groups. Results: There were 232 (67.05%) and 114 (32.95%) cases in good and poor CCAAP application group, respectively. Age, female proportion and BMI of good CCAAP application group were (8±2) years, 47.0% (109/232) and (19.79±2.32) kg/m2, respectively, no statistic difference comparing to poor CCAAP application group [(8±2) years, 46.5% (53/114) and (19.87±2.43) kg/m2, respectively] (all P values>0.05). In good CCAAP application group, 30.18% (70/232) achieved the standard of moderate (high) intensity exercise per day, no statistic difference comparing to poor CCAAP application group [29.82% (34/112)] (P=0.947); 31.90% (74/232) participated in high-intensity exercise per week, higher than that of poor CCAAP application group [17.54% (20/112)] (P=0.005); incidence of exercise-related asthma-like symptoms was 19.83% (46/232), lower than that of poor CCAAP application group [29.82% (34/112)] (P=0.038). Conclusion: CCAAP promotes the exercise of school-age children with asthma.

Checkerboard immunoblotting recognizes twenty epitopes among the B subunit proteins of the cholera enterotoxin family.

Checkerboard immunoblotting (CBIB) was used to analyze the reactions of a series of monoclonal antibodies with proteins of the cholera enterotoxin (CT) family, including heat labile enterotoxins (LTs) produced by diarrheagenic strains of Escherichia coli and genetically engineered chimeric proteins in which single amino acids of the CT-B subunit protein or human (H) LT-B subunit protein were substituted for corresponding residues in porcine (P) LT-B. The result indicated that there were at least twenty different patterns of reactivity suggesting that there are at least twenty recognizable epitopes among the proteins studied. An epitope which includes Ala46 appears to be particularly important. This epitope is common to CT and H-LT but not P-LT, and the epitope is not blocked by the Gm1 ganglioside. Human convalescent sera react with this epitope. CBIB is a versatile technique for epitope analysis.

Urea-induced release of heat-labile enterotoxin from Escherichia coli.

Urea induces the release of heat-labile enterotoxin (LT) from cells of LT-producing Escherichia coli strains. Optimal conditions were defined by using the checkerboard immunoblotting system. LT release was highest when E. coli cells were incubated in 8 M urea, pH 8.0, at 37 degrees C in a water bath for 30 min. Urea was more effective than polymyxin B in inducing the release of LT antigen from E. coli; the activity of LT from urea-treated cells was seven times that of LT from polymyxin B-treated cells. Urea also increased the antigenic and biological reactivities of purified LT. This procedure is potentially applicable for the detection of LT-producing E. coli strains in the clinical laboratory.

Heterogeneity of immunotypes of heat-labile enterotoxins of enterotoxigenic Escherichia coli of human origin.

A new technique, checkerboard immunoblotting (CBIB), has been applied to detect and to differentiate heat-labile enterotoxins, (LTs), from enterotoxigenic strains of Escherichia coli of human origin using polyclonal and monoclonal antibodies. Optimal conditions of production and release of LTs were defined using CBIB. LT release was enhanced when E. coli cells were treated with 8 M urea. LT production was highest when E. coli strains were incubated with shaking (200 rpm) at 37 degrees C for 12 h in CAYE-2 medium. Two hundred and five strains of E. coli, isolated from patients with diarrhea in Japan, Thailand, the United States, Mexico, and Brazil, were examined for LT. Of 133 LT-positive strains, 4 (3%) produced an LT that reacted like H-LT-1 (originally isolated from E. coli strain H-74-114) while 126 strains (94.7%) produced LT that reacted like H-LT-2 (originally isolated from strain H-10407) or H-LT-3 (from strain H-240-3). Three strains of human origin (2.3%) produced an LT that reacted like P-LT (produced by E. coli strains of porcine origin). This study shows that CBIB, a simple, efficient, and practical assay, might be useful for epidemiologic surveys and for evaluation of serologic responses to LTs and antitoxic vaccines.