BACKGROUND:Proanthocyanidin,a kind of grape seed extract(GSE),has the effect of anti-oxidation and elimination of free radicals.Research finds that increase of free radicals in skeletal muscle and active oxygen in other forms induced by exercise is one of the important causes of the injury and fatigue of skeletal muscle. Supplement of antioxidant can inhibit this kind of change and improve motor ability. OBJECTIVE:To study the anti-fatigue effects of proanthocyanidin. DESIGN:A completely randomized controlled experimental study taking experimental animals as the subjects. SETTING:A toxicological department of a provincial center for disease control and prevention. PARTICIPANTS:The experiment was completed in the Department of Toxicology,Jiangsu Center for Disease Control and Prevention from September to December 2001.Male mice of Kunming strain and common grade[certification number:SCXK(Su) 2002-0011;certification number of environmental equipment for experimental animal:SYXK(Su) 2001-0004]were purchased from the Experiment Animal Center of Chinese Pharmacological University.The 120 mice were randomly divided according to body mass into control group and 3 experiment groups, namely,low-,medium-and high-dose GSE groups,with 10 mice in each group.The mice in the 3 experiment groups received oral administration of GSE every day. INTERVENTIONS:The mice in the 3 experiment groups received oral administration of GSE of 1.7, 16.7 and 50.0 mg/kg body mass,respectively,while those in control group were only given twice distilled water for 30 consecutive days. After GSE treatment for 30 days,the loaded swimming time, contents of hepatic glycogen,blood lactic acid(LA) and hemoglobin were measured. MAIN OUTCOME MEASURES:Loaded swimming time, hepatic glycogen,LA and hemoglobin contents. RESULTS:The loaded swimming time of mice in experiment groups was significantly prolonged as compared with that in control group (P< 0.01),with(17.84± 8.48) and(25.80± 7.45) minutes in medium-and high-dose GSE groups,respectively.LA content after exercise in experiment groups was all lower than that in control group,with greatly significant difference between high-dose GSE group[(6.78± 2.45) mmol/L] and control group[(9.98± 1.22) mmol/L](P< 0.01).The content of hepatic glycogen after exercise in experiment groups was higher than that in control group; medium-dose GSE group[(1 244.65(177.58) mg/100 g liver mass]and high-dose GSE group[(1 383.96± 141.20) mg/100 g liver mass]differed greatly significantly from control group[(817.67(114.72) mg/100 g liver mass](P< 0.05,P< 0.01). CONCLUSION:Grape seed extract proanthocyanidin has an anti-fatigue effect.

Objective:To analyze the risk factors of bronchopulmonary dysplasia(BPD)in very preterm infants(VPI), and to provide scientific basis for the prevention and treatment of BPD in VPI.Methods:A prospective multicenter study was designed to collect the clinical data of VPI in department of neonatology of 28 hospitals in 7 regions from September 2019 to December 2020.According to the continuous oxygen dependence at 28 days after birth, VPI were divided into non BPD group and BPD group, and the risk factors of BPD in VPI were analyzed.Results:A total of 2 514 cases of VPI including 1 364 cases without BPD and 1 150 cases with BPD were enrolled.The incidence of BPD was 45.7%.The smaller the gestational age and weight, the higher the incidence of BPD( P<0.001). Compared with non BPD group, the average birth age, weight and cesarean section rate in BPD group were lower, and the incidence of male infants, small for gestational age and 5-minute apgar score≤7 were higher( P<0.01). In BPD group, the incidences of neonatal respiratory distress syndrome(NRDS), hemodynamically significant patent ductus arteriosus, retinopathy of prematurity, feeding intolerance, extrauterine growth restriction, grade Ⅲ~Ⅳ intracranial hemorrhage, anemia, early-onset and late-onset sepsis, nosocomial infection, parenteral nutrition-associated cholestasis were higher( P<0.05), the use of pulmonary surfactant(PS), postnatal hormone exposure, anemia and blood transfusion were also higher, and the time of invasive and non-invasive mechanical ventilation, oxygen use and total hospital stay were longer( P<0.001). The time of starting enteral nutrition, cumulative fasting days, days of reaching total enteral nutrition, days of continuous parenteral nutrition, days of reaching 110 kcal/(kg·d) total calorie, days of reaching 110 kcal/(kg·d) oral calorie were longer and the breastfeeding rate was lower in BPD group than those in non BPD group( P<0.001). The cumulative doses of amino acid and fat emulsion during the first week of hospitalization were higher in BPD group( P<0.001). Multivariate Logistic regression analysis showed that NRDS, invasive mechanical ventilation, age of reaching total enteral nutrition, anemia and blood transfusion were the independent risk factors for BPD in VPI, and older gestational age was the protective factor for BPD. Conclusion:Strengthening perinatal management, avoiding premature delivery and severe NRDS, shortening the time of invasive mechanical ventilation, paying attention to enteral nutrition management, reaching whole intestinal feeding as soon as possible, and strictly mastering the indications of blood transfusion are very important to reduce the incidence of BPD in VPI.