Objective To analyze the correlation between serum soluble Klotho protein(sKL)and tendino-C(TN-C)and the severity of disease and oxidative stress in children with immunoglobulin A(IgA)nephropa-thy.Methods A total of 85 children with IgA nephropathy admitted to the hospital from July 2019 to August 2022 were selected as IgA nephropathy group,and 85 healthy patients who underwent physical examination in the hospital during the same period were selected as healthy group.Serum sKL and TN-C levels were com-pared between the two groups.Receiver operating characteristic(ROC)curve was drawn to analyze the value of serum sKL,TN-C and their combination in predicting the occurrence of IgA nephropathy.IgA nephropathy group was divided into mild group(28 cases),moderate group(39 cases)and severe group(18 cases)accord-ing to 24 h urinary protein quantity.Serum sKL,TN-C levels and oxidative stress indexes[malondialdehyde(MDA),superoxide dismutase(SOD)and advanced oxidation protein product(AOPP)]of the three groups were compared.The correlation between serum sKL and TN-C levels and oxidative stress indexes was ana-lyzed by Spearman correlation,and the correlation between serum sKL and TN-C levels and the severity of IgA nephropathy in children was examined by Kendall's Tau-b.Results The serum sKL level in IgA ne-phropathy group was lower than that in healthy group,and the serum TN-C level was higher than that in healthy group,the difference was statistically significant(P＜0.05).ROC curve showed that the area under the curve and 95％CI of serum sKL,TNC and their combination predicted the occurrence of IgA nephropathy were 0.726(95％CI:0.648-0.803),0.853(95％CI:0.796-0.909)and 0.891(95％CI:0.845-0.937).The level of serum sKL in severe group was lower than that in moderate and mild groups,while the level of serum TN-C was higher than that in moderate and mild groups,and the difference was statistically significant(P＜0.05).The serum SOD level of severe group was lower than that of moderate group and mild group,and the serum AOPP and MDA levels were higher than those of moderate group and mild group,the difference was statistically significant(P＜0.05).Spearman correlation showed that sKL level was positively correlated with SOD(r＞0,P＜0.05),and negatively correlated with AOPP and MDA(r＜0,P＜0.05).TN-C level was negatively correlated with SOD(r＜0,P＜0.05),and positively correlated with AOPP and MDA(r＞0,P＜0.05).Conclusion The levels of serum sKL and TN-C in children with IgA nephropathy are related to the severity of disease and oxidative stress,and the combination of SKL and TN-C can effectively predict the occurrence of IgA nephropathy.

Objective:To investigate the effects of breast milk to total milk intake ratio during hospitalization on the duration of antibiotic therapy in preterm infants less than 34 weeks of gestation.Methods:Clinical data of preterm infants ( n=1 792) less than 34 gestational weeks were retrospectively collected in 16 hospitals of Jiangsu Province Neonatal-Perinatal Cooperation Network from January 1, 2019, to December 31, 2021. The days of therapy (DOT) were used to evaluate the duration of antibiotic administration. The median DOT was 15.0 d (7.0-27.0 d). The patients were divided into four groups based on the quartiles of DOT: Q 1 (DOT≤7.0 d), Q 2 (7.0 d27.0 d) groups. According to the breast milk intake ratio (breast milk intake to total milk intake during hospitalization×100%), they were also divided into four groups: very-low-ratio breastfeeding group (breast milk intake ratio≤25%), low-ratio breastfeeding group (25%75%). Univariate analysis ( Chi-square test and Kruskal-Wallis rank-sum test) was used to analyze the factors influencing DOT. Spearman correlation analysis and trend Chi-square test were used to explore the relationship between breast milk intake ratio and DOT. After using multiple imputations to address missing data, two models were constructed after adjusting for different factors, and multinomial logistic regression model was applied to evaluate the effects of the breast milk intake ratio on DOT. Finally, sensitivity analysis was conducted to assess the stability of the models. Results:(1) Of the 1 792 preterm infants, there were 507 (28.3%) in the Q 1 group, 422 (23.5%) in the Q 2 group, 438 (24.4%) in the Q 3 group and 425 (23.7%) in the Q 4 group. (2) The median values of DOT in the very-low-ratio, low-ratio, medium-ratio and high-ratio breastfeeding groups were 20.0 d (11.0-31.0 d), 20.0 d (11.0-32.0 d), 13.0 d (6.0-25.8 d) and 10.0 d (4.0-21.0 d), respectively. Compared with the very-low-ratio and low-ratio breastfeeding groups, the medium-ratio and high-ratio breastfeeding groups had shorter DOT (all P<0.05). (3) After adjusting for factors with P<0.1 (prenatal glucocorticoid exposure, antimicrobial use within 24 h before delivery, gestational age at delivery, birth weight, Apgar score≤7 at 1 min, neonatal respiratory distress syndrome, infectious pneumonia and early-onset neonatal sepsis) between the DOT quartile groups, it showed that medium-ratio and high-ratio breastfeeding were protective factors in contrast to very-low-ratio breastfeeding in the Q 2, Q 3 and Q 4 groups as compared with the Q 1 group [Q 2 group: OR=0.50 (95% CI: 0.30-0.85) and OR=0.36 (95% CI: 0.26-0.51); Q 3 group: OR=0.31 (95% CI: 0.18-0.55) and OR=0.20 (95% CI: 0.14-0.29); Q 4 group: OR=0.22 (95% CI: 0.12-0.42) and OR=0.17 (95% CI: 0.12-0.26)]. Conclusion:Breast milk intake accounting for over 50% of total milk intake has a positive impact on reducing DOT in premature infants requiring antibiotics, which suggests that breastfeeding should be actively encouraged.