ObjectiveTo investigate the influenza virus infection status of influenza-like illness (ILI) at a sentinel hospital in Baoshan District of Shanghai, to explore the seasonal patterns of influenza, so as to provide a scientific basis for influenza prevention and control in Baoshan District of Shanghai. MethodsSurveillance data and pathogenic testing results of ILI from the monitoring year of 2015 to 2023 were collected from the sentinel hospital to describe the seasonal epidemic characteristics of influenza in this district. ResultsThe proportion of ILI visits to sentinel hospital in Baoshan District of Shanghai showed an upward trend from 2015 to 2023 (Z=2.598, P=0.09). The positive rate of influenza virus in ILI was 20.43% (1 761/8 621), of which 14.17% were positive for influenza A virus, including 8.43% for influenza A/H3N2 and 5.74% for influenza A/H1N1. The positive rate of influenza B virus was 6.25%, of which the positive detection rate of influenza B/Victoria virus was 5.35%, while that of influenza B/Yamagata virus was 0.90%. Influenza B/Yamagata virus was not detected in 2019‒2023. The highest positivity rate was observed in the 5‒<15 years age group (25.57%). The positive rate of ILI was lower in males (19.90%) than that in females (20.90%). There were three patterns of influenza epidemic in the district: with year-round circulation in 2016‒2017 and 2021‒2022; with bimodal peaks in 2015‒2016, 2017‒2018 and 2022‒2023; and with one peak in 2018‒2019 and 2019‒2020. The positive rate of influenza virus exhibited seasonal variations, with influenza A virus predominated in summer and autumn. However, influenza B virus showed an increase in spring and winter. ConclusionThe influenza epidemic in Baoshan District, Shanghai exhibits diverse patterns with heterogeneous epidemiological characteristics across different age groups and seasons. Notably, children and adolescents aged 5‒<15 years constitute the key target population for influenza prevention and control. Enhanced surveillance and targeted control measures against influenza A/H3N2 lineage viruses are particularly warranted during summer and autumn seasons.

Objective This study aimed to investigate the renal expression change of high mobility of nucleosome binding protein 1 ( HMGN1) in epithelia-mesenchymal transition ( EMT) process, and to study the effect of HMGN1 on renal fibrosis in the diabetic nephropathy mice model. Methods 20 C57BL/6 mice were randomly divided into control group, model group, benazepril group, and insulin group. After 8 weeks of drug intervention, blood, urine and kidney tissue samples were taken from mice. The routine physiological and biochemical indexes were detected. Renal structure and fibrosis were detected by HE and Sirius red staining, respectively. Immunohistochemistry and in situ hybridization were used to investigate the protein and mRNA expression levels of HMGN1, CD68, F4/80,α-smooth muscle actin (α-SMA) , and E-cadherin in renal tissue. Results Blood glucose, renal index, and urinary albumin to creatinine ratio ( UACR) were significantly higher in the model group than those in the normal group. In the model group, HE staining showed glomerular hypertrophy and interstitial inflammatory cell infiltration, and Sirius red showed collagen deposition in the renal tissue. Compared with normal group, HMGN1, CD68, F4/80 positive cell counts andα-SMA protein expression were all increased, while E-cadherin protein expression was downregulated in the model group ( all P<0.05) . The above indexes were not improved significantly in the benazepril group. And after intervention of insulin, the expression levels of CD68 positive cell count andα-SMA protein were decreased and the expression levels of E-cadherin protein were increased compared with the model group ( all P<0.05) . The correlation analysis showed that the level of HMGN1 was correlated with CD68, F4/80, α-SMA, E-cadherin and collagen protein, while CD68 and f4/80 were correlated withα-SMA, collagen protein and blood glucose, respectively ( all P<0. 05 ) . Conclusion HMGN1 is involved in the progression of diabetic nephropathy fibrosis, and its underlying mechanism might be related to the macrophage-mediated EMT process.