RESUMO
OBJECTIVES: To study the clinical characteristics and pathogen features of infants with bronchopulmonary dysplasia (BPD) who were readmitted during infancy due to lower respiratory tract infections. METHODS: A retrospective analysis was conducted on 128 preterm infants with BPD who were admitted for lower respiratory tract infections in Qingdao Women and Children's Hospital from January 2020 to December 2022. An equal number of non-BPD preterm infants admitted during the same period were selected as controls. General information, clinical characteristics, lung function parameters, and respiratory pathogen results were compared between the two groups. RESULTS: Compared with the non-BPD group, the BPD group had a lower gestational age and birth weight, were more likely to experience shortness of breath, wheezing, and cyanosis, and had a longer duration of wheezing relief (P<0.05). Compared with the non-BPD group, the BPD group had lower lung function parameters, including tidal volume per kilogram of body weight, ratio of time to peak tidal expiratory flow to total expiratory time, ratio of volume at peak tidal expiratory flow to expiratory tidal volume, tidal expiratory flow at 25%, 50%, and 75% of tidal volume, and increased respiratory rate (P<0.05). The detection rates of gram-negative bacteria, such as Klebsiella pneumoniae and Acinetobacter baumannii, were higher in the BPD group than in the non-BPD group (P<0.05). CONCLUSIONS: Infants with BPD who develop infancy lower respiratory tract infections require closer attention to the clinical characteristics such as shortness of breath, wheezing, and cyanosis. Lung function is characterized by obstructive changes and small airway dysfunction. Gram-negative bacteria, including Klebsiella pneumoniae and Acinetobacter baumannii, are more likely to be detected as respiratory pathogens.
RESUMO
OBJECTIVE: To investigate the effects of peroxisome proliferator-activated receptor-gamma (PPARγ) agonist rosiglitazone on the expression of cyclin D1 in lung tissue, and the proliferation of airway smooth muscle cells (ASMCs) in mice with bronchial asthma. METHODS: Thirty clean BALB/c mice were randomly divided into control group (n = 10), asthma group (n = 10), and rosiglitazone treatment group (n = 10). A mouse model of asthma was established by ovalbumin (OVA) sensitization and challenge. The treatment group received rosiglitazone (5 mg/kg) by gavage 1 hour before each challenge and the control group received saline instead of OVA sensitization and challenge. Leukocytes and eosinophils in bronchoalveolar lavage fluid (BALF) were counted under a microscope. Airway structural changes were observed by hematoxylin-eosin staining. Protein and mRNA expression levels of cyclin D1 were measured by immunohistochemical staining and RT-PCR. Perimeter of the basement membrane (Pbm), total bronchial wall area (WAt), airway smooth muscle area (WAm), and number of nuclei in ASMCs (N) were determined using image analysis software, and WAt/Pbm, WAm/Pbm, and N/Pbm were calculated. RESULTS: Compared with the control group, the asthma group showed significant increases in the total number of leukocytes and percentage of eosinophils in BALF, as well as in the mRNA and protein expression of cyclin D1, but changes in these indices were significantly reduced in the rosiglitazone treatment group (P < 0.05). In addition, compared with the control group, the asthma group had significantly increased WAt/Pbm, WAm/Pbm, and N/Pbm, but rosiglitazone significantly decreased these ratios (P < 0.05). CONCLISONS: Rosiglitazone may delay the process of airway remodeling by inhibiting the proliferation of ASMCs, so it can be used for preventing and treating chronic asthma.