[Clinical characteristics and pathogens of infancy lower respiratory tract infections in infants with bronchopulmonary dysplasia]. / æ”¯æ°”ç®¡è‚ºå‘è‚²ä¸è‰¯æ‚£å„¿å©´å„¿æœŸä¸‹å‘¼å¸é“æ„ŸæŸ“çš„ä¸´åºŠç‰¹å¾åŠç— åŽŸå­¦åˆ†æž.

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.

[Effect of peroxisome proliferator-activated receptor-gamma on proliferation of airway smooth muscle cells in mice with asthma].

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.

[Effects of fasudil on the expression of Rho kinase-1 and airway inflammation in a mouse model of asthma.].

OBJECTIVE: To explore the role of Rho kinase-1 (ROCK-1) in airway inflammation of asthma by observing the effects of fasudil, a specific inhibitor of ROCK-1, on the expression of Rho kinase-1 and airway inflammation in a mouse model of asthma. METHODS: Twenty-four female BALB/c mice were randomly divided into 3 groups (n = 8 each): a control group, an asthmatic group and a treatment group. Mice in the asthmatic and the treatment groups were sensitized by intraperitoneal injection of OVA (25 microg) precipitated with 1 mg of alum in 200 microl of saline on days 1 and 15, and subsequently challenged by nebulization of 2% OVA on days 22-26. Mice in the control group were sensitized with Al(OH)3 saline and challenged with saline instead of OVA. Mice of the treatment group were injected intraperitoneally with fasudil (10 mg/kg) 1 h before each OVA challenge. All the mice were killed 24 h after the final challenge, and bronchoalveolar lavage fluid (BALF) was collected for counting total inflammatory cells and eosinophils (EOS). Cytokines and chemokines in BALF were measured by ELISA. The lung tissue slides were examined histologically. The protein and mRNA expression of ROCK-1 were measured by immunohistochemistry and RT-PCR respectively. RESULTS: (1) OVA challenge in mice of the asthmatic group caused a marked increase in the number of the total cells and eosinophils in BALF (q = 25.909, 35.002, respectively, all P < 0.01). When fasudil was applied, both the total cell counts and the eosinophil numbers were significantly decreased. The total cell number was decreased from (1.45 +/- 0.12) x 10(9)/L to (0.89 +/- 0.09) x 10(9)/L (q = 16.676, P < 0.01), and the number of eosinophils was decreased from (0.52 +/- 0.06) x 10(9)/L to (0.20 +/- 0.04) x 10(9)/L (q = 21.537, P < 0.01). (2) Compared with the control group, OVA challenge in mice of the asthmatic group induced eotaxin, IL-5 and IL-13 release into BALF (q = 18.246, 23.009, 25.826, respectively, all P < 0.01). The eotaxin, IL-5 and IL-13 levels in BALF after OVA challenge were (45 +/- 8) ng/L, (157 +/- 23) ng/L and (429 +/- 46) ng/L, respectively. Application of fasudil resulted in inhibition of the augmented levels of eotaxin, IL-5 and IL-13 in BALF, decreased to (20 +/- 5) ng/L, (57 +/- 14) ng/L and (254 +/- 28) ng/L, respectively (q = 13.119, 17.503, 8.449, respectively, all P < 0.01). (3) Mice in the control group showed no detectable inflammatory response in the lung, whereas OVA-challenged mice induced infiltration of inflammatory cells around airways and blood vessels. The majority of the infiltrated inflammatory cells were eosinophils. Application of fasudil significantly reduced the infiltration of inflammatory cells in the peribronchial areas compared with the asthmatic mice. (4) The expression levels of ROCK-1 mRNA and protein in mice of the asthmatic group (0.67 +/- 0.05 and 1.09 +/- 0.06) were much higher than those of the control group (0.26 +/- 0.05 and 0.87 +/- 0.09) (q = 25.614, 8.156, all P < 0.01). When fasudil was administered, the expression levels of ROCK-1 mRNA and protein were significantly attenuated to 0.35 +/- 0.04 and 0.98 +/- 0.08, compared with those of the asthmatic group (q = 20.379, 4.135, all P < 0.01). (5) The expression level of ROCK-1 mRNA was positively correlated with the number of eosinophils and the levels of eotaxin, IL-5 and IL-13 in BALF (r = 0.709, 0.600, 0.613, 0.650, all P < 0.01). CONCLUSION: Airway inflammation of bronchial asthma was improved by inhibiting expression and activity of ROCK-1 by fasudil, suggesting that ROCK-1 may be involved in asthmatic airway inflammation induced by OVA challenge.