【Abstract】 Objective To investigate the effects of respiratory syncytial virus ( RSV) infection on the dynamic changes of airway hyperresponsiveness ( AHR) in ovalbumin ( OVA) -induced asthma in mice.Methods 60 BALB/c female mice were randomly divided into PBS control group ( A group, n = 6) , OVA group, OVA/RSV group, dexamethasone group ( D group, n =6) . Kinetics of AHR of OVA group mice was carried out on day 21, 25, 29 and 33 ( B1, B2, B3, B4 groups, n =6) , and the same with the OVA /RSV group( C1, C2, C3, C4 groups, n = 6 ) . The mouse asthma model was established by OVA-sensitization of intraperitoneal injection and repeated inhalation of OVA while the mice in OVA/RSV group were treated with combined intranasal inoculation with RSV ( 1. 0 ×106 pfu/mL in 50 μL) . Airway resistance of expiringphase ( RL ) and compliance of throax and lung ( CTL ) with different doses of acetylcholine ( Ach) were measured. Lung tissue sections were stained with hematoxylin and eosin ( HE) and periodic acid-Schiff ( PAS) for general morphology. Results Compared with B1 group, RL increased and CTL decreased in C1 group when Ach dose is above 5 g/L ( P lt; 0. 05, respectively) , and the effects prolonged ( 6 d, 10 d after challenge with OVA, respectively) much more than B1 group ( 2 d after challenge with OVA) . Compared with C1 group, RL decreased and CTL increased in D group and the infiltration of inflammatory cells was obviously alleviated in C1 group after treatment with dexamethasone. Conclusions Airway hyperresponsiveness increases obviously in OVA-sensitized and RSV-infected mice. The prolonged increase inRL and decrease in CTL ( 6 d, 10 d, respectively) may imply that RSV infection aggravates airway inflammation. The small airway inflammation may play a critical role in the persistence of airway hyperresponsiveness.
Objective To explore the clinical characteristics of Chlamydia psittaci pneumonia. Methods From January 2020 to March 2023, 21 cases of Psittacosis from the First Affiliated Hospital of Nanjing Medical University were diagnosed via metagenomic next-generation sequencing (mNGS). They were divided into a severe group (n=10) and a non-severe group (n=11) based on diagnostic criteria for severe pneumonia, and the clinical presentation, secondary examination, treatment, and prognosis of the two groups were analyzed retrospectively. Results Among the 21 patients, there were 11 males and 10 females, with a mean age of (51.7±11.6) years. All patients had an acute onset and 12 had a confirmed history of exposure to poultry. The onset of the disease occurred in the autumn and winter seasons in 18 patients. All the patients were suffering from high fevers. Other symptoms included coughing, phlegm, tightness in the chest and fatigue. Laboratory examinations showed that the levels of leukocytes, neutrophil counts, C-reactive protein, procalcitonin, aminotransferase, creatine kinase, lactic dehydrogenase, brain natriuretic peptide precursors and D-dimer were significantly higher in the severe group than those in the non-severe group. Chest CT scans revealed varying levels of consolidation and spot shadowing with peripheral exudate in all patients. The patients in the severe group were more likely to have bilateral lung involvement, bilateral pleural effusion, cavity and mediastinal lymph node enlargement. Eleven patients received tetracycline alone, three received laudanum alone, two received respiratory quinolones alone, and five received a combination of two drugs including tetracycline. Chest CT at clinical follow-up showed absorption of lung lesions. Conclusions Chlamydia psittaci pneumonia usually occurs in the fall and winter, and most patients have a history of contact with poultry. Clinical presentation and imaging are not specified. The technology of mNGS enables early diagnosis of the disease, and neutrophil lymphocyte ratio, neutrophil-lymphocyte ratio and lactic dehydrogenase levels help assess the risk of severe disease.