ABSTRACT
<p><b>Background</b>Fine particulate matter (PM) exacerbates airway inflammation and hyperreactivity in patients with asthma, but the mechanism remains unclear. The aim of this study was to observe the effects of prolonged exposure to high concentrations of PMon the pathology and airway hyperresponsiveness (AHR) of BALB/c mice undergoing sensitization and challenge with ovalbumin (OVA) and to observe the effects of apoptosis and T-cell immunoglobulin and mucin domain 1 (TIM-1) in this process.</p><p><b>Methods</b>Forty female BALB/c mice were divided into four groups: control group, OVA group, OVA/PM group, and PM group (n = 10 in each group). Mice in the control group were exposed to filtered clean air. Mice in the OVA group were sensitized and challenged with OVA. Mice in the OVA/PM group were sensitized and challenged as in the OVA group and then exposed to PMfor 4 h per day and 5 days per week for a total of 8 weeks using a nose-only "PMonline enrichment system" in The Second Hospital of Hebei Medical University. Mice in the PM group were exposed to the PM online enrichment system only. AHR was detected. Bronchoalveolar lavage fluid (BALF) was collected for cell classification. The levels of interleukin-4 (IL-4), IL-5, and IL-33 in BALF were measured using enzyme-linked immunosorbent assay. Changes in histological structures were examined by light microscopy, and changes in ultramicrostructures were detected by electron microscopy. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay in the lung tissues. Western blotting and immunohistochemistry were utilized to analyze the expression of Bcl-2, Bax, and TIM-1 in the lungs.</p><p><b>Results</b>The results showed that AHR in the OVA/PM group was significantly more severe than that in the OVA and PM groups (P < 0.05). AHR in the PM group was also considerably more severe than that in the control group (P < 0.05). The BALF of OVA/PM group (28.00 ± 6.08 vs. 12.33 ± 4.51, t = 4.631, P = 0.002) and PM group (29.00 ± 3.00 vs. 12.33 ± 4.51, t = 4.927, P = 0.001) had more lymphocytes than the BALF of the control group. The number of neutrophils in the BALF of the OVA/PM group (6.67 ± 1.53 vs. 3.33 ± 1.53, t = 2.886, P = 0.020) and PM group (6.67 ± 1.53 vs. 3.33 ± 1.53, t = 2.886, P = 0.020) was much higher than those in the BALF of OVA group (P < 0.05). TUNEL assays showed that the number of apoptotic cells in the OVA/PM group was significantly higher than that in the OVA group (Tunel immunohistochemical scores [IHS%], 1.20 ± 0.18 vs. 0.51 ± 0.03, t = 8.094, P < 0.001) and PM group (Tunel IHS%, 1.20 ± 0.18 vs. 0.51 ± 0.09, t = 8.094, P < 0.001), and that the number of apoptotic cells in the PM group was significantly higher than that in the control group (Tunel IHS%, 0.51 ± 0.09 vs. 0.26 ± 0.03, t = 2.894, P = 0.020). The concentrations of IL-4 (77.44 ± 11.19 vs. 48.02 ± 10.02 pg/ml, t = 4.595, P = 0.002) and IL-5 (15.65 ± 1.19 vs. 12.35 ± 0.95 pg/ml, t = 3.806, P = 0.005) and the Bax/Bcl-2 ratio (1.51 ± 0.18 vs. 0.48 ± 0.10, t = 9.654, P < 0.001) and TIM-1/β-actin ratio (0.78 ± 0.11 vs. 0.40 ± 0.06, t = 6.818, P < 0.001) in the OVA/PM group were increased compared to those in the OVA group. The concentrations of IL-4 (77.44 ± 11.19 vs. 41.47 ± 3.40 pg/ml, t = 5.617, P = 0.001) and IL-5 (15.65 ± 1.19 vs. 10.99 ± 1.40 pg/ml, t = 5.374, P = 0.001) and the Bax/Bcl-2 ratio (1.51 ± 0.18 vs. 0.97 ± 0.16, t = 5.000, P = 0.001) and TIM-1/β-actin ratio (0.78 ± 0.11 vs. 0.31 ± 0.06, t = 8.545, P < 0.001) in the OVA/PM group were increased compared to those in the PM group. The concentration of IL-4 (41.47 ± 3.40 vs. 25.46 ± 2.98 pg/ml, t = 2.501, P = 0.037) and the Bax/Bcl-2 ratio (0.97 ± 0.16 vs. 0.18 ± 0.03, t = 7.439, P < 0.001) and TIM-1/β-actin ratio (0.31 ± 0.06 vs. 0.02 ± 0.01, t = 5.109, P = 0.001) in the PM group were also higher than those in the control group.</p><p><b>Conclusions</b>Exacerbated AHR associated with allergic asthma caused by PMis related to increased apoptosis and TIM-1 activation. These data might provide insights into therapeutic targets for the treatment of acute exacerbations of asthma induced by PM.</p>
ABSTRACT
<p><b>BACKGROUND</b>The 2009 pandemic H1N1 (pH1N1) influenza showed that relatively young adults accounted for the highest rates of hospital admission and death. In preparation for pH1N1, the aim of the study is to identify factors associated with the mortality of patients with 2009 pH1N1 infection, especially for young patients without chronic medical conditions.</p><p><b>METHODS</b>Retrospective observational study of 2151 severe or critical adult cases (≥ 14 years old) admitted to a hospital with pH1N1 influenza from September 1, 2009 to December 31, 2009 from 426 hospitals of 27 Chinese provinces. A confirmed case was a person whose pH1N1 virus infection was verified by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Severe and critical cases were defined according to the H1N1 2009 Clinical guidelines (Third Edition, 2009) released by the Ministry of Health of China.</p><p><b>RESULTS</b>Among the 2151 patients, the mean age was 34.0 years. Two hundred and ninty-three (13.6%) died during hospital stay. One thousand four hundred and forty-two patients (67.0%) had no comorbidities and 189 (13.1%) of them died. Pregnancy (OR 8.03), pneumonia (OR 8.91), dyspnea (OR 3.95), central nervous system (CNS) symptom (OR 1.55), higher APACHE (Acute Physiology and Chronic Health Evaluation) II score (OR 1.06), Alanine aminotransferase (ALT) (OR 1.002), and the lactate dehydrogenase (LDH) level (OR 1.001) were independent risk factors for death among adults without chronic medical conditions. Higher APACHE II score (OR 1.08) and age (OR 1.06) were independent risk factors for death among adults with respiratory diseases. A multivariate analysis showed an association between mortality and CNS symptoms (OR 2.66), higher APACHE II score (OR 1.03), ALT (OR 1.006), and LDH level (OR 1.002) in patients with cardiovascular diseases. Dyspnea (OR 11.32) was an independent risk factor for patient death in patients with diabetes mellitus.</p><p><b>CONCLUSION</b>Clinical knowledge of identified prognostic factors for mortality may aid in the management of adult influenza infection.</p>