Chronic diesel exhaust exposure induced pulmonary vascular remodeling a potential trajectory for traffic related pulmonary hypertension.

BACKGROUND: As one of the most common traffic-related pollutants, diesel exhaust (DE) confers high risk for cardiovascular and respiratory diseases. However, its impact on pulmonary vessels is still unclear. METHODS: To explore the effects of DE exposure on pulmonary vascular remodeling, our study analyzed the number and volume of small pulmonary vessels in the diesel engine testers (the DET group) from Luoyang Diesel Engine Factory and the controls (the non-DET group) from the local water company, using spirometry and carbon content in airway macrophage (CCAM) in sputum. And then we constructed a rat model of chronic DE exposure, in which 12 rats were divided into the DE group (6 rats with 16-week DE exposure) and the control group (6 rats with 16-week clean air exposure). During right heart catheterization, right ventricular systolic pressure (RVSP) was assessed by manometry. Macrophage migration inhibitory factor (MIF) in lung tissues and bronchoalveolar lavage fluid (BALF) were measured by qRT-PCR and ELISA, respectively. Histopathological analysis for cardiovascular remodeling was also performed. RESULTS: In DET cohort, the number and volume of small pulmonary vessels in CT were positively correlated with CCAM in sputum (P<0.05). Rat model revealed that chronic DE-exposed rats had elevated RVSP, along with increased wall thickness of pulmonary small vessels and right the ventricle. What's more, the MIF levels in BALF and lung tissues were higher in DE-exposed rats than the controls. CONCLUSION: Apart from airway remodeling, DE also induces pulmonary vascular remodeling, which will lead to cardiopulmonary dysfunction.

[Quantitative measurement of cross-sectional area of small pulmonary vessels in pulmonary embolism].

Objective: The relationship between the percentage of total cross-sectional area (% CSA) of small pulmonary vessels for the lung area in CTPA and the right ventricular function parameters in patients with pulmonary embolism. Methods: 120 patients with PE and 72 healthy subjects underwent CTPA and all date were analyzed Retrospectively. The main pulmonary artery diameter (mPA), the ratio of the main pulmonary artery to the ascending aorta diameter (rPA), right ventricle/left ventricular diameter ratio (RVd/LVd), and the pulmonary artery obstruction index (PAOI) in the PE group were measured for all subjects. The %CSA<5 mm(2) and 5-10 mm(2) for the lung area (%CSA(<5) and %CSA(5-10)) of small pulmonary vessels were measured with Image J image-processing program. According to the risk stratification of the 2018 Guidelines for the Diagnosis and Treatment of Pulmonary Thromboembolism, PE patients were divided into medium-high risk group (RVd/LVd>1) and low-risk group (RVd/LVd<1). The indexes of PE in medium-high risk group, low risk group and control group were compared by ANOVA, and the indexes among PE subgroups were compared by independent sample t-test. Spearman correlation method was used to analyze the correlation between %CSA and right ventricular function parameters of PE patients. Results: %CSA(<5) of medium-high risk group, low-risk group and control group were (0.69±0.19)%, (0.95±0.27)% and (0.99±0.30)% (P<0.01), respectively. %CSA(5-10) of three groups were (0.63±0.15)%, (0.84±0.18)%, and (0.85±0.25)% (P<0.01), respectively; %CSA(<5) and %CSA(5-10) of medium-high risk group were lower than low-risk group and control group. %CSA(<5) and %CSA(5-10) in PE patients correlated negatively with RVd/LVd, rPA and mPA (r=-0.545/-0.549, -0.235/-0.352, -0.239/-0.298, respectively). Conclusion: The measurement of % CSA<(5) and %CSA (5-10) in CTPA were negatively correlated with RVd/LVd in patients with pulmonary embolism, which indirectly reflected the severity of the pulmonary embolism patients.

Relationship between diminution of small pulmonary vessels and emphysema in chronic obstructive pulmonary disease.

OBJECTIVES: To investigate the relationship between small pulmonary vessels and extent of emphysema on CT in individual lungs with chronic obstructive pulmonary disease (COPD). METHODS: Forty-nine patients were included. The percentage of cross-sectional area of vessels <5mm2 (%CSA <5) and extent of emphysema were assessed. RESULTS: Less than half of the COPD patients demonstrated an inverse correlation between %CSA <5 and percentage of low attenuation area (LAA%). In the remaining patients, %CSA <5 was homogeneously distributed. CONCLUSION: Not all patients with COPD demonstrated an inverse correlation of the distributions between %CSA <5 and LAA% in individual lungs.