Enhanced Lyn Activity Causes Severe, Progressive Emphysema and Lung Cancer

The epidemiological patterns of incident chronic obstructive pulmonary disease (COPD) and lung adenocarcinoma are changing, with an increasing fraction of disease occurring in patients who are never-smokers or were not exposed to traditional risk factors. However, causative mechanism(s) are obscure. Overactivity of Src family kinases (SFKs) and myeloid cell-dependent inflammatory lung epithelial and endothelial damage are independent candidate mechanisms, but their pathogenic convergence has not been demonstrated. Here we present a novel preclinical model in which an activating mutation in Lyn, a nonreceptor SFK that is expressed in immune cells, epithelium, and endothelium-all strongly implicated in the pathogenesis of COPD-causes spontaneous inflammation, early-onset progressive emphysema, and lung adenocarcinoma. Surprisingly, even though activated macrophages, elastolytic enzymes, and proinflammatory cytokines were prominent, bone marrow chimeras formally demonstrated that myeloid cells were not disease initiators. Rather, lung disease arose from aberrant epithelial cell proliferation and differentiation, microvascular lesions within an activated endothelial microcirculation, and amplified EGFR (epidermal growth factor receptor) expression. In human bioinformatics analyses, LYN expression was increased in patients with COPD and was correlated with increased EGFR expression, a known lung oncogenic pathway, and LYN was linked to COPD. Our study shows that a singular molecular defect causes a spontaneous COPD-like immunopathology and lung adenocarcinoma. Furthermore, we identify Lyn and, by implication, its associated signaling pathways as new therapeutic targets for COPD and cancer. Moreover, our work may inform the development of molecular risk screening and intervention methods for disease susceptibility, progression, and prevention of these increasingly prevalent conditions.

Association of impaired lung function with dementia, and brain magnetic resonance imaging indices: a large population-based longitudinal study

OBJECTIVE

to examine the association between different patterns of impaired lung function with the incident risk of dementia and magnetic resonance imaging (MRI)-based brain structural features.

METHODS

in UK Biobank, a total of 308,534 dementia-free participants with valid lung function measures (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) were included. Association was assessed using Cox proportional hazards regression model. Furthermore, the association between impaired lung function and brain MRI biomarkers related to cognitive function was analysed among 30,159 participants.

RESULTS

during a median follow-up of 12.6 years, 3,607 incident all-cause dementia cases were recorded. Restrictive impairment (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.27-1.60) and obstructive impairment (HR, 1.28; 95% CI, 1.15-1.42) were associated with higher risk of all-cause dementia. The restricted cubic splines indicated FEV1% predicted and FVC % predicted had reversed J-shaped associations with dementia. Participants with impaired lung function have higher risks of all-cause dementia across all apolipoprotein E (APOE) risk categories, whereas associations were stronger among those of low APOE risk (P for interaction = 0.034). In addition, restrictive and obstructive impairment were linked to lower total (β: -0.075, SE: 0.021, Pfdr = 0.002; β: -0.033, SE: 0.017, Pfdr = 0.069) and frontoparietal grey matter volumes, higher white matter hyperintensity, poorer white matter integrity, lower hippocampus (β: -0.066, SE: 0.024, Pfdr = 0.017; β: -0.051, SE: 0.019, Pfdr = 0.019) and other subcortical volumes.

CONCLUSIONS

participants with restrictive and obstructive impairments had a higher risk of dementia. Brain MRI indices further supported adverse effects and provided insight into potential pathophysiology biomarkers.

Incense (bakhour) smoke exposure is associated with respiratory symptoms and impaired lung function among adults: A cross-sectional study in Eastern Province of Saudi Arabia

Burning incense (bakhour) is a common cultural practice in Saudi Arabia. However, its health risk assessment has rarely been studied. This study aims to investigate the association between exposure to incense smoke on lung function impairments and respiratory symptoms among young adults in Saudi Arabia. A community-based cross-sectional study was designed with a representative study sample (N = 125) in the Eastern Province of Saudi Arabia. Study participants, exposed group (n = 45), working in bakhour shop and matched control (n = 80), no history of occupational exposure to bakhour smoke, were recruited randomly from the population registry. Socio-demographic and respiratory symptom information were collected through a questionnaire developed based on European Community Respiratory Health Survey II (ECRHS II). Lung function measurements were conducted using a field spirometer. The overall prevalence of wheezing or whistling was 16.8%, with a higher prevalence in exposed group 35.5%. In adjusted models, exposed to incense smoke remained positively associated with respiratory symptoms: wheezing or whistling; breathlessness; chest tightness shortness of breath; woken up by an attack of coughing. Our study suggests that inhaled incense smoke in occupation or at home is a risk factor of lung function impairments among adult population in Saudi Arabia.

Non-intubated anaesthetic technique in open bilobectomy in a patient with severely impaired lung function

General anaesthesia has been the most commonly used method for almost all types of thoracic surgery. Recently, there has been a growing interest in non-intubated anaesthetic techniques. The rationale being, to prevent complications related to general anaesthesia and positive pressure ventilation such as barotrauma or ventilation-perfusion mismatch. We present a case with severely impaired forced expiration volume (26%), carbon monoxide diffusing capacity (26%) and VO₂max (13.9 mL/kg/min). According to current guidelines, this patient was suitable to undergo one-lung ventilation only with high risk of morbidity and mortality. Therefore, we chose the non-intubated technique for thoracotomy. Oxygenation was satisfactory throughout, the patient remained hemodynamically stable and the operation was uneventful. Oxygen supplementation was stopped from day 2 and he was discharged on day 7. To our knowledge, this is the first case report where a planned non-intubated method was applied for thoracotomy, and our results suggest that it might be a feasible and safe approach for open thoracotomy in difficult cases where severely impaired lung function indicates that one lung ventilation may carry significant risks.

Influence of Lung Function and Sleep-disordered Breathing on All-Cause Mortality. A Community-based Study

RATIONALE

Whether sleep-disordered breathing (SDB) severity and diminished lung function act synergistically to heighten the risk of adverse health outcomes remains a topic of significant debate.

OBJECTIVES

The current study sought to determine whether the association between lower lung function and mortality would be stronger in those with increasing severity of SDB in a community-based cohort of middle-aged and older adults.

METHODS

Full montage home sleep testing and spirometry data were analyzed on 6,173 participants of the Sleep Heart Health Study. Proportional hazards models were used to calculate risk for all-cause mortality, with FEV₁ and apnea-hypopnea index (AHI) as the primary exposure indicators along with several potential confounders.

MEASUREMENTS AND MAIN RESULTS

All-cause mortality rate was 26.9 per 1,000 person-years in those with SDB (AHI ≥5 events/h) and 18.2 per 1,000 person-years in those without (AHI <5 events/h). For every 200-ml decrease in FEV₁, all-cause mortality increased by 11.0% in those without SDB (hazard ratio, 1.11; 95% confidence interval, 1.08-1.13). In contrast, for every 200-ml decrease in FEV₁, all-cause mortality increased by only 6.0% in participants with SDB (hazard ratio, 1.06; 95% confidence interval, 1.04-1.09). Additionally, the incremental influence of lung function on all-cause mortality was less with increasing severity of SDB (P value for interaction between AHI and FEV₁, 0.004).

CONCLUSIONS

Lung function was associated with risk for all-cause mortality. The incremental contribution of lung function to mortality diminishes with increasing severity of SDB.

Correlation of respiratory symptoms and spirometric lung patterns in a rural community setting, Sindh, Pakistan: a cross sectional survey

BACKGROUND

Symptom-based questionnaires can be a cost effective tool enabling identification and diagnosis of patients with respiratory illnesses in resource limited setting. This study aimed to determine the correlation of respiratory symptoms and spirometric lung patterns and validity of ATS respiratory questionnaire in a rural community setting.

METHODS

This cross sectional survey was conducted between January - March 2009 on a sample of 200 adults selected from two villages of district Khairpur, Sindh, Pakistan. A modified version of the American thoracic society division of lung disease questionnaire was used to record the presence of respiratory symptoms. Predicted lung volumes i.e. forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and their ratio (FEV1/FVC) were recorded using portable spirometer.

RESULTS

In the study sample there were 91 (45.5%) males and 109 (54.5%) females with overall mean age of 34 years (±11.69). Predominant respiratory symptom was phlegm (19%) followed by cough (17.5%), wheeze (14%) and dyspnea (10.5%). Prevalence of physician diagnosed and self-reported asthma was 5.5% and 9.5% respectively. Frequency of obstructive pattern on spirometry was 28.72% and that of restrictive pattern was 19.68%. After adjustment for age, gender, socioeconomic status, spoken dialect, education, smoking status, height, weight and arsenic in drinking water, FVC was significantly reduced for phlegm (OR 3.01; 95% CI: 1.14 - 7.94), wheeze (OR 7.22; 95% CI: 2.52 - 20.67) and shortness of breath (OR 4.91; 95% CI: 1.57 - 15.36); and FEV1 was significantly reduced for cough (OR 2.69; 95% CI: 1.12 - 6.43), phlegm (OR 3.01; 95% CI: 1.26 - 7.16) and wheeze (OR 10.77; 95% CI: 3.45 - 33.6). Presence of respiratory symptoms was significantly associated with restrictive and/or obstructive patterns after controlling for confounders. Similar findings were observed through linear regression where respiratory symptoms were found to be significantly associated with decrements in lung volumes. Specificity and positive predictive values were found to be higher for all the symptoms compared to sensitivity and negative predictive values.

CONCLUSION

Symptoms based respiratory questionnaires are a valuable tool for screening of respiratory symptoms in resource poor, rural community setting.