Lung function in smokers - Aspects on COPD diagnosis and associations to atherosclerosis and alcohol consumption

Smoking is the most common and important risk factor for reduced lung function. Chronic Obstructive Pulmonary Disease (COPD) affects mainly smokers and is characterized by airflow obstruction, assessed using one of two major diagnostic spirometric criteria. Aspects of lung function besides spirometry in smokers fulfilling none, either or both of the spirometric criteria for COPD are not well known. Early COPD is hard to reveal, as spirometry has a poor relationship to symptoms. A promising method for early diagnosis of COPD is Impulse Oscillometry System (IOS). Reduced lung function (measured with spirometry) and COPD is associated with cardiovascular disease in a not completely understood way. Smoking is associated with elevated alcohol consumption, but the potential association between lung function and alcohol consumption is unclear. The aim of this thesis was to analyse extensive lung function tests in a population withmany smokers with light or no decrease in lung function with special reference to COPD diagnosis and association to atherosclerosis and alcohol consumption. From a previous population-based respiratory questionnaire survey 450 subjects were recruited (never-smokers and smokers, with/without self-reported COPD) and examined with spirometry, body plethysmography, diffusing capacity for CO (DL,CO), IOS and ultrasonography of the internal carotid artery. They also answered questionnaires and blood samples were collected. The results show differences in DL,CO, residual volume and respiratory symptoms between subjects fulfilling none, either or both of the diagnostic spirometric criteria for COPD in use. (paper I). Pulmonary resistance is higher in symptomatic subjects, irrespective of a spirometric COPD diagnosis or not (paper II). Subjects with atherosclerotic plaques in the ICA have lower DL,CO and higher residual volume than subjects without plaques(paper III). Among smokers, heavy drinking is associated with lower DL,CO and forced expiratory volume in one second (FEV1) (paper IV). In conclusion, this thesis shows that other aspects of lung function in smokers than FEV1 are of value in both COPD diagnosis and in understanding associations to atherosclerosis and alcohol consumption

Applications of Artificial Intelligence in PSMA PET/CT for Prostate Cancer Imaging

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has emerged as an important imaging technique for prostate cancer. The use of PSMA PET/CT is rapidly increasing, while the number of nuclear medicine physicians and radiologists to interpret these scans is limited. Additionally, there is variability in interpretation among readers. Artificial intelligence techniques, including traditional machine learning and deep learning algorithms, are being used to address these challenges and provide additional insights from the images. The aim of this scoping review was to summarize the available research on the development and applications of AI in PSMA PET/CT for prostate cancer imaging. A systematic literature search was performed in PubMed, Embase and Cinahl according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 26 publications were included in the synthesis. The included studies focus on different aspects of artificial intelligence in PSMA PET/CT, including detection of primary tumor, local recurrence and metastatic lesions, lesion classification, tumor quantification and prediction/prognostication. Several studies show similar performances of artificial intelligence algorithms compared to human interpretation. Few artificial intelligence tools are approved for use in clinical practice. Major limitations include the lack of external validation and prospective design. Demonstrating the clinical impact and utility of artificial intelligence tools is crucial for their adoption in healthcare settings. To take the next step towards a clinically valuable artificial intelligence tool that provides quantitative data, independent validation studies are needed across institutions and equipment to ensure robustness

Area of ischemia assessed by physicians and software packages from myocardial perfusion scintigrams.

The European Society of Cardiology recommends that patients with >10% area of ischemia should receive revascularization. We investigated inter-observer variability for the extent of ischemic defects reported by different physicians and by different software tools, and if inter-observer variability was reduced when the physicians were provided with a computerized suggestion of the defects

Ovarian Transcriptomics of D. melanogaster Reveal Candidate Genes Underlying Wolbachia-Associated Plastic Recombination

Phenotypic plasticity is prevalent in nature, and its study facilitates understanding of how organisms acclimate to stressful environments. Recombination rate is plastic in a diversity of organisms and under a variety of stressful conditions. However, the recent finding that Wolbachia pipientis induces plastic recombination in Drosophila melanogaster deviates from previous patterns, because Wolbachia is not strictly considered a stressor to this host. We investigate the molecular mechanisms of Wolbachia-associated plastic recombination by comparing the ovarian transcriptomes of D. melanogaster infected and uninfected with Wolbachia. Our data suggest infection explains a small amount of transcriptional variation but specifically affects genes related to cell cycle, translation, and metabolism. We also find enrichment of cell division and recombination processes. Broadly, the transcriptomic changes identified in this study provide insight for the mechanisms of microbe-mediated plastic recombination, an important but poorly understood facet of host-microbe dynamics

Socioeconomic circumstances and incidence of chronic obstructive pulmonary disease (COPD) in an urban population in Sweden

The association between socioeconomic circumstances and incidence of chronic obstructive pulmonary disease (COPD) was investigated in an urban population in Sweden. The study included all 40–89 year-old inhabitants in Malmö, Sweden (N = 117,479) without previous hospitalization due to COPD, who were followed over 14 years for COPD related hospital admissions. The Malmö Preventive Project (MPP) cohort (n = 27,358) with information on biological and lifestyle factors was also used to study the association between socioeconomic circumstances and COPD. The Swedish hospital discharge register was used to record incidence of COPD hospitalizations. A total of 2,877 individuals (47.5% men) were discharged from hospital with COPD as the primary diagnosis during follow-up in Malmö. Low annual income (hazard ratio (HR): 2.23; 95%CI: 1.97–2.53, P < 0.001) and rented (vs. self-owned) housing (HR: 1.41; 1.30–1.52, P < 0.001) were associated with a higher risk for COPD. In addition, compared to married subjects, divorced (HR: 1.61; 1.46–1.78, P < 0.001) and widowed (HR: 1.30; 1.16–1.46, P < 0.001) individuals had an increased risk for hospitalization due to COPD. Low income, low occupation and being divorced or widowed were similarly associated with COPD in the MPP cohort, after adjustments for smoking, FEV 1 , BMI, age and sex. However, socioeconomic circumstances were not associated with COPD in analyses restricted to never smokers. Low socioeconomic circumstances were associated with an increased risk of COPD after adjustments for biological and lifestyle risk factors including smoking status. However, this relationship was not significant in those who never smoked

Evaluation of 18F-FDG uptake in lung parenchyma compensating for tissue fraction : Comparison between non-enhanced low dose CT and intravenous contrast-enhanced diagnostic CT

AIM: To determine how the presence of intravenous (IV) contrast-enhanced CT influences SUV measurements corrected for both attenuation and tissue fraction. MATERIAL AND METHODS: Eighteen patients with different malignancies, free from lung disorders, lung cancer or metastasis, were prospectively recruited when referred for staging with combined 18F-FDG-PET/CT examination. A non-enhanced low-dose CT over the chest was immediately followed by a whole-body IV contrast-enhanced diagnostic CT and finally the PET acquisition. PET data were reconstructed with attenuation correction based on the two CT data sets. The lungs were segmented in the CT images and lung density was measured. Uptake of 18F-FDG in lung parenchyma was recorded using both non-enhanced and IV contrast-enhanced CT as well as with and without compensation for lung aeration. A comparison of SUV values of corrected and uncorrected PET images was performed. RESULTS: There was no significant difference between low dose PET/CT and IV contrast-enhanced PET/CT when removing the impact of air fraction (p = 0.093 for the right lung and p = 0.085 for the left lung). When tissue fraction was not corrected for, there was a significant difference between low dose PET/CT and IV contrast enhanced PET/CT used for attenuation correction (p = 0.006 for the right lung and p = 0.015 for the left lung). CONCLUSION: There was only a marginal effect on the assessement of SUV in the lung tissue when using IV contrast enhanced CT for attenuation correction when the air fraction was accounted for

Associations between lung function and alcohol consumption - Assessed by both a questionnaire and a blood marker.

Studies on the influence of alcohol consumption on lung function have shown conflicting results. Self-reported alcohol consumption may be inaccurate. This study used both a validated alcohol questionnaire and a blood marker of heavy alcohol consumption, and examined potential associations with different lung physiological variables

Common physiologic and proteomic biomarkers in pulmonary and coronary artery disease

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) and coronary artery disease (CAD) are leading causes of global morbidity and mortality. There is a well-known comorbidity between COPD and CAD, which is only partly explained by smoking and other known common risk factors. In order to better understand the relationship between COPD and CAD, we analyzed myocardial perfusion, pulmonary function and novel cardiovascular biomarkers in patients with symptoms suggesting myocardial ischemia.METHODS: A total of 396 subjects from the Swedish Biomarkers and Genetics CardioPulmonary Physiology Study (BiG CaPPS) were included, all of whom had been referred to myocardial perfusion imaging due to suspected myocardial ischemia. Subjects performed myocardial perfusion imaging (MPI), pulmonary function tests (PFT) and analysis of 92 proteomic biomarkers, previously associated with cardiovascular disease. Linear regression was used to study the relationship between MPI and PFT results and proteomic biomarkers.RESULTS: Subjects with CAD (n = 159) had lower diffusing capacity (DLCO) than patients without CAD (6.64 versus 7.17 mmol/(min*kPa*l); p = 0.004) in models adjusted for common covariates such as smoking, but also diabetes and brain natriuretic peptide (BNP). The association remained significant after additional adjustment for forced expiratory volume in one second (FEV1) (p = 0.009). Subjects with CAD, compared with subjects without CAD, had higher total airway resistance (0.37 vs 0.36 kPa/(l/s); p = 0.036). Among 92 protein biomarkers, nine were associated with a combined diagnosis of CAD and airflow obstruction: VSIG2, KIM1, FGF-23, REN, XCL1, GIF, ADM, TRAIL-R2 and PRSS8.SIGNIFICANCE: Diffusing capacity for carbon monoxide is decreased in patients with CAD, independently of decreased FEV1, diabetes, and elevated BNP. Several cardiovascular biomarkers are associated with co-existent CAD and airflow obstruction, but none with airflow obstruction only. The current findings indicate that the interaction between CAD and lung function is complex, including mechanisms beyond the known association between CAD and reduced ventilation

Inhomogeneity of ventilation in smokers and mild COPD assessed by the ratio of alveolar volume to total lung capacity

Background: Previous studies have shown that the ratio between alveolar volume (VA) and total lung capacity (TLC) reflects ventilation heterogeneity in subjects with chronic obstructive pulmonary disease (COPD). However, the ratio and its correlation to respiratory symptoms had to our knowledge not previously been investigated in subjects with mild chronic airflow obstruction or without airflow obstruction (normal ratio FEV1/VC). The purpose of this study was to investigate potential connection between VA/TLC and respiratory symptoms, smoking habits and lung function parameters in subjects with normal spirometry and with mild chronic airflow obstruction Methods: We examined 450 subjects (82 non-smokers with normal spirometry, 298 subjects who smoked or had smoked earlier but had a normal spirometry and 70 subjects with chronical airflow obstruction) with routine lung function tests and a questionnaire regarding respiratory symptoms Results: This study showed 31 out of 54 subjects with a low VA/TLC had a normal ratio FEV1/VC. Of these subjects, 58.1 % had respiratory symptoms, compared to the group with normal ratio for both VA/TLC and FEV1/VC where 35.8 % had respiratory symptoms (p-value 0.02). Conclusion: This study has shown that within the group of subjects with a normal ratio FEV1/VC, those with a decreased ratio VA/TLC had a higher prevalence of respiratory symptoms compared to subjects with a normal VA/TLC ratio. These findings indicate that including the ratio VA/TLC in the evaluation of a pulmonary function test assessment might increase the possibility to identify subjects with early or at risk of lung disease

Fixed ratio or lower limit of normal for the FEV1 /VC ratio: relation to symptoms and extended lung function tests.

There is no general agreement on the spirometric definition of chronic obstructive pulmonary disease (COPD). The global initiative for obstructive lung disease recommends a fixed ratio between forced expiratory volume in one-second (FEV1 ) and forced vital capacity (FVC) of 0·7