Mathematical surface function-based design and 3D printing of airway stents.

BACKGROUND: Three-dimensional (3D) printing is a method applied to build a 3D object of any shape from a digital model, and it provides crucial advantages especially for transferring patient-specific designs to clinical settings. The main purpose of this study is to introduce the newly designed complex airway stent models that are created through mathematical functions and manufactured with 3D printing for implementation in real life. METHODS: A mathematical modeling software (MathMod) was used to design five different airway stents. The highly porous structures with designated scales were fabricated by utilizing a stereolithography-based 3D printing technology. The fine details in the microstructure of 3D printed parts were observed by a scanning electron microscope (SEM). The mechanical properties of airway stents with various designs and porosity were compared by compression test. RESULTS: The outputs of the mathematical modeling software were successfully converted into 3D printable files and airway stents with a porosity of more than 85% were 3D printed. SEM images revealed the layered topography of high-resolution 3D printed parts. Compression tests have shown that the mathematical function-based design offers the opportunity to adjust the mechanical strength of airway stents without changing the material or manufacturing method. CONCLUSIONS: A novel approach, which includes mathematical function-based design and 3D printing technology, is proposed in this study for the fabrication of airway stents as a promising tool for future treatments of central airway pathologies.

Evaluation of Thiol/Disulfide Homeostasis in Bronchiectasis.

PURPOSE: Thiols are sulfhydryl-containing organic compounds that have an important role in preventing cellular oxidative stress. This study compares the blood oxidative stress marker levels in bronchiectasis cases during their stable periods with healthy controls. MATERIALS AND METHODS: Seventy-seven patients (49 patients with stable bronchiectasis/28 healthy controls), followed up by the chest disease clinic, were included in the study. Peripheral blood thiol-disulfide parameters (NT: native thiol (-SH); TT: total thiol (-SH + SS); SS: disulfide (-SS); SS-SH: disulfide/native thiol index; SS-TT: disulphide/total thiol index; SH-TT: native thiol/total thiol index), and ischemia-modified albumin (IMA) levels were examined in the stable bronchiectasis group and the control group. Thiol-disulfide homeostasis was evaluated using a novel and automated assay. Findings and Result. Blood native thiol levels in patients with stable bronchiectasis were found to be significantly higher compared with healthy controls. A positive correlation between the total airway disease score and IMA levels was present. Our findings revealed that native thiol levels, which constitute a part of the antioxidant defense system, are increased in patients with stable bronchiectasis.

Incidental lung findings in coronary computed tomography angiography.

OBJECTIVE: In coronary computed tomography angiography, a part of the lung parenchyma also enters the image area which is called the field of view. The aim of this study was to evaluate the rate of pulmonary abnormalities and document their association with demographic features in subjects undergoing multislice coronary computed tomography angiography obtained for the assessment of coronary artery disease. METHODS: This was a retrospective observational study evaluating the coronary computed tomography angiography scans of 1,050 patients (58.5% males and 47.3% smokers) with a mean age of 52.2±11.2 years, obtained between January 2018 and March 2020. Pulmonary abnormalities were reported as nodules, focal consolidations, ground-glass opacities, consolidations, emphysema, cysts, bronchiectasis, atelectasis, and miscellaneous. RESULTS: In total, 274 pulmonary abnormalities were detected in 266 patients (25.3%). The distribution of incidental lung findings was as follows: pulmonary nodules: 36.4%, emphysema: 15.6%, bronchiectasis: 11%, ground-glass opacities: 7.2%, atelectasis 7.2%, focal consolidations: 5%, cysts: 6%, consolidations: 2.5%, and miscellaneous: 9.1%. The patients with pulmonary pathology were older (55.5±11.4 versus 51.0±10.9 years), and the percentage of smokers was higher (60.1 versus 43.2%). The possibility of the presence of any incidental lung findings in field of view of coronary computed tomography angiography increases significantly over the age of 40.5 years (p<0.001, AUC 0.612, 95%CI 0.573-0.651). CONCLUSION: Multislice coronary computed tomography angiography can give important clues regarding pulmonary diseases. It is essential for the reporting radiologist to review the entire scan for pulmonary pathological findings especially in patients with smoking history and over the age of 40.5 years.

Incidental lung findings in coronary computed tomography angiography

SUMMARY OBJECTIVE: In coronary computed tomography angiography, a part of the lung parenchyma also enters the image area which is called the field of view. The aim of this study was to evaluate the rate of pulmonary abnormalities and document their association with demographic features in subjects undergoing multislice coronary computed tomography angiography obtained for the assessment of coronary artery disease. METHODS: This was a retrospective observational study evaluating the coronary computed tomography angiography scans of 1,050 patients (58.5% males and 47.3% smokers) with a mean age of 52.2±11.2 years, obtained between January 2018 and March 2020. Pulmonary abnormalities were reported as nodules, focal consolidations, ground-glass opacities, consolidations, emphysema, cysts, bronchiectasis, atelectasis, and miscellaneous. RESULTS: In total, 274 pulmonary abnormalities were detected in 266 patients (25.3%). The distribution of incidental lung findings was as follows: pulmonary nodules: 36.4%, emphysema: 15.6%, bronchiectasis: 11%, ground-glass opacities: 7.2%, atelectasis 7.2%, focal consolidations: 5%, cysts: 6%, consolidations: 2.5%, and miscellaneous: 9.1%. The patients with pulmonary pathology were older (55.5±11.4 versus 51.0±10.9 years), and the percentage of smokers was higher (60.1 versus 43.2%). The possibility of the presence of any incidental lung findings in field of view of coronary computed tomography angiography increases significantly over the age of 40.5 years (p<0.001, AUC 0.612, 95%CI 0.573-0.651). CONCLUSION: Multislice coronary computed tomography angiography can give important clues regarding pulmonary diseases. It is essential for the reporting radiologist to review the entire scan for pulmonary pathological findings especially in patients with smoking history and over the age of 40.5 years.

Unclear Issues Regarding COVID-19.

Scientists from all over the world have been intensively working to discover different aspects of Coronavirus disease 2019 (COVID-19) since the first cluster of cases was reported in China. Herein, we aimed to investigate unclear issues related to transmission and pathogenesis of disease as well as accuracy of diagnostic tests and treatment modalities. A literature search on PubMed, Ovid, and EMBASE databases was conducted, and articles pertinent to identified search terms were extracted. A snow-ball search strategy was followed in order to retrieve additional relevant articles. It was reported that viral spread may occur during the asymptomatic phase of infection, and viral load was suggested to be a useful marker to assess disease severity. In contrast to immune response against viral infections, cytotoxic T lymphocytes decline in SARS-CoV-2 infection, which can be partially explained by direct invasion of T lymphocytes or apoptosis activated by SARS-CoV-2. Dysregulation of the urokinase pathway, cleavage of the SARS-CoV-2 Spike protein by FXa and FIIa, and consumption coagulopathy were the proposed mechanisms of the coagulation dysfunction in COVID-19. False-negative rates of reverse transcriptase polymerase chain reaction varied between 3% and 41% across studies. The probability of the positive test was proposed to decrease with the number of days past from symptom onset. Safety issues related to infection spread limit the use of high flow nasal oxygen (HFNO) and continuous positive airway pressure (CPAP) in hypoxic patients. Further studies are required to elucidate the challenging issues, thus enhancing the management of COVID-19 patients.

What We Learned about COVID-19 So Far? Notes from Underground.

The novel coronavirus pandemic poses a major global threat to public health. Our knowledge concerning every aspect of COVID-19 is evolving rapidly, given the increasing data from all over the world. In this narrative review, the Turkish Thoracic Society Early Career Taskforce members aimed to provide a summary on recent literature regarding epidemiology, clinical findings, diagnosis, treatment, prevention, and control of COVID-19. Studies revealed that the genetic sequence of the novel coronavirus showed significant identity to SARS-CoV and MERS-CoV. Angiotensin-converting enzyme 2 receptor is an important target of the SARS-CoV-2 while entering an organism. Smokers were more likely to develop the disease and have a higher risk for ICU admission. The mean incubation period was 6.4 days, whereas asymptomatic transmission was reported up to 25 days after infection. Fever and cough were the most common symptoms, and cardiovascular diseases and hypertension were reported to be the most common comorbidities among patients. Clinical manifestations range from asymptomatic and mild disease to severe acute respiratory distress syndrome. Several patients showed typical symptoms and radiological changes with negative RT-PCR but positive IgG and IgM antibodies. Although radiological findings may vary, bilateral, peripherally distributed, ground-glass opacities were typical of COVID-19. Poor prognosis was associated with older age, higher Sequential Organ Failure Assessment score, and high D-dimer level. Chloroquine was found to be effective in reducing viral replication in vitro. Likewise, protease inhibitors, including lopinavir/ritonavir, favipiravir, and nucleoside analogue remdesivir were proposed to be the potential drug candidates in COVID-19 management. Despite these efforts, we still have much to learn regarding the transmission, treatment, and prevention of COVID-19.

Prevalence of non-thyroidal illness syndrome in COPD exacerbation and effect of hypoxaemia and hypercapnia on thyroid functions.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease showing acute exacerbations during its course. Comorbidities often accompany. Non-thyroidal illness syndrome (NTIS) occurs because of the functional impairment in the hypothalamic-pituitary-thyroid axis in severe critical cases. The objective of the current study is to determine the prevalence of NTIS among hospitalised patients due to acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and to reveal the factors affecting thyroid functions. MATERIALS AND METHODS: A total of 132 patients hospitalised for AECOPD were enroled. Arterial blood gas samples at room air and venous blood samples for thyroid function tests were obtained within 24 hours following hospitalisation. RESULTS: The mean age was 69.3 ± 9.6 years with male predominance (M/F:130/2). The prevalence of NTIS was 55%. Subgroups of NTIS cases were analysed. Low TSH levels were the most common pathology (55%). Patients with NTIS had significantly lower PaO2 and SaO2 levels compared with those without NTIS (P = 0.045 and P = 0.022, respectively). In addition, a positive correlation was found between PaO2 and free thyroxine (fT4) (P < 0.001, r = 0.313). A statistically significant negative correlation between PaCO2 and fT4 was found (P < 0.001, r = -0.393). And a statistically significant negative correlation between PaCO2 and free triiodothyronine (fT3) values were found (P = 0.040, r = -0.183). CONCLUSION: NTIS is a very common condition during AECOPD. We believe that hypoxemia causing functional impairment in the hypothalamic-pituitary-thyroid axis is the main mechanism in NTIS development and hypercapnia disrupts freeT3 and freeT4 production and secretion.

The role of serum bilirubin levels in determining venous thromboembolism.

OBJECTIVE: Venous thromboembolism (VTE) is a disease that includes both deep venous thrombosis (DVT) and pulmonary embolism (PE). Bilirubin is an endogenous anti-inflammatory marker associated with atherothrombosis. The purpose of our study was to investigate the association of serum bilirubin levels with the presence of VTE. METHODS: A total of 103 patients with VTE (distal DVT, n = 34; proximal DVT, n = 30; PE, n = 39) and 50 control patients were cross-sectionally enrolled. Peripheral venous duplex ultrasound and computed tomography were used for the diagnosis of VTE. Fasting blood samples were drawn for biochemical analyses. RESULTS: Baseline characteristics were not different between groups. The VTE group had lower bilirubin level (9.0 ± 2.6 µmol/L vs 7.3 ± 3 µmol/L; P = .001) and higher high-sensitivity C-reactive protein (hs-CRP) concentration (0.8 [0.3-2] mg/L vs 1.1 [0.2-3] mg/L; P = .008) and white blood cell count (7.4 ± 1.5 × 109/L vs 8.2 ± 2.7 × 109/L; P = .02) compared with control patients. In the analysis of variance, the levels of total direct bilirubin and hs-CRP were clearly different between the control group and VTE subgroups (distal and proximal DVT and PE). The receiver operating characteristic curve analysis showed a cutoff value of 8.9 µmol/L for total bilirubin (sensitivity, 74%; specificity, 55%) and an area under the curve of 0.659 (P < .001). CONCLUSIONS: Bilirubin level, hs-CRP concentration, and white blood cell count were independently associated with VTE.

Factors Affecting Influenza Vaccination Rates among Patients with Chronic Obstructive Pulmonary Disease in Rize, Turkey.

OBJECTIVES: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are major components of COPD-related socioeconomic burden. Upper or lower respiratory tract infections, usually caused by respiratory viruses or bacteria, are common causes of AECOPD. Vaccination aganist influenza virus and Streptoccus pneumoniae, the most prevalent agents, is recommended by COPD guidelines. The aims of this study were to determine the factors affecting vaccination among patients with COPD and to assess the effect of vaccination status on AECOPD. MATERIALS AND METHODS: Patients with COPD were recruited from the outpatient clinic of a tertiary hospital between December 2014 and January 2015. Demographic data, vaccination status, and COPD-related hospital admissions triggered by tracheobronchial infections were evaluated. RESULTS: In total, 108 patients were enrolled; 102 (94%) subjects were male, and 6 (6%) subjects were female; the mean age was 65.6 years. The number of patients who had received pneumococcal and influenza vaccinations were 8 (0.07%) and 36 (33.3%), respectively. There was no significant correlation between the level of education and vaccination status. No significant difference was found between two groups in terms of exacerbation frequency, hospitalization rates, mMRC scores, and COPD stages. CONCLUSION: More efforts by both physicians and patients are needed to reach the ideal rates of vaccination for COPD.