Extracellular vesicles: Their emerging roles in the pathogenesis of respiratory diseases

Alveoli are the basic structure of the lungs, consisting of various types of parenchymal and bone marrow-derived cells including alveolar macrophages. These various types of cells have several important functions; thus, communication between these cells plays an important role in homeostasis as well as in the pathophysiology of diseases in the lungs. For a better understanding of the pathophysiology of lung diseases, researchers have isolated each type of lung cell to investigate the changes in their gene expressions, including their humoral factor or adhesion molecules, to reveal the intercellular communication among these cells. In particular, investigations during the past decade have focused on extracellular vesicles, which are lipid bilayer delimited vesicles released from a cell that can move among various cells and transfer substances, including microRNAs, mRNAs and proteins, thus, functioning as intercellular messengers. Extracellular vesicles can be classified into three general groups: apoptotic bodies, exosomes, and microparticles. Extracellular vesicles, especially exosomes and microparticles, are attracting increasing attention from pulmonologists as tools for understanding pathogenesis and disease diagnosis. Here, we review studies, including our own, on exosomes and microparticles and their roles in both lung homeostasis and the pathogenesis of lung diseases such as idiopathic pulmonary fibrosis, chronic obstructive lung diseases, and acute respiratory distress syndrome. This review also addresses the roles of extracellular vesicles in COVID-19, the current global public health crisis.     

COVID-19 as a trigger of irritable bowel syndrome: A review of potential mechanisms

In December 2019 a novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), started spreading from Wuhan city of Chinese Hubei province and rapidly became a global pandemic. Clinical symptoms of the disease range from paucisymptomatic disease to a much more severe disease. Typical symptoms of the initial phase include fever and cough, with possible progression to acute respiratory distress syndrome. Gastrointestinal manifestations such as diarrhoea, vomiting and abdominal pain are reported in a considerable number of affected individuals and may be due to the SARS-CoV-2 tropism for the peptidase angiotensin receptor 2. The intestinal homeostasis and microenvironment appear to play a major role in the pathogenesis of COVID-19 and in the enhancement of the systemic inflammatory responses. Long-term consequences of COVID-19 include respiratory disturbances and other disabling manifestations, such as fatigue and psychological impairment. To date, there is a paucity of data on the gastrointestinal sequelae of SARS-CoV-2 infection. Since COVID-19 can directly or indirectly affect the gut physiology in different ways, it is plausible that functional bowel diseases may occur after the recovery because of potential pathophysiological alterations (dysbiosis, disruption of the intestinal barrier, mucosal microinflammation, post-infectious states, immune dysregulation and psychological stress). In this review we speculate that COVID-19 can trigger irritable bowel syndrome and we discuss the potential mechanisms.     

Synthetic MRI is not yet ready for morphologic and functional assessment of patellar cartilage at 1.5 Tesla

PurposeThe purpose of this study was to compare morphologic assessment and relaxometry of patellar hyaline cartilage between conventional sequences (fast spin-echo [FSE] T2-weighted fat-saturated and T2-mapping) and synthetic T2 short-TI inversion recovery (STIR) and T2 maps at 1.5 T magnetic resonance imaging (MRI).MethodThe MRI examinations of the knee obtained at 1.5 T in 49 consecutive patients were retrospectively studied. There were 21 men and 28 women with a mean age of 45 ± 17.7 (SD) years (range: 18–88 years). Conventional and synthetic acquisitions were performed, including T2-weighted fat-saturated and T2-mapping sequences. Two radiologists independently compared patellar cartilage T2-relaxation time on conventional T2-mapping and synthetic T2-mapping images. A third radiologist evaluated the patellar cartilage morphology on conventional and synthetic T2-weighted images. The presence of artifacts was also assessed. Interobserver agreement for quantitative variables was assessed using intraclass correlation coefficient (ICC).ResultsIn vitro, conventional and synthetic T2 maps yielded similar mean T2 values 58.5 ± 2.3 (SD) ms and 58.8 ± 2.6 (SD) ms, respectively (P = 0.414) and 6% lower than the expected experimental values (P = 0.038). Synthetic images allowed for a 15% reduction in examination time compared to conventional images. On conventional sequences, patellar chondropathy was identified in 35 patients (35/49; 71%) with a mean chondropathy grade of 4.8 ± 4.8 (SD). On synthetic images, 28 patients (28/49; 57%) were diagnosed with patellar chondropathy, with a significant 14% difference (P = 0.009) and lower chondropathy scores (3.7 ± 4.9 [SD]) compared to conventional images. Motion artifacts were more frequently observed on synthetic images (18%) than on conventional ones (6%). The interobserver agreement was excellent for both conventional and synthetic T2 maps (ICC > 0.83). Mean cartilage T2 values were significantly greater on synthetic images (36.2 ± 3.8 [SD] ms; range: 29-46 ms) relative to conventional T2 maps (31.8 ± 4.1 [SD] ms; range: 26-49 ms) (P < 0.0001).ConclusionDespite a decrease in examination duration, synthetic images convey lower diagnostic performance for chondropathy, greater prevalence of motion artifacts, and an overestimation of T2 values compared to conventional MRI sequences.     

Nanotherapeutic approach to treat diabetic foot ulcers using tissue-engineered nanofiber skin substitutes: A review

Background and aimsDiabetes mellitus (DM) is a chronic metabolic disease associated with long-term multisystem complications, among which nonhealing diabetic foot ulcers (DFUs) are recognized as major cause of morbidity and mortality. Treating DFUs with surgical procedures such as synthetic or biological skin grafts or skin substitutes has several limitations, where none of the currently available skin substitutes is ideal.MethodsOVID/Medline and PubMed databases were searched using the Medical Subject Heading (MeSH) or Title/Abstract words (“diabetic foot ulcers”, “skin substitutes”, and “nanofibers”), to identify published research studies on DFUs and nanofibers.ResultsElectrospinning nanotechnology is being used in the biomedical field to produce polymeric nanofibers impregnated with drugs for wound healing, burns and diabetic ulcers. Those nanofibers also enable seeding of cells into them and culturing them in vitro to synthesize tissue-like structures. Knowing the advantages of generating patient-specific induced pluripotent stem cells (iPSCs) and organoids in three-dimension (3D), including skin organoids, it is worth mingling these technologies to develop tissue-engineered biological skin substitutes.ConclusionNanofiber-skin substitutes hold promise for treatment of patients suffering from DFUs and inspire novel strategies that could be applied to other organ systems as well, introducing a new era of “regenerative and personalized medicine”.     

The effect of education given to type 2 diabetic individuals on diabetes self-management and self-efficacy: Randomized controlled trial

AimThis study used a randomized controlled trial design and was carried out to examine the effect of education on diabetes self-management and self-efficacy in patients with type 2 diabetes.MethodsThe study was carried out between July 2016–March 2017. Data were collected using information form, Diabetes Self-Management Questionnaire (DSMQ), self-efficacy scale for patients with type 2 diabetes (DSS).The individuals in the experimental group were given education. Both groups were reminded about the control time of their metabolic values on the phone in the 3rd and 6th months.ResultsThe average age of the individuals was 59.91 ± 8.93 (n = 78), 62.8% (n = 49) were female, 92.3% (n = 72), were married, 42.3% (n = 33) were high school graduates and their diabetes duration was 7.05 ± 3.9. There was a statistically significant difference in the 6th month metabolic values in the experimental group compared to the control group. When diabetes self-management and self-efficacy were examined, a statistically significant difference was found in the experimental group compared to the control group at 3rd and 6th months (p < 0.05, p < 0.01).ConclusionIn this study, a significant increase in diabetes self-management and self-efficacy and a significant decrease in metabolic values were observed as a result of education and phone reminders given to individuals with type 2 diabetes.