Impact of COVID-19 on different business models of European airlines

In addition to social damage, the first wave of the COVID-19 pandemic also caused huge economic losses in the beginning of 2020, especially for companies in the tourism sector. The airline market was no exception. This study examines the significance of the business model of European listed airlines – low cost carriers (LCCs), full service carriers (FSCs) – for stock market performance. We use event study on the 11 airlines included in the sample. In terms of cumulative average abnormal returns, i.e. the most significant deviations from expected returns, negative phases can be detected in the entire and third stage of the pandemic. FSCs performed significantly better than LCCs at the time of the pandemic on 24 February, when European stock markets suffered the most damage; the business model overwrote financial indicators during the toughest period of the crisis. Although most LCCs had higher cash/ assets ratios, they still produced worse results than the average performance of companies with lower cash/assets ratios. This analysis helps to ensure that, in addition to examining financial indicators, the enumeration of the business model in this industry can also be decisive. The future possibilities of the research are discussed at the end of the study

PPARγ is a gatekeeper for extracellular matrix and vascular cell homeostasis: beneficial role in pulmonary hypertension and renal/cardiac/pulmonary fibrosis.

PURPOSE OF REVIEW: Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial endothelial cell (PAEC) dysfunction and apoptosis, pulmonary arterial smooth muscle cell (PASMC) proliferation, inflammation, vasoconstriction, and metabolic disturbances that include disrupted bone morphogenetic protein receptor (BMPR2)-peroxisome proliferator-activated receptor gamma (PPARγ) axis and DNA damage. Activation of PPARγ improves many of these mechanisms, although erroneous reports on potential adverse effects of thiazolidinedione (TZD)-class PPARγ agonists reduced their clinical use in the past decade. Here, we review recent findings in heart, lung, and kidney research related to the pathobiology of vascular remodeling and tissue fibrosis, and also potential therapeutic effects of the PPARγ agonist pioglitazone. RECENT FINDINGS: Independent of its metabolic effects (improved insulin sensitivity and fatty acid handling), PPARγ activation rescues BMPR2 dysfunction, inhibits TGFβ/Smad3/CTGF and TGFβ/pSTAT3/pFoxO1 pathways, and induces the PPARγ/apoE axis, inhibiting vascular remodeling. PPARγ activation dampens mtDNA damage via PPARγ/UBR5/ATM pathway, improves function of endothelial progenitor cells (EPCs), and decrease renal fibrosis by repressing TGFβ/pSTAT3 and TGFβ/EGR1. SUMMARY: Pharmacological PPARγ activation improves many hallmarks of PAH, including dysfunction of BMPR2-PPARγ axis, PAEC, PASMC, EPC, mitochondria/metabolism, and inflammation. Recent randomized controlled trials, including IRIS (Insulin Resistance Intervention After Stroke Trial), emphasize the beneficial effects of PPARγ agonists in PAH patients, leading to recent revival for clinical use

Vese ischemia/reperfúziós károsodásának gátlása RNS interferencia segítségével = RNA interference (RNAi) to limit kidney ischemia/reperfusion injury.

Az RNS interferencia a génterápia új, ígéretes területe. Korábbi kísérleteink során elsőként alkalmaztuk ezt az új technológiát a vese ischemia-reperfúzós károsodásának gátlására (Hamar: PNAS, 2004, US.Apps - 20080227733). Az intenzív osztályon bekövetkezett haláleset kb. 30%-a a vese oxigénhiányos károsodásának következménye. Az oxigénhiányos állapotban elszenvedett szövetkárosodást kiterjedésében, súlyosságában meghaladhatja a véráramlás újbóli megindulását követő reperfúziós károsodás. A reperfúziós során keletkező oxigén szabadgyökök következtében súlyos oxidatív stressz okoz károsodást, és a sejtek programozott sejthalál (apoptózis) útján pusztulnak el. Ezért kísérleteink célja a vese reperfúziós károsodásának csökkentése. A FAS apoptózis receptor termelődését gátoló kezelésünk javította a veseműködést és a túlélést. A szabadgyök-termelő enzim kaszkád első elemét a NADPH-oxidáz (NOX-2,4) enzim termelődését gátló siRNS sejtkultúrában és egér-modellen javította a túlélést, a vese-működést. Kísérleteink során továbbá vizsgáljuk, az siRNS bejuttatásának leghatékonyabb módját, és az esetleges mellékhatásokat is. Eredményeinket két közleményben foglaltuk össze. A célszervbe-sejtbe történő bejuttatás hatékonyságának növelésében, sejt-specifikus célzott bevitel kifejlesztésében segítségünkre van Judy Liebermannal (Harvard Medical School, Boston, USA) akivel együttműködésben fejlesztettük ki az RNS interferencia alkalmazását egér máj és vese betegségek kezelésére. | RNA interference is a new, promising field of gene-therapy. We were the first, to apply this technique to inhibit reperfusion injury of the kidney (Hamar: PNAS, 2004, US.Apps - 20080227733). Renal oxygen depletion is a leading cause of death at the Intensive Care Units (ICU). Reperfusion injury following reconstitution of blood supply may substantially exceed the damage due to oxygen deficiency (ischemic injury). Oxygen radicals, produced during reperfusion induce a severe oxidative stress, and cells are lost through programmed cell death (apoptosis). Thus, our aim is to reduce reperfusion injury of the kidney. Inhibition of FAS apoptosis receptor improved renal function and survival. Inhibition of NADPH-oxidase (NOX-2,4) - the first enzyme of the oxidative radical producing enzyme cascade improved renal function, and cell survival in cell culture and mouse model. We summarized our data in 2 publications. Furthermore, we investigate the most effective way of targeting the siRNA in the right cell, and possible side-effects of siRNA in collaboration with Judy Liebermann (Harvard Medical School, Boston, USA), with whom we have developed application of RNA interference in mice for renal and liver diseases

Cinaciguat ameliorates glomerular damage by reducing ERK1/2 activity and TGF-ß expression in type-1 diabetic rats

Abstract Decreased soluble guanylate cyclase activity and cGMP levels in diabetic kidneys were shown to influence the progression of nephropathy. The regulatory effects of soluble guanylate cyclase activators on renal signaling pathways are still unknown, we therefore investigated the renal molecular effects of the soluble guanylate cyclase activator cinaciguat in type-1 diabetic (T1DM) rats. Male adult Sprague-Dawley rats were divided into 2 groups after induction of T1DM with 60 mg/kg streptozotocin: DM, untreated (DM, n = 8) and 2) DM + cinaciguat (10 mg/kg per os daily, DM-Cin, n = 8). Non-diabetic untreated and cinaciguat treated rats served as controls (Co (n = 10) and Co-Cin (n = 10), respectively). Rats were treated for eight weeks, when renal functional and molecular analyses were performed. Cinaciguat attenuated the diabetes induced proteinuria, glomerulosclerosis and renal collagen-IV expression accompanied by 50% reduction of TIMP-1 expression. Cinaciguat treatment restored the glomerular cGMP content and soluble guanylate cyclase expression, and ameliorated the glomerular apoptosis (TUNEL positive cell number) and podocyte injury. These effects were accompanied by significantly reduced TGF-ß overexpression and ERK1/2 phosphorylation in cinaciguat treated diabetic kidneys. We conclude that the soluble guanylate cyclase activator cinaciguat ameliorated diabetes induced glomerular damage, apoptosis, podocyte injury and TIMP-1 overexpression by suppressing TGF-ß and ERK1/2 signaling

A juxtaglomeruláris apparátus parakrin szabélyozása: Funkcionális és morfológiai összefüggések normál és kóros körülmények között = Paracrine Control of the Juxtaglomerular Apparatus: Functional and Morphological Correlations in Health and Disease

Speciális technika kifejlesztésével és a két foton lézermikroszkóp segítségével elsőként tettük láthatóvá in vivo a patkány vese afferens arteriola disztális szakaszán található endotheliális fenesztrációt. Kimértük a fenesztrált terület nagyságát és bizonyítottuk annak életkortól, illetve a szervezet aktuális állapotától függő változását. Real time formában nyomon követtük a renin granulumok ezen keresztüli keringésbe jutását. Igazoltuk, hogy a filtráció már a glomerulust megelőző disztális afferens arteriola szakaszban megkezdődik. Vizualizáltuk a juxtaglomeruláris apparátus intersticiális folyadék mozgását és kimutattuk, hogy a juxtaglomeruláris apparátusba folyadék filtrálódik az afferens arteriolából, a mesangiumon keresztül a glomerulusból, illetve a glomerulusból a macula densan keresztül a disztális tubulusba. Ezek az eredmények alapvetően megkérdőjelezik a juxtaglomeruláris apparátus működésére és jelentőségére vonatkozó eddigi elképzeléseinket. A fenesztráció kialakulását, illetve a hozzátartozó nanocsatornák morfológiáját atomerőmikroszkópiával analizáltuk sejttenyészetben. Az angiotenzin II és a vaszkuláris endotheliális növekedési faktor (VEGF) fokozta a fenesztrumok képződését az AT1, illetve a VEGFR-2 receptoron keresztül. E folyamat függ a p38 aktiválódásától. A fenesztráció fokozódása együtt járt a 40kD-os dextran áteresztőképesség növekedésével és a sejtréteg elektromos impedancia csökkenésével. | With a special technical development and the use of two photon laser microscopy, for the first time, in vivo, we managed to visualize the endothelial fenestration at the distal section of the afferent arteriole in rat kidney. The area of the fenestrated section was measured and its change depending on age and actual condition was demonstrated. The passage of the renin granules into the circulation via these fenestrations were followed in real time. We documented that filtration already starts at the distal part of the afferent arteriole before glomerulus. The interstitial fluid movement in the juxtaglomerular apparatus was visualized. It was also shown that in JGA, fluid is filtered via afferent arteriole, mesangium, glomerulus and macula densa into the distal tubule. These findings basically question our understanding about the function and importance of JGA. The development of fenestration and the morphology of the related nanochannels were analyzed in the cell culture with the help of AFM. Angiotensin II and Vascular Endothelial Growth Factor (VEGF) increased fenestrates via AT1 and VEGFR-2 receptors. This process is p38 dependent. Increase in fenestration was accompanied by increase in permeability to 40kD dextran and decrease in cell layer electrical impedance

Simple, readily available clinical indices predict early and late mortality among patients with ANCA-associated vasculitis

BACKGROUND: The early identification of patients with ANCA-associated vasculitis (AAV) who are at increased risk for inferior clinical outcome at the time of diagnosis might help to optimize the immunosuppressive therapy. In this study we wanted to determine the predictive value of simple clinical characteristics, which may be applicable for early risk-stratification of patients with AAV. METHODS: We retrospectively analyzed the outcome of 101 consecutive patients with AAV receiving a protocolized immunosuppressive therapy. Baseline Birmingham Vasculitis Activity Score (BVAS) and non-vasculitic comorbidities were computed, then predictors of early (90 days) mortality, infectious death, relapse and end stage kidney disease (ESKD) were evaluated. RESULTS: The baseline comorbidity score independently predicted early mortality (HR 1.622, CI 1.006-2.614), and showed association with infectious mortality (HR 2.056, CI 1.247-3.392). Patients with BVAS at or above median (=21) had worse early mortality in univariable analysis (HR 3.57, CI 1.039-12.243) (p = 0.031), and had more frequent relapses (p = 0.01) compared to patients with BVAS below median. CONCLUSIONS: Assessing baseline comorbidities, beside clinical indices characterizing the severity and extension of AAV, might help clinicians in risk-stratification of patients. Future prospective studies are needed to investigate whether therapies based on risk-stratification could improve both short term and long term survival

Pharmacological preconditioning with gemfibrozil preserves cardiac function after heart transplantation

While heart transplantation (HTX) is the definitive therapy of heart failure, donor shortage is emerging. Pharmacological activation of soluble guanylate cyclase (sGC) and increased cGMP-signalling have been reported to have cardioprotective properties. Gemfibrozil has recently been shown to exert sGC activating effects in vitro. We aimed to investigate whether pharmacological preconditioning of donor hearts with gemfibrozil could protect against ischemia/reperfusion injury and preserve myocardial function in a heterotopic rat HTX model. Donor Lewis rats received p.o. gemfibrozil (150 mg/kg body weight) or vehicle for 2 days. The hearts were explanted, stored for 1 h in cold preservation solution, and heterotopically transplanted. 1 h after starting reperfusion, left ventricular (LV) pressure-volume relations and coronary blood flow (CBF) were assessed to evaluate early post-transplant graft function. After 1 h reperfusion, LV contractility, active relaxation and CBF were significantly (p < 0.05) improved in the gemfibrozil pretreated hearts compared to that of controls. Additionally, gemfibrozil treatment reduced nitro-oxidative stress and apoptosis, and improved cGMP-signalling in HTX. Pharmacological preconditioning with gemfibrozil reduces ischemia/reperfusion injury and preserves graft function in a rat HTX model, which could be the consequence of enhanced myocardial cGMP-signalling. Gemfibrozil might represent a useful tool for cardioprotection in the clinical setting of HTX surgery soon