The Effects of Hypoxia on the Immune-Modulatory Properties of Bone Marrow-Derived Mesenchymal Stromal Cells

The therapeutic repertoire for life-threatening inflammatory conditions like sepsis, graft-versus-host reactions, or colitis is very limited in current clinical practice and, together with chronic ones, like the osteoarthritis, presents growing economic burden in developed countries. This urges the development of more efficient therapeutic modalities like the mesenchymal stem cell-based approaches. Despite the encouraging in vivo data, however, clinical trials delivered ambiguous results. Since one of the typical features of inflamed tissues is decreased oxygenation, the success of cellular therapy in inflammatory pathologies seems to be affected by the impact of oxygen depletion on transplanted cells. Here, we examine our current knowledge on the effect of hypoxia on the physiology of bone marrow-derived mesenchymal stromal cells, one of the most popular tools of practical cellular therapy, in the context of their immune-modulatory capacity

Spatial Analysis of the COVID-19 Pandemic in Hungary: Changing Epidemic Waves in Time and Space

This paper examines the spatial dynamics and regional distribution of the novel coronavirus epidemic in Hungary in an effort to obtain a deeper understanding of the connection between space and health. The paper also presents comprehensive epidemiologic data on the spatiotemporal spread of the COVID-19 pandemic in terms of the epidemic waves. Following a comparison of the growth rates of infection numbers, the current study explores the geographical dimension of the three pandemic waves. The partial transformation of spatial characteristics during the three epidemic waves is among the most important results found. While geographical hotspots influenced the first wave, newly confirmed coronavirus cases in the second and third waves were due to community-based epidemic spreading. Furthermore, the western-eastern spatial relation and the core-periphery model also affected the regional distribution of new cases and deaths in the initial two waves. However, a new spatial pattern - realised by the northern-southern spatial orientation - appeared during the third wave. The outputs of this paper offer feasible suggestions for evidence-based policymaking in pandemic prevention, mitigation, and preparedness

Biológiai membránok elektromos térszerkezetének vizsgálata = Investigation of the charge structure of biological membranes

A pályázat célja a biológiai membránok fizikai tulajdonságainak vizsgálata volt, különös tekintettel a töltéseloszlás és - ezzel összefüggésben - az elektromos térszerkezet funkcionális szerepére. Modellobjektumunk a protonpumpáló bakteriorodopszin (bR) fehérjét kristályos rendben tartalmazó bíbormembrán. Kutatásainkat és a velük kapcsolatos módszertani fejlesztőmunkát három téma köré csoportosítottuk: 1. A molekulán belüli elektromos töltéseloszlás funkcionális leírása 2. A határfelületi vízréteg szerepe a fehérjék szerkezetében és működésében 3. A bR nemlineáris optikai tulajdonságainak jellemzése Eredmények: 1.Megmutattuk, hogy az általunk kifejlesztett módszer a molekula működését kísérő szerkezetváltozásokat érzékenyen jellemzi, és lehetőséget teremt az elektromos töltésátrendeződések funkcionális értelmezésére. 2.Rámutattunk, hogy a semleges sók anionjainak tulajdonított Hofmeister-effektus a fehérje-víz határfelületi réteg szerkezetváltozásaival magyarázható. Elméletünk elsőként ad teljeskörű kvalitatív leírást a 120 éves problémakörre. 3.Integrált optikai módszerekkel az eddigieknél érzékenyebben detektáltuk a bR molekulában - a lokális elektromos tér változásai következtében ? fellépő abszorpció- és törésmutató-változásokat. Megmutattuk, hogy a molekula gerjesztését követő spektrális változások alkalmasak fénykapcsolásra és -modulálásra. Az eredmények gyakorlati alkalmazása az optoelektronikában és a bioszenzorikában várható. | In the framework of the project, we investigated some physical properties of biological membranes, with special respect to the physiological role of the electric charge distribution (hence the electric field structure). Our model object was purple membrane, containing the paradigmatic proton pumping molecule bacteriorhodopsin (bR) in a quasi crystalline structure. Our research work and the related methodological developments were centered round three topics: 1.Functional description of the intra-molecular charge distribution 2.The role of interfacial water in the structure and function of proteins 3.Characterization of the nonlinear optical properties of bR Results: 1.We showed that our method represents a sensitive test for the characterization of structural changes associated to molecular function, and allows interpretation of charge rearrangements. 2.We pointed out that the Hofmeister effect, attributed to the anions of neutral salts, can be interpreted according to structural changes in the protein-water interface. Our theory gives a full-spectrum qualitative description, solving a 120-years old puzzle. 3.Using integrated optical (IO) techniques, we could sensitively characterize the nonlinear optical properties of bR films, and showed that IO light switching and modulation can be performed based on the light-induced spectral changes of bR. Practical utilization of the results is expected in optoelectronics and sensorics

Extracellular Vehicles of Oxygen-Depleted Mesenchymal Stromal Cells: Route to Off-Shelf Cellular Therapeutics?

Cellular therapy is a promising tool of human medicine to successfully treat complex and challenging pathologies such as cardiovascular diseases or chronic inflammatory conditions. Bone marrow-derived mesenchymal stromal cells (BMSCs) are in the limelight of these efforts, initially, trying to exploit their natural properties by direct transplantation. Extensive research on the therapeutic use of BMSCs shed light on a number of key aspects of BMSC physiology including the importance of oxygen in the control of BMSC phenotype. These efforts also led to a growing number of evidence indicating that the beneficial therapeutic effects of BMSCs can be mediated by BMSC-secreted agents. Further investigations revealed that BMSC-excreted extracellular vesicles could mediate the potentially therapeutic effects of BMSCs. Here, we review our current understanding of the relationship between low oxygen conditions and the effects of BMSC-secreted extracellular vesicles focusing on the possible medical relevance of this interplay

Felmérés a magyarországi Internet-használatról: betegség, vagy korosztályra jellemző tünet?

A szerzők az Internet-függőség helyzetét elemzik két hazai vizsgálat alapján. Az eredményeket elméleti síkon értelmezik és ajánlásokat fogalmaznak meg nemcsak a kóros esetek kezelésére, hanem az átlagos Internet-használók, elsősorban a fiatal generáció tagjai és környezetük számára is. Megállapítják, hogy „Internet-függőség” helyett legfeljebb csekély gyakorisággal előforduló „kóros Internet-használatról” beszélhetünk, ami nem különálló nozológiai egység, hanem egy pszichés problémahalmaz tünete, és a személyiség új típusú integrációjának lehetőségét is magában hordja. Ajánlásaik szerint a károsodottak megsegítésére virtuális klinikákat, szabadon elérhető mentálhigiénés „webkikötőket” kell létesíteni

Construction of a multipurpose photochemical reactor with on-line spectrophotometric detection

A versatile photoreactor was built for studying homogeneous and heterogeneous photochemical reactions using fiber-optic devices. The reactor was designed to allow simultaneous photochemical initiation and online spectrophotometric monitoring of the reaction using independently controlled excitation and detection lamps. The system consists of a CCD spectrophotometer, a thermostated sample holder, two light sources, and standard 1.00 × 1.00 cm (or possibly smaller) fluorescence cuvettes, all coupled with fiber optic cables. The device can be used as a photoreactor, a diode-array spectrophotometer and also as a spectrofluorimeter. The reactor can be used in flow-through operation modes. Performance tests of the instrument are reported here with a number of known photochemical systems

The pore network and the adsorption characteristics of mesoporous silica aerogel: adsorption kinetics on a timescale of seconds

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The Pore Network and the Adsorption Characteristics of Mesoporous Silica Aerogel: Adsorption Kinetics on a Timescale of Seconds

Mesoporous silica aerogel particles of ca. 5 μm in diameter can be conveniently produced by grinding in an aqueous phosphate buffer at pH 7. The pores in the suspended aerogel particles are spherical and their diameter is 18–20 nm, as measured by NMR cryoporometry. NMR diffusiometry revealed that diffusion of water is hindered inside the pores of the aerogel. In spite of steric hindrance, bulk water and pore water exchange rapidly on the millisecond timescale in the suspension, indicating a highly interconnected pore network. The adsorption of methylene blue (MB), as a model compound, was studied on the silica aerogel particles. The process was followed by on-line UV-Vis spectrophotometry after injecting the dye into the aerogel suspension. Biphasic kinetics were observed with the first process complete in ca. 80 s and the second in ca. 600 s. A detailed kinetic model was developed for the interpretation of the results. It postulates a relatively fast adsorption process with Langmuir-type kinetics, and the aggregation of aerogel particles covered by the dye on a longer timescale. The aggregates are involved in a reversible sedimentation process which actually removes MB from the suspension