Nature conservation oriented algal biodiversity monitoring investigations in the main arm and some dead arms of the River Tisza I. Benthic diatoms

Benthic diatoms started to be studied as part of the Hungarian National Biodiversity Monitoring Programme in some dead-arms within the Pilot Project area in 1996 and continued in 2000-2001. The investigations had a nature conservation oriented biodiversity monitoring focus but besides the diversity of diatom communities, the water quality of the dead-arms was also described on the basis of benthic diatom species composition an relative abundance by using the trophic and saprobic condition scale of Hofmann. A considerable nutrient content was detected in the investigated dead-arms; besides algal blooms and the spreading of macrophytes, benthic diatom investigations always supported this fact. On the basis of a German red list several valuable species were found in the studied dead-arm. This valuable algal flora can only be protected by the conservation of the habitats (dead-arms) and its catchments area

A spinalis izomatrophia személyre szabott terápiás lehetőségei

Spinal muscular atrophy (SMA) is an autosomal recessive disease leading to progressive muscle weakness and atrophy, in severe cases also affecting the bulbar and respiratory muscles.The clinical spectrum of the disease is extremely variable, in the most severe cases resulting in perinatal death, while at the least severe end of the spectrum causing some motor deficits in old age without the loss of ambulation. Spinal muscular atrophy care has changed dramatically in recent years due to the availability of new therapeutic options. The FDA approved nusinersen in 2016, this was followed by the approval of onasemnogene abeparvovec in 2019 and risdiplam in 2020. The EMA approved all three therapies a year later. Two of the threapies work at the pre-mRNA level, one at the DNA level. The clinical studies leading to the approval of the three drugs included patients of different ages and clinical conditions, and utilised partly different motor and functional scales. Therefore, direct comparison of these clinical studies is not possible. However, an increasing amount of real-world data contribute to the better understanding of the efficacy of the different therapies for patients of different ages and clinical conditions, in a real-world setting. Thus, the question may arise “Which is the best SMA therapy?”. This is an impossible question to answer. Indeed the question “Which therapy is the most suitable for a certain patient at a certain time?” is much more realistic. Here, we provide a brief overview of the objectively measurable results of the three therapies to date and an outlook into future therapeutic avenues

Magyarország Centrales fajainak florisztikai felmérése összefüggésben a természetvédelemmel = Floristical studies on centric diatoms in Hungary concerning the nature conservation

A pályázat során Magyarország keleti területén közel 200 álló- és folyóvízből több mint 300 mintát vizsgáltunk, valamint vízkémiai változókat is mértünk mind a helyszínen, mind a laboratóriumban. A mintákat pásztázó elektronmikroszkóppal vizsgáltuk. Minden fajról elterjedési térképet is készítettünk. 41 Centrales taxont találtunk. Legfajgazdagabb a Duna volt, legfajszegényebbek a kis vizek. A taxonómiai és elterjedési vizsgálatokon túlmenően adataink számos ökológiai aspektusú elemzésre is lehetőséget nyújtottak. A taxonszám összefüggést mutatott a folyók méretével, mivel a beömlő mellékfolyók, ill. a velük kapcsolatban lévő tavak, tározók fajai is a befogadó folyóvíz fitoplanktonját gazdagítják. Nem véletlen, hogy Magyarország legnagyobb folyója a Duna Centrales közössége a legfajgazdagabb, hiszen hatalmas terület vizei kapcsolódnak hozzá és a tavi környezetre jellemző fajok a Duna lassan áramló vizében sokáig túlélnek, közülük számos szaporodni is képes benne. Állóvizek esetében a fajtelítési görbék azt mutatták, hogy a növényi tápanyagban gazdag halastavak a legfajgazdagabbak és a nagy vezetőképességű szikesek a legfajszegényebbek. A kutatás lehetőséget teremtett arra, hogy néhány taxon esetében részletes morfológiai vizsgálatot végezzünk és tisztázzuk taxonómiai helyzetüket is. | In the framework of the project 300 samples were investigated from 200 stagnant and fluvial water bodies in the eastern part of Hungary. Water chemical parameters were also measured on site, and in the laboratory. Samples were investigated by scanning electronmicroscopy. Occurrence maps were constructed for each species. Altogether 41 Centrales species were detected. The highest species number was found in the River Danube, while the lowest ones in small water bodies. Besides taxonomical and occurrence investigations, the data could be used for different other ecological analyses. The taxon number correlated with the size of the rivers, as the tributaries, and the connected lakes and reservoirs increase further the species richness of the receptive rivers. This explains the highest species richness of the largest Hungarian river, the River Danube. It has a huge catchment area with several tributaries, and standing water species survive for a long time in the slowly flowing river, many of them find favourable conditions even for reproduction. In standing waters, species accumulation curves revealed that nutrient rich fish ponds are the richest in species, and high conductivity soda lakes are the poorest. As a part of the research detailed morphological investigations could be performed in some species to understand and clarify their taxonomic position

Short-term colonization sequence of periphyton on glass slides in a large river (River Danube, near Budapest)

The colonization, structure and composition of the periphyton which developed on the artificial substratum (sand-blasted matglass-slides) positioned into current line were studied in the main arm of the River Danube at Göd (1669 riv. km) in the summer of 1997, during a low water period. Five replicates were taken on the first day in the 3rd, 6th, 9th and 24th hour, after that every day for a week, then every three days for another two weeks. Phytoplankton samples were taken four times during the study (on the 1st, 6th, 13th and 20th day) to compare the composition of benthic and planktic algae. Altogether 222 taxa were identified 95 taxa from the phytoplankton and 176 from the periphyton. The number of common species was 50. after three hours from the immersion, only coccoid bacteria (mainly colineforms) were found on the substratum but after 6 hours the first algae. The first colonizer was Diatoma vulgaris, which adheres with on apical pad. In the first few hours only a few species formed the community and low diversity and low evenness was the consequence. After 24 hours the community was already diverse with a total of 35 species. During the first week of colonization the periphyton was composed almost exclusively of quick reproduction rate R (ruderal strategy) selected species, the evenness showed an increase parallel to species richness. The basal-layer of the Danube periphyton developed at that time, where diatoms attached to the substratum mainly with on apical pad. From the second week there was a small decrease in the evenness, when the rate of slower multiplying C, C-S (competitive strategy, stress tolerant strategy) selected species increased. In the second week stalk forming species formed an intermediate layer adhering with long, branching gelatinous stalk. The thick periphyton cover filtered out planktic species from the water like a net, and more and more euplanktic Centrales species were found in the samples

Critical role of extracellular vesicles in modulating the cellular effects of cytokines

Under physiological and pathological conditions, extracellular vesicles (EVs) are present in the extracellular compartment simultaneously with soluble mediators. We hypothesized that cytokine effects may be modulated by EVs, the recently recognized conveyors of intercellular messages. In order to test this hypothesis, human monocyte cells were incubated with CCRF acute lymphoblastic leukemia cell line-derived EVs with or without the addition of recombinant human TNF, and global gene expression changes were analyzed. EVs alone regulated the expression of numerous genes related to inflammation and signaling. In combination, the effects of EVs and TNF were additive, antagonistic, or independent. The differential effects of EVs and TNF or their simultaneous presence were also validated by Taqman assays and ELISA, and by testing different populations of purified EVs. In the case of the paramount chemokine IL-8, we were able to demonstrate a synergistic upregulation by purified EVs and TNF. Our data suggest that neglecting the modulating role of EVs on the effects of soluble mediators may skew experimental results. On the other hand, considering the combined effects of cytokines and EVs may prove therapeutically useful by targeting both compartments at the same time

Lymphocytes from rheumatoid arthritis patients have elevated levels of intracellular peroxiredoxin 2, and a greater frequency of cells with exofacial peroxiredoxin 2, compared with healthy human lymphocytes

AbstractPeroxiredoxin 2 has immune regulatory functions, but its expression in human peripheral blood lymphocytes and levels in extracellular fluid in healthy subjects and rheumatoid arthritis patients are poorly described. In the present study, the median intracellular peroxiredoxin 2 protein content of lymphocytes from rheumatoid arthritis patients was more than two-fold higher compared with healthy subjects’ lymphocytes. Intracellular peroxiredoxin 3 levels were similar in healthy and rheumatoid arthritis lymphocytes. Flow cytometry detected peroxiredoxin 2 on the surface of ca. 8% of T cells and ca. 56% of B cells (median % values) of all subjects analyzed. Exofacial thioredoxin-1 was also observed. In the total lymphocyte population from rheumatoid arthritis patients, few cells (median, 6%) displayed surface peroxiredoxin 2. In contrast, a significantly increased proportion of interleukin-17+ve lymphocytes were exofacially peroxiredoxin 2+ve (median, 39%). Prdx2 was also detected in human extracellular fluids. We suggest that crucial inflammatory cell subsets, i.e. interleukin-17+ve T cells, exhibit increased exofacial redox-regulating enzymes and that peroxiredoxin 2 may be involved in the persistence of pro-inflammatory cells in chronic inflammation

Antibiotic-induced release of small extracellular vesicles (exosomes) with surface-associated DNA

Recently, biological roles of extracellular vesicles (which include among others exosomes, microvesicles and apoptotic bodies) have attracted substantial attention in various fields of biomedicine. Here we investigated the impact of sustained exposure of cells to the fluoroquinolone antibiotic ciprofloxacin on the released extracellular vesicles. Ciprofloxacin is widely used in humans against bacterial infections as well as in cell cultures against Mycoplasma contamination. However, ciprofloxacin is an inducer of oxidative stress and mitochondrial dysfunction of mammalian cells. Unexpectedly, here we found that ciprofloxacin induced the release of both DNA (mitochondrial and chromosomal sequences) and DNA-binding proteins on the exofacial surfaces of small extracellular vesicles referred to in this paper as exosomes. Furthermore, a label-free optical biosensor analysis revealed DNA-dependent binding of exosomes to fibronectin. DNA release on the surface of exosomes was not affected any further by cellular activation or apoptosis induction. Our results reveal for the first time that prolonged low-dose ciprofloxacin exposure leads to the release of DNA associated with the external surface of exosomes

Improved circulating microparticle analysis in acid-citrate dextrose (ACD) anticoagulant tube.

INTRODUCTION: Recently extracellular vesicles (exosomes, microparticles also referred to as microvesicles and apoptotic bodies) have attracted substantial interest as potential biomarkers and therapeutic vehicles. However, analysis of microparticles in biological fluids is confounded by many factors such as the activation of cells in the blood collection tube that leads to in vitro vesiculation. In this study we aimed at identifying an anticoagulant that prevents in vitro vesiculation in blood plasma samples. MATERIALS AND METHODS: We compared the levels of platelet microparticles and non-platelet-derived microparticles in platelet-free plasma samples of healthy donors. Platelet-free plasma samples were isolated using different anticoagulant tubes, and were analyzed by flow cytometry and Zymuphen assay. The extent of in vitro vesiculation was compared in citrate and acid-citrate-dextrose (ACD) tubes. RESULTS: Agitation and storage of blood samples at 37 degrees C for 1hour induced a strong release of both platelet microparticles and non-platelet-derived microparticles. Strikingly, in vitro vesiculation related to blood sample handling and storage was prevented in samples in ACD tubes. Importantly, microparticle levels elevated in vivo remained detectable in ACD tubes. CONCLUSIONS: We propose the general use of the ACD tube instead of other conventional anticoagulant tubes for the assessment of plasma microparticles since it gives a more realistic picture of the in vivo levels of circulating microparticles and does not interfere with downstream protein or RNA analyses

Low-density lipoprotein mimics blood plasma-derived exosomes and microvesicles during isolation and detection

Circulating extracellular vesicles have emerged as potential new biomarkers in a wide variety of diseases. Despite the increasing interest, their isolation and purification from body fluids remains challenging. Here we studied human pre-prandial and 4 hours postprandial platelet-free blood plasma samples as well as human platelet concentrates. Using flow cytometry, we found that the majority of circulating particles within the size range of extracellular vesicles lacked common vesicular markers. We identified most of these particles as lipoproteins (predominantly low-density lipoprotein, LDL) which mimicked the characteristics of extracellular vesicles and also co-purified with them. Based on biophysical properties of LDL this finding was highly unexpected. Current state-of-the-art extracellular vesicle isolation and purification methods did not result in lipoprotein-free vesicle preparations from blood plasma or from platelet concentrates. Furthermore, transmission electron microscopy showed an association of LDL with isolated vesicles upon in vitro mixing. This is the first study to show co-purification and in vitro association of LDL with extracellular vesicles and its interference with vesicle analysis. Our data point to the importance of careful study design and data interpretation in studies using blood-derived extracellular vesicles with special focus on potentially co-purified LDL