A folyamatos szubkután glükózmonitorizálás szerepe az intenzív terápiában

A kritikus állapotú betegek stressz-hyperglykaemiájának értékelése az elmúlt évtizedben jelentősen megváltozott. A vércukor szoros kontrolljának mortalitást csökkentő hatását igazolta több jelentős vizsgálat, ugyanakkor az ezt célzó inzulinkezelés megnöveli a hypoglykaemia kockázatát, amely független mortalitási tényező lehet. A hypoglykaemia szempontjából kiemelt jelentőségű a gyermekpopuláció, a fejlődő idegrendszer miatt. Ezek alapján joggal merül fel a vércukorváltozások intenzív osztályos monitorizálásának igénye, különösen gyermek betegeknél. A hagyományos, vérmintából történő vércukor-meghatározások nem tesznek lehetővé kellően szoros monitorizálást. A cukorbetegek számára kifejlesztett, a szövet közti glükóz meghatározásán alapuló módszerek (continuous glucose monitoring) jó alternatívát jelenthetnek az intenzív osztályos monitorizálásra, amennyiben felmérjük a rendszer korlátait. A mérés a szövet közti folyadékban történik, így a szöveti perfúzió változásai zavarhatják a pontosságát. A folyamatos glükózmonitoring módszer intenzív osztályos alkalmazását jelenleg még nem javasolják, amíg a rendszer megbízhatóságáról nem áll rendelkezésre elegendő adat. Összefoglaló közleményükben a szerzők a magyar klinikai gyakorlatban elterjedt Medtronic folyamatos szubkután glükózmonitorizáló rendszert értékelik, részben saját eredményeik alapján. Orv. Hetil., 2013, 154, 1043–1048. | Critical care associated with stress hyperglycaemia has gained a new view in the last decade since the demonstration of the beneficial effects of strong glycaemic control on the mortality in intensive care units. Strong glycaemic control may, however, induce hypoglycaemia, resulting in increased mortality, too. Pediatric population has an increased risk of hypoglycaemia because of the developing central nervous system. In this view there is a strong need for close monitoring of glucose levels in intensive care units. The subcutaneous continuous glucose monitoring developed for diabetes care is an alternative for this purpose instead of regular blood glucose measurements. It is important to know the limitations of subcutaneous continuous glucose monitoring in intensive care. Decreased tissue perfusion may disturb the results of subcutaneous continuous glucose monitoring, because the measurement occurs in interstitial fluid. The routine use of subcutaneous continuous glucose monitoring in intensive care units is not recommended yet until sufficient data on the reliability of the system are available. The Medtronic subcutaneous continuous glucose monitoring system is evaluated in the review partly based on the authors own results. Orv. Hetil., 2013, 154, 1043–1048

A komplementrendszer immunfunkciókat szabályozó szerepe fiziológiás és kóros folyamatok során = Immunoregulatory role of complement under physiological and pathological conditions

A komplementrendszer immunvédekezésünk szerves része. A legnagyobb mennyiségben előforduló komponens, a C3 szerepe igen változatos; a patogének eliminálásától az immunválasz szabályozásáig terjed. A számos biológiai funkciót főként a C3 aktivációs fragmentumai közvetítik, amelyek különböző sejtek különböző komplementreceptoraihoz kötődnek. Célunk az volt, hogy a C3 újabb, immunfolyamatokat szabályozó szerepét feltárjuk. Kísérleteink eredményei eddig nem ismert molekuláris és sejtes mechanizmusokra derítettek fényt, egyrészt a limfociták CR1 által közvetített gátlásának további tanulmányozásával, másrészt az antigénbemutató sejtek funkcióival kapcsolatban. Vizsgálataink során autoimmun betegek (RA és SLE) sejtjeit is vizsgáltuk, valamint az SM egér-modelljét, az EAE-t is tanulmányoztuk. Eredményeink nemcsak azért fontosak, mert általuk jobban megértjük az alapvető immunfolyamatokat, hanem azért is, mert egyes autoimmun-betegségek kezelésében reménykeltő cél-molekulát sikerült azonosítanunk. Eredményeinket számos ""peer-reviewed"" cikkben közöltük (össz-IF: 66), továbbá a projekt anyagából két PhD-fokozat született és további kettő folyamatban van. Eredményeink arra sarkalltak, hogy kutatásainkat kiterjesszük a munkatervben nem részletezett területre is, melynek során Dr. Prechl Józseffel és Dr. Papp Krisztiánnal (MTA-ELTE Immunológiai Kutatócsoport) együttműködve mikro-array rendszert dolgoztunk ki az ellenanyag (köztük autoantitestek) általi komplementaktiválás kimutatására. | The complement system is an integral part of our immune system. The role of its most abundant protein, component C3, is very versatile – it ranges from the elimination of pathogens to the regulation of immune responses. The various biological functions are mainly mediated by the activation fragments of C3, via their interaction with different complement receptors expressed by different cell types. Our goal was to reveal new regulatory functions of C3. We have described so far unknown molecular and cellular interactions, further analysed the CR1-mediated inhibiton of lymphocyte functions and the role of C3 in the function of antigenpresenting cells. We extended our studies to autoimmune patients – such as RA and SLE -, furthermore to EAE, the mouse modell of SM. Our results are important not only beacuse they help better understand basic immunological processes, but also because we could identify a promising target-molecule for the treatment of autoimmune disorders. We published our results in peer-reviewed international journals (total IF: 66), furthermore two PhD-degrees were accomplished and further two will be obtained based on this OTKA-project. Our results urged us to extend the research to a new area, namely the development of a protein-microarray system, which can be used to detect complement activation initiated by antibodies. This work was accomplished by a cooperation with Drs. J.Prechl and K.Papp at the Immunology Research Group of the HAS at ELU

Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit

BACKGROUND: Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion. PATIENTS AND METHODS: In 38 pediatric patients (age range, 0–18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson’s correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05). RESULTS: CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson’s correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson’s correlation coefficient: 0.83). CONCLUSIONS: The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions

The SWI/SNF ATP-Dependent Chromatin Remodeling Complex in Arabidopsis Responds to Environmental Changes in Temperature-Dependent Manner

SWI/SNF ATP-dependent chromatin remodeling complexes (CRCs) play important roles in the regulation of transcription, cell cycle, DNA replication, repair, and hormone signaling in eukaryotes. The core of SWI/SNF CRCs composed of a SWI2/SNF2 type ATPase, a SNF5 and two of SWI3 subunits is sufficient for execution of nucleosome remodeling in vitro. The Arabidopsis genome encodes four SWI2/SNF2 ATPases, four SWI3, a single SNF5 and two SWP73 subunits. Genes of the core SWI/SNF components have critical but not fully overlapping roles during plant growth, embryogenesis, and sporophyte development. Here we show that the Arabidopsis swi3c mutant exhibits a phenotypic reversion when grown at lower temperature resulting in partial restoration of its embryo, root development and fertility defects. Our data indicates that the swi3c mutation alters the expression of several genes engaged in low temperature responses. The location of SWI3C-containing SWI/SNF CRCs on the ICE1, MYB15 and CBF1 target genes depends on the temperature conditions, and the swi3c mutation thus also influences the transcription of several cold-responsive (COR) genes. These findings, together with genetic analysis of swi3c/ice1 double mutant and enhanced freezing tolerance of swi3c plants illustrate that SWI/SNF CRCs contribute to fine-tuning of plant growth responses to different temperature regimes

An improved 96 well plate format lipid quantification assay for standardization of experiments with extracellular vesicles

The field of extracellular vesicles is an exponentially growing segment of biomedical sciences. However, the problems of normalisation and quantification of extracellular vesicle samples have not been completely solved yet. Currently, extracellular vesicle samples are standardized on the basis of their protein content sometimes combined with determination of the particle number. However, even this combined approach may result in inaccuracy and overestimation of the extracellular vesicle concentration. Lipid bilayers are indispensable components of extracellular vesicles. Therefore, a lipidbased quantification, in combination with the determination of particle count and/or protein content, appears to be a straightforward and logical approach for the extracellular vesicle field. In this study we set the goal to improve the previously reported sulfo-phospho-vanillin total lipid assay. We introduced an aqueous phase liposome standard (DOPC) to replace the purified lipid standards in organic solvents (used commonly in previous studies). Furthermore, we optimized the concentration of the vanillin reagent in the assay. We found that elimination of organic solvents from the reaction mixture could abolish the background colour that interfered with the assay. Comparison of the optimised assay with a commercial lipid kit (based on the original sulfo-phospho-vanillin lipid assay) showed an increase of sensitivity by approximately one order of magnitude. Thus, here we report a quick, reliable and sensitive test that may fill an existing gap in extracellular vesicle standardisation. When using the optimised total lipid assay reported here, extracellular vesicle lipid measurements can be as easy as measuring proteins with a simple BCA test

Damage-mediated macrophage polarization in sterile inflammation

Most of the leading causes of death, such as cardiovascular diseases, cancer, dementia, neurodegenerative diseases, and many more, are associated with sterile inflammation, either as a cause or a consequence of these conditions. The ability to control the progression of inflammation toward tissue resolution before it becomes chronic holds significant clinical potential. During sterile inflammation, the initiation of inflammation occurs through damage-associated molecular patterns (DAMPs) in the absence of pathogen-associated molecules. Macrophages, which are primarily localized in the tissue, play a pivotal role in sensing DAMPs. Furthermore, macrophages can also detect and respond to resolution-associated molecular patterns (RAMPs) and specific pro-resolving mediators (SPMs) during sterile inflammation. Macrophages, being highly adaptable cells, are particularly influenced by changes in the microenvironment. In response to the tissue environment, monocytes, pro-inflammatory macrophages, and pro-resolution macrophages can modulate their differentiation state. Ultimately, DAMP and RAMP-primed macrophages, depending on the predominant subpopulation, regulate the balance between inflammatory and resolving processes. While sterile injury and pathogen-induced reactions may have distinct effects on macrophages, most studies have focused on macrophage responses induced by pathogens. In this review, which emphasizes available human data, we illustrate how macrophages sense these mediators by examining the expression of receptors for DAMPs, RAMPs, and SPMs. We also delve into the signaling pathways induced by DAMPs, RAMPs, and SPMs, which primarily contribute to the regulation of macrophage differentiation from a pro-inflammatory to a pro-resolution phenotype. Understanding the regulatory mechanisms behind the transition between macrophage subtypes can offer insights into manipulating the transition from inflammation to resolution in sterile inflammatory diseases

An implanted device enables in vivo monitoring of extracellular vesicle-mediated spread of pro-inflammatory mast cell response in mice

Abstract Mast cells have been shown to release extracellular vesicles (EVs) in vitro. However, EV-mediated mast cell communication in vivo remains unexplored. Primary mast cells from GFP-transgenic and wild type mice, were grown in the presence or absence of lipopolysaccharide (LPS), and the secreted EVs were separated from the conditioned media. Mast cell-derived EVs were next cultured with LPS-naïve mast cells, and the induction of TNF-α expression was monitored. In addition, primary mast cells were seeded in diffusion chambers that were implanted into the peritoneal cavities of mice. Diffusion chambers enabled the release of GFP+ mast cell-derived EVs in vivo into the peritoneal cavity. Peritoneal lavage cells were assessed for the uptake of GFP+ EVs and for TNF-α production. In vitro, LPS-stimulated mast cell-derived EVs were efficiently taken up by non-stimulated mast cells, and induced TNF-α expression in a TLR4, JNK and P38 MAPK dependent manner. In vivo, using implanted diffusion chambers, we confirmed the release and transmission of mast cell-derived EVs to other mast cells with subsequent induction of TNF-α expression. These data show an EV-mediated spreading of pro-inflammatory response between mast cells, and provide the first in vivo evidence for the biological role of mast cell-derived EVs