Photosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (through Time Controller offered by Olympus or Experiment Designer offered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with the Cell⊕Finder software was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) the Cell⊕Finder software with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser. Cell⊕Finder can be downloaded from http://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity in Synechocystis sp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

• Klíčová slova
• automated microscopy, confocal microscopy, photoprotection, photosynthetic membrane, remote controlled microscopy,
• MeSH
• konfokální mikroskopie přístrojové vybavení   metody   MeSH
• laboratorní automatizace přístrojové vybavení   metody   MeSH
• osvětlení MeSH
• software MeSH
• Synechocystis chemie   ultrastruktura   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We assessed blood-brain barrier (BBB) disruption in early stage of photothrombotic focal cerebral ischemia in the rat. We specifically looked for contralateral changes in BBB permeability and tested the influence of two anesthetics on the results. Adult Wistar rats were randomly anesthetized with pentobarbital (PB) or ketamine-xylazine (KX). Rats received intravenously (i.v.) Rose Bengal followed by Evans Blue (EB). Stereotactically defined spots on denuded skull were irradiated by laser (532 nm) for 18 min. Twenty four hours later, rats were killed, brains perfused, fixated, sectioned and slices analyzed by fluorescence microscopy. Volume of necrosis and volume of EB-albumin extravasation were calculated. Evidence of BBB breakdown in remote brain areas was sought and compared to sham handled controls. BBB disruption was consistently present, frequently with EB-albumin accumulating cells. Total lesion volume did not significantly differ among groups (TLVPB=9.4±1.3 mm³ vs. TLVKX=8.3±2.1 mm³); same was true for the volume of necrosis (NVPB=5.1±0.7 mm³ vs. NVKX=6.3±1.9 mm³). However, volume of EB-albumin extravasation area was significantly smaller in KX group (EBEVPB=4.3±0.8 mm³ vs. EBEVKX=2.0±0.5 mm³; p=0.0293). Median background EB-fluorescence signal density was higher in PB group (p<0.0001). Furthermore, regional increase in EB-fluorescence was found in two animals in PB group. Our study shows that anesthesia with NMDA-antagonist ketamine and α2-adrenergic agonist xylazine may reduce BBB breakdown in photothrombosis. Pentobarbital anesthesia lead to increased BBB permeability in the contralateral hemisphere.

• MeSH
• alfa-2-adrenergní receptory - agonisté farmakologie   MeSH
• anestetika farmakologie   MeSH
• antagonisté excitačních aminokyselin farmakologie   MeSH
• hematoencefalická bariéra účinky léků   patologie   MeSH
• hypnotika a sedativa farmakologie   MeSH
• intrakraniální trombóza patologie   MeSH
• ischemie mozku patologie   MeSH
• ketamin farmakologie   MeSH
• krysa rodu Rattus MeSH
• lasery MeSH
• nekróza patologie   MeSH
• pentobarbital farmakologie   MeSH
• potkani Wistar MeSH
• receptory N-methyl-D-aspartátu antagonisté a inhibitory   MeSH
• sloučeniny dusíkatého yperitu farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-2-adrenergní receptory - agonisté MeSH
• anestetika MeSH
• antagonisté excitačních aminokyselin MeSH
• hypnotika a sedativa MeSH
• ketamin MeSH
• pentobarbital MeSH
• receptory N-methyl-D-aspartátu MeSH
• sloučeniny dusíkatého yperitu MeSH
• xylamine MeSH Prohlížeč

Myeloperoxidase (MPO) is a heme enzyme abundantly expressed in polymorphonuclear neutrophils. MPO is enzymatically capable of catalyzing the generation of reactive oxygen species (ROS) and the consumption of nitric oxide (NO). Thus MPO has both potent microbicidal and, upon binding to the vessel wall, pro-inflammatory properties. Interestingly, MPO - a highly cationic protein - has been shown to bind to both endothelial cells and leukocyte membranes. Given the anionic surface charge of red blood cells, we investigated binding of MPO to erythrocytes. Red blood cells (RBCs) derived from patients with elevated MPO plasma levels showed significantly higher amounts of MPO by flow cytometry and ELISA than healthy controls. Heparin-induced MPO-release from patient-derived RBCs was significantly increased compared to controls. Ex vivo experiments revealed dose and time dependency for MPO-RBC binding, and immunofluorescence staining as well as confocal microscopy localized MPO-RBC interaction to the erythrocyte plasma membrane. NO-consumption by RBC-membrane fragments (erythrocyte "ghosts") increased with incrementally greater concentrations of MPO during incubation, indicating preserved catalytic MPO activity. In vivo infusion of MPO-loaded RBCs into C57BL/6J mice increased local MPO tissue concentrations in liver, spleen, lung, and heart tissue as well as within the cardiac vasculature. Further, NO-dependent relaxation of aortic rings was altered by RBC bound-MPO and systemic vascular resistance significantly increased after infusion of MPO-loaded RBCs into mice. In summary, we find that MPO binds to RBC membranes in vitro and in vivo, is transported by RBCs to remote sites in mice, and affects endothelial function as well as systemic vascular resistance. RBCs may avidly bind circulating MPO, and act as carriers of this leukocyte-derived enzyme.

• Klíčová slova
• Cell membranes, Erythrocyte, Myeloperoxidase, Systemic vascular resistance, Vascular endothelium-dependent relaxation,
• MeSH
• akutní koronární syndrom krev   patologie   MeSH
• aorta účinky léků   MeSH
• biologický transport MeSH
• cévní endotel účinky léků   MeSH
• cévní rezistence účinky léků   MeSH
• erytrocyty metabolismus   patologie   MeSH
• heparin chemie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• orgánové kultury - kultivační techniky MeSH
• oxid dusnatý metabolismus   farmakologie   MeSH
• peroxidasa krev   farmakologie   MeSH
• srdce účinky léků   MeSH
• srdeční selhání krev   patologie   MeSH
• techniky tkáňových kultur MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• heparin MeSH
• oxid dusnatý MeSH
• peroxidasa MeSH

Fluorescence-based sensing is a straightforward and powerful technique with high sensitivity for the detection of a wide range of chemical and biological analytes. Integrating the high sensing capabilities of fluorescent probes with wireless navigation systems can enable the extension of their operational range, even in challenging scenarios with limited accessibility or involving hazardous substances. This study presents the development of molecularly engineered magneto-fluorescent microrobots based on the push-pull quinonoids by incorporating magnetic nanoparticles using a reprecipitation approach with the aim of detecting high-energy explosives and antibiotics in aqueous environments. The magnetic components in the microrobots offer remotely controlled navigability toward the intended target areas under the guidance of external magnetic fields. Upon interactions with either explosives (picric acid) or antibiotics (tetracycline), the microrobots' intrinsic fluorescence switches to a "fluorescence off" state, enabling material-based intelligence for sensing applications. The molecular-level interactions that underlie "on-off" fluorescence state switching upon engagement with target molecules are elucidated through extensive spectroscopy, microscopy, and X-ray diffraction analyses. The microrobots' selectivity toward target molecules is achieved by designing microrobots with amine functionalities capable of intermolecular hydrogen bonding with the acidic hydroxyl group of picric acid, leading to the formation of water-soluble charge transfer picrate complexes through proton transfer. Similarly, proton transfer interactions play a key role in tetracycline detection. The selective fluorescence switching performance of microrobots in fluidic channel experiments illustrates their selective sensing intelligence for target molecules in an externally controlled manner, highlighting their promising characteristics for sensing applications in real-world scenarios.

• Klíčová slova
• charge transfer complexes, environmental monitoring, fluorescence sensing, magnetic microrobots, organic pollutants,
• MeSH
• antibakteriální látky * analýza   MeSH
• fluorescenční barviva * chemie   MeSH
• magnetické nanočástice * chemie   MeSH
• tetracyklin * analýza   MeSH
• voda chemie   MeSH
• výbušné látky * analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky * MeSH
• fluorescenční barviva * MeSH
• magnetické nanočástice * MeSH
• picric acid MeSH Prohlížeč
• pikráty MeSH
• tetracyklin * MeSH
• voda MeSH
• výbušné látky * MeSH