Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO2, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of Synechocystis strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor-repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.
- MeSH
- fluorescence MeSH
- fluorescenční barviva * metabolismus chemie MeSH
- fyziologický stres * MeSH
- mikrobiální viabilita * MeSH
- polyhydroxyalkanoáty metabolismus MeSH
- průtoková cytometrie * MeSH
- sinice metabolismus fyziologie MeSH
- Synechocystis * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Pancreaticoduodenectomy is associated with an incidence of postoperative complications of approximately 41%. One of the most severe complications is a postoperative pancreatic fistula. The exact cause of postoperative fistula development is still unknown, but it appears to be multifactorial. Proper perfusion of pancreatic remnant is essential for the healing of pancreaticojejunostomy. To date, there is no method to reliably evaluate the vascular supply of the remnant. One of the methods for the assessment of organ perfusion is the indocyanine green fluorescence. This study aims to determine if indocyanine green fluorescence is a reliable method to measure the perfusion of the post-resection pancreatic remnant. The secondary outcome is to determine if intraoperative evaluation of the vascular supply of the post-resection remnant may predict the increased risk of postoperative pancreatic fistula development. METHODS: This study is designed as a prospective, observational study. All consecutive patients undergoing open or robotic pancreaticoduodenectomies at our department during the 1st May 2024-31st December 2026 period will be enrolled. The exclusion criteria are an allergy to indocyanine green and refusal by the patient. The adequacy of the vascular supply of the post-resection pancreatic remnant will be intraoperatively evaluated using a fluorescence detector. Patients will be divided into two groups: Those with high risk of pancreatic fistula development and those with low risk. The incidence of pancreatic fistulas in both groups is to be compared. Postoperative data including morbidity, mortality, hospital stay, intensive care unit stay and postoperative fistula development will be collected. DISCUSSION: If an intraoperative assessment of the perfusion of post-resection pancreatic remnant using indocyanine green is proven to be a suitable method to estimate the increased risk of the pancreatic fistula, the list of the existing known risk factors could be expanded. In the most high-risk patients the modification of the surgical procedure could be considered. TRIAL REGISTRATION: Number: NCT06198400 ClinicalTrials.Gov. Date 08.01.2024.
- MeSH
- fluorescence MeSH
- indokyanová zeleň * MeSH
- lidé MeSH
- pankreas krevní zásobení chirurgie MeSH
- pankreatická píštěl * etiologie epidemiologie MeSH
- pankreatoduodenektomie * škodlivé účinky metody MeSH
- pooperační komplikace * etiologie diagnóza MeSH
- prospektivní studie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
- protokol klinické studie MeSH
Nano-sized carriers are widely studied as suitable candidates for the advanced delivery of various bioactive molecules such as drugs and diagnostics. Herein, the development of long-circulating stimuli-responsive polymer nanoprobes tailored for the fluorescently-guided surgery of solid tumors is reported. Nanoprobes are designed as long-circulating nanosystems preferably accumulated in solid tumors due to the Enhanced permeability and retention effect, so they act as a tumor microenvironment-sensitive activatable diagnostic. This study designs polymer probes differing in the structure of the spacer between the polymer carrier and Cy7 by employing pH-sensitive spacers, oligopeptide spacers susceptible to cathepsin B-catalyzed enzymatic hydrolysis, and non-degradable control spacer. Increased accumulation of the nanoprobes in the tumor tissue coupled with stimuli-sensitive release behavior and subsequent activation of the fluorescent signal upon dye release facilitated favorable tumor-to-background ratio, a key feature for fluorescence-guided surgery. The probes show excellent diagnostic potential for the surgical removal of intraperitoneal metastasis and orthotopic head and neck tumors with very high efficacy and accuracy. In addition, the combination of macroscopic resection followed by fluorescence-guided surgery using developed probes enable the identification and resection of most of the CAL33 intraperitoneal metastases with total tumor burden reduced to 97.2%.
- MeSH
- chytré polymery * MeSH
- fluorescence MeSH
- fluorescenční barviva chemie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorové mikroprostředí MeSH
- nádory hlavy a krku * diagnostické zobrazování chirurgie MeSH
- polymery MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In this paper, we analysed the steady state fluorescence spectra of cell suspensions containing healthy and carcinoma fibroblast mouse cells, using a genetic-algorithm-spectra-decomposition software (GASpeD). In contrast to other deconvolution algorithms, such as polynomial or linear unmixing software, GASpeD takes into account light scatter. In cell suspensions, light scatter plays an important role as it depends on the number of cells, their size, shape, and coagulation. The measured fluorescence spectra were normalized, smoothed and deconvoluted into four peaks and background. The wavelengths of intensities' maxima of lipopigments (LR), FAD, and free/bound NAD(P)H (AF/AB) of the deconvoluted spectra matched published data. In deconvoluted spectra at pH = 7, the fluorescence intensities of the AF/AB ratio in healthy cells was always higher in comparison to carcinoma cells. In addition, the AF/AB ratio in healthy and carcinoma cells were influenced differently by changes in pH. In mixtures of healthy and carcinoma cells, AF/AB decreases when more than 13% of carcinoma cells are present. Expensive instrumentation is not required, and the software is user friendly. Due to these attributes, we hope that this study will be a first step in the development of new cancer biosensors and treatments with the use of optical fibers.
- MeSH
- algoritmy * MeSH
- buněčné kultury MeSH
- fluorescence MeSH
- fluorescenční spektrometrie MeSH
- karcinom * MeSH
- myši MeSH
- software MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF REVIEW: Transurethral resection of bladder cancer (TURBT) is in its standard form an inherently imperfect technique. Fluorescence-guided photodynamic diagnosis (PDD) represents one way to improve the outcome by enhancing tumour detection. Fluorescence has been used in connection with bladder cancer since the 1970s, with a number of studies being published since then. However, the method is still not recommended as a standard part of TURBT mainly because of the limited level of evidence of concerned studies, questionable cost-effectiveness and even contradictory results. The review lists the latest articles covering this topic. RECENT FINDINGS: Several recently published meta-analyses reviewed a series of randomized controlled trials (RCTs) concerning PDD assisted TURBT. Results were generally supporting the positive effect on reduction of recurrence rate. However, the mentioned meta-analyses are overlapping in terms of reviewed RCT that provide only a low level of evidence according to a recent Cochrane review. Supposed limitations of PDD (timing of the procedure, low specificity) and possible solutions are also covered. SUMMARY: Most of the published data confirmed reduced early recurrence rate after PDD assisted TURBT comparing to standard TURBT. Its impact on late recurrence rate, progression rate or cost-effectiveness has not been sufficiently demonstrated.
- MeSH
- cystektomie metody MeSH
- fluorescence MeSH
- fotosenzibilizující látky * MeSH
- lidé MeSH
- lokální recidiva nádoru epidemiologie prevence a kontrola patologie MeSH
- nádory močového měchýře * patologie MeSH
- transuretrální resekce močového měchýře MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- MeSH
- angiografie klasifikace metody MeSH
- diagnostické techniky oftalmologické * klasifikace MeSH
- fluorescence MeSH
- indokyanová zeleň terapeutické užití MeSH
- lidé MeSH
- makulární degenerace * diagnóza etiologie MeSH
- neovaskularizace choroidey diagnostické zobrazování MeSH
- optická koherentní tomografie dějiny metody MeSH
- optické zobrazování MeSH
- retina diagnostické zobrazování patologie MeSH
- umělá inteligence MeSH
- zraková ostrost fyziologie MeSH
- zraková percepce MeSH
- zrakové testy dějiny klasifikace metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
We designed and synthesized nucleosides bearing aminophenyl- or aminonaphthyl-3-methoxychromone fluorophores attached at position 5 of cytosine or thymine and converted them to nucleoside triphosphates. The fluorophores showed solvatochromic fluorescence with strong fluorescence at 433-457 nm in non-polar solvents and very weak fluorescence at 567 nm in alcohols. The nucleosides and nucleotides also showed only negligible fluorescence in alcohols or water. The triphosphates were substrates for DNA polymerase in the enzymatic synthesis of modified DNA probes that showed only very weak fluorescence in aqueous buffer but a significant light-up and blue shift were observed when they interacted with proteins (histone H3.1 or p53 for double-stranded DNA probes or single-strand binding protein for single-stranded oligonucleotide probes). Hence, nucleotides have good potential in the construction of DNA sensors for studying protein-DNA interactions. The modified dNTPs were also transported into cells using a cyclodextrin-based transporter but they were not incorporated into the genomic DNA.
The RAD51 recombinase assembles as helical nucleoprotein filaments on single-stranded DNA (ssDNA) and mediates invasion and strand exchange with homologous duplex DNA (dsDNA) during homologous recombination (HR), as well as protection and restart of stalled replication forks. Strand invasion by RAD51-ssDNA complexes depends on ATP binding. However, RAD51 can bind ssDNA in non-productive ADP-bound or nucleotide-free states, and ATP-RAD51-ssDNA complexes hydrolyse ATP over time. Here, we define unappreciated mechanisms by which the RAD51 paralog complex RFS-1/RIP-1 limits the accumulation of RAD-51-ssDNA complexes with unfavorable nucleotide content. We find RAD51 paralogs promote the turnover of ADP-bound RAD-51 from ssDNA, in striking contrast to their ability to stabilize productive ATP-bound RAD-51 nucleoprotein filaments. In addition, RFS-1/RIP-1 inhibits binding of nucleotide-free RAD-51 to ssDNA. We propose that 'nucleotide proofreading' activities of RAD51 paralogs co-operate to ensure the enrichment of active, ATP-bound RAD-51 filaments on ssDNA to promote HR.
- MeSH
- adenosindifosfát farmakologie MeSH
- adenosintrifosfát farmakologie MeSH
- Caenorhabditis elegans metabolismus MeSH
- druhová specificita MeSH
- fluorescence MeSH
- interferometrie MeSH
- jednovláknová DNA metabolismus MeSH
- nukleotidy metabolismus MeSH
- proteiny Caenorhabditis elegans metabolismus MeSH
- rekombinasa Rad51 chemie metabolismus MeSH
- sekvenční homologie aminokyselin * MeSH
- stabilita proteinů účinky léků MeSH
- vazba proteinů účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Endoskopické optické zobrazovací metody byly vyvinuty s cílem časné detekce slizničních lézí suspektních z prekancerózních nebo maligních změn. V ORL oblasti je to především oblast dutiny ústní, orofaryngu, hypofaryngu a hrtanu. Zobrazovací metody se dělí do dvou základních skupin. Horizontální metody vizualizují povrch sliznice (autofluorescence, fotodynamická diagnostika, narrow band imaging, zvětšovací a kontaktní endoskopie) a vertikální metody zobrazují různé vrstvy sliznice (optická koherentní tomografie a konfokální endomikroskopie). V ORL oblasti je nejvíce používaná metoda narrow band imaging (NBI).
Endoscopic optical imaging methods have been developed with the aim of early detection of lesions suspected from precancerous or malignant changes. In ENT area, it is primarily used in oral cavity, oropharynx, hypopharynx and larynx. They can be divided into two basic groups. Horizontal methods visualize the mucosal surface (autofluorescence, photodynamic diagnosis, narrow band imaging, magnifying and contact endoscopy) and vertical methods – showing the different layers of the mucosa (optical coherence tomography and confocal endomicroscopy). In the ENT area, the mostly used method is narrow band imaging (NBI).
- MeSH
- fluorescence MeSH
- intravitální mikroskopie MeSH
- lidé MeSH
- nádory hlavy a krku * diagnostické zobrazování MeSH
- optické zobrazování * klasifikace MeSH
- úzkopásmové zobrazení MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Magnetopriming has emerged as a promising seed-priming method, improving seed vigor, plant performance and productivity under both normal and stressed conditions. Various recent reports have demonstrated that improved photosynthesis can lead to higher biomass accumulation and overall crop yield. The major focus of the present review is magnetopriming-based, improved growth parameters, which ultimately favor increased photosynthetic performance. The plants originating from magnetoprimed seeds showed increased plant height, leaf area, fresh weight, thick midrib and minor veins. Similarly, chlorophyll and carotenoid contents, efficiency of PSII, quantum yield of electron transport, stomatal conductance, and activities of carbonic anhydrase (CA), Rubisco and PEP-carboxylase enzymes are enhanced with magnetopriming of the seeds. In addition, a higher fluorescence yield at the J-I-P phase in polyphasic chlorophyll a fluorescence (OJIP) transient curves was observed in plants originating from magnetoprimed seeds. Here, we have presented an overview of available studies supporting the magnetopriming-based improvement of various parameters determining the photosynthetic performance of crop plants, which consequently increases crop yield. Additionally, we suggest the need for more in-depth molecular analysis in the future to shed light upon hidden regulatory mechanisms involved in magnetopriming-based, improved photosynthetic performance.
