Localized infection of a plant can be mapped by a sequence of images capturing chlorophyll fluorescence transients in actinic light. Choice of the actinic light protocol co-determines fluorescence contrast between infected leaf segment and surrounding healthy tissue. Frequently, biology cannot predict with which irradiance protocol, in which fluorescence image of the sequence, and in which segment of the image there will be the highest contrast between the healthy and infected tissue. Here, we introduce a new technique that can be applied to identify the combination of chlorophyll fluorescence images yielding the highest contrast. The sets of the most contrasting images vary throughout the progress of the infection. Such specific image sets, stress-revealing fluorescence signatures, can be found for the initial and late phases of the infection. Using these signatures, images can be divided into segments that show tissue in different infection phases. We demonstrate the capacity of the algorithm in an investigation of infection of the model plant Arabidopsis thaliana by the bacterium Pseudomonas syringae. We show that the highest contrast is found with transients elicited by fluctuating, harmonically modulated irradiance with long periods.

• MeSH
• Arabidopsis mikrobiologie   fyziologie   MeSH
• chlorofyl fyziologie   MeSH
• fluorescence * MeSH
• nemoci rostlin MeSH
• počítačové zpracování obrazu MeSH
• Pseudomonas syringae fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH

Magnetic textile solid phase extraction, based on the use of magnetically modified non-woven textile impregnated with chitosan, was successfully employed for the preconcentration of acid food dyes from water solutions. The photos of textile squares with the adsorbed dye were taken with a mobile phone. The image analysis of the photos was performed using appropriate freeware. The values of saturation, obtained through the HSB color space, were proportional to the dye concentration in the analyzed samples. Described inexpensive, simple and elution free assay enables analysis of dyes concentration in various solutions. This novel method has a potential to be a useful alternative to existing semiquantitative determination procedures, especially for dyes analysis.

• Klíčová slova
• Acid dyes, Chitosan, Image analysis, Magnetic textile solid phase extraction, Non-woven textile,
• MeSH
• adsorpce MeSH
• extrakce na pevné fázi přístrojové vybavení   metody   MeSH
• indigotindisulfonát sodný analýza   MeSH
• magnetismus MeSH
• mobilní telefon MeSH
• počítačové zpracování obrazu MeSH
• potravinářská barviva analýza   MeSH
• software MeSH
• textilie * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• indigotindisulfonát sodný MeSH
• potravinářská barviva MeSH

The measurement of micronuclei (MN) in human peripheral blood lymphocytes is frequently used in molecular epidemiology as one of the preferred methods for assessing chromosomal damage resulting from environmental mutagen exposure. In the present study, we evaluated the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), volatile organic compounds (VOC) and smoking on the frequency of MN in a group of 56 city policemen living and working in Prague. The average age of the participants was 34+/-6 years. The study was conducted on the same subjects in February and May 2007. The concentrations of air pollutants were obtained from personal and stationary monitoring. A statistically significant decrease in the levels of pollutants was observed in May when compared with February, with the exception of toluene levels measured by stationary monitoring. The frequency of MN was determined by the automatic image scoring (MetaSystems Metafer 4, version 3.2.1) of DAPI-stained slides. The results of the image analysis indicated a significant difference in the frequency of MN (mean levels 7.32+/-3.42 and 4.67+/-2.92, for February and May, respectively). Our study suggests that automatic image analysis of MN is a highly sensitive method for evaluating the effect of c-PAHs and confirms that there are no differences between smokers and nonsmokers. These results demonstrate the ability of c-PAHs to increase MN frequency, even if the exposure to c-PAHs occurred up to 60 days before the collection of biological material. Our work is the first human biomonitoring study focused on the measurement of MN by automated image analysis for assessing chromosomal damage as a result of environmental mutagen exposure.

• MeSH
• automatizace MeSH
• dospělí MeSH
• karcinogeny životního prostředí farmakologie   MeSH
• kotinin moč   MeSH
• kouření škodlivé účinky   MeSH
• lidé MeSH
• lymfocyty účinky léků   MeSH
• mikrojaderné testy MeSH
• mikrojádra chromozomálně defektní chemicky indukované   MeSH
• počítačové zpracování obrazu * MeSH
• policie MeSH
• polycyklické aromatické uhlovodíky farmakologie   MeSH
• studie případů a kontrol MeSH
• znečištění ovzduší škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• karcinogeny životního prostředí MeSH
• kotinin MeSH
• polycyklické aromatické uhlovodíky MeSH

OBJECTIVE: A model of estrogen (E)-induced rat anterior pituitary hyperplasia blocked partly by thyroid hormones (estradiol plus thyreoidin [ET]) and nearly completely by lisuride (estradiol plus lisuride [EL]) and thyreoidin plus lisuride combination (estradiol plus thyreoidin plus lisuride [ETL]) was used to test a computer image analysis program, LUCIA, for argyrophilic nucleolar organizer region (AgNOR) evaluation. STUDY DESIGN: Nuclear and AgNOR area were measured in more than 700 cells in each experimental group. The nucleoli were also typed without the automated procedure. RESULTS: Mean nuclear area was significantly higher in E and lower in T. In all groups with blocked hyperplasia (ET, EL, ETL) the mean nuclear area was lower than in T. Mean AgNOR area was significantly higher in E but also, to a lesser extent, in T. The ET combination produced a partly diminished mean AgNOR area as compared to E; a severe reduction was observed in the EL and ETL groups. In nucleolar typing, thyreoidin, lisuride and their combination inhibited the increase in large nucleoli with finely dispersed AgNORs induced by estradiol. CONCLUSION: The LUCIA image analysis program for AgNOR evaluation proved able to monitor the slight changes in AgNORs in thyroid hormones- and lisuride-inhibited, estradiol-induced rat anterior pitutary hyperplasia.

• MeSH
• adenohypofýza účinky léků   patologie   MeSH
• agonisté dopaminu farmakologie   MeSH
• buněčné jádro MeSH
• estradiol farmakologie   MeSH
• hormony štítné žlázy farmakologie   MeSH
• hyperplazie chemicky indukované   MeSH
• krysa rodu Rattus MeSH
• lisurid farmakologie   MeSH
• organizátor jadérka patologie   MeSH
• počítačové zpracování obrazu metody   MeSH
• potkani Wistar MeSH
• senzitivita a specificita MeSH
• velikost orgánu MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• agonisté dopaminu MeSH
• estradiol MeSH
• hormony štítné žlázy MeSH
• lisurid MeSH
• thyroidin MeSH Prohlížeč

Radiomic features are usually used to predict target variables such as the absence or presence of a disease, treatment response, or time to symptom progression. One of the potential clinical applications is in patients with Parkinson's disease. Robust radiomic features for this specific imaging method have not yet been identified, which is necessary for proper feature selection. Thus, we are assessing the robustness of radiomic features in dopamine transporter imaging (DaT). For this study, we made an anthropomorphic head phantom with tissue heterogeneity using a personal 3D printer (polylactide 82% infill); the bone was subsequently reproduced with plaster. A surgical cotton ball with radiotracer (123I-ioflupane) was inserted. Scans were performed on the two-detector hybrid camera with acquisition parameters corresponding to international guidelines for DaT single photon emission tomography (SPECT). Reconstruction of SPECT was performed on a clinical workstation with iterative algorithms. Open-source LifeX software was used to extract 134 radiomic features. Statistical analysis was made in RStudio using the intraclass correlation coefficient (ICC) and coefficient of variation (COV). Overall, radiomic features in different reconstruction parameters showed a moderate reproducibility rate (ICC = 0.636, p <0.01). Assessment of ICC and COV within CT attenuation correction (CTAC) and non-attenuation correction (NAC) groups and within particular feature classes showed an excellent reproducibility rate (ICC > 0.9, p < 0.01), except for an intensity-based NAC group, where radiomic features showed a good repeatability rate (ICC = 0.893, p <0.01). By our results, CTAC becomes the main threat to feature stability. However, many radiomic features were sensitive to the selected reconstruction algorithm irrespectively to the attenuation correction. Radiomic features extracted from DaT-SPECT showed moderate to excellent reproducibility rates. These results make them suitable for clinical practice and human studies, but awareness of feature selection should be held, as some radiomic features are more robust than others.

• MeSH
• jednofotonová emisní výpočetní tomografie * MeSH
• lidé MeSH
• nortropany * MeSH
• počítačové zpracování obrazu * metody   MeSH
• radiomika MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ioflupane MeSH Prohlížeč
• nortropany * MeSH

The aim of this study was to follow the skin penetration of a model lipophilic compound (Nile red) delivered by nanoparticulate carriers, the so-called lipid nanocapsules. The nanocapsules consisting of an oil core stabilized by amixture of surfactants were prepared by the phase inversion temperature method. Varying the particle composition (the oil/surfactant ratio) nanoparticles of different size were prepared and characterized. The penetration profile of Nile red delivered into the porcine skin by the nanoparticles compared to non-particulate samples was determined using fluorescence microscopy combined with a novel, statistically robust quantitative image analysis method. This study demonstrated that lipid nanoparticles promoted the skin penetration of encapsulated Nile red in comparison with all the non-particulate samples. Nile red delivered by the lipid-based nanoparticles was able to diffuse across the stratum corneum and partition itself uniformly in the epidermis. No relationship between Nile red penetration into the skin and the particle size was found. Moreover, the presence of sodium chloride in the water phase had a negative impact on the Nile red penetration into the skin. The results indicate that the physico-chemical circumstances of the nanoparticulate formulation play the major role in the penetration of lipophilic substances into the skin.

• Klíčová slova
• Image analysis, Lipid nanoparticles, Nile red, Phase inversion temperature method, Skin penetration,
• MeSH
• epidermis účinky léků   MeSH
• fluorescenční mikroskopie MeSH
• konfokální mikroskopie MeSH
• kožní absorpce MeSH
• kůže účinky léků   patologie   MeSH
• lékové transportní systémy MeSH
• lipidy chemie   MeSH
• nanočástice chemie   MeSH
• nanokapsle chemie   MeSH
• nosiče léků chemie   MeSH
• oleje chemie   MeSH
• oxaziny chemie   MeSH
• počítačové zpracování obrazu MeSH
• povrchově aktivní látky chemie   MeSH
• prasata MeSH
• software MeSH
• transmisní elektronová mikroskopie MeSH
• velikost částic MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lipidy MeSH
• nanokapsle MeSH
• nile red MeSH Prohlížeč
• nosiče léků MeSH
• oleje MeSH
• oxaziny MeSH
• povrchově aktivní látky MeSH

ELF(R)97 phosphate (ELFP) is a phosphatase substrate which produces ELF(R)97 alcohol (ELFA), a fluorescent water-insoluble product, upon hydrolysis. We studied the kinetics of ELFA precipitation in freshwater samples at levels of total plankton and single phytoplankton cells, and tested the suitability of ELFP for measurement of surface-bound algal extracellular phosphatases. Samples from acidic Plesné Lake (pH approximately 5; high phosphatase activity) and eutrophic Rímov reservoir (pH approximately 7-10; moderate phosphatase activity) were incubated with ELFP for 5-300 min, fixed with HgCl2 and filtered through polycarbonate filters. Relative fluorescence of filter-retained ELFA precipitates was quantified with image analysis. Time-courses of ELFA formation exhibited lag periods followed by finite periods of linear increase. In Plesné Lake, lag-times were shorter (1-18 min) and rates of increase in ELFA fluorescence higher (by approximately 2 orders of magnitude) than in Rímov reservoir (lag-times 30-200 min). Similar patterns of ELFA formation kinetics were also observed in Plesné Lake samples in cuvette spectrofluorometer measurements (which failed in Rímov reservoir). Linear regression of seasonal data on rates of increase in ELFA fluorescence from image cytometry and spectrofluorometry (r2 = 0.65, n = 10) allowed for calibration of image cytometry in terms of amount of cell-associated ELFA. Preliminary measurements of extracellular phosphatase activities of several algae resulted in rates (10-2260 fmol cell-1 h-1) which are comparable to data reported in the literature for algal cultures.

• MeSH
• chinazolinony MeSH
• chinazoliny metabolismus   MeSH
• fluorescenční barviva metabolismus   MeSH
• fluorescenční spektrometrie MeSH
• fosfatasy metabolismus   MeSH
• fytoplankton enzymologie   MeSH
• organofosforové sloučeniny metabolismus   MeSH
• plankton enzymologie   MeSH
• počítačové zpracování obrazu MeSH
• sladká voda MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• 2-(5'-chloro-2'-phosphoryloxyphenyl)-6-chloro-4-(3H)-quinazolinone MeSH Prohlížeč
• chinazolinony MeSH
• chinazoliny MeSH
• fluorescenční barviva MeSH
• fosfatasy MeSH
• organofosforové sloučeniny MeSH

Multi-color fluorescence emission from leaf tissues is presented as a powerful reporter on plant biochemistry and physiology that can be applied both at macro- and micro-scales. The blue-green fluorescence emission is typically excited by ultraviolet (UV) excitation. However, this approach cannot be applied in investigating intact leaf interior because the UV photons are largely absorbed in the epidermis of the leaf surface. This methodological barrier is eliminated by replacing the UV photon excitation by excitation with two infra-red photons of the same total energy. We demonstrate this approach by using two-photon excitation for microscopy of Arabidopsis thaliana leaves infected by pathogenic bacterium Pseudomonas syringae. The leaf structures are visualized by red chlorophyll fluorescence emission reconstructed in 3-D images while the bacteria are detected by the green emission of engineered fluorescence protein.

• MeSH
• Arabidopsis metabolismus   mikrobiologie   MeSH
• chlorofyl metabolismus   MeSH
• fluorescenční spektrometrie MeSH
• listy rostlin metabolismus   mikrobiologie   MeSH
• mezofylové buňky cytologie   metabolismus   MeSH
• nemoci rostlin mikrobiologie   MeSH
• Pseudomonas syringae fyziologie   MeSH
• tabák metabolismus   mikrobiologie   MeSH
• zobrazování trojrozměrné metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH

The aim of this article is to compare experimental resolution under different conditions with theoretical resolution predicted using electromagnetic diffraction theory. Imaging properties of fluorescent beads of three different diameters (0.1 microm, 0.2 microm, and 0.5 microm) as well as imaging properties of four different fluorescence-stained DNA targets (ABL gene, BCR gene, centromere 6, and centromere 17) are studied. It is shown how the dependence of the resolution on object size varies with wavelength (520 nm versus 580 nm), type of microscopy (wide-field, confocal using Nipkow disk, confocal laser scanning) and basic image processing steps (median and gaussian filters). Furthermore, specimen influence on the resolution was studied (the influence of embedding medium, coverglass thickness, and depth below the coverglass). Both lateral and axial resolutions are presented. The results clearly show that real objects are far from being points and that experimental resolution is often much worse than the theoretical one. Although the article concentrates on fluorescence imaging using high NA objectives, similar dependence can also be expected for other optical arrangements.

• MeSH
• DNA ultrastruktura   MeSH
• fluorescein-5-isothiokyanát MeSH
• fluorescenční barviva MeSH
• hybridizace in situ fluorescenční MeSH
• lidé MeSH
• mikrosféry MeSH
• mikroskopie * přístrojové vybavení   metody   MeSH
• počítačové zpracování obrazu MeSH
• senzitivita a specificita MeSH
• teoretické modely MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH
• fluorescein-5-isothiokyanát MeSH
• fluorescenční barviva MeSH

Fluorescence light microscopy provided convincing evidence for the domain organization of plant plasma membrane (PM) proteins. Both peripheral and integral PM proteins show an inhomogeneous distribution within the PM. However, the size of PM nanodomains and protein clusters is too small to accurately determine their dimensions and nano-organization using routine confocal fluorescence microscopy and super-resolution methods. To overcome this limitation, we have developed a novel correlative light electron microscopy method (CLEM) using total internal reflection fluorescence microscopy (TIRFM) and advanced environmental scanning electron microscopy (A-ESEM). Using this technique, we determined the number of auxin efflux carriers from the PINFORMED (PIN) family (NtPIN3b-GFP) within PM nanodomains of tobacco cell PM ghosts. Protoplasts were attached to coverslips and immunostained with anti-GFP primary antibody and secondary antibody conjugated to fluorochrome and gold nanoparticles. After imaging the nanodomains within the PM with TIRFM, the samples were imaged with A-ESEM without further processing, and quantification of the average number of molecules within the nanodomain was performed. Without requiring any post-fixation and coating procedures, this method allows to study details of the organization of auxin carriers and other plant PM proteins.

• Klíčová slova
• auxin carriers, correlative microscopy, nanodomains, plasma membrane,
• MeSH
• Arabidopsis genetika   růst a vývoj   MeSH
• buněčná membrána genetika   metabolismus   ultrastruktura   MeSH
• konfokální mikroskopie MeSH
• kovové nanočástice chemie   MeSH
• kyseliny indoloctové metabolismus   MeSH
• mikroskopie elektronová rastrovací * MeSH
• počítačové zpracování obrazu MeSH
• protoplasty metabolismus   ultrastruktura   MeSH
• regulátory růstu rostlin genetika   metabolismus   MeSH
• tabák genetika   metabolismus   ultrastruktura   MeSH
• zlato chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyseliny indoloctové MeSH
• regulátory růstu rostlin MeSH
• zlato MeSH