SEM image analysis
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In the presented study, the cells of the glacial alga Ancylonema alaskanum collected in the Austrian Alps were analyzed. Algae were imaged both in their natural environment and in laboratory conditions using transmitted light and fluorescence microscopy. Using appropriate fluorochromes, the cell wall and cell organelles were studied. Oval nuclei located in the middle of the cell next to the chloroplasts and active mitochondria as well as lipid thylakoids of chloroplasts were imaged. Scanning electron microscopy showed that the surface of the algal cell wall was not significantly differentiated, and atomic force microscope imaging recorded little roughness. The SEM EDS analysis revealed that carbon, nitrogen, oxygen, and magnesium were the main components of the cells. It is worth emphasizing that the analyzed living algal cells were obtained directly from the glacier surface and demonstrated normal respiratory processes i.e. undisturbed physiological functions. Additionally, the mineral material accompanying the cells in their natural environment - fragments of the rock were imaged by Differential Interference Contrast microscopy and analyzed by Fourier Transform Infrared Spectroscopy. The study provides new data on the morphology and physicochemical characteristics of A. alaskanum, contributing to a more comprehensive characterization of their place in this harsh ecosystem.
- MeSH
- ledový příkrov * MeSH
- mikroskopie elektronová rastrovací MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rakousko MeSH
Many photosensitive substances suitable for photodynamic therapy (PDT) have limited applications due to their insufficient solubility in polar solvents. Our research overcomes this challenge by means of nanotechnology in order to transform hydrophobic compounds into stable aqueous solutions, enabling them to use their full potential and unique properties in cancer therapy. In this study, the novel nano-composite cGQDs-PEG-curcumin was developed to overcome the insolubility of curcumin in water and its extraordinary efficacy in PDT was evaluated. Complex characterization was performed using high-resolution transmission electron microscopy (HR-TEM), FTIR, and UV-Vis spectroscopy. Further analysis involved fluorescence lifetime imaging (FLIM), and its cellular localization was mapped with confocal microscopy. In order to evaluate PDT effectiveness, cells treated with cGQDs-PEG-curcumin were irradiated with 5 J/cm2 of 414 nm light. After irradiation, cell viability assay, scanning electron microscopy (SEM), reactive oxygen species (ROS) detection, comet assay, and γH2AX-based DNA double-strand breaks (DSBs) detection were assessed and revealed a remarkable ability of the nano-composite to induce DNA damage after irradiation without ROS production. Our findings highlight the potential of cGQDs-PEG-curcumin as a cutting-edge PDT agent, capable of disrupting cell membrane and nucleolar integrity and impairing ribosomal synthesis, which is crucial for proliferating tumour cells.
- MeSH
- buněčné jadérko * účinky léků metabolismus MeSH
- dvouřetězcové zlomy DNA účinky léků MeSH
- fotochemoterapie * metody MeSH
- fotosenzibilizující látky * farmakologie MeSH
- grafit * chemie farmakologie MeSH
- kurkumin * farmakologie chemie MeSH
- kvantové tečky * chemie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory * farmakoterapie MeSH
- polyethylenglykoly * chemie farmakologie MeSH
- poškození DNA * účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: Subretinal (SR) injection in porcine models is a promising avenue for preclinical evaluation of cell and gene therapies. Targeting of the subretinal fluid compartment (bleb) is critical to the procedure, especially if treatment of the cone-rich area centralis is required (i.e., visual streak [VS] in pigs). To our knowledge, this study is the first to investigate the influence of injection site placement on VS involvement in the pig eye. METHODS: We performed 23-gauge pars plana vitrectomy followed by SR injection in 41 eyes of 21 animals (Sus scrofa domesticus). In 27 eyes (65.9%), the injection site was placed superior to the VS, and in 14 eyes (34.1%) it was placed inferior to it. Using intraoperative imaging, blebs were classified based on their propagation behavior relative to the VS. RESULTS: In 79% of cases, blebs from inferior injection sites developed away from the VS, exhibiting a mean ± SEM vertical anisotropy (AP) of 0.67 ± 0.11. In contrast, blebs from superior injection sites tended to develop toward the VS with an AP of 1.27 ± 0.18 (P = 0.0070). Blebs developed away from the VS in only 41% of injections (P = 0.0212). Inferior blebs were orientated close to 0° (horizontal), whereas superior blebs displayed varied orientations with a mean angle of 56° (P = 0.0008). CONCLUSIONS: Bleb propagation was anisotropic (i.e., directionally biased) and dependent on injection site placement. Superior injection sites led to superior VS detachment. Morphological analysis suggested increased adhesion forces at the VS and superior vascular arcades. This study will aid the planning of surgeries for targeted subretinal delivery in pig models.
The bioprinting of high-concentrated collagen bioinks is a promising technology for tissue engineering and regenerative medicine. Collagen is a widely used biomaterial for bioprinting because of its natural abundance in the extracellular matrix of many tissues and its biocompatibility. High-concentrated collagen hydrogels have shown great potential in tissue engineering due to their favorable mechanical and structural properties. However, achieving high cell proliferation rates within these hydrogels remains a challenge. In static cultivation, the volume of the culture medium is changed once every few days. Thus, perfect perfusion is not achieved due to the relative increase in metabolic concentration and no medium flow. Therefore, in our work, we developed a culture system in which printed collagen bioinks (collagen concentration in hydrogels of 20 and 30 mg/mL with a final concentration of 10 and 15 mg/mL in bioink) where samples flow freely in the culture medium, thus enhancing the elimination of nutrients and metabolites of cells. Cell viability, morphology, and metabolic activity (MTT tests) were analyzed on collagen hydrogels with a collagen concentration of 20 and 30 mg/mL in static culture groups without medium exchange and with active medium perfusion; the influence of pure growth culture medium and smooth muscle cells differentiation medium was next investigated. Collagen isolated from porcine skins was used; every batch was titrated to optimize the pH of the resulting collagen to minimize the difference in production batches and, therefore, the results. Active medium perfusion significantly improved cell viability and activity in the high-concentrated gel, which, to date, is the most limiting factor for using these hydrogels. In addition, based on SEM images and geometry analysis, the cells remodel collagen material to their extracellular matrix.
- Publikační typ
- časopisecké články MeSH
Testing the hemocompatibility of medical devices after their interaction with blood entails the need to evaluate the activation of blood elements and the degree of their coagulation and adhesion to the device surface. One possible way to achieve this is to use scanning electron microscopy (SEM). The aim was to develop a novel SEM-based method to assess the thrombogenic potential of medical devices and their adhesiveness to blood cells. As a part of this task, also find a convenient procedure of efficient and non-destructive sample fixation for SEM while reducing the use of highly toxic substances and shortening the fixation time. A polymeric surgical mesh was exposed to blood so that blood elements adhered to its surface. Such prepared samples were then chemically fixed for a subsequent SEM measurement; a number of fixation procedures were tested to find the optimal one. The fixation results were evaluated from SEM images, and the degree of blood elements' adhesion was determined from the images using ImageJ software. The best fixation was achieved with the May-Grünwald solution, which is less toxic than chemicals traditionally used. Moreover, manipulation with highly toxic osmium tetroxide can be avoided in the proposed procedure. A convenient methodology for SEM image analysis has been developed too, enabling to quantitatively evaluate the interaction of blood with the surfaces of various medical devices. Our method replaces the subjective assessment of surface coverage with a better-defined procedure, thus offering more precise and reliable results.
- MeSH
- histologické techniky * MeSH
- mikroskopie elektronová rastrovací MeSH
- oxid osmičelý * MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Understanding the formation of body image is critical for the prevention and treatment of eating disorders, especially in adolescence, when body image develops significantly. One of the important facets of body image is body appreciation, which consists of positive feelings and attitudes towards the body regardless of its perceived "flaws". To measure body appreciation, Body Appreciation Scale-2 (Tylka and Wood-Barcalow in Body Image 12:53-67, 2015a), a unidimensional 10-item measure, has been developed and routinely used in body image research. The current study examined the validity (i.e., factor structure, gender and age invariance, associations with other constructs) of the Czech version of Body Appreciation Scale-2 for adolescents. METHODS: The study used two large samples of Czech adolescents, aged 13-18 (N1 = 613, M = 15.5, 52% girls; N2 = 1,530, M = 15.4, 50% girls). The data were collected in August 2021 (N1) and November 2020 (N2) through an online survey. For the data analysis, we used confirmatory factor analysis (CFA), multi-group confirmatory factor analysis (MG-CFA), and Structural Equation Modeling (SEM). RESULTS: Our findings supported the proposed unidimensional factor structure and the gender (i.e., girls, boys) and age (i.e., 13-15, 16-18) scalar invariance of the Czech version of Body Appreciation Scale-2. The data also showed the expected positive correlations with body satisfaction and self-esteem, and negative correlations with media-ideal internalization, appearance schematicity, and depression. Furthermore, we discovered that body appreciation was more strongly connected to media-ideal internalization and depression for girls than boys. CONCLUSIONS: The present study provided robust evidence that supports the validity of the Czech version of Body Appreciation Scale-2 and its usability for the assessment of body appreciation in Czech adolescents. We also proposed future directions for the research on body appreciation based on the explored gender differences.
- Publikační typ
- časopisecké články MeSH
Illiosentis Van Cleave et Lincicome, 1939 initially included two species: Illiosentis furcatus Van Cleave et Lincicome, 1939 found in the West Atlantic from Cape Cod in Massachusetts, USA to northern Argentina and Illiosentis cetratus Van Cleave, 1945 with restricted distribution in the Pacific coast of southern California. We are reporting I. furcatus from Peru for the first time and describe a population of I. cetratus from the California corbina, Menticirrhus undulatus (Girard), from southern California. The proboscis hook formula was 14 longitudinal rows for I. furcatus of 18-23 hooks each compared to 16 rows of 19-24 hooks each reported by Van Cleave (1945). We complete the inadequate description of I. cetratus with new information on sexual differentiation in the length of the trunk, dorsal vs. ventral hooks, hook roots, trunk spines, two types of anterior recurved rooted hooks vs. posterior rootless straight hooks, measurements of dorsal and ventral hooks and spines, shape of hook roots, terminal position of the female gonopore, and of position of the cephalic ganglion at the anterior margin of the trunk. We also include new details of the reproductive system in both sexes including Saefftigen's pouch and cement gland ducts. We present new SEM and light microscope images. The Energy Dispersive X-ray analysis (EDXA) shows a high level of sulfur in anterior, middle and posterior hooks in various hook sites, as well as spectra of hook tips with a higher relative concentration of sulfur compared to other hook sites. For the placement of I. cetratus, phylogenetic analysis of sequences of three molecular markers, 18S, 28S rRNA and mitochondrial cox 1 genes, was performed with other related available sequences. The resulting analysis illustrated that I. cetratus was nested within a separate clade along with species of two genera, Dentitruncus truttae Sinzar, 1955 and Neotegorhynchus cyprini Lisitsyna, Xi, Orosová, Barčák et Oros, 2022 represented our species of Illiosentis separate from species of Tegorhynchus Van Cleave, 1921 (as also according to the morphology) with which the Illiosentis species were previously synonymised.
- MeSH
- Acanthocephala * anatomie a histologie MeSH
- fylogeneze MeSH
- helmintózy zvířat * epidemiologie MeSH
- nemoci ryb * epidemiologie MeSH
- Perciformes * MeSH
- síra MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Peru MeSH
U zdravých jedinců jsou kosterní svaly největší tkání v těle (30–40 % celkové tělesné hmotnosti) a jsou v nich uloženy tři čtvrtiny všech tělesných proteinů. Změny svalové soustavy, zejména ve smyslu snížení svalové hmoty a funkce, významně ovlivňují prognózu a průběh řady chronických onemocnění, včetně chronických onemocnění jater. Jejich přítomnost je asociována s vyšší morbiditou, mortalitou a horší kvalitou života pacientů. K popisu změn svalové tkáně jsou používány pojmy sarkopenie, myosteatóza a s poruchou svalstva úzce souvisí i komplexnější pojem „frailty“, syndrom křehkosti. Sarkopenie je definována jako snížení množství svalové hmoty a/nebo svalové funkce, k diagnostice se nejčastěji používá stanovení tzv. skeletal muscle index (SMI) na úrovni třetího lumbálního obratle (L3) dle CT. Myosteatóza je definována jako přítomnost tuku ve svalech jak intramyocelulárně, tak intermyocelulárně a je diagnostikována na základě stanovení denzity svalů na CT v úrovni L3 (skeletal muscle radiation attenuation – SM-RA). Syndrom křehkosti (frailty) zahrnuje kromě změn svalové tkáně a poklesu schopnosti pohybu i změny dalších orgánových systémů, jejichž důsledkem je snížení rezerv organizmu a vyšší riziko nepříznivého průběhu onemocnění. K diagnostice se využívají různé skórovací systémy, např. Fried Frailty Index nebo modifikovaný Liver Frailty Index (LFI) u pacientů s jaterní cirhózou. Základem léčby pacientů s poruchami svalové tkáně je léčba základního onemocnění (včetně transplantace jater u pokročilé cirhózy), zlepšení výživy, dostatečná fyzická aktivita a léčba eventuálního deficitu vitaminu D. V tomto přehledovém článku shrnujeme aktuální pohled na patofyziologii, diagnostiku a léčbu sarkopenie, myosteatózy a syndromu křehkosti u pacientů s jaterní cirhózou.
Skeletal muscles are the biggest tissue in healthy people (30–40% of total body mass) and they comprise three quarters of total body proteins. Muscle alterations, especially muscle wasting and loss of muscle function, have an indisputable prognostic value in the outcome of chronic diseases, including chronic liver diseases. Muscle wasting is associated with higher morbidity, mortality and poor quality of life. The terms sarcopenia and myosteatosis are used to describe specific muscle alterations, both forming substantial components of multidimensional construct “frailty syndrome”. Sarcopenia is defined as loss of muscle mass and/or loss of muscle function. It is usually diagnosed using the skeletal muscle index from computed tomography (CT) image analysis at the L3 vertebra. Myosteatosis is defined as an excess intramyocelullar and intermyocellular fat deposition. Diagnosis of myosteatosis is based on a measurement of skeletal muscle density by CT imaging at the L3 vertebra (skeletal muscle radiation attenuation – SM-RA). Besides muscle alterations and decreased physical performance, frailty syndrome also comprises changes of other organ systems, leading to the loss of functional reserves and higher vulnerability. Different scoring systems, such as Fried Frailty Index (FFI) or modified Liver Frailty Index (LFI) for patients with liver cirrhosis, are used to diagnose patients with frail phenotype. The principle of the treatment of patients with muscle alterations is therapy of liver disease (including liver transplant in advanced cirrhosis), improvement of the nutritional status, adequate physical activity and supplementation of vitamin D deficiency, if necessary. In this review, we summarize up-to-date knowledge about pathophysiology, diagnostic tools and treatment options of sarcopenia, myosteatosis and frailty syndrome in patients with liver cirrhosis
- Klíčová slova
- myosteatóza, syndrom křehkosti,
- MeSH
- jaterní cirhóza * komplikace MeSH
- lidé MeSH
- sarkopenie * etiologie patofyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
More than half of the hospital-associated infections worldwide are related to the adhesion of bacteria cells to biomedical devices and implants. To prevent these infections, it is crucial to modify biomaterial surfaces to develop the antibacterial property. In this study, chitosan (CS) and chondroitin sulfate (ChS) were chosen as antibacterial coating materials on polylactic acid (PLA) surfaces. Plasma-treated PLA surfaces were coated with CS either direct coating method or the carbodiimide coupling method. As a next step for the combined saccharide coating, CS grafted samples were immersed in ChS solution, which resulted in the polyelectrolyte complex (PEC) formation. Also in this experiment, to test the drug loading and releasing efficiency of the thin film coatings, CS grafted samples were immersed into lomefloxacin-containing ChS solution. The successful modifications were confirmed by elemental composition analysis (XPS), surface topography images (SEM), and hydrophilicity change (contact angle measurements). The carbodiimide coupling resulted in higher CS grafting on the PLA surface. The coatings with the PEC formation between CS-ChS showed improved activity against the bacteria strains than the separate coatings. Moreover, these interactions increased the lomefloxacin amount adhered to the film coatings and extended the drug release profile. Finally, the zone of inhibition test confirmed that the CS-ChS coating showed a contact killing mechanism while drug-loaded films have a dual killing mechanism, which includes contact, and release killing.
BACKGROUND: Cholinergic deficit and medial temporal lobe (MTL) atrophy are hallmarks of Alzheimer's disease (AD) leading to early allocentric spatial navigation (aSN) impairment. APOEɛ4 allele (E4) is a major genetic risk factor for late-onset AD and contributes to cholinergic dysfunction. Basal forebrain (BF) nuclei, the major source of acetylcholine, project into multiple brain regions and, along with MTL and prefrontal cortex (PFC), are involved in aSN processing. OBJECTIVE: We aimed to determine different contributions of individual BF nuclei atrophy to aSN in E4 positive and E4 negative older adults without dementia and assess whether they operate on aSN through MTL and PFC or independently from these structures. METHODS: 120 participants (60 E4 positive, 60 E4 negative) from the Czech Brain Aging Study underwent structural MRI and aSN testing in real-space arena setting. Hippocampal and BF nuclei volumes and entorhinal cortex and PFC thickness were obtained. Associations between brain regions involved in aSN were assessed using MANOVA and complex model of mutual relationships was built using structural equation modelling (SEM). RESULTS: Path analysis based on SEM modeling revealed that BF Ch1-2, Ch4p, and Ch4ai nuclei volumes were indirectly associated with aSN performance through MTL (pch1 - 2 = 0.039; pch4p = 0.042) and PFC (pch4ai = 0.044). In the E4 negative group, aSN was indirectly associated with Ch1-2 nuclei volumes (p = 0.015), while in the E4 positive group, there was indirect effect of Ch4p nucleus (p = 0.035). CONCLUSION: Our findings suggest that in older adults without dementia, BF nuclei affect aSN processing indirectly, through MTL and PFC, and that APOE E4 moderates these associations.
- MeSH
- alely MeSH
- Alzheimerova nemoc * diagnostické zobrazování genetika MeSH
- atrofie MeSH
- cholinergní látky MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- pars basalis telencephali * diagnostické zobrazování MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
