This research introduces a novel approach by incorporating various types of gelatins, including bovine, porcine, and fish skin, into polycaprolactone and poly (lactic-co-glycolic acid) using a solvent casting method. The films are evaluated for morphology, mechanical properties, thermal stability, biodegradability, hemocompatibility, cell adhesion, proliferation, and cytotoxicity. The results show that the incorporation of gelatins into the films alters their mechanical properties, with a decrease in tensile strength but an increase in elongation at break. This indicates that the films become more flexible with the addition of gelatin. Gelatin incorporation has a limited effect on the thermal stability of the films. The composites with the gelatin show higher biodegradability with the highest weight loss in the case of fish gelatin. The films exhibit high hemocompatibility with minimal hemolysis observed. The gelatin has a dynamic effect on cell behavior and promotes long-term cell proliferation. In addition, all composite films reveal exceptionally low levels of cytotoxicity. The combination of the evaluated parameters shows the appropriate level of biocompatibility for gelatin-based samples. These findings provide valuable insights for future studies involving gelatin incorporation in tissue engineering applications.
- Publikační typ
- časopisecké články MeSH
Decellularized tissue is an important source for biological tissue engineering. Evaluation of the quality of decellularized tissue is performed using scanned images of hematoxylin-eosin stained (H&E) tissue sections and is usually dependent on the observer. The first step in creating a tool for the assessment of the quality of the liver scaffold without observer bias is the automatic segmentation of the whole slide image into three classes: the background, intralobular area, and extralobular area. Such segmentation enables to perform the texture analysis in the intralobular area of the liver scaffold, which is crucial part in the recellularization procedure. Existing semi-automatic methods for general segmentation (i.e., thresholding, watershed, etc.) do not meet the quality requirements. Moreover, there are no methods available to solve this task automatically. Given the low amount of training data, we proposed a two-stage method. The first stage is based on classification of simple hand-crafted descriptors of the pixels and their neighborhoods. This method is trained on partially annotated data. Its outputs are used for training of the second-stage approach, which is based on a convolutional neural network (CNN). Our architecture inspired by U-Net reaches very promising results, despite a very low amount of the training data. We provide qualitative and quantitative data for both stages. With the best training setup, we reach 90.70% recognition accuracy.
Increased activity of the sympathetic nervous system (SNS) has been proposed as a risk factor for increased cardiovascular mortality in patients with chronic kidney disease (CKD). Information on the activity of cardiac sympathetic innervation is non-homogeneous and incomplete. The aim of our study was to evaluate the tonic effect of SNS on heart rate, norepinephrine turnover and direct and indirect effects of norepinephrine in left ventricles of subtotally nephrectomized rats (SNX) in comparison with sham-operated animals (SHAM). Renal failure was verified by measuring serum creatinine and urea levels. SNX rats developed increased heart rates and blood pressure (BP). The increase in heart rate was not caused by sympathetic overactivity as the negative chronotropic effect of metipranolol did not differ between the SNX and SHAM animals. The positive inotropic effects of norepinephrine and tyramine on papillary muscle were not significantly different. Norepinephrine turnover was measured after the administration of tyrosine hydroxylase inhibitor, pargyline, tyramine, desipramine, and KCl induced depolarization. The absolute amount of released norepinephrine was comparable in both groups despite a significantly decreased norepinephrine concentration in the cardiac tissue of the SNX rats. We conclude that CKD associated with renal denervation in rats led to adaptive changes characterized by an increased reuptake and intracellular norepinephrine turnover which maintained normal reactivity of the heart to sympathetic stimulation.
- MeSH
- chronická renální insuficience komplikace metabolismus patofyziologie MeSH
- kardiovaskulární nemoci etiologie MeSH
- ledviny metabolismus MeSH
- modely nemocí na zvířatech MeSH
- nefrektomie MeSH
- neuropeptid Y metabolismus MeSH
- noradrenalin krev MeSH
- peptid spojený s genem pro kalcitonin metabolismus MeSH
- potkani Wistar MeSH
- srdeční frekvence MeSH
- srdeční komory metabolismus patofyziologie MeSH
- sympatický nervový systém patofyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: The pig is one of the most valuable in vivo models in biomedical research, however with only a few well-accessible veins suitable for venipuncture. Moreover, most of the known methods of blood collection are suitable only for a limited time period. The aim of the study was to verify an improved method of long-term catheterization of the jugular vein in pigs. METHODS: A 420 mm polyurethane catheter 16G tube was surgically inserted using the Seldinger technique. The part of the tube that was not inserted into the vein was threaded through a subcutaneously introduced trocar into the occipital area, where it was well accessible and well protected from damage. The catheters were flushed with sterile 0.9% saline solution and locked with 4% citrate between frequent blood samplings, or with 30% citrate at intervals of 1-2-days. Once a week, the catheters were locked with 4% citrate containing taurolidine for 24 h in order to prevent infection. The method was verified in 14 pigs. RESULTS: The catheters were fully functional for up to 11 weeks and no infection or thrombus was observed. DISCUSSION: This method of catheterization and catheter care allows the realization of long-term experiments with comfortable and stress-free blood sampling.
- MeSH
- katetrizace metody MeSH
- odběr vzorku krve metody MeSH
- prasata MeSH
- taurin aplikace a dávkování analogy a deriváty MeSH
- thiadiaziny aplikace a dávkování MeSH
- venae jugulares chirurgie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- abstrakt z konference MeSH
Studie se zaměřuje na hodnocení účinku opakované expozice HBO na mitochondriální respiraci lidských fetálních plicních fibroblastů (HFL1). Mitochondriální spotřeba kyslíku byla hodnocena metodou high-resolution respirometry (HRR), životaschopnost buněk hodnocena PrestoBlue®, morfologie analyzovaná rutinní fluorescenční mikroskopií a fázovým kontrastem a byla zhodnocena aktivita superoxid dismutázy (SOD) a citrát syntázy (CS). Buňky byly vystaveny HBO (3ATA) 2 hodiny denně po dobu 5 po sobě jdoucích dní. Den po poslední HBO expozici vykazovaly buňky podstatně menší plochu a obvod, sníženou životaschopnost a zvýšenou aktivitu SOD. Nebyly zjištěny žádné změny v aktivitě CS ani v kvalitě mitochondriální sítě. HRR odhalila sníženou mitochondriální spotřebu kyslíku, která se projevila snížením aktivity komplexu II a sníženou spotřebou kyslíku při oxidací mastných kyselin. Naše zjištění dokládají, že v podmínkách napodobujících intermitentní expozici HBO, trpí plicní fibroblasty zhoršenou mitochondriální respirací spojenou s komplexem II a poruchou buněčného růstu i při zvýšené antioxidační obraně. Mechanismus této HBO-indukované mitochondriální dysfunkce je nutné hlouběji prozkoumat.
Study aims to evaluate effects of repeated exposure to HBO on mitochondrial respiration assessed by high-resolution respirometry (HRR), cell viability estimated by PrestoBlue® reaction, morphology analyzed by routine phase contrast and fluorescent microscopy, and superoxide dismutase (SOD) and citrate synthase (CS) activities using human lung fibroblasts. The cells were exposed to HBO (3 ATA) for 2 hours per day for 5 consecutive days. One day after the last exposure, HBO cells displayed significantly smaller area and perimeter, compromised viability and elevated SOD activity. No changes were detected in CS activity or quality of mitochondrial network. HRR revealed impaired mitochondrial oxygen consumption manifested by increased leak respiration, decreased activity of complex II and compromised ATP-related oxygen consumption when fatty acids were oxidized. Our findings document that in conditions mimicking chronic intermittent exposure to HBO, lung fibroblasts suffer from compromised mitochondrial respiration linked to complex II and impaired cellular growth in spite of increased antioxidant defense. Underlying mechanism of this HBO-induced mitochondrial dysfunction should be further explored.
- Klíčová slova
- respirometrie,
- MeSH
- buněčné dýchání MeSH
- fibroblasty * enzymologie metabolismus MeSH
- fluorescenční mikroskopie MeSH
- hyperbarická oxygenace * škodlivé účinky MeSH
- hyperoxie MeSH
- lidé MeSH
- mitochondrie MeSH
- plíce anatomie a histologie MeSH
- plod MeSH
- superoxiddismutasa MeSH
- techniky in vitro MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Hyperbaric oxygen (HBO) therapy, i.e. breathing pure oxygen under increased environmental pressures serves as a treatment for diverse medical conditions. However, elevated oxygen concentration can be detrimental to central nervous system or lungs. Our study aimed to evaluate the effects of repeated exposure to HBO on mitochondrial respiration assessed by high-resolution respirometry (HRR), cell viability estimated by PrestoBlue® reaction, morphology analyzed by routine phase contrast and fluorescent microscopy, and superoxide dismutase (SOD) and citrate synthase (CS) activities using human lung fibroblasts. The cells were exposed to HBO for 2 h per day for 5 consecutive days. One day after the last exposure, HBO cells displayed significantly smaller area and perimeter, compromised viability and elevated SOD activity. No changes were detected in CS activity or quality of mitochondrial network. HRR revealed impaired mitochondrial oxygen consumption manifested by increased leak respiration, decreased activity of complex II and compromised ATP-related oxygen consumption when fatty acids were oxidized. Our findings document that in conditions mimicking chronic intermittent exposure to HBO, lung fibroblasts suffer from compromised mitochondrial respiration linked to complex II and impaired cellular growth in spite of increased antioxidant defense. Underlying mechanism of this HBO-induced mitochondrial dysfunction should be further explored.
- MeSH
- buněčné dýchání fyziologie MeSH
- buněčné linie MeSH
- fibroblasty metabolismus MeSH
- hyperbarická oxygenace škodlivé účinky MeSH
- lidé MeSH
- mitochondrie fyziologie MeSH
- oxidační stres fyziologie MeSH
- plíce cytologie metabolismus MeSH
- spotřeba kyslíku fyziologie MeSH
- viabilita buněk fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Ample experimental evidence suggests that sepsis could interfere with any mitochondrial function; however, the true role of mitochondrial dysfunction in the pathogenesis of sepsis-induced multiple organ dysfunction is still a matter of controversy. This review is primarily focused on mitochondrial oxygen consumption in various animal models of sepsis in relation to human disease and potential sources of variability in experimental results documenting decrease, increase or no change in mitochondrial respiration in various organs and species. To date, at least three possible explanations of sepsis-associated dysfunction of the mitochondrial respiratory system and consequently impaired energy production have been suggested: 1. Mitochondrial dysfunction is secondary to tissue hypoxia. 2. Mitochondria are challenged by various toxins or mediators of inflammation that impair oxygen utilization (cytopathic hypoxia). 3. Compromised mitochondrial respiration could be an active measure of survival strategy resembling stunning or hibernation. To reveal the true role of mitochondria in sepsis, sources of variability of experimental results based on animal species, models of sepsis, organs studied, or analytical approaches should be identified and minimized by the use of appropriate experimental models resembling human sepsis, wider use of larger animal species in preclinical studies, more detailed mapping of interspecies differences and organ-specific features of oxygen utilization in addition to use of complex and standardized protocols evaluating mitochondrial respiration.
- MeSH
- buněčné dýchání fyziologie MeSH
- hypoxie buňky fyziologie MeSH
- lidé MeSH
- mitochondrie metabolismus patologie MeSH
- multiorgánové selhání metabolismus patologie MeSH
- sepse metabolismus patologie MeSH
- spotřeba kyslíku fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Autoři podávají přehled o incidenci, diagnostice a léčbě akutních otrav oxidem uhelnatým (dále jen CO). Otrav sice po ukončení dodávky svítiplynu do distribuční městské sítě významně ubylo ve srovnání s minulostí, ale o to méně se na možnost této diagnózy ve zdravotnickém zařízení pomýšlí. Lehčí stupně otrav oxidem uhelnatým se totiž vyznačují velmi nespecifickou symptomatologií, takže při němé anamnéze pobytu postiženého v zamořeném ovzduší, především pak v uzavřeném prostoru (např. garáž s výfukovými plyny, kouř při hoření různých látek, průmyslové plyny), není diagnóza vždy snadná. Otravy s poruchou vědomí mohou napodobovat jiné chorobné stavy, především pak postižení CNS ve smyslu cévní mozkové příhody. Autoři doporučují léčbu hyperbaroxií, tj. podávání kyslíku v přetlaku, což je léčba kauzální, nejrychlejší a nejúčinnější. Většina postižených má zachráněný nejen život samotný, ale i jeho původní kvalitu. Pouze otravy nejtěžšího stupně mají jednak 20% mortalitu (při celkové mortalitě 2–3 %), jednak po přežití mohou přetrvávat posthypoxické komplikace, s manifestací nejčastěji neuropsychickou nebo kardiální. Kvalitativně nižší stupeň léčby je podávání 100% medicinálního kyslíku normobaricky, což představuje zejména u nejtěžších otrav léčbu méně účinnou, s hrozícími následnými komplikacemi invalidizujícího charakteru.
The authors review incidence, diagnostics and treatment of acute carbon monoxide (CM) intoxications. In the era after urban usage of coalgas has been terminated, the CM intoxications are much less frequent – therefore being sometimes omitted in the diagnostics process. Lighter CM intoxications show very unspecific symptoms and without known history of a subjekt's presence in an intoxicated area (e. g. garage filled with exhaust gas, smoke from burning substances, industrial gas) the diagnose is not easy. Intoxications with unconsciousness can simulate other states, especially vascular CNS damage. Authors recommend hyperbaroxic treatment (administration of hyperbaric oxygen) which is causal, the fastest and the most effective. In most cases not only life of the patient is saved but also his former quality. Only the highest degree intoxications have 20% mortality (the overall mortality being 2–3%) and posthypoxic complications (mostly neuropsychic or cardial). Administration of 100% normobaric oxygen only is a lesser option, which is, especially in higher degree intoxications, less effective approach with a risk of subsequent invalidizing complications.
- MeSH
- bezpečnost MeSH
- hygiena práce MeSH
- hyperbarická oxygenace přístrojové vybavení využití MeSH
- lidé MeSH
- mladiství MeSH
- otrava oxidem uhelnatým * diagnóza etiologie terapie MeSH
- oxid uhelnatý škodlivé účinky MeSH
- příznaky a symptomy MeSH
- senioři MeSH
- statistika jako téma MeSH
- stupeň závažnosti nemoci MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
