This study was conducted to determine the effect of 1-stage homogenization (OSH) and 2-stage homogenization (TSH) and the addition of polysaccharides [κ-carrageenan (CR) or furcellaran (FR) at levels ranging from 0.000 to 1.000% (wt/wt)] on the physicochemical, viscoelastic, and mechanical vibration damping properties of processed cheese sauces (PCS) after 30 d of storage (6 ± 2°C). The basic chemical properties (pH, dry matter content) were similar for all tested samples. Viscoelastic measurements indicated that PCS rigidity was directly proportional to increasing CR or FR concentration and to the application of homogenization. The interactions between the application of homogenization and the concentration of polysaccharides used were also significant. Compared with OSH, TSH did not lead to any further increase in the rigidity. The preceding results were also supported by data obtained from a nondestructive method of mechanical vibration damping. No changes in water activity were observed in any PCS sample. Overall, the addition of FR or CR appeared to be highly suitable for increasing the emulsion stability of PCS. If PCS products with softer consistency are desired, then a concentration of CR/FR ≤0.250% (wt/wt) could be recommended together with OSH/TSH. For products for which a firmer PCS consistency is required, the addition of CR in concentrations of ≥0.500% (wt/wt) or FR in concentrations of ≥1.000% (wt/wt) together with OSH is recommended. Finally, as the concentration of polysaccharides increased, a darker PCS color was observed.

• MeSH
• karagenan MeSH
• manipulace s potravinami metody   MeSH
• polysacharidy MeSH
• reologie MeSH
• sýr * analýza   MeSH
• thyreotropin MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND AND AIMS: Brassica napus (AACC, 2n = 38, oilseed rape) is a relatively recent allotetraploid species derived from the putative progenitor diploid species Brassica rapa (AA, 2n = 20) and Brassica oleracea (CC, 2n = 18). To determine the influence of intensive breeding conditions on the evolution of its genome, we analysed structure and copy number of rDNA in 21 cultivars of B. napus, representative of genetic diversity. METHODS: We used next-generation sequencing genomic approaches, Southern blot hybridization, expression analysis and fluorescence in situ hybridization (FISH). Subgenome-specific sequences derived from rDNA intergenic spacers (IGS) were used as probes for identification of loci composition on chromosomes. KEY RESULTS: Most B. napus cultivars (18/21, 86 %) had more A-genome than C-genome rDNA copies. Three cultivars analysed by FISH ('Darmor', 'Yudal' and 'Asparagus kale') harboured the same number (12 per diploid set) of loci. In B. napus 'Darmor', the A-genome-specific rDNA probe hybridized to all 12 rDNA loci (eight on the A-genome and four on the C-genome) while the C-genome-specific probe showed weak signals on the C-genome loci only. Deep sequencing revealed high homogeneity of arrays suggesting that the C-genome genes were largely overwritten by the A-genome variants in B. napus 'Darmor'. In contrast, B. napus 'Yudal' showed a lack of gene conversion evidenced by additive inheritance of progenitor rDNA variants and highly localized hybridization signals of subgenome-specific probes on chromosomes. Brassica napus 'Asparagus kale' showed an intermediate pattern to 'Darmor' and 'Yudal'. At the expression level, most cultivars (95 %) exhibited stable A-genome nucleolar dominance while one cultivar ('Norin 9') showed co-dominance. CONCLUSIONS: The B. napus cultivars differ in the degree and direction of rDNA homogenization. The prevalent direction of gene conversion (towards the A-genome) correlates with the direction of expression dominance indicating that gene activity may be needed for interlocus gene conversion.

• MeSH
• Brassica napus genetika   MeSH
• genetická variace genetika   MeSH
• genetické lokusy genetika   MeSH
• genová konverze genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• ribozomální DNA genetika   MeSH
• Southernův blotting MeSH
• stanovení celkové genové exprese MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Publikační typ
• časopisecké články MeSH

Despite its negative impacts on the environment and biodiversity, tree plantations can contribute to biodiversity conservation in fragmented landscapes, as they harbor many native species. In this study, we investigated the impact of Eucalyptus plantations on the taxonomic and functional diversity of ant communities, comparing ant communities sampled in managed and unmanaged (abandoned for 28 years) Eucalyptus plantations, and native Atlantic rain forests. Eucalyptus plantations, both managed and unmanaged, reduced the functional diversity and increased the similarity between ant communities leading to functional homogenization. While communities in managed plantations had the lowest values of both taxonomic and functional ant diversities, ant communities from unmanaged plantations had similar values of species richness, functional redundancy and Rao's Q compared to ant communities from forest patches (although functional richness was lower). In addition, communities in unmanaged Eucalyptus plantations were taxonomically and functionally more similar to communities located in managed plantations, indicating that Eucalyptus plantations have a severe long-term impact on ant communities. These results indicate that natural regeneration may mitigate the impact of Eucalyptus management, particularly regarding the functional structure of the community (α diversity), although it does not attenuate the effects of long term homogenization in community composition (β diversity).

• MeSH
• biodiverzita * MeSH
• biologická variabilita populace * MeSH
• deštný prales MeSH
• Eucalyptus parazitologie   MeSH
• Formicidae klasifikace   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Introduction: Spinal cord (SC) pathology is strongly associated with disability in multiple sclerosis (MS). We aimed to evaluate the association between focal and diffuse SC abnormalities and spinal cord volume and to assess their contribution to physical disability in MS patients. Methods: This large sample-size cross-sectional study investigated 1,249 patients with heterogeneous MS phenotypes. Upper cervical-cord cross-sectional area (MUCCA) was calculated on an axial 3D-T2w-FatSat sequence acquired at 3T using a novel semiautomatic edge-finding tool. SC images were scored for the presence of sharply demarcated hyperintense areas (focal lesions) and homogenously increased signal intensity (diffuse changes). Patients were dichotomized according EDSS in groups with mild (EDSS up to 3.0) and moderate (EDSS ≥ 3.5) physical disability. Analysis of covariance was used to identify factors associated with dichotomized MUCCA. In binary logistic regression, the SC imaging parameters were entered in blocks to assess their individual contribution to risk of moderate disability. In order to assess the risk of combined SC damage in terms of atrophy and lesional pathology on disability, secondary analysis was carried out where patients were divided into four categories (SC phenotypes) according to median dichotomized MUCCA and presence/absence of focal and/or diffuse changes. Results: MUCCA was strongly associated with total intracranial volume, followed by presence of diffuse SC pathology, and disease duration. Compared to the reference group (normally appearing SC, MUCCA>median), patients with the most severe SC changes (SC affected with focal and/or diffuse lesions, MUCCA

• Publikační typ
• časopisecké články MeSH

Impaired myocardial bioenergetics is a hallmark of many cardiac diseases. There is a need of a simple and reproducible method of assessment of mitochondrial function from small human myocardial tissue samples. In this study we adopted high-resolution respirometry to homogenates of fresh human cardiac muscle and compare it with isolated mitochondria. We used atria resected during cardiac surgery (n = 18) and atria and left ventricles from brain-dead organ donors (n = 12). The protocol we developed consisting of two-step homogenization and exposure of 2.5% homogenate in a respirometer to sequential addition of 2.5 mM malate, 15 mM glutamate, 2.5 mM ADP, 10 μM cytochrome c, 10 mM succinate, 2.5 μM oligomycin, 1.5 μM FCCP, 3.5 μM rotenone, 4 μM antimycin and 1 mM KCN or 100 mM Sodium Azide. We found a linear dependency of oxygen consumption on oxygen concentration. This technique requires < 20 mg of myocardium and the preparation of the sample takes <20 min. Mitochondria in the homogenate, as compared to subsarcolemmal and interfibrillar isolated mitochondria, have comparable or better preserved integrity of outer mitochondrial membrane (increase of respiration after addition of cytochrome c is up to 11.7±1.8% vs. 15.7±3.1%, p˂0.05 and 11.7±3.5%, p = 0.99, resp.) and better efficiency of oxidative phosphorylation (Respiratory Control Ratio = 3.65±0.5 vs. 3.04±0.27, p˂0.01 and 2.65±0.17, p˂0.0001, resp.). Results are reproducible with coefficient of variation between two duplicate measurements ≤8% for all indices. We found that whereas atrial myocardium contains less mitochondria than the ventricle, atrial bioenergetic profiles are comparable to left ventricle. In conclusion, high resolution respirometry has been adapted to homogenates of human cardiac muscle and shown to be reliable and reproducible.

• MeSH
• citrátsynthasa metabolismus   MeSH
• dospělí MeSH
• energetický metabolismus MeSH
• kryoprezervace MeSH
• kyslík metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mastné kyseliny metabolismus   MeSH
• mitochondriální membrány metabolismus   MeSH
• oxidace-redukce MeSH
• senioři MeSH
• srdeční mitochondrie metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Photocatalytic degradation of pharmaceuticals (hydrocortisone, estradiol, and verapamil) and personal care product additives (parabens-methyl, ethyl, and propyl derivatives) was investigated in the homogeneous phase (with ferric ions as the catalyst) and on TiO2. Ferric ions in concentrations corresponding to concentrations in natural water bodies were shown to be a significant accelerator of the degradation in homogeneous reaction mixtures. In heterogeneous photocatalytic reactions on TiO2, lower reaction rates, but mineralisation to higher extents, were observed.

• MeSH
• estradiol chemie   MeSH
• fotolýza účinky záření   MeSH
• hydrokortison chemie   MeSH
• katalýza MeSH
• léčivé přípravky chemie   MeSH
• parabeny chemie   MeSH
• spektrofotometrie ultrafialová MeSH
• titan chemie   MeSH
• ultrafialové záření * MeSH
• verapamil chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

1. Glyceride biosynthesis from glycerol phosphate and [1-(14)C]palmitate was studied in liver homogenates of rats that were fed ad libitum or starved for 36-40hr. The changes in enzyme activity were related to total DNA content or total liver homogenate as these were found to be equivalent and to be the most meaningful parameters. 2. In liver homogenates from fed rats, labelled palmitate was incorporated mainly into phosphatidate (58% of the total incorporation into lipids), diglycerides (25%) and triglycerides (16%), whereas monoglycerides, cholesterol esters and phospholipids other than phosphatidate were labelled only to a small extent. Addition of particle-free supernatant to full homogenates increased the total incorporation of palmitate by 45% and the pattern of incorporation altered to 53% incorporated into triglycerides, 24% into diglycerides and 17% into phosphatidate. This result suggested that, in liver homogenates, phosphatidate phosphohydrolase (EC 3.1.3.4) may be rate-limiting in the biosynthesis of glycerides via the glycerol phosphate pathway. 3. Upon starvation, the amount of palmitate incorporated per liver into total phospholipids plus glycerides was decreased to between 68% and 75% of that observed with fed animals. In homogenates from fed animals 41-44% of the labelled phospholipids plus glycerides was in glycerides; this value increased to between 63% and 75% with starved rats. Of the palmitate incorporated into total phospholipids, between 85% and 86% was found in phosphatidate, independent of the nutritional state of the animal. The ratio of palmitate incorporated into triglycerides/diglycerides rose from 0.7, obtained with fed rats, to 1.0 with starved animals. 4. These results indicate that starvation caused a decrease in the activity (per total liver) of acyl-CoA-glycerol phosphate acyltransferase(s) (EC 2.3.1.15) and an increase in the activity of acyl-CoA-diglyceride acyltransferase (EC 2.3.1.20). The largest change, however, seemed to be related to the increased activity of the phosphatidate phosphohydrolase in the particle-free supernatant. 5. The latter enzyme was assayed in the particle-free supernatant with membrane-bound phosphatidate as substrate. In starvation, the activity per total liver was increased to between 130% and 190% and the specific activity to between 180% and 320% of the values for fed rats.

• MeSH
• acyltransferasy metabolismus   MeSH
• bezbuněčný systém MeSH
• cholesterol biosyntéza   MeSH
• DNA analýza   MeSH
• fosfatasy metabolismus   MeSH
• fosfolipidy * metabolismus   MeSH
• glyceridy * biosyntéza   MeSH
• glycerol metabolismus   MeSH
• hladovění * metabolismus   MeSH
• izotopy uhlíku MeSH
• játra * enzymologie   metabolismus   MeSH
• krysa rodu rattus MeSH
• kyseliny palmitové * metabolismus   MeSH
• techniky in vitro MeSH
• triglyceridy biosyntéza   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH

PURPOSE: The Tofts and the extended Tofts models are the pharmacokinetic models commonly used in dynamic contrast-enhanced MRI (DCE-MRI) perfusion analysis, although they do not provide two important biological markers, namely, the plasma flow and the permeability-surface area product. Estimates of such markers are possible using advanced pharmacokinetic models describing the vascular distribution phase, such as the tissue homogeneity model. However, the disadvantage of the advanced models lies in biased and uncertain estimates, especially when the estimates are computed voxelwise. The goal of this work is to improve the reliability of the estimates by including information from neighboring voxels. THEORY AND METHODS: Information from the neighboring voxels is incorporated in the estimation process through spatial regularization in the form of total variation. The spatial regularization is applied on five maps of perfusion parameters estimated using the tissue homogeneity model. Since the total variation is not differentiable, two proximal techniques of convex optimization are used to solve the problem numerically. RESULTS: The proposed algorithm helps to reduce noise in the estimated perfusion-parameter maps together with improving accuracy of the estimates. These conclusions are proved using a numerical phantom. In addition, experiments on real data show improved spatial consistency and readability of perfusion maps without considerable lowering of the quality of fit. CONCLUSION: The reliability of the DCE-MRI perfusion analysis using the tissue homogeneity model can be improved by employing spatial regularization. The proposed utilization of modern optimization techniques implies only slightly higher computational costs compared to the standard approach without spatial regularization.

• MeSH
• algoritmy MeSH
• fantomy radiodiagnostické MeSH
• glioblastom diagnostické zobrazování   MeSH
• kontrastní látky farmakologie   MeSH
• krysa rodu rattus MeSH
• magnetická rezonanční tomografie * MeSH
• mozek diagnostické zobrazování   MeSH
• nádory mozku diagnostické zobrazování   MeSH
• perfuze MeSH
• permeabilita MeSH
• počítačová simulace MeSH
• počítačové zpracování obrazu MeSH
• poměr signál - šum MeSH
• reprodukovatelnost výsledků MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Using skeletal muscle homogenates for respirometry has many advantages, but the main challenge is avoiding the damage to outer mitochondrial membrane (OMM) and complex I. By optimising the amount of muscle and careful titration of substrates and inhibitors we developed a new protocol and compared it to isolated mitochondria. We found acceptable damage to OMM (~10-15% increment of oxygen flux after addition of cytochrome c) and to complex I (~70% of electron flux). Homogenate retained ~90% of phosphorylation capacity of isolated mitochondria. The use of fresh homogenate was crucial as mitochondrial function declined rapidly after 2-3h of cold storage.

• MeSH
• buněčné dýchání * MeSH
• buněčné extrakty MeSH
• cytologické techniky metody   MeSH
• dospělí MeSH
• jehlová biopsie MeSH
• kosterní svaly fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mitochondriální nemoci diagnóza   MeSH
• mitochondrie fyziologie   MeSH
• odběr biologického vzorku metody   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The glycosidases within GH5-23 cleave the glycosidic bond of β-glucosylated or rutinosylated flavonoids. Moreover, by virtue of their transglycosylation activity, glycoconjugates with glucosyl and rutinosyl moieties are accessible. Here we report the biochemical characterization and biotechnological assessment of two heterologously expressed members of GH5-23-McGlc from Mucor circinelloides and PcGlc from Penicillium chrysogenum. Both enzymes exhibited the highest hydrolytic activities with quercetin-3-β-O-glucopyranoside, whereas lower specificity constants were determined with the rutinosides narcissin, rutin and hesperidin. High stabilities against thermal, ethanol and dimethyl sulfoxide-induced inactivation, a very limited secondary hydrolysis of the formed transglycosylation products, and no detectable product inhibition were additional features appropriate for biotechnological applications. The enzymes were compared in their efficiencies to hydrolyze rutin and to synthesize 2-phenylethyl rutinoside under homogeneous and heterogeneous reaction conditions using high rutin concentrations of 100 and 300 mM. Highest transglycosylation efficiencies were achieved with fully dissolved rutin in reaction mixtures containing 25% dimethyl sulfoxide. Molecular docking and multiple sequence alignments suggest that the hydrophobic environment of aromatic residues within the + 1 subsite of GH5-23 glycosidases is very important for the binding of flavonoid glucosides and rutinosides.

• Publikační typ
• časopisecké články MeSH