24 research outputs found
Students Learning Research Process in Fashion Design in the Context of Sustainability: Development of New Products from Non-traditional Materials
The article analyzes one of the most pressing problems of waste-utilization. In other words looking at nearby objects, taking into account the long-term evolution of the planet. Introducing the processing facilities, promotion of unexpected and interesting design solutions, providing unnecessary items on a „second breath”. It is shown that environmental friendliness is not boring or very difficult, but interesting and promising. An introduction to students, setting up a facility to learn how to apply the principles of composition, artistic expression and harmonization measures, and learn about the design and manufacturing technology, new materials, original techniques and learn to creatively apply knowledge and professional practice. In particular, attention is drawn to high-quality and thorough completion of tasks. The aim of the study: sustainability awareness and development of the research competence of prospective designers, exploring the usage of non-traditional material within professional fashion design and design studies in the context of sustainability. The methods of research- theoretical -analysis of the literature, empirical – qualitative research methods such as the analysis of the study tasks implemented by the Rezeknes Augstskola and Utenos Collegia study programs “Clothes design and technology”, observation and analysis of students’ creative activity
Investigation of antibacterial and antiinflammatory activities of proanthocyanidins from pelargonium sidoides dc root extract
The study explores antibacterial, antiinflammatory and cytoprotective capacity of Pelargonium sidoides DC root extract (PSRE) and proanthocyanidin fraction from PSRE (PACN) under conditions characteristic for periodontal disease. Following previous finding that PACN exerts stronger suppression of Porphyromonas gingivalis compared to the effect on commensal Streptococcus salivarius, the current work continues antibacterial investigation on Staphylococcus aureus, Staphylococcus epidermidis, Aggregatibacter actinomycetemcomitans and Escherichia coli. PSRE and PACN are also studied for their ability to prevent gingival fibroblast cell death in the presence of bacteria or bacterial lipopolysaccharide (LPS), to block LPS-or LPS + IFNγ-induced release of inflammatory mediators, gene expression and surface antigen presentation. Both PSRE and PACN were more efficient in suppressing Staphylococcus and Aggregatibacter compared to Escherichia, prevented A. actinomycetemcomitans-and LPS-induced death of fibroblasts, decreased LPS-induced release of interleukin-8 and prostaglandin E2 from fibroblasts and IL-6 from leukocytes, blocked expression of IL-1β, iNOS, and surface presentation of CD80 and CD86 in LPS + IFNγ-treated macrophages, and IL-1β and COX-2 expression in LPS-treated leukocytes. None of the investigated substances affected either the level of secretion or expression of TNFα. In conclusion, PSRE, and especially PACN, possess strong antibacterial, antiinflammatory and gingival tissue protecting properties under periodontitis-mimicking conditions and are suggestable candidates for treatment of the disease
Antioxidant and Mitochondria-Targeted Activity of Caffeoylquinic-Acid-Rich Fractions of Wormwood (Artemisia absinthium L.) and Silver Wormwood (Artemisia ludoviciana Nutt.)
Caffeoylquinic acids are some of the chemophenetically significant specialized metabolites
found in plants of the family Asteraceae Dumort., possessing a broad spectrum of biological activities.
As they might be potential mitochondria-targeted antioxidants, effective preparation methods -
including extraction, isolation, and purification of caffeoylquinic acids from plant sources - are in
great demand. The aim of this study was to fractionate the caffeoylquinic acids from cultivated
wormwood (Artemisia absinthium L.) and silver wormwood (Artemisia ludoviciana Nutt.) herb acetone
extracts and evaluate their phytochemical profiles, antioxidant activity (radical scavenging and re-
ducing activities), effects on kidney mitochondrial functions, and cytochrome-c-reducing properties.
The main findings of our study are as follows: (1) Aqueous fractions purified from wormwood
and silver wormwood herb acetone extracts are rich in monocaffeoylquinic acids (chlorogenic acid,
neochlorogenic acid, 4-O-caffeoylquinic acid), while methanolic fractions purified from wormwood
and silver wormwood herb acetone extracts are rich in dicaffeoylquinic acids (4,5-dicaffeoylquinic
acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid). Aqueous fractions purified from worm-
wood and silver wormwood herb acetone extracts were solely composed of monocaffeoylquinic acids.
Methanolic fractions purified from wormwood and silver wormwood herb acetone extracts con-
tained only dicaffeoylquinic acids. (2) Fractions purified from silver wormwood herb acetone extracts
stood out as having the greatest content of caffeoylquinic acids. (3) The greatest radical scavenging
activity was determined in the dicaffeoylquinic-acid-rich fraction purified from silver wormwood
herb acetone extract; the greatest reducing activity was determined in the dicaffeoylquinic-acid-
rich fraction purified from wormwood herb acetone extract. (4) The effect of both fractions on
mitochondrial functions was dose-dependent; lower concentrations of caffeoylquinic-acid-rich frac-
tions had no effect on mitochondrial functions, whereas higher concentrations of caffeoylquinic-
acid-rich fractions reduced the state 3 respiration rate (with the complex-I-dependent substrate
glutamate/malate). (5) Both monocaffeoylquinic- and dicaffeoylquinic-acid-rich fractions possessed
cytochrome-c-reducing properties; the greatest cytochrome c reduction properties were determined
in the dicaffeoylquinic-acid-rich fraction purified from wormwood herb acetone extract. In sum-
mary, these findings show that caffeoylquinic acids might be beneficial as promising antioxidant
and cytochrome-c-reducing agents for the modulation of mitochondria and treatment of various
mitochondrial-pathway-associated pathologies
Energetics of Glucose Metabolism: A Phenomenological Approach to Metabolic Network Modeling
A new formalism to describe metabolic fluxes as well as membrane transport processes was developed. The new flux equations are comparable to other phenomenological laws. Michaelis-Menten like expressions, as well as flux equations of nonequilibrium thermodynamics, can be regarded as special cases of these new equations. For metabolic network modeling, variable conductances and driving forces are required to enable pathway control and to allow a rapid response to perturbations. When applied to oxidative phosphorylation, results of simulations show that whole oxidative phosphorylation cannot be described as a two-flux-system according to nonequilibrium thermodynamics, although all coupled reactions per se fulfill the equations of this theory. Simulations show that activation of ATP-coupled load reactions plus glucose oxidation is brought about by an increase of only two different conductances: a [Ca2+] dependent increase of cytosolic load conductances, and an increase of phosphofructokinase conductance by [AMP], which in turn becomes increased through [ADP] generation by those load reactions. In ventricular myocytes, this feedback mechanism is sufficient to increase cellular power output and O2 consumption several fold, without any appreciable impairment of energetic parameters. Glucose oxidation proceeds near maximal power output, since transformed input and output conductances are nearly equal, yielding an efficiency of about 0.5. This conductance matching is fulfilled also by glucose oxidation of β-cells. But, as a price for the metabolic mechanism of glucose recognition, β-cells have only a limited capability to increase their power output
Application of the Principles of Systems Biology and Wiener’s Cybernetics for Analysis of Regulation of Energy Fluxes in Muscle Cells in Vivo
The mechanisms of regulation of respiration and energy fluxes in the cells are analyzed based on the concepts of systems biology, non-equilibrium steady state kinetics and applications of Wiener’s cybernetic principles of feedback regulation. Under physiological conditions cardiac function is governed by the Frank-Starling law and the main metabolic characteristic of cardiac muscle cells is metabolic homeostasis, when both workload and respiration rate can be changed manifold at constant intracellular level of phosphocreatine and ATP in the cells. This is not observed in skeletal muscles. Controversies in theoretical explanations of these observations are analyzed. Experimental studies of permeabilized fibers from human skeletal muscle vastus lateralis and adult rat cardiomyocytes showed that the respiration rate is always an apparent hyperbolic but not a sigmoid function of ADP concentration. It is our conclusion that realistic explanations of regulation of energy fluxes in muscle cells require systemic approaches including application of the feedback theory of Wiener’s cybernetics in combination with detailed experimental research. Such an analysis reveals the importance of limited permeability of mitochondrial outer membrane for ADP due to interactions of mitochondria with cytoskeleton resulting in quasi-linear dependence of respiration rate on amplitude of cyclic changes in cytoplasmic ADP concentrations. The system of compartmentalized creatine kinase (CK) isoenzymes functionally coupled to ANT and ATPases, and mitochondrial-cytoskeletal interactions separate energy fluxes (mass and energy transfer) from signalling (information transfer) within dissipative metabolic structures – intracellular energetic units (ICEU). Due to the non-equilibrium state of CK reactions, intracellular ATP utilization and mitochondrial ATP regeneration are interconnected by the PCr flux from mitochondria. The feedback regulation of respiration occurring via cyclic fluctuations of cytosolic ADP, Pi and Cr/PCr ensures metabolic stability necessary for normal function of cardiac cells
Analysis of effects of 2,2',5,5'-tetracholorobiphenyl on the flux control in oxidative phosphorylation system in rat liver mitochondria.
Modular kinetic analysis reveals that the environmental pollutant 2,2′,5,5′tetrachlorobiphenyl (2,2′,5,5′-TCB) affects a large number of steps in oxidative phosphorylation in rat liver mitochondria. 2,2′,5,5′-TCB increases membrane permeability to ions, and inhibits NADH dehydrogenase, cytochrome bcl, cytochrome oxidase (all in the respiratory chain) and ATP-synthase (in the phosphorylation subsystem). Surprisingly, flux control distribution does not change. A kinetic model for oxidative phosphorylation was used to simulate these findings, and it was found that combined large changes in the processes indicated indeed left the flux control largely unchanged. In addition, computational analysis with the model indicated that the adenine nucleotide translocator might be inhibited by 2,2′,5,5′-TCB
Caffeic Acid Phenethyl Ester Reduces Ischemia-Induced Kidney Mitochondrial Injury in Rats
During partial nephrectomy, the avoidance of ischemic renal damage is extremely important as duration of renal artery clamping (i.e., ischemia) influences postoperative kidney function. Mitochondria (main producer of ATP in the cell) are very sensitive to ischemia and undergo damage during oxidative stress. Finding of a compound which diminishes ischemic injury to kidney is of great importance. Caffeic acid phenethyl ester (CAPE), biologically active compound of propolis, might be one of the promising therapeutic agents against ischemia-caused damage. Despite wide range of biological activities of CAPE, detailed biochemical mechanisms of its action at the level of mitochondria during ischemia are poorly described and need to be investigated. We investigated if CAPE (22 mg/kg and 34 mg/kg, injected intraperitoneally) has protective effects against short (20 min) and longer time (40 min) rat kidney ischemia in an in vitro ischemia model. CAPE ameliorates in part ischemia-induced renal mitochondrial injury, improves oxidative phosphorylation with complex I-dependent substrate glutamate/malate, increases Ca2+ uptake by mitochondria, blocks ischemia-induced caspase-3 activation, and protects kidney cells from ischemia-induced necrosis. The protective effects on mitochondrial respiration rates were seen after shorter (20 min) time of ischemia whereas reduction of apotosis and necrosis and increase in Ca2+ uptake were revealed after both, shorter and longer time of ischemia
Modular kinetic analysis reveals differences in Cd2+ and Cu2+ ion-induced impairment of oxidative phosphorylation in liver.
Impaired mitochondrial function contributes to copper- and cadmium-induced cellular dysfunction. In this study, we used modular kinetic analysis and metabolic control analysis to assess how C