457 resultados para NAD
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Objective- This study investigated whether differences exist in atherogen-induced migratory behaviors and basal antioxidant enzyme capacity of vascular smooth muscle cells (VSMC) from human coronary (CA) and internal mammary (IMA) arteries. Methods- Migration experiments were performed using the Dunn chemotaxis chamber. The prooxidant [NAD(P)H oxidase] and antioxidant [NOS, superoxide dismutase, catalase and glutathione peroxidase] enzyme activities were determined by specific assays. Results- Chemotaxis experiments revealed that while both sets of VSMC migrated towards platelet-derived growth factor-BB (1-50 ng/ml) and angiotensin II (1-50 nM), neither oxidized-LDL (ox-LDL, 25-100 g/ml) nor native LDL (100 g/ml) affected chemotaxis in IMA VSMC. However, high dose ox-LDL produced significant chemotaxis in CA VSMC that was inhibited by pravastatin (100 nM), mevastatin (10 nM), losartan (10 nM), enalapril (1 M), and MnTBAP (a free radical scavenger, 50M). Microinjection experiments with isoprenoids i.e. geranylgeranylpyrophosphate (GGPP) and farnesylpyrophosphate (FPP) showed distinct involvement of small GTPases in atherogen-induced VSMC migration. Significant increases in antioxidant enzyme activities and nitrite production along with marked decreases in NAD(P)H oxidase activity and O2 .- levels were determined in IMA versus CA VSMC. Conclusions- Enhanced intrinsic antioxidant capacity may confer on IMA VSMC resistance to migration against atherogenic agents. Drugs that regulate ox-LDL or angiotensin II levels also exert antimigratory effects.
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Objective: Excess levels of free radicals such as nitric oxide (NO) and superoxide anion (O2-)are associated with the pathogenesis of endothelial cell dysfunction in diabetes mellitus. This study was designed to investigate the underlying causes of oxidative stress in coronary microvascular endothelial cells (CMEC) exposed to hyperglycaemia. Methods: CMEC were cultured under normal (5.5 mmol/L) or high glucose (22 mmol/L)concentrations for 7 days. The activity and expression (protein level) of eNOS, iNOS, NAD(P)H oxidase and antioxidant enzymes, namely, superoxide dismutase (SOD), catalase and glutahione peroxidase (GPx) were investigated by specific activity assays and Western analyses,respectively while the effects of hyperglycaemia on nitrite and O2 - generation were investigated by Griess reaction and cytochrome C reduction assay, respectively. Results: Hyperglycaemia did not alter eNOS or iNOS protein expressions and overall nitrite generation, an index of NO production. However, it significantly reduced the levels of intracellular antioxidant glutathione by 50% (p<0.05) and increased the protein expressions and/or activities of p22-phox, a membrane-bound component of pro-oxidant NAD(P)H oxidase and antioxidant enzymes (p<0.05). Free radical-scavengers, namely, Tiron and MPG (0.1-1 mol/L) reduced hyperglycaemia-induced antioxidant enzyme activity and increased glutathione and nitrite generation to the levels observed in CMEC cultured in normoglycaemic medium (p<0.01). The differences in enzyme activity and expressions were independent of the increased osmolarity generated by high glucose levels as investigated by using equimolar concentrations of mannitol in parallel experiments. Conclusions: These results suggest that hyperglycaemia-induced oxidative stress may arise in CMEC as a result of enhanced prooxidant enzyme activity and diminished generation of 3 antioxidant glutathione. By increasing the antioxidant enzyme capacity CMEC may protect themselves against free radical-induced cell damage in diabetic conditions. The definitive version is available at http://www.blackwell-synergy.com
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Wydzia Studiw Edukacyjnych: Zakad Edukacji Wielokulturowej i Bada Nad Nierwnociami Spoecznymi
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Wydzia Nauk Spoecznych: Instytut Kulturoznawstwa
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The article reflects on a pilot teacher training programme in Tanzania, where videos are used for implementing new teaching methods, but also for initiating a discourse about corporal punishment. The culture of instruction in Tanzania is strictly based on a teacher-centred approach which leaves all activity to the teacher and turns students into passive listeners. In most cases, teachers deal with up to 80 students in one classroom. Therefore, discipline is an important matter of instruction and many teachers still use corporal punishment that is widely accepted in Tanzania. The launched training programme has the aim of implementing learner-centred teaching methods without using corporal punishment and offers Tanzanian teachers the possibility to participate in a workshop that connects these methods with subject-related topics. In the English teaching workshop, the facilitator used filmed English lessons from a German school to discuss with the participants both the application of learner-centred methods and the absence of corporal punishment. The use of these German videos shows advantages but also limitations that are strongly related to the European versus African setting. The article discusses these dimensions on the basis of data that are generated by ethnographical observation and audiotranscripts of the piloted workshop.
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Celem niniejszego tekstu jest pokazanie, w jaki sposb Batesonowskie pojcie metakomunikacji jest uytecznym punktem wyjcia do analiz prowadzonych nad sposobem uprawiania komunikologii historycznej . Podejmujc si analiz z zakresu historii idei komunikacji oraz filozofii komunikacji, natrafiamy na istotny problem badawczy: w jaki sposb mona analizowa przesze sposoby mylenia i komunikowania o komunikacji, jeli komunikacja jest nieustannym procesem odnoszcym si do samego siebie. Okazuje si, e metodologiczne wyzwanie stojce przed badaczami, ktrzy pisz histori komunikacji w ramach dyscypliny okrelanej mianem komunikologii historycznej, moe by wsparte rozwaaniami Gregorego Batesona na temat procesu metakomunikacji. Dlatego w dalszej czci niniejszego tekstu pokazuj, w jaki sposb, korzystajc z ustale Batesona, rozwijam pojcie metakomunikacji i aplikuj na gruncie komunikologii historycznej. Myl Batesona jest niezwykle uyteczna do rozwaa metodologicznych i moe stanowi punkt wyjcia do budowania nowych narzdzi filozoficznych sucych analizowaniu zmian spoecznych.
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Celem artykuu jest prezentacja myli politycznej Ruchu Spoeczestwa Alternatywnego. W artytkule prezentowana jest diagnoza stanu sytuacji spoeczenej w Polsce pierwszej poowy lat 80 prezentowana na amach "Homka", propozycje programowe RSA oraz dyskuja nad metodami i strategi dziaania politycznego.
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Apesar de ser um micronutriente essencial aos organismos, o cobre (Cu) txico quando presente em elevadas concentraes na gua. O mecanismo pelo qual este metal exerce sua toxicidade em invertebrados marinhos ainda no est bem estabelecido. Dentre os diversos efeitos relatados, observa-se uma reduo do consumo de oxignio corporal e tecidual no marisco Mesodesma mactroides exposto (96 h) ao Cu (150 g L-1 ) em gua do mar (salinidade 30). Portanto, o objetivo do presente estudo foi avaliar os efeitos desta exposio ao Cu no metabolismo energtico em teciduais do marisco M. mactroides. Os contedos de ATP e coenzimas (NAD+ e NADH) nas brnquias, glndula digestiva e msculo pedal no foram alterados pela exposio ao Cu, indicando que estes tecidos mantiveram suas capacidades de produo aerbica de energia. Porm, foi observada uma reduo no contedo hemolinftico de ATP. Quanto ao contedo de protenas, houve um aumento na glndula digestiva, que pode estar associado maior oxidao de protenas j relatada para esse tecido aps exposio ao Cu. Os contedos de lipdios, glicognio e glicose permaneceram inalterados em todos os tecidos analisados, exceto no msculo pedal, onde foi observada uma reduo no contedo de glicose. Por isso, os contedos de piruvato e lactato tambm foram analisados no msculo pedal e na hemolinfa. Em ambos tecidos, foi observado um aumento do contedo de lactato, sem alterao no contedo de piruvato. Portanto, os resultados do presente estudo sugerem que os tecidos de M. mactroides utilizam a anaerobiose para obteno de energia durante a exposio ao Cu, conforme demonstrado no msculo pedal e hemolinfa. Apesar disso, a hemolinfa no capaz de manter o nvel de ATP nas condies experimentais testadas.
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Wydzia Nauk Politycznych i Dziennikarstwa
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Instytucja mw zaufania, czsto okrelana mianem niemych obserwatorw wyborw, traktowana jest z duym dystansem i budzi wrd przedstawicieli doktryny prawa konstytucyjnego, jak rwnie wiata polityki, wiele wtpliwoci. Zadaniem mw zaufania jest reprezentowanie podczas wyborw interesu kandydata, bd listy kandydatw, przed komisj wyborcz i czuwanie nad prawidowym przebiegiem czynnoci wyborczych, w tym przede wszystkim zliczaniem gosw i ustalaniem wynikw wyborw. Ma zatem istotne znaczenie dla zapewnienia rzetelnoci i uczciwoci procedur wyborczych, jak rwnie poszanowania podstawowych zasad prawa wyborczego, w szczeglnoci zasady powszechnoci i wolnoci wyborw oraz tajnoci gosowania. Niestety w Kodeksie wyborczym uregulowana jest stosunkowo fragmentarycznie, za jej dookrelenie znajduje si w wytycznych Pastwowej Komisji Wyborczej. Przed wyborami pojawiaj si rwnie rne (opracowywane najczciej przez partie polityczne) instrukcje, okrelane take mianem vademecum, czy poradniki dla mw zaufania, ktrych tre moe budzi wtpliwoci. Wywouje to potrzeb debaty przedstawicieli doktryny i politykw nad funkcjami i konstrukcj prawn instytucji mw zaufania w polskim prawie wyborczym, jak i stosownymi jego zmianami.
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Wydzia Nauk Spoecznych: Instytut Socjologii
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Wydzia Historyczny
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Wydzia Neofilologii
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Wydzia Nauk Politycznych i Dziennikarstwa
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Aims: Hyperglycaemia (HG), in stroke patients, is associated with worse neurological outcome by compromising endothelial cell function and the bloodbrain barrier (BBB) integrity. We have studied the contribution of HG-mediated generation of oxidative stress to these pathologies and examined whether antioxidants as well as normalization of glucose levels following hyperglycaemic insult reverse these phenomena. Methods: Human brain microvascular endothelial cell (HBMEC) and human astrocyte co-cultures were used to simulate the human BBB. The integrity of the BBB was measured by transendothelial electrical resistance using STX electrodes and an EVOM resistance meter, while enzyme activities were measured by specific spectrophotometric assays. Results: After 5 days of hyperglycaemic insult, there was a significant increase in BBB permeability that was reversed by glucose normalization. Co-treatment of cells with HG and a number of antioxidants including vitamin C, free radical scavengers and antioxidant enzymes including catalase and superoxide dismutase mimetics attenuated the detrimental effects of HG. Inhibition of p38 mitogen-activated protein kinase (p38MAPK) and protein kinase C but not phosphoinositide 3 kinase (PI3 kinase) also reversed HG-induced BBB hyperpermeability. In HBMEC, HG enhanced pro-oxidant (NAD(P)H oxidase) enzyme activity and expression that were normalized by reverting to normoglycaemia. Conclusions: HG impairs brain microvascular endothelial function through involvements of oxidative stress and several signal transduction pathways.
