Deoxygenation of fatty acids for production of fuels and chemicals

The decreasing fossil fuel resources combined with an increasing world energy demand has raised an interest in renewable energy sources. The alternatives can be solar, wind and geothermal energies, but only biomass can be a substitute for the carbon���based feedstock, which is suitable for the production of transportation fuels and chemicals. However, a high oxygen content of the biomass creates challenges for the future chemical industry, forcing the development of new processes which allow a complete or selective oxygen removal without any significant carbon loss. Therefore, understanding and optimization of biomass deoxygenation processes are crucial for the future bio���based chemical industry. In this work, deoxygenation of fatty acids and their derivatives was studied over Pd/C and TiO2 supported noble metal catalysts (Pt, Pt���Re, Re and Ru) to obtain future fuel components. The 5 % Pd/C catalyst was investigated in semibatch and fixed bed reactors at 300 ��C and 1.7���2 MPa of inert and hydrogen���containing atmospheres. Based on extensive kinetic studies, plausible reaction mechanisms and pathways were proposed. The influence of the unsaturation in the deoxygenation of model compounds and industrial feedstock ��� tall oil fatty acids ��� over a Pd/C catalyst was demonstrated. The optimization of the reaction conditions suppressed the formation of by���products, hence high yields and selectivities towards linear hydrocarbons and catalyst stability were achieved. Experiments in a fixed bed reactor filled with a 2 % Pd/C catalyst were performed with stearic acid as a model compound at different hydrogen���containing gas atmospheres to understand the catalyst stability under various conditions. Moreover, prolonged experiments were carried out with concentrated model compounds to reveal the catalyst deactivation. New materials were proposed for the selective deoxygenation process at lower temperatures (~200 ��C) with a tunable selectivity to hydrodeoxygenation by using 4 % Pt/TiO2 or decarboxylation/decarbonylation over 4 % Ru/TiO2 catalysts. A new method for selective hydrogenation of fatty acids to fatty alcohols was demonstrated with a 4 % Re/TiO2 catalyst. A reaction pathway and mechanism for TiO2 supported metal catalysts was proposed and an optimization of the process conditions led to an increase in the formation of the desired products.

Effect of FSH and insulin on lipogenesis in cultures of Sertoli cells from immature rats

Follicle-stimulating hormone (FSH) and insulin regulate glycide metabolism in Sertoli cells, thus stimulating lactate production. These stimulatory effects of FSH and insulin do not require protein synthesis, suggesting a modulation of enzyme activity and/or regulation of glucose transport. The present investigation was performed to characterize the hormonal control of lipid metabolism in Sertoli cells. The data indicate that FSH and insulin have a regulatory effect on lipid metabolism in Sertoli cells. After 8 h of preincubation with insulin (5 ��g/ml), the activity of the enzyme ATP-citrate lyase in cultured Sertoli cells was increased from 0.19 to 0.34 nmol NAD+ formed ��g protein-1 min-1. FSH (100 ng/ml) had no effect on this enzyme. Glycerol phosphate dehydrogenase activity was not affected by any of the hormones tested. When Sertoli cells from 19-day old rats were incubated with [1,2��14C]acetate for 90 or 360 min, the [14C] label was present predominantly in triglyceride and phospholipid fractions with minor amounts in other lipids. In Sertoli cells pretreated for 16 h with insulin and FSH, an increase in acetate incorporation into lipids was observed. Most of the label was in esterified lipids and this percentage increased with the time of treatment; this increase was remarkable in triglycerides of control cells (18.8% to 30.6%). Since Sertoli cell triglycerides participate in the control of spermatogenesis, the present data suggest that the hormonal control of lipid metabolism in Sertoli cells is important not only for maintaining the energy of the cell itself, but also for the control of the spermatogenesis process.

Recent advances in angiotensin II signaling

Angiotensin II (Ang II)* is a multifunctional hormone that influences the function of cardiovascular cells through a complex series of intracellular signaling events initiated by the interaction of Ang II with AT1 and AT2 receptors. AT1 receptor activation leads to cell growth, vascular contraction, inflammatory responses and salt and water retention, whereas AT2 receptors induce apoptosis, vasodilation and natriuresis. These effects are mediated via complex, interacting signaling pathways involving stimulation of PLC and Ca2+ mobilization; activation of PLD, PLA2, PKC, MAP kinases and NAD(P)H oxidase, and stimulation of gene transcription. In addition, Ang II activates many intracellular tyrosine kinases that play a role in growth signaling and inflammation, such as Src, Pyk2, p130Cas, FAK and JAK/STAT. These events may be direct or indirect via transactivation of tyrosine kinase receptors, including PDGFR, EGFR and IGFR. Ang II induces a multitude of actions in various tissues, and the signaling events following occupancy and activation of Ang receptors are tightly controlled and extremely complex. Alterations of these highly regulated signaling pathways may be pivotal in structural and functional abnormalities that underlie pathological processes in cardiovascular diseases such as cardiac hypertrophy, hypertension and atherosclerosis.

Respiration, oxidative phosphorylation, and uncoupling protein in Candida albicans

The respiration, membrane potential (<FONT FACE=Symbol>Dy</FONT>), and oxidative phosphorylation of mitochondria in situ were determined in spheroplasts obtained from Candida albicans control strain ATCC 90028 by lyticase treatment. Mitochondria in situ were able to phosphorylate externally added ADP (200 ��M) in the presence of 0.05% BSA. Mitochondria in situ generated and sustained stable mitochondrial <FONT FACE=Symbol>Dy</FONT> respiring on 5 mM NAD-linked substrates, 5 mM succinate, or 100 ��M N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride plus 1 mM ascorbate. Rotenone (4 ��M) inhibited respiration by 30% and 2 ��M antimycin A or myxothiazole and 1 mM cyanide inhibited it by 85%. Cyanide-insensitive respiration was partially blocked by 2 mM benzohydroxamic acid, suggesting the presence of an alternative oxidase. Candida albicans mitochondria in situ presented a carboxyatractyloside-insensitive increase of <FONT FACE=Symbol>Dy</FONT> induced by 5 mM ATP and 0.5% BSA, and <FONT FACE=Symbol>Dy</FONT> decrease induced by 10 ��M linoleic acid, both suggesting the existence of an uncoupling protein. The presence of this protein was subsequently confirmed by immunodetection and respiration experiments with isolated mitochondria. In conclusion, Candida albicans ATCC 90028 possesses an alternative electron transfer chain and alternative oxidase, both absent in animal cells. These pathways can be exceptional targets for the design of new chemotherapeutic agents. Blockage of these respiratory pathways together with inhibition of the uncoupling protein (another potential target for drug design) could lead to increased production of reactive oxygen species, dysfunction of Candida mitochondria, and possibly to oxidative cell death.

Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5��2.1 vs 23��2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP&#8722;LNaMAP) was 6.0��1.9 vs 12.7��1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi&#8805;10 mmHg), whereas in the AD group &#8764;50% showed cSSHT. A 45% reduction in pNOB (P&#8804;0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.

Le discours de crise: La repr��sentation des r��fugi��s dans le Figaro et Lib��ration

Under september ma��nad 2015 gav so��kordet ���kris��� dagligen upphov till ett trettiotal tra��ffar i so��kmotorn till Frankrikes sto��rsta dagstidningar. Dagspressen o��verflo��das av kriser och i skrivande stund a��r den mest omtalade krisen de flyktingstro��mmar som na��r Europa som resultat efter flera a��rs krig i Mellano��stern. Pro gradu-avhandlingen studerar flyktingkrisen som en diskursiv ha��ndelse, en social konstruktion av en fo��reteelse som tar de aktuella personerna och deras a��sikter i beaktande. Avhandlingen a��r uppbyggd som en linje som inleds med mediestrategier och ga��r till iscensa��ttandet av nyheten, fo��r att sedan analysera de olika a��sikterna och personerna som ger upphov till lingvistisk polyfoni och ma��ngtydighet. Syftet med avhandlingen a��r att studera hur medierna pa��verkar va��r fo��rsta��else av en kris. Fo��r att fa�� en dynamisk bild av bevakningen av flyktingkrisen studeras rubriker till ett hundratal titlar som publicerats i september 2015 av tva�� stora franska dagstidningar: Le Figaro och Libe��ration. Tidningarnas motsatta politiska orientering sta��r som grund fo��r en helta��ckande och varierande genomla��sning av medieuppma��rksamheten kring flyktingkrisen. Som metod utfo��rs en diskursanalys pa�� materialet fo��r att fa�� reda pa�� hur de ba��da tidningarna framsta��ller krisen. Skillnader och likheter studeras, sa��va��l som fo��rekommande teman och en karakteristisk vokabula��r i anknytning till krisen. Hypotesen a��r att flyktingarnas egna a��sikter kommer i skymundan i medierna. Som resultat har jag noterat element i krisen som tidigare framsta��llts som viktiga ur lingvistisk synvinkel pa�� krisdiskurs av lingvisten Marie Veniard. Uto��ver det observeras na��gra kompletterande betydelsekomponenter som sta��r i fo��rbindelse med flyktingkrisens komplexa natur. Ett speciellt mo��nster fo��r att framsta��lla flyktingarna har visat sig vara ofta fo��rekommande i de ba��da tidningarna. Flyktingarna na��mns fo��r att ge rubrikerna ett autentiskt va��rde men paradoxalt nog mo��jliggo��r de a��ven otydlighet i fra��ga om vem som faktiskt yttrar sig, flyktingarna eller journalisterna?

Expression and function of endothelin and its receptors in vascular adventitial fibroblasts

Objective: The adventitia has been recognized to play important roles in vascular oxidative stress, remodelling and contraction. We recently demonstrated that adventitial fibroblasts are able to express endothelin-1 (ET-1) in response to angiotensin II (ANG II). However, the mechanisms by which ANG II induces ET-1 expression are unknown. It is also unclear whether the ET-1 receptors are expressed in the adventitia. We therefore examined the role of oxidative stress in the regulation of ET-1. We also investigated the expression of both the ETA and ETB receptors and the roles of these two types of receptors in collagen synthesis and ET-1 clearance in adventitial fibroblasts. Methods and Results: Adventitial fibroblasts were isolated and cultured from the thoracic mouse aorta. Cells were treated with ANG II (lOOnM), ET-1 (lOpM), NADPH oxidase inhibitor apocynin (lOOfiM), the superoxide anion scavenger tempol (lOOfiM), the ANG II receptor antagonists (100[aM), losartan (AT| receptor) and PD 1233 19 (AT2 receptor), the ET-1 receptor antagonists (lOOuM), BQ123 (ETA receptor) and BQ788 (ETB receptor), and the ETB receptor agonist (lOOnM) Sarafotoxin 6C. ET-1 peptide levels were determined by ELISA, while ETA ,ETB and collagen levels were determined by Western blot. ANG II increased ET-1 peptide levels in a time-dependent manner reaching significance when incubated for 24 hours. NAD(P)H oxidase inhibitor, apocynin, as well as the superoxide scanverger, tempol, significantly reduced ANG Il-induced ET-1 peptide levels while over-expression of SOD1 (endogenous antioxidant enzyme) significantly decreased ANG Il-induced collagen I expression, therefore implicating reactive oxygen species in the mediation of ET-1. ANG II increased ETA receptor protein as well as collagen in a similar fashion, reaching significance after 4, 6, and 24 hours treatment. ANG II induced collagen was reduced while in the presence of the ETA receptor antagonist suggesting the role of the ETa receptor in the regulation of the extracellular matrix. ANG II treatment also increased ETB receptor protein levels in a time-dependent manner. ANG II treatment in the presence of the ETB receptor antagonist significantly increased ET-1 peptide levels. On another hand, the ETB receptor agonist, Sarafotoxin 6C, significantly decreased ET-1 peptide levels. These data implicate the role of the ETb receptor in the clearance of the ET-1 peptide. Conclusion: ANG II-induced increases of ET-1 peptide appears to be mediated by reactive oxygen species derived from NAD(P)H oxidase. Both the ETA and ETB receptors are expressed in adventitial fibroblasts. The ETA receptor subtype mediates collagen I expression, while the ETB receptor may play a protective role through increasing the clearance of the ET- 1 peptide.

Mechanisms of endothelin-1 induced reactive oxygen species production in vascular adventitial fibroblasts

With the relationship between endothelin-1 (ET-1) stimulation and reactive oxygen species (ROS) production unknown in adventitial fibroblasts, I examined the ROS response to ET-1 and angiotensin (Ang II). ET-1 -induced ROS peaked following 4 hrs of ET-1 stimulation and was inhibited by an ETA receptor antagonist (BQ 123, 1 uM) an extracellular signal-regulated kinase (ERK) 1/2 inhibitor (PD98059, 10 uM), and by both a specific, apocynin (10 uM), and non-specific, diphenyleneiodonium (10 uM), NAD(P)H oxidase inhibitor. NOX2 knockout fibroblasts did not produce an ET-1 induced change in ROS levels. Ang II treatment increased ROS levels in a biphasic manner, with the second peak occurring 6 hrs following stimulation. The secondary phase of Ang II induced ROS was inhibited by an ATi receptor antagonist, Losartan (100 uM) and BQ 123. In conclusion, ET-1 induces ROS production primarily through an ETA-ERKl/2 NOX2 pathway, additionally, Ang II-induced ROS production also involves an ETa pathway.

The roles of ERK1/2 and PI3K in abnormal vascular functions in angiotensin II-infused hypertensive rats

Background: Ang II plays a major role in cardiovascular regulation. Recently, it has become apparent that vascular superoxide anion may play an important role in hypertension development. Treatment with antisense NAD(P)H oxidase or SOD decreased BP in Ang II-infused rats. Wang et al recently reported mice which lack one of the subunits of NAD(P)H oxidase developed hypertension at a much lower extent when compared to the wild type animals infused with Ang II, indicating that superoxide anion contributes to elevation in BP in the Ang II-infused hypertensive model. In the Ang II-infused hypertensive model, altered reactivity of blood vessels is often associated with the elevation of systolic blood pressure. We have observed abnormal tension development and impaired endothelium-dependent relaxation in the isolated aorta of Ang II-infused and DOCA-salt hypertensive rats. Recently, several other cellular signal molecules, including ERK1I2 and PI3K, have been determined to play important roles in the regulation of smooth muscle contraction and relaxation. ERKl/2 and PI3K pathways are also reported to contribute to Ang II induced cell growth, hypertrophy, remodeling and contraction. Moreover, these signaling pathways have shown ROS-sensitive properties. Therefore, the aim of the present study is to investigate the roles of ERKl12 and PI3K in vascular oxidative stress, spontaneous tone and impaired endothelium relaxation in Ang II-infused hypertensive model. Hypothesis: We hypothesize that the activation of ERKl12 and PI3K are elevated in response to an Ang II infusion for 6 days. The elevated activation of phospho-ERKl/2 and PI3K mediated the increased level of vascular superoxide anion, the abnormal vascular contraction and impaired endothelium-dependent vascular relaxation in Ang II-infused hypertensive rats. Methods: Vascular superoxide anion level is measured by lucigenin chemiluminescence. Spontaneous tone and ACh-induced endothelium-dependent relaxation was measured by isometric tension recording in organ chamber. The activity of ERK pathway will be measured by its Western blot of phosphorylation of ERK. PI3K activity was evaluated indirectly by Western blot of the phosphorylation of PDKl, a downstream protein of PI3K signaling pathway. The role of each pathway was also addressed via comparing the responses to the specific inhibitors. Results: Superoxide anion was markedly increased in the isolated thoracic aorta from Ang II-infused rats. There was spontaneous tone developed in rings from Ang II-induced hypertensive but not sham-operated normotensive rats. ACh-induced endothelium-dependent relaxation function is impaired in Ang II-infused hypertensive rats. Superoxide dismutase and NAD(P)H oxidase inhibitor, apocynin, inhibited the abnormal spontaneous tone and ameliorated impaired endothelium-dependent relaxation. The expression of phopho-ERKII2 was enhanced in Ang II-infused rats, indicating the activity of ERK1I2 could be increased. MEK1I2 inhibitors, PD98059 and U126, but not their inactive analogues, SB203580 and U124, significantly reduced the vascular superoxide anion in aortas from Ang II-infused rats. The MEK1I2 inhibitors reduced the spontaneous tone and improved the impaired endothelium-dependent relaxation in aorta of hypertension. These findings supported the role of ERKII2 signaling pathway in vascular oxidative stress, spontaneous tone and impaired endothelium-dependent relaxation in Ang II-infused hypertensive rats. The amount of phospho-PDK, a downstream protein of PI3K was increased in Ang II rats indicating the activity of PI3K activity was elevated. Strikingly, PI3K significantly inhibited the increase of superoxide anion level, abnormal spontaneous tone and restored endothelium-dependent relaxation in Ang II-infused hypertensive rats. These findings indicated the important role of PI3K in Ang II-infused hypertensive rats. Conclusion: ERKII2 and PI3K signaling pathways are sustained activated in Ang II-infused hypertensive rats. The activated ERKII2 and PI3K mediate the increase of vascular superoxide anion level, vascular abnormal spontaneous tone and impaired endothelium-dependent relaxation.

Hyperosmotic Stress and the Impact on Metabolite Formation and Redox Balance in Saccharomyces cerevisiae and Saccharomyces bayanus strains

Wine produced using an appassimento-type process represents a new and exciting innovation for the Ontario wine industry. This process involves drying grapes that have already been picked from the vine, which increases the sugar content due to dehydration and induces a variety of changes both within and on the surface of the grapes. Increasing sugar contents in musts subject wine yeast to conditions of high osmolarity during alcoholic fermentations. Under these conditions, yeast growth can be inhibited, target alcohol levels may not be attained and metabolic by-products of the hyperosmotic stress response, including glycerol and acetic acid, may impact wine composition. The further metabolism of acetic acid to acetylCoA by yeast facilitates the synthesis of ethyl acetate, a volatile compound that can also impact wine quality if present in sufficiently high concentrations. The first objective of this project was to understand the effect of yeast strain and sugar concentration on fermentation kinetics and metabolite formation, notably acetic acid and ethyl acetate, during fermentation in appassimento-type must. Our working hypotheses were that (1) the natural isolate Saccharomyces bayanus would produce less acetic acid and ethyl acetate compared to Saccharomyces cerevisiae strain EC-1118 fermenting the high and low sugar juices; (2) the wine produced using the appassimento process would contain higher levels of acetic acid and lower levels of ethyl acetate compared to table wine; (3) and the strains would be similar in the kinetic behavior of their fermentation performances in the high sugar must. This study determined that the S. bayanus strain produced significantly less acetic acid and ethyl acetate in the appassimento wine and table wine fermentations. Differences in acetic acid and ethyl acetate production were also observed within strains fermenting the two sugar conditions. Acetic acid production was higher in table wine fermented by S. bayanus as no acetic acid was produced in appassimento-style wine, and 1.4-times higher in appassimento wine fermented by EC-1118 over that found in table wine. Ethyl acetate production was 27.6-times higher in table wine fermented by S. bayanus, and 5.2-times higher by EC-1118, compared to that in appassimento wine. Sugar utilization and ethanol production were comparable between strains as no significant differences were determined. The second objective of this project was to bring a method in-house for measuring the concentration of pyridine nucleotides, NAD+, NADP+, NADH and NADPH, in yeast cytosolic extract. Development of this method is of applicative interest for our lab group as it will enable the redox balance of the NAD+/ NADH and NADP+/ NADPH systems to be assessed during high sugar fermentations to determine their respective roles as metabolic triggers for acetic acid production. Two methods were evaluated in this study including a UV-endpoint method using a set of enzymatic assay protocols outlined in Bergmeyer (1974) and a colorimetric enzyme cycling method developed by Sigma-Aldrich�� using commercial kits. The former was determined to be limited by its low sensitivity following application to yeast extract and subsequent coenzyme analyses, while the latter was shown to exhibit greater sensitivity. The results obtained from the kits indicated high linearity, accuracy and precision of the analytical method for measuring NADH and NADPH, and that it was sensitive enough to measure the low coenzyme concentrations present in yeast extract samples. NADtotal and NADPtotal concentrations were determined to be above the lower limit of quantification and within the range of the respective calibration curves, making this method suitable for our research purposes.

Le niveau r��duit d���AMPc dans la surexpression des prot��ines G(alpha)i et la prolif��ration accrue des cellules du muscle lisse vasculaire des rats spontan��ment hypertendus

Nous avons pr��c��demment montr�� que les cellules musculaires lisses vasculaires(CMLV) des rats spontan��ment hypertendus (SHR) pr��sentent une expression augment��e des prot��ines G inhibitrices (Gi) et une prolif��ration cellulaire accrue par rapport aux CMLV des rats Wystar-Kyoto (WKY). Le niveau d'AMPc s���est ��galement av��r�� plus faible dans les CMLV de SHR. La pr��sente ��tude a donc ��t�� entreprise afin d'examiner la contribution de la diminution du niveau intracellulaire d'AMPc �� l���augmentation de l'expression des prot��ines Gi et �� la prolif��ration accrue des CMLV de SHR et de continuer �� explorer les m��canismes mol��culaires sous-jacents responsables de cette r��ponse. Les CMLV de SHR ont montr�� par rapport aux CMLV des WKY une expression accrue de Gi��-2 et Gi��-3 qui a ��t�� diminu�� d'une mani��re d��pendante de concentration par le dbcAMP, un analogue d'AMPc perm��able �� la membrane cellulaire. En outre, les fonctions augment��es des prot��ines Gi comme d��montr��es par l'amplification de l���inhibition de l'ad��nylate cyclase par les hormones inhibitrices et l'activit�� forskoline (FSK)-stimul��e de l���ad��nylate cyclase par une faible concentration de GTP��S dans les CMLV de SHR ont ��galement ��t�� restaur��es aux niveaux de WKY par le dbcAMP. La prolif��ration accrue des CMLV de SHR a ��galement ��t�� att��nu��e par le dbcAMP et la forskoline, un activateur de l'ad��nylate cyclase. De plus, dbcAMP a restaur�� la production augment��e d'anion superoxyde (O2-), l'activit�� de la NAD(P)H oxydase et l���expression accrue des prot��ines Nox 4 et p47phox observ��e dans les CMLV de SHR jusqu���au niveau contr��le. Par ailleurs, la phosphorylation accrue des PDGF-R, EGF-R, c-Src et ERK1/2 ��nonc��e par les CMLV de SHR a ��galement ��t�� diminu��e par le dbcAMP d'une mani��re d��pendante de concentration. Ces r��sultats sugg��rent que le niveau r��duit d'AMPc intracellulaire montr�� par les CMLV de SHR contribue �� l'expression accrue des prot��ines Gi et �� l���hyperprolif��ration cellulaire �� travers l���augmentation du stress oxydatif, la transactivation des EGF-R, PDGF-R et la voie de signalisation des MAP kinases.

M��canismes mol��culaires de l���hypertrophie vasculaire dans le mod��le animal d���hypertension essentielle (SHR)

La voie de signalisation des phosphoinositides joue un r��le cl�� dans la r��gulation du tonus vasculaire. Plusieurs ��tudes rapportent une production endog��ne de l���angiotensin II (Ang II) et de l���endoth��line-1 (ET-1) par les cellules musculaires lisses vasculaires (CMLVs) de rats spontan��ment hypertendus (spontaneously hypertensive rats : SHR). De plus, l���Ang II exog��ne induit son effet prohypertrophique sur les CMLVs selon un m��canisme d��pendant de la prot��ine Gq�� et de la PKC���. Cependant, le r��le de l���axe Gq��/PLC��/PKC��� dans l���hypertrophie des CMLVs provenant d���un mod��le animal de l���hypertension art��rielle n���est pas encore ��tudi��. L���objectif principal de cette th��se est d���examiner le r��le de l���axe Gq��/PLC��1 dans les m��canismes mol��culaires de l���hypertrophie des CMLVs provenant d���un mod��le animal d���hypertension art��rielle essentielle (spontaneously hypertensive rats : SHR). Nos premiers r��sultats indiquent que contrairement aux CMLVs de SHR ��g��s de 12 semaines (absence d���hypertrophie cardiaque), les CMLVs de SHR ��g��s de 16 semaines (pr��sence d���hypertrophie cardiaque) pr��sentent une surexpression prot��ique endog��ne de Gq�� et de PLC��1 par rapport aux CMLVs de rats WKY appari��s pour l�����ge. L���inhibition du taux d���expression prot��ique de Gq�� et de PLC��1 par des siRNAs sp��cifiques diminue significativement le taux de synth��se prot��ique ��lev�� dans les CMLVs de SHR. De plus, la surexpression endog��ne des Gq�� et PLC��1, l���hyperphosphorylation de la mol��cule ERK1/2 et le taux de synth��se prot��ique ��lev�� dans les CMLVs de SHR de 16 semaines ont ��t�� att��nu��s significativement par des antagonistes des r��cepteurs AT1 (losartan) et ETA (BQ123), mais pas par l���antagoniste du r��cepteur ETB (BQ788). L���inhibition pharmacologique des MAPKs par PD98059 diminue significativement la surexpression endog��ne de Gq��/PLC��1 et le taux de synth��se prot��ique ��lev�� dans les CMLVs de SHR. D���un c��t��, l���inhibition du stress oxydatif (par DPI, inhibiteur de la NAD(P)H oxidase, et NAC , mol��cule anti-oxydante), de la mol��cule c-Src (PP2) et des r��cepteurs de facteurs de croissance (AG1024 (inhibiteur de l���IGF1-R), AG1478 (inhibiteur de l���EGFR) et AG1295 (inhibiteur du PDGFR)) a permis d���att��nuer significativement la surexpression endog��ne ��lev��e de Gq��/PLC��1 et l���hypertrophie des CMLVs de SHR. D���un autre c��t��, DPI, NAC et PP2 att��nuent significativement l���hyperphosphorylation de la mol��cule c-Src, des RTKs (r��cepteurs �� activit�� tyrosine kinase) et de la mol��cule ERK1/2. Dans une autre ��tude, nous avons aussi d��montr�� que la PKC��� montre une hyperphosphorylation en Tyr311 dans les CMLVs de SHR compar��es aux CMLVs de WKY. La rottlerin, utilis��e comme inhibiteur sp��cifique de la PKC���, inhibe significativement cette hyperphosphorylation en Tyr311 d��pendamment de la concentration. L���inhibition de l���activit�� de la PKC��� par la rottlerin a ��t�� aussi associ��e �� une att��nuation significative de la surexpression prot��ique endog��ne de Gq��/PLC��1 et l���hypertrophie des CMLVs de SHR. De plus, l���inhibition pharmacologique de l���activit�� de la PKC���, en amont du stress oxydatif, a permis d���inhiber significativement l���activit�� de la NADPH, le taux de production ��lev��e de l���ion superoxyde ainsi que l���hyperphosphorylation de la mol��cule ERK1/2, de la mol��cule c-Src et des RTKs. �� notre surprise, nous avons aussi remarqu�� une surexpression prot��ique de l���EGFR et de l���IGF-1R dans les CMLVs de SHR �� l�����ge de 16 semaines. L���inhibition pharmacologique de l���activit�� de la PKC���, de la mol��cule c-Src et du stress oxydatif a permis d���inhiber significativement la surexpression prot��ique endog��ne de ces RTKs. De plus, l���inhibition de l���expression prot��ique de l���EGFR et de la mol��cule c-Src par des siRNA sp��cifiques att��nue significativement le taux d���expression prot��ique ��lev�� de Gq�� et de PLC��1 ainsi que le taux de synth��se prot��ique ��lev�� dans les CMLVs de SHR. Des siRNAs sp��cifiques �� la PKC��� ont permis d���att��nuer significativement le taux de synth��se prot��ique ��lev�� dans les CMLVs de SHR et confirment le r��le important de la PKC��� dans les m��canismes mol��culaires de l���hypertrophie des CMLVs selon une voie d��pendante du stress oxydatif. En conclusion, ces r��sultats sugg��rent un r��le important de l���activation endog��ne de l���axe Gq��-PLC��-PKC��� dans le processus d���hypertrophie vasculaire selon un m��canisme impliquant une activation endog��ne des r��cepteurs AT1/ETa, de la mol��cule c-Src, du stress oxidatif, des RTKs et des MAPKs.

Entwicklung und Validierung der Steigbildmethode zur Differenzierung von ausgew��hlten Lebensmitteln aus verschiedenen Anbausystemen und Verarbeitungsprozessen

Zusammenfassung (deutsch) Seit den 1980iger Jahren w��chst die Bedeutung der sog. Bildschaffenden Methoden f��r die Bestimmung der Qualit��t ��kologischer Produkte. Zu diesen Methoden geh��rt die Biokristallisation, Steigbild und Rundfilter-Chromatographie. Die Ergebnisse dieser Methoden sind Bilder, die anhand definierter Kriterien ausgewertet werden. Bei der Biokristallisation sind es mehr oder weniger geordnete Kristallisationen auf einer Glasplatte, bei dem Steigbild zweidimensionale Strukturen auf Chromatographiepapier. In der Vergangenheit wurden die Bilder von Spezialisten ausgewertet, die nach einer l��ngeren Schulung produktspezifische Kriterien entwickelt hatten. Im Gegensatz zur D��nnschicht-Chromatographie, wo der einzelne Stoff von der Matrix separiert wird, ist das Ziel beim Steigbild, Strukturen der m��glichst ganzen Probe zu erzeugen. Die Methode wurde von Kolisko in den 1929iger Jahren entwickelt, wobei eine Kombination aus Chromatographieprozess und Metallkomplexreaktionen genutzt wurde. Die Firma WALA entwickelte die Methode f��r die Kontrolle ihrer Produkte und setze Silbernitrat und Eisensulfat ein. Bisher wurde die Methode qualitativ beschreibend ausgewertet, wobei einzelne Bildelemente und deren Interaktion beschrieben wurden. Deshalb musste f��r die vorliegende Arbeit Auswertungsmethoden entwickelt werden, mit denen auch eine statistische Bearbeitung der Ergebnisse m��glich ist (nominale Unterscheidung von proben anhand der Bilder). Die Methode wurde bisher in einer Reihe von Studien eingesetzt (u.a. die Unterscheidung von Produktionsweisen). Obwohl die Bilder nur qualitativ ausgewertet wurden, konnten geschulte Pr��fpersonen Proben aus verschiedenen Anbausystemen anhand der Bilder trennen. Die Ergebnisse wurden aber nicht so dokumentiert, dass sie den Erfordernissen internationaler Standardnormen f��r Laboratorien gen��gten. Deshalb mussten f��r diese Arbeit zun��chst die Prozeduren dokumentiert und eine systematische Untersuchung zu den Einflussgr����en durchgef��hrt werden. Dazu wurde die visuelle Bildauswertung entwickelt und standardisiert. Die visuelle Bildauswertung basiert auf morphologischen Kriterien der Bilder von den untersuchten Weizen- und M��hrenproben. Ein Panel aus geschulten Personen entwickelte dann die Kriterien und legte sie anhand von Referenzbildern fest. Die Bilder der vorliegenden Arbeit wurden mit der einfach beschreibenden Pr��fung ausgewertet, wie sie aus der sensorischen Pr��fung von Lebensmitteln ��bernommen werden konnte. Mit geschulten und ungeschulten Pr��fpersonen wurden Weizenproben und verschiedene M��hrens��fte mit der sog. Dreieckspr��fung ausgewertet (von ISO 4120). Alle Laborprozeduren wurden dokumentiert. Mit der Anwendung dieser Prozeduren wurden Vergleichsversuche mit Laboren in D��nemark und Holland (BRAD, LBI) durchgef��hrt. Die Ergebnisse waren sowohl f��r Weizen- als auch f��r M��hrenproben vergleichbar, wobei alle drei Labore zwischen jeweils zwei Proben unterscheiden konnten. Die systematische Untersuchung zu den Einflussgr����en zeigte, dass das Unterscheidungsverm��gen der Methode vor allem von den klimatischen Bedingungen w��hrend der Steigphasen beeinflusst wird. Auch die Pr��konditionierung der Papiere hat einen gro��en Einfluss, w��hrend die Wasserqualit��t (ultra-filtriert, de-ionisiert, destilliert) eine untergeordnete Bedeutung hat. F��r Weizen- und M��hrenproben wurde sowohl die Wiederholbarkeit als auch die Reproduzierbarkeit getestet. Die Unterschiede in den Bildern der verschiedenen Proben waren dabei immer gr����er als die Variation durch Proben- und Bildwiederholung und das Labor. Die so charakterisierte Methode wurde auf kodierte Proben von definierten Feldversuchen und auf Marktproben (Paarvergleich von Anbausystemen ��kologisch und konventionell) angewandt, wobei als Ergebnis mehr als 90% der Proben mit der einfach beschreibenden Pr��fung anhand der Bilder unterschieden werden konnten. Die Auswertung mit der Dreieckspr��fung zeigte, dass sowohl Sorten und Verarbeitungsschritte (Saft) als auch Anbauweisen signifikant getrennt wurden. Dar��ber hinaus wurde die Methode auch erfolgreich auf Apfelproben angewandt. Weitere Untersuchungen m��ssen zeigen, ob sich das Potential der Methode, verschiedene Fragen wie die Authentizit��tspr��fung von Lebensmitteln verifizieren lassen.

La m??sica d'enconar : vint-i-cinqu?? aniversari de l'Escola de M??sica (M??tode Ireneu Segarra) de Palma o la maduresa d'un projecte centrat en l'educaci??. 'La m??sica de paladear : vig??simo quinto aniversario de la Escuela de M??sica (M??todo Ireneu Segarra) de Palma o la madurez de un proyecto centrado en la educaci??n'

Resumen tomado de la publicaci??n

Las actuaciones municipales en Catalu��a en el ��mbito de la inmigraci��n.

Resumen tomado del documento