1000 resultados para Notch stress


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As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. YeastCUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study,CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.

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Ethanol abuse is linked to several acute and chronic injuries that can lead to health problems. Ethanol addiction is one of the most severe diseases linked to the abuse of this drug. Symptoms of ethanol addiction include compulsive substance intake and withdrawal syndrome. Stress exposure has an important role in addictive behavior for many drugs of abuse (including ethanol), but the consequences of stress and ethanol in the organism when these factors are concomitant results in a complex interaction. We investigated the effects of concomitant, chronic administration of ethanol and stress exposure on the withdrawal and consumption of, as well as the preference for, ethanol in mice. Male Swiss mice (30–35 g, 8-10 per group) were exposed to an ethanol liquid diet as the only source of food for 15 days. In the final 5 days, they were exposed to forced swimming stress. Twelve hours after removal of the ethanol liquid diet, animals were evaluated for ethanol withdrawal by measuring anxiety-related behaviors and locomotor activity. Twenty-four hours after evaluation of ethanol withdrawal, they were evaluated for voluntary consumption of ethanol in a “three-bottle choice” paradigm. Mice exposed to chronic consumption of ethanol had decreased locomotor activity during withdrawal. Contrary to our expectations, a concomitant forced swimming stress did not aggravate ethanol withdrawal. Nevertheless, simultaneous ethanol administration and stress exposure increased voluntary consumption of ethanol, mainly solutions containing high concentrations of ethanol. These results showed that stressful situations during ethanol intake may aggravate specific addiction-related behaviors.

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(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABAA receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.

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The aim of this research was to develop a piping stress analysis guideline to be widely used in Neste Jacobs Oy’s domestic and foreign projects. The company’s former guideline to performing stress analysis was partial and lacked important features, which were to be fixed through this research. The development of the guideline was based on literature research and gathering of existing knowledge from the experts in piping engineering. Case study method was utilized by performing stress analysis on an existing project with help of the new guideline. Piping components, piping engineering in process industry, and piping stress analysis were studied in the theory section of this research. Also, the existing piping standards were studied and compared with one another. By utilizing the theory found in literature and the vast experience and know-how collected from the company’s employees, a new guideline for stress analysis was developed. The guideline would be widely used in various projects. The purpose of the guideline was to clarify certain issues such as which of the piping would have to be analyzed, how are different material values determined and how will the results be reported. As a result, an extensive and comprehensive guideline for stress analysis was created. The new guideline more clearly defines formerly unclear points and creates clear parameters to performing calculations. The guideline is meant to be used by both new and experienced analysts and with its aid, the calculation process was unified throughout the whole company’s organization. Case study was used to exhibit how the guideline is utilized in practice, and how it benefits the calculation process.

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Utvecklingen av flercelliga organismer är en mångfacetterad process som kräver kommunikation celler emellan. Under utvecklingen av en organism måste cellerna göra vissa val, vilket bestämmer riktningen för deras fortsatta utveckling. Utgående från dessa val erhåller cellerna egenskaper som är karaktäristiska för olika celltyper. Notch-signalräckan är en viktig reglerare av valet mellan olika cellöden. Notch-signalräckan aktiveras när Notch-receptorer som uttrycks på ytan av en cell binder till Notch-ligander som uttrycks på ytan av en annan närliggande cell. Denna avhandling belyser mekanismerna som reglerar omsättningen av såväl Notch-receptorer som -ligander till och från cellmembranen, samt ökar förståelsen för hur dessa mekanismer påverkar Notch-medierade cellöden i stamceller. Internalisering av Notch receptorer anses nödvändigt för fullständig aktivering av Notch-signalvägen. De bakomliggande molekylära mekanismerna är dock fortfarande oklara. Vi har upptäckt att atypiskt protein kinas Cζ (aPKCζ) reglerar internaliseringen av Notch-receptorer. aPKCζ fosforylerar Notch, vilket leder till receptorns internalisering, men effekten är beroende av receptorns signaleringsstatus. Vi visar att aPKCζ reglerar Notch-signaleringen och styr både neuroners och muskelcellers differentiering. Ytterligare har vi analyserat samspelet mellan cellskelettet och Notch-signalvägen. Våra resultat visar att intermediärfilamenten, en del av cellskelettet, är viktiga reglerare av Notch-signaleringen både under neuronal och vaskulär utveckling. Intermediärfilamenten vimentin och GFAP reglerar uttrycket av Notch-ligander vid cellmembranen i hjärnans stödceller, astrocyterna, och påverkar därmed neuronala stamcellers cellödesbeslut. Vimentin är även viktigt reglerare av Notch-signalräckan vid angiogenesen. Celler som saknar vimentin uppvisar avvikande Notch-signalering emedan möss som saknar vimentin påvisar en fördröjd utveckling av vaskulaturen under embryonalstadiet. ------------------------------------------------- Monisoluisten organismien kehittyminen on monimutkainen prosessi, joka vaatii viestintää solujen välillä. Kehittymisen aikana solut joutuvat tiettyjen valintojen eteen, mitkä tulevat määrittämään niiden erilaistumisen suunnan. Solut omaksuvat solutyypille ominaisia ominaisuuksia näihin valintoihin perustuen Notch-signalointireitti säätelee solujen erilaistumista eri suuntiin. Notch-signalointireitti aktivoituu, kun Notch-reseptori yhden solun pinnalla sitoo Notch-ligandin toisen, viereisen solun solukalvolla. Tutkimukseni lisää tuntemusta Notch-reseptoreiden ja ligandien solun sisäisestä liikennöinnistä ja sitä säätelevistä mekanismeista, sekä tämän säätelyn vaikutuksista kantasulojen erilaistumiseen. Notch-signalointireitin aktivoituminen vaatii reseptoreiden ja ligandien sisäistämisen solukalvolta, mutta taustalla olevat ja sisäistymistä säätelevät mekanismit ovat vielä epäselviä. Tutkimukseni osoittaa, että atyyppinen proteiinikinaasi Cζ (aPKCζ) säätelee Notch-reseptoreiden endosytoosia. Endosytoosin lopputulos riippuu siitä onko reseptori aktivoitunut ligandin välityksellä vai ei. Tuloksemme osoittavat aPKCζ säätelevän Notch-signalointia ja kontrolloivan sekä hermosolujen, että lihassolujen erilaistumista. Analysoimme myös Notch-signaloinnin ja solun tukirangan vuorovaikutuksia. Välikokoiset filamentit, jotka ovat osa tukirankaa, säätelevät Notch-signalointia neuronaalisen erilaistumisen sekä verisuonten uudismuodostumisen aikana. Vimentiini ja GFAP ovat välikokoisia säikeitä, jotka säätelevät Notch-ligandien ekspressiota astrosyyttien, eli aivojen hermotukisolujen solukalvolla. Vimentiini säätelee myös Notch-signalointireittiä angiogeneesin aikana. Vimentiiniä vailla olevilla soluilla ilmenee heikentynyttä Notch-signalointia, joka voidaan liittää hiirillä ilmenevään vimenttiinin puutteesta johtuvaan viivästyneeseen verisuonien kehitykseen.

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Brazil is the second soybean (Glycine max L. Merrill) producer and exporter in the world. In 2005, soybean cultivated in the southeastern region of the country suffered drought stress imposed by adverse high temperatures and low humidity during its reproductive stage. Little information is available regarding the effect of drought stress on the quality of grains. In this study chemical and biochemical characteristics of five soybean samples belonging to three different cultivars grown under drought stress were evaluated. The samples did not meet standards for marketing and contained high amounts of green seeds. Grains were analyzed for appearance, 100 seed weight, humidity, water activity, proteins, lipids, lipoxygenase 1 activity, peroxides, and pigment contents after harvest and after 20 months of storage at room temperature. Acidity was measured also after 30 months of storage. The values of water activity and humidity were 0.6-0.7 and 8.7-11.9%, respectively, and they did not change during storage time, but there was an increase in acidity, which alludes to lipase activity. The activity of lipoxygenase 1 was greatly affected. Immediately after harvest, the green pigments were represented mainly by pheophytin a, followed by pheophytin b, small quantities of chlorophyll b and chlorophyll a, and traces of other chlorophyll derivatives. After 20 months of storage almost all green pigments had disappeared. Drought stress probably enhanced membrane permeability, which led to a lower pH and promoted transformation of chlorophylls to pheophytins.

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White tea is an unfermented tea made from young shoots of Camellia sinensis protected from sunlight to avoid polyphenol degradation. Although its levels of catechins are higher than those of green tea (derived from the same plant), there are no studies addressing the relationship between this tea and obesity associated with oxidative stress.The objective of this study was to evaluate the effect of white tea on obesity and its complications using a diet induced obesity model. Forty male C57BL/6 mice were fed a high-fat diet to induce obesity (Obese group) or the same diet supplemented with 0.5% white tea extract (Obese + WTE) for 8 weeks. Adipose tissue, serum lipid profile, and oxidative stress were studied. White tea supplementation was not able to reduce food intake, body weight, or visceral adiposity. Similarly, there were no changes in cholesterol rich lipoprotein profile between the groups. A reduction in blood triacylglycerols associated with increased cecal lipids was observed in the group fed the diet supplemented with white tea. White tea supplementation also reduced oxidative stress in liver and adipose tissue. In conclusion, white tea extract supplementation (0.5%) does not influence body weight or adiposity in obese mice. Its benefits are restricted to the reduction in oxidative stress associated with obesity and improvement of hypertriacylglycerolemia.

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Lipid micro and nanoparticles have been extensively investigated as carriers for hydrophobic bioactives in food systems because they can simultaneously increase the dispersibility of these lipophilic substances and help improve their bioavailability. In this study, lipid microparticles of babacu oil and denatured whey protein isolate were produced, and their ability to protect quercetin against degradation was evaluated over 30 days of storage. Additionally, the lipid microparticles were subjected to the typical stress conditions of food processing (presence of sucrose, salt, and thermal stresses), and their physico-chemical stability was monitored. The data show that the babacu microparticles efficiently avoided the oxidation of quercetin because 85% of the initial amount of the flavonoid was preserved after 30 days. The particles were notably stable up to a temperature of 70 °C for 10 minutes at relatively high concentrations of salt and sucrose. The type of stirring (mechanical or magnetic) also strongly affected the stability of the dispersions.

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Strenx® 960 MC is a direct quenched type of Ultra High Strength Steel (UHSS) with low carbon content. Although this material combines high strength and good ductility, it is highly sensitive towards fabrication processes. The presence of stress concentration due to structural discontinuity or notch will highlight the role of these fabrication effects on the deformation capacity of the material. Due to this, a series of tensile tests are done on both pure base material (BM) and when it has been subjected to Heat Input (HI) and Cold Forming (CF). The surface of the material was dressed by laser beam with a certain speed to study the effect of HI while the CF is done by bending the specimen to a certain angle prior to tensile test. The generated results illustrate the impact of these processes on the deformation capacity of the material, specially, when the material has HI experience due to welding or similar processes. In order to compare the results with those of numerical simulation, LS-DYNA explicit commercial package has been utilized. The generated results show an acceptable agreement between experimental and numerical simulation outcomes.

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This work aimed to evoluate physiological response of cowpea (Vigna unguiculata L. Walp) seeds submitted to salt stress. Seeds of cultivars 'Epace-10'; 'Canapu' and 'Pitiúba' of cowpea, were submitted to germination test in germinator at 25(0)C, in "germitest" papers imbibed in distilled water or in 0, 10, 50, 100 and 200mol m-3 NaCl solutions. At the first and second counting of the germination test, normal seedlings were accounted, weighted and dried, obtaining data for vigor, total germination, fresh matter weight and dry matter weight. The seedlings hypocotyls, root and total length were measured total proteins content in cotyledons were obtained from germinating seeds. The presence of salt at concentrations higher than 50mol m-3 NaCl affect the germination, seedlings growth and cotyledons total protein synthesis of all cowpea cultivars. The seeds of cultivar pitiúba were is more tolerant to salinity, than the cultivars Canapu and Epace-10.

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The objective of this experiment was to determine the influence of different salt levels (zero, 15, 30, 45 and 60mM NaCl) on seed physiological quality of two wheat cultivars (BRS 177 and BRS 179). SUMMARIZE METHODOLOGY. The results allow the following conclusions: the physiological quality (germination and vigor) of wheat seeds, cultivars BRS 179 and BRS 177, decrease with the increase of the salinity. The wheat seeds cv. BRS 179 performs better than BRS 177, mainly in higher salt concentrations (³ 45mM of NaCl). The electric conductivity of wheat seeds increases in function of the increment of the saline concentrations.

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The objective of the experiments was to determine the influence of the effects of different salt levels (zero, 15, 30, 45 and 60mM NaCl) on the physiological quality of seeds of two barley cultivars (BRS 195 and AF 98067). Assays were conducted to evaluate salt stress on germination and vigor. The germination and germination rate of the barley seeds decreased as salt levels increased, reducing the seed viability and vigor. The salinity affected the membrane integrity, mainly in AF 98067 that showed more sensitivity to salt stress.

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Excess salts in the root zone inhibit water uptake by plants, affect nutrient uptake and may result in toxicities due to individual salts in the soil solution. Excess exchangeable sodium in the soil may destroy the soil structure to a point where water penetration and root aeration become impossible. Sodium is also toxic to many plants. Beans (Phaseolus vulgaris L.) are consumed as protein source in northeastern Brazil, although little is known about common bean cultivar tolerance to salinity. The germination of bean cultivars under salt stress was studied. The cultivars 'Carioca' and 'Mulatinho' were submitted to germination test in a germinator at 25ºC, at the Seed Analysis Laboratory of the Brazilian Agricultural Research Corporation unit in the Semi- Arid region (Embrapa Semi Árido), Petrolina, Pernambuco State. These seeds were germinated on "germitest" papers imbibed in distilled water or in 10, 50, 100 e 200 mol.m-3sodium chloride (NaCl) solutions. At the first and second counts of the germination test, normal seedlings were counted, measured, weighed and dried, supplying data for vigor, total germination, fresh matter weight and dry matter weight and seedlings length. Total protein was quantified in cotyledons at 3, 6 and 9 days after sowing. The results indicated that the NaCl content influenced seed germination and concentrations above 50 mol.m-3 decreased germination and seedling growth.