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In vitro maturation of porcine oocyte: effects of lipid manipulation on fertilization, embryo development and cryo-resistance

Prates, Elsa Cristina da Graça
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
27.35%
Os objectivos desta tese foram implementar a técnica de produção in vitro de embriões de suíno e investigar os efeitos da modulação lipídica durante a maturação in vitro (MIV) usando o isómero trans-10,cis-12 do ácido linoleico conjugado (t10,c12 CLA) e a forscolina. A modulação lipídica durante a MIV induziu alterações na morfologia do oócito e perfil em ácidos gordos (AG)/ plasmalogénios dos complexos cumulus-oócito. Após 44 h de suplementação com t10,c12 CLA ocorreu aclaramento citoplásmico mas a taxa de blastocistos diminuiu. A suplementação em períodos longos com forscolina poderá reduzir o crescimento do oócito, a progressão nuclear e a capacidade fertilizante, ou apenas interferir na morfologia e composição das gotas lipídicas (2 h de suplementação). Os dois suplementos em simultâneo melhoraram a taxa de maturação. Apesar das alterações na composição em AG/ plasmalogénios dos oócitos tratados, não se detetaram efeitos sobre a crio-resistência dos blastocistos; ABSTRACT: The purpose of this thesis was to implement the in vitro technique for porcine embryo production and to investigate the effects of lipid content modulation during oocyte in vitro maturation (IVM) using trans-10...

Milk composition during duodenal infusion of conjugated linoleic acid in dairy goats fed diets with different C18:2/C18:1 ratios

Schmidely,Ph; Andrade,P.V.D
Fonte: Universidade Federal de Minas Gerais, Escola de Veterinária Publicador: Universidade Federal de Minas Gerais, Escola de Veterinária
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2011 EN
Relevância na Pesquisa
27.35%
O efeito do t10,c12-C18:2 na produção de leite e no perfil em ácidos graxos (AG) da gordura do leite foi estudado em oito cabras que receberam t10,c12-C18:2 por infusão duodenal (ácido linoléico conjugado -CLA, 2g/10 h) durante três dias, seguido por dois dias de infusão de leite desnatado (SM). As cabras foram distribuídas em quatro grupos em um delineamento fatorial 2x2: duas porcentagens de concentrado da dieta - L, baixa 45% ou H, alta 65% - e dois tipos de gordura adicionada para modificar a relação c9,c12-C18:2/c9-C18:1 da dieta - grãos de soja ou de canola. Amostras de leite foram coletadas antes (basal) e durante a infusão de CLA e de leite desnatado. Ingestão de matéria seca, teor e produção de gordura, de proteína e de lactose foram semelhantes antes do início e durante a infusão de CLA. A proporção de AG saturados com 4 a 8C ou 10 a 15C não foi alterada durante a infusão de CLA. Independentemente da alimentação das cabras, a infusão de CLA aumentou as proporções de C18:0, t10- e t11-C18:1 e diminuiu as de c9-C18:1 e c9,t11-C18:2 na gordura do leite. O CLA diminuiu as relações c9-C18:1/C18:0 e c9,t11-C18:2/t11-C18:1 no leite dos quatro grupos experimentais. Os resultados mostraram que a lipogênese mamária em cabras leiteiras não foi alterada por 2g/d de t10...

Use of metabolism and swimming activity to evaluate the sublethal toxicity of surfactant (LAS-C12) on Mugil platanus

Barbieri,Edison
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
Relevância na Pesquisa
27.01%
This study aimed to investigate the toxicological effects of the LAS-C12 on Mugil platanus (mullet). Fishes exposed to 1.0 mg.L-1 for 24, 48, 72, 96 and 120 hours presented significant increase in specific routine metabolism. At the concentration of 0.5 mgL-1, the active metabolism presented a decreasing trend from 48 h of exposure on. However, only the consumption averages for 72 h were statistically different from the ones obtained for other periods of exposure. The lowest oxygen consumption in this concentration was observed for 24, 48 and 72 hours of exposure. Significant differences between the control and the concentration of 2.5 mgL-1 were observed for the different periods of exposure. It was not possible to measure the consumption of oxygen for 96 and 120 h, because the fishes got tired in less than one minute after they were placed in the respirometer. The time of swimming until exhausted for fish exposed to 2.5 mgL-1 of LAS-C12 for 24 h was 8 minutes. Following 72 hours of exposure to this concentration, the fish got exhausted after 3 minutes.

Use of fluorescein-di-beta-D-galactopyranoside (FDG) and C12-FDG as substrates for beta-galactosidase detection by flow cytometry in animal, bacterial, and yeast cells.

Plovins, A; Alvarez, A M; Ibañez, M; Molina, M; Nombela, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1994 EN
Relevância na Pesquisa
27.28%
Fluorescein-di-beta-D-galactopyranoside (FDG) was found to be a useful substrate for beta-galactosidase detection by flow cytometry in gram-negative bacteria, since it entered viable cells and gave a fluorescence emission proportional to the enzymatic activity. C12-FDG, a more lipophilic derivative, gave a very poor signal because of the lack of penetration. On the contrary, C12-FDG was more sensitive than FDG for beta-galactosidase activity determinations in animal cells. In contrast to previous reports, C12-FDG did not enter viable yeast cells, so that the use of the substrate required cell permeabilization. Without this treatment, C12-FDG penetrates only nonviable yeast cells that may occur in populations expressing beta-galactosidase.

Apoptosis induced by t10,c12-conjugated linoleic acid is mediated by an atypical endoplasmic reticulum stress response*

Ou, Lihui; Wu, Yue; Ip, Clement; Meng, Xiaojing; Hsu, Yung-Chun; Ip, Margot M.
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Publicado em /05/2008 EN
Relevância na Pesquisa
27.49%
Conjugated linoleic acid (CLA) inhibits rat mammary carcinogenesis, in part by inducing apoptosis of preneoplastic and neoplastic mammary epithelial cells. The current study focused on the mechanism by which apoptosis is induced. In TM4t mammary tumor cells, trans-10,cis-12 (t10,c12)-CLA induced proapoptotic C/EBP-homologous protein (CHOP) concurrent with the cleavage of poly(ADP-ribose) polymerase. Knockdown of CHOP attenuated t10,c12-CLA-induced apoptosis. Furthermore, t10,c12-CLA induced the cleavage of endoplasmic reticulum (ER)-resident caspase-12, and a selective inhibitor of caspase-12 significantly alleviated t10,c12-CLA-induced apoptosis. Using electron microscopy, we observed that t10,c12-CLA treatment resulted in marked dilatation of the ER lumen. Together, these data suggest that t10,c12-CLA induces apoptosis through ER stress. To further explore the ER stress pathway, we examined the expression of the following upstream ER stress signature markers in response to CLA treatment: X-box binding protein 1 (XBP1) mRNA (unspliced and spliced), phospho-eukaryotic initiation factor (eIF) 2α, activating transcription factor 4 (ATF4), and BiP proteins. We found that t10,c12-CLA induced the expression and splicing of XBP1 mRNA as well as the phosphorylation of eIF2α. In contrast...

Hepatic retinol secretion and storage are altered by dietary CLA: common and distinct actions of CLA c9,t11 and t10,c12 isomers[S]

Ortiz, Berenice; Wassef, Lesley; Shabrova, Elena; Cordeddu, Lina; Banni, Sebastiano; Quadro, Loredana
Fonte: The American Society for Biochemistry and Molecular Biology Publicador: The American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Publicado em /11/2009 EN
Relevância na Pesquisa
27.35%
Conjugated linoleic acid (CLA) is a polyunsaturated fatty acid obtained from ruminant products. Previous studies in rats and pigs showed that a dietary equimolar mixture of c9,t11 and t10,c12 CLA isomers induces changes in serum and tissue levels of retinoids (vitamin A derivatives). However, the mechanism(s) responsible for these actions remain(s) unexplored. Given the numerous crucial biological functions regulated by retinoids, it is key to establish whether the perturbations in retinoid metabolism induced by dietary CLA mediate some of the beneficial effects associated with intake of this fatty acid or, rather, have adverse consequences on health. To address this important biological question, we began to explore the mechanisms through which dietary CLA alters retinoid metabolism. By using enriched preparations of CLA c9,t11 or CLA t10,c12, we uncoupled the effects of these two CLA isomers on retinoid metabolism. Specifically, we show that both isomers induce hepatic retinyl ester accumulation. However, only CLA t10,c12 enhances hepatic retinol secretion, resulting in increased serum levels of retinol and its specific carrier, retinol-binding protein (RBP). Dietary CLA t10,c12 also redistributes retinoids from the hepatic stores toward the adipose tissue and possibly stimulates hepatic retinoid oxidation. Using mice lacking RBP...

The t10,c12 isomer of conjugated linoleic acid stimulates mammary tumorigenesis in transgenic mice overexpressing erbB2 in the mammary epithelium

Ip, Margot M.; McGee, Sibel O.; Masso-Welch, Patricia A.; Ip, Clement; Meng, Xiaojing; Ou, Lihui; Shoemaker, Suzanne
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.54%
Conjugated linoleic acid (CLA), a family of isomers of octadecadienoic acid, inhibits rat mammary carcinogenesis, angiogenesis, and lung metastasis from a transplantable mammary tumor. c9,t11-CLA, the predominant isomer in dairy products, and t10,c12-CLA, a component of CLA supplements, are equally effective. The objective of the current studies was to test the efficacy of these two CLA isomers in a clinically relevant breast cancer model. Transgenic mice overexpressing erbB2 in the mammary epithelium were fed control or 0.5% CLA-supplemented diets continuously from weaning. Unexpectedly, t10,c12-CLA stimulated lobular hyperplasia of the mammary epithelium and accelerated mammary tumor development, decreasing median tumor latency to 168 days of age compared to 256 and 270 days in the c9,t11-CLA and control groups, respectively. Metastasis was also increased by t10,c12-CLA, with percent of tumor-bearing mice with lung metastasis 73%, 14%, and 31%, in the t10,c12-CLA, c9,t11-CLA and control groups, respectively. A second study, in which CLA administration was initiated after puberty, confirmed the stimulatory effect of t10,c12-CLA on mammary tumor development and metastasis. Additionally, t10,c12-CLA, but not c9,t11-CLA, increased the size of the liver...

t10,c12-Conjugated linoleic acid stimulates mammary tumor progression in Her2/ErbB2 mice through activation of both proliferative and survival pathways

Meng, Xiaojing; Shoemaker, Suzanne F.; McGee, Sibel O.; Ip, Margot M.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.35%
The t10,c12 isomer of conjugated linoleic acid (CLA) inhibits rat mammary carcinogenesis, metastasis from a transplantable mouse mammary tumor and angiogenesis; however, it stimulates mammary tumorigenesis in transgenic mice overexpressing ErbB2 in the mammary epithelium (ErbB2 transgenic mice). In the current study, we report that a 4-week supplementation of the diet with 0.5% trans-10, cis-12 conjugated linoleic acid (t10,c12-CLA) stimulated the growth of established ErbB2-overexpressing mammary tumors by 30% and increased the number of new tumors from 11% to 82%. Additionally, when t10,c12-CLA supplementation of ErbB2 transgenic mice was initiated at 21 weeks of age, a time just prior to tumor appearance, overall survival was decreased from 46.4 weeks in the control to 39.0 weeks in the CLA group, and survival after detection of a palpable tumor from 7.5 to 4.6 weeks. Short-term supplementation from 10 to 14 weeks or 21 to 25 weeks of age temporarily accelerated tumor development, but over the long term, there was no significant effect on mammary tumorigenesis. Long term as well as a short 4-week supplementation increased mammary epithelial hyperplasia and lobular development, and altered the mammary stroma; this was reversible in mice returned to the control diet. t10...

Dietary t10,c12-CLA but not c9,t11 CLA Reduces Adipocyte Size in the Absence of Changes in the Adipose Renin–Angiotensin System in fa/fa Zucker Rats

DeClercq, Vanessa; Zahradka, Peter; Taylor, Carla G.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.17%
In obesity, increased activity of the local renin–angiotensin system (RAS) and enlarged adipocytes with altered adipokine production are linked to the development of obesity-related health problems and cardiovascular disease. Mixtures of conjugated linoleic acid (CLA) isomers have been shown to reduce adipocyte size and alter the production of adipokines. The objective of this study was to investigate the effects of feeding individual CLA isomers on adipocyte size and adipokines associated with the local adipose RAS. Male fa/fa Zucker rats received either (a) control, (b) cis(c)9,trans(t)11-CLA, or (c) t10,c12-CLA diet for 8 weeks. The t10,c12-CLA isomer reduced adipocyte size and increased cell number in epididymal adipose tissue. RT-PCR and Western blot analysis revealed that neither CLA isomer altered mRNA or protein levels of angiotensinogen or AngII receptors in adipose tissue. Likewise, levels of the pro-inflammatory cytokines TNF-α and IL-6 or the anti-inflammatory cytokine IL-10 were unchanged in adipose tissue. Similarly, neither CLA isomer had any effect on phosphorylation nor DNA binding of NF-κB. Our results suggest that although the t10,c12-CLA isomer had beneficial effects on reducing adipocyte size in obese rats...

The Pseudomonas aeruginosa Autoinducer 3O-C12 Homoserine Lactone Provokes Hyperinflammatory Responses from Cystic Fibrosis Airway Epithelial Cells

Mayer, Matthew L.; Sheridan, Jared A.; Blohmke, Christoph J.; Turvey, Stuart E.; Hancock, Robert E. W.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 31/01/2011 EN
Relevância na Pesquisa
27.41%
The discovery of novel antiinflammatory targets to treat inflammation in the cystic fibrosis (CF) lung stands to benefit patient populations suffering with this disease. The Pseudomonas aeruginosa quorum sensing autoinducer N-3-oxododecanoyl homoserine lactone (3O-C12) is an important bacterial virulence factor that has been reported to induce proinflammatory cytokine production from a variety of cell types. The goal of this study was to examine the ability of 3O-C12 to induce proinflammatory cytokine production in normal and CF bronchial epithelial cells, and better understand the cellular mechanisms by which this cytokine induction occurs. 3O-C12 was found to induce higher levels of IL-6 production in the CF cell lines IB3-1 and CuFi, compared to their corresponding control cell lines C38 and NuLi. Systems biology and network analysis revealed a high predominance of over-represented innate immune pathways bridged together by calcium-dependant transcription factors governing the transcriptional responses of A549 airway cells to stimulation with 3O-C12. Using calcium-flux assays, 3O-C12 was found to induce larger and more sustained increases in intracellular calcium in IB3-1 cells compared to C38, and blocking this calcium flux with BAPTA-AM reduced the production of IL-6 by IB3-1 to the levels produced by C38. These data suggest that 3O-C12 induces proinflammatory cytokine production in airway epithelial cells in a calcium-dependent manner...

Bioprocess development for the production of mouse-human chimeric anti-epidermal growth factor receptor vIII antibody C12 by suspension culture of recombinant Chinese hamster ovary cells

Hu, Suwen; Deng, Lei; Wang, Huamao; Zhuang, Yingping; Chu, Ju; Zhang, Siliang; Li, Zhonghai; Guo, Meijin
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.41%
The mouse-human chimeric anti-epidermal growth factor receptor vIII (EGFRvIII) antibody C12 is a promising candidate for the diagnosis of hepatocellular carcinoma (HCC). In this study, 3 processes were successfully developed to produce C12 by cultivation of recombinant Chinese hamster ovary (CHO-DG44) cells in serum-free medium. The effect of inoculum density was evaluated in batch cultures of shaker flasks to obtain the optimal inoculum density of 5 × 105 cells/mL. Then, the basic metabolic characteristics of CHO-C12 cells were studied in stirred bioreactor batch cultures. The results showed that the limiting concentrations of glucose and glutamine were 6 and 1 mM, respectively. The culture process consumed significant amounts of aspartate, glutamate, asparagine, serine, isoleucine, leucine, and lysine. Aspartate, glutamate, asparagine, and serine were particularly exhausted in the early growth stage, thus limiting cell growth and antibody synthesis. Based on these findings, fed-batch and perfusion processes in the bioreactor were successfully developed with a balanced amino acid feed strategy. Fed-batch and especially perfusion culture effectively maintained high cell viability to prolong the culture process. Furthermore, perfusion cultures maximized the efficiency of nutrient utilization; the mean yield coefficient of antibody to consumed glucose was 44.72 mg/g and the mean yield coefficient of glutamine to antibody was 721.40 mg/g. Finally...

A Novel Compound C12 Inhibits Inflammatory Cytokine Production and Protects from Inflammatory Injury In Vivo

Wang, Yi; Yu, Congcong; Pan, Yong; Li, Jianling; Zhang, Yali; Ye, Faqing; Yang, Shulin; Zhang, Hui; Li, Xiaokun; Liang, Guang
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 08/09/2011 EN
Relevância na Pesquisa
27.49%
Inflammation is a hallmark of many diseases. Although steroids and cyclooxygenase inhibitors are main anti-inflammatory therapeutical agents, they may cause serious side effects. Therefore, developing non-steroid anti-inflammatory agents is urgently needed. A novel hydrosoluble compound, C12 (2,6-bis(4-(3-(dimethylamino)-propoxy)benzylidene)cyclohexanone), has been designed and synthesized as an anti-inflammatory agent in our previous study. In the present study, we investigated whether C12 can affect inflammatory processes in vitro and in vivo. In mouse primary peritoneal macrophages, C12 potently inhibited the production of the proinflammatory gene expression including TNF-α, IL-1β, IL-6, iNOS, COX-2 and PGE synthase. The activity of C12 was partly dependent on inhibition of ERK/JNK (but p38) phosphorylation and NF-κB activation. In vivo, C12 suppressed proinflammatory cytokine production in plasma and liver, attenuated lung histopathology, and significantly reduced mortality in endotoxemic mice. In addition, the pre-treatment with C12 reduced the inflammatory pain in the acetic acid and formalin models and reduced the carrageenan-induced paw oedema and acetic acid-increased vascular permeability. Taken together, C12 has multiple anti-inflammatory effects. These findings...

A single dose of c9,t11 or t10,c12 conjugated linoleic acid isomers perturbs vitamin A metabolism in mice

Giordano, Elena; Banni, Sebastiano; Quadro, Loredana
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/2011 EN
Relevância na Pesquisa
27.17%
Conjugated linoleic acid (CLA) is a polyunsaturated fatty acid that has numerous biological activities. Previous studies in rodents demonstrated that chronic intake of CLA t10,c12 or CLA c9,t11 isomers perturbs the metabolism of retinoids (vitamin A and its derivatives). Specifically, while both isomers increased liver retinoid levels, only CLA t10,c12 also stimulated hepatic retinol secretion into the bloodstream. Given that retinoid homeostasis in mammalian serum and tissues is crucial to maintain health, it is important to gain more insights into the mode of action of this nutrient-nutrient interaction. Here we hypothesized that an acute administration of either CLA isomer may also influence vitamin A metabolism. By gavaging wild-type and retinol-binding protein (RBP) knockout mice with an oral bolus of radiolabeled retinol containing one of these two isomers, we showed that both CLA t10,c12 and CLA c9,t11 rapidly enhance hepatic uptake of dietary vitamin A and its re-secretion from the liver in the form of retinol bound to RBP. Indeed, in mice lacking this protein, the sole specific carrier for retinol in the circulation, this latter effect was blunted. Also, by using a pharmacological inhibitor of the clearance of chylomicrons...

Enhancement of Palmarumycins C12 and C13 Production in Liquid Culture of Endophytic Fungus Berkleasmium sp. Dzf12 after Treatments with Metal Ions

Mou, Yan; Luo, Haiyu; Mao, Ziling; Shan, Tijiang; Sun, Weibo; Zhou, Kaiyi; Zhou, Ligang
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 07/01/2013 EN
Relevância na Pesquisa
27.17%
The influences of eight metal ions (i.e., Na+, Ca2+, Ag+, Co2+, Cu2+, Al3+, Zn2+, and Mn4+) on mycelia growth and palmarumycins C12 and C13 production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12 were investigated. Three metal ions, Ca2+, Cu2+ and Al3+ were exhibited as the most effective to enhance mycelia growth and palmarumycin production. When calcium ion (Ca2+) was applied to the medium at 10.0 mmol/L on day 3, copper ion (Cu2+) to the medium at 1.0 mmol/L on day 3, aluminum ion (Al3+) to the medium at 2.0 mmol/L on day 6, the maximal yields of palmarumycins C12 plus C13 were obtained as 137.57 mg/L, 146.28 mg/L and 156.77 mg/L, which were 3.94-fold, 4.19-fold and 4.49-fold in comparison with that (34.91 mg/L) of the control, respectively. Al3+ favored palmarumycin C12 production when its concentration was higher than 4 mmol/L. Ca2+ had an improving effect on mycelia growth of Berkleasmium sp. Dzf12. The combination effects of Ca2+, Cu2+ and Al3+ on palmarumycin C13 production were further studied by employing a statistical method based on the central composite design (CCD) and response surface methodology (RSM). By solving the quadratic regression equation between palmarumycin C13 and three metal ions, the optimal concentrations of Ca2+...

A practical synthesis of long-chain iso-fatty acids (iso-C12–C19) and related natural products

Richardson, Mark B; Williams, Spencer J
Fonte: Beilstein-Institut Publicador: Beilstein-Institut
Tipo: Artigo de Revista Científica
Publicado em 04/09/2013 EN
Relevância na Pesquisa
27.17%
A gram-scale synthesis of terminally-branched iso-fatty acids (iso-C12–C19) was developed commencing with methyl undec-10-enoate (methyl undecylenate) (for iso-C12–C14) or the C15 and C16 lactones pentadecanolide (for iso-C15–C17) and hexadecanolide (for iso-C18–C19). Central to the approaches outlined is the two-step construction of the terminal isopropyl group through addition of methylmagnesium bromide to the ester/lactones and selective reduction of the resulting tertiary alcohols. Thus, the C12, C17 and C18 iso-fatty acids were obtained in three steps from commercially-available starting materials, and the remaining C13–C16 and C19 iso-fatty acids were prepared by homologation or recursive dehomologations of these fatty acids or through intercepting appropriate intermediates. Highlighting the synthetic potential of the iso-fatty acids and various intermediates prepared herein, we describe the synthesis of the natural products (S)-2,15-dimethylpalmitic acid, (S)-2-hydroxy-15-methylpalmitic acid, and 2-oxo-14-methylpentadecane.

Vibrational dynamics of a non-degenerate ultrafast rotor: The (C12,C13)-oxalate ion

Kuroda, Daniel G.; Abdo, Mohannad; Chuntonov, Lev; Smith, Amos B.; Hochstrasser, Robin M.
Fonte: AIP Publishing LLC Publicador: AIP Publishing LLC
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.01%
Molecular ions undergoing ultrafast conformational changes on the same time scale of water motions are of significant importance in condensed phase dynamics. However, the characterization of systems with fast molecular motions has proven to be both experimentally and theoretically challenging. Here, we report the vibrational dynamics of the non-degenerate (C12,C13)-oxalate anion, an ultrafast rotor, in aqueous solution. The infrared absorption spectrum of the (C12,C13)-oxalate ion in solution reveals two vibrational transitions separated by approximately 40 cm−1 in the 1500–1600 cm−1 region. These two transitions are assigned to vibrational modes mainly localized in each of the carboxylate asymmetric stretch of the ion. Two-dimensional infrared spectra reveal the presence and growth of cross-peaks between these two transitions which are indicative of coupling and population transfer, respectively. A characteristic time of sub-picosecond cross-peaks growth is observed. Ultrafast pump-probe anisotropy studies reveal essentially the same characteristic time for the dipole reorientation. All the experimental data are well modeled in terms of a system undergoing ultrafast population transfer between localized states. Comparison of the experimental observations with simulations reveal a reasonable agreement...

RedOx Status, Proteasome and APEH: Insights into Anticancer Mechanisms of t10,c12-Conjugated Linoleic Acid Isomer on A375 Melanoma Cells

Bergamo, Paolo; Cocca, Ennio; Palumbo, Rosanna; Gogliettino, Marta; Rossi, Mose; Palmieri, Gianna
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 19/11/2013 EN
Relevância na Pesquisa
27.35%
This study describes the investigation of the efficiency of conjugated linoleic acid (CLA) isomers in reducing cancer cells viability exploring the role of the oxidative stress and acylpeptide hydrolase (APEH)/proteasome mediated pathways on pro-apoptotic activity of the isomer trans10,cis12 (t10,c12)-CLA. The basal activity/expression levels of APEH and proteasome (β-5 subunit) were preliminarily measured in eight cancer cell lines and the functional relationship between these enzymes was clearly demonstrated through their strong positive correlation. t10,c12-CLA efficiently inhibited the activity of APEH and proteasome isoforms in cell-free assays and the negative correlation between cell viability and caspase 3 activity confirmed the pro-apoptotic role of this isomer. Finally, modulatory effects of t10,c12-CLA on cellular redox status (intracellular glutathione, mRNA levels of antioxidant/detoxifying enzymes activated through NF-E2-related factor 2, Nrf2, pathway) and on APEH/β-5 activity/expression levels, were investigated in A375 melanoma cells. Dose- and time-dependent variations of the considered parameters were established and the resulting pro-apoptotic effects were shown to be associated with an alteration of the redox status and a down-regulation of APEH/proteasome pathway. Therefore...

Pseudomonas aeruginosa biofilm-associated homoserine lactone C12 rapidly activates apoptosis in airway epithelia

Schwarzer, Christian; Fu, Zhu; Patanwala, Maria; Hum, Lauren; Lopez-Guzman, Mirielle; Illek, Beate; Kong, Weidong; Lynch, Susan V.; Machen, Terry E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.57%
Pseudomonas aeruginosa (PA) forms biofilms in lungs of cystic fibrosis CF) patients, a process regulated by quorum sensing molecules including N-(3-oxododecanoyl)-L-homoserine lactone, C12. C12 (10–100 μM) rapidly triggered events commonly associated with the intrinsic apoptotic pathway in JME (CFΔF508CFTR, nasal surface) epithelial cells: depolarization of mitochondrial (mito) membrane potential (Δψmito) and release of cytochrome C (cytoC) from mitos into cytosol and activation of caspases 3/7, 8 and 9. C12 also had novel effects on the endoplasmic reticulum (release of both Ca2+ and ER-targeted GFP and oxidized contents into the cytosol). Effects began within 5 minutes and were complete in 1–2 hrs. C12 caused similar activation of caspases and release of cytoC from mitos in Calu-3 (wtCFTR, bronchial gland) cells, showing that C12-triggered responses occurred similarly in different airway epithelial types. C12 had nearly identical effects on three key aspects of the apoptosis response (caspase 3/7, depolarization of Δψmito and reduction of redox potential in the ER) in JME and CFTR-corrected JME cells (adenoviral expression), showing that CFTR was likely not an important regulator of C12-triggered apoptosis in airway epithelia. Exposure of airway cultures to biofilms from PAO1wt caused depolarization of Δψmito and increases in Cacyto like 10–50 μM C12. In contrast...

Potential resonant screening effects on stellar C12+C12 reaction rates

Cussons, R.; Langanke, K.; Liolios, T.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/10/2002
Relevância na Pesquisa
27.35%
The C12+C12 fusion cross sections show resonant behavior down to the lowest energies accessible so far in the laboratory. If this tendency continues into the astrophysical energy range, the stellar C12+C12 reaction rates have to be corrected for resonant screening effects, in addition to the conventional screening corrections. We estimate the resonant screening effects in the weak electron screening limit for hydrostatic burning and white dwarf environments.; Comment: 5 RevTex pages + 1 ps figure. Accepted for publication in Eur.Phys.J.A

Gamma Rays from N15(p, αγ)C12 and N15(p, γ)O16

Kraus, Alfred A., Jr.
Fonte: Instituto de Tecnologia da Califórnia Publicador: Instituto de Tecnologia da Califórnia
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 15/05/1954
Relevância na Pesquisa
27.17%
A new resonance in the reaction N15(p, αγ)C12 giving the 4.43-Mev γ ray from the first excited state of C12 has been found at a proton energy of 1.64±0.03 Mev. The angular distribution of the γ rays indicates that the resonant state in the compound nucleus O16 at an excitation energy of 13.65 Mev has spin and parity equal to 1+ or 2-. The resonance at 1.05-Mev proton energy has been reinvestigated. At this resonance the capture γ rays from the reaction N15(p, γ)O16 are found to be isotropic, which indicates that this 13.09-Mev level of O16 has spin equal to 1. A search was made for capture γ rays at the 0.340-Mev resonance of N15(p, α)C12 but there were less than 1 percent of the number at the 1.05-Mev resonance. Therefore, it seems that these two levels do not have identical spin, parity, and isotopic spin values.