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Fatty acid profile and qualitative characteristics of meat from zebu steers fed with different oilseeds

OLIVEIRA, D. M.; LADEIRA, M. M.; CHIZZOTTI, M. L.; MACHADO NETO, O. R.; RAMOS, E. M.; GONCALVES, T. M.; BASSI, M. S.; LANNA, D. P. D.; RIBEIRO, J. S.
Fonte: AMER SOC ANIMAL SCIENCE Publicador: AMER SOC ANIMAL SCIENCE
Tipo: Artigo de Revista Científica
ENG
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The objective of this study was to evaluate the effects of dietary addition of ground oilseed sources on the quality, fatty acid profile, and CLA content of meat from zebu steers. Thirty-one zebu steers with an initial average age of 23 mo and an initial BW of 365 kg were used in this study. The experimental period was 84 d, which was preceded by an adaption period of 28 d. The diet was provided ad libitum with a forage: concentrate ratio of 40:60. Corn silage was used as the forage source. Four different concentrates were formulated for each treatment: without additional lipids (control) or with ground soybeans (SB), ground cottonseed (CS), or ground linseed (LS). The SB, CS, and LS diets were formulated to have 6.5% ether extract on a total dietary DM basis. The experiment was set up as a completely randomized design. After slaughter, samples were taken from the longissimus thoracis muscle for the measurement of fatty acid concentration and the evaluation of meat quality. The luminosity index was greater in the control and LS diets (P < 0.01). The greatest percentages of myristic acid (C14:0), palmitic acid (C16:0), trans octadecenoic acid (C18:1 trans-10, trans-11, or trans-12), and SFA in the subcutaneous fat were observed in the CS treatment (P < 0.01). Moreover...

Ascorbic acid concentration is reduced in the secondary aqueous humour of glaucomatous patients

LEITE, Mauro T.; PRATA, Tiago S.; KERA, Clarissa Z.; MIRANDA, Denise V.; BARROS, Silvia B. de Moraes; MELO JR., Luiz A. S.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
45.44%
P>Background: We aimed to evaluate the ascorbic acid concentration in secondary aqueous humour (AH) from glaucomatous patients and to compare it with primary AH from primary open-angle glaucoma patients and non-glaucomatous patients. Methods: Primary AH samples were prospectively obtained from clinically uncontrolled primary open-angle glaucoma patients and senile cataract patients (controls) prior to trabeculectomy and cataract surgery. Secondary AH samples were obtained from eyes with previous intraocular surgery, prior to trabeculectomy or cataract surgery. AH (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber just before surgery and then immediately stored at -80 degrees C. The ascorbic acid concentration was determined in a masked fashion by high-pressure liquid chromatography. Results: A total of 18 patients with senile cataract, 16 glaucomatous patients with primary AH (no previous intraocular surgery) and 11 glaucomatous patients with secondary AH (previous intraocular surgery) were included. There was no difference in mean age between groups (P = 0.15). The mean +/- standard deviation concentration of ascorbic acid in the secondary AH from glaucomatous patients (504 +/- 213 mu mol/L [95% confidence interval {CI}...

Use of multiple channel pH monitoring for evaluation of ultra-distal reflux in patients after fundoplication for treatment of Barrett`s esophagus

SEGURO, F. C. B. C.; SANTO, M. A.; SZACHNOWICZ, S.; MALUF FILHO, F.; KISHI, H. S.; FALCAO, A. M.; NASI, A.; SALLUM, R. A. A.; CECCONELLO, I.
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
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Dysplasia and esophageal adenocarcinoma may arise in patients with Barrett`s esophagus after fundoplication esophageal pH monitoring showing no acid in esophagus. This suggests the need to develop methodology to evaluate the occurrence of ultra-distal reflux (1 cm above the LES). The objective of the study was to compare acid exposition in three different levels: 5 cm above the upper border of the LES, 1 cm above the LES and in the intrasphincteric region. Eleven patients with Barrett`s esophagus after Nissen fundoplication with no clinical, endoscopic and radiologic evidence of reflux were selected. Four-channel pH monitoring took place: channel A, 5 cm above the upper border of the LES; channel B, 1 cm above the LES; channel C, intrasphincteric; channel D, intragastric. The results of channels A, B and C were compared. There was significant increase in number of reflux episodes and a higher fraction of time with pH <4.0 in channel B compared to channel A. There was significant decrease in fraction of time with pH <4.0 in channel B compared to channel C. Two cases of esophageal adenocarcinoma were diagnosed in the studied patients. The region 1 cm above the upper border of the LES is more exposed to acid than the region 5 cm above the upper border of the LES...

In vitro uptake and antimycobacterial activity of liposomal usnic acid formulation

LIRA, Mariane C. B.; SIQUEIRA-MOURA, Marigilson P.; ROLIM-SANTOS, Hercilia M. L.; GALETTI, Fabio C. S.; SIMIONI, Andreza R.; SANTOS, Noemia P.; EGITO, Eryvaldo S. Tabosa Do; SILVA, Celio L.; TEDESCO, Antonio C.; SANTOS-MAGALHAES, Nereide S.
Fonte: TAYLOR & FRANCIS INC Publicador: TAYLOR & FRANCIS INC
Tipo: Artigo de Revista Científica
ENG
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45.45%
The cellular uptake and antimycobacterial activity of usnic acid (UA) and usnic acid-loaded liposomes (UA-LIPOs) were assessed on J774 macrophages. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of UA and UA-LIPO against Mycobacterium tuberculosis were determined. Concentrations required to inhibit 50% of cell proliferation (IC(50)) were 22.5 (+/- 0.60) and 12.5 (+/- 0.26) mu g/ml, for UA and UA-LIPO, respectively. The MICs of UA and UA-LIPO were 6.5 and 5.8 mu g/mL, respectively. The MBC of UA-LIPO was twice as low (16 mu g/mL) as that of UA (32 mu g/mL). An improvement in the intracellular uptake of UA-LIPO was found (21.6 x 10(4) +/- 28.3 x 10(2) c.p.s), in comparison with UA (9.5 x 10(4) +/- 11.4 x 10(2) c.p.s). In addition, UA-LIPO remains much longer inside macrophages (30 hours). All data obtained from the encapsulation of usnic acid into liposomes as a drug delivery system (DDS) indicate a strong interaction between UA-liposomes and J774 macrophages, thereby facilitating UA penetration into cells. Considering such a process as ruling the Mycobacterium-transfection by magrophages, we could state that associating UA with this DDS leads to an improvement in its antimycobacterial activity.; Brazilian Ministry of Education (CAPES); Brazilian Council for Scientific and Technological Development (CNPq)[334946-01]; Brazilian Council for Scientific and Technological Development (CNPq)[141585/2004-08]; Brazilian Network Research on Nanobiotechnology-Nanobiotec CNPq/MCT

Thiol and Sulfenic Acid Oxidation of AhpE, the One-Cysteine Peroxiredoxin from Mycobacterium tuberculosis: Kinetics, Acidity Constants, and Conformational Dynamics

HUGO, Martin; TURELL, Lucia; MANTA, Bruno; BOTTI, Horacio; MONTEIRO, Gisele; NETTO, Luis E. S.; ALVAREZ, Beatriz; RADI, Rafael; TRUJILLO, Madia
Fonte: AMER CHEMICAL SOC Publicador: AMER CHEMICAL SOC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Drug resistance and virulence of Mycobacterium tuberculosis are partially related to the pathogen`s antioxidant systems. Peroxide detoxification in this bacterium is achieved by the heme-containing catalase peroxidase and different two-cysteine peroxiredoxins. M. tuberculosis genome also codifies for a putative one-cysteine peroxiredoxin, alkyl hydroperoxide reductase E (MtAhpE). Its expression was previously demonstrated at a transcriptional level, and the crystallographic structure of the recombinant protein was resolved under reduced and oxidized states. Herein, we report that the conformation of MtAhpE changed depending on its single cysteine redox state, as reflected by different tryptophan fluorescence properties and changes in quaternary structure. Dynamics of fluorescence changes, complemented by competition kinetic assays, were used to perform protein functional studies. MtAhE reduced peroxynitrite 2 orders of magnitude faster than hydrogen peroxide (1.9 x 10(7) M(-1) s(-1) vs 8.2 x 10(4) M(-1) s(-1) at pH 7.4 and 25 degrees C, respectively). The latter also caused cysteine overoxidation to sulfinic acid, but at much slower rate constant (40 M(-1) s(-1)). The pK(a) of the thiol in the reduced enzyme was 5.2, more than one unit lower than that of the sulfenic acid in the oxidized enzyme. The pH profile of hydrogen peroxide-mediated thiol and sulfenic acid oxidations indicated thiolate and sulfenate as the reacting species. The formation of sulfenic acid as well as the catalytic peroxidase activity of MtAhpE was demonstrated using the artificial reducing substrate thionitrobenzoate. Taken together...

Antibacterial and antiparasitic effects of Bothrops marajoensis venom and its fractions: Phospholipase A(2) and L-amino acid oxidase

Costa Torres, Alba Fabiola; Dantas, Rodrigo Tavares; Toyama, Marcos H.; Diz Filho, Eduardo; Zara, Fernando Jose; Rodrigues de Queiroz, Maria Goretti; Pinto Nogueira, Nadia Accioly; de Oliveira, Marcia Rosa; Toyama, Daniela de Oliveira; Monteiro, Helena S.
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 795-804
ENG
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45.46%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Some proteins present in snake venom possess enzymatic activities, such as phospholipase A(2) and L-amino acid oxidase. In this study, we verify the action of the Bothrops marajoensis venom (BmarTV), PLA(2) (BmarPLA(2)) and LAAO (BmarLAAO) on strains of bacteria, yeast, and Leishmania sp. The BmarTV was isolated by Protein Pack 5PW, and several fractions were obtained. Reverse phase HPLC showed that BmarPLA(2) was isolated from the venom, and N-terminal amino acid sequencing of sPLA(2) showed high amino acid identity with other lysine K49 sPLA(2)s isolated from Bothrops snakes. The BmarLAAO was purified to high molecular homogeneity and its N-terminal amino acid sequence demonstrated a high degree of amino acid conservation with others LAAOs. BmarLAAO was able to inhibit the growth of P. aeruginosa, C. albicans and S. aureus in a dose-dependent manner. The inhibitory effect was more significant on S. aureus, with a MIC = 50 mu g/mL and MLC = 200 mu g/mL However, the BmarTV and BmarPLA(2) did not demonstrate inhibitory capacity. BmarLAAO was able to inhibit the growth of promastigote forms of L chagasi and L amazonensis, with an IC50 = 2.55 mu g/mL and 2.86 mu g/mL for L. amazonensis and L. chagasi...

Conjugated linoleic acid and cardiac health: Oxidative stress and energetic metabolism in standard and sucrose-rich diets

Diniz, Yeda S.; Santos, Priscila P.; Assalin, Heloisa B.; Souza, Gisele A.; Rocha, Katiucha K. H. R.; Ebaid, Geovana Xavier; Seiva, Fabio R. F.; Amauchi, Juliana F.; Novelli Filho, Jose Luiz V. B.; Novelli, Ethel L. B.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 318-325
ENG
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Studies on conjugated linoleic acid ingestion and its effect on cardiac tissue are necessary for the safe utilization of this compound as supplement for weight loss. Male Wistar 24-rats were divided into four groups (n = 6):(C)given standard chow, water and 0.5 ml saline, twice a week by gavage; (C-CLA)receiving standard chow, water and 0.5 ml of conjugated linoleic acid, twice a week, by gavage; (S)given standard chow, saline by gavage, and 30% sucrose in its drinking water; (S-CLA)receiving standard chow, 30% sucrose in its drinking water and conjugated linoleic acid. After 42 days of treatment S rats had obesity with increased abdominal-circumference, dyslipidemia, oxidative stress and myocardial lower citrate synthase(CS) and higher lactate dehydrogenase(LDH) activities than C. Conjugated linoleic acid had no effects on morphometric parameters in C-CLA, as compared to C, but normalized morphometric parameters comparing S-CLA with S. There was a negative correlation between abdominal adiposity and resting metabolic rate. Conjugated linoleic acid effect, enhancing fasting-VO2/surface area, postprandial-carbohydrate oxidation and serum lipid hydroperoxide resembled to that of the S group. Conjugated linoleic acid induced cardiac oxidative stress in both fed conditions...

Arabidopsis Mutants Resistant to S(+)-β-Methyl-α, β-Diaminopropionic Acid, a Cycad-Derived Glutamate Receptor Agonist1

Brenner, Eric D.; Martinez-Barboza, Nora; Clark, Alexandra P.; Liang, Quail S.; Stevenson, Dennis W.; Coruzzi, Gloria M.
Fonte: American Society of Plant Physiologists Publicador: American Society of Plant Physiologists
Tipo: Artigo de Revista Científica
Publicado em /12/2000 EN
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Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that are the predominant neuroreceptors in the mammalian brain. Genes with high sequence similarity to animal iGluRs have been identified in Arabidopsis. To understand the role of Arabidopsis glutamate receptor-like (AtGLR) genes in plants, we have taken a pharmacological approach by examining the effects of BMAA [S(+)-β-methyl-α, β-diaminopropionic acid], a cycad-derived iGluR agonist, on Arabidopsis morphogenesis. When applied to Arabidopsis seedlings, BMAA caused a 2- to 3-fold increase in hypocotyl elongation and inhibited cotyledon opening during early seedling development. The effect of BMAA on hypocotyl elongation is light specific. Furthermore, BMAA effects on early morphogenesis of Arabidopsis can be reversed by the simultaneous application of glutamate, the native iGluR agonist in animals. To determine the targets of BMAA action in Arabidopsis, a genetic screen was devised to isolate Arabidopsis mutants with a BMAA insensitive morphology (bim). When grown in the light on BMAA, bim mutants exhibited short hypocotyls compared with wild type. bim mutants were grouped into three classes based on their morphology when grown in the dark in the absence of BMAA. Class-I bim mutants have a normal...

Effects of Phosfon-S on Nucleic Acid Metabolism in Pisum sativum Alaska

Brook, Judith; West, S. H.; Anthony, D. S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1967 EN
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Phosfon-S, a substance which inhibits stem elongation, alters nucleic acid metabolism in Pisum sativum Alaska. Methylated albumin kieselguhr (MAK) columns were used to fractionate 32P-labeled nucleic acids. Phosfon-S treatment of the plants resulted in a decrease in soluble RNA and an increase in ribosomal RNA. Specific activities of the various nucleic acid fractions were lower as a result of treatment. The nucleic acids from treated tissues were more resistant to RNase degradation, and endogenous RNase activity was lower in treated tissues. When RNase treated nucleic acids were fractionated on MAK columns, the DNA-RNA fractions from treated plants had a higher specific activity than that of the control, which was not true before nuclease treatment. Spectrophotometric examination of this fraction revealed a difference in absorption spectra, possibly indicating a Phosfon-S nucleic acid complex. It is suggested that these alterations in nucleic acid metabolism could in turn alter a wide variety of metabolic processes, resulting in retarded growth.

Cloning and sequencing of the medium-chain S-acyl fatty acid synthetase thioester hydrolase cDNA from rat mammary gland.

Naggert, J; Williams, B; Cashman, D P; Smith, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/04/1987 EN
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cDNA clones coding for the medium-chain S-acyl fatty acid synthetase thioester hydrolase (thioesterase II) from rat mammary gland were identified in a bacteriophage lambda gt11 library and their nucleotide sequences were determined. The predicted coding region spans 263 amino acid residues and includes a sequence identical with that of a peptide derived from the enzyme active site. The rat thioesterase II cDNA sequence exhibits homology with that of a thioesterase found in duck uropygial glands.

Enantioselective Metabolism of Chiral 3-Phenylbutyric Acid, an Intermediate of Linear Alkylbenzene Degradation, by Rhodococcus rhodochrous PB1

Simoni, S.; Klinke, S.; Zipper, C.; Angst, W.; Kohler, H. E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1996 EN
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Rhodococcus rhodochrous PB1 was isolated from compost soil by selective culture with racemic 3-phenylbutyric acid as the sole carbon and energy source. Growth experiments with the single pure enantiomers as well as with the racemate showed that only one of the two enantiomers, (R)-3-phenylbutyric acid, supported growth of strain PB1. Nevertheless, (S)-3-phenylbutyric acid was cometabolically transformed to, presumably, (S)-3-(2,3-dihydroxyphenyl)butyric acid (the absolute configuration at the C-3 atom is not known yet) by (R)-3-phenylbutyric acid-grown cells of strain PB1, as shown by (sup1)H nuclear magnetic resonance spectroscopy of the partially purified compound and gas chromatography-mass spectrometry analysis of the trimethylsilyl derivative. Oxygen uptake rates suggest that either 3-phenylpropionic acid or cinnamic acid (trans-3-phenyl-2-propenoic acid) is the substrate for aromatic ring hydroxylation. This view is substantiated by the fact that 3-(2,3-dihydroxyphenyl)propionic acid was a substrate for meta cleavage in cell extracts of (R)-3-phenylbutyric acid-grown cells of strain PB1. Gas chromatography-mass spectrometry analysis of trimethylsilane-treated ethyl acetate extracts of incubation mixtures showed that both the meta-cleavage product...

Segmentation induced by intraluminal fatty acid in isolated guinea-pig duodenum and jejunum

Gwynne, Rachel M; Thomas, E A; Goh, S M; Sjövall, H; Bornstein, J C
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
EN
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Small intestinal movements depend on the composition of the chyme with mixing predominating at high nutrient levels and propulsion being prevalent at low nutrient levels. The mechanisms coupling nutrients to motility are unknown. We used computer analysis of video recordings of isolated guinea-pig duodenum, jejunum and ileum to examine movements induced by a fatty acid, decanoic acid. Increasing intraluminal pressure past a threshold using control saline consistently evoked propulsive reflexes: lumen-occluding constrictions appeared at the oral end propagating at 20.4 ± 2.4 mm s−1 (mean ±s.d., jejunum) to the anal end before being repeated until the intraluminal pressure was returned to control. Subthreshold pressure increases sometimes evoked a transient series of constrictions appearing at the oral end and propagating anally at 18.4 ± 4.7 mm s−1 (jejunum). At basal pressures, decanoic acid dose-dependently induced motor activity consisting of 40–60 s episodes of constrictions separated by 40–200 s periods of quiescence and lasting up to 2 h. Five contraction patterns were identified within episodes including localized stationary constrictions; constrictions that propagated slowly (5–8 mm s−1) for short distances orally or anally; and constrictions that propagated orally or anally for the length of the preparation at 14–20 mm s−1. Decanoic acid induced motor activity was reversibly abolished by tetrodotoxin (3 μm)...

Synthesis of β-(S-methyl)thioaspartic acid and derivatives

Heredia-Moya, Jorge; Kirk, Kenneth L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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β-(S-Methyl)thioaspartic acid occurs as a posttranslational modification at position 88 in E. coli ribosomal protein S12, a position that is a mutational hotspot resulting in both antibiotic-resistant and antibiotic-sensitive phenotypes. Critical to research designed to determine the biological function of β-(S-methyl)thioaspartic acid will be the availability of synthetic β-(S-methyl)thioaspartic acid as well as derivatives designed for peptide incorporation. We report here the synthesis of β-(S-methyl)thioaspartic acid and derivatives. The installation of the β-methylthio moiety into the aspartic acid structure was accomplished by electrophilic sulfenylation of N-protected-L-aspartic acid derivatives with 2,4-dinitrophenyl methyl disulfide. Following this key transformation, we were able to prepare protected β-(S-methyl)thioaspartic acid derivative suitable for peptide coupling.

Insulin is required for amino acid stimulation of dual pathways for translational control in skeletal muscle in the late-gestation ovine fetus

Brown, Laura D.; Rozance, Paul J.; Barry, James S.; Friedman, Jacob E.; Hay, William W.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
EN
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45.45%
During late gestation, amino acids and insulin promote skeletal muscle protein synthesis. However, the independent effects of amino acids and insulin on the regulation of mRNA translation initiation in the fetus are relatively unknown. The purpose of this study was to determine whether acute amino acid infusion in the late-gestation ovine fetus, with and without a simultaneous increase in fetal insulin concentration, activates translation initiation pathway(s) in skeletal muscle. Fetuses received saline (C), mixed amino acid infusion plus somatostatin infusion to suppress amino acid-stimulated fetal insulin secretion (AA+S), mixed amino acid infusion with concomitant physiological increase in fetal insulin (AA), or high-dose insulin infusion with euglycemia and euaminoacidemia (HI). After a 2-h infusion period, fetal skeletal muscle was harvested under in vivo steady-state conditions and frozen for quantification of proteins both upstream and downstream of mammalian target of rapamycin (mTOR). In the AA group, we found a threefold increase in ribosomal protein S6 kinase (p70S6k) and Erk1/2 phosphorylation; however, blocking the physiological rise in insulin with somatostatin in the AA+S group prevented this increase. In the HI group...

Uso de antioxidantes para a eleva??o da qualidade do s?men criopreservado de b?falos (Bubalus bubalis)

CASTRO, S?mia Rubielle Silva de
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Dissertação de Mestrado
POR
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45.48%
O s?men bubalino sofre com o processo de congela??o que leva ao estresse oxidativo. O objetivo do trabalho foi desenvolver mecanismo de C de s?men, com adi??o de subst?ncias antioxidantes, que permita reduzir a mortalidade esperm?tica e as inj?rias celulares, a fim de aumentar a potencial fertilidade do s?men bubalino p?s-descongela??o. Foram utilizados 5 touros bubalinos da ra?a Murrah (4-8 anos). As coletas de s?men foram realizadas pelo m?todo de ?vagina artificial. Os ejaculados foram aliquotados para congela??o, configurando quatro tratamentos distintos: Grupo Controle - congela??o com diluidor TESTRIS; Grupo Vitamina C - TES-TRIS associado ? vitamina C (2,5 mM); Grupo Pentoxifilina - TES-TRIS com pentoxifilina (3,5 mM); e Grupo Vitamina C + Pentoxifilina - TES-TRIS com vitamina C (2,5 mM) e pentoxifilina (3,5 mM). Foram analisadas no s?men in natura (Fase Pr?-Congela??o) o volume, pH, cor, aspecto, turbilhonamento, concentra??o do ejaculado, motilidade progressiva, vigor, integridade de membrana plasm?tica e morfologia esperm?tica. Ap?s os processos de congela??o-descongela??o (Fase P?s-Descongela??o) e ap?s o teste de termo-resist?ncia (Fase P?s-TTR), as an?lises de motilidade, vigor, integridade de membrana plasm?tica e morfologia esperm?tica foram realizadas. Os resultados foram analisados por ANOVA...

Coberturas ?? base de quitosana na qualidade p??s-colheita de morangos cv. Aromas .; Chitosan based coating on post-harvest quality of strawberry cv. Aromas.

COSTA, Cristina Sim??es da
Fonte: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Ci??ncia e Tecnologia Agroindustrial; UFPel; BR Publicador: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Ci??ncia e Tecnologia Agroindustrial; UFPel; BR
Tipo: Tese de Doutorado Formato: application/pdf
POR
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45.49%
Strawberry is a highly perishable fruit, presenting a post-harvest shelf life relatively short due to physiologic changes and incidence of fungal decay, which limitate its fresh commercialization. Chitosan based edible coating are a good alternative on controlling post harvest changes associated do strawberry decay. This work was divided in two experiments. In first article, the application of chitosan edible coatings added of calcium and fat acid to promote preservation of the quality of strawberry cv. Aromas during refrigerated storage. Three coatings were studied: chitosan + calcium chloridre (QC), . chitosan + calcium chloride + oleic acid (QCAO), and chitosan + calcium chloride + stearic acid (QCAE). After coatings were applied, the fruits were stored at + 2??C e 75 ?? 5%HR for 10 days. Firmness, pH, titratable acidity, content of soluble solids and, color weren t affected significantly at the end of storage, and no differences between treatment were observed. Coating affected significantly fungal decay on QC coated fruits when compared to non coated fruits, promoting 83%. Fruits that received QC or QCAE coating obtained same acceptability of control fruits. In the second article, the ability of chitosan edible coating, added of calcium and/or ascorbic acid to maintain strawberry post-harvest quality under refrigerated (0??C) and atmospheric (25??C) storage was evaluated. Four coatings were studied: chitosan (Q); chitosan + calcium chloridre (QC)...

Efeito dos tratamentos alcalino, ??cido e oxidativo nas propriedades de amido de milho; Efeito dos tratamentos alcalino, ??cido e oxidativo nas propriedades de amido de milho; Effect of alkali, acid and oxidative treatments on the properties of corn starch; Effect of alkali, acid and oxidative treatments on the properties of corn starch

SPIER, Franciela
Fonte: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Ci??ncia e Tecnologia Agroindustrial; UFPel; BR Publicador: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Ci??ncia e Tecnologia Agroindustrial; UFPel; BR
Tipo: Dissertação Formato: application/pdf
POR
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45.47%
The starch market has been growing and improving, leading to search for products with unique functional properties that industry requirements. The use of native starches is limited, depending on the processing conditions such as temperature, pH, pressure restricting its application in industrial scale. The production of modified starch is an alternative that has been in development for some time in order to overcome one or more limitations of native starches, increasing its use in industry. The objective of this research was to evaluate the properties of corn starch chemically modified, alone or combined action by the acid, oxidative and alkaline. The corn starch granules were treated with a solution of sodium hydroxide at concentrations of 0.09% and 0.18%, with lactic acid solution, 2% and 4%, and a solution of sodium hypochlorite 1% and 2%. Later were neutralized, washed, dried, ground and stored. The starches were evaluated for amylose content, content of carbonyl and carboxyl, paste properties, diffraction of X-ray, swelling power and solubility and enzymatic susceptibility. The corn starch oxidized with sodium hypochlorite (2%) showed a reduction in levels of amylose and treated with alkali and acid increased. The oxidative treatment increased gradually...

Biostructural and pharmacological studies of bicyclic analogues of the 3-isoxazolol glutamate receptor agonist ibotenic acid

Frydenvang, K.; Pickering, D.S.; Greenwood, J.R.; Krogsgaard-Larsen, N.; Brehm, L.; Nielsen, B.; Vogensen, S.B.; Hald, H.; Kastrup, J.S.; Krogsgaard-Larsen, P.; Clausen, R.P.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
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We describe an improved synthesis and detailed pharmacological characterization of the conformationally restricted analogue of the naturally occurring nonselective glutamate receptor agonist ibotenic acid (RS)-3-hydroxy-4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-7-carboxylic acid (7-HPCA, 5) at AMPA receptor subtypes. Compound 5 was shown to be a subtype-discriminating agonist at AMPA receptors with higher binding affinity and functional potency at GluA1/2 compared to GluA3/4, unlike the isomeric analogue (RS)-3-hydroxy-4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-5-carboxylic acid (5-HPCA, 4) that binds to all AMPA receptor subtypes with comparable potency. Biostructural X-ray crystallographic studies of 4 and 5 reveal different binding modes of (R)-4 and (S)-5 in the GluA2 agonist binding domain. WaterMap analysis of the GluA2 and GluA4 binding pockets with (R)-4 and (S)-5 suggests that the energy of hydration sites is ligand dependent, which may explain the observed selectivity.; Karla Frydenvang, Darryl S. Pickering, Jeremy R. Greenwood, Niels Krogsgaard-Larsen, Lotte Brehm, Birgitte Nielsen, Stine B. Vogensen, Helle Hald, Jette S. Kastrup, Povl Krogsgaard-Larsen, and Rasmus P. Clausen

Hypobromous acid, a powerful endogenous electrophile: Experimental and theoretical studies

Ximenes, Valdecir Farias; Morgon, Nelson Henrique; Souza, Aguinaldo Robinson de
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 61-68
ENG
Relevância na Pesquisa
45.47%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Hypobromous acid (HOBr) is an inorganic acid produced by the oxidation of the bromide anion (Br-). The blood plasma level of Br- is more than 1,000-fold lower than that of chloride anion (Cl-). Consequently, the endogenous production of HOBr is also lower compared to hypochlorous acid (HOCl). Nevertheless, there is much evidence of the deleterious effects of HOBr. From these data, we hypothesized that the reactivity of HOBr could be better associated with its electrophilic strength. Our hypothesis was confirmed, since HOBr was significantly more reactive than HOCl when the oxidability of the studied compounds was not relevant. For instance: anisole (HOBr, k(2) = 2.3 x 10(2) M-1 s(-1), HOCl non-reactive); dansylglycine (HOBr, k(2) = 7.3 x 10(6) M-1 s(-1), HOCl, 5.2 x 10(2) M-1 s(-1)); salicylic acid (HOBr, k(2) = 4.0 x 10(4) M-1 s(-1), non-reactive); 3-hydroxybenzoic acid (HOBr, k(2) = 5.9 x 10(4) M-1 s(-1), HOCl, k(2) = 1.1 x 10(1) M-1 s(-1)); uridine (HOBr, k(2) = 13 x 10(3) M-1 s(-1), HOCl non-reactive). The compounds 4-bromoanisole and 5-bromouridine were identified as the products of the reactions between HOBr and anisole or uridine...

α-Synuclein occurs in lipid-rich high molecular weight complexes, binds fatty acids, and shows homology to the fatty acid-binding proteins

Sharon, Ronit; Goldberg, Matthew S.; Bar-Josef, Ifat; Betensky, Rebecca A.; Shen, Jie; Selkoe, Dennis J.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 31/07/2001 EN
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α-Synuclein (αS) is a 140-residue neuronal protein that forms insoluble cytoplasmic aggregates in Parkinson's disease (PD) and several other neurodegenerative disorders. Two missense mutations (A53T and A30P) are linked to rare forms of familial PD. The normal function of αS is unknown, and cultured cell systems that model its modification from soluble monomers to aggregated forms have not been reported. Through a systematic centrifugal fractionation of mesencephalic neuronal cell lines and transgenic mouse brains expressing wild-type or A53T human αS, we observed unusual, previously unrecognized species of αS that migrate well above the 17-kDa monomeric form in denaturing gels. Incubation at 65°C of high-speed cytosols from cells or brains revealed a modified αS species migrating at ≈36 kDa and an extensive higher molecular mass αS-reactive smear. Extraction of the cytosols with chloroform/methanol or with a resin (Lipidex 1000) that binds fatty acids resulted in a similar pattern of higher molecular mass αS forms. On the basis of this effect of delipidation, we reexamined the primary structure of αS and detected a motif at the N and C termini that is homologous to a fatty acid-binding protein signature. In accord, we found that purified human αS binds oleic acid...