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951.
The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs. 相似文献
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E Pineda-Molina P Klatt J Vázquez A Marina M García de Lacoba D Pérez-Sala S Lamas 《Biochemistry》2001,40(47):14134-14142
The cellular redox status can modify the function of NF-kappaB, whose DNA-binding activity can be inhibited by oxidative, nitrosative, and nonphysiological agents such as diamide, iodoacetamide, or N-ethylmaleimide. This inhibitory effect has been proposed to be mediated by the oxidation of a conserved cysteine in its DNA-binding domain (Cys62) through unknown biochemical mechanisms. The aim of this work was to identify new oxidative modifications in Cys62 involved in the redox regulation of the NF-kappaB subunit p50. To address this problem, we exposed p50, both the native form (p50WT) and its corresponding mutant in Cys62 (C62S), to changes in the redox pair glutathione/glutathione disulfide (GSH/GSSG) ratio ranging from 100 to 0.1, which may correspond to intracellular (patho)physiological states. A ratio between 1 and 0.1 resulted in a 40-70% inhibition of the DNA binding of p50WT, having no effect on the C62S mutant. Mass spectrometry studies, molecular modeling, and incorporation of (3)H-glutathione assays were consistent with an S-glutathionylation of p50WT in Cys62. Maximal incorporation of (3)H-glutathione to the p50WT and C62S was of 0.4 and 0.1 mol of (3)H-GSH/mol of protein, respectively. Because this covalent glutathione incorporation did not show a perfect correlation with the observed inhibition in the DNA-binding activity of p50WT, we searched for other modifications contributing to the maximal inhibition. MALDI-TOF and nanospray-QIT studies revealed the formation of sulfenic acid as an alternative or concomitant oxidative modification of p50. In summary, these data are consistent with new oxidative modifications in p50 that could be involved in redox regulatory mechanisms for NF-kappaB. These postranslational modifications could represent a molecular basis for the coupling of pro-oxidative stimuli to gene expression. 相似文献
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Sergey N. Mikhailov Andrei A. Rodionov Ekaterina V. Efimtseva Boris S. Ermolinsky Marina V. Fomitcheva Nelly Sh. Padyukova 《Nucleosides, nucleotides & nucleic acids》2013,32(4-5):691-692
Abstract The unexpected formation of trisaccharide nucleosides during synthesis of purine 5′-O-β-D-ribofuranosylnucleosides in the presence of Lewis acids was observed. 相似文献
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Richard Spinney Lee Smith Marcella Ucci Abigail Fisher Marina Konstantatou Alexia Sawyer Jane Wardle Alexi Marmot 《PloS one》2015,10(5)
Little is known of the patterns of physical activity, standing and sitting by
office workers. However, insight into these behaviours is of growing interest,
notably in regard to public health priorities to reduce non-communicable disease
risk factors associated with high levels of sitting time and low levels of
physical activity. With the advent and increasing availability of indoor
tracking systems it is now becoming possible to build detailed pictures of the
usage of indoor spaces. This paper reports initial results of indoor tracking
used in conjunction with the ActivPAL activity monitoring device. In this paper
we give an overview of the usage of the tracking system and its installation and
illustrate some of the resultant data. We also provide preliminary results that
investigate the relationship between location, light physical activity and
sitting in a small sample of office workers (n=33) from two separate office
environments in order to demonstrate the relevance and explanatory power of the
technique. 相似文献
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