Search results for "secret"

Bioaccessibility Study of Aflatoxin B1 and Ochratoxin A in Bread Enriched with Fermented Milk Whey and/or Pumpkin

2021

The presence of mycotoxins in cereals and cereal products remains a significant issue. The use of natural ingredients such as pumpkin and whey, which contain bioactive compounds, could be a strategy to reduce the use of conventional chemical preservatives. The aim of the present work was to study the bioaccessibility of aflatoxin B1 (AFB1) and ochratoxin (OTA) in bread, as well as to evaluate the effect of milk whey (with and without lactic acid bacteria fermentation) and pumpkin on reducing mycotoxins bioaccessibility. Different bread typologies were prepared and subjected to an in vitro digestion model. Gastric and intestinal extracts were analyzed by HPLC–MS/qTOF and mycotoxins bio…

Aproximaciones moleculares al estudio de las interacciones de rotavirus y norovirus con el huésped

2020

Los norovirus humanos son los principales agentes etiológicos de gastroenteritis aguda en todo el mundo. Aunque los norovirus son muy diversos (se han detectado más de 30 genotipos en humanos), durante los últimos 40 años la mayoría de los brotes y epidemias han sido causados por cepas del genotipo GII.4, lo que plantea interrogantes sobre su persistencia en la población. Entre otras posibles explicaciones, se considera que la evasión inmunológica es la principal causa de su éxito. Para estudiar en detalle el reconocimiento y la evasión de anticuerpos, analizamos un epítopo conformacional reconocido por un anticuerpo monoclonal (3C3G3) mediante mutagénesis dirigida y resonancia superficial …

The pathophysiology of intestinal lipoprotein production

2015

Intestinal lipoprotein production is a multistep process, essential for the absorption of dietary fats and fat-soluble vitamins. Chylomicron assembly begins in the endoplasmic reticulum with the formation of primordial, phospholipids-rich particles that are then transported to the Golgi for secretion. Several classes of transporters play a role in the selective uptake and/or export of lipids through the villus enterocytes. Once secreted in the lymph stream, triglyceride-rich lipoproteins (TRLs) are metabolized by Lipoprotein lipase (LPL), which catalyzes the hydrolysis of triacylglycerols of very low density lipoproteins (VLDLs) and chylomicrons, thereby delivering free fatty acids to vario…

Focus on the Small GTPase Rab1: A Key Player in the Pathogenesis of Parkinson’s Disease

2021

Parkinson’s disease (PD) is the second most frequent neurodegenerative disease. It is characterized by the loss of dopaminergic neurons in the substantia nigra and the formation of large aggregates in the survival neurons called Lewy bodies, which mainly contain α-synuclein (α-syn). The cause of cell death is not known but could be due to mitochondrial dysfunction, protein homeostasis failure, and alterations in the secretory/endolysosomal/autophagic pathways. Survival nigral neurons overexpress the small GTPase Rab1. This protein is considered a housekeeping Rab that is necessary to support the secretory pathway, the maintenance of the Golgi complex structure, and the regulation of macroau…

Genetic and environmental factors associated with the virulence of fish pathogen Flavobacterium columnare

2016

Deoxycholic Acid Methyl Ester — a Novel Bacterial Metabolite of Cholic Acid

1985

Summary Methyl deoxycholate was identified as a novel bacterial metabolite of cholate, produced anaerobically by strains of most saccharolytic Bacteroides species ( B. distasonis, B. eggerthii, B. fragilis, B. incommunis, B. thetaiotaomicron, B. uniformis, B. variabilis, B. vulgatus , and unnamed species). It was also detected with a few strains of Eubacterium and Lactobacillus species. Among 2476 freshly isolated human fecal cultures the frequency of carboxyl group esterification was comparable with that of 7α-dehydroxylation (92 versus 102 cultures). Both activities were, however, lost for unknown reasons after serial transfers. Two of ten mixed fecal cultures tested esterified 3α,7α- or …

The effect of amphiphilic compounds on the secretion of levansucrase by Zymomonas mobilis

2005

Abstract The effect of some aliphatic (n-butanol to n-hexadecanol) and aromatic (benzyl and phenethyl alcohols), anesthetics (procaine) and surfactants (Tween 20 to Tween 80) on the secretion of levansucrase by the levan-producing strain of Gram-negative ethanologenic bacteria Zymomonas mobilis 113S were examined in this study. During incubation of Z. mobilis cells with sucrose (10 mM) a decrease of the levansucrase activity was observed in the presence of these amphiphilic compounds concomitantly with an increase of a total amount of protein in the medium. Since none of the compounds under study had any effect on enzyme activity in vitro observed structure- and concentration-dependent rela…

Alpha-secretase activation--an approach to Alzheimer's disease therapy.

2006

The nonamyloidogenic pathway of processing the amyloid precursor protein (APP) involves the cleavage within the amyloid-beta peptide sequence, and thus precludes amyloid-beta formation. The identification of a member of the disintegrin and metalloproteinase family, ADAM10, as an alpha-secretase that prevents plaque formation and hippocampal deficits in vivo gave us the possibility to examine the alpha-secretase as a potential target for the therapy of Alzheimer's disease. Within the priority program Cellular Mechanisms of Alzheimer's Disease, we investigated several approaches to stimulate the alpha-secretase pathway. Two protein convertases were found to be responsible for the removal of t…

The Role of the anti-amyloidogenic secretase ADAM10 in shedding the APP-like proteins.

2011

ADAM10 (A disintegrin and metalloproteinase 10) has been demonstrated as an enzyme with protective properties in Alzheimer's disease: in mouse models it not only lowered generation of toxic A-beta peptides and formation of senile plaques but also alleviated learning deficits and enhanced synaptic density. This is due to cleavage of the amyloid precursor protein (APP) within its A-beta stretch and to the release of the extracellular domain of APP with neuroprotective function. Aside from cleaving APP, ADAM10 has been linked to over 40 putative substrates at least in cell culture. These substrates are connected with important cellular functions such as cell migration, stress response and tran…

The Non-Amyloidogenic Pathway: Structure and Function of α-Secretases

2006

The amyloid cascade hypothesis is the most accepted explanation for the pathogenesis of Alzheimer’s disease (AD). APP is the precursor of the amyloid β peptide (Aβ), the principal proteinaceous component of amyloid plaques in brains of Alzheimer’s disease patients. Proteolytic cleavage of APP by the α-secretase within the Aβ sequence precludes formation of amyloidogenic peptides and leads to a release of soluble APPsα which has neuroprotective properties. In several studies, a decreased amount of APPsα in the cerebrospinal fluid of AD patients has been observed. Three members of the ADAM family (a disintegrin and metalloproteinase) ADAM-10, ADAM-17 (TACE) and ADAM-9 have been proposed as α-…