Search results for "Peptides"

Effect of high pressure on the antimicrobial activity and secondary structure of the bacteriocin nisin

2018

International audience; Effect of high pressure (HP) treatment on the antimicrobial properties and the structure of nisin was evaluated. Nisin solutions at pH 2.8 or 6.1 were treated by HP at 500 MPa – 10 min – 20 °C and their antimicrobial potency was determined. It appeared that HP clearly impacted the antimicrobial activity of nisin, with respective activity loss of 22.5% and 49.9% at pH 2.8 and 6.1. Structural analysis of nisin by circular dichroism and Fourier transform-infrared spectroscopies revealed that the decrease of nisin antimicrobial activity was likely due to the unfolding of the protein induced by HP. A loss of nisin β-turns structure, particularly significant at neutral pH,…

Vascular pathology: Cause or effect in Alzheimer disease?

2018

Introduction: Alzheimer disease (AD) is the main cortical neurodegenerative disease. The incidence of this disease increases with age, causing significant medical, social and economic problems, especially in countries with ageing populations. Objective: This review aims to highlight existing evidence of how vascular dysfunction may contribute to cognitive impairment in AD, as well as the therapeutic possibilities that might arise from this evidence. Development: The vascular hypothesis emerged as an alternative to the amyloid cascade hypothesis as an explanation for the pathophysiology of AD. This hypothesis locates blood vessels as the origin for a variety of pathogenic pathways that lead …

Optimal doses of caspofungin during continuous venovenous hemodiafiltration in critically ill patients

2017

Production of High Amounts of Hepatotoxin Nodularin and New Protease Inhibitors Pseudospumigins by the Brazilian Benthic Nostoc sp. CENA543

2017

Nostoc is a cyanobacterial genus, common in soils and a prolific producer of natural products. This research project aimed to explore and characterize Brazilian cyanobacteria for new bioactive compounds. Here we report the production of hepatotoxins and new protease inhibitors from benthic Nostoc sp. CENA543 isolated from a small, shallow, saline-alkaline lake in the Nhecolandia, Pantanal wetland area in Brazil. Nostoc sp. CENA543 produces exceptionally high amounts of nodularin-R. This is the first free-living Nostoc that produces nodularin at comparable levels as the toxic, bloom-forming, Nodularia spumigena. We also characterized pseudospumigins A-F, which are a novel family of linear te…

Marinomonas spartinae sp. nov., a novel species with plant-beneficial properties.

2016

Two strains of Gram-stain-negative, chemo-organotrophic, aerobic and halophilic gammaproteobacteria, isolated from within the stem and roots of Spartina maritima in salt marshes from the south Atlantic Spanish coast, were found to represent a novel species in the genus Marinomonas through phylogenetic analysis of their 16S rRNA genes and phenotypic characterization. 16S rRNA gene sequences of the two strains shared < 96.2 % similarity with other Marinomonas species, with Marimonas alcarazii being the most similar in sequence. They required sodium ions for growth, were able to thrive at low (4 °C) temperatures and at salinities of 12–15 %, were unable to hydrolyse any tested macromolecule ex…

Loss-of-Function Mutations in UNC45A Cause a Syndrome Associating Cholestasis, Diarrhea, Impaired Hearing, and Bone Fragility

2018

International audience; Despite the rapid discovery of genes for rare genetic disorders, we continue to encounter individuals presenting with syndromic manifestations. Here, we have studied four affected people in three families presenting with cholestasis, congenital diarrhea, impaired hearing, and bone fragility. Whole-exome sequencing of all affected individuals and their parents identified biallelic mutations in Unc-45 Myosin Chaperone A (UNC45A) as a likely driver for this disorder. Subsequent in vitro and in vivo functional studies of the candidate gene indicated a loss-of-function paradigm, wherein mutations attenuated or abolished protein activity with concomitant defects in gut dev…

A lipidomic cell-based assay for studying drug-induced phospholipidosis and steatosis

2017

Phospholipidosis and steatosis are two toxic effects, which course with overaccumulation of different classes of lipids in the liver. MS-based lipidomics has become a powerful tool for the comprehensive determination of lipids. LC-MS lipid profiling of HepG2 cells is proposed as an in vitro assay to study and anticipate phospholipidosis and steatosis. Cells with and without pre-incubation with a mixture of free fatty acids (FFA) (i.e., oleic and palmitic) were exposed to a set of well-known steatogenic and phospholipidogenic compounds. The use of FFA pre-loading accelerated the accumulation of phospholipids thus leading to a better discrimination of phospholipidosis, and magnified the lipid…

Nutraceuticals as an Important Part of Combination Therapy in Dyslipidaemia

2017

Several risk factors such as abnormality of lipid metabolism (e.g. high levels of low-density lipoprotein cholesterol (LDL-C), elevated triglycerides and low levels of high-density lipoprotein cholesterol (HDL-C)) play a central role in the aetiology of cardiovascular disease (CVD). Nutraceutical combination together with a cholesterol- lowering action, when associated with suitable lifestyle, should furnish an alternative to pharmacotherapy in patients reporting statin-intolerance and in subjects at low cardiovascular risk. The present review is focused on nutraceuticals and their synergetic combinations demonstrating a beneficial effect in the management of dyslipidaemia. Several nutraceu…

MODULATION OF GRO-ALPHA AND TNF-ALPHA PRODUCTION BY PERIPHERAL BLOOD MONONUCLEAR CELLS TREATED WITH KILLED HELICOBACTER PYLORI.

2007

GRO-alpha seems to play an important role in recruiting and activating neutrophils during Helicobacter pylori infection. In the present study, we examined how treatment with killed H. pylori or/and live H. pylori may differentially influence the in vitro GRO-alpha and TNF-alpha release by peripheral blood mononuclear cells (PBMC). The amounts of TNF-alpha and GRO-alpha produced by PBMC after stimulation with live H. pylori were higher than those produced after stimulation with a combination of killed and live H. pylori and the latter were higher than those produced after stimulation with killed H. pylori. In conclusion, the treatment of peripheral blood mononuclear cells with killed H. pyl…

Effects of the LPA1 Receptor Deficiency and Stress on the Hippocampal LPA Species in Mice

2019

Lysophosphatidic acid (LPA) is an important bioactive lipid species that functions in intracellular signaling through six characterized G protein-coupled receptors (LPA1-6). Among these receptors, LPA1 is a strong candidate to mediate the central effects of LPA on emotion and may be involved in promoting normal emotional behaviors. Alterations in this receptor may induce vulnerability to stress and predispose an individual to a psychopathological disease. In fact, mice lacking the LPA1 receptor exhibit emotional dysregulation and cognitive alterations in hippocampus-dependent tasks. Moreover, the loss of this receptor results in a phenotype of low resilience with dysfunctional coping in res…