111 research outputs found

    Monitoring commercial starter culture development in presence of red grape pomace powder to produce polyphenol-enriched fresh ovine cheeses at industrial scale level

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    Red grape Nero d'Avola cultivar grape pomace powder (GPP) was applied during fresh ovine cheese production in order to increase polyphenol content. Before cheeses were produced, the bacteria of a freeze-dried commercial starter culture were isolated and tested in vitro against GPP. Two dominant strains, both resistant to GPP, were identified. Thestarter culture was inoculated in pasteurized ewe's milk and the curd was divided into two bulks, one added with 1% (w/w) GPP and another one GPP-free. GPP did not influence the starter culture development, since lactic acid bacteria (LAB) counts were 109 CFU/g in both cheeses at 30 d. To exclude the interference of indigenous LAB, the pasteurized milk was analyzed, and several colonies of presumptive LAB were isolated, purified and typed. Four strains were allotted into Enterococcus and Lacticaseibacillus genera. The direct comparison of the polymorphic profiles of cheese bacteria evidenced the dominance of the starter culture over milk LAB. The addition of GPP increased cheese total phenolic compounds by 0.42 g GAE/kg. Sensory evaluation indicated that GPP-enriched cheese was well appreciated by the judges, providing evidence that GPP is a suitable substrate to increase the availability of total phenolic content in fresh ovine cheese

    Effect on the antioxidant, lipoperoxyl radical scavenger capacity, nutritional, sensory and microbiological traits of an ovine stretched cheese produced with grape pomace powder addition

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    An innovative ovine cheese enriched with red grape pomace powder (GPP) was produced to improve the functional properties of Vastedda cheese typology. Vastedda cheese making was performed adding GPP and four selected Lactococcus lactis strains (Mise36, Mise94, Mise169 and Mise190). For each strain, 40 L of pasteurized ewe’s milk was divided into two aliquots representing control and experimental trials. Control cheese (CC) production did not contain GPP, while the experimental cheese (EC) production was enriched with 1% (w/w) GPP. GPP did not slow down starter development and acid generation. Plate counts and randomly amplified polymorphic DNA (RAPD)-PCR analysis confirmed the dominance of the starters in all trials. The evolution of the physicochemical parameters showed that EC productions were characterized by lower fat content, higher protein content, and higher values of secondary lipid oxidation. Sensory evaluation indicated that the cheeses produced with the strain Mise94 were those more appreciated by the judges. Thus, the last cheeses were investigated for some functional aspects: GPP enrichment significantly increased antioxidant activity and lipoperoxyl radical scavenger capacity, confirming that grape polyphenol inclusion in cheese represents an optimal strategy for the valorization of ovine cheeses as well as winemaking industry by-products

    Deletion of the gabra2 gene results in hypersensitivity to the acute effects of ethanol but does not alter ethanol self administration

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    Human genetic studies have suggested that polymorphisms of the GABRA2 gene encoding the GABA(A) α2-subunit are associated with ethanol dependence. Variations in this gene also convey sensitivity to the subjective effects of ethanol, indicating a role in mediating ethanol-related behaviours. We therefore investigated the consequences of deleting the α2-subunit on the ataxic and rewarding properties of ethanol in mice. Ataxic and sedative effects of ethanol were explored in GABA(A) α2-subunit wildtype (WT) and knockout (KO) mice using a Rotarod apparatus, wire hang and the duration of loss of righting reflex. Following training, KO mice showed shorter latencies to fall than WT littermates under ethanol (2 g/kg i.p.) in both Rotarod and wire hang tests. After administration of ethanol (3.5 g/kg i.p.), KO mice took longer to regain the righting reflex than WT mice. To ensure the acute effects are not due to the gabra2 deletion affecting pharmacokinetics, blood ethanol concentrations were measured at 20 minute intervals after acute administration (2 g/kg i.p.), and did not differ between genotypes. To investigate ethanol's rewarding properties, WT and KO mice were trained to lever press to receive increasing concentrations of ethanol on an FR4 schedule of reinforcement. Both WT and KO mice self-administered ethanol at similar rates, with no differences in the numbers of reinforcers earned. These data indicate a protective role for α2-subunits, against the acute sedative and ataxic effects of ethanol. However, no change was observed in ethanol self administration, suggesting the rewarding effects of ethanol remain unchange

    Neurochemical Changes in the Mouse Hippocampus Underlying the Antidepressant Effect of Genetic Deletion of P2X7 Receptors.

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    Recent investigations have revealed that the genetic deletion of P2X7 receptors (P2rx7) results in an antidepressant phenotype in mice. However, the link between the deficiency of P2rx7 and changes in behavior has not yet been explored. In the present study, we studied the effect of genetic deletion of P2rx7 on neurochemical changes in the hippocampus that might underlie the antidepressant phenotype. P2X7 receptor deficient mice (P2rx7-/-) displayed decreased immobility in the tail suspension test (TST) and an attenuated anhedonia response in the sucrose preference test (SPT) following bacterial endotoxin (LPS) challenge. The attenuated anhedonia was reproduced through systemic treatments with P2rx7 antagonists. The activation of P2rx7 resulted in the concentration-dependent release of [3H]glutamate in P2rx7+/+ but not P2rx7-/- mice, and the NR2B subunit mRNA and protein was upregulated in the hippocampus of P2rx7-/- mice. The brain-derived neurotrophic factor (BDNF) expression was higher in saline but not LPS-treated P2rx7-/- mice; the P2rx7 antagonist Brilliant blue G elevated and the P2rx7 agonist benzoylbenzoyl ATP (BzATP) reduced BDNF level. This effect was dependent on the activation of NMDA and non-NMDA receptors but not on Group I metabotropic glutamate receptors (mGluR1,5). An increased 5-bromo-2-deoxyuridine (BrdU) incorporation was also observed in the dentate gyrus derived from P2rx7-/- mice. Basal level of 5-HT was increased, whereas the 5HIAA/5-HT ratio was lower in the hippocampus of P2rx7-/- mice, which accompanied the increased uptake of [3H]5-HT and an elevated number of [3H]citalopram binding sites. The LPS-induced elevation of 5-HT level was absent in P2rx7-/- mice. In conclusion there are several potential mechanisms for the antidepressant phenotype of P2rx7-/- mice, such as the absence of P2rx7-mediated glutamate release, elevated basal BDNF production, enhanced neurogenesis and increased 5-HT bioavailability in the hippocampus

    Divergent Modulation of Neuronal Differentiation by Caspase-2 and -9

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    Human Ntera2/cl.D1 (NT2) cells treated with retinoic acid (RA) differentiate towards a well characterized neuronal phenotype sharing many features with human fetal neurons. In view of the emerging role of caspases in murine stem cell/neural precursor differentiation, caspases activity was evaluated during RA differentiation. Caspase-2, -3 and -9 activity was transiently and selectively increased in differentiating and non-apoptotic NT2-cells. SiRNA-mediated selective silencing of either caspase-2 (si-Casp2) or -9 (si-Casp9) was implemented in order to dissect the role of distinct caspases. The RA-induced expression of neuronal markers, i.e. neural cell adhesion molecule (NCAM), microtubule associated protein-2 (MAP2) and tyrosine hydroxylase (TH) mRNAs and proteins, was decreased in si-Casp9, but markedly increased in si-Casp2 cells. During RA-induced NT2 differentiation, the class III histone deacetylase Sirt1, a putative caspase substrate implicated in the regulation of the proneural bHLH MASH1 gene expression, was cleaved to a ∼100 kDa fragment. Sirt1 cleavage was markedly reduced in si-Casp9 cells, even though caspase-3 was normally activated, but was not affected (still cleaved) in si-Casp2 cells, despite a marked reduction of caspase-3 activity. The expression of MASH1 mRNA was higher and occurred earlier in si-Casp2 cells, while was reduced at early time points during differentiation in si-Casp9 cells. Thus, caspase-2 and -9 may perform opposite functions during RA-induced NT2 neuronal differentiation. While caspase-9 activation is relevant for proper neuronal differentiation, likely through the fine tuning of Sirt1 function, caspase-2 activation appears to hinder the RA-induced neuronal differentiation of NT2 cells

    Effects of adult exposure to bisphenol A on genes involved in the physiopathology of rat prefrontal cortex

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    Several neurological and behavioral dysfunctions have been reported in animals exposed to bisphenol A (BPA). However, little is known about the impact of adult exposure to BPA on brain physiopathology. Here, we focused on prefrontal cortex (PFC) of rats, because it is an important area for cognitive control, complex behaviors and is altered in many psychopathologies. Gamma-aminobutyric acid (GABA) and serotonin (5-HT) systems are essential for PFC function. Therefore, we examined the effects of adult exposure to BPA on 5α-Reductase (5α-R) and cytochrome P450 aromatase (P450arom), enzymes that synthesize GABAA receptor modulators, and tryptophan hydroxylase (Tph), the rate-limiting enzyme in 5-HT biosynthesis. To gain better understanding of BPA’s action in the adult PFC, 84 genes involved in neurotoxicity were also analysed. Adult male and female rats were subcutaneously injected for 4 days with 50 µg/kg/day, the current reference safe dose for BPA. mRNA and protein levels of 5α-R, P450arom and Tph were quantified by real-time RT-PCR and Western blot. Genes linked to neurotoxicity were analyzed by PCR-Array technology. Adult exposure to BPA increased both P450arom and Tph2 expression in PFC of male and female, but decreased 5α-R1 expression in female. Moreover, we identified 17 genes related to PFC functions such as synaptic plasticity and memory, as potential targets of BPA. Our results provided new insights on the molecular mechanisms underlying BPA action in the physiopathology of PFC, but also raise the question about the safety of short-term exposure to it in the adulthood.This research was supported by grants from Ministerio de Ciencia e Innovación (BFU2008-05340) and by the Junta de Andalucía (CTS202-Endocronología y Metabolismo)

    Approaching coronavirus disease 2019: Mechanisms of action of repurposed drugs with potential activity against SARS-CoV-2

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    On March 11, 2020, the World Health Organization (WHO) declared the severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2) a global pandemic. As of July 2020, SARS-CoV-2 has infected more than 14 million people and provoked more than 590,000 deaths, worldwide. From the beginning, a variety of pharmacological treatments has been empirically used to cope with the life-threatening complications associated with Corona Virus Disease 2019 (COVID-19). Thus far, only a couple of them and not consistently across reports have been shown to further decrease mortality, respect to what can be achieved with supportive care. In most cases, and due to the urgency imposed by the number and severity of the patients\u2019 clinical conditions, the choice of treatment has been limited to repurposed drugs, approved for other indications, or investigational agents used for other viral infections often rendered available on a compassionate-use basis. The rationale for drug selection was mainly, though not exclusively, based either i) on the activity against other coronaviruses or RNA viruses in order to potentially hamper viral entry and replication in the epithelial cells of the airways, and/or ii) on the ability to modulate the excessive inflammatory reaction deriving from dysregulated host immune responses against the SARS-CoV-2. In several months, an exceptionally large number of clinical trials have been designed to evaluate the safety and efficacy of anti-COVID-19 therapies in different clinical settings (treatment or pre- and post-exposure prophylaxis) and levels of disease severity, but only few of them have been completed so far. This review focuses on the molecular mechanisms of action that have provided the scientific rationale for the empirical use and evaluation in clinical trials of structurally different and often functionally unrelated drugs during the SARS-CoV-2 pandemic

    Microbiological characterization of the biofilms of wooden shelves used for ripening of traditional raw milk cheeses produced in Sicily (South Italy).

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    The production of artisanal Sicilian cheeses is generally carried out with wooden equipment. For centuries, wood has been the main material used in cheese making due to its availability, low cost and resistance over time. Among dairy wooden equipment, the wooden vat used for milk curdling plays a role of paramount importance to inoculate the bulk milk with desired lactic acid bacteria (LAB) responsible for the acidification of the curd. In the last few years, the biofilms associated to these containers have been object of study of different research groups, mainly Italian and French, but so far, very little is known about the microbiological characteristics of the wooden shelves used for cheese ripening and their influence on the safety of the final products. With this in mind, the aim of the present study was to investigate and enumerate several microbial populations associated to the wooden shelves used for the ripening of traditional Sicilian cheeses. To this purpose, the biofilms of nine wooden shelves used for the ripening of Caciocavallo Palermitano and PDO Pecorino Siciliano made with raw cows\u2019 and raw ewes\u2019 milk, respectively, were investigated. The shelf biofilms (400 cm2) were sampled by the brushing recovery method using sterile plastic squares (Biogenetics s.r.l., Padua, Italy). The cell suspensions of wooden shelves were subjected to the decimal serial dilutions in Ringer\u2019s solution (Sigma-Aldrich, Milan, Italy). The microbiological investigation carried out by plate count involved pro-technological and spoilage/pathogenic bacterial groups and unicellular/filamentous fungi. Listeria monocytogenes, Salmonella spp. and coagulase-positive staphylococci were never detected, total coliforms were at low numbers with E. coli found only onto two shelves. The spores of clostridia were not detected in any shelf. LAB dominated the surfaces of seven shelves, but they were below the detection limit onto two shelves. In general, the dominance was showed by mesophilic LAB cocci found in the range 105 - 108 CFU/cm2. Enterococci were found only onto three wooden shelves, but almost at 2 Log cycles lower than the levels of mesophilic LAB. Pseudomonas spp. were found only onto three shelves, also positive for the presence of enterobacteria. Yeasts were found in all samples and their levels ranged between 1.60 and 6.81 Log CFU/cm2. Moulds were below the detection limit only in one sample and their levels ranged between 1.78 and 5.45 Log CFU/cm2 on the other shelves. This study represents a first report on the microbiological investigation of the biofilms associated to the wooden shelves used for cheese ripening in Sicily. The results of the present work confirmed that from a hygienic point of view, the wooden shelves do not represents a risk for the safety of consumers. However, further studies are necessary to better investigate the microbial composition of these dairy equipment at species level in order to evaluate their influence on the centripetal ripening

    Serotonin‐Elicited Amplification of Adenylate Cyclase Activity in Hippocampal Membranes from Adult Rat

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    The activity of the adenylate cyclase located in membranes prepared from hippocampus of adult rat can be stimulated by serotonin (5‐HT) (Ka= 4 x 10‐7M). The maximal effect is obtained with 10 μM 5‐HT. Freezing of the tissue decreases the 5‐HT stimulation; this stimulation is optimal in the presence of 82.5 mM Tris‐maleate buffer (pH 7.4) and 50 μM GTP. The adenylate cyclase activity of membranes prepared from cortex, hypothalamus, and colliculi of adult rats is not significantly stimulated by 5‐HT. Dopamine (DA) also stimulates adenylate cyclase located in hippocampal membranes; its effect can be blocked by haloperidol (10‐6 M), which fails to inhibit 5‐HT stimulation. Moreover, p‐chlorophenylalanine treatment for 2 weeks or selective lesion of 5‐HT axons afferent to the hippocampus increases the Vmax of 5‐HT stimulation, but fails to change that of DA stimulation. The 5‐HT stimulation can be inhibited by metergoline, spiroperidol, and pizotyline (10‐6 M), but not by the same concentrations of mianserin, ketanserine, alprenolol, phenoxybenzamine, and mepyramine. The 5‐HT stimulation of adenylate cyclase of hippocampal membranes can be mimicked by tryptamine, 5‐methoxytryptamine, bufotenine, and to a lesser extent by LSD; N‐methyltryptamine, N‐methyltryptophan, and 5‐hydroxytryptophan are inactive. Studies with kainic acid suggest that the 5‐HT recognition site (5‐HT1) linked to adenylate cyclase is located on the membrane of intrinsic hippocampal neurons. Copyright © 1983, Wiley Blackwell. All rights reserve
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