302 research outputs found
Hygienic characteristics and microbiological hazard identification in horse and donkey raw milk
Today the interest toward horse (Equus caballus) and donkey (Equus asinus) milk for human consumption is receiving a renewed attention because of its particular composition, hypoallergenicity, and nutraceutical properties. The realistic perspective of global use of this aliment in balanced diets, especially for infancy and geriatrics, poses the need for a more in depth knowledge on milk hygiene and on the health status of dairy animals, as a prerequisite of consumers' safety. The aim of this paper was to review the available literature on the health and hygiene parameters as well as on the potential microbiological hazards in horse and donkey milk and the risks related to their consumption. Both microbial contamination and somatic cell count are reasonably low in equine milk and also the presence of pathogens, like Escherichia coli O157, Salmonella spp., Campylobacter spp., Yersinia enterocolitica, Brucella spp., Mycobacterium spp., Bacillus cereus, Cronobacter sakazakii, Streptococcus equi subsp. zooepidemicus, Rhodococcus equi, Streptococcus dysgalactiae subsp. equisimilis, Clostridium difficile and Burkholderia mallei is low. However, in those regions of the world where the prevalence of Brucella spp. and Rhodococcus equi is high, the alimentary risks could increase. Similarly, in areas with higher incidence of immunocompromised people, the increased risks should be warned not only for pathogens but also for opportunistic microbiota
Occurrence, Diversity of Listeria spp. Isolates from Food and Food-Contact Surfaces and the Presence of Virulence Genes
This study evaluates the hazards posed by foodborne bacteria of the Listeria genus by analyzing the occurrence, diversity and virulence of Listeria spp.in food and food-manufacturing plants. Seventy-five isolates obtained from the routine analysis of 653 samples taken by three diagnostic laboratories in Northern Italy were genotypically differentiated by Repetitive Extragenic Palindrome (rep) PCR, with the GTG5 primer identified by sequencing the 16S rRNA gene and examined by specific PCR tests for the presence of L. monocytogenes virulence determinants occasionally found to occur in other species of the genus. Within this sample, 76% (n = 57) isolates were identified as L. innocua, 16% (n = 12) as L. monocytogenes, 6.6% (n = 5) as L. welshimeri and 1.3% (n = 1) as L. seeligeri. All L. monocytogenes isolates belonged to the serotype 1/2a and were predicted to be virulent for the presence of the inlJ internalin gene. Potentially virulent strains of L. innocua, L. seeligeri and L. welshimeri, carrying the L. monocytogenesinlA gene and/or hly gene, were identified, and most isolates were found to possess the toxin–antitoxin system mazEF for efficient adaptation to heat shock. Results indicated the need to reinforce food-contamination-prevention measures against all Listeria species by defining efficiently their environmental distribution
Traditional dairy products can supply beneficial microorganisms able to survive in the gastrointestinal tract
Abstract Little is known about the role of traditional dairy products in naturally supplying beneficial microorganisms able to survive in the human gastrointestinal tract (GIT). To investigate this aspect, a fresh artisanal Pasta Filata cheese was administered daily to 18 healthy children, 3–6 years of age, for seven days. Counts and type of lactic acid bacteria (LAB) and propionic acid bacteria (PAB) were carried out on the cheese and children's faeces before and after cheese consumption. In most cases, statistically significant increases of presumptive LAB were observed after seven days from suspension compared to values before and at the end of consumption. Based on repetitive element palindromic PCR (rep-PCR) genotyping, six cheese isolates were identical to faecal isolates. Identity was confirmed by sequencing regions of clpP and rpoD genes for LAB and pepN and proW genes for PAB. Among those cheese isolates P. freudenreichii S-1-P, L. plantarum S-2-2 and L. helveticus S-2-6 stimulated the production of high interleukin 10 (IL-10) and low tumor necrosis factor alpha (TNF-α) levels by peripheral blood mononuclear cells (PBMC). Therefore they could exert anti-inflammatory effects in vivo. Results suggested that traditional dairy products should be more efficiently exploited as a natural source of health-promoting microorganisms
Glucose-6-phosphate tips the balance in modulating apoptosis in cerebellar granule cells
AbstractA metabolic shift from oxidative phosphorylation to glycolysis (i.e. the Warburg effect) occurs in Alzheimer’s disease accompanied by an increase of both activity and level of HK-I. The findings reported here demonstrate that in the early phase of apoptosis VDAC1 activity, but not its protein level, progressively decreases, in concomitance with the physical interaction of HK-I with VDAC1. In the late phase of apoptosis, glucose-6-phosphate accumulation in the cell causes the dissociation of the two proteins, the re-opening of the channel and the recovery of VDAC1 function, resulting in a reawakening of the mitochondrial function, thus inevitably leading to cell death
NGF-Dependent Changes in Ubiquitin Homeostasis Trigger Early Cholinergic Degeneration in Cellular and Animal AD-Model
Basal forebrain cholinergic neurons (BFCNs) depend on nerve growth factor (NGF) for their survival/differentiation and innervate cortical and hippocampal regions involved in memory/learning processes. Cholinergic hypofunction and/or degeneration early occurs at prodromal stages of Alzheimer’s disease (AD) neuropathology in correlation with synaptic damages, cognitive decline and behavioral disability. Alteration(s) in ubiquitin-proteasome system (UPS) is also a pivotal AD hallmark but whether it plays a causative, or only a secondary role, in early synaptic failure associated with disease onset remains unclear. We previously reported that impairment of NGF/TrkA signaling pathway in cholinergic-enriched septo-hippocampal primary neurons triggers “dying-back” degenerative processes which occur prior to cell death in concomitance with loss of specific vesicle trafficking proteins, including synapsin I, SNAP-25 and α-synuclein, and with deficit in presynaptic excitatory neurotransmission. Here, we show that in this in vitro neuronal model: (i) UPS stimulation early occurs following neurotrophin starvation (-1 h up to -6 h); (ii) NGF controls the steady-state levels of these three presynaptic proteins by acting on coordinate mechanism(s) of dynamic ubiquitin-C-terminal hydrolase 1 (UCHL-1)-dependent (mono)ubiquitin turnover and UPS-mediated protein degradation. Importantly, changes in miniature excitatory post-synaptic currents (mEPSCs) frequency detected in -6 h NGF-deprived primary neurons are strongly reverted by acute inhibition of UPS and UCHL-1, indicating that NGF tightly controls in vitro the presynaptic efficacy via ubiquitination-mediated pathway(s). Finally, changes in synaptic ubiquitin and selective reduction of presynaptic markers are also found in vivo in cholinergic nerve terminals from hippocampi of transgenic Tg2576 AD mice, even from presymptomatic stages of neuropathology (1-month-old). By demonstrating a crucial role of UPS in the dysregulation of NGF/TrkA signaling on properties of cholinergic synapses, these findings from two well-established cellular and animal AD models provide novel therapeutic targets to contrast early cognitive and synaptic dysfunction associated to selective degeneration of BFCNs occurring in incipient early/middle-stage of disease
A peptide containing residues 26–44 of tau protein impairs mitochondrial oxidative phosphorylation acting at the level of the adenine nucleotide translocator
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Effects of home-made boiling of bovine raw milk on its microbiological quality
The consumption of raw milk in Italy is allowed only "after boiling". The aim of this research was to bet-ter understand how the heat treatment of raw milk performed at home by consumers assures their mi-crobiological safety. 50 samples of raw milk (each sample 500 ml) provided to consumers who regularly buy raw milk from self-service automatic vending machines were followed from delivery till to after do-mestic heat treatment. Heating was performed by consumers according to their habits. The 50 samples were exposed to different heat treatments of which the mildest was at 68.5 °C and the most intense was at 97.8 °C before switching off. The average of temperatures used was 89.5 °C and the mode was 93.2 °C. According to the different parameters of heat treatment observed, 35 samples of raw milk and 35 samples of heated milk were selected for microbiological and process indicator analyses. Total Microbial Count (TMC), total and fecal coliforms, Escherichia coli, Staphylococcus aureus and Bacillus cereus loads were determined. E. coli was isolated only from one sample of raw milk. No B. cereus nor S. aure-us were found in all samples. After heat treatment, 4 samples showed a residual TMC ranging between 1,7 CFU/ml and 3,2 CFU/ml, whilst the count of total and fecal coliforms were irrelevant. The test for alkaline phosphatase has showed negative in all samples of heated milk, while the test of lactoperoxi-dase was positive in 3 samples. Results indicated that the microbiological risk attributable to the consumption of home heated raw milk is low, if the consumer applies regularly a good heating process
The amino terminus of tau inhibits kinesin-dependent axonal transport: Implications for filament toxicity
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Journal of Neuroscience Research 87 (2009): 440-451, doi:10.1002/jnr.21850.The neuropathology of Alzheimer’s disease (AD) and other tauopathies is characterized
by filamentous deposits of the microtubule-associated protein tau, but the relationship between
tau polymerization and neurotoxicity is unknown. Here, we examined effects of filamentous tau
on fast axonal transport (FAT) using isolated squid axoplasm. Monomeric and filamentous forms
of recombinant human tau were perfused in axoplasm, and their effects on kinesin- and dyneindependent
FAT rates evaluated by video microscopy. While perfusion of monomeric tau at
physiological concentrations showed no effect, tau filaments at the same concentrations
selectively inhibited anterograde (kinesin-dependent) FAT, triggering the release of conventional
kinesin from axoplasmic vesicles. Pharmacological experiments indicated that the effect of tau
filaments on FAT is mediated by protein phosphatase 1 (PP1) and glycogen synthase kinase-3
(GSK-3) activities. Moreover, deletion analysis suggested that these effects depend on a
conserved 18-amino acid sequence at the amino terminus of tau. Interestingly, monomeric tau
isoforms lacking the C-terminal half of the molecule (including the microtubule binding region)
recapitulated the effects of full-length filamentous tau. Our results suggest that pathological tau
aggregation contributes to neurodegeneration by altering a regulatory pathway for FAT.Research supported by NIH awards NS049834 (N.E.L.),
AG14453 (L.I.B.), NINDS grants NS23868, NS23320, NS41170 and NS43408 (S.B.), MDA
(S.B.), ALSA (G.M, S.B), and HDSA (G.M.)
transient upregulation of translational efficiency in prodromal and early symptomatic tg2576 mice contributes to aβ pathology
Abstract Tg2576 mice show high levels of human APP protein with Swedish Mutation during prodromal and early symptomatic stages. Interestingly, this is strictly associated with unbalanced expression of its two RNA binding proteins (RBPs) regulators, the Fragile-X Mental Retardation Protein (FMRP) and the heteronuclear Ribonucleoprotein C (hnRNP C). Whether an augmentation in overall translational efficiency also contributes to the elevation of APP levels at those early developmental stages is currently unknown. We investigated this possibility by performing a longitudinal polyribosome profiling analysis of APP mRNA and protein in total hippocampal extracts from Tg2576 mice. Results showed that protein polysomal signals were exclusively detected in pre-symptomatic (1 months) and early symptomatic (3 months) mutant mice. Differently, hAPP mRNA polysomal signals were detected at any age, but a peak of expression was found when mice were 3-month old. Consistent with an early but transient rise of translational efficiency, the phosphorylated form of the initial translation factor eIF2α (p-eIF2α) was reduced at pre-symptomatic and early symptomatic stages, whereas it was increased at the fully symptomatic stage. Pharmacological downregulation of overall translation in early symptomatic mutants was then found to reduce hippocampal levels of full length APP, Aβ species, BACE1 and Caspase-3, to rescue predominant LTD at hippocampal synapses, to revert dendritic spine loss and memory alterations, and to reinstate memory-induced c-fos activation. Altogether, our findings demonstrate that overall translation is upregulated in prodromal and early symptomatic Tg2576 mice, and that restoring proper translational control at the onset of AD-like symptoms blocks the emergence of the AD-like phenotype
Does the term 'trophic' actually mean anti-amyloidogenic? The case of NGF.
The term trophic is widely used to indicate a general pro-survival action exerted on target cells by different classes of extracellular messengers, including neurotrophins (NTs), a family of low-molecular-weight proteins whose archetypal member is the nerve growth factor (NGF). The pro-survival action exerted by NTs results from a coordinated activation of multiple metabolic pathways, some of which have only recently come to light. NGF has been shown to exert a number of different, experimentally distinguishable effects on neurons, such as survival, differentiation of target neurons, growth of nerve fibers and their guidance (tropism) toward the source of its production. We have proposed a more complete definition of the NGF trophic action that should also include its newly discovered property of inhibiting the amyloidogenic processing of amyloid precursor protein (APP), which is among the first hypothesized primary trigger of Alzheimer's disease (AD) pathogenesis. This inhibitory action appears to be mediated by a complex series of molecular events and by interactions among NGF receptors (TrkA and p75), APP processing and tau metabolic fate and fun
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