107 research outputs found
The prodromal phase of Parkinson\u2019s disease: a mouse model study focused on alpha-synuclein pathology and dysfunction in the colon
Parkinson\u2019s disease (PD) is the most common movement disorder and the second most common
neurodegenerative disorder, with a prevalence of 1 to 2 individuals per 1000 at any age,
increasing to 1% of the population above 60 years. The pathological hallmarks of PD are neuronal
proteinaceous inclusions called Lewy bodies and neurites \u2013 rich in alpha-synuclein (\u3b1S) \u2013 and
death of dopaminergic neurons in the pars compacta of the substantia nigra, which can only be
detected in patients\u2019 brains post mortem. Diagnosis is mainly based on the observation of the
typical motor symptoms (tremor, rigidity, bradykinesia) caused by these molecular alterations.
Although PD is considered a movement disorder, patients also suffer from a variety of non motor
alterations, some of which (e.g. constipation) can occur even decades before the onset of the
motor ones. Moreover, Lewy pathology has been found in patients not only in the central (CNS),
but also in the peripheral and enteric nervous systems (ENS), suggesting a correlation between \u3b1S
inclusions in these sites and non motor symptoms, and a possible spreading of the pathology from
the periphery to the brain. This study is focused on gastrointestinal (GI) dysfunctions and
specifically constipation, for which the relationship with PD development is still poorly
understood.
For this research we used a transgenic (Tg) mouse model over-expressing human A53T \u3b1S under
the control of the murine PrP promoter (line G2-3), one of the first genetic model developed to
study \u3b1-synucleinopathies (which include PD). These mice develop neurological abnormalities
after 9 months of age that manifest with motor symptoms which become progressively more
severe culminating into a fatal paralysis within 14-21 days. Diseased mice show an accumulation
of intracellular, phosphorylated and ubiquitinated \u3b1S inclusions, neuroinflammation and neuronal
degeneration in the CNS. For the purpose of this study, sick \u3b1S Tg mice at 12-14 months,
presymptomatic mice at 1, 2, 3, 6, 9 and 12 (if still healthy) months, and age-matched nTg
littermate controls were used. Presymptomatic \u3b1S Tg mice displayed a drastic delay in GI transit
time of almost 2 hours from 3 months old that increased with age, reaching more than 3 hours
delay at 6 months. Such delay was associated with abnormal formation of stools for \u3b1S Tgs, that
resulted in less abundant but longer pellet excreted, although normal for dry and wet weight. After
that we recorded the contractile activity from longitudinal and circular muscle preparations of
colon and ileum, to verify the intestinal function. In line with our previous observations,
electrically evoked contractions of the colon, but not of the ileum, showed a reduced response in
both muscle layers in \u3b1S Tg mice already at 3 months of age, mainly due to an impaired
cholinergic transmission of the ENS. Furthermore, molecular analyses were carried out to check
on \u3b1S enteric distribution. Interestingly, insoluble and aggregated \u3b1S was found in enteric neurons
in both myenteric and submucosal plexi only in the colon and not in the small intestine of 3 months old Tg mice, and exacerbated with age, mimicking the increase in transit delay and
contraction deficits showed in behavioral and electrical recording experiments.
Following this GI characterization of PrP A53T \u3b1S Tg mice, we designed a disease modifying
therapy to be carried out with an antisense oligonucleotide (ASO) against \u3b1S, in presymptomatic
animals. After an in vitro evaluation, the selected ASO was administred to 10 weeks old Tg mice
for 7 days, through osmotic pumps or rectal administration. Very surprisingly, Tg mice which
received the ASO displayed a significant reduction in their GI transit time compared to the values
before starting the treatment and to the PBS control group, for both administration routes.
Together with the improvement in constipation, ASO treatment induced a reduction, although not
significant, of the total level of \u3b1S in the distal colon for both delivery methods.
This research demonstrates for the first time that the PrP human A53T \u3b1S Tg mice line G2-3 is a
unique model to investigate GI dysfunction in prodromal PD, thanks to the net spatio-temporal
separation of \u3b1S-driven pathologies in the ENS and in the CNS. Moreover, the promising results
obtained in this model by using an ASO peripherally support the correlation between GI behavior
and \u3b1S levels and the hypothesis that lowering the total level of \u3b1S can be a successful disease
modifying therapy against PD
Sul Trasporto Ottimo
La teoria del trasporto ottimo consiste nel cercare un trasferimento efficiente di massa da un'area di origine a una di destinazione. Tale problema fu analizzato per la prima volta da Gaspard Monge nel XVIII secolo e, in seguito nel XX secolo, da Leonid Kantorovich. Una notevole conseguenza dei loro studi è che questi permettono di definire una metrica nello spazio delle misure di probabilità , definite su uno spazio sufficientemente regolare (uno spazio “polacco”): la distanza di Wasserstein. Questo permette di offrire una definizione geodetica, e dunque dinamica, tra due misure. Questo concetto è formalizzato in modo rigoroso dall’algoritmo di Benamou-Brenier. In questa tesi, dopo averli opportunamente introdotti, sfrutteremo gli argomenti per analizzare un problema di ottimizzazione di forma di tipo isoperimetrico, dove il classico perimetro di un insieme risulta in competizione con un termine repulsivo definito per mezzo della distanza di Wasserstein. Tale problema è stato recentemente introdotto da Peletier e Roger per descrivere la localizzazione parziale delle membrane cellulari a doppio strato lipidico. L’analisi che riportiamo è stata prodotta da Goldman e Candau-Tilh in un recente articolo. Precisamente, si mostra che insiemi ottimi esistono sempre, e che nel regime in cui la tensione superficiale (i.e. perimetro) risulta dominante, questi si localizzano stabilmente in forme sferiche. Tale analisi richiede lo studio di strumenti avanzati che stanno all’intersezione tra la teoria classica del trasporto ottimo, la regolarità per insiemi isoperimetrici e una moderna formulazione di principi di concentrazione-compattezza
Plasma p-tau181, neurofilament light chain and association with cognition in Parkinson's disease
Early identification of cognitive impairment in Parkinson’s disease (PD) has important clinical and research implications. The aim of our study was to investigate the role of plasma tau phosphorylated at amino acid 181 (p-tau181) and plasma neurofilament light chain (NfL) as biomarkers of cognition in PD. Baseline concentrations of plasma p-tau181 and NfL were measured in a cohort of 136 patients with PD and 63 healthy controls (HC). Forty-seven PD patients were followed up for up to 2 years. Cross-sectional and longitudinal associations between baseline plasma biomarkers and cognitive progression were investigated using linear regression and linear mixed effects models. At baseline, plasma p-tau181 concentration was significantly higher in PD subjects compared with HC (p = 0.026). In PD patients, higher plasma NfL was associated with lower MMSE score at baseline, after adjusting for age, sex and education (p = 0.027). Baseline plasma NfL also predicted MMSE decline over time in the PD group (p = 0.020). No significant association between plasma p-tau181 concentration and baseline or longitudinal cognitive performance was found. While the role of p-tau181 as a diagnostic biomarker for PD and its relationship with cognition need further elucidation, plasma NfL may serve as a feasible, non-invasive biomarker of cognitive progression in PD
Costs and effectiveness of influenza vaccination: a systematic review
Background: Seasonal influenza can cause a significant public health burden. Vaccination is proposed as the most effective measure to prevent influenza and related undesired outcomes. Objective: To estimate the efficiency of influenza vaccination. Methods: A literature review of economic evaluations of influenza vaccinations, published over the last 5 years, was performed using MEDLINE (through PubMed), Web of Science and Scopus. Results: 935 papers were identified and 30 were selected, including studies performed in different population subgroups: general population, children, adults, elderly, pregnant women and high risk patients. Twenty-one studies were performed in Europe and in US. The majority of the studies were carried out on elderly patients and children. All except one were cost-effectiveness analyses and reported influenza vaccination as a cost-saving or cost-effective intervention. Conclusions: Vaccination strategies are economically favourable in a range of countries and sub-groups of patients.
Management of Microbiological Contamination of the Water Network of a Newly Built Hospital Pavilion
The good installation, as well as commissioning plan, of a water network is a crucial step in reducing the risk of waterborne diseases. The aim of this study was to monitor the microbiological quality of water from a newly built pavilion before it commenced operation. Overall, 91 water samples were tested for coliforms, Escherichia coli, enterococci, Pseudomonas aeruginosa and Legionella at three different times: T0 (without any water treatment), T1 (after treatment with hydrogen peroxide and silver ions at initial concentration of 20 mg/L and after flushing of water for 20 min/day for seven successive days) and T2 (15 days later). Coliforms were detected in 47.3% of samples at T0, 36.3% at T1 and 4.4% at T2. E. coli was isolated in 4.4% of the samples only at T1, while enterococci appeared in 12.1% of the samples at T1 and in 2.2% at T2. P. aeruginosa was isolated in 50.5% of the samples at T0, 29.7% at T1 and 1.1% at T2. Legionella pneumophila serogroup 8 was isolated in 80.2% of the samples at T0, 36.3% at T1 and 2.2% at T2. Our results confirmed the need for a water safety plan in new hospital pavilions to prevent the risk of waterborne diseases
Plasma Neurofilament Light and p-tau181 and Risk of Psychosis in Parkinson's Disease
BACKGROUND: Neuropsychiatric symptoms are common and important to people with Parkinson's disease (PD), but their etiology is poorly understood. Plasma neurofilament light (NfL) and p-tau181 are biomarkers of neuro-axonal degeneration and tau pathology respectively which have yet to be explored in association with the affective and psychotic symptoms in PD. OBJECTIVE: To investigate the relationship between plasma NfL and p-tau181 with the affective and psychotic symptoms in PD. METHODS: We assessed the baseline concentration of plasma NfL and p-tau181 in a cohort of 108 patients with PD and 38 healthy controls. A subgroup of patients (n = 63) was assessed annually with clinical measures for up to 7 years. Psychotic symptoms were assessed using Non-Motor Symptom Scale with affective symptoms measured in the Hospital Anxiety and Depression Scale. RESULTS: Baseline plasma NfL was a significant predictor of psychotic symptoms longitudinally across the study adjusted for age, Hoehn and Yahr stage, duration of follow up, duration of disease, baseline levodopa and dopamine agonist medication, and baseline cognition: (OR 8.15 [95% CI 1.40-47.4], p = 0.020). There was no association between NfL concentration and the cumulative prevalence of affective symptoms. Plasma p-tau181 concentration was not associated with psychotic or affective symptoms. CONCLUSION: These findings suggest psychotic symptoms are associated with greater neurodegeneration in PD. Further studies are needed to explore NfL as a potential biomarker for psychosis in PD
Enteric α-synuclein impairs intestinal epithelial barrier through caspase-1-inflammasome signaling in Parkinson's disease before brain pathology
Bowel inflammation, impaired intestinal epithelial barrier (IEB), and gut dysbiosis could represent early events in Parkinson’s disease (PD). This study examined, in a descriptive manner, the correlation among enteric α-synuclein, bowel inflammation, impairments of IEB and alterations of enteric bacteria in a transgenic (Tg) model of PD before brain pathology. Human A53T α-synuclein Tg mice were sacrificed at 3, 6, and 9 months of age to evaluate concomitance of enteric inflammation, IEB impairments, and enteric bacterial metabolite alterations during the early phases of α-synucleinopathy. The molecular mechanisms underlying the interplay between α-synuclein, activation of immune/inflammatory responses and IEB alterations were investigated with in vitro experiments in cell cultures. Tg mice displayed an increase in colonic levels of IL-1β, TNF, caspase-1 activity and enteric glia activation since 3 months of age. Colonic TLR-2 and zonulin-1 expression were altered in Tg mice as compared with controls. Lipopolysaccharide levels were increased in Tg animals at 3 months, while fecal butyrate and propionate levels were decreased. Co-treatment with lipopolysaccharide and α-synuclein promoted IL-1β release in the supernatant of THP-1 cells. When applied to Caco-2 cells, the THP- 1-derived supernatant decreased zonulin-1 and occludin expression. Such an effect was abrogated when THP-1 cells were incubated with YVAD (caspase-1 inhibitor) or when Caco-2 were incubated with anakinra, while butyrate incubation did not prevent such decrease. Taken together, early enteric α-synuclein accumulation contributes to compromise IEB through the direct activation of canonical caspase-1-dependent inflammasome signaling. These changes could contribute both to bowel symptoms as well as central pathology.Bowel inflammation, impaired intestinal epithelial barrier (IEB), and gut dysbiosis could represent early events in Parkinson’s disease (PD). This study examined, in a descriptive manner, the correlation among enteric α-synuclein, bowel inflammation, impairments of IEB and alterations of enteric bacteria in a transgenic (Tg) model of PD before brain pathology. Human A53T α-synuclein Tg mice were sacrificed at 3, 6, and 9 months of age to evaluate concomitance of enteric inflammation, IEB impairments, and enteric bacterial metabolite alterations during the early phases of α-synucleinopathy. The molecular mechanisms underlying the interplay between α-synuclein, activation of immune/inflammatory responses and IEB alterations were investigated with in vitro experiments in cell cultures. Tg mice displayed an increase in colonic levels of IL-1β, TNF, caspase-1 activity and enteric glia activation since 3 months of age. Colonic TLR-2 and zonulin-1 expression were altered in Tg mice as compared with controls. Lipopolysaccharide levels were increased in Tg animals at 3 months, while fecal butyrate and propionate levels were decreased. Co-treatment with lipopolysaccharide and α-synuclein promoted IL-1β release in the supernatant of THP-1 cells. When applied to Caco-2 cells, the THP-1-derived supernatant decreased zonulin-1 and occludin expression. Such an effect was abrogated when THP-1 cells were incubated with YVAD (caspase-1 inhibitor) or when Caco-2 were incubated with anakinra, while butyrate incubation did not prevent such decrease. Taken together, early enteric α-synuclein accumulation contributes to compromise IEB through the direct activation of canonical caspase-1-dependent inflammasome signaling. These changes could contribute both to bowel symptoms as well as central pathology
On the origin and propagation of the COVID-19 outbreak in the Italian Province of Trento, a tourist region of Northern Italy
15openInternationalItalian coauthor/editorBackground: Trentino is an Italian province with a tourism-based economy, bordering the regions of Lombardy and Veneto, where the two earliest and largest outbreaks of COVID-19 occurred in Italy. The earliest cases in Trentino were reported in the first week of March 2020, with most of the cases occurring in the winter sport areas in the Dolomites mountain range. The number of reported cases decreased over the summer months and was followed by a second wave in the autumn and winter of 2020. Methods: we performed high-coverage Oxford Nanopore sequencing of 253 positive SARS-CoV-2 swabs collected in Trentino between March and December 2020. Results: in this work, we analyzed genome sequences to trace the routes through which the virus entered the area, and assessed whether the autumnal resurgence could be attributed to lineages persisting undetected during summer, or as a consequence of new introductions. Conclusions: Comparing the draft genomes analyzed with a large selection of European sequences retrieved from GISAID we found that multiple introductions of the virus occurred at the early stage of the epidemics; the two epidemic waves were unrelated; the second wave was due to reintroductions of the virus in summer when traveling restrictions were upliftedopenBianco, Luca; Moser, Mirko; Silverj, Andrea; Micheletti, Diego; Lorenzin, Giovanni; Collini, Lucia; Barbareschi, Mattia; Lanzafame, Paolo; Segata, Nicola; Pindo, Massimo; Franceschi, Pietro; Rota-Stabelli, Omar; Rizzoli, Annapaola; Fontana, Paolo; Donati, ClaudioBianco, L.; Moser, M.; Silverj, A.; Micheletti, D.; Lorenzin, G.; Collini, L.; Barbareschi, M.; Lanzafame, P.; Segata, N.; Pindo, M.; Franceschi, P.; Rota-Stabelli, O.; Rizzoli, A.; Fontana, P.; Donati, C
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