539 research outputs found
Cosmological evolution of thermal relic particles in gravity
By considering gravity models, the cosmic evolution is modified with
respect to the standard CDM scenario. In particular, the thermal
history of particles results modified. In this paper, we derive the evolution
of relics particles (WIMPs) assuming a reliable cosmological solution
and taking into account observational constraints. The connection to the PAMELA
experiment is also discussed. Results are consistent with constraints coming
from BICEP2 and PLANCK experiments.Comment: 8 pages, 4 figure
Autism Spectrum Disorder and Narcolepsy: A Possible Connection That Deserves to Be Investigated.
Narcolepsy in childhood-adolescence is characterized by a high occurrence of
psychiatric comorbidities. The most frequent psychiatric disorders reported in
these patients are attention deficit/hyperactivity disorder, depression, anxiety
disorder, and schizophrenia. However, narcolepsy can be associated also with
introversion, sorrowfulness, feelings of inferiority, impaired affectivity
modulation, emotional lability, irritability, aggressiveness, and poor attention,
that have been pooled by some authors under a definition of "narcoleptic
personality." Some aspects of this "narcoleptic personality," and in particular
introversion, impaired affectivity modulation, irritability, and poor attention,
partially overlap with the clinical features of the individuals with autism
spectrum disorder, considering also those that are not regarded as core autism
symptoms. Till now, in literature the number of cases affected by both narcolepsy
and autism spectrum disorder (seven patients) has been clearly too small to
demonstrate the presence of a pathogenetic link between these two conditions, but
this possible connection has not yet been adequately investigated, despite the
presence of several points in common. The finding of a connection between
narcolepsy and autism spectrum disorder could boost the study of possible
etiopathogenetic mechanisms shared between these two apparently so distant
disorders. Basing on the literature data summarized in this paper, in the
diagnostic work-up of a child with narcolepsy it is essential to evaluate also
the social-communicative behavior using standardized tools in order to detect the
real recurrence of clinical features suggesting an autism spectrum disorder. At
the same time, it appears necessary to screen in the individuals with autism
spectrum disorder for the possible presence of evoking symptoms of narcolepsy
Cognitive Health of Nonagenarians in Southern Italy: A Descriptive Analysis from a Cross-Sectional, Home-Based Pilot Study of Exceptional Longevity (Cilento Initiative on Aging Outcomes Or CIAO).
Background: Nonagenarians and centenarians (NCs) are an extremely fragile population, particularly in regard to their physical and cognitive function. The aim of this study was to define the neurocognitive profiles among 29 NCs and their 49 younger cohabitants aged 50-75 years from The Cilento Initiative on Aging Outcomes (CIAO) Pilot study in the South of Italy that had provided initial hypotheses regarding positive psychological traits related to exceptional longevity. Methods: During the home visits, lifestyle information with specific questionnaires, functional autonomy and the neuropsychological Mini Mental Scale Examination (MMSE), and the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) scale were obtained by qualified study personnel. The total blood oxidative capacity was also determined by testing the reactive derivative of oxygen metabolites (d-ROM) and by the Biological Antioxidant Potential (BAP). In all individuals, the APOE genotype determination was also performed. Results: All the subjects in both groups showed high adherence to the Mediterranean Diet. None of the NCs had severe cognitive impairment, and a very low incidence of dementia was found. The data obtained on the Activities ed Instrumental Activities of Daily Living (ADL-IADL) scale showed that the majority of NCs (16/29) were autonomous in daily life activities. The comparative assessment of NCs and cohabitants showed no significant differences in the laboratory assessment of oxidative stress and APOE genotype. Conclusion: In the Cilento Region of Southern Italy, NCs seemed to have good cognitive status when compared to younger cohabitants aging 50-65 years without significant differences in oxidative stress markers or APOE genotype. These results might be related to optimal adherence to the Mediterranean diet, although other lifestyle factors and positive personality traits may also contribute to their healthy aging. Further studies on a larger population should be performed to confirm the results of this pilot study
The treatment of hyperinsulinemic hypoglycaemia in adults: an update
Treatment of hyperinsulinemic hypoglycaemia (HH) is challenging due to the rarity of this condition and the difficulty of differential diagnosis. The aim of this article is to give an overview of the recent literature on the management of adult HH
Polycystic Ovary Syndrome and Hepatic Steatosis: Could Low-Grade Chronic Inflammation Be Mediated by the Spleen?:
Polycystic Ovary Syndrome (PCOS) is characterized by an extreme variety of phenotypes and controversial metabolic implications. Hepatic Steatosis (HS) and low-grade chronic inflammation (LGCI) might be common findings in PCOS. We conducted a cross-sectional study to evaluate the LGCI and HS in young women with PCOS according to their Body Mass index (BMI), Insulin Resistance (IR), and PCOS phenotypes. Sixty young premenopausal PCOS women and 20 age-matched controls participated. Primary outcome measures were the presence/severity of HS; LGCI index evaluated as spleen longitudinal diameter (SLD) by UltraSound, C-Reactive Protein (CRP) and Interleukin (IL)-6 levels; BMI and the Homeostasis Model Assessment (HoMA) of IR. The second outcome measures were testosterone, Sex Hormone-Binding Globulin (SHBG) levels, and Free Androgen Index (FAI). The presence of HS and LGCI was not significantly different between NW and O/O patients, while there were significant differences particularly when the PCOS-women were grouped according to IR or to PCOS phenotypes. At multiple regression adjusted for BMI, HoMA-IR and the spleen size were the major determinants of the severity of HS (β= 0.36, p=0.007, and β= 0.28, p=0.034, respectively). At multiple regression SLD represented the unique predictor of FAI (β=0.32; p=0.018). In young women with PCOS, HS was detected independently from obesity and was well predicted not only by IR but also by spleen size, with variable expression of the liver-spleen axis across the different PCOS subtypes. A possible role of the spleen in determining LGCI also in women with PCOS is emphasized
Aging yeast gain a competitive advantage on non-optimal carbon sources
Animals, plants and fungi undergo an aging process with remarkable physiological and molecular similarities, suggesting that aging has long been a fact of life for eukaryotes and one to which our unicellular ancestors were subject. Key biochemical pathways that impact longevity evolved prior to multicellularity, and the interactions between these pathways and the aging process therefore emerged in ancient single-celled eukaryotes. Nevertheless, we do not fully understand how aging impacts the fitness of unicellular organisms, and whether such cells gain a benefit from modulating rather than simply suppressing the aging process. We hypothesized that age-related loss of fitness in single-celled eukaryotes may be counterbalanced, partly or wholly, by a transition from a specialist to a generalist life-history strategy that enhances adaptability to other environments. We tested this hypothesis in budding yeast using competition assays and found that while young cells are more successful in glucose, highly aged cells outcompete young cells on other carbon sources such as galactose. This occurs because aged yeast divide faster than young cells in galactose, reversing the normal association between age and fitness. The impact of aging on single-celled organisms is therefore complex and may be regulated in ways that anticipate changing nutrient availability. We propose that pathways connecting nutrient availability with aging arose in unicellular eukaryotes to capitalize on age-linked diversity in growth strategy and that individual cells in higher eukaryotes may similarly diversify during aging to the detriment of the organism as a whole
MOLECULAR CHARACTERISATION OF A NOVEL ADP-RIBOSYLATING PUTATIVE TOXIN OF NEISSERIA MENINGITIDIS
Molecular characterisation of a novel ADP-ribosylating putative toxin of Neisseria meningitidis
VEGGIi D, *BALDUCCI E, MASIGNANI V, DI MARCELLO F, SAVINO S, ARICO’ B, COMANDUCCI M, PIZZA M, RAPPUOLI R
IRIS, Chiron SpA, Via Fiorentina 1, 53100 Siena Italy; *Dipartimento Scienze morfologiche e Biochimiche Comparate, UniversitĂ degli Studi di Camerino, Camerino, Italy
Session: Surface antigens
Introduction: By computer analysis on the Neisseria meningitidis (serogroup B, MC 58 strain) genome sequence, a protein with a feature similar to known bacterial ADP-ribosylating toxins (CT produced by Vibrio cholerae, LT by Escherichia coli and PT by Bordetella pertussis) has been identified. Enzymatic assay has shown that this protein (NM-ADPRT) possesses both NAD glycohydrolase and ADP-ribosyltransferase activity. In this study we describe the identification of the putative catalytic residues, their site-directed mutagenesis, and the resulting activity of the mutants.
Materials and methods: The novel NM-ADPRT and the correspondent mutants, were expressed in E. coli as C-terminus His-tag protein fusions. Site-directed mutagenesis was performed using the Multi Site-Directed Mutagenesis Kit (QuikChange). Recombinant NM-ADPRT forms were purified from E. coli in their soluble form by metal chelate affinity chromatography.
Both the wild-type and the mutants were assayed for their ADP-ribosylation and NAD-glycohydolase activites, using [adenine –U-14C] NAD and agmatine as ADP-ribose acceptor. Antisera against NM-ADPRT and the mutant derivatives were obtained by immunization of CD1 mice. 20μg of each recombinant protein were given i.p. together with CFA for the first dose and IFA for the second (day 21) and the third (day 35) booster doses. Blood sample were taken on days 34 and 49. Immune sera were used in western blot and tested in a bactericidal assay.
Results and discussion: On the basis of sequence homology of NM-ADPRT with LT, CT and PT we have identified the putative residues involved in enzymatic activity. These residues have been changed by site-directed mutagenesis and the purified mutant toxins have been tested for both ADP-ribosylating and NAD-glycohydrolase activities. Interestingly, some of the mutants show reduced or abolished enzymatic activity indicating that the identified residues play a role in catalysis. Antisera against the wild-type and mutant toxins have bactericidal activity. The titers induced by two mutants were higher than those induced by the wild-type form. These data suggest that the mutations introduced could influence not only the enzymatic activity but also the in vivo stability of the toxin.
Conclusion: A novel ADP-ribosyltransferase has been identified in meningococcus B. Catalytic residues have been predicted by sequence homology and their role in catalysis has been confirmed by site-directed mutagenesis. These molecules are also able to induce a bactericidal response
A comparative blind study between skin biopsy and seed amplification assay to disclose pathological α-synuclein in RBD
To compare the diagnostic accuracy of the immunofluorescence (IF) technique and aSyn-seed amplification assay (aSyn-SAA) of skin and cerebrospinal fluid (CSF) in disclosing pathological α-syn in idiopathic idiopathic REM sleep behavior disorder (iRBD) as early phase of a synucleinopathy. We prospectively recruited 41 patients with iRBD and 40 matched clinical controls including RBD associated with type 1 Narcolepsy (RBD-NT1, 21 patients), iatrogenic causes (2 pt) or OSAS (6 pt) and 11 patients with peripheral neuropathies. IF from samples taken by skin biopsy and aSyn-SAA from skin and CSF samples were analysed blinded to the clinical diagnosis. IF showed a good diagnostic accuracy (89%) that was lower in the case of skin and CSF-based aSyn-SAA (70% and 69%, respectively) because of a lower sensitivity and specificity. However, IF showed a significant agreement with CSF aSyn-SAA. In conclusion, our data may favor the use of skin biopsy and aSyn-SAA as diagnostic tools for a synucleinopathy in iRBD
Chromatic Pupillometry in Isolated Rapid Eye Movement Sleep Behavior Disorder
Background: Melanopsin retinal ganglion cell (mRGC)-mediated pupillary light reflex (PLR) abnormalities have been documented in several neurodegenerative disorders including Parkinson's disease. Overall, isolated rapid eye movement (REM) sleep behavior disorder (iRBD) represents the strongest prodromal risk factor for impending α-synucleinopathies. Objectives: To quantitatively compare PLR and mRGC-mediated contribution to PLR in 16 iRBD patients and 16 healthy controls. Methods: iRBD and controls underwent extensive neuro-ophthalmological evaluation and chromatic pupillometry. In iRBD, PLR metrics were correlated with clinical variables and with additional biomarkers including REM atonia index (RAI), DaTscan, and presence of phosphorylated-α-synuclein (p-α-syn) deposition in skin biopsy. Results: We documented higher baseline pupil diameter and decreased rod-transient PLR amplitude in iRBD patients compared to controls. PLR rod-contribution correlated with RAI. Moreover, only iRBD patients with evidence of p-α-syn deposition at skin biopsy showed reduced PLR amplitude compared to controls. Conclusion: The observed PLR abnormalities in iRBD might be considered as potential biomarkers for the risk stratification of phenoconversion of the disease. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
The factor H binding protein of Neisseria meningitidis interacts with xenosiderophores in vitro.
The factor H binding protein (fHbp) is a key virulence factor of Neisseria meningitidis that confers to the bacterium the ability to resist killing by human serum. The determination of its three-dimensional structure revealed that the carboxyl terminus of the protein folds into an eight-stranded ß barrel. The structural similarity of this part of the protein to lipocalins provided the rationale for exploring the ability of fHbp to bind siderophores. We found that fHbp was able to bind in vitro siderophores belonging to the cathecolate family and mapped the interaction site by nuclear magnetic resonance. Our results indicated that the enterobactin binding site was distinct from the site involved in binding to human factor H and stimulates new hypotheses about possible multiple activities of fHbp.Full Tex
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