188 research outputs found
Non-motor impairments affect walking kinematics in Parkinson disease patients: A cross-sectional study
Background: In patients with Parkinson disease (PD), severe postural and gait impairments are rarely observed in early stage of disease and non-motor symptoms (NMS) are often overlooked.
Objective: This observational study aimed to characterize the impact of non-motor impairments on walking kinematics in early stages PD patients, and to assess the differences of gait parameters and NMS between PD patients with and without mild cognitive impairment (MCI).
Methods: Twenty-six patients with Modified Hoehn and Yahr Scale score≤2 were evaluated for NMS using Kings Parkinson's Pain Scale, Parkinson Fatigue Severity scale, Parkinson Anxiety Scale, Beck Depression Inventory and Epworth Sleepiness Scale, kinematic parameters through an inertial sensor and cognitive performance by a comprehensive neuropsychological battery.
Results: Fatigue had a moderate negative correlation with step cadence, and a moderate to strong positive correlation with gait duration, Timed Up and Go (TUG) and TUG Dual Task (p < 0.01). Pain showed positive moderate correlation with gait duration (p < 0.01). Twelve patients resulted affected by MCI and reported significantly worse scores in gait duration, pain and fatigue (p < 0.05). According to cognitive z scores, PD-MCI group showed a moderate negative correlation between visuospatial abilities and fatigue (p < 0.05).
Conclusions: NMS significantly affect walking kinematics whereas a limited role of cognitive status on motor performance occur in the early PD stages
Antifungal and Antibiofilm Activity of Cyclic Temporin L Peptide Analogues against Albicans and Non-Albicans Candida Species
Temporins are one of the largest families of antimicrobial peptides with both anti-inflammatory and antimicrobial activity. Herein, for a panel of cyclic temporin L isoform analogues, the antifungal and antibiofilm activities were determined against representative Candida strains, including C. albicans, C. glabrata, C. auris, C. parapsilosis and C. tropicalis. The outcomes indicated a significant anti-candida activity against planktonic and biofilm growth for four peptides (3, 7, 15 and 16). The absence of toxicity up to high concentrations and survival after infection were assessed in vivo by using Galleria mellonella larvae, and the correlation between conformation and cytotoxicity was investigated by fluorescence assays and circular dichroism (CD). By combining fluorescence spectroscopy, CD, dynamic light scattering, confocal and atomic force microscopy, the mode of action of four analogues was hypothesized. The results pinpointed that peptide 3 emerged as a non-toxic compound showing a potent antibiofilm activity and represents a promising compound for biomedical applications
Membrane association of peroxiredoxin-2 in red cells is mediated by n-terminal cytoplasmic domain of band 3
Band 3(B3),the anion transporter, is an integral membrane protein that plays a key structural role by anchor in the plasmamembrane to the spectrin-based membrane skeleton in the red cell. In addition, it also plays a critical role in the assembly of glycolytic enzymes to regulate red cell metabolism.
However, its ability to recruit proteins that can prevent membrane oxidation has not been previously explored. In this study, using a variety of experimental approaches including cross-linking studies, fluorescence and dichroic measurements,surface plasmon resonance analysis, and proteolytic digestion assays, we document that the antioxidant protein peroxiredoxin-2(PRDX2), the third most abundant cytoplasmic protein in RBCs, interacts with the cytoplasmic domain of B3. The surface electrostatic
potential analysis and stoichiometry measurements revealed that the N-terminal peptide of B3 is involved in the interaction. PRDX2 underwent a conformational change upon its binding to B3 without
losing its peroxidase activity. Hemichrome formation induced by phenylhydrazine of RBCs prevented membrane association of PRDX2, implying overlapping binding sites. Documentation of the absence of binding of PRDX2 to B3 Neapolis red cell membranes, in which the initial N-terminal 11 amino acids are deleted, enabled us to conclude that PRDX2 binds to the N-terminal cytoplasmic domain of B3 and that the first 11 amino acids of this domain are crucial for PRDX2 membrane association in intact RBCs. These findings imply yet another important role for B3 in regulating red cell membrane function
Clinical expression of facioscapulohumeral muscular dystrophy in carriers of 1-3 D4Z4 reduced alleles: Experience of the FSHD Italian National Registry
OBJECTIVES:
Facioscapulohumeral muscular dystrophy type 1 (FSHD1) has been genetically linked to reduced numbers ( 64 8) of D4Z4 repeats at 4q35. Particularly severe FSHD cases, characterised by an infantile onset and presence of additional extra-muscular features, have been associated with the shortest D4Z4 reduced alleles with 1-3 repeats (1-3 DRA). We searched for signs of perinatal onset and evaluated disease outcome through the systematic collection of clinical and anamnestic records of de novo and familial index cases and their relatives, carrying 1-3 DRA.
SETTING:
Italy.
PARTICIPANTS:
66 index cases and 33 relatives carrying 1-3 DRA.
OUTCOMES:
The clinical examination was performed using the standardised FSHD evaluation form with validated inter-rater reliability. To investigate the earliest signs of disease, we designed the Infantile Anamnestic Questionnaire (IAQ). Comparison of age at onset was performed using the non-parametric Wilcoxon rank-sum or Kruskal-Wallis test. Comparison of the FSHD score was performed using a general linear model and Wald test. Kaplan-Meier survival analysis was used to estimate the age-specific cumulative motor impairment risk.
RESULTS:
No patients had perinatal onset. Among index cases, 36 (54.5%) showed the first signs by 10 years of age. The large majority of patients with early disease onset (26 out of 36, 72.2%) were de novo; whereas the majority of patients with disease onset after 10 years of age were familial (16, 53.3%). Comparison of the disease severity outcome between index cases with age at onset before and over 10 years of age, failed to detect statistical significance (Wald test p value=0.064). Of 61 index cases, only 17 (27.9%) presented extra-muscular conditions. Relatives carrying 1-3 DRA showed a large clinical variability ranging from healthy subjects, to patients with severe motor impairment.
CONCLUSIONS:
The size of the D4Z4 allele is not always predictive of severe clinical outcome. The high degree of clinical variability suggests that additional factors contribute to the phenotype complexity
Photodegradation and ecotoxicology of acyclovir in water under UV254 and UV 254/H2O2 processes
The photochemical and ecotoxicological fate of acyclovir (ACY) through UV254 direct photolysis and in the presence of hydroxyl radicals (UV254/H2O2 process) were investigated in a microcapillary film (MCF) array photoreactor, which provided ultrarapid and accurate photochemical reaction kinetics. The UVC phototransformation of ACY was found to be unaffected by pH in the range from 4.5 to 8.0 and resembled an apparent autocatalytic reaction. The proposed mechanism included the formation of a photochemical intermediate (ϕACY = (1.62 ± 0.07)·10−3 mol ein−1) that further reacted with ACY to form by-products (k’ = (5.64 ± 0.03)·10−3 M−1 s−1). The photolysis of ACY in the presence of hydrogen peroxide accelerated the removal of ACY as a result of formation of hydroxyl radicals. The kinetic constant for the reaction of OH radicals with ACY (kOH/ACY) determined with the kinetic modeling method was (1.23 ± 0.07)·109 M−1 s−1 and with the competition kinetics method was (2.30 ± 0.11)·109 M−1 s−1 with competition kinetics. The acute and chronic effects of the treated aqueous mixtures on different living organisms (Vibrio fischeri, Raphidocelis subcapitata, D. magna) revealed significantly lower toxicity for the samples treated with UV254/H2O2 in comparison to those collected during UV254 treatment. This result suggests that the addition of moderate quantity of hydrogen peroxide (30–150 mg L−1) might be a useful strategy to reduce the ecotoxicity of UV254 based sanitary engineered systems for water reclamation
IN ChAc RED CELLS THE ABNORMALLY ACTIVATED LYN AFFECTS ANKYRIN MULTIPROTEIN COMPLEXES AND IS INHIBITED BY DASATINIB
Chorea-acanthocytosis (ChAc) is a hereditary-neurodegenerative disorder, one of the neuroacanthocytosis syndromes (NA). One of the hallmarks of NA is the presence of circulating acanthocytes, generation of which is still under investigation. Recently, we reported increased Tyr-phosphorylation state of the red blood cell (RBC) membrane proteins from ChAc patients, related to abnormal activation of Lyn, an Src family kinase (SFKs) (Blood 118; 5652; 2011). In the context of international collaboration, we further characterized Lyn signaling pathway in RBC from ChAc patients. In ChAc RBCs, we found a weakness of ankyrin - based multiprotein complex bridging the membrane to the cytoskeleton, contributing to the generation of acanthocytes. We then evaluated the state of Lyn (active-inactive) in the cytoplasmic fraction from RBC of ChAc patients. In ChAc RBCs we found higher levels of Phospho- Lyn-396, corresponding to active Lyn, compared to controls. We then evaluated whether classical Lyn inhibitors such as PP2 or Dasatinib, a pharmacological Lyn inhibitor, might block Lyn in ChAc RBCs. We found that both PP2 (0.1\u3bcM) or Dasatinib (0.1 \u3bcM) were able to efficiently inhibit Lyn in both ChAc and healthy RBCs. These data suggest that in ChAc (i) the abnormal activation of Lyn affects RBC membrane mechanical stability weakening both multiprotein complexes, bridging the membrane to the cytoskeleton; (ii) Lyn activity is inhibited by either PP2 or Dasatinib, suggesting Lyn as possible new therapeutic target in ChAc
Primary mitochondrial myopathy: Clinical features and outcome measures in 118 cases from Italy
Objective: To determine whether a set of functional tests, clinical scales, patient-reported questionnaires, and specific biomarkers can be considered reliable outcome measures in patients with primary mitochondrial myopathy (PMM), we analyzed a cohort of Italian patients. Methods: Baseline data were collected from 118 patients with PMM, followed by centers of the Italian network for mitochondrial diseases. We used the 6-Minute Walk Test (6MWT), Timed Up-and-Go Test (x3) (3TUG), Five-Times Sit-To-Stand Test (5XSST), Timed Water Swallow Test (TWST), and Test of Masticating and Swallowing Solids (TOMASS) as functional outcome measures; the Fatigue Severity Scale and West Haven-Yale Multidimensional Pain Inventory as patient-reported outcome measures; and FGF21, GDF15, lactate, and creatine kinase (CK) as biomarkers. Results: A total of 118 PMM cases were included. Functional outcome measures (6MWT, 3TUG, 5XSST, TWST, and TOMASS) and biomarkers significantly differed from healthy reference values and controls. Moreover, functional measures correlated with patients' perceived fatigue and pain severity. Patients with either mitochondrial or nuclear DNA point mutations performed worse in functional measures than patients harboring single deletion, even if the latter had an earlier age at onset but similar disease duration. Both the biomarkers FGF21 and GDF15 were significantly higher in the patients compared with a matched control population; however, there was no relation with severity of disease. Conclusions: We characterized a large cohort of PMM by evaluating baseline mitochondrial biomarkers and functional scales that represent potential outcome measures to monitor the efficacy of treatment in clinical trials; these outcome measures will be further reinvestigated longitudinally to define the natural history of PMM
Hypoxia-reperfusion affects osteogenic lineage and promotes sickle cell bone disease
Sickle cell disease (SCD) is a worldwide distributed hereditary red cell disorder, characterized by severe organ complication. Sickle bone disease (SBD) affects the large part of SCD patients and its pathogenesis has been only partially investigated. Here, we studied bone homeostasis in humanized mouse model for SCD. Under normoxia, SCD mice display bone loss and bone impairment with increased osteoclast and reduced osteoblast activity. Hypoxia/reperfusion (H/R) stress, mimicking acute vaso-occlusive crises (VOCs), increased bone turnover, osteoclast activity (RankL) and osteoclast recruitment (Rank) with up-regulation of Il6 as pro-resorptive cytokine. This was associated with further suppression of osteogenic lineage (Runx2, Sparc). In order to interfer with the development of SBD, zoledronic-acid, a potent inhibitor of osteoclast activity/osteoclastogenesis and promoter of osteogenic lineage, was used in H/R exposed mice. Zoledronic-acid markedly inhibited osteoclast activity and recruitment, promoting osteogenic lineage. The recurrent H/R stress further worsened bone structure, increased bone turnover, depressed osteoblastogenesis (Runx2, Sparc) and increased both osteoclast activity (RankL, Cathepsin k) and osteoclast recruitment (Rank) in SCD mice compared to either normoxic or single H/R episode SCD mice. Zoledronic-acid used before recurrent VOCs prevented bone impairment and promoted osteogenic lineage. Our findings support the view that SBD is related to osteoblast impairment and increased osteoclast activity resulted from local hypoxia, oxidative stress and the release of pro-resorptive cytokine such as IL6. Zoledronic acid might act on both osteoclast and osteoblast compartment as multimodal therapy to prevent SBD
Tyrosine phosphorylation modulates peroxiredoxin-2 activity in normal and diseased red cells
Peroxiredoxin-2 (Prx2) is the third most abundant cytoplasmic protein in red blood cells. Prx2 belongs to a well-known family of antioxidants, the peroxiredoxins (Prxs), that are widely expressed in mammalian cells. Prx2 is a typical, homodimeric, 2-Cys Prx that uses two cysteine residues to accomplish the task of detoxifying a vast range of organic peroxides, H2O2, and peroxynitrite. Although progress has been made on functional characterization of Prx2, much still remains to be investigated on Prx2 post-translational changes. Here, we first show that Prx2 is Tyrosine (Tyr) phosphorylated by Syk in red cells exposed to oxidation induced by diamide. We identified Tyr-193 in both recombinant Prx2 and native Prx2 from red cells as a specific target of Syk. Bioinformatic analysis suggests that phosphorylation of Tyr-193 allows Prx2 conformational change that is more favorable for its peroxidase activity. Indeed, Syk-induced Tyr phosphorylation of Prx2 enhances in vitro Prx2 activity, but also contributes to Prx2 translocation to the membrane of red cells exposed to diamide. The biologic importance of Tyr-193 phospho-Prx2 is further supported by data on red cells from a mouse model of humanized sickle cell disease (SCD). SCD is globally distributed, hereditary red cell disorder, characterized by severe red cell oxidation due to the pathologic sickle hemoglobin. SCD red cells show Tyr-phosphorylated Prx2 bound to the membrane and increased Prx2 activity when compared to healthy erythrocytes. Collectively, our data highlight the novel link between redox related signaling and Prx2 function in normal and diseased red cells
Therapeutic targeting of Lyn kinase to treat chorea-acanthocytosis
Chorea-Acanthocytosis (ChAc) is a devastating, little understood, and currently untreatable neurodegenerative disease caused by VPS13A mutations. Based on our recent demonstration that accumulation of activated Lyn tyrosine kinase is a key pathophysiological event in human ChAc cells, we took advantage of Vps13a-/- mice, which phenocopied human ChAc. Using proteomic approach, we found accumulation of active Lyn, \u3b3-synuclein and phospho-tau proteins in Vps13a-/- basal ganglia secondary to impaired autophagy leading to neuroinflammation. Mice double knockout Vps13a-/- Lyn-/- showed normalization of red cell morphology and improvement of autophagy in basal ganglia. We then in vivo tested pharmacologic inhibitors of Lyn: dasatinib and nilotinib. Dasatinib failed to cross the mouse brain blood barrier (BBB), but the more specific Lyn kinase inhibitor nilotinib, crosses the BBB. Nilotinib ameliorates both Vps13a-/- hematological and neurological phenotypes, improving autophagy and preventing neuroinflammation. Our data support the proposal to repurpose nilotinib as new therapeutic option for ChAc patients
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