138 research outputs found

    Polyphenol oxidases exhibit promiscuous proteolytic activity

    Get PDF
    Tyrosinases are an industrially significant class of polyphenol oxidase. Here, two tyrosinases are shown to cleave a specific peptide bond in a carboxylesterase, yielding a truncated product with higher catalytic activity than the full-length enzyme

    Deep brain stimulation of globus pallidus internus and subthalamic nucleus in Parkinson’s disease: a multicenter, retrospective study of efficacy and safety

    Get PDF
    BackgroundDeep brain stimulation (DBS) is an established therapeutic option in advanced Parkinson's disease (PD). Literature data and recent guidelines remain inconclusive about the best choice as a target between the subthalamic nucleus (STN) and the globus pallidus internus (GPi).Materials and methodsWe retrospectively reviewed the clinical efficacy outcomes of 48 DBS-implanted patients (33 STN-DBS and 15 GPi-DBS) at a short- (<1 year from the surgery) and long-term (2-5 years) follow-up. Also, clinical safety outcomes, including postoperative surgical complications and severe side effects, were collected.ResultsWe found no difference between STN-DBS and GPi-DBS in improving motor symptoms at short-term evaluation. However, STN-DBS achieved a more prominent reduction in oral therapy (l-dopa equivalent daily dose, P = .02). By contrast, GPi-DBS was superior in ameliorating motor fluctuations and dyskinesia (MDS-UPDRS IV, P < .001) as well as motor experiences of daily living (MDS-UPDRS II, P = .03). The greater efficacy of GPi-DBS on motor fluctuations and experiences of daily living was also present at the long-term follow-up. We observed five serious adverse events, including two suicides, all among STN-DBS patients.ConclusionBoth STN-DBS and GPi-DBS are effective in improving motor symptoms severity and complications, but GPi-DBS has a greater impact on motor fluctuations and motor experiences of daily living. These results suggest that the two targets should be considered equivalent in motor efficacy, with GPi-DBS as a valuable option in patients with prominent motor complications. The occurrence of suicides in STN-treated patients claims further attention in target selection

    Cortical thickness, surface area and volume measures in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy

    Get PDF
    OBJECTIVE Parkinson's disease (PD), Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) are neurodegenerative diseases that can be difficult to distinguish clinically. The objective of the current study was to use surface-based analysis techniques to assess cortical thickness, surface area and grey matter volume to identify unique morphological patterns of cortical atrophy in PD, MSA and PSP and to relate these patterns of change to disease duration and clinical features. METHODS High resolution 3D T1-weighted MRI volumes were acquired from 14 PD patients, 18 MSA, 14 PSP and 19 healthy control participants. Cortical thickness, surface area and volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.1.0). Measures of disease severity and duration were assessed for correlation with cortical morphometric changes in each clinical group. RESULTS Results show that in PSP, widespread cortical thinning and volume loss occurs within the frontal lobe, particularly the superior frontal gyrus. In addition, PSP patients also displayed increased surface area in the pericalcarine. In comparison, PD and MSA did not display significant changes in cortical morphology. CONCLUSION These results demonstrate that patients with clinically established PSP exhibit distinct patterns of cortical atrophy, particularly affecting the frontal lobe. These results could be used in the future to develop a useful clinical application of MRI to distinguish PSP patients from PD and MSA patients

    A single-center experience on below-the-knee endovascular treatment in diabetic patients

    Get PDF
    Diabetic ulceration of the foot is a major global medical, social and economic problem and is the most frequent end-point of diabetic complications. A retrospective analysis from February 2017 to May 2019 of diabetic patients presenting below-the-knee artery disease (PAD) was carried out. Only patients treated with endovascular techniques as first choice treatment were evaluated. Outcome measured was perioperative mortality and morbidity. Freedom from occlusion, secondary patency and amputation rate were all registered. Additional maneuvers including stenting or angioplasty with drug eluting balloon (DEB) were reported. A total of 167 (101 male/66 female) patients with a mean age of 71 years were included in the study. A Rutherford 3, 4, 5 and 6 categories were reported in 5, 7, 110 and 45 patients, respectively. No perioperative mortality was reported. Morbidity occurred in 4 (4.4%) cases and consisted of pseudoaneurysm. Additional stenting during first procedure was required in 7 (4%) patients, drug eluting balloon was needed in 56 (33%) patients. At 1-year follow-up, estimated freedom from occlusion and secondary patency was 70% and 80% respectively. Major amputation rate was 2.4%, minor amputation rate was 41.9%. In our experience, extreme revascularization in search of distal direct flow reduce the rate of amputations with an increase in ulcer healing. New materials and techniques such as drug eluting technology, used properly, can improve outcome

    Development and Validation of Automated Magnetic Resonance Parkinsonism Index 2.0 to Distinguish Progressive Supranuclear Palsy-Parkinsonism From Parkinson's Disease

    Get PDF
    Background: Differentiating progressive supranuclear palsy-parkinsonism (PSP-P) from Parkinson's disease (PD) is clinically challenging. Objective: This study aimed to develop an automated Magnetic Resonance Parkinsonism Index 2.0 (MRPI 2.0) algorithm to distinguish PSP-P from PD and to validate its diagnostic performance in two large independent cohorts. Methods: We enrolled 676 participants: a training cohort (n&nbsp;=&nbsp;346; 43 PSP-P, 194 PD, and 109 control subjects) from our center and an independent testing cohort (n&nbsp;=&nbsp;330; 62 PSP-P, 171 PD, and 97 control subjects) from an international research group. We developed a new in-house algorithm for MRPI 2.0 calculation and assessed its performance in distinguishing PSP-P from PD and control subjects in both cohorts using receiver operating characteristic curves. Results: The automated MRPI 2.0 showed excellent performance in differentiating patients with PSP-P from patients with PD and control subjects both in the training cohort (area under the receiver operating characteristic curve [AUC]&nbsp;=&nbsp;0.93 [95% confidence interval, 0.89–0.98] and AUC&nbsp;=&nbsp;0.97 [0.93–1.00], respectively) and in the international testing cohort (PSP-P versus PD, AUC&nbsp;=&nbsp;0.92 [0.87–0.97]; PSP-P versus controls, AUC&nbsp;=&nbsp;0.94 [0.90–0.98]), suggesting the generalizability of the results. The automated MRPI 2.0 also accurately distinguished between PSP-P and PD in the early stage of the diseases (AUC&nbsp;=&nbsp;0.91 [0.84–0.97]). A strong correlation (r&nbsp;=&nbsp;0.91, P &lt; 0.001) was found between automated and manual MRPI 2.0 values. Conclusions: Our study provides an automated, validated, and generalizable magnetic resonance biomarker to distinguish PSP-P from PD. The use of the automated MRPI 2.0 algorithm rather than manual measurements could be important to standardize measures in patients with PSP-P across centers, with a positive impact on multicenter studies and clinical trials involving patients from different geographic regions. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

    Dual Effect of Beta-Amyloid on α7 and α4β2 Nicotinic Receptors Controlling the Release of Glutamate, Aspartate and GABA in Rat Hippocampus

    Get PDF
    BACKGROUND: We previously showed that beta-amyloid (Aβ), a peptide considered as relevant to Alzheimer's Disease, is able to act as a neuromodulator affecting neurotransmitter release in absence of evident sign of neurotoxicity in two different rat brain areas. In this paper we focused on the hippocampus, a brain area which is sensitive to Alzheimer's Disease pathology, evaluating the effect of Aβ (at different concentrations) on the neurotransmitter release stimulated by the activation of pre-synaptic cholinergic nicotinic receptors (nAChRs, α4β2 and α7 subtypes). Particularly, we focused on some neurotransmitters that are usually involved in learning and memory: glutamate, aspartate and GABA. METHODOLOGY/FINDINGS: WE USED A DUAL APPROACH: in vivo experiments (microdialysis technique on freely moving rats) in parallel to in vitro experiments (isolated nerve endings derived from rat hippocampus). Both in vivo and in vitro the administration of nicotine stimulated an overflow of aspartate, glutamate and GABA. This effect was greatly inhibited by the highest concentrations of Aβ considered (10 µM in vivo and 100 nM in vitro). In vivo administration of 100 nM Aβ (the lowest concentration considered) potentiated the GABA overflow evoked by nicotine. All these effects were specific for Aβ and for nicotinic secretory stimuli. The in vitro administration of either choline or 5-Iodo-A-85380 dihydrochloride (α7 and α4β2 nAChRs selective agonists, respectively) elicited the hippocampal release of aspartate, glutamate, and GABA. High Aβ concentrations (100 nM) inhibited the overflow of all three neurotransmitters evoked by both choline and 5-Iodo-A-85380 dihydrochloride. On the contrary, low Aβ concentrations (1 nM and 100 pM) selectively acted on α7 subtypes potentiating the choline-induced release of both aspartate and glutamate, but not the one of GABA. CONCLUSIONS/SIGNIFICANCE: The results reinforce the concept that Aβ has relevant neuromodulatory effects, which may span from facilitation to inhibition of stimulated release depending upon the concentration used
    • …
    corecore