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Lewy bodies and neurites, the pathological hallmarks found in the brain of Parkinson’s disease (PD) patients, are primarily composed of aggregated and hyperphosphorylated alpha-synuclein. The observation that alpha-synuclein inclusions are also found in the gut of the vast majority of parkinsonian patients has led to an increasing number of studies aimed at developing diagnostic procedures based on the detection of pathological alpha-synuclein in gastrointestinal biopsies. The previous studies, which have all used immunohistochemistry for the detection of alpha-synuclein, have provided conflicting results. In the current survey, we used a different approach by analyzing the immunoreactivity pattern of alpha-synuclein separated by one- and two-dimensional electrophoresis, in colonic biopsies from PD subjects and healthy individuals. We did not observe any differences between controls and PD in the expression levels, phosphorylation or aggregation status of alpha-synuclein. Overall, our study suggests that the two biochemical methods tested here are not adequate for the prediction of PD using gastrointestinal biopsies. Further studies, using other biochemical approaches, are warranted to test whether there exists specific forms of pathological alpha-synuclein that distinguish PD from control subjects. [ABSTRACT FROM AUTHOR]

Background: Alpha-synuclein containing inclusions in neurons, the characteristic pathological lesions of Parkinson's disease (PD), are not limited to the central nervous system, but also affect the enteric nervous system (ENS). This suggests that the ENS offer some potential as a surrogate of central nervous system pathology and that it may represent an original source of biomarkers for PD. However, the usefulness of α-synuclein detection in gastrointestinal biopsies as a biomarker for PD is still unclear, as the different immunohistochemical methods employed to date have led to conflicting results. Objective: Our aim is to propose an optimized immunoblotting method for the detection of endogenous α-synuclein in the healthy ENS that may be used to supplement the immunohistochemical analysis. Methods: Primary culture of rat ENS and homogenates of human small intestine were analyzed by Western Blot using seven different α-synuclein and phospho-α-synuclein antibodies along with two methods that increase α-synuclein retention on blot membranes, namely incubation of the membranes with paraformaldehyde (PFA) or treatment of samples with the crosslinker dithiobis[succinimidylpropionate] (DSP). Results: A moderate improvement in the detection of endogenous enteric α-synuclein was observed following membrane fixation with PFA for only two of the seven antibodies we tested. Immunodetection of total and phosphorylated α-synuclein in the ENS was markedly improved when samples were treated with DSP, regardless of the antibody used. Conclusions: Our results demonstrate that the detection of α-synuclein in the gut by Western Blot can be optimized by using methods for enhanced membrane retention of the protein along with the appropriate antibody. Such an optimized protocol opens the way to the development of novel biomarkers for PD that will enable a quantification of α-synuclein in gastrointestinal biopsies. [ABSTRACT FROM AUTHOR]

Objective: Whether bridging therapy (intravenous thrombolysis [IVT] followed by endovascular treatment) is superior to IVT alone in minor stroke with large vessel occlusion (LVO) is unknown.Methods: Multicentric retrospective observational study including, in intention-to-treat, consecutive IVT-treated minor strokes (National Institutes of Health Stroke Scale [NIHSS] ≤ 5) with LVO, with or without additional mechanical thrombectomy. Propensity-score (inverse probability of treatment weighting) was used to reduce baseline between-groups differences. The primary outcome was excellent outcome, that is, modified Rankin score 0 to 1 at 3 months follow-up.Results: Overall, 598 patients were included (214 and 384 in the bridging therapy and IVT groups, respectively). Following propensity-score weighting, the distribution of baseline clinical and radiological variables was similar across the two patient groups. Compared with IVT alone, bridging therapy was not associated with excellent outcome (odds ratio [OR] = 0.96; 95% confidence interval [CI] = 0.75-1.24; p = 0.76), but was associated with symptomatic intracranial hemorrhage (OR = 3.01; 95% CI = 1.77-5.11; p < 0.0001). Occlusion site was a strong modifier of the effect of bridging therapy on outcome (pinteraction < 0.0001), with bridging therapy associated with higher odds of excellent outcome in proximal M1 (OR = 3.26; 95% CI = 1.67-6.35; p = 0.0006) and distal M1 (OR = 1.69; 95% CI = 1.01-2.82; p = 0.04) occlusions, but with lower odds of excellent outcome for M2 (OR = 0.53; 95% CI = 0.38-0.75; p = 0.0003) occlusions. Bridging therapy was associated with higher rates of symptomatic intracranial hemorrhage in M2 occlusions only (OR = 4.40; 95% CI = 2.20-8.83; p < 0.0001).Interpretation: Although overall outcomes were similar in intended bridging therapy as compared to intended IVT alone in minor strokes with LVO, our results suggest that intended bridging therapy may be beneficial in M1 occlusions, whereas the benefit-risk profile may favor IVT alone in M2 occlusions. ANN NEUROL 2020 ANN NEUROL 2020;88:160-169. [ABSTRACT FROM AUTHOR]