Colonic Biopsies to Assess the Neuropathology of Parkinson's Disease and Its Relationship with Symptoms

The presence of Lewy bodies and Lewy neurites (LN) has been demonstrated in the enteric nervous system (ENS) of Parkinson's disease (PD) patients. The aims of the present research were to use routine colonoscopy biopsies (1) to analyze, in depth, enteric pathology throughout the colonic submucosal plexus (SMP), and (2) to correlate the pathological burden with neurological and gastrointestinal (GI) symptoms.A total of 10 control and 29 PD patients divided into 3 groups according to disease duration were included. PD and GI symptoms were assessed using the Unified Parkinson's Disease Rating Scale part III and the Rome III questionnaire, respectively. Four biopsies were taken from the ascending and descending colon during the course of a total colonoscopy. Immunohistochemical analysis was performed using antibodies against phosphorylated alpha-synuclein, neurofilaments NF 220 kDa (NF) and tyrosine hydroxylase (TH). The density of LN, labeled by anti-phosphorylated alpha-synuclein antibodies, was evaluated using a quantitative rating score. Lewy pathology was apparent in the colonic biopsies from 21 patients and in none of the controls. A decreased number of NF-immunoreactive neurons per ganglion was observed in the SMP of PD patients compared to controls. The amount of LN in the ENS was inversely correlated with neuronal count and positively correlated with levodopa-unresponsive features and constipation.Analysis of the ENS by routine colonoscopy biopsies is a useful tool for pre-mortem neuropathological diagnosis of PD, and also provides insight into the progression of motor and non-motor symptoms

Investigation of general and cytoskeletal markers to estimate numbers and proportions of neurons in the human intestine

An important requirement in pathological diagnostics in the human enteric nervous system (ENS) is the estimation of the total numbers of neurons and of proportions of distinct subpopulations. In this study, we compared the suitability of two suggested panneuronal markers, cuprolinic blue (CB) and anti-Hu-protein (HU), for staining and counting human myenteric neurons in wholemounts, derived from small and large intestinal samples. Furthermore, the proportional expression of three cytoskeletal intermediate filaments, a-internexin (IN), neurofilament 200 (NF) and peripherin (PE), was correlated with both CB and HU. In 8 CB- and HUstained wholemounts, 93.3% of all neurons were double labeled, 3.3% of neurons were stained only with CB whereas 3.3% were immuno-stained only for HU. Thus, both markers were comparably reliable in representing the putative total human myenteric neuron population in our material. The wholemounts double stained for IN/CB or IN/HU revealed between 56.2 and 71.5% of neurons to be IN-reactive. Between 42.8 and 50.9% of neurons were immunoreactive for NF whereas 53.9 to 62.4% of neurons were reactive for PE. Although our sample number was too small to allow final conclusions, we suggest that the variations in proportions of intermediate filament expression we observed may be due to individual circumstances rather than to correlation with age or region. The proportions of neurons positive for IN, NF or PE but unstained by CB histochemical or HU immunohistochemical techniques was between 0 and 2.2%. We conclude that both CB and HU techniques are suitable methods for representation of almost all myenteric neurons in the human gut and that the differential expression of the cytoskeletal proteins investigated has to be included in the classification of enteric neurons in pathological diagnostics of human gastrointestinal diseases

Correlated spin glass generated by structural disorder in the amorphous Dy6Fe74B20 alloy

Magnetic properties of the amorphous Dy-Fe-B alloy are studied in terms of the correlated-spin-glass approach of Chudnovsky et al.$-— Features predicted by the theory are clearly observed in the experiment. It is shown that the magnetization law may be presented in the form where it is determined by the dimensionless correlation function of structural disorder, C(y), only. The analysis of the magnetization curve allows one to distinguish between different models of disorder in amorphous solids. Experimental data on Dy-Fe-B are in favor of C=exp(-1/2 y 2 )