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Prodromal Stage (prodromal + stage)
Selected AbstractsLaminar xanthine oxidase, superoxide dismutase and catalase activities in the prodromal stage of black-walnut induced equine laminitisEQUINE VETERINARY JOURNAL, Issue 1 2007J. P. LOFTUS Summary Reasons for study: Xanthine oxidase (XO)-dependent production of superoxide anion and hydrogen peroxide, a characteristic of ischaemia-reperfusion injury, may contribute to the development of equine laminitis. Objective: To determine the levels of XO and antioxidant enzymes (catalase, superoxide dismutase [SOD]) in the digital laminae of normal horses (CON) and horses in the developmental stage of laminitis using the black walnut extract (BWE) model. Methods: Healthy horses (n = 12) were administered BWE (BWE group, n = 6), or water (CON group, n = 6) through a nasogastric tube. At the onset of leucopenia in the BWE-treated animals, all horses were anaesthetised, digital laminae and other samples collected rapidly and flash frozen, and the animals subjected to euthanasia. Extracts of the frozen tissues were assayed for the 2 conformational forms of xanthine: oxygen oxidoreductase (XOR), namely, xanthine dehydrogenase (XDH) and xanthine oxidase (XO), as well as the antioxidant enzymes, SOD and catalase. Results: Extracts of liver, lungs and skin, but not digital laminae, from either CON or BWE-treated horses had endogenous SOD, whereas all had endogenous XO and catalase. The levels of XDH, XO and catalase were similar in extracts of laminae from CON and BWE-treated horses as was the ratio of XDH to XO in extracts. Conclusions and potential relevance: The absence of increased XO activity suggest against the involvement of this reactive oxygen intermediate-generating system in the development of laminar pathology in BWE-treated horses. Conversely, the absence of SOD from extracts of equine digital laminae, but not other tissues, suggests that the equine digital laminae are highly susceptible to damage by superoxide anion, produced, for example, by emigrant inflammatory leucocytes. [source] New insights into the pathology of Parkinson's disease: does the peripheral autonomic system become central?EUROPEAN JOURNAL OF NEUROLOGY, Issue 2008A. Probst Recent studies in aged, neurologically unimpaired subjects have pointed to a specific induction site of the pathological process of Parkinson's disease (PD) in the region of the dorsal glossopharyngeus,vagus complex as well as in the anterior olfactory nucleus. From the lower brainstem, the disease process would then pursue an ascending course and involve more rostral brainstem areas, limbic structures, and eventually the cerebral cortex. One barrier to the acceptance of the caudal medullary structures as the induction site of PD pathology is that not all parts of the nervous system have been investigated for the presence of PD-associated lesions in cases of early asymptomatic PD. Using alpha-synuclein immunostaining, we investigated the brain, the sacral, and thoracic autonomic nuclei of the spinal cord as well as several components of the peripheral autonomic nervous system in a autopsy cohort of 98 neurologically unimpaired subjects aged 64 or more. Our data indicate that the autonomic nuclei of the spinal cord and the peripheral autonomic nervous system belong to the most constantly and earliest affected regions next to medullary structures and the olfactory nerves in neurologically unimpaired older individuals, thus providing a pathological basis for early premotor autonomic dysfunctions at a prodromal stage of PD. [source] Decreased levels of PSD95 and two associated proteins and increased levels of BCl2 and caspase 3 in hippocampus from subjects with amnestic mild cognitive impairment: Insights into their potential roles for loss of synapses and memory, accumulation of A,, and neurodegeneration in a prodromal stage of Alzheimer's diseaseJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2010Rukhsana Sultana Abstract Alzheimer's disease (AD) is the most common form of dementia and is pathologically characterized by senile plaques, neurofibrillary tangles, synaptic disruption and loss, and progressive neuronal deficits. The exact mechanism(s) of AD pathogenesis largely remain unknown. With advances in technology diagnosis of a pre-AD stage referred to as amnestic mild cognitive impairment (MCI) has become possible. Amnestic MCI is characterized clinically by memory deficit, but normal activities of daily living and no dementia. In the present study, compared to controls, we observed in hippocampus from subjects with MCI a significantly decreased level of PSD95, a key synaptic protein, and also decreased levels of two proteins associated with PSD95, the N-methyl-D-aspartate receptor, subunit 2A (NR2A) and the low-density lipoprotein receptor-1 (LRP1). PSD95 and NR2A are involved in long-term potentiation, a key component of memory formation, and LRP1 is involved in efflux of amyloid beta-peptide (1-42). A, (1-42) conceivably is critical to the pathogenesis of MCI and AD, including the oxidative stress under which brain in both conditions exist. The data obtained from the current study suggest a possible involvement of these proteins in synaptic alterations, apoptosis and consequent decrements in learning and memory associated with the progression of MCI to AD. © 2009 Wiley-Liss, Inc. [source] The role of neuroimaging in mild cognitive impairmentNEUROPATHOLOGY, Issue 6 2007Hiroshi Matsuda The main purposes of neuroimaging in Alzheimer's disease (AD) have been moved from diagnosis of advanced AD to diagnosis of very early AD at a prodromal stage of mild cognitive impairment, prediction of conversion from mild cognitive impairment (MCI) to AD, and differential diagnosis from other diseases causing dementia. Structural MRI studies and functional studies using F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) and brain perfusion single-photon emission computed tomography (SPECT) are widely used in diagnosis of AD. Outstanding progress in diagnostic accuracy of these neuroimaging modalities has been obtained using statistical analysis on a voxel-by-voxel basis after spatial normalization of individual scans to a standardized brain-volume template instead of visual inspection or a conventional region of interest technique. In a very early stage of AD, this statistical approach revealed gray matter loss in the entorhinal and hippocampal areas and hypometabolism or hypoperfusion in the posterior cingulate cortex and precuneus. These two findings might be related in view of anatomical knowledge that the regions are linked through the circuit of Papez. This statistical approach also offers prediction of conversion from MCI to AD. Presence of hypometabolism or hypoperfusion in parietal association areas and entorhinal atrophy at the MCI stage has been reported to predict rapid conversion to AD. [source] | ||||||||||