The Gallyas silver impregnation which is specific to neurofibrillary changes of paired helical filaments (PHF) and 15 nm straight filaments, was adapted to stain polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both PHF and tau polypeptides were readily and consistently stained by the Gallyas stain. This technique stained PHF greater than tau greater than high-molecular-weight microtubule-associated polypeptides (MAPS). Tubulin was stained only weakly. Neurofilament triplet, ubiquitin, bovine serum albumin and histones were unstained. The staining of PHF and tau polypeptides by Gallyas silver stain is consistent with the presence of tau in PHF.

Alzheimer Disease↗

PubMedDate not supplied

Morphological criteria for the recognition of Alzheimer's disease and the distribution pattern of cortical changes related to this disorder.

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Aged↗

PubMedDate not supplied

Staging of Alzheimer's disease-related neurofibrillary changes.

Specific immunocytochemical methods (AT8) permit evaluation of neuronal changes well before the actual formation of neurofibrillary tangles and neuropil threads. Initial changes are found in the transentorhinal region (temporal lobe). From here the destructive process encroaches upon the entorhinal region, Ammon's horn, and neocortex. Initial changes occur in comparatively young individuals and can also be observed at the same predilection sites in a few species of old aged domestic animals. In a later state of destruction, AT8 immunoreactive neurons develop typical argyrophilic neurofibrillary tangles and neuropil threads. Six stages of disease propagation can be distinguished with respect to the location of the tangle-bearing neurons and the severity of changes (transentorhinal stages I-II: clinically silent cases; limbic stages III-IV: incipient Alzheimer's disease; neocortical stages V-VI: fully developed Alzheimer's disease). Whole mount techniques reveal the lesional pattern of the particularly severely involved superficial entorhinal layer as seen from the free surface of the parahippocampal gyrus. This approach facilitates recognition of even subtle pathologic changes throughout the entire extent of cortical territories such as the transentorhinal and entorhinal regions.

Alzheimer Disease↗

PubMedDate not supplied

Age-related progression of tau pathology in brains of baboons.

Recently, cytoskeletal changes associated with abnormally phosphorylated tau protein were demonstrated in neurons and glial cells of two aged baboons (Papio). The present study examines the effects of age on the development of tau pathology in baboons. Brains of 50 baboons ranging in age from 1 to 30 years were categorized into four age groups: Group I: 1-10 years [n = 9], group II: 11-20 years [n = 13], group III: 21-25 years [n = 17], group IV: 26-30 years [n = 11]). Whole hemisphere sections (100 microm) were examined using phosphorylation-dependent anti-tau antibodies. Cytoskeletal changes were completely absent in animals of group I. In group II four animals (31%) exhibited cytoskeletal changes which were rated as mild or moderate. In group III abnormal tau was found in 12 brains (71%) ranging in severity from mild to severe. Finally, in group IV 10 out of 11 animals (91%) exhibited some degree of tau pathology which was rated as severe in 4 animals (36%). A statistically significant relationship was found between advancing age and progression of tau pathology in baboons. In conclusion, the present findings underline the value of the baboon as a potential nonhuman primate model for age-related tau pathology afflicting the human brain.

Aging↗

PubMedDate not supplied

Expression of stress proteins alpha B-crystallin, ubiquitin, and hsp27 in pallido-nigral spheroids of aged rhesus monkeys.

Ubiquitin and alpha B-crystallin belong to a class of proteins which are overexpressed in a variety of human neuropathological conditions associated with increased cellular stress. In this study we have examined the brains of aged rhesus monkeys (Macaca mulatta; n = 10, mean age: 29.7 years) using antibodies against the stress proteins ubiquitin, alpha B-crystallin, and heat shock protein 27 (hsp27). Here, we demonstrate an increased expression of ubiquitin, alpha B-crystallin, and hsp27 in spheroid bodies predominantly localized in the globus pallidus and pars reticulata of the substantia nigra. A portion of the pallido-nigral spheroids also contained ferric iron as highlighted by Perls' staining. On the basis of these findings we advance the hypothesis that expression of ubiquitin, alpha B-crystallin, and hsp27 in pallido-nigral spheroids of aged rhesus monkeys represents a stress response possibly related to increased iron-mediated oxidative stress.

Aging↗

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Parkinson's disease: the thalamic components of the limbic loop are severely impaired by alpha-synuclein immunopositive inclusion body pathology.

The Parkinson's disease (PD)-related inclusion body pathology comprises Lewy bodies (LBs) as well as Lewy neurites (LNs). The distribution and severity of this pathology were investigated in the thalamus of 12 autopsy cases with clinically diagnosed and neuropathologically confirmed PD. The LBs and LNs were visualized by immunoreactions against the protein alpha-synuclein. In the human thalamus during PD, a specific and highly stereotypical distribution pattern of LBs and LNs evolves. As in cortical and other subcortical regions, the components of human thalamus assigned to the limbic loop bear the brunt of the PD-related pathology. In contrast, the thalamic components integrated into the striatal and cerebellar loops as well as the primary sensory nuclei of the thalamus show at best a mildly developed pathology. Damage to the thalamic components of the limbic loop nuclei may contribute not only to the cognitive, emotional, and autonomic symptoms of PD but to the somatomotor and oculomotor dysfunctions as well.

Aged↗

PubMedDate not supplied

Frequency of stages of Alzheimer-related lesions in different age categories.

Alzheimer's disease is a relentlessly progressing dementing disorder. Major pathological hallmarks include extracellular deposits of amyloid protein and intraneuronal neurofibrillary changes. No remissions occur in the course of the disease. Initial amyloid deposits develop in poorly myelinated areas of the basal neocortex. From there, they spread into adjoining areas and the hippocampus. Deposits eventually infiltrate all cortical areas, including densely myelinated primary fields of the neocortex (stages A-C). Intraneuronal lesions develop initially in the transentorhinal region, then spread in a predictable manner across other areas (stages I-VI). At stages I-II, neurofibrillary changes develop preferentially in the absence of amyloid deposits. A proportion of cases shows early development of amyloid deposits and/or intraneuronal changes. Advanced age is thus not a prerequisite for the evolution of the lesions. Alzheimer's disease is an age-related, not an age-dependent disease. The degree of brain destruction at stages III-IV frequently leads to the appearance of initial clinical symptoms. The stages V-VI representing fully developed Alzheimer's disease are increasingly prevalent with increasing age. The arithmetic means of the stages of both the amyloid-depositing and the neurofibrillary pathology increase with age. Age is a risk factor for Alzheimer's disease.

Adult↗

PubMedDate not supplied

Diagnostic criteria for neuropathologic assessment of Alzheimer's disease.

Prior to any evaluation of morphologic brain changes, a decision must be made whether a given alteration is associated with aging or with disease. Patients with disease-related lesions may be in a clinically silent phase of a disease or show overt symptoms. Neurofibrillary tangles and neuropil threads are the hallmarks of Alzheimer's disease. They should not be considered to be age-related changes, even when they are present only in small numbers. In general, the initial changes consist of neurofibrillary tangles and neuropil threads. Plaques (amyloid deposits and/or neuritic plaques) are consistently present in the end stage of the disease. Initial neurofibrillary tangles and neuropil threads develop at specific cortical predilection sites. The changes then spread in a predictable, nonrandom manner across other portions of the telencephalic cortex. The sequential changes in the distribution pattern of the lesions provide the basis for a staging procedure that takes the slow and gradual progression of the destructive process into consideration. The staging procedure provides accurate diagnoses in the initial stages and even reveals brain changes developing prior to the appearance of clinical symptoms. It is thus advantageous in characterizing nondemented controls. The staging procedure can be carried out easily and does not require knowledge of clinical data, quantitative assessments, or adjustments for the age of the patients. Application of advanced silver techniques (Gallyas, Campbell-Switzer) to demonstrate Alzheimer's disease-related lesions also allows recognition of the hallmarks of other disorders, such as Lewy body disease (Parkinson's disease) and dementia with argyrophilic grains, which frequently co-occur with Alzheimer's disease.

Aged↗

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Pigment-filled appendages of the small spiny neurons: a severe pathological change of the striatum in neuronal ceroid lipofuscinosis.

In neuronal ceroid lipofuscinosis, the small spinous nerve cells of the striatum show a conspicuous pathological change in that they develop spindle-shaped and pigment-filled appendages of the soma. The axon emerges from the tip of these expansions, the volume of which often exceeds that of the cell body. The aspiny neurons of the striatum do not show this alteration. The pigment-filled expansions close to the axon may be considered an early sign of neuronal degeneration. The small spinous nerve cell is the predominant cell type of the striatum which receives inputs from various sources. Its slowly progressive destruction might account for extra-pyramidal motor disturbances in the course of neuronal ceroid lipofuscinosis.

Adolescent↗

PubMedDate not supplied

Neuropil threads occur in dendrites of tangle-bearing nerve cells.

Transparent Golgi preparations counterstained for Alzheimer's neurofibrillary changes rendered possible the demonstration of neuropil threads in defined cellular processes. Only dendrites of tangle-bearing cortical nerve cells were found to contain neuropil threads. Processes of glial cells as well as axons present in the material were devoid of neuropil threads.

Alzheimer Disease↗

PubMedDate not supplied

Cortical and subcortical argyrophilic grains characterize a disease associated with adult onset dementia.

Unusual cytoskeleton abnormalities were found in the brains of 28 individuals afflicted with adult onset dementia. Most conspicuous were small spindle-shaped argyrophilic grains loosely scattered throughout the neuropil. Additionally, coiled bodies of silver-stained filaments were encountered, mainly located within the white matter close to the cortical grey matter. Argyrophilic grains and coiled bodies contained dense accumulations of straight filaments with a diameter of about 9 nm. The argyrophilic grains were found in abundance within sector CA1 of the Ammon's horn and layer Pre-beta of the entorhinal region. A slightly less dense scattering of the grains occurred in layer IIIab of the adjoining temporal isocortex, insular cortex and orbitofrontal cortex. The basolateral amygdaloid complex and the hypothalamic lateral tuberal nucleus were the most affected subcortical structures. Deeper brain stem nuclei merely showed a sparse number of grains or were devoid of them. Eighty brains of demented individuals were examined. Forty-eight of them showed the features of Alzheimer's disease and four showed the features of Pick's disease. Twenty-eight cases revealed the abnormalities under consideration. Ten showed exclusively argyrophilic grains and coiled bodies, while 16 also had neuritic plaques, neurofibrillary tangles, and neuropil threads. One of the 28 cases was associated with Parkinson's disease and one showed features of both Parkinson's and Alzheimer's disease. Twenty brains of non-demented individuals of about the same age and devoid or almost devoid of Alzheimer changes were used as controls. None of the control brains showed the presence of argyrophilic grains and coiled bodies. These changes, therefore, are considered the morphological substrate of an unknown disease associated with adult onset dementia.

Aged↗

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Assessment of the pathological stages of Alzheimer's disease in thin paraffin sections: a comparative study.

The staging method proposed by Braak and Braak allows the objective and reliable assessment of Alzheimer-related neurofibrillary pathology. Originally the method was designed for 100-microm thick sections. However, the use of thick sections proved to present difficulties in a routine neuropathology laboratory. In order to adapt the staging method for thin paraffin-embedded sections, we performed an inter- and intrarater study analysing the reliability of the staging method in thin sections. Statistical analysis of the data provided by six independent examiners in two rating sessions reveal kappa values of 0.6-0.8 for both the interrater and the intrarater reliability. The average rate of mistake of the examiners was rarely bigger than a half stage. We conclude that the adapted staging method in thin sections is strongly reliable and we recommend it for staging purposes in institutions where the preparation of thick sections would be difficult.

Alzheimer Disease↗

PubMedDate not supplied

Relationship between clinical and radiological diagnostic criteria for Alzheimer's disease and the extent of neuropathology as reflected by 'stages': a prospective study.

The distribution of pathology related to Alzheimer's disease (AD) is not uniform throughout the brain. Sites which have a predilection for the development of Alzheimer-type pathology are the limbic regions and neocortical association areas. The changes in these areas of the brain develop gradually, following a well-determined sequence that allows a pathological staging of the disease process. According to the staging hypothesis, the first pathological alterations develop in the transentorhinal and entorhinal regions. The neurofibrillary pathology then spreads into the hippocampus, but not until the final stages does it affect the neocortex. In this study we analyse the relationship between the pathological stages of AD, according ot the staging hypothesis, and the clinical diagnosis in a prospectively assessed patient group. Prediction of any given pathological stage from the clinical diagnosis was found to be poor. This may be partly due to the fact that additional pathologies can alter the clinical picture and severity of dementia in patients who are only in the initial stages of AD. Nevertheless, the NINCDS-ADRDA clinical criteria had a high sensitivity for detection of AD-related pathology: the 'probable AD' category included 22/38 (57.9%) of those in the late isocortical stage, while the 'possible AD' category included 19/23 (82.6%) of those in the limbic stage. Using proposed neuro-imaging protocols for improved identification of patients with AD-related pathology, we largely identified subjects in whom the extent of pathology had spread to the neocortex.

Aged↗