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At least 109 records · Page 6Linked to original sources
PubMed1983

Neuron loss in the nucleus basalis of Meynert in parkinsonism-dementia complex of Guam.

The nucleus basalis of Meynert, which supplies diffuse cholinergic fibers to the cerebral neocortex, was investigated in two cases of parkinsonism-dementia complex of Guam (PDG). The nucleus basalis of the two PDG patients showed extensive neuron loss when compared with age-matched non-Guamanian controls, suggesting the necessity of investigating activity of cholinergic enzymes in the brains of patients with PDG.

Brain↗
PubMed1990

Immunohistochemical study of the striatal efferents and nigral dopaminergic neurons in parkinsonism-dementia complex on Guam in comparison with those in Parkinson's and Alzheimer's diseases.

A comparative topographical immunohistochemical analysis was performed on the basal ganglia (including the substantia nigra) in Guamanian parkinsonism-dementia complex, idiopathic Parkinson's disease (PD), and Alzheimer's disease (AD). The striatal projection neurons and their efferent fibers were examined by using antibodies to calcineurin, methionine-enkephalin, and substance P. Tyrosine hydroxylase served as a marker for nigrostriatal dopaminergic neurons. The basal ganglia of patients with parkinsonism-dementia complex reacted strongly with all of the antibodies and the reaction products exhibited a normal distribution pattern. These findings suggest that the striatal output system is well preserved in patients with this disease. Similar results were obtained in patients with AD or PD. However, as compared to the patients with AD or PD, patients with parkinsonism-dementia complex showed severe reduction (greater than 90%) in the number of dopaminergic neurons in both the lateral and the medial portions of the substantia nigra. In view of the functional cortico-subcortical loops, these findings could explain the parkinsonian features and in part the cognitive impairment that occur in parkinsonism-dementia complex on Guam.

Alzheimer Disease↗
PubMed1999

The Guam cycad toxin methylazoxymethanol damages neuronal DNA and modulates tau mRNA expression and excitotoxicity.

As in Alzheimer's disease, brains of Guam Chamorros with amyotrophic lateral sclerosis (ALS) and Parkinsonism-dementia complex (PDC) contain intraneuronal-paired helical filaments composed of accumulated phosphorylated tau protein. Tau mRNA expression in rat neuronal cultures-normally modulated by glutamate-increases after treatment with the aglycone of cycasin, a cycad-derived toxin whose concentration in Chamorro food varies with disease incidence. Elevated Tau gene expression in vitro is coincident with increased cycasin-related DNA adducts and reduced DNA repair. Cycasin and endogenous glutamate may together promote the accumulation of tau protein and neuronal degeneration in Western Pacific ALS/PDC.

Animals↗
PubMed1994

Demonstration of neurofibrillary tangles and neuropil thread-like structures in spinal cord white matter in parkinsonism-dementia complex on Guam and in Guamanian amyotrophic lateral sclerosis.

This report concerns the demonstration and distribution of neurofibrillary tangles (NFTs), immunoreactive neuropil thread-like structures and dots in the spinal cord gray and white matter of six patients with parkinsonism-dementia complex on Guam and five patients with Guamanian amyotrophic lateral sclerosis (ALS). A monoclonal antibody to Alzheimer NFTs was used. NFTs were found in the spinal cord gray matter and white matter and all patients had immunoreactive neuropil thread-like structures and dots in the gray matter as well as in the white matter. They were particularly numerous in the lateral funiculus of patients with Guamanian ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1990

Neuronal inputs to hippocampal formation in Alzheimer's disease and in parkinsonism-dementia complex on Guam.

This study concerns the expression of synaptophysin in the hippocampal formation of normal controls, of patients with Alzheimer's disease (AD) and of patients with parkinsonism-dementia complex on Guam (P-D complex). A monoclonal antibody was used to visualize synaptophysin, an integral component of presynaptic vesicle membranes. In the normal controls, a strong synaptophysin immunoreactivity was seen in the stratum pyramidale, stratum radiatum and stratum lacunosum-moleculare of the hippocampus proper, in the subiculum and in the molecular layer of the dentate gyrus. In the dentate gyrus molecular layer, the reaction product was distributed in a laminar fashion. By contrast, in AD and in P-D complex a significant decrease in immunoreactivity was observed in all hippocampal strata, and especially of the hippocampal subfield CA1 and the subiculum. In both diseases, synaptophysin expression was also diminished in the molecular layer of the dentate gyrus of all patients examined, with the inner portion exhibiting almost normal and the outer portion a strikingly reduced synaptophysin immunoreactivity.

Adult↗
PubMed1992

Ultrastructural identification of neurofibrillary tangles in the spinal cords in Guamanian amyotrophic lateral sclerosis and parkinsonism-dementia complex on Guam.

The immunohistochemical and ultrastructural characteristics of spinal cord neurofibrillary tangles (NFTs) were examined in Guamanian amyotrophic lateral sclerosis and in parkinisonism-dementia complex on Guam. The spinal cord NFTs reacted with antibodies to tau protein (tau-2), ubiquitin and paired helical filaments (PHFs). Ultrastructurally, the components of the NFTs were seen as randomly arranged fibrils which were often associated with osmiophilic granules; small bundle-like arrangements were also occasionally observed. Individual NFT fibrils appeared as straight fibrils with a diameter of approximately 15 nm and constricted fibrils with a periodicity of approximately 80 nm. Ultrastructural microscopic examination of specimens stained by the modified Bielschowsky method and with the antibodies revealed silver particles and the products of the tau, ubiquitin and PHF immunoreactions on the NFT fibrils. This is the first demonstration of the fine structure of the spinal cord NFTs.

Adult↗
PubMed1993

Striosomal arrangement of met-enkephalin and substance P expression in parkinsonism-dementia complex on Guam.

This report concerns a topographic immunohistochemical analysis of Met-enkephalin (MEnk) and substance P (SP) expression in the striatum from seven patients with parkinsonism-dementia complex on Guam (PDC). The striatum of seven neurologically normal subjects served as controls. MEnk-positive striosomes were readily visualized in both the caudate nucleus and the putamen of the PDC cases. Although the immunoreactivity was less than that of MEnk, SP-positive patches were detected in the PDC striatum. The patches were similar to those seen in the normal controls. These results provide additional evidence that the striatum and its efferent system appear to be preserved in patients with PDC.

Corpus Striatum↗
PubMed1994

Amyotrophic lateral sclerosis/parkinsonism-dementia complex of Guam: quantitative neuropathology, immunohistochemical analysis of neuronal vulnerability, and comparison with related neurodegenerative disorders.

Amyotrophic lateral sclerosis/parkinsonism-dementia complex (lytico-bodig) is a chronic neurodegenerative disorder with high prevalence among the native Chamorro population of Guam. Neuropathological, biochemical, and immunohistochemical analyses were performed on a relatively large series of Guamanian cases and compared to Alzheimer's disease cases. Thioflavin S and antibodies to amyloid beta A4 and tau proteins were used for analysis of pathological changes, and antibodies to the calcium-binding proteins parvalbumin and calretinin, and to a nonphosphorylated epitope on neurofilament protein to study select neuronal populations. A differential distribution of neurofibrillary tangles was observed in the neocortex of Guamanian cases compared to Alzheimer's disease cases, with much higher lesion counts in supragranular than in infragranular layers. Also, Guamanian cases with predominant parkinsonism had generally higher neurofibrillary tangle densities than cases with predominant amyotrophic lateral sclerosis. In addition, there was a certain degree of heterogeneity, qualitatively and quantitatively, in the biochemical distribution of tau proteins among Guamanian and Alzheimer's disease cases as revealed by Western blot analysis. Previous studies have suggested that the clinical symptomatology observed in patients suffering from Alzheimer's disease is related to the dramatic loss of specific corticocortically projecting neurons in the neocortex. Interestingly, a subset of neurofilament-rich pyramidal neurons known to be dramatically affected in Alzheimer's disease appears to be resistant in lytico-bodig. Finally, as in Alzheimer's disease, calcium-binding protein-containing interneurons are not affected. These data suggest that the set of projection neurons affected in Guamanian cases may not correspond to those involved in Alzheimer's disease, and that both disorders are characterized by specific patterns of neuronal vulnerability.

Adult↗
PubMed1985

Nucleus raphe dorsalis in parkinsonism-dementia complex of Guam.

Recently, morphometric analysis has shown that the nucleus raphe dorsalis, which is presumed to project diffuse serotonergic fibers to the telencephalon, is affected in Alzheimer's disease. A similar study was conducted in this report in two patients with parkinsonism-dementia complex of Guam and a Guamanian control. It demonstrated a significant reduction in the number of large neurons, and the presence of abundant Alzheimer's neurofibrillary tangles in this nucleus.

Cell Count↗
PubMed1988

Histochemical and X-ray microanalytical localization of aluminum in amyotrophic lateral sclerosis and parkinsonism-dementia of Guam.

Histochemical staining for aluminum, using Solochrome azurine or Morin, provided a rapid, simple and reliable means of identifying areas and structures of the brain of interest for closer scrutiny by X-ray microanalysis in patients with amyotrophic lateral sclerosis and parkinsonism-dementia of Guam. Neuronal perikarya, dendritic processes, and the walls of some cerebral vessels were aluminum positive by Solochrome azurine staining. In some cases, the deposition of aluminum was rather diffuse, particularly in the white matter. Fluorescent localization of aluminum using Morin was equally sensitive and specific, but provided less morphological detail than Solochrome azurine. Confirmation of histochemical detection of aluminum was achieved by examining adjacent tissue sections using wavelength-dispersive spectrometry coupled to a computer-controlled electron beam X-ray microprobe. Although the minimum detectable limits for aluminum by these histochemical procedures are unknown, the lower detection limit of our X-ray microanalytical technique is 10-100 ppm dry weight. Solochrome and Morin staining, as verified by X-ray microanalysis, afford a useful and reliable means of surveying multiple anatomical regions for aluminum deposition in naturally occurring and experimentally induced neurodegenerative disorders.

Adolescent↗
PubMed1993

Abnormal distribution of cathepsin proteinases and endogenous inhibitors (cystatins) in the hippocampus of patients with Alzheimer's disease, parkinsonism-dementia complex on Guam, and senile dementia and in the aged.

The immunolocalization of cathepsins B(CB), H and L and cystatins alpha(C alpha) and beta(C beta) were examined in the hippocampus of cases of sporadic Alzheimer's disease (12 cases), parkinsonism-dementia complex on Guam (eight cases), senile dementia of Alzheimer type (two cases), aged subjects with marked senile change (one case) and controls (12 cases, including six normal subjects). CB was lower in most nerve cells in patients than in controls, but markedly increased at the sites of intracellular neurofibrillary tangles (NFTs) and degenerative neurites and/or dendrites in and outside senile plaques (SPs), indicating its close involvement in the metabolisms of various proteins in NFT and SPs. Abundant C alpha and C beta were demonstrated in SP amyloid, suggesting that they are amyloid constituents or co-exist with amyloid. The present study indicated that CB, C alpha and C beta are closely involved in abnormal protein metabolism in NFTs and SP amyloid and suggested that degeneration or denaturation of intracellular proteins, including substrates for proteases and lysosomes, from some acquired cause, results in absolute and/or relative overload for these proteolytic systems, including their inhibitors. This results in incomplete and/or abnormal proteolysis related to NFT and/or amyloid formation.

Adult↗
PubMed1993

Sequencing of exons 16 and 17 of the beta-amyloid precursor protein gene reveals the beta-amyloid sequence to be normal in cases of the parkinson dementia complex of Guam.

Exons 16 and 17 of the beta-amyloid precursor protein gene has been sequenced in individuals with the amyotropic lateral sclerosis/Parkinson's dementia complex of Guam to test the hypothesis that this disease is an allelic variant of Alzheimer's disease and to test whether sequence differences within beta-amyloid in this population contributes to the non-deposition of this peptide in the disorder. The sequence was normal.

Aged↗
PubMed1996

Distinct distribution of apolipoprotein E and beta-amyloid immunoreactivity in the hippocampus of Parkinson dementia complex of Guam.

The distribution of apolipoprotein E (ApoE) was studied in the brain tissue of cases of the amyotrophic lateral sclerosis-parkinsonism-dementia complex of Guam, locally known as lytico bodig disease (LB), and compared with cases of Alzheimer's disease (AD) and normal brain tissue. In both LB and AD, strong ApoE immunostaining was observed in association with pathological lesions. In LB, these were mainly extracellular neurofibrillary tangles (eNFTs) which were intensely immuno-positive for ApoE. Occasional diffuse beta-amyloid protein (beta AP) deposits appear in this disorder and they were moderately immunopositive. In AD, senile plaques and diffuse beta AP deposits were intensely immunopositive, while eNFTs were only moderately immunopositive. The reason for the strong association of ApoE with the pathological entities in LB and AD is unknown, but may be related to a scavenger function which does not involve lipid metabolism. In both LB and AD, subpial and layer I diffuse deposits were ApoE negative but beta AP positive. Intracellular NFTs were mostly ApoE negative. A few showed weak positive staining. These data suggest that ApoE appears in LB and AD pathological lesions only after they are well established. In all controls, as well as all LB and AD cases, strong ApoE immunoreactivity was observed in unidentifiable structures in capillaries. Weak staining in a few neurons and very weak staining of an occasional astrocyte was observed. The source of ApoE which is deposited on extracellular pathological structures in LB and AD is unknown.

Adult↗
PubMed1997

Dystrophic neurites are associated with early stage extracellular neurofibrillary tangles in the parkinsonism-dementia complex of Guam.

We found tangle-associated neuritic clusters (TANCs), previously reported as being present in Alzheimer's disease (AD), to be common in early and mild cases of the parkinsonism-dementia complex of Guam (PDC, bodig disease). These entities were observed around extracellular neurofibrillary tangles (eNFTs), apparently as a transient phenomenon. They were not observed around normal neurons, or neurons with intracellular neurofibrillary tangles (iNFTs). They were also not observed around late stage eNFTs. The TANCs contained both type 1 (elongated) and type 2 (globular) dystrophic neurites, as well as small, granular structures. The type 1 dystrophic neurites in TANCs were immunostained by antibodies to neuroskeletal proteins, while type 2 dystrophic neurites were immunostained by antibodies to amyloid precursor protein (APP). The eNFTs surrounded by TANCs were almost all immunopositive for amyloid P, while only some were immunopositive for C4d, and only a minority had beta-amyloid protein (A beta) associated with them. We hypothesize that the eNFTs are a source of complement activation which results in destruction of surrounding neurites. We further hypothesize that the degenerating neurites are a source of A beta which forms long-term deposits around eNFTs.

Aged↗
PubMed1994

Amyotrophic lateral sclerosis and parkinsonism-dementia from Guam: differences in neurofibrillary tangle distribution and density in the hippocampal formation and neocortex.

Amyotrophic lateral sclerosis/parkinsonism-dementia complex is a highly prevalent neurodegenerative disorder among the native Chamorro population of Guam, and is characterized by widespread formation of neurofibrillary tangles. In the present study, the distribution of neurofibrillary tangles was quantitatively assessed in the cerebral cortex of cases presenting with either predominant amyotrophic lateral sclerosis or parkinsonism-dementia symptomatology. Results show that although the regional and laminar lesion distribution is qualitatively similar in both groups, cases with predominant parkinsonism-dementia generally have higher lesion densities than cases with amyotrophic lateral sclerosis. Interestingly, layer II of the entorhinal cortex was affected to the same degree in both conditions. In both groups, the CA1 field of the hippocampus, subiculum, and entorhinal cortex were the most affected areas. In the neocortex, the perirhinal and inferior temporal cortex consistently had higher lesion densities than the frontal, parietal, and cingulate cortex, whereas the visual cortex was practically devoid of lesions. Also, most of the neurofibrillary tangles were located in the supragranular layers of the neocortex, with relatively low densities in the infragranular layers, in both brain groups. Interestingly, the primary motor cortex contained more neurofibrillary tangles in parkinsonism-dementia than in amyotrophic lateral sclerosis cases. It is possible that the differences in regional neurofibrillary tangle densities reflect the variable severity of the dementing process observed between the two groups of patients. Several studies on Alzheimer's disease and related disorders indicate that the regional and laminar cortical localization of neurofibrillary tangles may parallel the degeneration of specific corticocortical projections. The present data suggest that the population of corticocortical projections involved in Guamanian cases differs substantially from that affected in Alzheimer's disease. The differential distribution and densities of the lesions may contribute to the differences in symptomatology and severity of dementia among Alzheimer's disease and Guamanian cases, although these neurodegenerative disorders as well as related illnesses may share certain etiopathogenetic mechanisms.

Adult↗
PubMed2004

Elevated levels of ferrimagnetic metals in foodchains supporting the Guam cluster of neurodegeneration: do metal nucleated crystal contaminants [corrected] evoke magnetic fields that initiate the progressive pathogenesis of neurodegeneration?

Elevated levels of aluminium (Al), strontium (Sr), barium (Ba), iron (Fe), manganese (Mn) cations - combined with deficiencies of magnesium (Mg)/calcium (Ca) - have been observed in the foodchains that traditionally support the Chamorro populations affected by high incidence clusters of Alzheimer (AD), Parkinson-like (PD), motor neurone diseases and multiple sclerosis on the island of Guam. Soils drawn from the cluster region demonstrated an excessive fivefold increase in 'magnetic susceptibility' readings in relation to soils from disease free adjoining regions. A multifactorial aetiological hypothesis is proposed that pivots upon the combined exposure to high levels of natural/industrial sources of ferrimagnetic/ferroelectric compounds incorporating Al, Fe, Mn, Sr, Ba (e.g., via yam/seafood consumption or exposure to world war 2 (WW2) munitions) and to low levels of Mg/Ca in all S. Pacific locations where these clusters of neurodegenerative disease have simultaneously erupted. Once gut/blood brain barrier permeability is impaired, the increased uptake of Al, Fe, Sr, Ba, or Mn into the Mg/Ca depleted brain leads to rogue metal substitutions at the Mg/Ca vacated binding domains on various enzyme/proteoglycan groups, causing a broad ranging disruption in Mg/Ca dependent systems - such as the glutamine synthetase which prevents the accumulation of neurotoxic glutamate. The rogue metals chelate sulphate, disrupting sulphated-proteoglycan mediated inhibition of crystal proliferation, as well as its regulation of the Fibroblast growth factor receptor complex which disturbs the molecular conformation of those receptors and their regulation of transphosphorylation between intracellular kinase domains; ultimately collapsing proteoglycan mediated cell-cell signalling pathways which maintain the growth and structural integrity of the neuronal networks. The depression of Mg/Ca dependent systems in conjunction with the progressive ferrimagnetisation of the CNS due to an overload of rogue ferroelectric/ferrimagnetic metal contaminants, enables 'seeding' of metal-protein crystalline arrays that can proliferate in the proteoglycan depleted brain. The resulting magnetic field emissions initiate a free radical mediated progressive pathogenesis of neurodegeneration. The co-clustering of these various types of disease in select geographical pockets around the world suggests that all of these conditions share a common early life exposure to ferromagnetic metal nucleating agents in their multifactorial aetiology. Factors such as individual genetics, the species of metal involved, etc., dictate which specific class of disease will emerge as a delayed neurotoxic response to these environmental insults.

Amyotrophic Lateral Sclerosis↗
PubMed2004

A human granin-like neuroendocrine peptide precursor (proSAAS) immunoreactivity in tau inclusions of Alzheimer's disease and parkinsonism-dementia complex on Guam.

The deposition of tau inclusions is one of the neuropathological hallmarks in neurodegenerative disorders with dementia. We have reported that the N-terminal fragment of a human granin-like neuroendocrine peptide precursor (N-proSAAS) is accumulated in Pick bodies. However, it is unknown whether N-proSAAS is widely accumulated in tau inclusions in other tauopathies. Here, we performed an immunohistochemical examination using antibodies against both the N- and C-terminal sequence of proSAAS in the brains of patients with Alzheimer's disease and parkinsonism-dementia complex on Guam. The antibody against N-proSAAS immunostained neurofibrillary tangles and neuritic plaques in both diseases, whereas the antibody against the C-terminal sequence of proSAAS did not. The results of the present study suggest that N-proSAAS or proSAAS-like molecules were trapped within the tau fibrils and accumulated in tau inclusions.

Aged↗
PubMed2006

Arsenic speciation study in some spring waters of Guam, Western Pacific Ocean.

A survey of the different forms of arsenic species: inorganic arsenic (As), As(III), As(V) and organic As(III) and (V) was carried out on spring waters located along Tumon Bay in Guam. The results show that total arsenic concentrations in the spring water samples ranged from <0.3-1.2 microg/L. Inorganic arsenate, As(V), appears to be the dominant species in the spring water samples tested. The concentrations are much lower than previously reported, probably due to a much more rigorous methodological approach and requires further investigations on the status of As contamination in groundwater on the island.

Arsenic↗