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Racette, B. A., L. McGee-Minnich, et al. (2001).
"Welding-related parkinsonism: clinical features, treatment, and pathophysiology."
Neurology 56(1): 8-13.
OBJECTIVE: To determine whether welding-related parkinsonism differs from
idiopathic PD. BACKGROUND: Welding is considered a cause of parkinsonism, but
little information is available about the clinical features exhibited by
patients or whether this is a distinct disorder. METHODS: The authors performed
a case-control study that compared the clinical features of 15 career welders,
who were ascertained through an academic movement disorders center and compared
to two control groups with idiopathic PD. One control group was ascertained
sequentially to compare the frequency of clinical features, and the second
control group was sex- and age-matched to compare the frequency of motor
fluctuations. RESULTS: Welders were exposed to a mean of 47,144 welding hours.
Welders had a younger age at onset (46 years) of PD compared with sequentially
ascertained controls (63 years; p < 0.0001). There was no difference in
frequency of tremor, bradykinesia, rigidity, asymmetric onset, postural
instability, family history, clinical depression, dementia, or drug-induced
psychosis between the welders and the two control groups. All treated welders
responded to levodopa. Motor fluctuations and dyskinesias occurred at a similar
frequency in welders and the two control groups. PET with 6-[18F]fluorodopa
obtained in two of the welders showed findings typical of idiopathic PD, with
greatest loss in posterior putamen. CONCLUSIONS: Parkinsonism in welders is
distinguished clinically only by age at onset, suggesting welding may be a risk
factor for PD. These preliminary data cannot exclude a genetic contribution to
susceptibility in these exposed individuals.
Rajagopalan, S. and J. K. Andersen (2001). "Alpha synuclein aggregation: is it
the toxic gain of function responsible for neurodegeneration in Parkinson's
disease?" Mech Ageing Dev 122(14): 1499-510.
Protein aggregation appears to be the common denominator in a series of distinct
neurodegenerative diseases yet its role in the associated neuronal pathology in
these various conditions remains elusive. In Parkinson's disease, localization
of alpha synuclein aggregates within intracellular Lewy body occlusions
represent a major hallmark of this disorder and suggest that such aggregation
may play a causative role in the resulting dopaminergic cell loss. In this
Viewpoint article, recent data is reviewed related to how alpha synuclein
aggregation may occur, what cellular events might be responsible, and how this
may interfere with normal cellular function(s). It appears likely that while
aggregation of alpha synuclein may interfere with its normal function in the
cell, this is not the primary cause of the related neurodegeneration.
Rathke-Hartlieb, S., P. J. Kahle, et al. (2001). "Sensitivity to MPTP is not
increased in Parkinson's disease-associated mutant alpha-synuclein transgenic
mice." J Neurochem 77(4): 1181-4.
Environmental and genetic factors that contribute to the pathogenesis of
Parkinson's disease are discussed. Mutations in the alpha-synuclein (alphaSYN )
gene are associated with rare cases of autosomal-dominant Parkinson's disease.
We have analysed the dopaminergic system in transgenic mouse lines that
expressed mutant [A30P]alphaSYN under the control of a neurone-specific Thy-1 or
a tyrosine hydroxylase (TH) promoter. The latter mice showed somal and neuritic
accumulation of transgenic [A30P]alphaSYN in TH-positive neurones in the
substantia nigra. However, there was no difference in the number of TH-positive
neurones in the substantia nigra and the concentrations of catecholamines in the
striatum between these transgenic mice and non-transgenic littermates. To
investigate whether forced expression of [A30P]alphaSYN increased the
sensitivity to putative environmental factors we subjected transgenic mice to a
chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) regimen. The MPTP-induced
decrease in the number of TH-positive neurones in the substantia nigra and the
concentrations of catecholamines in the striatum did not differ in any of the
[A30P]alphaSYN transgenic mouse lines compared with wild-type controls. These
results suggest that mutations and forced expression of alphaSYN are not likely
to increase the susceptibility to environmental toxins in vivo.
Reid, A. H., S. McCall, et al. (2001). "Experimenting on the past: the enigma of
von Economo's encephalitis lethargica." J Neuropathol Exp Neurol 60(7):
663-70.
Encephalitis lethargica (EL) was a complex and mysterious disease that appeared
around the same time as the great influenza pandemic of 1918. The
contemporaneous relationship of the 2 diseases led to speculation that they were
causally related. Contemporary and subsequent observers conjectured that the
influenza virus, directly responsible for the deaths of more than 20 million
people, might also have been the cause of EL. A review of the extensive
literature by observers of the EL epidemic suggests that most contemporary
clinicians, epidemiologists, and pathologists rejected the theory that the 1918
influenza virus was directly responsible for EL. Disappearance of the acute form
of EL during the 1920s has precluded direct study of this entity. However,
modern molecular biology techniques have made it possible to examine archival
tissue samples from victims of the 1918 pandemic in order to detect and study
the genetic structure of the killer virus. Similarly, tissue samples from EL
victims can now be examined for evidence of infection by the 1918 influenza
virus.
Reilly, C. E. (2001). "Glial cell line-derived neurotrophic factor (GDNF)
prevents neurodegeneration in models of Parkinson's disease." J Neurol
248(1): 76-8.
Ruse, C. E. and S. G. Parker (2001). "Molecular genetics and age-related
disease." Age Ageing 30(6): 449-454.
Maintenance and repair processes are crucial to the pathogenesis of ageing and
late-onset disease. Thus, there is increasing recognition of the importance of
genetic factors in the development of late-onset conditions such as stroke,
Parkinson's disease and osteoporosis, and accumulating evidence for a genetic
component in the development of chronic obstructive pulmonary disease. We review
the approaches and problems in the genetic investigation of complex disorders in
old age, taking chronic obstructive pulmonary disease as an example.
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