Reduction in asymmetrical dimethylarginine, an endogenous nitric oxide synthase inhibitor, in the cerebrospinal fluid during aging and in patients with Alzheimer's disease

To investigate the significance of nitric oxide (NO) -mediated neuron death in aging and Alzheimer's disease (AD), the concentration of asymmetrical dimethylarginine (ADMA), an endogenous NO synthase inhibitor, in the cerebrospinal fluid was determined in neurologically normal controls and patients with AD. The ADMA concentration significantly decreased with age, whereas the arginine concentration was unaltered. In patients with AD, the ADMA concentration was significantly decreased, compared with controls of a similar age (-48%, P=0.0001), and it significantly decreased with decreasing cognitive functions (r(s)=0.58, P<0.05), whereas the arginine concentration did not change. These findings suggest that ADMA may play an important role in regulating NO synthesis in brain aging and AD.

NKT-associated markers and perforin in hyperplastic thymuses from patients with Myasthenia gravis

Immunohistochemical expression of natural killer T (NKT) cell-associated markers (Valpha24 and CD56) and perforin in relation to CD44-highly positive (CD44(high)) cells was studied in hyperplastic thymuses from patients with myasthenia gravis (MG) whose symptoms dramatically improved after thymectomy and compared with non-MG control thymuses. In the control thymuses, Valpha24-positive (Valpha24(+)) and CD56-positive (CD56(+)) cells were sparsely distributed in the medullary area only. In contrast, in hyperplastic MG thymus, Valpha24(+) and CD56(+) cells were more frequent in connective tissue, appeared to have penetrated the thymic parenchyma, and most coexpressed CD44(high). Perforin-positive cells were not present in the control thymus, but were in the connective tissue and perilobular cortical areas in the hyperplastic MG thymus. Most of these perforin-positive cells were CD44(high) and were located near blood vessels. They appeared to have migrated directly from the vascular system and penetrated the thymic parenchyma. Some perforin-positive cells coexpressed Valpha24, CD56, or both. These findings suggest that in this particular type of MG thymus, NKT-like cells may have increased via a CD44- and perforin-mediated mechanism, leading to an imbalance in the immune system that favored an antibody-mediated autoimmunity against the acetylcholine receptor.

Symptomatic characteristics of parkinsonism and the width of substantia nigra pars compacta on MRI according to ischemic changes in the putamen and cerebral white matter: implications for the diagnosis of vascular parkinsonism

To investigate the significance of vascular lesions as a cause of secondary parkinsonism, we analyzed the symptomatic characteristics, the width of the substantia nigra pars compacta (SNpc) on MRI and the responsiveness to L-dopa in 227 parkinsonian cases, excluding those with drug-induced parkinsonism and neurodegenerative diseases other than idiopathic Parkinson's disease (IPD). They were classified into those without a significant infarct in the basal ganglia (n = 144), those with status lacunaris in the putamen (SLP; n = 66) and those with confluent white matter hyperintensity signals (CWMH; n = 17). The 4- to 6-Hz tremor and cogwheel rigidity were significantly more frequent in cases without significant infarct (69%) than those with SLP (50%) and those with CWMH (12%; p < 0.05). Among cases with 4- to 6-Hz tremor and cogwheel rigidity, the frequency of patients with a reduced SNpc width and L-dopa responders did not significantly differ between those with SLP (73 and 83%, respectively) and those without significant infarct (83 and 86%, respectively), suggesting that the diagnosis for most of these cases would be probable IPD. In contrast, among cases without 4- to 6-Hz tremor and cogwheel rigidity, those with a reduced SNpc width or L-dopa responders were significantly less frequent among cases with SLP (25 and 38%, respectively) than among those without significant infarct (75 and 71%, respectively; p < 0.05). Patients with neither 4- to 6-Hz tremor and cogwheel rigidity nor reduction in the SNpc width, for whom the probable diagnosis was vascular parkinsonism (VP), were significantly more frequent in cases with SLP (26%) and with CWMH (40%) than those without significant infarct (8%), accounting for 10.6% of the total parkinsonian cases. These findings suggest that parkinsonian cases with SLP or CWMH consist of not only cases with vascular-lesion-related VP but also IPD in which vascular lesions are not directly related to parkinsonism. Absence of 4- to 6-Hz tremor, cogwheel rigidity and the reduction in the SNpc width could be indicators for differentiating VP from IPD.

[A case of flutter-like oscillation with anti-GD1a antibody after acute infection]

We report a 31-year-old woman presenting flutter-like oscillation after acute infection. Ten days after low fever and diarrhea, she presented transient, horizontal and pendular ocular oscillation. This abnormal eye movement was diagnosed as flutter-like oscillation (FLO). Other neurological findings were normal. Cerebrospinal fluid was normal. Brain MRI revealed no particular abnormalities. Serum titers for anti-GD1a antibody were elevated. After treatment with steroid (1,000 mg/day methylprednisolone DIV), the FLO disappeared.

Disorganised unilateral cerebellar folia: a mild form of cerebellar cortical dysplasia?

We describe MRI findings in two patients with disorganised foliation of one cerebellar hemisphere, with folia running vertically rather than horizontally. The thickness of individual folia and corticomedullary interdigitations were normal. These patients have no cerebellar neurological deficit. This rare abnormality is probably a maldevelopment of the hemispheric part of the posterior lobe of the developing cerebellum, and no clinical significance can be elicited.

[A case with trigeminal herpes zoster manifesting a long lesion of the spinal trigeminal nucleus and tract on MR T2-weighted image]

We reported a 53-year-old man with the right trigeminal herpes zoster with preceding neuralgia (preherpetic neuralgia) in the right upper cervical nerve area. He developed dysesthesia and scapular pain in the right second cervical nerve area. 5 days later, herpes zoster emerged in the area of the right maxillary division of trigeminal nerve. Furthermore, he developed paralysis on the right facial muscle on the 12th day after the onset of scapular pain. Neurological examination revealed decrease in superficial sensation accompanied by pain and dysesthesia in the areas innervated by the right maxillary division of trigeminal nerve and the right second cervical nerve, and the right peripheral facial nerve palsy. Any rash was not observed in the right second cervical nerve area throughout the course. The cerebrospinal fluid showed a mild mononuclear pleocytosis. The antibody titer for varicella zoster virus (VZV) was elevated in both cerebrospinal fluid and blood serum. T2-weighted magnetic resonance (MR) image revealed a continuously long high-signal lesion corresponding to the right spinal trigeminal nucleus and tract, extending from the lower pons to the second cervical segment of the spinal cord. This lesion could have resulted from a centripetal migration of VZV from the Gasser ganglion to the spinal trigeminal nucleus and tract, which was probably related to the preherpetic neuralgia in the upper cervical nerve area without rash.

Activated coagulation/fibrinolysis system and platelet function in acute thrombotic stroke patients with increased C-reactive protein levels

The relationship between systemic infection or inflammation and an increased risk of thrombotic diseases has recently raised renewed interest. In order to determine the mechanisms underlying this relationship, we determined plasma levels of coagulation/fibrinolysis markers and platelet function in patients with acute thrombotic stroke (<24 h after onset) prior to treatment, and compared the results between cases with elevated and normal C-reactive protein (CRP) levels and controls. Plasma levels of thrombin-antithrombin complex (TAT), plasmin-antiplasmin complex, and D-dimer were significantly higher in patients with elevated CRP levels than in those with normal CRP levels and controls (P<0.005). Platelet aggregation induced by 1 and 10 microM ADP was significantly higher in patients with elevated CRP levels than those with normal CRP levels (P<0.05). These findings suggest that activation of the coagulation/fibrinolysis system and platelet function may be in part related to stroke onset in patients with increased CRP levels.

Hypoxia-induced expression of C1q, a subcomponent of the complement system, in cultured rat PC12 cells

This study investigated the effect of exposure to hypoxia on the expression of C1q mRNA and protein in cultured PC12 cells. PC12 cells expressed neither C1q mRNA nor protein before hypoxia. However, the cells expressed C1q mRNA immediately after hypoxia, and then A, B, and C chains of C1q and higher molecular weight C1q proteins during reoxygenation. Under the same experimental conditions, cell membrane disintegration began during hypoxia, whereas DNA fragmentation initiated during reoxygenation later than C1q protein expression. These results suggest that in response to hypoxia, PC12 cells per se express C1q mRNA and protein in the early phase before initiation of DNA fragmentation in the absence of any influence of other cellular components. These findings may be relevant for the pathogenesis and treatment of stroke.

Increased expression of alpha7 nAChR after transient hypoxia in PC12 cells

We examined the effects of transient (6 h) hypoxia on nicotinic acetylcholine receptor (nAChR) subunit alpha7 expression in cultured PC12 cells, using RT-PCR and cytochemistry for alpha-bungarotoxin (alphaBTX) binding sites. The relative amount of alpha7 subunit mRNA compared with that before hypoxia decreased to 84% immediately after hypoxia, but then began to increase at 6 h after hypoxia, reaching 171% at 12 h. After this point, it decreased again to 81% at 48 h. Until 6 h after hypoxia, cells appeared to shorten their neurites and form aggregates, without any accompanying remarkable change in alphaBTX binding sites compared with before hypoxia. However, at 12 h and 24 h after hypoxia, alphaBTX binding sites remarkably increased, whereafter cells resumed outgrowth of their neurites at 24-48 h. These findings suggested that nAChR subunit alpha7 was upregulated in both mRNA and protein levels in response to transient hypoxia/reoxygenation in PC12 cells.

Protective effect of nicotine through nicotinic acetylcholine receptor alpha 7 on hypoxia-induced membrane disintegration and DNA fragmentation of cultured PC12 cells

To investigate the effect of nicotine on hypoxic neuronal damage, cultured PC12 cells were exposed to hypoxia for 9 h and then reoxygenated for 72 h. The cells were stained by propidium iodide (PI), a marker of cell membrane disintegration and the TUNEL method, which indicates DNA fragmentation. In control cultures, the ratio of PI-positive cells to total cells progressively increased during and after exposure to hypoxia, constituting 39% of total cells at 72 h posthypoxia. This increase in PI-positive cells was completely inhibited by nicotine until 12 h posthypoxia, and was partially and dose-dependently inhibited thereafter. The ratio of TUNEL-positive cells to total cells started to increase at 24 h posthypoxia and reached 36% at 72 h in control cultures. This ratio was also dose-dependently inhibited by nicotine. These inhibitory effects of nicotine on the increase in PI-positive and TUNEL-positive cells were abolished by the addition to the medium of alpha-bungarotoxin, an antagonistic ligand for nicotinic acetylcholine receptor (AChR) alpha7. These findings suggest that nicotine inhibits, through AChR alpha7, hypoxia-induced cell membrane disintegration and DNA fragmentation of cultured PC12 cells exposed to hypoxia.

Marked increase in CD44-highly positive cells in hyperplastic thymuses from patients with Myasthenia gravis

To investigate the role of the thymus in the pathogenesis of myasthenia gravis (MG), immunohistochemical expression of CD44, CD45R0, B7-1, and IL-2 was studied in: (1) hyperplastic thymuses of patients with MG whose symptoms markedly improved after thymectomy, (2) remnant thymuses of patients with MG whose symptoms did not respond to thymectomy, and (3) non-MG control thymus. Lymphocytes strongly expressing CD44, a marker for homing lymphocytes and activated memory lymphocytes in adults, were much more frequently observed in hyperplastic MG thymuses than in remnant thymuses and non-MG control thymuses. These CD44-highly positive cells in hyperplastic MG thymuses were for the most part located in the subcapsular and cortical areas but also occasionally in medullary areas. Some of these CD44-highly positive cells coexpress CD45R0. CD44-highly positive cells were located in the vicinity of blood vessels and thus appeared to have migrated directly from extralobular blood vessels. B7-1-positive cells and interleukin (IL)-2-positive cells were also more abundant in the MG patients than in controls and were localized in the proximity of CD44-highly positive cells. These findings suggest that mature T and B cells recirculate into hyperplastic MG thymus via CD44-associated mechanisms and are activated there.

PCR amplification in bisulfite methylcytosine mapping in the GC-rich promoter region of amyloid precursor protein gene in autopsy human brain

Alterations in DNA 5-methyldeoxycytidine pattern influence gene expression for certain mammalian genes in development, differentiation, carcinogenesis, and aging. Detection of DNA methylation at the promoter region, which generally represses transcription activity, is one important element in studying changes in molecular expression with aging and age-associated disorders. Bisulfite genomic sequencing is a useful method for mapping methylated cytosines. However, PCR amplification for bisulfite-treated DNA does not yield a sufficient amount of products that have a sufficient level of specificity, especially in the GC-rich sequences usually seen at the promoter regions of house keeping genes. We present a method for increasing the sensitivity and specificity of PCR amplification in bisulfite methylcytosine mapping in an extremely GC-rich promoter region of amyloid precursor protein (APP) gene from the cerebral cortex of human autopsy brain. The PCR used consists of two cycles using the lower primer alone to amplify the sense sequence, and then eight cycles at a theoretical annealing temperature (60 degrees C) and 30 cycles at a lower annealing temperature (50 degrees C) using both the upper and lower primers. The present method likely can also be applied to other GC-rich genomic sequences.

The methylation status of cytosines in a tau gene promoter region alters with age to downregulate transcriptional activity in human cerebral cortex

Changes with age in the methylation status of cytosines in a promoter region of the tau gene were investigated in autopsy human cerebral cortex, using the bisulfite method, polymerase chain reaction (PCR) and direct sequencing of PCR products. While the total number of methylcytosines decreased with age, the changes in methylation status differed among transcription factor binding sites. Cytosines in the AP2-binding sites were never methylated in any of the cases studied at any age. Methylcytosines in the binding sites for Sp1, a transcriptional activator, significantly increased with age, whereas those in the binding sites for GCF, a repressor of GC-rich promoters, significantly decreased with age. These findings suggest that the methylation status of cytosines in the promoter region of the tau gene alters with age to decrease its transcriptional activity in the human cerebral cortex.

Changes with aging and ischemia in nicotinic acetylcholine receptor subunit alpha7 mRNA expression in postmortem human frontal cortex and putamen

Age-related changes in nicotinic acetylcholine receptor (nAChR) subunit alpha7 messenger RNA (mRNA) expression in postmortem human frontal cortex and putamen of controls and status lacunaris patients were investigated using nonradioactive reverse transcription(RT)-PCR. In the frontal cortex of control brains, alpha7 subunit mRNA significantly decreased with age (P < 0.05). In the putamen, alpha7 subunit mRNA expression was significantly lower than that in the frontal cortex (P < 0.0001), and showed no significant correlation with age. However, in cases with status lacunaris in the putamen, alpha7 subunit mRNA expression was significantly higher compared with controls (P < 0.001). The reduction in alpha7 nAChR in the frontal cortex with age may decrease functional cholinergic synapses and cortical activity, and play a role in the cognitive impairments associated with normal aging. The functional significance of the upregulation of alpha7 nAChR mRNA in ischemic conditions remains to be determined.

The effect of trihexyphenidyl, an anticholinergic agent, on regional cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

Cerebral blood flow and oxygen metabolism were studied in six previously untreated patients with Parkinson's disease (PD) before and after anticholinergic treatment using positron emission tomography (PET) and compared with six controls. The PET study and an assessment of the disability and cognitive impairment were performed before and after administration of 6 mg trihexyphenidyl for 5 to 11 weeks. All PD patients showed improvements in motor symptoms after the trihexyphenidyl treatment. Cognitive function did not significantly differ between before and after trihexyphenidyl treatment. However, after trihexyphenidyl treatment, rCBF and rCMRO2 decreased by 15% in the striatum and by 10% in all cortical areas contralateral to predominantly symptomatic limbs, and by 10% in the ipsilateral striatum and all cortical areas, significantly below the values of controls in most cerebral cortices and striatum. These findings suggest that trihexyphenidyl inhibits the cortical cholinergic system and significantly decreases rCBF and rCMRO2 in the cerebral cortices without cognitive impairment in untreated patients with PD.

Local variation in expression of pro- and antithrombotic factors in vascular endothelium of human autopsy brain

The expression of tissue factor (TF), tissue factor pathway inhibitor (TFPI), von Willebrand factor (vWF), endothelial nitric oxide (NO) synthase (eNOS), tissue plasminogen activator (tPA), its inhibitor (PAI-1), and myosin, an indicator of local shear stress, was examined in the endothelium of cerebral vessels according to vessel size and location in human autopsy brains, using immunohistochemistry. Expression of TF, vWF, eNOS, tPA/PAI-1, and myosin was much greater in intracerebral perforating arteries and the microvasculature than the pial and carotid arteries. Expression of all antigens studied was normally faint or negative in the pial and carotid arteries. However, TF, vWF, myosin, tPA, and PAI-1 were strongly expressed in the endothelium of the inner wall of the carotid bifurcation where flowing blood collides, but not in the outer wall. In the endothelium of arteries with fibrillary hyperplasia, vWF, myosin, eNOS, tPA, and PAI-1 were strongly expressed. Within the brain, microvascular expression of TFPI was very faint or negative, whereas that of vWF was intense throughout all brain regions. However, expression of TF and myosin was more intense in the basal gray matter and white matter than in the cortex. eNOS was expressed more strongly in the basal gray matter and cortex than the white matter, whereas tPA and PAI-1 expression was more intense in the white matter than the gray matter. In addition to intrinsic properties of individual vessels, these local variations in expression of pro- and antithrombotic factors in cerebral vessels may in part be due to differences in hemorheological and humoral environments to which they are exposed, and may result in local difference in vulnerability to ischemia. The present findings may in part account for the propensity of thrombus generation in the carotid inner wall, an usual source of artery-to-artery microemboli, frequent development of lacunar (small) infarcts in deep brain regions, and diffuse white matter lesions as seen in Binswanger's leukoencephalopathy.

Reduction with age in methylcytosine in the promoter region -224 approximately -101 of the amyloid precursor protein gene in autopsy human cortex

Methylation status of cytosines and its changes with age in the promoter region (-226 approximately -101) of the amyloid precursor protein (APP) was analyzed using bisulfite genomic sequencing in the cerebral cortex of human autopsy brain. Cytosines at 13 locations were methylated in at least one of the cases studied. Methylcytosines at these locations was more frequent in cases </=70 years old (26%) than in cases >70 years old (8%) (p<0.05). Cytosines at -207, -204, -200, and -182 are frequently methylated, and the frequency of methylcytosine in these locations was significantly higher in cases </=70 years old (55%) than cases >70 years old (5%) (p<0.01). These cytosines constituted one of the 9-bp-long GC-rich elements (GGGCGC G/A GG) or an 11-bp inverted repeat (GGCCGT CGGCC). The present findings indicate that some cytosines, particularly those at -207 approximately -182, in the promoter region of the APP gene are frequently methylated and suggest that their demethylation with age may have some significance in the development of Abeta deposition in the aged brain. The relative importance of these elements in the total promoter activity of the APP gene remains to be definitively established.

Alterations of 3-nitrotyrosine concentration in the cerebrospinal fluid during aging and in patients with Alzheimer's disease

To investigate the significance of nitric oxide (NO)-mediated neuron death in aging and Alzheimer's disease (AD), the 3-nitrotyrosine concentration in the cerebrospinal fluid (CSF) was investigated in neurologically normal controls and patients with AD. The 3-nitrotyrosine concentration and the 3-nitrotyrosine/tyrosine ratio significantly increased with advancing age, whereas the tyrosine concentration was unaltered. In patients with AD, the 3-nitrotyrosine concentration and the 3-nitrotyrosine/tyrosine ratio increased significantly (>six-fold) compared with controls of similar age, and increased significantly with decreasing cognitive functions, whereas the tyrosine concentration did not change. These findings suggest that an activation of tyrosine nitration, increase in nitrated tyrosine-containing proteins, and/or its degradation may be involved in brain aging and play an important role in the pathogenesis of AD.

Remarkable increase in cerebrospinal fluid 3-nitrotyrosine in patients with sporadic amyotrophic lateral sclerosis

To investigate the significance of peroxynitrite-mediated oxidative damage in the pathogenesis of sporadic amyotrophic lateral sclerosis (SALS), the concentrations of 3-nitrotyrosine and tyrosine in the cerebrospinal fluid (CSF) of patients with SALS were determined. The concentration of 3-nitrotyrosine and the 3-nitrotyrosine/ tyrosine ratio in patients with SALS were approximately seven times those of controls. Thus, the present findings in living patients provide in vivo evidence for a possible role of peroxynitrite, a mediator of oxidative stress, and increased nitration of tyrosine residues in the pathogenesis of SALS.

Quantitation of nicotinic acetylcholine receptor subunits alpha 4 and beta 2 messenger RNA in postmortem human brain using a non-radioactive RT-PCR and CCD imaging system

We present a simple and rapid procedure for quantifying mRNA in the brain after RT-PCR, in which the intensity of the ethidium bromide luminescence of PCR products is measured directly from electrophoretic gels by a highly sensitive CCD camera combined with an image analyzing computer system (Gel Doc 1000 system). The CCD camera allows the mRNA in the ethidium bromide-stained PCR-amplified bands to be quantified in a broad exponential range of PCR cycles. The proposed protocol enables standard curves to be constructed to examine the relationship between the number of reaction cycles and amplified log intensity and between the amount of sample RNA for RT-PCR and amplified intensity. The method was applied to nicotinic acetylcholine receptor (nAChR) subunits alpha 4 and beta 2 mRNA in postmortem human putamen in the present study, but is also applicable to mRNAs of other receptors and neurotransmitter precursor peptides.

[The effect of lymphocytapheresis on multiple sclerosis]

We studied the effect of lymphocytapheresis (LCP) on the expanded disability status scale (EDSS) clinical score, lymphocyte subsets and Interleukin-2 (IL-2) production by peripheral blood mononuclear cell (PBM) in 5 patients with multiple sclerosis (MS). The EDSS clinical score significantly decreased after LCPs (p < 0.05). PBM IL-2 production and CD 4/8 ratio significantly decreased (p < 0.05, p < 0.05), and the number of neutrocytes and CD 11 b+CD 8+ (%) significantly increased immediately after LCP (p < 0.05, p < 0.05). Down-regulation of PBM IL-2 production and CD 4/8 ratio and up-regulation of CD 11 b+CD 8+ may account for therapeutic effect of LCP on MS. However, similar changes were observed in patients with CIDP and MG during immunoadsorbent therapy (IAT). It is possible that down-regulation of PBM IL-2 production and CD 4/8 ratio and up regulation of CD 11 b+CD 8+ and the number of neutrocytes may commonly result from apheresis therapy using extra-corporeal circulation.

An endogenous MPTP-like dopaminergic neurotoxin, N-methyl(R)salsolinol, in the cerebrospinal fluid decreases with progression of Parkinson's disease

There have been an increasing number of evidences indicating that dopamine-derived N-methyl(R)salsolinol is an endogenous MPTP-like neurotoxin to cause Parkinson's disease. In the cerebrospinal fluid from newly diagnosed untreated patients with Parkinson's disease, the level of this toxin was found to increase significantly, compared to control and a disease control, multiple system atrophy. The effects of the disease duration and the medication on the level of N-methyl(R)salsolinol were studied from the same patients. After about a 2-year period, the level was significantly reduced. The depletion of dopamine neurons by the disease progression may account for the reduction of the neurotoxin level, whereas L-DOPA therapy did not seem to affect the level of this toxin, even though the enhanced dopamine turnover. The results suggest that N-methyl(R)salsolinol level in the cerebrospinal fluid may indicate remaining dopamine neurons in the parkinsonian brain.

Decrease with age in methylcytosines in the promoter region of receptor for advanced glycated end products (RAGE) gene in autopsy human cortex

Changes with age in the methylation status of cytosines in the promoter region of the receptor for advanced glycated end products (RAGE) in autopsy human cortex were investigated, using the bisulfite method, polymerase chain reaction (PCR), and direct sequencing of PCR products. The total number of methylcytosines significantly decreased with age. While the number of methylated cytosines at CpG dinucleotides was stable throughout adult life, that at sites other than CpG dinucleotides significantly decreased with age in cases >/=70 years old. Of 13 transcription factor binding sites, cytosines in CpG doublets in NF-IL6 and SP-1 binding sites were methylated in all cases, suggesting that these sites are repressed throughout adulthood. In contrast, the number of methylcytosines in AP-2 or SP-1 binding sites located at CpC, CpA, or CTG was significantly lower or at least tended to be lower in cases >/=70 years than <70 years old. These reductions in the number of methylcytosines at transcription factor binding sites may increase expression of RAGE, which may in turn play a role in aging of the brain.

Increase in oxidized NO products and reduction in oxidized glutathione in cerebrospinal fluid from patients with sporadic form of amyotrophic lateral sclerosis

To determine the role of free radical mechanisms in the pathogenesis of amyotrophic lateral sclerosis (ALS), cerebrospinal fluid concentrations of oxidized nitric oxide (NO) products (nitrite and nitrate) and reduced and oxidized forms of glutathione (GSH and GSSG, respectively) were compared between patients with the sporadic form of ALS (SALS) and controls. In the SALS patients, the nitrate levels were significantly higher (by 73%) in contrast to remarkably lower GSSG/GSH ratio, approximately 3-fold, compared to controls. These results suggest that NO production or oxidation is activated in SALS patients, leading to a decrease in superoxide radicals to oxidize GSH. The subsequent generation of a highly reactive anion, peroxynitrite, may play a causal role in the pathogenesis of SALS.

The cerebrospinal fluid oxidized NO metabolites, nitrite and nitrate, in Alzheimer's disease and vascular dementia of Binswanger type and multiple small infarct type

The concentration of the nitric oxide (NO) metabolites nitrite (NO2-) and nitrate (NO3-) in the cerebrospinal fluid from patients with Alzheimer's disease (AD), vascular dementia of the Binswanger type (VDBT) or multiple small infarct type (MSID), and controls were determined using high performance liquid chromatography. The nitrite concentration was significantly higher in VDBT/MSID patients than in controls (p < 0.005). The nitrate concentration and the combined nitrite and nitrate concentration was significantly higher in both AD (p < 0.05) and VDBT/MSID (p < 0.001) patients than in controls, with these concentrations being significantly greater in VDBT/MSID than AD patients (p < 0.005). The combined nitrite and nitrate concentration significantly decreased as the severity of dementia progressed in AD (rs=0.70, p < 0.01), but remained elevated in all stages of VDBT/MSID. These results suggest that NO production or oxidation in the brain increases in the early stage of AD and then decreases as neuronal cell loss progresses, but increases throughout the course of disease in VDBT/MSID, which may in part contribute to neuronal degeneration in both conditions.

Familial amyloid polyneuropathy related to transthyretin mutation Val30 to Leu in a Japanese family

A rare variant transthyretin that has a leucine-for-valine substitution at position 30 was reported in a sporadic case of type 1 familial amyloid polyneuropathy (FAP). We found the same substitution in members of a Japanese family with FAP. Three individuals in this family had a guanine-to-cytosine mutation at the first base of codon 30 in exon 2. This family shows a direct link between a valine-to-leucine substitution at position 30 and type 1 FAP.

Cerebral blood flow and oxygen metabolism before and after a stroke-like episode in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

Cerebral blood flow and oxygen metabolism were examined in two patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) using positron emission tomography (PET). Regional cerebral blood flow (rCBF), regional cerebral oxygen metabolic rate (rCMRO2) and regional oxygen extraction fraction (rOEF) were determined with the steady-state technique using oxygen-15-labeled tracers (15O2, C15O2 and C15O). Case 1, a 45-year-old woman, presented with abrupt onset of fluent aphasia. T2-weighted magnetic resonance imaging (MRI) showed a high signal intensity lesion in the left temporoparietal region. The first PET study on day 16 showed increased rCBF and decreased rCMRO2 in the temporal region. In the second PET study, on day 35, rCBF in the temporal region had decreased. Case 2 was a 19-year-old male; the second son of Case 1. He complained of transient blurring of vision, and then generalized tonic-clonic convulsion occurred. A PET study six days before this stroke-like episode demonstrated increased rCBF in both frontal lobes and putamen, where MRI showed lesions after the episode. Focal hyperemia of the lesion antedated and lasted for at least sixteen days after the stroke-like episode in these MELAS patients. These stroke-like episodes appear to be the result of metabolic dysfunction in neural tissue, although the role of an ischemic vascular event cannot be ruled out.

Tissue-specific involvement of multiple mitochondrial DNA deletions in familial mitochondrial myopathy

It is still uncertain how deleted mitochondrial DNA (mtDNA) is distributed to each tissue during development, although deletions of mtDNA have been extensively observed in various pathologic conditions. This paper presents two Japanese siblings with progressive external ophthalmoplegia exhibiting multiple mtDNA deletions. In one patient, similar multiple mtDNA deletions were found in skeletal muscle specimens as well as in the spinal cord but not in the myocardium, liver or leukocytes. A similar deletion pattern was found in the skeletal muscle but not in the leukocytes of the other patient. The results suggest the complex mechanism to generate, expand and eliminate the deleted mtDNA in humans.

Alterations with aging and ischemia in nicotinic acetylcholine receptor subunits alpha4 and beta2 messenger RNA expression in postmortem human putamen. Implications for susceptibility to parkinsonism

Nicotine activates the dopaminergic system and acts to alleviate hypokinetic disorders (parkinsonism). The frequency of parkinsonism increases with age and is sometimes associated with multiple small infarcts (status lacunaris) in the putamen. To investigate changes with aging in control cases free from neurological disease and changes in cases with multiple small infarcts (status lacunaris) in the putamen, the present study determined nicotinic acetylcholine receptor (nAChR) subunit alpha4 and beta2 messenger RNA (mRNA) expression in the postmortem human putamen using the reverse transcription-polymerase chain reaction (RT-PCR). In controls, alpha4 subunit mRNA expression was unaltered, but beta2 subunit mRNA expression decreased significantly with age. In cases with status lacunaris, both beta2 and alpha4 subunit mRNA expressions were significantly lower than in the control cases. The reduction in beta2 mRNA expression alone, or in both alpha4 and beta2 mRNA expressions, suggests a reduction in functional nAChRs in the putamen, which may in part explain the susceptibility to hypokinetic disorders of the elderly and subjects with ischemic damage in the striatum.

Age-related changes in nicotinic acetylcholine receptor subunits alpha4 and beta2 messenger RNA expression in postmortem human frontal cortex and hippocampus

Age-related changes in nicotinic acetylcholine receptor (nAChR) subunit alpha4 and beta2 messenger RNA (mRNA) expression in the postmortem human frontal cortex and hippocampus was investigated using the reverse transcription-polymerase chain reaction (RT-PCR). In the frontal cortex, both alpha4 and beta2 subunit mRNA expression decreased with age. In the hippocampus, alpha4 subunit mRNA expression was unaltered, while beta2 subunit mRNA expression significantly decreased with age. These findings suggest that nAChR transcription decreases during aging with differing vulnerability between subunits and brain regions, which could in part contribute to the reduction in cognitive functions seen in the elderly.

Cerebral blood flow and oxygen metabolism in senile dementia of Alzheimer's type and vascular dementia with deep white matter changes

Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO2), oxygen extraction fraction (rOEF), and cerebral blood volume (rCBV) were investigated using positron emission tomography (PET) in 16 patients with senile dementia of Alzheimer's type (SDAT), and compared with those of 6 nondemented and 3 demented patients with deep white matter high signal (DWMH) on T2-weighted MRI and 6 controls. rCBF, rCMRO2 and rCBV were determined using C15O2, 15O2 and C15O, respectively. rCBF and CMRO2 were significantly decreased in the frontal, parietal and temporal cortex (P < 0.05) in patients with SDAT, and showed a significant correlation with the severity of dementia (P < 0.05). In patients with DWMH rCBF was significantly decreased in the parietal cortex and in the frontal white matter in nondemented patients, and in the cerebral cortex and white matter of most regions studied in demented patients (P < 0.05), whereas rCMRO2 was significantly reduced in only the frontal and temporal cortex of demented patients (P < 0.05). rOEF was significantly increased in the parietal cortex of patients with SDAT and in the white matter of patients with SDAT or DWMH (P < 0.05), and the increase in the frontal white matter significantly paralleled the progression of dementia in patients with SDAT (P < 0.05). rCBV was significantly decreased in the parietal and temporal cortex of patients with SDAT (P < 0.05), but not in any areas of those with DWMH. These results suggest that rOEF is increased in both SDAT and patients with DWMH. The increase in rOEF in patients with SDAT may be accounted for by reduction in rCBV resulting from decreased activity in the vasodilatory cholinergic system, impairment of glucose metabolism and white matter changes; the rOEF increase in patients with DWMH suggests relative preservation of oxidative metabolism compared to disturbed perfusion.

Age-related changes in D1 and D2 receptor mRNA expression in postmortem human putamen with and without multiple small infarcts

Expression of messenger RNAs (mRNAs) encoding the D1 and D2 dopamine receptors as a function of age was determined in the human putamen using the reverse transcription-polymerase chain reaction (RT-PCR). In cases without multiple small infarcts (status lacunaris) in the putamen, D1 mRNA expression was unaltered, while D2 mRNA expression significantly decreased with age. Both D1 and D2 mRNA expression was lower in cases with status lacunaris. The reduction in D1 receptors primarily located on striatonigral neurons or D2 receptors primarily located on striatopallidal neurons may inhibit thalamocortical neurons. The decreased transcription of D1 and D2 receptor genes may in part account for increased susceptibility to hypokinetic disorders in the elderly.

[A case of chronic, motor, axonal polyneuropathy successfully treated by immunoadsorption]

We reported a 61-year-old male with chronic, motor, axonal polyneuropathy. Neurological examination revealed severe muscle weakness in the proximal parts of the four limbs. Sensory examination was normal. The cerebrospinal fluid protein was elevated to 74 mg/dl, and the cell count was normal. The serum antibodies to GM1, GD1a, GD1b, and GQ1b were all negative. Electrophysiological studies showed reduced compound muscle action potentials (CMAPs) suggesting axonal neuropathy, and the nerve conduction velocity was only mildly reduced. After treatment with plasmapheresis (PP) by the immunoadsorption method, his symptoms significantly improved in three weeks, and the cerebrospinal fluid protein, and CMAPs also improved. Only a few studies have been reported regarding patients with chronic, motor dominant, axonal polyneuropathy that responded to immunosuppressive therapies or PP. It remains to be determined whether chronic, dominantly motor, axonal polyneuropathy as seen in the present case is a subtype of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or a primary axonal immune-mediated neuropathy that is different from CIDP. At present we are not able to answ what kind of clinical or laboratory markers other than an elevated cerebrospinal fluid protein level may help to predict a positive response to immunosuppressive therapy or PP.

[Effects of CTG repeat expansion on quantitative muscle histopathology in myotonic dystrophy]

The CTG trinucleotide repeat (CTG repeat) length in leukocytes and muscles shows significant correlations with muscle weakness, an increase in type 1 fiber proportion, and reductions in type 2A and 2B fiber proportions in patients with myotonic dystrophy (DM). The correlations are generally greater for CTG repeat length in muscles than in leukocytes. However, relatively small absolute values of correlation coefficients (r2 = 0.13-0.43) suggest that the CTG repeat length is not a role variable that may explain clinical and histopathological changes in DM patients.

Reduced size of right hippocampus in 39- to 80-year-old normal subjects carrying the apolipoprotein E epsilon4 allele

Hippocampal size on magnetic resonance imaging was compared between normal subjects with the apolipoprotein E (apo E) epsilon4 allele (epsilon4/4, epsilon4/3, and epsilon4/2) and those without the epsilon4 allele (epsilon3/3, epsilon3/2, and epsilon2/2) in the age range of 39-80 years. The Mini-Mental State Examination (MMSE) scores did not differ between the two groups. The right hippocampal area and its ratio to hemisphere area and intracranial cavity area were significantly smaller in epsilon4 carriers than non-carriers, whereas hemisphere area did not differ between the two groups. These results suggest that as early as their forties, apo E epsilon4 allele carriers have a markedly smaller right hippocampus with no apparent cognitive impairment, which may have some significance in the high prevalence of the epsilon4 allele in Alzheimer's disease as well as other conditions that cause dementia.

Concentration of catecholamines and indoleamines in the cerebrospinal fluid of patients with vascular parkinsonism compared to Parkinson's disease patients

The concentration of catecholamines and indoleamines in the cerebrospinal fluid of patients with vascular parkinsonism (VP) was compared to that in patients with Parkinson's disease (PD) and controls. Compared to the controls, the concentration of tyrosine was significantly higher, and the concentration of L-dopa and 3-O-methyldopa (3-OMD) was significantly lower in both VP and PD patients. The balance between the 3-OMD/L-dopa and dopamine (DA)/L-dopa ratios was changed in favor of 3-OMD/L-dopa in both VP patients and PD patients suggesting the preservation of a compensatory mechanism. All these changes were less marked in VP patients than in PD patients. A remarkable finding was that in contrast to PD patients the concentration of DA and norepinephrine (NE) was significantly higher in VP patients than in the controls. The decrease in the concentration of 5-hydroxytryptamine (5-HT) was significantly greater in VP patients than in PD patients. In PD patients, the concentration of DA, NE, and 5-HT showed significant correlation with the severity of motor symptoms. In VP patients, the concentration of 5-HT alone showed significant correlation with the severity of motor symptoms and cognitive dysfunction. These findings suggest that VP patients may have similar disturbances in the DA synthesis pathway as PD patients, but differ from PD patients in that the concentrations of DA and NE are elevated and the decrease in the 5-HT concentration is greater in VP patients.

Reduction in the ratio of beta-preprotachykinin to preproenkephalin messenger RNA expression in postmortem human putamen during aging and in patients with status lacunaris. Implications for the susceptibility to parkinsonism

Gamma-aminobutyric acid (GABA)/substance P (SP) neurons and GABA/enkephalin (Enk) neurons in the striatum exert opposing influence on the regulation of movement. The loss of GABA/SP neurons results in hypokinetic disorders (parkinsonism), whereas the loss of GABA/Enk neurons results in hyperkinetic disorders (e.g. chorea). The present study determined age-related changes in the beta-preprotachykinin (the precursor of SP) and preproenkaphalin (the precursor of Enk) messenger RNA (mRNA) ratio in the postmortem human putamen using the reverse transcription-polymerase chain reaction (RT-PCR). The ratio of beta-preprotachykinin to preproenkephalin mRNA expression decreased with age. The reduction in the beta-preprotachykinin/preproenkephalin mRNA ratio was more marked in cases with multiple small infarcts (status lacunaris) in the putamen. These findings may in part explain the susceptibility of the elderly, particularly of those with ischemic changes in the striatum to hypokinetic disorders.

Effects of tolcapone, a catechol-O-methyltransferase inhibitor, on motor symptoms and pharmacokinetics of levodopa in patients with Parkinson's disease

The effects of tolcapone, a catechol-O-methyltransferase inhibitor, on the bioavailability and efficacy of levodopa were evaluated in 12 patients with Parkinson's disease (PD), 8 of whom showed signs of daily motor fluctuations (wearing-off phenomenon). Motor disabilities were assessed in 12 patients at 7 time points before and after the chronic administration of tolcapone using the Unified Parkinson's Disease Rating Scale (UPDRS). The UPDRS score was improved at all points of determination. Eight patients with wearing-off phenomenon on levodopa showed symptomatic improvement on the combination. The area under the curve (AUC) for levodopa increased by 34% (p = 0.0059) after the administration of tolcapone. The elimination half-life (T1/2) of levodopa was significantly prolonged by 81% (p = 0.0001) after the treatment. The AUC of 3-O-methyldopa, a metabolite of levodopa, was decreased by 79% (p = 0.0001) and the Cmax (maximum concentration) was also decreased by 80%d after the administration (p = 0.0001) of tolcapone. The combination of tolcapone and levodopa was well tolerated. Our findings suggest that tolcapone improves the pharmacokinetics of levodopa in plasma and motor symptoms of fluctuating PD patients. It is suggested that tolcapone may be useful drug adjunct to levodopa in treating patients with PD with wearing-off phenomena.

[TCR alpha beta + CD4- CD8- T cells among the peripheral blood mononuclear cells of myasthenia gravis patients]

We investigated the occurrence of TCR alpha beta + CD4- CD8- mononuclear cells (DN alpha beta T cells) and TCR gamma delta + CD3+ mononuclear cells (gamma delta T cells) among the peripheral blood mononuclear cells of 22 myasthenia gravis patients (MG) and 22 controls in order to examine whether extrathymic T cell subpopulations might be responsible for the pathogenesis of MG. The differences between the mean percentages of both DN alpha beta T cells and gamma delta T cells in the MG patients (DN alpha beta T cells: 0.53 +/- 0.51%, gamma delta T cells: 3.45 +/- 2.79%) and the controls (DN alpha beta T cells: 0.32 +/- 0.16%, gamma delta T cells: 3.81 +/- 2.36%) were not significantly different. However, higher DN alpha beta T cells ratios (1.48 approximately 1.84%) were noted in three MG patients. Thymectomy and subsequent thorough dissection of the anterior mediastinum 3 years after thymectomy had no effect on the symptoms of one patient, a 25-year-old woman without thymoma. The other two patients, a 45-year-old man and a 41-year-old woman without thymoma, had recurrences despite long-term remissions (14 years and 30 years, respectively) after thymectomy. Examination of DN alpha beta T cells, which are probably generated extrathymically without negative selection, may play an important role in understanding the pathogenesis in these three cases of MG.

A dopaminergic neurotoxin, (R)-N-methylsalsolinol, increases in Parkinsonian cerebrospinal fluid

The concentration of (R)-N-methylsalsolinol, which is a dopamine-derived neurotoxin selective to dopamine neurons and induces parkinsonism in rats, was found to be increased significantly in the cerebrospinal fluid of untreated patients with Parkinson's disease. The enantio-specific occurrence of (R)-N-methylsalsolinol in cerebrospinal fluid suggests its enzymatic synthesis in the human brain. The individual differences in the activities of the enzymes determining the metabolism of (R)-N-methylsalsolinol in the brain might be involved in the pathogenesis of Parkinson's disease.

[A case of progressive hemifacial and hemispheric atrophy with multiple hemi-intracerebral calcifications presenting with occipital lobe epilepsy]

A 30-year-old man with progressive hemifacial atrophy is described. He had right hemifacial atrophy and epileptic seizures first noted at the age of about 15 years. Examination revealed atrophy of the right half of the tongue, skin pigmentation in the right neck, grizzled hair on the right side of the head, and left upper temporal homonymous hemianopsia. CT and MRI revealed multiple intracerebral calcifications, and EEG showed spike discharges predominantly in the right occipital lobe, ipsilateral to the hemifacial atrophy. The epileptic seizures were associated with visual hallucinations that are characteristic of occipital epilepsy. A skin biopsy obtained from the pigmented region in the right neck showed chronic inflammatory changes consisting of severe atrophy of the epidermis, dermis, and fatty tissue, marked proliferation of collagen fibers, and perivascular infiltration by round cells and giant phagocytes. Previous descriptions on the pathogenesis of hemiatrophy of the face and brain were reviewed in relation to the present case.

Development of large platelet aggregates from small aggregates as determined by laser-light scattering: effects of aggregant concentration and antiplatelet medication

Particle-counting methods that employ light scattering (LS) quantify changes in the number of platelet aggregates of different sizes after the application of an aggregating stimulus. Using the LS method, we studied the effects of aggregant concentration, aspirin administration, and ticlopidine administration on aggregate formation and compared the results with those obtained using the conventional optical density (OD) method. Subjects were 47 controls, 31 patients treated with aspirin (330 mg/day), and 37 patients treated with ticlopidine (200 mg/day). Platelet aggregation after stimulation by 0.5, 1.0 or 5.0 muM ADP, or 0.5, 1.0 or 2.0 micrograms/ml collagen was determined using both methods. Using the LS method, small (9-25 micrograms), medium (25-50 micrograms), and large (50-70 micrograms) aggregates were counted. In patients untreated with antiplatelet medication, greater concentrations of ADP or collagen generated larger aggregates. Generation of small and medium-sized aggregates showed a significant positive correlation with OD levels after stimulation with 0.5 or 1.0 muM ADP, or 0.5 or 1.0 micrograms/ml collagen. In patients treated with aspirin, the development of small aggregates into large aggregates was inhibited. Thus, the number of small aggregates increased. Inhibition induced by aspirin was more effective against aggregation after stimulation with collagen than with ADP. In patients treated with ticlopidine, small and medium-sized aggregate formation was inhibited after stimulation with low concentrations of ADP or collagen, but was promoted after stimulation with high aggregant concentrations. The capability of the LS method to quantify different sizes of aggregates after stimulation with low concentration agonists may facilitate investigation of the aggregation process, and of how this process is affected by antiplatelet agents.

alpha-Tocopherol quinone level is remarkably low in the cerebrospinal fluid of patients with sporadic amyotrophic lateral sclerosis

In order to investigate the role of free radicals in the pathogenesis of sporadic amyotrophic lateral sclerosis (SALS), the concentrations of alpha-tocopherol (alpha-TOH) and its oxidized form alpha-tocopherol quinone (alpha-TQ) in the cerebrospinal fluid (CSF) of SALS patients were determined. The alpha-TOH level was 31% lower (P < 0.05) and the alpha-TQ level was 75% lower (P < 0.001) in SALS patients than in normal subjects. The results of the present study do not support the hypothesis that activated lipid peroxidation accelerates oxidation of alpha-TOH into alpha-TQ in SALS patients.