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BackgroundThis study aimed to clarify the frequency and clinical features of monogenic cerebral small vessel disease (mgCSVD) among patients with adult-onset severe CSVD in Japan.MethodsThis study included patients with adult-onset severe CSVD with an age of onset ≤55 years (group 1) or >55 years and with a positive family history (group 2). After conducting conventional genetic tests forNOTCH3andHTRA1, whole-exome sequencing was performed on undiagnosed patients. Patients were divided into two groups according to the results of the genetic tests: monogenic and undetermined. The clinical and imaging features were compared between the two groups.ResultsGroup 1 and group 2 included 75 and 31 patients, respectively. In total, 30 patients hadNOTCH3mutations, 11 patients hadHTRA1mutations, 6 patients hadABCC6mutations, 1 patient had aTREX1mutation, 1 patient had aCOL4A1mutation and 1 patient had aCOL4A2mutation. The total frequency of mutations inNOTCH3,HTRA1andABCC6was 94.0% in patients with mgCSVD. In group 1, the frequency of a family history of first relatives, hypertension and multiple lacunar infarctions (LIs) differed significantly between the two groups (monogenic vs undetermined; family history of first relatives, 61.0% vs 25.0%, p=0.0015; hypertension, 34.1% vs 63.9%, p=0.0092; multiple LIs, 87.8% vs 63.9%, p=0.0134).ConclusionsMore than 90% of mgCSVDs were diagnosed by screening forNOTCH3,HTRA1andABCC6. The target sequences for these three genes may efficiently diagnose mgCSVD in Japanese patients.

This study aimed to clarify the frequency and clinical features of monogenic cerebral small vessel disease (mgCSVD) among patients with adult-onset severe CSVD in Japan.This study included patients with adult-onset severe CSVD with an age of onset ≤55 years (group 1) or55 years and with a positive family history (group 2). After conducting conventional genetic tests forGroup 1 and group 2 included 75 and 31 patients, respectively. In total, 30 patients hadMore than 90% of mgCSVDs were diagnosed by screening for

To investigate the pathophysiological mechanisms of immune-mediated peripheral neuropathies, we studied the effects of sera from patients with Guillain-Barré syndrome (GBS) on the Cav2.1 voltage-dependent calcium channel (VDCC) current in Purkinje cells. Using the whole-cell recording technique, Cav2.1 VDCC current was measured in cerebellar Purkinje cells in the presence of serum from GBS patients with acute motor axonal neuropathy (AMAN) or acute inflammatory demyelinating polyneuropathy (AIDP). The AMAN patient sera significantly inhibited the Cav2.1 VDCC current compared with healthy volunteer sera, and this inhibition was fully reversible by washing out the AMAN serum. Similarly, IgG purified from AMAN sera also inhibited the Cav2.1 VDCC current. However, the activation and inactivation kinetics of the Cav2.1 VDCC currents were not affected by serum from an AMAN patient. Moreover, the VDCC current of Purkinje cells was also inhibited by IgG anti-GM1 monoclonal antibody (anti-GM1 mAb). In an immunocytochemical study using double fluorescence staining, Purkinje cells were stained by monoclonal IgG anti-GM1 mAb. In contrast, AIDP patient and healthy volunteer sera did not affect the Cav2.1 VDCC current. These results suggest that in some case of GBS, particularly of AMAN patients with IgG anti-GM1 mAb, muscle weakness may be induced by dysfunction of Cav2.1 VDCC functioning at the motor nerve terminals.

We investigated the expression and localization of Kv1 channels in dorsal spinal roots (DRs) and ventral spinal roots (VRs) in rats. Among Kv1.1-1.6 tested by RT-PCR, mRNAs of Kv1.1, 1.2, and 1.5 were moderately expressed, those of Kv1.3 and Kv1.6 were weakly expressed, and that of Kv1.4 was hardly expressed at all in both DRs and VRs, whereas all six mRNAs were detected in spinal cord. Western blotting revealed that the major immunoreactive proteins were Kv1.1 and Kv1.2 in both DRs and VRs. Quantitative analysis indicated that levels of Kv1.1 and Kv1.2 protein were significantly higher in DRs than VRs. Immunohistochemical examination showed that Kv1.1 and Kv1.2 were colocalized in juxtaparanodal regions of axons in both DRs and VRs. Finally, immunoprecipitation experiments revealed that Kv1.1 and Kv1.2 were coassembled. These findings indicate that Kv1 subtypes in DRs and VRs are somewhat different from those in spinal cord, and that the numbers of Kv1.1 and Kv1.2 channels are higher in DRs than VRs.

We performed an electrophysiological study demonstrating inhibition of spontaneous muscle action potentials within a coculture of rat muscle and spinal cord by exposure to serum, as well as purified IgG, from patients with the acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS). However, exposure to serum from two patients with the acute inflammatory demyelinating polyneuropathy (AIDP) form of GBS had no effect. Using a whole-cell recording technique, we then investigated the effects of serum and purified IgG from patients with GBS on voltage-dependent calcium channel (VDCC) currents in nerve growth factor-differentiated PC12 cells. Serum from patients with GBS (AMAN) inhibited VDCC currents in PC12 cells, which was fully reversible by washing with the bath solution. Similarly, purified IgG from the serum of two patients with GBS (AMAN) also inhibited VDCC currents in PC12 cells. In contrast, sera from patients with AIDP and healthy volunteers did not affect VDCC currents in PC12 cells. These results suggest that muscle weakness in some patients with GBS might be induced by inhibition of Ca2+ channel currents within motor nerve terminals.

Voltage-gated K(+) channels contain six membrane spanning segments and a pore-forming domain. We used site-directed mutation to examine the role of specific amino acids in the extracellular region of the pore in Kv1.2. When expressed in CHO cells, a K(+) current was not observed for mutants S356A, S360A, T383A and T384A. However, coexpression of the Kvbeta2 subunit and the S360A mutant resulted in a robust peak current. Immunocytochemistry for Kv1.2 showed staining throughout the cytoplasm in cells coexpressing the beta2 and S360A, whereas only the perinuclear region was stained in cells expressing the S360A mutant. Western blotting revealed that the major immunoreactive protein in wild-type- and mutant-expressing cells is 60-kDa, but 87-kDa bands were also detected in cells expressing wild-type Kv1.2 and cells coexpressing beta2and S360A. These results suggest that amino acids in the pore region help regulate ion permeability or cellular trafficking by affecting glycosylation of Kv1.2.

We investigated the localization of GalNAc-GD1a biochemically in the human and bovine peripheral nervous system (PNS). The high-performance thin-layer chromatography (HPTLC)-overlay method with rabbit IgG polyclonal antibody against GalNAc-GD1a (anti-GalNAc-GD1a antibody) revealed expression of GalNAc-GD1a in the ventral spinal nerve roots (VRs) but not in the dorsal spinal nerve roots (DRs) of both species. The amount of GalNAc-GD1a in the human and bovine VRs was 2.22 +/- 0.35 microg/g wet tissue and 7.71 +/- 0.49 microg/g wet tissue, respectively. These results suggest that IgG anti-GalNAc-GD1a antibody may be involved in disturbance of peripheral motor nerves and in the pathogenesis of pure motor neuropathy.

We investigated the epitopes and functional role of IgG anti-GalNAc-GD1a antibodies appearing in serum from a patient with Guillain-Barre syndrome (GBS) and IgG anti-GalNAc-GD1a antibody that was produced by immunization of a rabbit with GalNAc-GD1a. Both sera blocked neuromuscular transmission in muscle–spinal cord co-culture cells. The acetylcholine-induced potential did not reduce by adding sera, suggesting that the blockade is presynaptic. The effect was complement-independent and purified IgG from serum of the patient or the rabbit had the same effects. The epitope with both anti-GalNAc-GD1a antibodies was observed in the soma of large neurons in the anterior horns of the adult rat spinal cord and their motor axons of rat ventral roots. Both anti-GalNAc GD1a antibodies reacted strongly with the motor nerve terminals in rats. The anti-GalNAc-GD1a antibodies may block neuromuscular transmission by attacking on presynaptic motor axon, probably affecting the ion channels in the presynaptic motor axon.

Molecular mimicry between microbial and self-components is postulated as the mechanism that accounts for the antigen and tissue specificity of immune responses in postinfectious autoimmune diseases. Little direct evidence exists, and research in this area has focused principally on T cell-mediated, antipeptide responses, rather than on humoral responses to carbohydrate structures. Guillain–Barré syndrome, the most frequent cause of acute neuromuscular paralysis, occurs 1–2 wk after various infections, in particular, Campylobacter jejuni enteritis. Carbohydrate mimicry [Galβ1–3GalNAcβ1–4(NeuAcα2–3)Galβ1-] between the bacterial lipooligosaccharide and human GM1 ganglioside is seen as having relevance to the pathogenesis of Guillain–Barré syndrome, and conclusive evidence is reported here. On sensitization with C. jejuni lipooligosaccharide, rabbits developed anti-GM1 IgG antibody and flaccid limb weakness. Paralyzed rabbits had pathological changes in their peripheral nerves identical with those present in Guillain–Barré syndrome. Immunization of mice with the lipooligosaccharide generated a mAb that reacted with GM1 and bound to human peripheral nerves. The mAb and anti-GM1 IgG from patients with Guillain–Barré syndrome did not induce paralysis but blocked muscle action potentials in a muscle–spinal cord coculture, indicating that anti-GM1 antibody can cause muscle weakness. These findings show that carbohydrate mimicry is an important cause of autoimmune neuropathy.

Injecting muscarinic receptor agonists into a specific area of the brainstem produces an antinociceptive response. The present study investigates whether direct injections of the cholinergic agonist, carbachol, into the rat nucleus reticularis gigantocellularis (NRGC)/nucleus reticularis gigantocellularis alpha (NRGCalpha) of the rostral ventrolateral medulla evokes antinociception, and then examines the interference action of cholinergic antagonists in rats. Microinjections of carbachol (0.75, 1.5, 3 micro g/site) prolonged hot plate (HP) and tail flick (TF) responses to noxious heat stimuli in a dose-dependent manner. The level of carbachol-induced antinociception during the HP and TF tests reached a maximum at 5-15 min after carbachol administration in all groups. Thereafter, the peak level progressively decreased and reached the baseline by the end of the experiment. Antinociception induced by carbachol at 3 micro g/site was attenuated by the prior administration of the muscarinic receptor antagonist, atropine (200, 500 ng/site). On the other hand, the nicotinic autonomic ganglion blocker, mecamylamine (1, 3 micro g/site), did not affect subsequent carbachol-induced antinociception. These results suggest that the antinociceptive effects induced by a microinjection of carbachol depend on muscarinic, but not nicotinic, mechanisms within the rat NRGC/NRGCalpha.

We carried out behavioral, pathological, and biochemical studies in order to determine whether the stereo-structure of 1-methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTIQ) affects the onset of Parkinson’s disease-like symptoms, which are induced by 1,2,3,4-tetrahydroisoquinoline (TIQ) in mice. Pretreatment with (R)-1-MeTIQ or its racemate (RS)-1-MeTIQ prevented the TIQ-induced bradykinesia. Pretreatment with a combination of L-DOPA and carbidopa significantly prevented subsequent TIQ-induced bradykinesia. Furthermore, the pathological study demonstrated that either (R)-1-MeTIQ or its racemate protected against TIQ-induced loss of tyrosine hydroxylase-positive cells of the substantia nigra pars compacta. (R)-1-MeTIQ and its racemate also prevented the TIQ-induced reduction in the levels of dopamine and its metabolites in the striatum. Serotonin and its metabolite were not affected by repeated administration of (RS)-1-MeTIQ or its derivatives. On the other hand, (S)-1-MeTIQ induced moderate but significant bradykinesia, whereas (R)-1-MeTIQ did not induce this behavioral abnormality at all. In addition, (S)-enantiomer prevented the onset of TIQ-induced bradykinesia, though to a lesser extent than did either (R)-enantiomer or its racemate. However, (S)-enantiomer did not prevent the loss of tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta. We concluded that (R)-1-MeTIQ, and not (S)-enantiomer, plays a crucial role in protection against TIQ-induced parkinsonism, a fact which suggests that enantiomeric biochemical events such as 1-MeTIQ biosynthesis may participate in the pathogenesis of Parkinson’s disease.

We administered 1-benzyl-1,2,3,4-tetrahydroisoquinoline (1-BnTIQ; 80 mg/kg, i.p.), an endogenous neurotoxin known to cause bradykinesia, the Parkinson’s disease-like symptom, in order to obtain biochemical and pathological evidence of behavioral abnormalities. Immunohistochemical analysis demonstrated that 1-BnTIQ did not decrease the number of tyrsosine hydroxylase-positive cells in the substantia nigra. Biochemical analysis demonstrated significantly increased striatal dopamine (DA) content, while DA metabolites in the striatum remained at control levels. We concluded that the 1-BnTIQ-induced bradykinesia has a different mechanism of action than that underlying the MPTP-induced depletion of striatal DA neurons.

The binding specificities of amyloid beta-protein (A beta) such as A beta 1-40, A beta 1-42, A beta 40-1, A beta 1-38, A beta 25-35, and amyloid beta precursor protein (beta-APP) analogues for different glycosphingolipids were determined by surface plasmon resonance (SPR) using a liposome capture method. A beta 1-42, A beta 1-40, A beta 40-1, and A beta 1-38, but not A beta 25-35, bound to GM1 ganglioside in the following rank order: A beta 1-42 > A beta 40-1 > A beta 1-40 > A beta 1-38. The beta-APP analogues bound to GM1 ganglioside with a relatively lower affinity. Aged derivatives of A beta were found to have higher affinity to GM1 ganglioside than fresh or soluble derivatives. A beta 1-40 bound to a number of gangliosides with the following order of binding strength: GQ1b alpha > GT1a alpha > GQ1b > GT1b > GD3 > GD1a = GD1b > LM1 > GM1 > GM2 = GM3 > GM4. Neutral glycosphingolipids had a lower affinity for A beta 1-40 than gangliosides with the following order of binding strength: Gb4 > asialo-GM1 (GA1) > Gb3 > asialo-GM2 (GA2) = LacCer. The results seem to indicate that an alpha2,3NeuAc residue on the neutral oligosaccharide core is required for binding. In addition, the alpha2-6NeuAc residue linked to GalNAc contributes significantly to binding affinity for A beta.

We examined the effects of beta-phenylethylamine on striatal acetylcholine release in freely moving rats using in vivo microdialysis. beta-Phenylethylamine at 12.5 mg/kg, i.p. did not affect acetylcholine release in the striatum, whereas 25 and 50 mg/kg, i.p. immediately induced an increase in acetylcholine release in the striatum at 15-45 min. This increase following intraperitoneal administration of beta-phenylethylamine (25 mg/kg) was not affected by locally applied SCH-23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine, 10 microM), a dopamine D(1) receptor antagonist, nor by raclopride (10 microM), a dopamine D(2) receptor antagonist. The increased release of acetylcholine induced by beta-phenylethylamine was suppressed by local infusion of tetrodotoxin (1 microM). In contrast, the extracellular acetylcholine level in the striatum was significantly decreased by local application of beta-phenylethylamine (10 and 100 microM) in the striatum via a microdialysis probe. The decrease was completely blocked by local co-application of raclopride (10 microM). The beta-phenylethylamine-induced decrease in striatal acetylcholine release was not affected by co-perfusion with SCH-23390 (10 microM). These results indicate that systemic administration of beta-phenylethylamine increases acetylcholine release, whereas locally applied beta-phenylethylamine decreases striatal acetylcholine release in freely moving rats. Furthermore, the dopaminergic system, through the dopamine D(2) receptor, is involved in the locally applied beta-phenylethylamine-induced decrease in acetylcholine in the striatum.

We previously reported that ciliary neurotrophic factor (CNTF) increased the serum-free cell survival of immortalized motor neuron-like cells (NSC-34), and addition of the exogenous ganglioside GalNAcβ4(Neu5Acα3)Galβ4GlcCer (GM2) facilitated cell survival together with CNTF. Moreover β 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity increased in NSC-34 cells cultured with CNTF. We now have examined whether CNTF-induced cell survival is associated with the collaboration between GM2 and the CNTF receptor (CNTF-R). Despite the presence of CNTF (50 ng/ml), anti-CNTF-R antibody caused cell death and prevented the up-regulation of GM2 synthase expression. The addition of GM2 (1 to 20 μM) abrogated the anti-CNTF-R antibody effect which shortened cell survival and blocked GM2 synthase activation. Use of [125I]CNTF showed the specificity of CNTF binding in NSC-34 cells in situ. GM2 produced a 5-fold increase in the CNTF binding affinity per cell but did not change the binding site number. The study by metabolic labeling with [1−14C]N-acetyl-D-galactosamine ([14C]GalNAc) showed that biosynthesized GM2 was involved in the immunoprecipitation of CNTF-R. These findings indicate that up-regulated GM2 synthesis induces functional conversion of CNTF-R to the activated state, in which it has affinity for CNTF. We conclude that GM2 is a bio-regulating molecule of CNTF-R in motor neurons.

Evidence is mounting to suggest a causal role of humoral immunity arising from antiglycosphingolipid (GSL) antibodies in a variety of neurological disorders. These disorders include the demyelinating and axonal forms of Guillain-Barre syndrome, multifocal motor neuropathy, chronic inflammatory demyelinating polyradiculoneuropathy, and IgM paraproteinemia. Many claims have been made regarding other neurological disorders, which should be carefully scrutinized for their validity, based on several criteria proposed in this review. These criteria include 1) characterization of the causative antigens and immunoglobulins, 2) correlation of the pathological lesions and clinical manifestation of the antigens, 3) establishment of animal models using pure GSLs as the antigens, 4) immunopathogenic mechanisms of the neurodenerative process, 5) mechanisms for the malfunctioning of blood–nerve barrier and the ensuing leakage of circulating antibodies into peripheral nerve parenchyma, and 6) the roles of anti-GSL antibodies that may cause humorally mediated nerve dysfunction and injury as well as interference with ion channel function at the node of Ranvier, where carbohydrate epitopes are located. Finally, the origin of the anti-GSL antibodies is discussed in light of the recent circumstantial evidence pointing to a molecular mimicry mechanism with infectious agents. With a better understanding of the immunopathogenic mechanisms, it will then be possible to devise rational and effective diagnostic and therapeutic strategies for the treatment of these neurological disorders. J. Neurosci. Res. 65:363–370, 2001. © 2001 Wiley-Liss, Inc.

We have examined whether ciliary neurotrophic factor (CNTF) can alter serum-free cell survival of immortalized motor neuron-like cells, which were established by fusing mouse neuroblasoma N18TG2 with mouse motor neurons. One of the cell lines, NSC-34 exhibited cell survival in the presence of CNTF. NSC-34 preserves the most characteristics of motor neurons, such as the formation of neuromuscular junctions on co-cultured myotube. GM2 ganglioside is characteristic of motor neurons, and expressed highly in NSC-34. When NSC-34 was cultured with exogenous GM2 ganglioside and CNTF, GM2 facilitated the cell survival effect of CNTF. In the addition, β 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity was enhanced up to 3.9-fold by culture in the presence of CNTF. GM2 might be a functional modulator of CNTF in motor neurons. It might be presented to cell surface by its enzyme activation, and become a signal of early stage, when CNTF rescues motor neurons.

The patients with Guillain-Barre Syndrome (GBS) subsequent to Campylobacter jejuni enteritis showed axonal degeneration and had IgG anti-GM1 antibody. The most frequently isolated C. jejuni from the patients was specific serotype of Penner's 19 in Japan. In the lipopolysaccharide (LPS) in C. jejuni of this serotype, the same oligosaccharide structure as GM1 ganglioside existed, suggesting the molecular mimicry between GM1 in nervous tissue and C. jejuni LPS. IgG anti-GM1 antibody may bind the nodes of Ranvier and axon terminals and causes degeneration of the motor axon. Some patients develop Fisher's syndrome following C. jejuni infection. C. jejuni strains from the patients who had IgG anti-GQ1b antibody in the acute phase had GQ1b epitope in their LPS, and the molecular mimicry between GQ1b in nervous tissue and an antecedent infectious agent was clarified.

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disease characterized by cerebellar ataxia associated to varying degrees with pyramidal signs, extrapyramidal signs, or peripheral amyotrophy. It is caused by unstable expansion of the CAG repeat in the MJD1 gene on chromosome 14q32.1. To determine how the neurodegenerative process in the central nervous system of patients with MJD correlates with the size of expanded CAG repeats in the MJD1 gene and other factors, we performed detailed quantitative analyses of findings of magnetic resonance imaging of the central nervous system of 21 patients with MJD of various ages and with various sizes of expanded CAG repeats. We found that atrophy of the brainstem and cerebellar vermis in MJD patients is closely correlated not only with the size of expanded CAG repeat in the MJD1 gene but also with patient age, which suggests that the neurodegenerative process in MJD is regulated by the size of expanded CAG repeats as well as by the patient age.

The growth inhibitory factor (GIF) is a new metallothionein (MT)-like protein that is downregulated in Alzheimer's disease (AD) brain. The biological function of GIF has not been fully clarified yet. We have raised an antibody to the synthetic polypeptide that is specific for rat GIF. The purified antibody reacted to recombinant GIF and native rat GIF but not to MT or maltose-binding protein. Using the antibody and GIF cDNA probe, we investigated changes of GIF and GIF mRNA by Western and Northern blotting techniques in rat brains after stab wounds. The levels of GIF and GIF mRNA began to increase 4 days postoperation, reached a maximum at 14-21 days and sustained the increased level at least through 28 days. While both glial fibrillary acidic protein (GFAP) and GIF were recognized in astrocytes, the increases of these 2 proteins after stab wounds showed different patterns. The results indicated that GIF could play an important role in the repair after brain damage and also produce new insights into the mechanism of gliosis investigated mainly from the viewpoint of GFAP.

Passive transfer of serum IgG or mononuclear cells from peripheral blood of a patient with paraneoplastic cerebellar degeneration (PCD) to rodents was carried out in order to examine the role of anti-Purkinje cell antibody (anti-Yo antibody) present in serum and cerebrospinal fluid of PCD patients. After a single injection of IgG into mouse brain, it was taken up by Purkinje cells and remained there for more than 36 h without Purkinje cell loss. Injection of PCD IgG together with complement or lipopolysaccharide-activated human macrophages or rat mononuclear cells into rat ventricles did not cause Purkinje cell loss. We also studied passive transfer of the PCD patient's lymphocytes to mice with severe combined immunodeficiency (SCID). We constructed a recombinant Yo fusion protein that has the leucine-zipper protein (Yo protein), the common epitope for anti-Yo antibody for immunizing mice, and that resulted in production of significant amounts of anti-Yo antibody. Spleen cells from these Yo protein immunized mice were injected intravenously or intracerebrally into naive mice that subsequently showed no neurological symptoms or loss of Purkinje cells. We conclude that the anti-Yo antibody, either in combination with or without complement or activated mononuclear cells, cannot be the sole cause of Purkinje cell loss.

About 85 % of patients with generalized myasthenia gravis (MG) have anti-nicotinic acetylcholine receptor (nAChR) antibodies in their sera (seropositive MG; SPMG). The other 15 % (seronegative MG; SNMG) are also considered to have antibody-mediated disease, but the nature of the antibodies in SNMG is not fully understood. We investigated the effect of sera from patients with MG on spontaneous muscle action potentials and acetylcholine (ACh)-induced potentials, and we examined the localization of epitopes recognized by SPMG sera or SNMG sera. SPMG sera and SNMG sera inhibited spontaneous muscle action potentials and ACh-induced potentials in the spinal-muscle co-culture system. However, spontaneous muscle action potentials and ACh-induced potentials in the neuromuscular junctions were strongly blocked by SPMG serum, whereas they were weakly blocked by SNMG serum. Both types of sera reacted strongly with the neuromuscular junctions in normal rat muscles, as shown by double immunostaining with serum and α-bungarotoxin. The SPMG epitope remained in the neuromuscular junctions, whereas that of SNMG disappeared after denervation of the sciatic nerve. Therefore, we suggest that the skeletal muscle weakness in SNMG may be due to an interaction with presynaptic neuromuscular transmission and nAChR.

Passive transfer of paraneoplastic cerebellar degeneration (PCD) IgG to rodents as well as active immunization with recombinant Yo fusion protein were tried in order to examine the roles of anti-Purkinje cell antibody (anti-Yo antibody) present in the sera and cerebrospinal fluid of patients with PCD in Purkinje cell loss, the hall mark of PCD pathology. On a single injection of PCD IgG to mouse brain, IgG was taken into Purkinje cells and remained there for more than 36 h without Purkinje cell loss. Injection of PCD IgG together with complement or lipopolysaccharide-activated human macrophages or rat mononuclear cells to rats ventricles did not cause Purkinje cell loss. We made a recombinant Yo fusion protein that has the leucine-zipper protein (Yo protein), the common epitope for anti-Yo antibody. Mice immunized with this Yo protein produced high titer antibody against it for more than 3 months, during which time neither neurological symptoms nor Purkinje cell loss occurred. The anti-Yo antibody, with or without complement or activated mononuclear cells, therefore could not be the sole cause of Purkinje cell loss.

We carried out a postmortem examination on two Japanese patients, 64- and 80-year-old men whose survival was prolonged with an artificial respirator. They had no family history of neuropsychiatric disorders and were suspected, clinically, as having a motor neuron disease that differed from amyotrophic lateral sclerosis (ALS). As well as upper and lower motor neuron impairment, they showed a variety of symptoms, such as sensory disturbances, hypohidrosis, impotence, ophthalmoparesis and/or atonic neurogenic bladder, and their protein content in cerebrospinal fluid was elevated markedly. Pathological examination revealed the following extensive nervous system involvement: (1) the upper and lower voluntary motor systems, including the IIIrd, IVth and VIth cranial nerve nuclei: (2) the reticular formation and its major afferent pathways; (3) the vestibulospinal and tectospinal systems; (4) the spinocerebellar system and the exteroceptive somatic afferent pathways; (5) the dentatorubral and pallidoluysian systems; and (6) the substantia nigra, locus ceruleus and intermediolateral and Onufrowicz's nuclei. Neither Bunina bodies, Lewy body-like hyaline inclusions nor ubiquitin immunoreactive skein-like structures were observed. The distribution of the lesions was quite different from that in patients with ALS and the other known related diseases. Recently, seven autopsied cases with clinical and histopathological similarities to our patients have been reported in Japan. Our conclusion is that our two and these seven patients should be classified as having a new motor neuron disease entity, which can be is differentiated from ALS.

Immunoreactivities of beta/A4 amyloid precursor protein (APP) and soluble derivative of APP (APPs) were determined in the hippocampus and the striatum of reserpinized rat brains. Significant decrease of APPs immunoreactivity was observed in the cytosolic fraction of hippocampus, but not of striatum, whereas APP immunoreactivity was found to be increased in the membrane fraction of hippocampus. These findings suggest that processing of APP in hippocampus may be regulated through the monoaminergic signal transduction system.

Central motor tract excitability was examined in 2 patients with Creutzfeldt-Jakob disease (CJD) and 8 normal subjects by measuring change in the motor evoked potential (MEP) by transcranial magnetic stimulation of the motor cortex after peripheral nerve stimulation. Conditioning stimulation of the median nerve at the wrist greatly increased MEP size (500–1700%) as compared to the size for normal subjects (140–380%) at conditioning-test (C-T) intervals of 30–60 msec for patient 1 and 40–70 msec for patient 2. Moreover, stimulation of the contralateral median nerve at the wrist and of the second and third digits also increased MEP size in the CJD patients; whereas, there was no increase in size in the normals. The time courses of abnormal MEP potentiation were very consistent with the course of the corresponding C reflex. One of the CJD patients had a normal size SEP, and neither patient showed hyperexcitability in SEP-recovery at C-T intervals of 20–60 msec at which there was marked MEP potentiation. These results indicate that there was hyperexcitability of the central motor tract in the CJD patients after the conditioning of muscle and cutaneous peripheral afferents and that it extended to the ipsilateral cortex on the conditioning side as well.

Protein kinase C (PKC) (alpha) and (beta) immunoreactivities were determined in the cytosolic and particulate fractions of the hippocampus and striatum after single and repetitive, intraperitoneal administration of reserpine. Significant decrease of PKC(alpha) immunoreactivities was observed in the particulate fractions of both striatum and hippocampus. Compared with the alteration of PKC(alpha), the decreased immunoreactivity of PKC(beta) was only observed in the particulate fraction of the hippocampus, associated with the increase in the cytosolic fraction. These findings suggest a novel mechanism regulating the distribution of PKC. The topographical selectivity in the present study may indicate the importance of the alteration of PKC(beta) in the pathophysiological mechanism in Alzheimer's disease.

An acid sialidase [EC 3.2.1.18], partially purified from human placenta by Con A-Sepharose adsorption and p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatographies, was activated by incubation at 37 degrees C. This activation showed both time and temperature dependencies, with the most effective activation observed at 37 degrees C in the pH range between 4.3 and 5.2. The influence of various protease inhibitors on its activation was investigated. Among the protease inhibitors tested, amastatin, an inhibitor of aminopeptidase A, significantly inhibited activation. The partially purified enzyme preparation contained aminopeptidase activity, which was inhibited by amastatin. Zinc ions inhibited either the activation of sialidase or the aminopeptidase activity in the enzyme preparation. These results suggest the possibility of participation of aminopeptidase function in the activation process of sialidase.

There is a strong association between Guillain-Barré syndrome (GBS) and Penner's serotype 19 (PEN 19) of Campylobacter jejuni. Sera from patients with GBS after C. jejuni infection have autoantibodies to GM1 ganglioside in the acute phase of the illness. Our previous work has suggested that GBS results from an immune response to cross-reactive antigen between lipopolysaccharide (LPS) of the Gram-negative bacterium and membrane components of peripheral nerves. To clarify the pathogenesis of GBS, we have investigated whether GM1-oligosaccharide structure is present in the LPS of C. jejuni (PEN 19) that was isolated from a GBS patient. After extraction of the LPS, the LPS showing the binding activity of cholera toxin, that specifically recognizes the GM1-oligosaccharide was purified by a silica bead column chromatography. Gas-liquid chromatography-mass spectrometric analysis has shown that the purified LPS contained Gal, GalNAc, and NeuAc, which are sugar components of GM1 ganglioside. 1H NMR methods [Carr-Purcell-Meiboom-Gill (CPMG), total correlation spectroscopy (TOCSY), and nuclear Overhauser effect spectroscopy (NOESY)] have revealed that the oligosaccharide structure [Gal beta 1-3 GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta] protrude from the LPS core. This terminal structure [Gal beta 1-3GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta] is identical to the terminal tetrasaccharide of the GM1 ganglioside. This is the first study to demonstrate the existence of molecular mimicry between nerve tissue and the infectious agent that elicits GBS.

An immunohistochemical method that uses two specific antisera-distinguishable myelin-associated glycoprotein (MAG) isoforms showed an expression of large MAG isoform (L-MAG) protein in the oligodendrocyte cytoplasms in the white matter around experimental cerebral infarcts produced by occlusion of the left middle cerebral artery in the rat. L-MAG protein also was detected in the white matter on the contralateral side. This protein appears prior to S-MAG protein in myelination and remyelination in the central and peripheral nervous systems, and is believed to function in myelin formation. Because L-MAG protein has been found in the oligodendrocyte cytoplasm only in the early development period, its appearance in this cytoplasm after ischemic insult is evidence of MAG regeneration.

Although the etiology of Alzheimer′s disease has not been elucidated yet, dysfunction and loss of synapses are believed to cause dementia. Recent studies suggest that the primary cause of the disease is closely related to the aberrant processing of the amyloid precursor protein (APP). To investigate the localization of APP at synaptic sites, we obtained synaptic plasma membrane and synaptic vesicles from rat brain. Enhanced chemiluminescence (ECL) western blot analysis using two specific polyclonal antibodies against APP revealed strong APP immunoreactivity in the synaptic plasama membrane, but not in the synaptic vesicle fraction. These data indicate that APP is localized at the synaptic plasma membrane and may play a role in physiological synaptic activity. Alternative localization or aberrant processing of APP at the synaptic site may cause impairment of synaptic function in Alzheimer′s disease.

The nosological position of Bickerstaff's brain stem encephalitis (BBE) has yet to be established, and its etiology is not clear. Because anti-GQ1b antibody frequently occurs in patients with Fisher's syndrome (FS) and there are clinical similarities between FS and BBE, we investigated anti-ganglioside antibodies in sera from 3 BBE patients who had transient long tract signs in addition to acute ophthalmoplegia and cerebellar-like ataxia in order to clarify the etiology and nosological position of BBE. High IgG anti-GQ1b antibody titers were present in all 3 sera samples but decreased with the clinical course of the illness. In contrast, no anti-GQ1b antibody was found in sera from patients with other neurologic diseases which were able to produce transient brain stem disturbance: multiple sclerosis, neuro-Behçet's disease, brain stem infarction, herpes simplex virus encephalitis, and Wernicke's encephalopathy. The finding that BBE and FS shared common autoantibody suggests that autoimmune mechanism common to FS is likely in BBE, and that both conditions represent a distinct disease with a wide spectrum of symptoms that include ophthalmoplegia and ataxia.

Human growth inhibitory factor (GIF) is a new metallothionein-related molecule whose expression is markedly reduced in Alzheimer's disease (AD) brain. We have recently isolated a full-length cDNA for human GIF that has a striking homology to metallothioneins (MTs). As an initial step to better understanding of the biological functions of GIF, we have isolated a full-length cDNA for rat GIF. Comparison of the predicted amino acid sequence with that of human GIF revealed a strikingly high homology (84% identity). Rat GIF cDNA also showed a striking homology to rat MT-1 and MT-II (66% and 62% identities on amino acid sequences, respectively). All cysteine residues were conserved among rat GIF, human GIF and MTs, indicating that cysteine residues play an important function in these molecules. Compared to mammalian MTs, there were 3 bp and 12 bp insertions near the amino-terminal and carboxy-terminal regions in the rat GIF. The rat GIF mRNA was found to be expressed exclusively in the central nervous system, being expressed predominantly in rat cortical astrocytes in primary culture. Although the rat GIF mRNA expression was low during the fetal stage, a dramatic increase of the rat GIF mRNA expression was demonstrated during the postnatal period of 10-17 days. These results indicate that transcriptional regulation of the rat GIF gene is quite different from that of MTs despite its strikingly high homology with MTs.

Smoking a cigarette relieved symptoms in 6 patients with early-onset Parkinson's disease. In these patients smoking reduced tremor, rigidity, bradykinesia, and gait disturbance including frozen gait. These effects lasted for about 10–30 min, and relieved parkinsonian symptoms in the off-period. Nicotine chewing gum had a lesser effect. Nicotine is thought to activate the nigrostriatal dopaminergic pathway and increase the release of dopamine in the striatum, and this can explain the effects of smoking in these patients.

We earlier reported cases of 2 patients with severe acute Guillain-Barre syndrome (GBS) associated with high-IgG anti-GD1a antibody titer. We now have investigated the autoantibody against GD1a or GM1 in 37 GBS patients using the enzyme-linked immunosorbent assay and have found a statistically significant association between IgG anti-GD1a antibody and the severity of the disease (need of a respirator for more than 1 month and a poor functional prognosis 3 months after neurologic onset). An autopsy which showed severe GBS associated with IgG anti-GD1a antibody produced the following findings: (1) severe axonal degeneration and segmental demyelination of peripheral nerves; (2) lymphocytic infiltration; and (3) marked central chromatolysis of the lower motoneurons.

In order to clarify the significance of subpial β A 4 peptide deposits (SPβPD), we examined the brains of 160 consecutive autopsied cases (average age 84.4 ± 7.7 years) with or without dementia of the Alzheimer type (DAT) pathologically and immunohistochemically. SPβPD and amyloid angiopathy (AA) showed a significant positive correlation in their severities, both in the DAT and non-DAT groups. AA was present in most cases with SPβPD, but was absent in all cases without SPβPD. Our results suggest that SPβPD and AA would be the related lesions, and that SPβPD would be formed previous to AA.

The perivascular macrophages in the brain are thought to be derived from bone marrow precursor cells. Results presented here demonstrate that immature macrophages obtained from nonadherent spleen cell populations can adhere to cerebrovascular endothelial cell (EC) monolayers and proliferate. The proliferation of these cells can be stimulated by either purified murine granulocyte-macrophage colony-stimulating factor (GM-CSF) or EC conditioned medium but not by IL-3. No proliferation of the GM-CSF- or IL-3-dependent murine cell line IC-2 was observed in the presence of EC conditioned medium. Macrophage-like cells could also be derived from murine bone marrow cells but inhibited by anti-macrophage-CSF (M-CSF or CSF-1). The capacity of EC conditioned medium to induce the proliferation of macrophage-like cells from the spleen is therefore not due to the release of GM-CSF but CSF-1. In concomitant experiments using mature macrophages incubated on EC monolayers, no proliferation was observed. These findings suggest that the growth of perivascular macrophages in the brain may be stimulated by cerebrovascular EC.

Circulating autoantibody to a 48-kD nuclear protein in neurons and astrocytes of the human and bovine cerebrum were present in the serum of a demented patient with an autoimmune disorder. Other human visceral organs, dorsal root ganglion cells, neuroblastoma and glioblastoma cell lines, and rat cerebrum did not react with the patient's serum. No sera from age-matched controls, including those with Alzheimer's disease, reacted with the 48-kD protein. Only the mature neurons and astrocytes of humans and some mammals express the 48-kD protein. This antibody may be responsible for the patient's demented condition.

Amyloid beta protein (beta/A4) is deposited in senile plaques of patients with Alzheimer's disease. This protein is derived from a larger membrane-associated protein, termed amyloid precursor protein (APP). The constitutive processing of APP occurs at the central portion of beta/A4, resulting in the release of large N-terminal peptides. We have purified these peptides from the culture medium of cDNA-transfected COS-1 cells. Some of the isoforms contain the Kunitz-type protease inhibitor (KPI) domain and strongly inhibit trypsin, chymotrypsin and plasmin, but do not inhibit kallikrein, prolyl endopeptidase or granzyme A. The peptides also do not inhibit cysteine proteases such as cathepsin B or calpain. Soluble APPs lacking the KPI domain fail to inhibit any of these proteases. The results indicate that the KPI domain in soluble APPs has protease inhibitory activity against certain serine proteases.

The extracellular accumulation of amyloid beta proteins (Abetas) in neuritic plaques is one of the hallmarks of Alzheimer's disease (AD). The binding of Abetas to extracellular membranes (ECMs) is a critical step in developing AD. Abetas bind to many biomolecules, including lipids, proteins, and proteoglycans (PGs). PGs play several roles in amyloid formation, including promoting the aggregation of Abetas into insoluble amyloid fibrils, which contributes to the increased neurotoxicity of Abetas. Although Abetas readily self-aggregate to form amyloid fibrils in vitro, their binding to PGs and heparin enhances amyloid aggregation and fibril formation. The sulfate moiety in glycosaminoglycans (GAGs), the carbohydrate portion of PGs, is necessary for the formation of amyloid fibrils; no fibrils are observed in the presence of hyaluronic acid (HA), a nonsulfated GAG. PGs and Abetas are known to colocalize in senile plaques (SPs) and neurofibrillary tangles (NFTs) in the AD brain. The binding site of PGs to Abetas has been identified in the 13-16-amino-acid region (His-His-Gln-Lys) of Abetas and represents a unique target site for inhibition of amyloid fibril formation; His13 in particular is an important residue critical for interaction with GAGs. The sulfate moieties of GAGs play a critical role in the binding to Abetas and enhance Abeta fibril formation. Low-molecular-weight heparins (LMWHs) can reverse the process of amyloidosis to inhibit fibril formation by blocking the formation of beta-plated structures, suggesting a possible therapeutic approach using LMWHs to interfere with the interaction between PGs and Abetas and to arrest or prevent amyloidogenesis.

In previous studies, we discovered a growth inhibitory factor (GIF) that was abundant in normal human brain, but greatly reduced in Alzheimer's disease (AD) brain. Molecular cloning of a full-length cDNA for human GIF revealed that the GIF had striking homology to metallothioneins. Furthermore, it was determined that the GIF gene was on chromosome 16, as are the metallothionein genes. GIF, in contrast to metallothioneins, was found to be expressed exclusively in the nervous system. The GIF protein produced by Escherichia coli harboring the GIF cDNA in a prokaryotic expression vector inhibited the growth of neonatal rat cortical neurons. These results indicate that GIF is a new member of the metallothionein family with distinct tissue-specific expression and functions. Northern blot analysis revealed that expression of the GIF mRNA is drastically decreased in AD brains. The result raises the possibility that down-regulation of the GIF gene in AD brain plays an important role in the pathogenesis of AD.

We report cases of 2 patients with pure motor Guillain--Barre syndrome of explosive onset who required mechanical ventilation for more than 2 months. Their electrophysiologic findings and poor clinical recoveries suggested severe axonal degeneration involving the motor nerves. Enzymelinked immunosorbent assay and thin-layer chromatogram-immunostaining showed the sera of both patients had high IgG antibody titer against GD1a ganglioside. Their titers decreased with the clinical course of the illness. GD1a as well as GM1, appears to be the target pathogenic antigen in motor axon disorders. Elevated IgG anti-GD1a antibody titer may prove useful for predicting severe GBS. © 1992 John Wiley & Sons, Inc.

The nucleus basalis of Meynert (nbM) was lesioned by injection of ibotenic acid, in 200 g male Wistar rats. The rats were killed 1, 3, 7 or 21 days after surgery, the brains were removed and the prefrontal cortices were subjected to immunohistochemical and Western blot analysis for the expression of glial fibrillary acidic protein (GFAP). In some rats, vehicle was injected into the nbM and in others 6-hydroxydopamine (6-OHDA) was injected into the ventral tegmental area (VTA). Quantitative Western blot analysis revealed significantly greater immunoreactivity for GFAP in the prefrontal cortex of nbM-lesioned rats. Immunohistochemical examination revealed fibrous and hypertrophic GFAP-positive astrocytes even one day after surgery, and this reaction was stronger at 3 days after surgery. After this peak, GFAP-immunoreactivity of the astrocytes decreased from 7 days to 21 days. In contrast, GFAP-positive astrocytes were not observed in the brains of vehicle-injected or VTA-lesioned rats, even 21 days after surgery. The present results indicate that cortical astrocytes respond to cholinergic deafferentation. In addition, our findings provide new insights into the abnormalities of cortical glial cells after cholinergic deafferentation in Alzheimer's disease.