We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sc... more We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sclerosis (ALS)-related genes in Japanese ALS patients. We designed a multiplex, polymerase chain reaction-based primer panel to amplify the coding regions of the 28 ALS-related genes and sequenced DNA samples from 257 Japanese ALS patients using an Ion Torrent PGM sequencer. We also performed exome sequencing and identified variants of the 28 genes in an additional 251 ALS patients using an Illumina HiSeq 2000 platform. We identified the known ALS pathogenic variants and predicted the functional properties of novel nonsynonymous variants in silico. These variants were confirmed by Sanger sequencing. Known pathogenic variants were identified in 19 (48.7%) of the 39 familial ALS patients and 14 (3.0%) of the 469 sporadic ALS patients. Thirty-two sporadic ALS patients (6.8%) harbored 1 or 2 novel nonsynonymous variants of ALS-related genes that might be deleterious. This study reports the fi...
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, Jan 27, 2016
Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nico... more Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction, which leads to muscle weakness. We developed a fusion protein, AChR-Fc, as a novel therapeutic biomolecule for patients with MG and examined its efficacy. AChR-Fc was expressed by Chinese hamster ovary cells and purified. We examined the neutralizing activity and cellular cytotoxicity of AChR-Fc using anti-AChR antibody-producing hybridoma cells and serum samples from 16 patients with MG. The effects of AChR-Fc in vivo were also examined using rat MG models. AChR-Fc bound to anti-AChR antibodies and exhibited cytotoxicity against patient-derived antibody-producing B cells. Additionally, a dose-dependent improvement in the clinical signs of disease was observed in a rat MG model. AChR-Fc can diminish signs of MG by neutralizing anti-AChR antibodies and enhancing cytotoxicity against autoantibody-producing B cells. Thus, AC...
To identify the target molecules of chronic inflammatory demyelinating polyneuropathy (CIDP), we ... more To identify the target molecules of chronic inflammatory demyelinating polyneuropathy (CIDP), we used proteomic-based approach in the extracted proteins from porcine cauda equina. Two of 31 CIDP patients had markedly elevated serum autoantibodies against vinculin, a cell adhesion protein. Both of the patients with anti-vinculin antibodies had similar clinical manifestation, which are compatible with those of "typical" CIDP. Immunocytochemistry showed that vinculin was stained at the myelin sheath of the sciatic nerves by serum samples. Our results suggest that vinculin is a possible immunological target molecule in a subpopulation of typical CIDP patients.
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, Jan 16, 2016
To determine the utility of the Awaji criteria in diagnosing amyotrophic lateral sclerosis (ALS) ... more To determine the utility of the Awaji criteria in diagnosing amyotrophic lateral sclerosis (ALS) and to propose a novel modification so as to enhance sensitivity based on results of individual patient data (IPD). Individual patient data were available from 8 studies comparing the diagnostic accuracy of Awaji and revised El Escorial (rEEC) criteria. The sensitivity of a novel updated Awaji criteria, incorporating a "probable-laboratory supported" category, was also tested. Individual patient data were available from 1086 patients, consisting of 881 ALS and 205 patients with disorders mimicking ALS. Summary sensitivities based on random effects logistic regression modelling disclosed a higher sensitivity of the Awaji criteria (0.70, 95% confidence interval [CI] 0.51-0.83) and updated Awaji criteria (0.73, 95% CI 0.56-0.85) when compared to rEEC (0.58, 95% CI 0.48-0.68). Paired analysis revealed higher sensitivities of Awaji criteria in 4 studies, and of updated Awaji criteri...
Machado-Joseph disease is one of the most common hereditary spinocerebellar degenerative disorder... more Machado-Joseph disease is one of the most common hereditary spinocerebellar degenerative disorders with a wide range of clinical manifestations. Pathology studies have shown mild to moderate loss of anterior horn cells and, in terms of spinal pathology, Machado-Joseph disease is regarded as a type of lower motoneuron disease. Muscle cramps are often associated with lower motoneuron disorders, but features of cramps in Machado-Joseph disease patients have never been studied. We investigated the incidence and nature of muscle cramps in Machado-Joseph disease patients, the excitability properties of motor axons [strength-duration time constant (tau(SD)), threshold electrotonus, refractoriness and supernormality] using threshold tracking and the effects of mexiletine hydrochloride on those cramps. Of 20 consecutive patients, 16 (80%) had frequent, severe muscle cramps in the legs, trunk or arms that disturbed their daily activities. The frequency of pathological muscle cramps was similar to that for patients with amyotrophic lateral sclerosis (68%) and higher than those for patients with spinal muscular atrophy (33%) or peripheral axonal neuropathy (24%). Threshold-tracking studies showed that tau(SD), which in part reflects Na(+) conductance at the resting membrane potential, was significantly greater in the Machado-Joseph disease patients than in normal subjects; severe muscle cramps were associated with a longer tau(SD). Threshold electrotonus, refractoriness and supernormality were not significantly different between Machado-Joseph disease patients and normal subjects. Eight Machado-Joseph disease patients with severe cramps, who received mexiletine treatment, experienced nearly complete relief with a partial normalization of tau(SD) (P = 0.08). Muscle cramps are a very frequent and disabling factor in Machado-Joseph disease. Pathological muscle cramps responded well to mexiletine treatment, and this is consistent with the hypothesis that they are caused by an increase in persistent Na(+) conductance, possibly associated with axonal regeneration or collateral sprouting.
We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sc... more We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sclerosis (ALS)-related genes in Japanese ALS patients. We designed a multiplex, polymerase chain reaction-based primer panel to amplify the coding regions of the 28 ALS-related genes and sequenced DNA samples from 257 Japanese ALS patients using an Ion Torrent PGM sequencer. We also performed exome sequencing and identified variants of the 28 genes in an additional 251 ALS patients using an Illumina HiSeq 2000 platform. We identified the known ALS pathogenic variants and predicted the functional properties of novel nonsynonymous variants in silico. These variants were confirmed by Sanger sequencing. Known pathogenic variants were identified in 19 (48.7%) of the 39 familial ALS patients and 14 (3.0%) of the 469 sporadic ALS patients. Thirty-two sporadic ALS patients (6.8%) harbored 1 or 2 novel nonsynonymous variants of ALS-related genes that might be deleterious. This study reports the fi...
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, Jan 27, 2016
Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nico... more Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction, which leads to muscle weakness. We developed a fusion protein, AChR-Fc, as a novel therapeutic biomolecule for patients with MG and examined its efficacy. AChR-Fc was expressed by Chinese hamster ovary cells and purified. We examined the neutralizing activity and cellular cytotoxicity of AChR-Fc using anti-AChR antibody-producing hybridoma cells and serum samples from 16 patients with MG. The effects of AChR-Fc in vivo were also examined using rat MG models. AChR-Fc bound to anti-AChR antibodies and exhibited cytotoxicity against patient-derived antibody-producing B cells. Additionally, a dose-dependent improvement in the clinical signs of disease was observed in a rat MG model. AChR-Fc can diminish signs of MG by neutralizing anti-AChR antibodies and enhancing cytotoxicity against autoantibody-producing B cells. Thus, AC...
To identify the target molecules of chronic inflammatory demyelinating polyneuropathy (CIDP), we ... more To identify the target molecules of chronic inflammatory demyelinating polyneuropathy (CIDP), we used proteomic-based approach in the extracted proteins from porcine cauda equina. Two of 31 CIDP patients had markedly elevated serum autoantibodies against vinculin, a cell adhesion protein. Both of the patients with anti-vinculin antibodies had similar clinical manifestation, which are compatible with those of "typical" CIDP. Immunocytochemistry showed that vinculin was stained at the myelin sheath of the sciatic nerves by serum samples. Our results suggest that vinculin is a possible immunological target molecule in a subpopulation of typical CIDP patients.
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, Jan 16, 2016
To determine the utility of the Awaji criteria in diagnosing amyotrophic lateral sclerosis (ALS) ... more To determine the utility of the Awaji criteria in diagnosing amyotrophic lateral sclerosis (ALS) and to propose a novel modification so as to enhance sensitivity based on results of individual patient data (IPD). Individual patient data were available from 8 studies comparing the diagnostic accuracy of Awaji and revised El Escorial (rEEC) criteria. The sensitivity of a novel updated Awaji criteria, incorporating a "probable-laboratory supported" category, was also tested. Individual patient data were available from 1086 patients, consisting of 881 ALS and 205 patients with disorders mimicking ALS. Summary sensitivities based on random effects logistic regression modelling disclosed a higher sensitivity of the Awaji criteria (0.70, 95% confidence interval [CI] 0.51-0.83) and updated Awaji criteria (0.73, 95% CI 0.56-0.85) when compared to rEEC (0.58, 95% CI 0.48-0.68). Paired analysis revealed higher sensitivities of Awaji criteria in 4 studies, and of updated Awaji criteri...
Machado-Joseph disease is one of the most common hereditary spinocerebellar degenerative disorder... more Machado-Joseph disease is one of the most common hereditary spinocerebellar degenerative disorders with a wide range of clinical manifestations. Pathology studies have shown mild to moderate loss of anterior horn cells and, in terms of spinal pathology, Machado-Joseph disease is regarded as a type of lower motoneuron disease. Muscle cramps are often associated with lower motoneuron disorders, but features of cramps in Machado-Joseph disease patients have never been studied. We investigated the incidence and nature of muscle cramps in Machado-Joseph disease patients, the excitability properties of motor axons [strength-duration time constant (tau(SD)), threshold electrotonus, refractoriness and supernormality] using threshold tracking and the effects of mexiletine hydrochloride on those cramps. Of 20 consecutive patients, 16 (80%) had frequent, severe muscle cramps in the legs, trunk or arms that disturbed their daily activities. The frequency of pathological muscle cramps was similar to that for patients with amyotrophic lateral sclerosis (68%) and higher than those for patients with spinal muscular atrophy (33%) or peripheral axonal neuropathy (24%). Threshold-tracking studies showed that tau(SD), which in part reflects Na(+) conductance at the resting membrane potential, was significantly greater in the Machado-Joseph disease patients than in normal subjects; severe muscle cramps were associated with a longer tau(SD). Threshold electrotonus, refractoriness and supernormality were not significantly different between Machado-Joseph disease patients and normal subjects. Eight Machado-Joseph disease patients with severe cramps, who received mexiletine treatment, experienced nearly complete relief with a partial normalization of tau(SD) (P = 0.08). Muscle cramps are a very frequent and disabling factor in Machado-Joseph disease. Pathological muscle cramps responded well to mexiletine treatment, and this is consistent with the hypothesis that they are caused by an increase in persistent Na(+) conductance, possibly associated with axonal regeneration or collateral sprouting.
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Papers by Satoshi Kuwabara