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H Tomimitsu

Publications and source records attributed to H Tomimitsu.

9 recordsLinked to original sources
PubMed2006

Early clinical signs and imaging findings in Gerstmann-Sträussler-Scheinker syndrome (Pro102Leu).

OBJECTIVE: To determine the clinical and radiologic features of Gerstmann-Sträussler-Scheinker syndrome caused by Pro102Leu mutation in PRNP (GSS102). METHODS: The authors report 11 patients (nine families) with clinically and radiologically diagnosed GSS102. RESULTS: All patients showed mild gait disturbance, dysesthesia and hyporeflexia of the lower legs, and truncal ataxia, and 9 of 11 patients showed proximal leg muscle weakness during the early stage of the disease. Dementia was not a main symptom during the early stage. Brain MRI and EEG abnormalities were not prominent initially. SPECT (N-isopropyl-p-[(123)I]iodoamphetamine) analyzed by the three-dimensional stereotactic surface projection (SSP) method detected abnormalities in five patients early during the course of the illness. SPECT findings showed diffusely decreased cerebral blood flow, demonstrated by a mosaic pattern, with the lowest perfusion noted in the occipital lobes. In contrast, blood flow to the cerebellum was preserved. These studies suggested sites of pathology in GSS102, with the main lesions probably located in the cerebrum and the spinal cord (posterior horn and spinocerebellar tract) instead of the cerebellum. CONCLUSIONS: Key features for early diagnosis of Gerstmann-Sträussler-Scheinker syndrome caused by Pro102Leu mutation in PRNP (GSS102) are truncal ataxia, dysesthesia and hyporeflexia of the lower legs, and mild dysarthria. Normal cerebellar MRI and abnormal cerebral SPECT findings are characters of early GSS102.

Amyloid↗
PubMed2006

IgM-containing fraction suppressed voltage-gated potassium channels in acquired neuromyotonia.

OBJECTIVES: Acquired neuromyotonia (ANM) is an autoimmune disorder caused by antibodies to voltage-gated potassium channels (VGKC). Previously, we reported a patient with immunoglobulin M (IgM), instead of immunoglobulin G (IgG), anti-VGKC antibody. The purpose of this study was to determine the function of IgM-containing fraction in ANM patients. MATERIALS AND METHODS: We determined whether anti-VGKC antibodies in the IgG or IgM-containing fractions suppressed outward potassium current (OKC) using the patch clamp method in three patients with ANM. Whole sera from all patients suppressed OKCs. RESULT: Only the purified IgG, not the IgM-containing fractions from two patients suppressed VGKCs, whereas in a patient with IgM anti-VGKC antibody, only the IgM-containing fractions, not the IgG-containing fractions suppressed VGKCs. CONCLUSION: Anti-VGKC antibodies belonging to the IgM subclass should be determined in seronegative ANM patients.

Antibody Formation↗
PubMed2004

Distal myopathy with rimmed vacuoles (DMRV): new GNE mutations and splice variant.

Study of the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene (GNE) revealed that almost all cases of distal myopathy with rimmed vacuoles were caused by GNE mutations. Seven new mutations were identified, including M712T, which is the most common mutation in Jewish hereditary inclusion body myopathy. In addition, a splice-variant characteristic of the skeletal muscle was found, whereas the difference of the expression level between GNE-mutated and -nonmutated patients was not apparent.

Adolescent↗
PubMed2004

A Japanese patient with distal myopathy with rimmed vacuoles: missense mutations in the epimerase domain of the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene accompanied by hyposialylation of skeletal muscle glycoproteins.

Hereditary inclusion body myopathy and distal myopathy with rimmed vacuoles are both caused by mutations of the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. Here we report a Japanese patient with compound heterozygous missense mutations in the epimerase domain of GNE gene, 89 G to C and 578 A to T. Biochemical analysis demonstrated decreased reactivity of skeletal muscle glycoproteins with the lectins recognizing sialic acid residues. The results suggest that hyposialylation of glycoproteins may be involved in the pathogenesis of muscle dysfunction in this patient.

Adult↗
PubMed2002

Distal myopathy with rimmed vacuoles: novel mutations in the GNE gene.

The authors present three novel missense mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene, the causative gene for hereditary inclusion body myopathy, in Japanese patients with distal myopathy with rimmed vacuoles. Seven out of nine patients had homozygous V572L mutation, one was a compound heterozygote with C303V and V572L mutations, and the remaining patient bore homozygous A631V mutation.

Adolescent↗
PubMed2001

[Episodic ataxia type 2].

Episodic ataxia type 2 is an autosomal dominant paroxysmal cerebellar ataxia characterized by acetazolamide-responsive recurrent attacks with interictal nystagmus. This disease is caused by mutations (mainly truncating mutation) within the alpha1(A) subunit of P/Q type voltage-dependent calcium channel gene, CACNA1A. Further researches would establish the genotype/phenotype correlation and clarify the mechanism of this disorder.

English Abstract↗
PubMed1999

Involvement of the spinal posterior horn in Gerstmann-Sträussler-Scheinker disease (PrP P102L).

OBJECTIVE: The authors studied the pathomechanisms of the characteristics associated with Gerstmann-Sträussler-Scheinker disease (GSS). BACKGROUND: GSS, associated with a missense mutation at codon 102 of the prion protein (PrP) gene (GSS102), is a hereditary disorder that presents with progressive ataxia and dementia, and is characterized by the loss of deep tendon reflexes and painful dysesthesias of the legs in its early stage. METHODS: The authors conducted immunohistochemical studies of the spinal cord and peripheral nervous system in one of two patients from a Japanese family with GSS102 in comparison with patients with GSS105. RESULTS: The authors found intense PrP immunoreactivities mainly in the posterior horn of the spinal cord, but not in the dorsal root ganglia or peripheral nerves. In addition to PrP amyloid plaques, synaptic-type, fine granular PrP deposits were distributed in the spinal posterior horns. In contrast to the GSS102 patient, the spinal cords of the GSS105 patients showed no granular PrP deposits. CONCLUSIONS: The PrP abnormalities in synaptic structures of the spinal posterior horn may cause synaptic dysfunction that leads to loss of deep tendon reflexes and painful dysesthesias in patients with GSS102.

Adult↗
PubMed1998

Unmyelinated nerve fibers in sural nerve in pure autonomic failure.

We examined sural nerve biopsy specimens from 7 patients with pure autonomic failure (PAF). The mean unmyelinated nerve fiber density in these patients was 40% less than in age-matched controls. Increased numbers of clusters of collagen pockets not containing unmyelinated axons were the most prominent finding in PAF. This appears to reflect recent dropout of a group of sympathetic efferents and suggests grouping of unmyelinated fibers by modality at the level of the sural nerve trunk.

Aged↗