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Hirokazu Furuya

Publications and source records attributed to Hirokazu Furuya.

31 records · Page 2Linked to original sources
PubMed2003

A novel mutation (L250V) in the presenilin 1 gene in a Japanese familial Alzheimer's disease with myoclonus and generalized convulsion.

This study reports a novel presenilin 1 (PS1) gene mutation in a Japanese family with Alzheimer's disease (AD). Two patients developed progressive memory disorder with disorientation around 50 years of age and showed myoclonus with frequent tonic-clonic seizures several years later. Direct sequencing of the proband's PS1 gene revealed a novel mis-sense mutation (leucine-to-valine at residue 250 (L250V)). This mutation was found in both patients, but not in a normal family member or normal Japanese control subjects. Thus, L250V is a novel PS1 gene mutation responsible for familial AD (FAD) in Japan.

Alzheimer Disease↗
PubMed2003

Dysferlin expression in tubular aggregates: their possible relationship to endoplasmic reticulum stress.

Dysferlin is a newly identified sarcolemmal protein related to Miyoshi myopathy and limb-girdle muscular dystrophy. Although its function is still unknown, it is inferred from the presence of C2 domains and a transmembrane domain in its sequence that dysferlin may be expressed or located not only at the sarcolemma but also in other membranous organelles to interact with Ca(2+). Tubular aggregates (TAs) are derived from sarcoplasmic reticulum (SR) and found in various myopathies, especially in those related to disturbed intra-sarcoplasmic Ca(2+) homeostasis. To clarify the expression of dysferlin in TAs and the relationship among TA formation, dysferlin expression, and endoplasmic reticulum (ER) stress, we examined the expression of dysferlin and other sarcolemmal proteins by immunohistochemistry in 12 muscle biopsy specimens with TAs from 11 cases of periodic paralysis and 1 case of myalgia/cramps syndrome. Moreover, the expression of glucose-regulated protein 78 (GRP78) and GRP94, which are up-regulated under ER stress, was also examined by immunohistochemistry and immunoblotting. TAs showed strong expression of dysferlin. GRP78 and GRP94 were also intensely expressed in TAs. Total amounts of GRP78 and GRP94 were significantly increased in muscles with TAs compared with normal controls. These results indicate that muscles with TAs seem to be under ER stress, probably resulting from disturbed intra-sarcoplasmic Ca(2+) homeostasis. Strong expression of dysferlin in TAs suggests the possibility that it is located not only at the sarcolemma but also in the SR, at least in the pathological conditions.

Adolescent↗
PubMed2003

Involvement of cathepsin B in the motor neuron degeneration of amyotrophic lateral sclerosis.

Abnormal proteolysis may be involved in the motor neuron degeneration of amyotrophic lateral sclerosis (ALS). Although several studies of the ubiquitin-proteasome system in ALS have been reported, the endosome-lysosome system has not been investigated in detail. To clarify the association of neurodegeneration with the endosome-lysosome system in ALS, we examined the pathological expression of cysteine proteases such as cathepsins B, H and L and an aspartate protease, cathepsin D, in the anterior horns of 15 ALS cases and 5 controls. In the ALS cases, cathepsin B immunoreactivity was preferentially decreased in the lateral parts of the anterior gray horns compared with the controls. Its immunoreactivity was increased in the cytoplasm of both shrunken and pigmented neurons but was weak in the neurons containing Bunina bodies. In addition, reactive astrocytes were also immunolabeled with cathepsin B. Cathepsin H and cathepsin L were detected in the cytoplasm of a small number of shrunken and pigmented neurons. Cathepsin D immunoreactivity was strong in the cytoplasm of all motor neurons. The immunoreactivity of cathepsins H, L and D was not significantly different between control and ALS cases. Western blot analysis showed that the 25-kDa activated form of cathepsin B was down-regulated in ALS. Our results suggest that cathepsin B is involved in the motor neuron degeneration in ALS.

Aged↗
PubMed2003

[A case of severe parkinsonism induced by failure of ventriculo-peritoneal shunt for aqueductal stenosis].

A 26-year-old man, who had received a ventriculo-peritoneal shunt for obstructive hydrocephalus after possible encephalitis, complained of disturbance of upward gaze and difficulty in movement seven months after the shunt implantation. One month later, neurological examination revealed upward gaze paresis and rigidity of all four limbs, but the neuroimaging studies revealed no ventricular dilatation. His symptoms deteriorated, and tremor of the extremities appeared. He was admitted to our hospital 10 months after the shunt implantation. He developed akinetic mutism soon after admission. Cerebrospinal fluid protein was elevated (62 mg/dl). At that time, the shunt reservoir was found to be insufficiently filled, and neuroimaging showed dilatation of the lateral and third ventricles with no dilatation of the fourth ventricle. A neuroendoscopic third ventriculostomy with removal of the previous shunt system gradually resolved the parkinsonism within two months, and the patient became capable of walking. The dilatation of the ventricles improved on neuroimaging. The present report suggests that shunt malfunction should be suspected when parkinsonism occurs in patients who have undergone a shunt placement, even though hydrocephalus on neuroimaging is not observed.

Adult↗
PubMed2002

Increased IL-13 but not IL-5 production by CD4-positive T cells and CD8-positive T cells in multiple sclerosis during relapse phase.

In the present study, we flow cytometrically analyzed the intracellular production of interleukin (IL)-5 and IL-13 in peripheral blood CD4(+) and CD8(+) T cells from patients with multiple sclerosis (MS), human T-lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and healthy controls. IL-13-producing T cells were significantly increased in both T cell subsets in MS at relapse, markedly in the conventional form of MS and modestly in the optocospinal form of MS, and returned to normal at remission. However, IL-5-producing T cells did not vary regardless of clinical phase or type. HAM/TSP showed no significant change in the number of IL-5- and IL-13-producing cells. A distinct profile of IL-13 and IL-5 production by disease and by phase of MS suggests an active involvement of these type 2 cytokines in central nervous system (CNS) inflammation.

Adult↗
PubMed2002

Paradoxical lateralization of parasagittal spikes revealed by back averaging of EEG and MEG in a case with epilepsia partialis continua.

Our aim was to localize the generator site of parasagittal epileptiform discharges in a patient with epilepsia partialis continua (EPC) in the right leg. We examined a 32-year-old woman with EPC whose conventional EEG did not show any epileptic discharge. We performed the jerk-locked back averaging (JLA) of EEG and magnetoencephalography (MEG) to localize the dipole source of sharp transients. The myoclonic discharges in the right soleus muscle were used as a trigger pulse. JLA revealed consistent EEG and MEG sharp transients that coincided consistently and constantly preceded the myoclonic jerks. JLA of EEG demonstrated sharp waves paradoxically distributed over the vertex and right hemisphere. However, the estimated dipoles of MEG were localized in a restricted area in the primary leg motor area in the left hemisphere, which was closely located in the abnormal lesion on the brain MRI. JLA of MEG is considered to be a useful non-invasive method for localizing the epileptogenic area in EPC even when paradoxical lateralization of electroencephalographic discharges was noted.

Action Potentials↗
PubMed2002

A patient with delayed posthypoxic demyelination: a case report of hyperbaric oxygen treatment.

A 62-year-old man who developed akinetic mutism with delayed white matter demyelination after hypoxia was treated with hyperbaric oxygen (HBO). HBO in the subacute period markedly improved the patient's activity in daily life, cognitive function and organization on EEG. 1H-MRS showed a recovery of aerobic metabolism of the neurons. However, dementia and cerebral atrophy slowly progressed despite HBO treatment. Thus, HBO had a beneficial effect on the activity of depressed neurons but did not improve the prognosis.

Atrophy↗
PubMed2002

High incidence of subclinical peripheral neuropathy in myelitis with hyperIgEaemia and mite antigen-specific IgE (atopic myelitis): an electrophysiological study.

OBJECTIVE: To study subclinical involvement of the peripheral nerves in myelitis with hyperIgEaemia and mite antigen-specific IgE (atopic myelitis: AM). MATERIAL AND METHODS: We carried out a nerve conduction study of the median, ulnar, tibial, and sural nerves in 21 patients with AM and in 28 patients with clinically definite or laboratory-supported definite multiple sclerosis (MS). RESULTS: The patients with AM showed a significantly higher frequency of abnormal records than the MS patients in the sensory nerve conduction study (52.4% vs. 14.3%, p = 0.0106). The frequency of abnormal records in the motor nerve conduction study in AM patients was twice as high as in MS patients (38.1% vs. 17.9%), but the difference was not statistically significant. Abnormality in the F-wave-evoked frequency in the median nerve was also significantly more common in AM patients than in MS patients (57.9% vs. 10.7%, p = 0.0016). CONCLUSIONS: These findings suggest that subclinical peripheral neuropathy is frequent in patients with AM.

Adult↗
PubMed2002

[A case of cerebellar ataxia showing severe dystonia masquerading as myoclonic jerky movements on arm extension].

A 43-year-old man was admitted to our hospital due to unstable walking, head tilting to the left and difficulty in extending his arm. He was quite healthy until the age of 20 years, when these symptoms appeared and progressed slowly afterward. Due to his unstable walking, he started to use a wheelchair when he was 39 years old. He had no family history of similar disease. On admission, neurological examination revealed spasmodic torticollis, ataxic speech and marked limb and truncal ataxia. Myoclonic jerky flexion of the forearm was induced when he raised and extended his forearm. He also showed mild hyperreflexia in the lower limbs without pathological reflexes. He had weakness and atrophy of the left supraspinatus, infraspinatus, deltoid and biceps brachii muscles and mild superficial sensory impairment in the left axillary nerve territory due to cervical spondylotic radiculopathy of the left C5 root. MRI of the brain demonstrated severe bilateral atrophy of the cerebellar hemispheres and vermis but minimal atrophy of the cerebrum and brainstem. Because surface electromyography revealed continuous discharge with phasic components in the biceps and wrist flexor muscles on extending the upper limbs, the jerky flexion movement of the forearm was considered to be primarily dystonia. Although no giant SEP was observed, a C-response was detected in the long-loop reflex in response to right median nerve stimulation. Nuclear examinations showed diffuse hypoperfusion and decreased glucose metabolism in the cerebellum. Based on these findings, we hypothesized that cerebellar dysfunction may have induced severe dystonic movement resembling myoclonus. We would like to name this complicated involuntary movement an "arm thrust". This is the first case to be reported of sporadic, chronic, progressive cerebellar ataxia accompanied by severe dystonic movement, especially on stretching the forearms, that mimics myoclonic movement.

Adult↗
PubMed2002

[A patient with Parkinson's disease complicated by hypothyroidism who developed malignant syndrome after discontinuation of etizolam].

A 59-year-old man, who was diagnosed as having Parkinson's disease and depression seven years ago and was on oral antiparkinsonian agents, antianxiety agents, and antidepressants, developed a high fever, disturbed consciousness, and marked muscle rigidity after discontinuation of etizolam and amitriptyline. He was admitted to a nearby hospital. Hypothyroidism had been noted two months before admission. Marked muscle rigidity and increased serum CK were observed. Since discontinuation of benzodiazepine has been known to rarely trigger a neuroleptic malignant syndrome (NMS), he was diagnosed as having NMS. After receiving dantrolene and bromocriptine, these symptoms temporarily improved but he again developed consciousness disturbance, and convulsive seizures associated with an elevated serum CK. He was transferred to our hospital. On admission, the CK level was normal at 168 IU/l, while free T4 was 0.6 ng/dl (normal range, 0.9-2.3) and TSH was 108.7 mU/ml (normal range, 0.2-4.2) in serum, indicating the presence of primary hypothyroidism. As an increase in thyroid hormone dosage improved the thyroid function to normal level, his disturbed consciousness and muscle rigidity gradually improved. Convulsive seizure and recurrence of NMS in a short interval are unusual in neuroleptic malignant syndrome. In this patient, hypothyroidism may have contributed to the development of malignant syndrome through metabolic changes of the central dopaminergic system, and discontinuation of etizolam, a kind of benzodiazepine, may have triggered NMS, since there has not been reported that discontinuation of antidepressants including amitriptyline triggers NMS.

Antidepressive Agents↗
PubMed2002

[A case of Charcot-Marie-Tooth disease (CMT) type 1 complicated by diabetes mellitus (DM) showing bilateral phrenic nerve palsy].

We here report a 44-year-old woman with Charcot-Marie-Tooth disease (CMT) type 1 who showed severe bilateral phrenic nerve palsy (PNP). She had chronic progressive distal dominant muscle weakness and atrophy since early in her second decade and had been unable to walk by herself due to weakness of the legs since she was 40-years old. At that time, she was diagnosed with diabetes mellitus (DM). She also had difficulty breathing when she was in a supine position. On admission, sural nerve biopsy showed a marked decrease of large and small myelinated fibers and numerous onion bulb formations, which are compatible with CMT type 1. Chest X-ray showed bilateral elevation of the diaphragm, which was more marked on the right side, indicating bilateral PNP. Since it is reported that CMT patients show demyelination of the phrenic nerve subclinically, and DM itself may facilitate the development of PNP, periodic evaluations of respiratory function may thus be useful for preventing respiratory failure in patients with CMT, especially when it is complicated with DM.

Adult↗
PubMedDate not supplied

[A patient with mitochondrial encephalomyopathy presenting gynecomastia with elevation of serum estriol level].

We report a 23-year-old man with mitochondrial encephalomyopathy. At 21 years of age, he noted speech distubance. Since his dysarthria did not improve thereafter, he was admitted to our hospital. On admission, he showed mild gynecomastia. Neurological examination revealed mild decrease in performance IQ in WAIS-R, mild scanning speech, mild left hearing disturbance, mild to moderate muscle weakness in proximal four extremities, mild bilateral limb ataxia, and mild to moderate truncal ataxia. While, no brisk deep tendon reflex, pathological reflex, aberrant muscle tonus, sensory disturbance, retinopathy, myoclonus or autonomic disorder was found. Serum levels of lactate (23.2 mg/dl, normal<18.7) and pyruvate (1.23 mg/dl, normal<0.94) were elevated, and serum lactate levels were markedly elevated (118.1 mg/dl) after 15-minute exercise (15 Watts/minute). CSF levels of lactate (31.2 mg/dl, normal<12.5) and pyruvate (1.48 mg/dl, normal<0.75) were also elevated. Head MRI showed mild cerebral and cerebellar atrophy, but 1H-MRS showed no lactate peak. Moreover, muscle biopsy from left biceps muscle showed lots of ragged-red fibers, and he was thus diagnosed as having mitochondrial encephalomyopathy. However, nt3243 mutation of mitochondria DNA was not present. Next, we confirmed gynecomastia by mammography, and checked serum levels of estrogens. Mildly decreased estradiol (19.9 pg/ml, normal, 20-59), normal estrone (24.0 pg/ml, normal<30.0) and mildly increased estriol (6.03 pg/ml, normal<5.0) were found. While, the serum levels of cortisol, dehydroepiandrosterone-sulfate (DHEA-S), androstenedione, testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were all within normal limits. Since the steroid hormone synthesis system and hypothalamus-pituitary system seem to be normal, 16alpha-hydroxylase that converts estradiol to estriol may be upregulated. While, aromatase (P-450arom) is well known to convert androgens to estrogens. In addition, 16alpha-hydroxylase and P-450arom convert DHEA-S to estriol. Since it is recently reported that P-450arom is considerably expressed in muscle tissues as well as fat tissues and that muscle tissue may be a major organ to produce estrogens in men and postmenopausal women, estriol production may be increased in the present patient's muscle. Although hypogonadism due to hypothalamus-pituitary disorders was sometimes reported, there have been no reports that suggest an increased estrogen production in skeletal muscles in mitochondrial encephalomyopathies. Recently, estrogen has been known to protect muscle fibers from oxidative damages due to exercise. Thus, it is of potential that estrogens increased locally in muscle tissues of the patients with mitochondrial encephalomyopathies protect muscle fibers from oxidative damage due to mitochondrial dysfunction.

Adult↗