Search PubMed⌕ Search

Biomedical subjects

M Suehara

Publications and source records attributed to M Suehara.

At least 37 records · Page 2Linked to original sources
PubMed1997

A new type of hereditary motor and sensory neuropathy linked to chromosome 3.

We report the clinical, pathological, and genetic findings of 23 patients in 8 families with hereditary motor and sensory neuropathy (proximal dominant form) (HMSN-P) in Okinawa, Japan. The clinical features were unique with respect to autosomal dominant inheritance, Kennedy-Alter-Sung syndrome-like proximal dominant neurogenic atrophy, obvious sensory involvement, painful muscle cramp, fasciculations, areflexia, and high incidences of elevated creatine kinase levels, hyperlipidemia, and diabetes mellitus. Electrophysiological and pathological studies revealed typical motor and sensory axonal neuropathy, and decreased numbers of anterior born and dorsal ganglion cells, which suggested the presence of neuronopathy in HMSN-P. Genetic linkage studies showed a lod score of 4.04 (two-point analysis) in DNA marker D3S1284. Haplotype analysis showed that the gene locus of the disease was mapped to 3p14.1-q13 bracketed by D3S1285 and D3S1281. In this region, the patients' chromosomes showed an obvious increase in the allele frequency of five markers. One allele in D3S1591 was identical in all patients but had a low frequency in the control population. This finding suggested the presence of linkage disequilibrium and a common origin of this allele in all patients with HMSN-P. The HMSN-P described here is a new clinical entity characterized by unique clinical manifestations and a new gene locus.

Adult↗
PubMed1997

[A case of tabes dorsalis observed in an HTLV-1 carrier].

We report a case of a 53-year-old female HTLV-1 carrier with tabes dorsalis. In addition to typical symptoms of tabes dorsalis, she presented HTLV-1 associated myelopathy (HAM) like clinical features such as sensory disturbance with thoracic sensory levels and bladder disturbance (pollakiuria). Although penicillin treatment did not improve in her neurological symptoms, steroid therapy was effective especially in HAM like symptoms. The CSF neopterin level was markedly decreased after steroid therapy, indicating that inflammation in the spinal cord was settled down after treatment. Our case suggests that CNS infection like tabes dorsalis may be modified by HTLV-1 infection and then present some atypical clinical features based upon altered immunological aspects of HTLV-1 carriers.

Carrier State↗
PubMed1996

Serum of Isaacs' syndrome suppresses potassium channels in PC-12 cell lines.

Blockage of K+ channels in nerve terminals by immunoglobulin is the speculated pathomechanism of Isaacs' syndrome. Using patch-clamp technique (whole-cell clamp), we investigated the effects on K+ current of serum taken from 2 patients with Isaacs' syndrome employing the clonal cell line PC-12. The addition of a patient's serum to the perfusion solution had little effect on the K+ current of P-12 cells. In contrast, K+ current was reduced by 25-80% when cells were cultured for 3-6 days with 2% serum as compared to control serum values. Suppression of the K+ current appears to develop gradually over the period of culture. Our results suggest that the pathomechanism of Isaacs' syndrome is caused by K+ channel suppression via a humoral factor(s) in the serum, which subsequently induces nerve hyperexcitability.

Adult↗
PubMed1995

Cardiac involvement in mitochondrial diseases. A study on 17 patients with documented mitochondrial DNA defects.

BACKGROUND: Mutations of mitochondrial DNA have been demonstrated as causes of human mitochondrial diseases. While these disorders typically involve multiple organs, the effect of mitochondrial mutations on the heart has not been systematically studied. METHODS AND RESULTS: We studied mitochondrial mutations and cardiac changes in 17 patients with Kearns-Sayre syndrome; ocular myopathy; myoclonus epilepsy with ragged red fibers (MERRF); and mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Cardiac involvement was evaluated by chest radiograph, ECG, His-bundle electrogram, and echocardiogram. All 3 patients with Kearns-Sayre syndrome had large deletions of mitochondrial DNA and disturbances in cardiac conduction. ECG abnormalities were found in 2 of 6 patients with ocular myopathy who showed large deletions of mitochondrial DNA. All 3 patients with MERRF had an A-to-G mutation at nucleotide position 8344; 2 had cardiomegaly, asymmetrical septal hypertrophy, and diffuse hypokinesis of the left ventricle. One patient with asymmetrical septal hypertrophy developed dilated cardiomyopathy 2 years later. All 5 patients with MELAS had an A-to-G mutation at nucleotide position 3243, and 2 had symmetrical left ventricular hypertrophy with or without abnormal wall motion. CONCLUSIONS: The clinical features of cardiac involvement in mitochondrial diseases vary in the different subgroups of these disorders. Particular mitochondrial mutations can cause characteristic cardiac abnormalities.

Adult↗
PubMed1995

Immunological abnormality in patients with lysinuric protein intolerance.

Lysinuric protein intolerance (LPI) is a rare hereditary disorder manifesting hyperammonemia induced by low levels of basic amino acids, these low levels being due to the impaired transport of these acids in the intestinal mucosa and the renal tubules. Low serum arginine levels and probably the consequently low in vivo levels of nitric oxide (NO), which against acts as a physiological and immunological mediator/modulator, are thought to influence the immunological status in patients with LPI. Accordingly, this study was conducted to. We found that patients with LPI had leukocytopenia, high serum IgG levels, a high ratio of CD44B4-positive lymphocytes (helper inducer) to CD42H4-positive lymphocytes (suppressor inducer), low levels of leukocyte phagocytic, cytotoxic, and natural killer cell activity, and increased spontaneous proliferation of lymphocytes. These results were probably the consequence of persistent low NO levels in vivo.

Adult↗
PubMed1993

Limited sequence divergence of HTLV-I of Indian HAM/TSP patients from a prototype Japanese isolate.

Nucleotide sequences of two HTLV-I proviruses isolated from Indian patients with HAM/TSP were analyzed. The sequence data of the env, pX, and LTR regions showed 98-99% homologies with the prototype HTLV-I, ATK-1, isolated from a Japanese ATL patient, indicating that HTLV-I isolates in India and Japan are similar, with minor variations. However, certain small sequences of noncoding regions in the pX and LTR showed differences of 6.1 and 7.2%, respectively, thus the conclusion could vary depending on the regions and length of the sequences used for comparison.

Adult↗
PubMed1993

[Juvenile Binswanger-type encephalopathy with alopecia and spondylosis deformans--a case report].

The patient is a 33-year-old male and his parents are first cousins. He noticed his hair loss since about the age 14. At age 29, he manifested gait disturbance and urinary incontinence, which gradually progressed. Neurologically, he showed dementia (WAIS < 64), pyramidal and extrapyramidal signs, and pseudobulbar palsy. His blood pressure was normal. He also had dry skin with sclerema and marked cervical and lumbar spondylosis. His brain CT showed enlargement of the lateral ventricles and the periventricular low density areas. T2 weighted image of MRI showed diffuse high intensity in the periventricular white matter. Yamada et al presented a case progressive subcortical vascular encephalopathy (Binswanger type) with alopecia and spondylosis as a possible new syndrome, and this patient has the same syndrome. The etiology of this syndrome has not been known at the present time. The biopsied skin from the patient showed much hyaline deposits like glycoprotein in perivascular area of dermis. These morphological changes are very similar to those of lipoid proteinosis. These findings suggested that the pathological mechanism of this syndrome might be related to the biochemical disturbance in lipoid proteinosis.

Adult↗
PubMed1992

Pathological changes in skeletal muscle in HTLV-I-associated myelopathy.

The main lesion site of HTLV-I-associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the pyramidal tract. In some HAM patients, clinical symptoms and findings indicate neuromuscular involvement, such as muscular atrophy, fasciculation, elevated serum creatine kinase (CK) or significant electrophysiological data. Cases of HAM/TSP complicated with polymyositis or motor neuron disease have been reported. But no investigation has been directed to muscular pathology in many patients of HAM/TSP. We conducted muscle biopsies on 13 HAM patients. Four patients showed neurogenic changes. Six patients showed histological findings indicative of inflammatory myopathy. We investigated surface marker of invading cells in these 6 patients. In all patients, T lymphocytes were more predominant than B lymphocytes and in three of them T helper/inducer cells were more predominant than T suppressor cells. In 2 patients, only slight myopathic change could be seen, such as variation in fiber diameter and increase in the number of internal nuclei. In 1 patient, type 2 fiber atrophy was seen, and was possibly the result of disuse. Disturbance of secondary motor neurons or inflammatory myopathy is thus shown to be possibly associated with HAM/TSP.

Adult↗
PubMed1992

[Significance of anti-HTLV-I antibody in cerebrospinal fluid in diagnosis of HTLV-I associated myelopathy (HAM)].

Anti-HTLV-I antibody was measured in 69 cerebrospinal fluids (CSFs) of cases with typical HTLV-I associated myelopathy (HAM) and other disorders whose symptoms were similar to HAM in order to evaluate the diagnostic significance of anti-HTLV-I antibody in CSF. Both gelatin particle agglutination (PA; Serodia-ATLA) method and recombinant gag-env hybrid protein coated ELISA were employed simultaneously. Antibody titers of both methods showed linear correlation. Cases with typical HAM (24 cases) and HAM with additional neurological manifestations (7 cases) showed high positivity in both methods. Cases with other neurological disorders with possible HAM (11 cases, seropositive) and cases with other neurological disorders without HAM (12 cases, seropositive) showed low positivity with low titer in ELISA, on the other hand, 81% and 67% of those cases were positive in PA method. All cases with seronegative neuroimmunological disorders (15 cases) were negative in CSFs. These findings showed that anti-HTLV-I antibody in CSF is significant in diagnosis of HAM, and both PA and gag-env ELISA are useful to detect anti-HTLV-I antibodies in CSF.

Agglutination Tests↗
PubMed1991

Epidemiology of progressive muscular dystrophy in Okinawa, Japan. Classification with molecular biological techniques.

We studied the prevalence of various types of progressive muscular dystrophy (PMD) in Okinawa, Japan on December 31, 1989 and the incidence of Duchenne muscular dystrophy (DMD) in 5-year periods from 1957 to 1985. We classified patients with PMD clinically, electrophysiologically, molecular biologically and immunohistochemically with antidystrophin antibody, especially for sporadic cases of DMD, Becker muscular dystrophy (BMD) and limb-girdle muscular dystrophy (LG). The prevalence for all PMD in Okinawa was 7.13 X 10(-5) for DMD, 1.82 X 10(-5) for BMD in the male population, 1.55 X 10(-5) for LG, 1.14 X 10(-5) for congenital muscular dystrophy, 2.03 X 10(-5) for facioscapulohumeral muscular dystrophy (FSH), and 9.13 X 10(-5) for myotonic dystrophy (MD) in the total population. The incidence of DMD in the period 1957-1985 was 15.41 X 10(-5) live-born males (LBM) and 3.21 X 10(-5) LBM for BMD. The incidence has apparently declined in Okinawa since 1975. The prevalence of BMD, FSH and MD was rather high in Okinawa compared with previous reports. Molecular biological techniques for classifying patients were indispensable for the epidemiological study of PMD.

Cross-Cultural Comparison↗
PubMed1991

[A case of rigid spine syndrome associated with severe respiratory failure].

Rigid spine syndrome (RSS) is clinically characterized by progressive limitation of flexion of the spine and contractures of other joints. We herein report a 27-year-old man with RSS, who underwent tracheotomy because of severe restrictive respiratory failure. He had limitation of neck flexion and proximal muscle weakness from early childhood and was diagnosed as having muscular dystrophy at 16 years old. He was suffered from dyspnea and his first tracheotomy was performed at 24 years old. Two years later, the second tracheotomy was done because his respiratory failure was aggravated. He had limitation of spine flexion, scoliosis, but no limited range of elbow and wrist joints movement except mild contracture of ankle joints. Serum CK level was elevated to 590 IU/L. Repeated ECG examinations showed negative T wave but no conduction block. In his family, his parents and brother had neither similar clinical symptoms nor heart block. Chest X-ray study showed elevated diaphragm and enlarged heart shadow (CTR = 65%). Percent VC and FEV1 in sitting position were 14.6% and 100%, respectively. Arterial blood gas analysis showed PaO2 of 34.2 mmHg and PaCO2 of 77.2 mmHg. The density of paraspinal muscle in CT scan was severely decreased. Needle EMG showed myogenic change. Muscle biopsy from left biceps brachii showed myopathic change with mild type 2 fiber grouping. After the second tracheotomy, he was on a respiratory during sleep but mostly off in the daytime. His clinical features are different from Emery-Dreifuss muscular dystrophy because he had no heart conduction block and no family history, but progressive respiratory failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Association of a particular amino acid sequence of the HLA-DR beta 1 chain with HTLV-I-associated myelopathy.

Analyses of HLA-DRB1 gene using polymerase chain reaction and sequence-specific oligonucleotide probes reveal that the amino acid sequence Glu-Gln-Arg-Arg-Ala-Ala-Val at positions 69-75 of the third hypervariable region (HVR) of HLA-DR beta 1 chain is significantly associated with HTLV-I-associated myelopathy (HAM). Since the frequency of this sequence in HTLV-I carriers is almost the same as that in controls from Kagoshima (an endemic area of HTLV-I), this sequence may be related to susceptibility to HAM rather than to susceptibility to HTLV-I infection. Since this third HVR functions as putative antigen-binding sites and T cell recognition sites, the amino acid sequence of positions 68-73 was analyzed in detail. The analysis reveals that Gln70 and Arg71 are relevant to the occurrence of HAM.

Alleles↗
PubMed1989

Electroencephalographic abnormalities in human T-cell lymphotropic virus type I-associated myelopathy.

Thirty-six patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy were studied by electroencephalogram. Twenty-two of 36 patients showed mild to moderate electroencephalographic abnormalities, ranging from poor organization or slowing of the background activity to theta bursts and/or spikes. None of these abnormalities were considered specific for HTLV-I-associated myelopathy. These electroencephalographic abnormalities had no apparent relationship to duration or severity of illness, nor to HTLV-I antibody titers in the cerebrospinal fluid. We document electroencephalographic changes in HTLV-I-associated myelopathy. Our data are consistent with previous reports describing the fact that involvement of regions above the spinal cord may exist in HTLV-I-associated myelopathy.

Adult↗
PubMed1989

Germanium myopathy: clinical and experimental pathological studies.

Pathological examinations were carried out on the skeletal muscle of a patient with germanium intoxication. The prominent histochemical finding was vacuolar myopathy with lipid excess, increased acid phosphatase activity and decreased cytochrome c oxidase activity. Ultrastructural lesions revealed a mitochondrial abnormality, autophagic vacuoles and accumulation of high electron-dense materials in deformed mitochondria and at the periphery of lipid droplets. Furthermore, the toxic effect of germanium on skeletal muscle was confirmed by the experimentally induced germanium myopathy, which showed autophagic degeneration, decreased cytochrome c oxidase activity and a mitochondrial abnormality with high electron-dense materials.

Child, Preschool↗