Search PubMed⌕ Search

Biomedical subjects

K Arahata

Publications and source records attributed to K Arahata.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Cardiomyopathy in Becker muscular dystrophy].

In 6 patients with dystrophin-verified Becker muscular dystrophy (BMD), 3 patients had dilated cardiomyopathy (DCM group). The other 3 patients (non-DCM group) also had ECG abnormalities including incomplete right bundle branch block, left ventricular enlargement and intraventricular conduction defect. Between DCM and non-DCM group, there was no prominent difference in ages at onset, mean duration and severity of muscular weakness. Serum CK levels, and molecular weight and amount of dystrophin also showed no significant difference between two groups. On reviewing 14 BMD patients, including 3 present patients with cardiomyopathy, the cardiac symptoms appeared from 4 to 41 years, averaging 17.1 years of age. The mean duration of muscle symptoms was 9 years, ranging from 0 to 33 years. There was no correlation between severity of muscle weakness and cardiomyopathy. Six patients died of heart failure and 3 received cardiac transplantation. Thus there was no characteristic clinical feature in BMD patients with cardiomyopathy except for very poor prognosis. Since the myocardial involvement is not related with clinical severity and duration of the disease, careful observation for cardiac function should be carried out in all BMD patients even in the early stage of muscle weakness.

Adolescent↗
PubMed1990

[Muscle regeneration in mdx mouse, and a trial of normal myoblast transfer into regenerating dystrophic muscle].

The most ideal therapeutic trial on Duchenne muscular dystrophy (DMD) is a transfer of normal myoblasts into dystrophic muscle which has been attempted on animal models in several institutes. In the process of muscle regeneration, the transferred normal myoblasts are expected to incorporate into the regenerating fibers in host dystrophic mouse. To know the capacity of muscle regeneration in dystrophic muscle, we compared the regenerating process of the normal muscle with that of the dystrophic muscle after myonecrosis induced by 0.25% bupivacaine hydrochloride (BPVC) chronologically. In the present study, C57BL/10ScSn-mdx (mdx) mouse was used as an animal model of DMD and C57BL/10ScSn (B10) mouse as a control. There was no definite difference in the behavior of muscle fiber regeneration between normal and dystrophic muscles. The dystrophic muscle regenerated rapidly at the similar tempo to the normal as to their size and fiber type differentiation. The variation in fiber size diameter of dystrophic muscle, however, was more obvious than that of normal. To promote successful myoblast transfer from B10 mouse into dystrophic mdx mouse at higher ratio, cultured normal myoblasts were transferred into the regenerating dystrophic muscle on the first and the second day after myonecrosis induced by BPVC. Two weeks after the myoblast injection, the muscles were examined with immunohistochemical stain using anti dystrophin antibody. Although dystrophin-positive fibers appeared in dystrophic muscle, the positive fibers were unexpectedly small in number (3.86 +/- 1.50%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Mosaic expression of dystrophin in symptomatic carriers of Duchenne's muscular dystrophy.

A deficiency of the protein dystrophin is known to be the cause of Duchenne's muscular dystrophy. To examine the expression of dystrophin in symptomatic female carriers of this X-linked recessive disorder, we performed immunohistochemical studies on muscle-biopsy specimens from three such carriers, using an antiserum raised against a synthetic peptide fragment of dystrophin. In all three carriers, most individual muscle fibers reacted either strongly or not at all to the antiserum for dystrophin; only 2 to 8 percent of fibers showed partial immunostaining. This mosaic staining pattern was present on both cross-sectional and longitudinal muscle specimens. Although the mosaic pattern was seen in all fiber types, more than 80 percent of type 2B and 2C fibers from two of the carriers did not react with the antiserum. Similar studies in nine normal subjects showed consistently strong staining of all muscle fibers. No muscle fibers from 31 patients with Duchenne's muscular dystrophy reacted with the antiserum. We conclude that symptomatic carriers of Duchenne's muscular dystrophy can be identified by a distinct mosaic pattern in the immunohistochemical staining of the surface membrane of skeletal-muscle specimens. This finding may have practical implications for genetic counseling, although it remains to be shown whether the same staining pattern will be found in muscle specimens from asymptomatic carriers of Duchenne's muscular dystrophy.

Adolescent↗
PubMed1989

Progression in nemaline myopathy.

Four of seven patients with nemaline myopathy had severe, rapidly progressing symptoms. These four showed an increase in acid phosphatase activity in muscle fibers demonstrated by histochemistry and cathepsin B&L activity by biochemical measurement. On electron microscopy, nemaline bodies, occasionally disorganized myofibrils and autophagic vacuoles containing sarcoplasmic debris and glycogen particles were seen. Focal myofibrillar degeneration, through an unknown pathogenetic mechanism, induces an increase in lysosomal enzymes in the skeletal muscles which may be closely correlated with a rapid aggravation of muscle weakness in nemaline myopathy.

Acid Phosphatase↗
PubMed1989

Major histocompatibility complex class I antigen expression, immunolocalization of interferon subtypes, and T cell-mediated cytotoxicity in myopathies.

Major histocompatibility complex class I (MHC-I) expression on target cells is a prerequisite for antigen-specific T cell-mediated cytotoxicity (TCMC). Enhanced MHC-I expression has been attributed to interferons (IFNs) released from inflammatory cells. In previous studies, we found evidence of TCMC (invasion of non-necrotic muscle fibers by cytotoxic T cells) in polymyositis (PM) and in inclusion body myositis (IBM). We occasionally found evidence of TCMC in Duchenne dystrophy (DD) but not in dermatomyositis (DM). This study examines the relationships between TCMC, MHC-I expression, and IFN immunoreactivity in these diseases and normal controls. In controls, reactivity for MHC-I was confined to blood vessels. In all diseases, regenerating fibers expressed MHC-I. In IBM, PM and DD, all nonnecrotic muscle fibers invaded by CD8+ cells and some adjacent fibers expressed MHC-I. In DM, myriad muscle fibers expressed MHC-I but none were invaded by CD8+ cells. In all diseases, only a few mononuclear cells and no muscle fiber surfaces were immunoreactive for IFNs. We conclude that MHC-I expression on muscle fibers is necessary but not sufficient for TCMC in myopathy; that the biological significance of increased MHC-I expression in DM remains undefined; and that currently available and appropriately controlled immunocytochemical methods show no relationship between increased MHC-I expression on muscle fibers and local IFN synthesis by mononuclear cells.

Alkaline Phosphatase↗
PubMed1989

Dystrophin diagnosis: comparison of dystrophin abnormalities by immunofluorescence and immunoblot analyses.

Immunoblot characterization and immunofluorescence localization of dystrophin are presented for 76 human patients with various neuromuscular diseases. Normal dystrophin (shown by immunoblotting) was invariably visualized as a continuous, peripheral membrane immunostaining of myofibers. Biochemical abnormalities of dystrophin (either lower or higher molecular weight dystrophin) resulted in patchy, discontinuous immunostaining, suggesting that the abnormal dystrophin proteins are not capable of creating a complete membrane cytoskeleton network. There was a very strong correlation of clinical diagnoses with the type of dystrophin abnormality; all Duchenne muscular dystrophy patient muscle contained no detectable dystrophin, Becker muscular dystrophy patient muscle had clearly abnormal dystrophin, and unrelated diseases showed normal dystrophin. However, a single patient of five carrying the diagnosis of Fukuyama dystrophy showed no detectable dystrophin and thus appeared to be a Duchenne dystrophy patient by the biochemical assays. We know of no other case of a patient with a disease thought to be unrelated to Duchenne/Becker dystrophy yet demonstrating dystrophin deficiency. Based on the data presented, we conclude that immunofluorescence is the best technique for the detection of female carriers of Duchenne dystrophy, whereas immunoblotting appears superior for the prognostic diagnosis of Becker muscular dystrophy.

Amino Acid Sequence↗
PubMed1989

[Genetic studies of Duchenne muscular dystrophy families using the dystrophy families using the dystrophin cDNA].

The cDNA probes for the Duchenne muscular dystrophy (DMD) gene can detect deletions in over 50% of affected males and provide a highly accurate diagnostic test in the affected families. We present the results of our recent molecular genetic studies of five DMD families (six affected males and 16 non-affected family members) by using the dystrophin cDNA. Five molecular deletions were identified in the DNA samples of six affected males by studying abnormalities of Hind III and Bgl II fragments detected by the entire dystrophin cDNA. We could not find any abnormality in a family by the same DNA analysis. Deletion was found at two different loci; in two of six probands, it was located near 5' region of the gene seen by cDNA segment 1-2 a, while in the other three, near the center of the gene covered by cDNA segment 8. In three females of the five families, we detected novel fragments, the size of which was altered due to molecular deletion. These results greatly facilitated diagnosis of the carrier status in females. We studied also the dystrophin location in the biopsied skeletal muscle (femoral muscle) in a family, by means of indirect immunofluorescence staining using antiserum against dystrophin. Dystrophin was positive in the surface membrane of muscles from a non-affected brother, mother and sister, but it was absent in the muscle from a DMD proband.

DNA Probes↗
PubMed1989

[A case of progressive myopathy with tubular aggregates].

Tubular aggregates (TA) are unusual intramuscular structures stained basophilic on hematoxilin and eosin (HE) staining and red on modified Gomori trichrome (GT) staining. The structures are said to be originated from sarcoplasmic reticulum and are collections of tubules with double membranes on electron microscopic studies. The TA are usually seen in biopsy muscles from patients with muscle pain and cramps but without muscle weakness, periodic paralysis or alcoholic myopathy. In addition, there are five reports on families with progressive myopathy and tubular aggregates in the literature. We presented here a 48-year-old postman without any family history, who had had progressive muscle weakness for 17 years. He had never noticed pain or cramps in his muscles, not taken any particular medicine, and not had regular alcoholic beverages. There was no ptosis, facial weakness, masticatory muscle weakness or dysphagia. Muscle wasting, started from the proximal part of four extremities had progressed to the distal part of them. He could not walk on heels or toes and walked with waddling gait. He stood up with Gowers' maneuver. Serum GOT, GPT and CK were elevated. EMG showed myogenic pattern and MCV was normal. The muscle biopsies were performed; the first one taken from quadriceps femoris muscle at 42 years old showed myopathic changes including marked variation in fiber sizes, with scattered necrotic fiber splitting and TA in type 2B fibers. The second biopsy from biceps brachii muscle at the age of 48 years, showed densely proliferated fibrous tissues, marked variation fiber sizes and scattered split fibers. The TA were rarely seen and type 2B fibers were decreased in number.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1989

[A case of polymyositis with repeated dysphagia and muscle weakness associated with peculiar findings of skin].

A case of polymyositis with repeated dysphagia and muscle weakness associated with peculiar findings of skin was reported. The patient was a 67-year-old man. His birth and development was normal. There was no family history of neuromuscular disease. On 26th March 1987 he was admitted to a hospital because of dysarthria and dysphagia after fever and diagnosed as having viral myositis. His conditions improved spontaneously with bed rest and he left hospital on 14th April. On 23rd April he had chill and sore throat with fever. On 27th he was admitted to the same hospital because of dysarthria and muscle weakness of the proximal portion of the upper limbs. These symptoms also improved with bed rest. He had repeated these symptoms several times and then he was admitted to our hospital on 12th June. On examination he showed the skin pigmentation under the right eye and the eruption in the back of hands and the buttocks. Muscle weakness was observed in the proximal portion of the upper limbs and the neck flexor. Laboratory tests in admission were as follows: sGOT 49 mU/ml, sGPT 104 mU/ml, LDH 1064 mU/ml, CPK 565 mM/ml, aldolase 25.2 IU/1/37 degrees C. Electromyography showed the typical myogenic changes and biopsy of left biceps brachii revealed inflammatory cells in the muscle fiber which are specific to polymyositis. Immuno-histochemical study is performed to analyse the subpopulation of mononuclear cells in biopsied muscle and skin. Mononuclear cells infiltrated into perimysium, endomysium and epidermis were positive for T11 and T8, but less positive for T4, B1 and Leu11. On the basis of these findings he was diagnosed as having "polymyositis syndrome".

Aged↗
PubMed1988

Immunostaining of skeletal and cardiac muscle surface membrane with antibody against Duchenne muscular dystrophy peptide.

Duchenne muscular dystrophy (DMD) is a debilitating X-linked muscle disease. We have used sequence information from complementary DNA clones, derived from the gene that is deleted in DMD patients, to generate an antiserum that stains the surface membrane of intact human and mouse skeletal muscle, but not that of DMD patients and mdx mice. Here we identify the protein reacting with this antiserum as a single component of relative molecular mass 210,000 (Mr = 210K) that fractionates with a low-ionic strength extract of intact human and mouse skeletal muscle. It is therefore distinct from the 400 K protein found in the heavy microsomal fraction of normal muscle and identified as a putative product of the DMD gene. We also analyse further the disease specificity of the antiserum. Positive staining is seen in normal controls, and in samples from patients with a wide range of muscular dystrophies other than DMD. Becker muscular dystrophy, which is allelically related to DMD, was the only other exception, and gave a sporadic staining pattern. The demonstration of a specific defect in the surface membrane of DMD muscle fibres substantiates the hypothesis that membrane lesions may initiate muscle degradation in DMD.

Animals↗
PubMed1988

Monoclonal antibody analysis of mononuclear cells in myopathies. IV: Cell-mediated cytotoxicity and muscle fiber necrosis.

Cell-mediated muscle fiber injury occurs in inclusion body myositis (IBM), polymyositis (PM), and even in Duchenne dystrophy (DD). Most of the autoaggressive cells are T cells and macrophages, but some are killer/natural killer (K/NK) cells. We here compare the frequencies per 1,000 muscle fibers of endomysial K/NK cells of varying cytotoxicity with those of T cells and macrophages in 8 cases each of IBM, PM, and DD. Two-micrometer serial cryostat sections were analyzed. The Leu-4 marker, present on all T cells and some K/NK cells, and the Leu-7 and Leu-11 markers, present on K/NK cells, were localized by paired immunofluorescence. Macrophages were demonstrated by the acid phosphatase reaction. In IBM, PM and DD, the respective average cell counts per 1,000 muscle fibers were: Leu-4+7- cells (T cells not expressing a K/NK marker)--710, 530, and 59; Leu-4+7+ cells (K/NK cells of low K/NK cytotoxicity)--294, 163, and 13; Leu-4-7+ cells (K/NK cells of intermediate cytotoxicity)--32, 10, and 2; and macrophages--292, 251, and 38. Leu-11+ K/NK cells that have the highest killing activity were virtually absent in all cases. The data suggest a limited role for antigen and major histocompatibility complex unrestricted K/NK cells, as compared with antigen-specific and major histocompatibility complex-restricted T cells, in IBM and PM. Further, the findings cast doubt on the significance of either T cells or K/NK cells in mature muscle in DD.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Monoclonal antibody analysis of mononuclear cells in myopathies. V: Identification and quantitation of T8+ cytotoxic and T8+ suppressor cells.

In polymyositis (PM) and inclusion body myositis (IBM), but not in dermatomyositis there is evidence of cell-mediated cytotoxicity: T8+ cells accompanied by macrophages focally surround, invade, and destroy nonnecrotic muscle fibers. However, the T8 marker appears on both cytotoxic (Tc) and suppressor (Ts) cells. The Leu-15 marker appears on Ts but not on Tc cells, but it also appears on macrophages and on some killer/natural killer cells. To obviate this problem, the T8, Leu-15, and Leu-7 markers were demonstrated by sequential paired immunofluorescence in single cryostat sections. Using this approach, we reliably differentiated for the first time between Tc and Ts cells in tissue sections. Six cell phenotypes were identified: T8+ Leu-15-Leu7- Tc cells, T8+ Leu-15+ Leu-7- Ts cells, three types of Leu-7+ killer/natural killer cells, and T8-Leu-15+ Leu-7- macrophages. Muscle specimens from 5 patients with PM and 5 with IBM were studied. In each case, 6 nonnecrotic muscle fibers focally surrounded and invaded by mononuclear cells were selected randomly. A total of 2,022 mononuclear cells were analyzed, 870 from patients with PM and 1,152 from those with IBM. When counts of the identified cell phenotypes in individual patients were pooled, there were four times as many T8+ Leu-15- Leu-7- Tc cells as T8+ Leu-15+ Leu-7- Ts cells in either PM or IBM samples. However, when the relative frequencies of the Tc and Ts cells were examined in individual patients, the Tc cells tended to become more abundant, and the Ts cells correspondingly less abundant, with the duration of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗