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Biomedical subjects

K Sahashi

Publications and source records attributed to K Sahashi.

At least 19 recordsLinked to original sources
PubMed2004

Progressive myopathy with circulating autoantibody against giantin in the Golgi apparatus.

A woman aged 59 years with adult-onset progressive myopathy had anti-Golgi (giantin) autoantibody in the serum. Limb-muscle biopsy revealed chronic myopathy with paucity of cellular reactions and reduced immunostaining for alpha-dystroglycan. The similarity of the current patient with cases of hereditary alpha-dystroglycanopathies (Fukuyama-type congenital muscular dystrophy, Walker-Warburg syndrome, muscle-eye-brain disease, congenital muscular dystrophy type 1C, and limb-girdle muscular dystrophy type 2I) suggests that the Golgi apparatus is the target organelle in a subset of myopathies.

Antibody Specificity↗
PubMed2003

Dysferlin mutations in Japanese Miyoshi myopathy: relationship to phenotype.

OBJECTIVE: To study dysferlin gene mutations and genotype-phenotype correlations in Japanese patients with Miyoshi myopathy (MM). BACKGROUND: MM is an autosomal recessive distal muscular dystrophy that arises from mutations in the dysferlin gene. This gene is also mutated in families with limb girdle muscular dystrophy 2B. METHODS: The authors examined 25 Japanese patients with MM. Genomic DNA was extracted from the peripheral lymphocytes of the patients. The PCR products of each of 55 exons were screened by single strand conformation polymorphism or direct sequencing from the PCR fragments. RESULTS: The authors identified 16 different mutations in 20 patients with MM; 10 were novel. Mutations in Japanese patients are distributed along the entire length of the gene. CONCLUSIONS: Four mutations (C1939G, G3370T, 3746delG, and 4870delT) are relatively more prevalent in this population, accounting for 60% of the mutations in this study. This study revealed that the G3370T mutation was associated with milder forms of MM and the G3510A mutation was associated with a more severe form.

Adult↗
PubMed2003

Anti-Ma2 antibody related paraneoplastic limbic/brain stem encephalitis associated with breast cancer expressing Ma1, Ma2, and Ma3 mRNAs.

A 69 year old woman presented with cognitive impairment and supranuclear gaze palsy caused by paraneoplastic limbic/brain stem encephalitis associated with atypical medullary breast carcinoma. The cerebrospinal fluid from the patient harboured an anti-neuronal cell antibody against Ma2 antigen, but not against Ma1 or Ma3 antigen. Despite the antibody being restricted to the Ma2 antigen, the patient's cancer tissue expressed Ma1, Ma2, and Ma3 mRNAs. These results, and the expression of Ma2 mRNA in an atypical medullar breast carcinoma in another patient without paraneoplastic encephalitis, indicate that the induction of anti-Ma2 antibody depends on host immunoreponsiveness and not on the presence of the antigen itself in the cancer.

Aged↗
PubMed2000

[A case of myasthenia gravis following sarcoidosis and Hashimoto's thyroiditis].

Here, we report on an elderly woman with sarcoidosis and Hashimoto's disease who later developed myasthenia gravis. She was 68-year-old with a long history of Hashimoto's disease who had a clinical diagnosis of sarcoidosis with uveritis at the age of 66 years. On laboratory examination, angiotensin-converting enzyme, lysozyme and gamma-globulin were elevated and there was bilateral hilar lymphoadenopathy. She was admitted to our hospital because of left blepharoptosis and mild fatigability in the proximal muscles at the age of 68 years. Myasthenia gravis, type IIa, was confirmed by elevated titer of anti-acetylcholine receptor antibody in serum (0.8 nmol/l, normal < 0.6), positive edrophonium test and decremental EMG response. Oral prednisolone therapy was effective. Her muscle biopsy revealed HLA ABC-positive fibers in all fascicles, and HLA-DR positive fibers in the perifascicular areas. Myasthenia gravis complicated by sarcoidosis and Hashimoto's thyroiditis is extremely rare, suggesting that the common underlying immunological abnormalities for the three disorders such as a certain defective cellular immunity are responsible for the pathomechanism to induce the patient condition.

Aged↗
PubMed2000

[A case of LGMD2A identified with both western blot analysis and immunostaining of calpain 3 in biopsied muscle].

A 45-year-old housewife had proximal dominant limb muscle weakness from around 25 years of age. Her parents were cousins. None of family members was affected. Progressive muscle weakness and atrophy were prominent at the posterior compartments of legs and trunk. Serum CK was moderately elevated. Muscle pathology revealed variation in fiber size, moderate increase in numbers of internal nuclei and abundant lobulated fibers. On immunostaining using by monoclonal antibody against human calpain 3 (NCL-CALP-2 C4; Novocastra) to the biopsied muscle, calpain 3 was completely absent in the sarcoplasm, while granular debris and in part positive striation were noted in control muscle. By Western blot analysis, a band corresponding to 94 kDa of calpain 3 was not detected. A genetic analysis of calpain 3 revealed homozygous C-565-G mutation (Leu189Val). From the present study. Western blot analysis and immunostaining by using calpain 3 antibody were suggested to be useful to diagnose LGMD2A in LGMD patients.

Biomarkers↗
PubMed1998

(R)salsolinol N-methyltransferase activity increases in parkinsonian lymphocytes.

Recently, an endogenous catechol isoquinoline, 1(R),2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [N-methyl(R)salsolinol], was proved to be a neurotoxin specific for dopamine neurons by in vivo and in vitro experiments. This N-methyl(R)salsolinol was found to increase significantly in the cerebrospinal fluid of untreated parkinsonian patients, suggesting its possible involvement in the pathogenesis of Parkinson's disease. To clarify the mechanism of the increase, the activity of enzymes related to the metabolism of the neurotoxin was examined in lymphocytes prepared from parkinsonian patients and controls. In patients with Parkinson's disease, the activity of a neutral N-methyltransferase, measured by using (R)salsolinol as a substrate, was found to increase significantly (100.2 +/- 81.8 pmol/min/mg of protein) in comparison with that in controls (18.9 +/- 15.0 pmol/min/mg of protein). The distribution of the activity was bimodal in the parkinsonian patients, whereas it was singular in controls. The activity of other related enzymes, an alkaline N-methyltransferase and N-methyl(R)salsolinol oxidase, in parkinsonian lymphocytes was the same as in controls. Increase of the neutral N-methyltransferase may be an endogenous factor in the pathogenesis of Parkinson's disease.

Aged↗
PubMed1998

Renin-producing adrenal tumor: report of a case.

A 19-year-old man with an adrenal tumor associated with hypertension is herein described. The plasma renin activity (PRA) was markedly elevated and the plasma aldosterone level was also increased. The catecholamine level was within the normal range and the glucagone-regitine test was negative. An angiogram revealed the left renal artery to have no stenotic segments, but instead was curved caudally. Magnetic resonance imaging showed a tumor measuring about 8 cm in diameter to be clearly recognized from the left kidney. The blood pressure did not drop when a calcium-channel blocker was used, but was gradually stabilized with the angiotensin converting enzyme (ACE) antagonist. The adrenal tumor was then removed surgically. Normal adrenal tissue was scarcely recognized to the left of the tumor. After surgery, the PRA decreased and blood pressure stabilized rapidly without the ACE antagonist. The possibility of massive renal renin secretion due to suppression by the adrenal tumor was excluded by a method using an antibody to purified human renin.

Adrenal Gland Neoplasms↗
PubMed1997

Spinocerebellar ataxia type 6: CAG repeat expansion in alpha1A voltage-dependent calcium channel gene and clinical variations in Japanese population.

Autosomal dominant spinocerebellar ataxias (SCAs) are clinically and genetically a heterogeneous group of neurodegenerative disorders. Recently, mild CAG repeat expansion in the alpha1A voltage-dependent calcium channel gene has been found to be associated with a type of autosomal dominant SCA (SCA6). We analyzed 98 Japanese families with autosomal dominant SCAs, for whom CAG repeat expansions of the SCA1, SCA2, Machado-Joseph disease/SCA3, and dentatorubral-pallidoluysian atrophy genes were excluded, and 5 apparently sporadic cases of cortical cerebellar atrophy. The diagnosis of SCA6 was confirmed in 30 families (31%) comprising 47 affected individuals and 1 sporadic case. The size of expanded CAG repeats ranged from 21 to 26 repeat units and was found to be correlated inversely with age at onset. We identified 2 SCA6 patients homozygous for expanded CAG repeats, whose ages at onset were earlier than the 95% lower confidence level, suggesting the presence of a gene dosage effect of expanded CAG repeat. Ataxia is the most common initial symptom found in 45 of the 48 patients. Patients with a prolonged disease course showed other accompanying clinical features including dystonic postures, involuntary movements, and abnormalities in tendon reflexes.

Adult↗
PubMed1997

[Clinico-pathological significance of the immunostaining of myosin heavy chain isoforms in pathological human skeletal muscle].

Expression of the four myosin heavy chain isoforms (fast-twitch, slow-twitch, neonatal and embryonal isoforms) was immunohistochemically observed in 500 biopsied limb muscles of neuromuscular disorders. Fast-twitch isoform was expressed in type 2A, 2B and pathologic 2C fibers. Slow-twitch isoform was expressed in type 1 and 2C fibers. Embryonic isoform was expressed in regenerating type 2C fibers of active myopathies such as Duchenne dystrophy and polymyositis. Expression of neonatal isoform, which was longer positive than that of embryonic isoform, was noted in regenerating fibers, denervated fibers and highly atrophic fibers in chronic myopathies of limb-girdle dystrophy and myotonic dystrophy. In conclusion, the immunostaining of MHC isoforms are useful to make a clinico-pathological diagnosis to determine the stages in evolution of regeneration or degeneration of pathologic muscle fiber per se.

Humans↗