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Biomedical subjects

S Shoji

Publications and source records attributed to S Shoji.

At least 55 records · Page 3Linked to original sources
PubMed2000

A gene on SCA4 locus causes dominantly inherited pure cerebellar ataxia.

BACKGROUND: Several different genes or their loci have been identified for autosomal dominant cerebellar ataxia (ADCA). However, other types of ataxia remain unassigned. OBJECTIVE: To identify a new locus for ADCA. METHODS: Six Japanese families with ADCA with pure cerebellar syndrome (ADCA type III) were examined. These families had been molecularly excluded for spinocerebellar ataxia (SCA) types 1 through 3, 5 through 8, and 10. Clinical examination was undertaken, and a genome-wide linkage search was performed on 250 microsatellite DNA markers. RESULTS: Strong evidence for linkage was found with markers on human chromosome 16q, and haplotype and multipoint analyses further refined the gene locus in a 10.9-cM interval between D16S3089 and D16S515. Linkage disequilibrium was further found with the marker D16S3107 within the interval. The locus was exactly the candidate interval of SCA4, a rare form of ADCA clinically characterized by ataxia with sensory neuropathy and pyramidal tract signs. This would suggest that SCA4 and our ADCA type III are likely to be allelic disorders with different clinical features. CONCLUSION: The current study provides evidence that a gene on the SCA4 locus causes a pure cerebellar syndrome.

Aged↗
PubMed2000

Cell cycle arrest enhances the in vitro cellular toxicity of the truncated Machado-Joseph disease gene product with an expanded polyglutamine stretch.

Machado-Joseph disease (MJD) is an inherited neurodegenerative disorder caused by the expansion of the polyglutamine stretch in the MJD gene-encoded protein, ataxin-3. Using a series of deletion constructs expressing ataxin-3 fragments with expanded polyglutamine stretches, we observed aggregate formation and cell death in cultured BHK-21 cells. The cytotoxic effect of N-terminal-truncated ataxin-3 with the expanded polyglutamine tract was enhanced under serum starvation culture, in which cells were arrested in the G(0)/G(1)phase. Coexpression of p21 (waf1/cip1/sdi1), a cyclin-Cdk inhibitor that induced cell cycle arrest in the G(1)phase, also increased the cell death susceptibility produced by the mutant ataxin-3 fragment in BHK-21 cells. The elevated susceptibility to cell death in the G(0)/G(1)phase was confirmed in nerve growth factor-treated, postmitotic neuronal PC12 cells compared with undifferentiated proliferating PC12 cells. These results strongly suggest that the cellular toxicity of truncated ataxin-3 with an expanded polyglutamine stretch is enhanced by cell cycle arrest in the G(0)/G(1)phase. Mutant ataxin-3 may confer a higher susceptibility to cell death on cells in the G(0)/G(1)phase.

Animals↗
PubMed2000

Role of caspase-1 subfamily in cytotoxic cytokine-induced oligodendrocyte cell death.

Oligodendrocytes are myelin forming cells in mammalian central nervous system. About 50% of oligodendrocytes (OLGs) undergo cell death in normal development. In addition, OLG cell deaths have been observed in demyelinating diseases including multiple sclerosis (MS). Clinical observations and in vitro cell culture studies have suggested that cytokines mediate OLG cell damage in multiple sclerosis (MS). Among the cytokines, tumor necrosis factor (TNF) is thought to be one of the mediators responsible for the damage of OLGs in MS. The administration of TNF-alpha to primary cultures of OLGs induced DNA fragmentation, and significantly decreased the number of live OLGs. Chemical inhibitors Ac-YVAD-CHO (a specific inhibitor of caspase-1 (ICE)-like proteases) enhanced the survival of TNF-alpha treated OLGs better than Ac-DEVD-CHO (a specific inhibitor of caspase-3 (CPP32)-like proteases). These results indicate that caspase-1-mediated cell-death pathway are activated in TNF-induced OLG cell death. Caspase-11 is involved in activation of caspase-1. Oligodendrocytes from caspase-11-deficient mice are partially resistant to TNF-induced OLG cell death. Our results suggest that the inhibition of caspase-1 sufamily may be a novel therapeutic approach to treat MS.

Animals↗
PubMed2000

Increased amyloid beta protein in the skin of patients with amyotrophic lateral sclerosis.

Distinct vascular and periadnexal immunoreactivity have been observed for amyloid b protein (Abeta) in skin from patients with amyotrophic lateral sclerosis (ALS). We used an enzyme-linked immunosorbent assay to make a more quantitative comparison of Abeta concentrations between ALS patients and controls. The insoluble fractions of skin samples from ALS patients contained significantly higher Abeta concentrations per milligram protein than those from controls. Various alterations in extracellular matrix components have been reported to occur in the skin of patients with ALS, and several matrix constituents have been shown to affect processing and aggregation of Abeta in human brain. Taking these previous findings together with those of the present study, our observations suggest that changes in extracellular matrix in skin of ALS patients may facilitate aggregation and deposition of Abeta.

Amyloid beta-Peptides↗
PubMed2000

Immunohistochemical staining of dystrophin on formalin-fixed paraffin-embedded sections in Duchenne/Becker muscular dystrophy and manifesting carriers of Duchenne muscular dystrophy.

We succeeded in immunostaining of monoclonal anti-dystrophin antibodies on formalin-fixed and paraffin-embedded muscle sections from patients with Duchenne muscular dystrophy, patients with Becker muscular dystrophy, and manifesting carriers of Duchenne muscular dystrophy using Catalyzed Signal Amplification(TM) system. The Catalyzed Signal Amplification system is an extremely sensitive immunohistochemistry staining procedure based on the peroxidase-catalyzed deposition of a biotinylated phenolic compound. We used three mouse monoclonal antibodies: DYS1, DYS2, and DYS3. Muscle sections were treated using the Target Retrieval Solution(TM) and the Catalyzed Signal Amplification system. In control patients, DYS1 and DYS2 were stained at the sarcolemma, but DYS3 remained unstained. In Duchenne muscular dystrophy patients, DYS1 and DYS2 staining were undetected. In Becker muscular dystrophy patients, the immunolabeling of DYSI and DYS2 were weak and discontinuous. In manifesting carriers of Duchenne muscular dystrophy, DYS1 and DYS2 staining showed a mosaic pattern of dystrophin-positive fibers and dystrophin-negative fibers. DYS1 and DYS2 staining patterns of this study are similar to those of frozen sections using conventional methods previously reported. In cases from whom frozen muscle sections cannot be obtained, immunohistochemical dystrophin analysis using the Catalyzed Signal Amplification system will be beneficial for the diagnosis and the screening of neuromuscular diseases.

3,3'-Diaminobenzidine↗
PubMed2000

Effects of human lung fibroblasts on eosinophil degranulation.

BACKGROUND: Although eosinophils and fibroblasts are thought to contribute to the mechanisms of chronic asthmatic inflammation, the interaction between eosinophils and fibroblasts has not been thoroughly clarified. We examined eosinophil cationic protein (ECP) release from human eosinophils cultured in the presence of human lung fibroblast HFL-1. METHODS: Eosinophils from healthy donors were cultured with or without C5a for 16 h in the presence of human fetal lung fibroblasts which had previously been incubated with or without TNF for 4 h. ECP in supernatants was measured by RIA. RESULTS: ECP release was potentiated only when both eosinophils and fibroblasts were activated by C5a and TNF, respectively, while it was not significantly potentiated when either eosinophils or fibroblasts were activated. Paraformaldehyde fixation of fibroblasts had some suppressive effect on ECP enhancement, and mAb against GM-CSF partly inhibited ECP enhancement. Coculture of eosinophils and fibroblasts with stimulus treatment resulted in the enhancement of both eosinophil adhesion and ECP release. The potentiation of ECP release was partially inhibited by anti-ICAM-1 mAb, anti-CD18 mAb, and anti-CD29 mAb, which caused partial and comparable inhibition of the enhancement of eosinophil adhesion. CONCLUSIONS: This study suggests that the activation of fibroblasts may have some role in the potentiation of ECP release from cocultured eosinophils, and that adhesion of eosinophils to fibroblasts may partly be involved in the mechanism of ECP potentiation.

Antibodies, Monoclonal↗
PubMed2000

Ataxic form of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

We reported a 64-year-old male with an eight-month history of gait disturbance and sensory impairment. The patient initially noticed unsteadiness of gait and numbness in his feet, and these symptoms progressed until he was unable to walk without assistance five months later. Vibratory sensation and position sense were markedly diminished, and deep tendon reflexes were absent in all extremities. Motor conduction velocities were slow with prolonged distal latencies, and sensory nerve action potentials (SNAP) were not elicited. Sural nerve biopsy revealed a mild loss of myelinated fibres and segmental demyelination. Cerebrospinal fluid showed normal cell count with protein 526 mg/dL. Anti-GM1, anti-GM2 and anti-GA1 antibodies in serum were positive. We diagnosed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) presenting ataxia. Steroid therapy provided immediate improvement of symptoms and signs. This case suggests that CIDP should be considered as one of the potential causes of ataxic neuropathy.

Ataxia↗
PubMed2000

Canal enlargement by Er:YAG laser using a cone-shaped irradiation tip.

To solve the problem of mechanical instrumentation, we developed a cone-shaped laser irradiation tip. This tip delivers 80% of the energy of the laser laterally and 20% of the energy forward. The tip was equipped with a water nozzle. The aim of this study was to examine the effect of Er:YAG laser irradiation using this tip on root canal enlargement and debridement. As a root canal model, a hole (0.5 x 5 mm) was drilled into a bovine dentin block. The tip was inserted into this hole and moved from the apex to the orifice (45 mm/min). The power of 10 mJ x 10 pps caused enlargement of the canal dimension by 106.5%. 20 and 40 mJ x 10 pps caused enlargements of 116.3 and 118.6%. 30 mJ x 10 pps caused the biggest change (129.8%). Scanning electron microscopic observations indicated that the dentin surface after laser preparation appeared cleaner than that obtained after preparation by drilling. This technique may have the advantage of decreasing the preparation time.

Animals↗
PubMed2000

Factors determining clockwise and counterclockwise conduction patterns in atrial reentrant tachycardias: a rabbit model of atrial flutter.

INTRODUCTION: In the development of atrial flutter due to reentry, the crista terminalis is supposed to pose a conduction barrier, but the role of its longitudinal conduction in determining the propagation pattern of the reentrant impulse is not known. In rabbit right atrial preparations, we induced reentrant atrial tachycardias and examined the effects of transverse section of the crista terminalis on the development and conduction patterns of arrhythmias. METHODS AND RESULTS: Right atrial preparations from 12 albino rabbits were placed endocardial surface down in a chamber with an array of 48 bipolar electrodes to draw activation maps. A single premature stimulus was delivered to induce tachycardias at the free wall. In the control, five instances of tachycardia per preparation were induced and another five were induced after cutting the crista terminalis. In the control, the mean duration of tachycardia was 127.1+/-25.2 seconds. The tachycardia was counterclockwise in 39 of 60 instances, clockwise in 12, and undetermined in 4 defined as "atypical." After transverse section of the crista terminalis, the duration was prolonged to 372.6+/-30.4 seconds, but the conduction patterns were not changed. In the free wall, counterclockwise reentry had a broader wavefront and faster conduction than clockwise reentry. CONCLUSION: Longitudinal conduction block at the crista terminalis contributed to maintenance of reentrant atrial tachycardias, but had no influence on their propagation patterns. Clockwise and counterclockwise rotation of impulses in reentrant tachycardias had different paths and velocities of the wavefront in the free wall of the right atrium.

Animals↗
PubMed2000

Hyperglycemia exacerbates the effect of ischemia-reperfusion on peripheral nerve in rat.

Ischemia-reperfusion is known to induce generation of oxygen free radicals (OFRs), thereby resulting in tissue damage. To clarify the pathogenesis of diabetic neuropathy, we examined whether hyperglycemia exacerbates the effects of ischemia-reperfusion on peripheral nerves. Using light microscopy, characteristic pathological changes seen in myelin and axons of nerve fibers were classified into two types: "loose myelin" and "dark axon," respectively. After a 2-hour ischemia and 24-hour reperfusion of sciatic nerves of rats, the concentrations of lipid peroxide and "loose myelin" in the nerves were significantly increased in the diabetic rats, but not in the nondiabetic rats. Thereafter, "dark axon" was significantly increased in both diabetic and nondiabetic rats. "Loose myelin" may be increased as a result of the effects of OFRs produced by ischemia-reperfusion, which are exacerbated by hyperglycemia.

Animals↗
PubMed2000

[Subcutaneous sarcoidosis of the extremities].

A 65-year-old man was referred to our hospital due to abnormal chest roentgenograms showing bilateral hilar enlargement with diffuse micronodular opacities. He presented with uveitis and elevated serum ACE and tested negative for tuberculin response. Transbronchial lung biopsies as well as bronchoalveolar lavage were performed and yielded a diagnosis of sarcoidosis. Several months later, the patient showed multiple subcutaneous nodules around the knee joints and elbow joints with exacerbation of intrapulmonary lesions. A skin biopsy revealed multiple foci of typical non-caseating epithelioid cell granulomata. These pulmonary and subcutaneous lesions rapidly resolved in response to the systemic administration of corticosteroids. Subcutaneous sarcoidosis may be a subacute variant of sarcoidosis associated with systemic involvement.

Aged↗
PubMed2000

Grafting of stomach tissue into the duodenum in F344 rats results in chimeric crypts and tumor development.

Gastric tissue was transplanted from the fundic and pyloric mucosa of 8-week old female F344 rats into the duodenum of males. Autopsy, 12 months after the operation, revealed grafts associated with persistent stones in the duodenum and/or calcification in the tissue. Pepsinogen positive chimeric glands with goblet cells also appeared in the grafts which gave rise to tumors in 18 out of 45 animals (40%). In conclusion, stomach grafts re-differentiate into intestine with goblet cells in the duodenum and this process predisposes to tumor development.

Animals↗
PubMed2000

A case with myasthenia gravis (MG) emerging after splenectomy for idiopathic thrombocytopenic purpura (ITP): possible effects of thymectomy on autoantibodies.

The combination of idiopathic thrombocytopenic purpura (ITP) and myasthenia gravis (MG) has been reported infrequently. We report here the development of MG in a patient who underwent splenectomy for ITP ten years earlier, and describe the serum levels of anti-acetylcholine receptor antibodies (anti-AchR) and platelet-associated IgG (PAIgG) followed over 11 years. The concentrations of both autoantibodies have been decreased after thymectomy, suggesting that this procedure is potentially beneficial for treating both MG and ITP.

Adult↗
PubMed1999

A novel compound heterozygote (FAP ATTR Arg104His/ATTR Val30Met) with high serum transthyretin (TTR) and retinol binding protein (RBP) levels.

A 64-year-old Japanese male suffering from very slowly progressive amyloidosis was studied by immunohistopathologic, mass spectrometric, and molecular genetic methods. After confirming the immunoreactivity of transthyretin (TTR) in the amyloid deposits using an anti-TTR polyclonal antibody, matrix-assisted laser desorption ionization/time-of-flight-mass spectrometry (MALDI/TOF-MS) was employed to look for the presence of variant TTR(s) in the serum. Two variant forms of TTR, one with a molecular weight 32 Da greater and another with a molecular weight 19 Da less than that of normal TTR encoded by the two respective alleles, were detected in this patient. Direct sequence analysis confirmed the presence of a double substitution: one at codon 30 from GTG (Val) to ATG (Met) and the other at codon 104 from CGC (Arg) to CAC (His) in the two alleles. MALDI/TOF-MS of the parents of the proband revealed that his father was a heterozygote of ATTR Arg104His and his mother was a heterozygote of ATTR Val30Met. The total TTR and retinol binding protein (RBP) concentrations in the serum samples of the proband were very high compared with those of FAP ATTR Val30Met patients and control subjects. We report here a new compound heterozygote in the TTR gene with familial amyloidotic polyneuropathy (FAP).

Acetaldehyde↗