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Biomedical subjects

Mitsuhiro Osame

Publications and source records attributed to Mitsuhiro Osame.

At least 73 records · Page 4Linked to original sources
PubMed2003

Clinical and pathological studies of familial amyotrophic lateral sclerosis (FALS) with SOD1 H46R mutation in large Japanese families.

We clarified the clinical and pathological aspects of familial amyotrophic lateral sclerosis (FALS) with SOD1 H46R heterozygous mutation in the Miyakonojo Basin, a region in southern Japan where the prevalence of ALS is 11.4 per 10(5) of the population. We studied 17 patients, including one autopsy case, in three FALS families with the mutation. The average age at disease onset in the families was 44.3+/-8.7 years, and the mean disease duration was 12+/-7.6 years, with a range of 6 to 30 years. Ten of 17 patients were unable to walk by the mean age of 56.4+/-12.2 years. The initial symptom was muscle weakness in the distal leg muscle in all patients. The autopsy findings of one FALS patient showed atrophy of lateral and anterior funiculi, decreased numbers of anterior horn cells, preserved posterior funiculus and absence of neuronal inclusion bodies. Percentages of mutant SOD1 protein measured by mass spectrometry were 14% in erythrocytes, 43% in the spinal cord, 47% in the iliopsoas muscle and 60% in the diaphragm. In this study, we confirmed that FALS with SOD1 H46R mutation showed uniform initial symptoms and slow disease progression with intra-familial variation of disease severity and that inclusion body formation is not essential in FALS with this mutation.

Adult↗
PubMed2003

Capillary changes in skeletal muscle of patients with Ullrich's disease with collagen VI deficiency.

We examined the capillaries in muscle biopsy specimens from two patients with Ullrich's disease with collagen VI deficiency by light and electron microscopy. Collagen VI plays an important role in platelet aggregation for binding von Willebrand factor. Using immunohistochemistry, collagen VI was shown to be absent on capillaries from patients with Ullrich's disease, while von Willebrand factor, collagen IV, and vascular endothelial growth factor were normally expressed. Electron microscopy revealed narrow lumens, large nuclei in endothelial cells, and fenestration of a capillary. The number of pinocytotic vesicles per unit endothelial cytoplasm was increased. The cytoplasm of endothelial cells was strongly stained with uranyl acetate and lead citrate. Replication of the capillary basement membrane was observed. On the other hand, easy bleeding and coagulation were not observed in the two patients. These findings suggested that the collagen VI deficiency might have caused the electron microscopic changes of capillaries, while the function of the capillaries is apparently retained.

Adult↗
PubMed2003

Different cytokine production in tax-expressing cells between patients with human T cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis and asymptomatic HTLV-I carriers.

Human T cell lymphotropic virus type I (HTLV-I) provirus load has been reported to be generally higher in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) than in asymptomatic HTLV-I carriers (ACs). However, some ACs have a high HTLV-I provirus load comparable with that in patients with HAM/TSP. To examine whether other factors influence the outcome of HTLV-I infection in patients with HAM/TSP and ACs, we analyzed spontaneous Tax expression and cytokine production in peripheral blood mononuclear cells using flow cytometry. The Tax expression in HTLV-I-infected cells (percentage of Tax expressing cells/HTLV-I provirus load when assumed 1 copy/cell) and the intensity of Tax expression did not differ between these 2 groups. However, the production of interferon-gamma and tumor necrosis factor-alpha in Tax-expressing cells was significantly lower in ACs with high HTLV-I provirus load than in patients with HAM/TSP. This result suggests that the production of inflammatory cytokines in Tax-expressing cells is one of the factors that contribute to the development of HAM/TSP.

Adult↗
PubMed2003

Human T-cell lymphotropic virus type I (HTLV-I)-related clinical and laboratory findings for HTLV-I-infected blood donors.

Clinical and laboratory findings were examined for 111 human T-cell lymphotropic virus type I (HTLV-I)-infected blood donors. HTLV-I provirus loads in subjects with a family history of adult T-cell leukemia (ATL) or HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) tended to be higher than those in subjects without a family history of these conditions. There were 3 asymptomatic patients with ATL, 4 with a history of uveitis, 7 with hyperreflexia in the lower limbs, and 3 with urinary frequency in the night. The mean CD4 cell/CD8 cell ratio +/- SD was significantly lower (p<.0001) in subjects with hyperreflexia in the lower limbs (1.3 +/- 0.2) than in subjects without any clinical abnormalities (1.7 +/- 0.6), suggesting that subjects with hyperreflexia in the lower limbs already have some immunologic abnormalities. The concordance of HTLV-I infection between husband and wife was lower in this study than in a previous study. HTLV-I-related inflammatory symptoms were more frequent (p =.021, Fisher exact test; OR = 9.5; 95% CI, 1.7-53.5) in HTLV-I tax A-infected donors (3 [50%] of 6 donors) than in HTLV-I tax B-infected donors (10 [9.5%] of 105 donors), suggesting different risks of HTLV-I-related symptoms according to the virus genotype.

Adult↗
PubMed2003

Spread of HTLV-I between lymphocytes by virus-induced polarization of the cytoskeleton.

Cell contact is required for efficient transmission of human T cell leukemia virus- type 1 (HTLV-I) between cells and between individuals, because naturally infected lymphocytes produce virtually no cell-free infectious HTLV-I particles. However, the mechanism of cell-to-cell spread of HTLV-I is not understood. We show here that cell contact rapidly induces polarization of the cytoskeleton of the infected cell to the cell-cell junction. HTLV-I core (Gag protein) complexes and the HTLV-I genome accumulate at the cell-cell junction and are then transferred to the uninfected cell. Other lymphotropic viruses, such as HIV-1, may similarly subvert normal T cell physiology to allow efficient propagation between cells.

CD4-Positive T-Lymphocytes↗
PubMed2003

Low frequency of CD94/NKG2A+ T lymphocytes in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis, but not in asymptomatic carriers.

Human natural killer (NK)-cell receptors are expressed by NK cells and some T cells, primarily TCR+CD8+ cytotoxic T lymphocytes (CTLs). Inhibitory NK cell receptors (iNKRs) can down-regulate antigen-mediated T-cell effector functions, including cytotoxic activity and cytokine release. In the present study we demonstrate that CD3+ T cells that bind tetramers of HLA-E and express its ligand, the NK-cell inhibitory receptor CD94/NKG2A, were significantly decreased in frequency in patients with human T-cell lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) but not in asymptomatic HTLV-1 carriers. These cells were either alphabeta or gammadelta T cells. T-cell receptor (TCR) Vbeta-specific reverse transcription-polymerase chain reaction and spectratyping analysis revealed that the TCR repertoire in directly isolated HLA-E tetramer-positive cells from peripheral blood mononuclear cells was skewed in both HTLV-1-infected and healthy individuals. However, oligoclonally or monoclonally expanded levels of TCR Vbetawere more frequently detected within HTLV-1-infected individuals than healthy controls. Importantly, HLA-E tetramer-positive or NKG2A+ T cells from HTLV-1 patients do not express Tax and display different TCR usage from the immunodominant Tax11-19-specific CD8+ T cells, suggesting that they do not encounter HTLV-1-infected cells. The expression of NK cell-associated receptors by clonally expanded CD8+ T cells during chronic viral infection suggests that these receptors play a role in regulating CD8+ T cell-mediated antiviral immune responses and that a decrease of this cell subset results in an increased risk of inflammatory diseases such as HAM/TSP.

Antigens, CD↗
PubMed2003

Pathological characteristics of skeletal muscle in Ullrich's disease with collagen VI deficiency.

Patients with Ullrich's disease have generalized muscle weakness, multiple contractures of the proximal joints and hyperextensibility of the distal joints. Recently, we found a deficiency of collagen VI protein in skeletal muscle from two patients with Ullrich's disease. In this study, we investigated immunohistochemically the expression of extracellular matrix proteins and various proteins, which are markers for regenerating muscle fibers. Although we have detected the reduction of collagen VI in Ullrich's disease with the two kinds of monoclonal antibodies for the different domains of collagen VI, the remaining immunoreactive material was different between them. This might suggest the presence of incomplete collagen VI protein in the muscle fibers. Furthermore, we found that very small muscle fibers in the patients with Ullrich's disease showed marked expression of desmin, neural cell adhesion molecule and neonatal myosin heavy chain, which is a characteristic finding of regenerating fibers, however, they showed poor expression of developmental myosin heavy chain and thrombomodulin. The present findings suggest that abnormal regeneration or maturation processes are involved in the pathogenesis of dystrophic muscle changes at least in the advanced stage of Ullrich's disease.

Adult↗
PubMed2003

Usefulness of proviral load measurement for monitoring of disease activity in individual patients with human T-lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis.

High human T-lymphotropic virus type I (HTLV-I) proviral load in peripheral blood mononuclear cells (PBMCs) has been reported in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and the proviral load has been reported to fluctuate in individual patients during the course of the disease. Clinical symptoms usually became stable after a prolonged period of symptom progression. However, the authors have experienced having some patients whose clinical manifestations suddenly became worse during the course of the disease. To clarify the role of high proviral load and its fluctuation in the pathogenesis of HAM/TSP, the authors measured the proviral load of serially taken PBMCs as well as of cerebrospinal fluid (CSF) cells from patients with HAM/TSP on long-term follow-up and compared these with their clinical manifestations. There was a wide distribution of proviral load, from 0.3 to 37.8 copies/100 PBMCs; however, the proviral load in individual patients was relatively stable during the course of the disease. Eighty-three percent of the patients with clinical worsening showed an increase in proviral load at the time point when clinical worsening was recorded, or at the preceding time point. The proviral loads in CSF cells were higher than those in PBMCs in individual patients. The ratio of proviral loads in CSF cells/in PBMCs, but not the absolute load, in either compartment, was significantly associated with clinically progressive disease and with recent onset of HAM/TSP. These findings indicate that clinical progression of HAM/TSP is associated with increased proliferation or immigration of HTLV-I-infected lymphocytes in the central nervous system.

Aged↗
PubMed2003

Human T-cell lymphotropic virus type I and neurological diseases.

Human T-cell lymphotropic virus type I (HTLV-I) infection is associated with a variety of human diseases. In particular, there are two major diseases caused by HTLV-I infection. One is an aggressive neoplastic disease called adult T-cell leukemia (ATL), and another is a chronic progressive inflammatory neurological disease called HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It is still unknown why one virus causes these different diseases. With regard to HAM/TSP, virus-host immunological interactions are an considered to be important cause of this disease. Coexisting high HTLV-I proviral load and HTLV-I-specific T cells (CD4+ T cells and CD8+ T cells) is an important feature of HAM/TSP. Histopathological studies indicate the existence of an inflammatory reaction and HTLV-I-infected cells in the affected lesions of HAM/TSP. Therefore, the immune response to HTLV-I probably contributes to the inflammatory process of the central nervous system lesions in HAM/TSP patients.

HTLV-I Infections↗
PubMed2003

Predictive value of serial platelet count and VEGF determination for the management of DIC in the Crow-Fukase (POEMS) syndrome.

We report a case of a 62-year-old man diagnosed as Crow-Fukase syndrome (POEMS syndrome), in which the serial platelet count and vascular endothelial growth factor (VEGF) concentration were determined before and during the state of disseminated intravascular coagulation (DIC). The serum VEGF concentration was noted to be gradually decreased prior to DIC, after which it abruptly decreased with a corresponding drop in platelet count upon the onset of DIC. The physiological effects of VEGF are viewed as one of the causative factors in DIC and its abrupt and excessive release may have caused the exacerbation of the patient's clinical symptoms.

Antithrombins↗
PubMed2003

[A case of aspergillus bronchitis with effective oral itraconazole].

A 62-year-old woman with diabetes mellitus and chronic hepatitis C was admitted to our hospital because of fever and productive cough. A thoracic CT scan demonstrated a cavity in the left upper lobe, thickening of the bronchial walls and multiple subpleural infiltrates. Fiberoptic bronchoscopy revealed aspergillus bronchitis. The patient was treated with 200 mg/day of oral itraconazole, but no effect was seen. Treatment with 300 mg/day of oral itraconazole, however, resulted in improvement of the symptoms and resolution of the radiographic abnormalities. We report a rare case of aspergillus bronchitis.

Administration, Oral↗
PubMed2002

Degenerate specificity of HTLV-1-specific CD8+ T cells during viral replication in patients with HTLV-1-associated myelopathy (HAM/TSP).

Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an inflammatory neurologic disease caused by HTLV-1 infection, in which HTLV-1-infected CD4(+) T cells and HTLV-1-specific CD8(+) T cells may play a role in the disease pathogenesis. Patients with HAM/TSP have high proviral loads despite vigorous virus-specific CD8(+) T-cell responses; however, it is unknown whether the T cells are efficient in eliminating the virus in vivo. To define the dynamics of HTLV-1-specific CD8(+) T-cell responses, we investigated longitudinal alterations in HTLV-1 proviral load, amino acid changes in an immunodominant viral epitope, frequency of HTLV-1-specific T cells, and degeneracy of T-cell recognition in patients with HAM/TSP. We showed that the frequency and the degeneracy of the HTLV-1-specific CD8(+) T cells correlated well with proviral load in the longitudinal study. The proviral load was much higher in a patient with low degeneracy of HTLV-1-specific T cells compared to that in a patient with comparable frequency but higher degeneracy of the T cells. Furthermore, in a larger number of patients divided into 2 groups by the proviral load, those with high proviral load had lower degeneracy of T-cell recognition than those with low proviral load. Sequencing analysis revealed that epitope mutations were remarkably increased in a patient when the frequency and the degeneracy were at the lowest. These data suggest that HTLV-1-specific CD8(+) T cells with degenerate specificity are increased during viral replication and control the viral infection.

Amino Acid Substitution↗
PubMed2002

Molecular analysis of T cell clonotypes in muscle-infiltrating lymphocytes from patients with human T lymphotropic virus type 1 polymyositis.

Epidemiological studies have shown that a correlation may exist between human T cell lymphotropic virus type 1 (HTLV-1) infection and a form of polymyositis (PM). To characterize muscle-infiltrating lymphocytes (MILs) from patients with HTLV-1 PM, we examined the T cell receptor (TCR) beta-chain variable region repertoire and clonotype of MILs and peripheral blood mononuclear cells (PBMC) from 3 patients, using TCR complementarity-determining region 3 (CDR3) length spectratyping and DNA sequencing. Immunohistochemical studies showed that MILs from patients with HTLV-1 PM contain both CD4(+) and CD8(+) T cells. Although some clonotypes observed in PBMC were also found in MILs in all patients examined, MILs consisted predominantly of locally expanded clones. One clonotype in MILs was derived from human leukocyte antigen (HLA)-A*02/Tax11-19 tetramer-positive cells, the CDR3 motif of which contains amino acid residues for HLA-A*02/Tax peptide-TCR interaction. We conclude that certain T cell clones proliferate in the muscle lesions of HTLV-1 PM and may contribute to the pathogenesis of the disease.

Aged↗
PubMed2002

Polygenic control of human T lymphotropic virus type I (HTLV-I) provirus load and the risk of HTLV-I-associated myelopathy/tropical spastic paraparesis.

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is one outcome of infection with HTLV-I. A population association study of 229 patients with HAM/TSP and 202 healthy carriers of HTLV-I in southern Japan showed that this outcome of HTLV-I infection and the HTLV-I provirus load are under polygenic control. Of 58 polymorphic sites studied in 39 non-HLA candidate gene loci, 3 new host genetic factors that influenced the risk of HAM/TSP or the provirus load of HTLV-I were identified. The promoter TNF -863A allele predisposed to HAM/TSP, whereas SDF-1 +801A 3'UTR, and IL-15 191C alleles conferred protection. Knowledge of HTLV-I-infected individuals' ages, sex, provirus load, HTLV-I subgroup, and genotypes at the loci HLA-A, HLA-C, SDF-1, and TNF-alpha allowed for the correct identification of 88% of cases of HAM/TSP in this Japanese cohort.

Alleles↗
PubMed2002

Skeletal muscle abnormalities in two patients with dystonia.

We report two patients with dystonia aged 53 and 27 years. One patient was diagnosed as a sporadic case of primary dystonia. The other patient was diagnosed as having secondary dystonia following head injury. Skeletal muscle specimens were obtained by open biopsy from the two patients. The muscle biopsy specimens showed lobulated fibers, ring fibers, and type 1 fiber atrophy. Dystonia comprises involuntary movement and causes abnormal muscle tone. We considered that the abnormal muscle tone caused by dystonia might be involved in the pathogenesis of these histochemical changes in skeletal muscle.

Adult↗