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Biomedical subjects

M Toyoshima

Publications and source records attributed to M Toyoshima.

At least 19 recordsLinked to original sources
PubMed2006

Interstitial lung diseases associated with amyopathic dermatomyositis.

The aim of the present study was to clarify the clinical characteristics and prognosis of patients with interstitial lung disease (ILD) associated with amyopathic dermatomyositis (ILD-ADM). The study consisted of 14 consecutive patients with ILD-ADM. Patients were classified into two categories, acute/subacute and chronic forms, according to the clinical presentation of ILD. The clinical features, responsiveness to therapy, and prognosis between the two forms were compared. Nine ILD-ADM patients were categorised as the acute/subacute form, and five as the chronic form. Arterial oxygen tension was significantly lower in the acute/subacute ILD than chronic ILD patients. On high-resolution computed tomography, ground-glass opacities were frequently found in the two forms, but consolidation was more common in acute/subacute ILD than chronic ILD. Bronchoalveolar lavage analysis showed higher numbers of total cells and lymphocytes in acute/subacute ILD than chronic ILD. Histologically, the most common finding was nonspecific interstitial pneumonia in the two forms, while diffuse alveolar damage was only found in acute/subacute ILD. Acute/subacute ILD was generally resistant to therapy, while chronic ILD responded well. Notably, the mortality of acute/subacute ILD was much higher than that of chronic ILD (67 versus 0%, respectively). In conclusion, interstitial lung disease associated with amyopathic dermatomyositis includes two different forms, the acute/subacute and chronic forms, with distinct prognoses.

Acute Disease↗
PubMed2006

Suppression of replication fork progression in low-dose-specific p53-dependent S-phase DNA damage checkpoint.

The S-phase DNA damage checkpoint is activated by DNA damage to delay DNA synthesis allowing time to resolve the replication block. We previously discovered the p53-dependent S-phase DNA damage checkpoint in mouse zygotes fertilized with irradiated sperm. Here, we report that the same p53 dependency holds in mouse embryonic fibroblasts (MEFs) at low doses of irradiation. DNA synthesis in p53 wild-type (WT) MEFs was suppressed in a biphasic manner in which a sharp decrease below 2.5 Gy was followed by a more moderate decrease up to 10 Gy. In contrast, p53-/- MEFs exhibited radioresistant DNA synthesis below 2.5 Gy whereas the cells retained the moderate suppression above 5 Gy. DNA fiber analysis revealed that 1 Gy irradiation suppressed replication fork progression in p53 WT MEFs, but not in p53-/- MEFs. Proliferating cell nuclear antigen (PCNA), clamp loader of DNA polymerase, was phosphorylated in WT MEFs after 1 Gy irradiation and redistributed to form foci in the nuclei. In contrast, PCNA was not phosphorylated and dissociated from chromatin in 1 Gy-irradiated p53-/- MEFs. These results demonstrate that the novel low-dose-specific p53-dependent S-phase DNA damage checkpoint is likely to regulate the replication fork movement through phosphorylation of PCNA.

Animals↗
PubMed2006

Involvement of M(2) muscarinic receptors in relaxant response of circular muscle of mouse gastric antrum.

Our previous study showed that atropine significantly inhibited the sustained relaxation induced by electrical field stimulation (EFS) in the circular muscle strips prepared from the mouse antrum, and that pituitary adenylate cyclase activating peptide (PACAP) partially mediated the sustained relaxation. The muscarinic receptor subtype associated with the sustained relaxation was examined in the present study by using each muscarinic receptor subtype of knockout (KO) mice. EFS-induced sustained relaxation in the antrum prepared from M(2) receptor KO mice was significantly less than that of wild-type mice. Atropine failed to inhibit this relaxation. On the other hand, similar sustained relaxation and inhibitory effects of atropine to those of wild-type mice were observed in M(1), M(3) and M(4) receptor KO mice. Exogenously added PACAP-27 relaxed the antral strips of wild-type and M(2) receptor KO mice to a similar extent. Immunohistochemical study revealed that M(2) receptor immunoreactivity was localized with PACAP-immunoreactivity in enteric neurons within the antrum of wild-type mice. In contrast, atropine did not affect the EFS-induced sustained relaxation in the gastric fundus. These results suggest that M(2) receptors modulate the sustained relaxation, probably through the regulation of PACAP release, in the mouse antrum.

Animals↗
PubMed2001

Expression of three extracellular matrix degradative enzymes in bladder cancer.

The relationship between expression of extracellular matrix degradative enzymes, angiogenesis and survival of multistage bladder cancer was determined. Expression of 3 extracellular matrix degradative enzymes (metalloproteinase-2, -9 and heparanase) and microvessel formation were examined in 40 resected bladder cancer specimens by immunohistostochemic staining, and then the association of the enzyme expression with angiogenesis and various stages of cancer was investigated. Heparanase protein expression in muscular invasive or lymph-node metastatic cancer was significantly higher than in superficial or nonmetastatic cancer, respectively (69% vs. 8%, p < 0.001, and 80% vs. 40%, p = 0.028, respectively). Interestingly, heparanase was expressed at much higher levels than matrix metalloproteinase-2 and -9. The mean microvessel count in cancers with heparanase expression was significantly higher than that in cancers without heparanase expression (32.3 +/- 18.2 vs. 5.5 +/- 6.1, p = 0.0008). The microvessel formation was not associated with the expression of matrix metalloproteinase-2 and -9. The cancer-specific and overall survival rates of patients with heparanase expression were significantly lower than those of patients without it (p = 0.0001 and p = 0.0008, respectively). Multivariate analysis showed that heparanase expression was a significantly independent prognostic factor for both cancer-specific (p = 0.0047) and overall survival (p = 0.0200). Our study suggested that heparanase plays important roles in invasion, angiogenesis and metastasis of bladder cancer, and thus, this molecule could be a new molecule to inhibit invasion, angiogenesis and metastasis of bladder cancer. Moreover, our results indicate that expression of heparanase could be a new prognostic factor of this disease.

Adult↗
PubMed2001

Wegener's granulomatosis responding to antituberculous drugs.

We present a case of Wegener's granulomatosis (WG) that responded to antituberculous drugs. A 44-year-old woman with multiple nodules on chest radiograph received a diagnosis of pulmonary tuberculosis because open-lung biopsy specimens showed caseous granulomas. Her chest shadows underwent repeated resolution after the start of antituberculous treatment, and relapse after the cessation of the drugs. Antineutrophil cytoplasmic antibody was positive (14 enzyme-linked immunosorbent assay units), and the second lung biopsy specimens showed necrotizing granulomas and vasculitis without pathogenic organisms. Thus, the patient received a diagnosis of WG and was successfully treated with trimethoprim/sulfamethoxazole 10 years after her initial evaluation. Antituberculous drugs were effective in this case of WG.

Adult↗
PubMed2001

[Mitochondrial DNA T to G mutation 8993 in Leigh encephalopathy and organic aciduria].

We report a 10-month-old female infant with Leigh encephalopathy caused by a T to G mutation at nucleotide 8993 of mitochondrial DNA. Initial manifestations were diarrhea and pyrexia, followed by disturbance of consciousness. Blood chemistry showed lactic acidosis, and cranial T2 weighted magnetic resonance imaging demonstrated symmetric high-intensity areas in the basal ganglia, consistent with Leigh encephalopathy. Analysis of urinary organic acids revealed a increase of alpha-ketoglutamate. Derivatives of branched chain amino acids, which accumulate in maple syrup disease, were also increased. Lipoamide dehydrogenase (E3) deficiency was initially suspected; however, normal activity of pyruvate dehydrogenase complex excluded the diagnosis. The organic aciduria disappeared after two weeks. The CNS lesions in our case were observed more prominently in the floor of the bilateral frontal lobes than in the globus pallidus and putamen. In this case, mitochondrial DNA mutation may have caused organic aciduria and the atypical imaging findings.

DNA, Mitochondrial↗
PubMed2001

Heparanase protein and gene expression in bladder cancer.

PURPOSE: We determined the association of heparanase protein and messenger (m)RNA expression with bladder cancer invasion and metastasis. MATERIALS AND METHODS: The expression of heparanase protein and mRNA was assessed by immunohistochemical staining and in situ hybridization, respectively, in 67 bladder cancer specimens resected at various stages of disease. To our knowledge this is the first systematic study of heparanase protein and mRNA expression in human bladder cancer. RESULTS: The expression of heparanase protein in muscular invasive bladder cancer was significantly higher than in superficial cancer (68% versus 19%, p = 0.0001). It was higher in the primary tumor of patients with lymph node metastatic cancer than those with nonmetastatic cancer (80% versus 37%, p = 0.0006). In high grade disease it was significantly higher than in low grade disease (79% versus 29%, p = 0.0001). The expression of heparanase mRNA was also significantly higher in stage pT3 or greater than in stage pT2 or less bladder cancer (96% versus 33%, p = 0.0003). In metastatic N+ cases it was significantly higher than in nonmetastatic bladder cancer (93% versus 46%, p = 0.0037). The heparanase gene and protein showed similar patterns of expression in bladder cancer. CONCLUSIONS: Our study implies that the expression of heparanase protein and mRNA is associated with bladder cancer invasion and metastasis, and heparanase may have a role in disease progression.

Adult↗
PubMed2000

Genomic organization and chromosome localization of the newly identified human heparanase gene.

Heparanase (HPSE), which we have recently isolated, is an endo-beta-D-glucuronidase capable of cleaving heparan sulfate and has been implicated in inflammation and tumor angiogenesis and metastasis. In this report, the genomic organization and chromosome localization of the human heparanase gene is described. Polymerase chain reaction, subcloning and DNA sequencing analysis of a bacterial artificial chromosome (BAC) clone revealed that the 3.7 kb human heparanase cDNA is spread over about 50 kb and contains 14 exons and 13 introns. The heparanase gene is expressed as two mRNA species containing the same open reading frame, HPSE 1a (5 kb) (GenBank Data Library under accession number: AF155510); and HPSE 1b (1.7 kb) (GenBank Data Library under accession number: AF144325), generated by alternative splicing. The HPSE 1a-form contains all 14 exons, whereas in the HPSE 1b-form the first and fourteenth exons (5'- and 3'-untranslated region) have been spliced out. All splice sites conform to the GT-AG rule, except for the splice donor site of intron 13 (which is GA instead of GT), and the splice acceptor of intron 13 (which is GG instead of AG). Fluorescence in situ hybridization and radiation hybrid mapping suggest that the heparanase gene is located on human chromosome 4q22. This report regarding the structure of the human heparanase gene will aid in understanding the genetic contribution of this gene to normal physiology as well as to disease states. A possible involvement of heparanase in neuronal degeneration is discussed.

Alternative Splicing↗
PubMed2000

Flexible synthesis and biological activity of uronic acid-type gem-diamine 1-N-iminosugars: a new family of glycosidase inhibitors.

An efficient and flexible synthetic route to four gem-diamine 1-N-iminosugars of uronic acid-type (D-glucuronic, D-mannuronic, L-iduronic, and L-guluronic acid), a new family of glycosidase inhibitor, from l-galactono-1,4-lactone have been developed in an enantiodivergent fashion through a sequence involving as the key steps (a) the formation of gem-diamine 1-N-iminopyranose ring by the Mitsunobu reaction of an aminal and (b) the introduction of a carboxylic acid group by the Wittig reaction of a ketone, hydroboration and oxidation, and the Sharpless oxidation. D-Glucuronic and D-mannuronic acid-type 1-N-iminosugars, (3S,4R,5R, 6R)- and (3S,4R,5R,6S)-4, 5-dihydroxy-6-trifluoroacetamido-3-piperidinecarboxylic acid, were proven to be potent inhibitors for beta-D-glucuronidase (IC(50) 6.5 x 10(-)(8)M) and to affect human heparanase (endo-beta-glucuronidase).

Animals↗
PubMed2000

Minimally invasive lung and pleural biopsies using 2-mm and standard thoracoscopic equipment.

Videoendoscopic surgery is commonly used to obtain a definitive diagnosis in a patient with pleural lesions or pulmonary infiltration of unknown etiology. We have performed minimally invasive pleural and lung biopsies, using 2-mm mini-videoscopic instruments supported by standard thoracoscopy via one 11.5-mm port, in 10 patients. These involved 8 patients with diffuse pulmonary infiltration, and two with diffuse pleural thickening. They underwent thoracoscopic pulmonary wedge resection and pleural biopsy using one 11.5-mm port and two or three 2-mm mini-ports. The mean operating time was 37 minutes. This procedure was successful in establishing a definitive diagnosis in each patient. Complications included subacute acceleration in pulmonary infiltration in one patient. No patient complained of pain or discomfort at the 2 mm-thoraco port sites. Healing of this port site resulted in excellent cosmesis. Mini-videoscopic surgery supported by standard thoracoscopic equipment can be used to perform lung or pleural biopsy less invasively than standard thoracoscopic approach.

Aged↗
PubMed2000

Antigen uptake and subsequent cell kinetics in bronchus-associated lymphoid tissue.

OBJECTIVE: Bronchus-associated lymphoid tissue (BALT) plays an important role in the immunological defence of airways. However, the mechanisms of BALT development, antigen sampling, and subsequent cell kinetics remain unclear. To clarify these chronological processes, we used a Pseudomonas aeruginosa-exposed mouse model. METHODOLOGY: In BALB/c and C57BL/6 mice, BALT development was induced by inhalation of heat-killed P. aeruginosa after sensitization with subcutaneous injection of P. aeruginosa in the presence of Freund's complete adjuvant. Subsequently, we chronologically killed these mice who had inhaled PKH26-labelled P. aeruginosa and examined bacterial transport using fluorescence microscopy. The distribution of interleukin-4-positive cells and interferon-gamma-positive cells was studied immunohistochemically. RESULTS: The degree of BALT hyperplasia was greater in sensitized mice than in non-sensitized mice and in BALB/c mice than in C57BL/6 mice. PKH26-labelled bacteria were found in BALT earlier in sensitized mice than in non-sensitized mice. Immunohistochemical studies revealed that interleukin-4-positive cells predominated over interferon-gamma-positive cells in the peripheral areas of lymphoid follicles. CONCLUSION: These results indicate that administered antigens are actively transported into BALT and that sensitized Th2 lymphocytes play an important role in forming and maintaining BALT.

Animals↗
PubMed2000

[Testicular sarcoidosis].

We report a rare case of testicular sarcoidosis. A 68-year-old man was admitted for detailed examination of uveitis and swelling of the testes. A chest X-ray film and computed tomographic scans disclosed ground-glass shadows in the lower fields of both lungs with mediastinal lymphadenopathy. Ga scintigram showed pronounced accumulations in the testes, hilum, and mediastinum. Transbronchial lung and testicular biopsy specimens demonstrated noncaseating epithelioid granulomas, thus confirming the diagnosis of sarcoidosis with testicular involvement. The patient was followed up without systemic steroids. A review of the world literature found only 12 reported cases of clinically evident testicular sarcoidosis.

Aged↗
PubMed2000

[Human heparanase: roles in invasion and metastasis of cancer].

Heparanase, which is an extracellular matrix degradative enzyme, degrades heparan sulfate and heparan sulfate proteoglycans, which are chief components of extracellular matrix and vascular basement membrane. The gene structure of this enzyme was recently determined. The biological functions of this enzyme in vivo were as follows: 1) this enzyme accelerates cancer cell invasion and metastasis though the degradation of vascular basement membrane and extracellular matrix by cancer cells; 2) this enzyme releases and activates heparin-binding growth factors such as bFGF and VEGF from heparan sulfate proteoglycans, and induces angiogenesis; 3) the degradative products of heparan sulfate proteoglycans by this enzyme suppress the biological function of activated T-lymphocytes. Therefore, heparanase is thought to be a favorable molecule for acceleration of cancer invasion and metastasis. The expression of heparanase is strongly correlated with the metastasis of melanoma and fibrosarcoma. Thus, heparanase may play important roles in invasion and metastasis of cancer.

Animals↗
PubMed1999

Human heparanase. Purification, characterization, cloning, and expression.

Heparan sulfate and heparan sulfate proteoglycans are present in the extracellular matrix as well as on the external cell surface. They bind various molecules such as growth factors and cytokines and modulate the biological functions of binding proteins. Heparan sulfate proteoglycans are also important structural components of the basement membrane. Heparanase is an endo-beta-D-glucuronidase capable of cleaving heparan sulfate and has been implicated in inflammation and tumor angiogenesis and metastasis. In this study, we report the purification of a human heparanase from an SV40-transformed embryonic fibroblast cell line WI38/VA13 by four sequential column chromatographies. The activity was measured by high speed gel permeation chromatography of the degradation products of fluorescein isothiocyanate-labeled heparan sulfate. The enzyme was purified to homogeneity, yielding a peptide with an apparent molecular mass of 50 kDa when analyzed by SDS-polyacrylamide gel electrophoresis. Using the amino acid sequences of the N-terminal and internal heparanase peptides, a cDNA coding for human heparanase was cloned. NIH3T3 and COS-7 cells stably transfected with pBK-CMV expression vectors containing the heparanase cDNA showed high heparanase activities. The homology search revealed that no homologous protein had been reported.

Amino Acid Sequence↗
PubMed1999

Cellular senescence of angiofibroma stroma cells from patients with tuberous sclerosis.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by epilepsy, mental retardation and hamartomatous lesions in multiple organs. It has been shown that the genes responsible for TSC, TSC1 and TSC2, act as tumor suppressors, but the mechanism of hamartomatous growth in several tissues is not completely understood. The TSC hamartomas are essentially benign and they rarely progress to malignant tumors. In this report, we cultured the angiofibroma stroma cells of three adult TSC patients and compared these cells with normal skin fibroblasts for their proliferative capacity, cell morphology and mitotic cycle using a stain for microtubules and the expression of the senescent associated beta-galactosidase (SA beta-Gal). Cultured angiofibroma stroma cells from TSC patients displayed several characteristics observed in human senescent fibroblasts; a low proliferative capacity, an increase in cell size, increased binucleated cells in association with abnormal cytokinesis and increased SA beta-Gal positives. Growth of facial angiofibromas in TSC may be caused by a gain in enhanced sensitivity toward some of the potential mitogens and forced multiplication without loss of the cellular senescent program; this may be the reason why TSC hamartomas rarely progress to malignancy and why the growths are limited to a finite size.

Adult↗
PubMed1999

Biased T cell receptor Vbeta gene expression in bronchoalveolar lavage fluid from Japanese patients with sarcoidosis.

OBJECTIVE: Sarcoidosis is believed to be one of the T cell-mediated granulomatous diseases with unknown aetiology. We attempt to search for the causative T cell clones of sarcoidosis. METHODS: We study T cell receptor beta-chain variable region (Vbeta) repertoire in peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis, using semi-quantitative reverse transcriptase-polymerase chain reaction method. The expression of 22 kinds of Vbeta genes is examined in 17 patients with sarcoidosis and nine normal subjects. RESULTS: Compared with control subjects, the group with sarcoidosis exhibits significantly high expressions of the Vbeta2 (P < 0.005, Wilcoxon's test) and Vbeta6 (P = 0.005) genes in BALF. In each BALF sample, the Vbeta2 (P < 0.01, chi2 test) and Vbeta6 (P < 0.01) genes were overexpressed (> 2 SD above the mean value for each Vbeta observed in control subjects) in 11 and 10 of 17 patients with sarcoidosis, respectively. Furthermore, the amino acid sequences of Vbeta6+ complementarity determining region 3 were conserved in one of three patients. There is, however, no disposition of Vbeta gene usage in PB from patients with sarcoidosis compared with control subjects. CONCLUSIONS: The T lymphocytes with Vbeta2 and/or Vbeta6 are associated with the pathogenesis of sarcoidosis. The possibility exists that these T lymphocytes might be capable of recognizing the restricted antigens, thereby inducing oligoclonal expansion.

Adult↗