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Biomedical subjects

M Sugimoto

Publications and source records attributed to M Sugimoto.

At least 19 recordsLinked to original sources
PubMed1995

Isolation and structure of the COL4A6 gene encoding the human alpha 6(IV) collagen chain and comparison with other type IV collagen genes.

The genes COL4A5 and COL4A6, coding for the basement membrane collagen chains, alpha 5(IV) and alpha 6(IV), respectively, are located head-to-head in close proximity on human chromosome Xq22, and COL4A6 is transcribed from two alternative promoters in a tissue-specific fashion (Sugimoto M., Oohashi T., and Ninomiya Y. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 11679-11683). Immunofluorescence studies using alpha chain-specific antibodies demonstrated that the two genes are expressed in a tissue-specific manner (Ninomiya, Y., Kagawa, M., Iyama, K., Naito, L., Kishiro, Y., Seyer, J. M., Sugimoto, M., Oohashi, T., and Sado, Y. (1995) J. Cell Biol. 130, 1219-1229). We report here for the first time the isolation and the structural organization of the human COL4A6 gene. The entire gene presumably exceeds 200 kilobase pairs and contains 46 exons. Exons 1' and 1 encode the two different 5'-UTRs and the two amino-terminal parts of of the signal peptide. The carboxyl part of the signal peptide and the 7 S domain are coded for by the following 6 different exons, 2-7, whereas the exons 7-42 encode the central COL 1 domain, which contains the Gly-X-Y repeats. The last three exons, 43-45, encode the carboxyl-terminal NC1 domain. Sizes of more than a half of the exons of the gene are the same as those of Col4a2 but quite different from those of COL4A5. Within the COL4A6 gene we found three CA repeat markers that can be used for allele detection. The detailed structure of the COL4A6 gene and the high heterozygosity microsatellite markers located within the gene will be useful for linkage analysis and familial diagnosis of diseases caused by mutations of this gene.

Amino Acid Sequence↗
PubMed1995

Differential expression of two basement membrane collagen genes, COL4A6 and COL4A5, demonstrated by immunofluorescence staining using peptide-specific monoclonal antibodies.

Genes for the human alpha 5(IV) and alpha 6(IV) collagen chains have a unique arrangement in that they are colocalized on chromosome Xq22 in a head-to-head fashion and appear to share a common bidirectional promoter. In addition we reported a novel observation that the COL4A6 gene is transcribed from two alternative promoters in a tissue-specific manner (Sugimoto, M., T. Oohashi, and Y. Ninomiya. 1994. Proc. Natl. Acad. Sci. USA. 91:11679-11683). To know whether the translation products of both genes are colocalized in various tissues, we raised alpha 5(IV) and alpha 6(IV) chain-specific rat monoclonal antibodies against synthetic peptides reflecting sequences near the carboxy terminus of each noncollagenous (NC)1 domain. By Western blotting alpha 6(IV) chain-specific antibody recognized 27-kD monomers and associated dimers of the human type IV collagen NC1 domain, which is the first demonstration of the presence in tissues of the alpha 6(IV) polypeptide as predicted from its cDNA sequence. Immunofluorescence studies using anti-alpha 6(IV) antibody demonstrated that in human adult kidney the alpha 6(IV) chain was never detected in the glomerular basement membrane, whereas the basement membranes of the Bowman's capsules and distal tubules were positive. The staining pattern of the glomerular basement membrane was quite different from that obtained with the anti-alpha 5(IV) peptide antibody. The alpha 5(IV) and alpha 6(IV) chains were colocalized in the basement membrane in the skin, smooth muscle cells, and adipocytes; however, little if any reaction was seen in basement membranes of cardiac muscles and hepatic sinusoidal endothelial cells. Thus, both genes are expressed in a tissue-specific manner, perhaps due to the unique function of the bidirectional promoter for both genes, which is presumably different from that for COL4A1 and COL4A2.

Adipocytes↗
PubMed1995

Transforming growth factor-beta 1 coated beta-tricalcium phosphate pellets stimulate healing of experimental bone defects of rat calvariae.

OBJECTIVE: TGF-beta 1-coated beta-TCP pellets were grafted in experimental defects of rat calvariae to study the effects on new bone formation. MATERIALS AND METHODS: The grafted sites were evaluated by light microscopy using hematoxylin-eosin (H-E) staining for histology and detection of alkaline phosphatase (ALPase) and tartrate-resistant acid phosphatase (TRACPase) activities to demonstrate osteoblastic and osteoclastic cells. Confocal laser scanning microscopy (CLSM) was performed for morphometry of newly formed bone. RESULTS: H-E sections showed more new bone formation in sites grafted with TGF-beta 1-coated beta-TCP pellets (experimental sites) than those with beta-TCP pellets only (control sites). TRACPase-positive and ALPase-positive cells at experimental sites were more frequent than at control sites. The bone formation rate calculated by computerized CLSM pixel image analysis showed more new bone formation at the experimental sites than at control sites (3.4 +/- 0.8% vs 9.3 +/- 1.7% on week 2 and 11.8 +/- 2.1% vs 39.8 +/- 10.9% on week 4). CONCLUSION: TGF-beta 1-coated beta-TCP pellets promote new bone formation and may be a useful modality in synthetic bone grafting.

Acid Phosphatase↗
PubMed1995

Chemotactic heterogeneity of eosinophils in idiopathic pulmonary eosinophilia.

Heterogeneity in the chemotactic response of eosinophils to 5 T cell line eosinophilic chemotactic factors (ECFs) was assessed in 5 patients with idiopathic pulmonary eosinophilia. Eosinophils from 2 patients responded to all 5 ECFs (group 1), whereas eosinophils from the other 3 patients responded to ECF-PI 5, PI 6, PI 7 and PI 8 but failed to respond to ECF-PI 9 (group 2). It was further found that group 1 showed an elevated level of lactate dehydrogenase and a positive tuberculin reaction, whereas group 2 showed neither. The effects of steroid therapy on the chemotactic responses of eosinophils were also examined. In group 1, the chemotactic response of eosinophils to ECF-PI 9 was significantly diminished after therapy; in contrast it was elevated in group 2. This change was accompanied by resolution of both clinical symptoms and pulmonary infiltration of eosinophils. These findings suggest that pulmonary eosinophilia can be divided into two types on the basis of eosinophil chemotactic response and laboratory findings. The heterogeneous responses of eosinophils to ECFs may provide a useful marker for classification of pulmonary eosinophilia and evaluation of therapy.

Adult↗
PubMed1995

In vivo proviral burden and viral RNA expression in T cell subsets of patients with human T lymphotropic virus type-1-associated myelopathy/tropical spastic paraparesis.

We used in situ hybridization combined with immunocytochemistry, cell sorting, and the polymerase chain reaction (PCR) to investigate clinical events in three asymptomatic carriers of human T lymphotrophic virus type-1 (HTLV-1) and ten patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The objective was to determine which T cell subset of peripheral blood mononuclear cells (PBMC), CD4 or CD8, were infected by HTLV-1 and the manner in which HTLV-1 proviral DNA was expressed at the level of the single cell. Both CD4-positive and CD8-positive cells of the PBMC from five patients with HAM/TSP were infected with HTLV-1. The proportion of HTLV-1-infected cells was 2.5-40% in the CD4-positive subset and 1.0-65% in the CD8- positive subset, when quantified by PCR using HTLV-1-infected MT2 cells as a positive standard. Proviral DNA of HTLV-1 was expressed in both CD4-positive cells and CD8-positive cells of the PBMC from six patients with HAM/TSP and three asymptomatic HTLV-1 carriers. In patients with HAM/TSP, the proportion of the cells expressing HTLV-1 proviral DNA was 0.02-0.1% in both subsets. In asymptomatic carriers, the expression of HTLV-1 proviral DNA was 0.01-0.02% in the CD4-positive subset and 0.01% in the CD8-positive subset. Therefore, HTLV-1 possessed similar in vivo cellular tropism for both CD4-positive cells and CD8-positive cells and HTLV-1 proviral DNA was expressed in vivo in both circulating T cell subsets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Glutathione S-transferases (GSTs)].

Glutathione S-transferases (GSTs) are a family of multifunctional detoxifying enzymes that catalyse the conjugation of glutathione with large number of compounds bearing an electrophilic center, including carcinogens, and also bind a variety of nonsubstrate ligands. The transferases are widely distributed in the mammalian species and can be grouped into three classes on the basis of subunit composition: alpha (basic), mu (neutral), and pi (acidic). The liver is an organ possessing abundant GST-alpha. GST-mu is also present in the liver and lymphocytes, but this is absent in approximately 50% of the human population. GST-pi (originally found in the placenta) is widely located in the lung, kidney, GI tract, erythrocytes and cancer cells. The present review describes a new nomenclature of human GST isoenzymes and recent investigations of this enzymes, including ours. Implications of each isoenzyme are also discussed.

Animals↗
PubMed1994

Basement membrane and carcinogenesis: ultrastructural observations in the basement membrane of the bladder epithelium in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN).

This study investigated the structural alterations in the basement membrane (BM) of the bladder epithelium in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) using transmission electron microscopy. Following administration of BBN, thickening of the BM of the bladder epithelium was observed and remained almost constant from 4 to 20 weeks, although the pathological changes in the rat bladder epithelium induced by BBN altered over the same period of 20 weeks. The reason for this phenomenon can be explained by the increased interfacial area between the basal epithelial cells and the BM of the rat bladder epithelium due to an increase in the number and size of the microvilli on the basal cell surfaces adjacent to the BM. Our results also showed that the frequency of hemidesmosomes increased progressively during the period of carcinogenesis, especially in the lesions of noninvasive transitional cell carcinoma (TCC) in the rat bladder. It is suggested that the neosynthesis of BM components can be carried out both by benign hyperplastic cells and by noninvasive TCC cells of rat bladder. The alterations in the BM thickness may be affected by the changes in the number and size of the microvilli occurring on the basal cell surfaces adjacent to the BM. Both an increased frequency of hemidesmosomes and the neosynthesis of BM are closely related to cell proliferation during carcinogenesis.

Animals↗
PubMed1994

Role of cell-mediated immunity in bovine leukemia virus (BLV) infection in ruminants: its implication for the vaccination strategy against retroviruses.

Recent studies in the immunopathogenesis of bovine leukemia virus (BLV) infection in ruminants, reviewed herein, provide an insight into the vaccination strategy against retrovirus infection. It was shown that vaccination of naive sheep with a recombinant vaccinia virus (RVV) expressing BLV envelope glycoprotein protected the animals against BLV infection. The involvement of cell-mediated immunity (CMI) in this phenomenon was strongly suggested. The postinfection vaccination, that is, the vaccination of BLV-infected animals with RVV, also significantly suppressed BLV replication in the carrier animals. These findings support the idea that vaccination against retroviruses should put its emphasis on the induction of CMI and that such vaccine could be used not only for prophylactic but also for therapeutic purposes.

Animals↗
PubMed1992

Total synthesis of the modified ganglioside de-N-acetyl-GM3 and some analogs.

Methyl[methyl 4,7,8,9-tetra-O-acetyl-5-(tert-butoxycarbonylamino)-3,5- dideoxy-2-thio-D-glycero-alpha-D-galacto-2-nonulopyranosid]onat e was used for the glycosylation of benzyl O-(2,6-di-O-benzyl-beta-D-galactopyranosyl)- and benzyl O-(2,3-di-O-benzyl-beta-D-galactopyranosyl)-(1----4)-3,6-di-O-benzyl- 2-O-pivaloyl-beta-D-glucopyranoside to give benzyl O-[methyl 4,7,8,9-tetra-O-acetyl-5-(tert-butoxycarbonylamino)- 3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylonate]-(2-- --3)-O-(2,6-di-O-benzyl-beta-D-galactopyranosyl)-(21) and benzyl O-[methyl 4,7,8,9-tetra-O-acetyl-5-(tert-butoxycarbonylamino)-3,5- dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylonate]-(2----6) -O-(2,3-di- O-benzyl-beta-D-galactopyranosyl)-(1----4)-3,6-di-O-benzyl-2-O-pivaloyl- beta-D-glucopyranoside (18), respectively, accompanied by the beta-linked isomers 22 and 19, respectively. Compounds 18, 21, and 22 were converted into the corresponding glycotriosyl donors which, upon coupling with (2S,3R,4E)-3-O-benzoyl-2-N-tetracosanoylsphingenine, afforded completely protected ganglioside analogs 39, 40, and 41, respectively. Deprotection of 40, 41, and 39 completed the synthesis of the modified ganglioside de-N-acetyl-GM3, a stereoisomer, and a regioisomer. The N-deprotected forms of 40 and 39, on successive treatment with methyl isocyanate and O-deprotection, gave the N-(N-methylcarbamoyl) analogs of GM3 and its regioisomer.

Carbohydrate Sequence↗
PubMed1992

The acrolein cytotoxicity and cytoprotective action of alpha-tocopherol in primary cultured rat hepatocytes.

The influence of acrolein on hepatocytes and the effect of alpha-tocopherol on acrolein cytotoxicity were investigated using primary cultured rat hepatocytes. Hepatocellular injury was dependent on both acrolein concentration in medium and on duration of exposure. Treatment of hepatocytes with 100 microM acrolein resulted in a marked loss of cellular glutathione (GSH) within 15 min, gradual accumulation of cellular lipid peroxide (LPO) and subsequent lactate dehydrogenase (LDH) leakage in the medium from 3 hr after exposure to acrolein. Cellular GSH peroxidase (GSH-Px) activity at 2 hr was significantly decreased. Electron microscopic examination on hepatocytes at 8 hr revealed a marked swelling of mitochondria and ruptures of the plasma membrane. Simultaneous treatment with 100 microM acrolein and 20 microM alpha-tocopherol did not prevent the loss of cellular GSH, though it prevented the LPO accumulation and the LDH leakage. The decrease of cellular GSH-Px activity with acrolein treatment was not mitigated by co-treatment with alpha-tocopherol. Ultrastructural alterations of hepatocytes induced by acrolein were minimized by co-treatment with alpha-tocopherol. In conclusion, acute loss of GSH and GSH-Px may increase cellular LPO and lead to hepatocellular injury, though suppression of cellular LPO accumulation by alpha-tocopherol can prevent the hepatocellular injury, even under condition of lack of GSH and GSH-Px.

Acrolein↗
PubMed1992

Intrinsic radiosensitivity and PLD repair in osteosarcoma cell lines.

The response to radiation of seven osteosarcoma cell lines was analysed by in vitro colony-forming assay and compared with that of eight human fibroblast strains. The values of D0, the surviving fraction after 2 Gy (S2Gy), and the mean inactivation dose (D) of osteosarcoma cells in log-phase culture were significantly higher than those of fibroblast strains (p less than 0.01). PLD (potentially lethal damage) repair of osteosarcoma cells evaluated in the plateau phase of growth showed great variation for enhancement of survival, although all of the values were maximized within 12 h after irradiation. In the osteosarcoma, intrinsic radiosensitivity in vitro reflected the clinical response to radiation. However, the capacity for PLD repair might not be a good indicator for predicting the results of radiation therapy.

Cell Survival↗
PubMed1992

Augmentation of bovine leukemia virus (BLV)-specific lymphocyte proliferation responses in ruminants by inoculation with BLV env-recombinant vaccinia virus: their role in the suppression of BLV replication.

Lymphocyte proliferation responses were investigated in sheep and cattle, in which the replication of bovine leukemia virus (BLV) had been known to be suppressed by inoculation with recombinant vaccinia virus (rVV) expressing BLV envelope glycoprotein (gp60). Enhanced lymphocyte proliferation responses were observed in animals inoculated with rVV, regardless of whether they were naive or BLV carriers. These responses were roughly inversely correlated to the growth of BLV in the peripheral blood leukocytes. In contrast, there was no apparent correlation between humoral immune response and BLV growth. Based on these results, it was suggested that rVV rendered its suppressive effect of BLV replication primarily via augmentation of cell-mediated immunity.

Animals↗
PubMed1992

Improvement of simultaneous detection of antibodies to Gag and envelope antigens of human T-lymphotropic virus type I by western immunoblot assay.

To determine seropositivity for human T-lymphotropic virus type I (HTLV-I), we attempted to improve the detection system that uses antibody to HTLV-I Env in Western immunoblotting (WB) by adding an envelope glycoprotein (gp46) purified from the culture fluid of HTLV-I-producing cells by immunoaffinity chromatography and gel chromatography. In this WB, 177 of 179 serum samples showing seropositivity in an indirect immunofluorescence assay showed positive reactions to the gp46 envelope antigen as well as to p19, p24, and p53 Gag antigens. The remaining two samples showed negative reactions to p24. False-positive results were not found for 533 indirect immunofluorescence assay-negative serum samples, although one band to p19 or p24 was observed in 46 of the 533 samples. These 46 samples did not react to p53 and gp46, suggesting that these samples belonged to the indeterminate group in accordance with the criteria proposed by the World Health Organization. Therefore, this improved WB can be used for the confirmation of seropositivity.

Blotting, Western↗
PubMed1992

Pseudo-adrenal incidentaloma: magnetic resonance imaging in a patient with para-adrenal Castleman's disease.

We report a case of para-adrenal angiofollicular lymph node hyperplasia (Castleman's disease) of the hyaline-vascular type. The mass could not be differentiated from an adrenal tumor by ultrasonography and computed axial tomography (CT). However, magnetic resonance imaging (MRI) suggested the possibility of an extra-adrenal origin of the mass. The intensity of the mass by MRI was homogeneous and of a higher intensity in the T2-weighted image than in the T1-weighted image, a finding similar to lymphadenopathy, lymphatic tumorous mass or metastatic tumor of the lymph node. Ultrasonography, CT and MRI may not be useful in characterizing Castleman's disease, but MRI was useful to distinguish asymptomatic para-adrenal masses from those of adrenal origin.

Adrenal Gland Neoplasms↗