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Biomedical subjects

M Isemura

Publications and source records attributed to M Isemura.

At least 19 recordsLinked to original sources
PubMed1992

Increased expression of the 67kDa-laminin receptor gene in human small cell lung cancer.

Gene expression of the precursor of the 67kDa-laminin receptor was examined by Northern analysis using 11 established human lung cancer cell lines and 25 lung cancer tissues obtained by operation. As a result, one transcript, the size of which was 1.2 kb was shown in all cell lines and tissues examined. An increased level of mRNA was demonstrated in cell lines which proliferated rapidly and in small cell lung cancer cell lines. It was also indicated that gene expression of the laminin receptor was up-regulated especially in small cell lung cancer tissue. In this context, 67kDa-laminin receptor appears to be a marker for biological aggressiveness of human lung cancer.

Adenocarcinoma↗
PubMed1991

The usefulness of simultaneous determinations of glucosaminylation and fucosylation indices of alpha-fetoprotein in the differential diagnosis of neoplastic diseases of the liver.

The degrees of glucosaminylation (glucosaminylation index) and fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples of 351 patients with hepatocellular carcinoma (HCC), 47 with carcinoma metastatic to the liver from digestive organs, five with mixed cholangiocellular and HCC, and 176 with benign liver diseases. The glucosaminylation index of AFP in patients with carcinoma metastatic to the liver (42 +/- 23%, mean +/- SD) was significantly higher than that in patients with HCC (5 +/- 7%, P less than 0.001) or that in patients with benign liver diseases (2 +/- 4%, P less than 0.001). The fucosylation indices of AFP in patients with carcinoma metastatic to the liver, with HCC, and with benign liver diseases were 76 +/- 25%, 42 +/- 30%, and 4 +/- 6%, respectively. Thus, the fucosylation indices of AFP were high in two neoplastic liver diseases (carcinoma metastatic to the liver and HCC) and low in benign liver diseases, whereas the glucosaminylation indices were high in carcinoma metastatic to the liver but low in HCC and benign liver diseases. When the values of 30% and 80% were used as the level of the glucosaminylation and fucosylation indices, respectively, to discriminate carcinoma metastatic to the liver from HCC, 40 of 47 patients with carcinoma metastatic to the liver (85%) were able to be discriminated from HCC (sensitivity). The specificity, the positive predictive value, and the overall accuracy were 86% (302/351), 45% (40/40 + 47 + 3 - 2) and 86% (40 + 302/47 + 351), respectively. These data suggest that the combined information in these two indices provides a potent criterion for the diagnosis of neoplastic diseases of the liver.

Adenoma, Bile Duct↗
PubMed1991

Changes in hepatic metabolism through simulated weightlessness: decrease of glycogen and increase of lipids following prolonged immobilization in the rat.

The effect of simulated weightlessness on hepatic metabolisms of carbohydrates and lipids was investigated in rats that were chronically immobilized by means of a suspension harness. During the 10-day period of the suspension, the animals showed a substantial decrease in the hepatic glycogen content, whereas the content of hepatic total lipids was markedly elevated. Similar results were obtained when the "suspended" animals were provided with a regular amount of nutrients by a force-feeding procedure. In the suspended animals, hepatic parenchymal cells were filled with large fat droplets, and hepatic triglyceride contents were elevated. The prolonged immobilization led to a slight, but significant, increase in glucose-6-phosphatase activity in the liver, suggesting that an increased glycogen breakdown might have occurred in the suspended animals. However, it was unlikely that the increased amount of glucose produced by the glycogen breakdown was utilized as a substrate for the lipogenesis in the liver, because hepatic lipogenic enzyme activities were unaffected by the suspension. The results suggest that the hepatic lipids accumulate in animals exposed to a prolonged immobilization state, presumably due to a decreased lipolysis and/or a suppressed lipoprotein mobilization from the liver into the blood stream.

Adrenal Glands↗
PubMed1991

Fractionation of jelly substance of the sea urchin egg and biological activities to induce acrosome reaction and agglutination of spermatozoa.

Jelly coat substance surrounding the egg of the sea urchin, Hemicentrotus pulcherrimus, was fractionated by gel filtration and three fractions designated A, B, and C were obtained which mainly consisted of fucose sulfate, sialic acid, and protein, respectively. The biological activities of the fractions were examined for induction of acrosome reaction (AR) and agglutination of spermatozoa. Only fraction A, a fucose-rich glycoprotein fraction, had activities for both AR and agglutination. Fraction A was found to lose activity for AR but to retain activity for agglutination after pronase digestion. Pronase-digested fraction A was further fractionated by the same gel filtration and three fractions designated P1, P2, and P3 were obtained, which contained mainly fucose sulfate, sialic acid, and proteinous material, respectively. These fractions had no activity for AR but activity for agglutination resided in fraction P1, a fucose sulfate fraction. Furthermore, beta-elimination of the jelly substance was carried out to separate protein and fucose sulfate polysaccharide and three fractions designated E1, E2, and E3 were obtained by gel filtration, of which the fucose-rich fraction (E1) exhibited activities for both AR and agglutination, and the sialoprotein fraction (E2) retained activity only for AR. However, the activity for AR of both fractions was destroyed by pronase digestion. These results suggest that activity to induce AR resides in the protein moiety of fucose-rich glycoprotein and activity for agglutination resides in the fucose sulfate polysaccharide moiety of the same glycoprotein of the jelly substance.

Acrosome↗
PubMed1991

Myosin light chain kinase inhibitors ML-7 and ML-9 inhibit mouse lung carcinoma cell attachment to the fibronectin substratum.

We studied the effects of various protein kinase inhibitors on the attachment of mouse lung carcinoma 3LL cells to the fibronectin (FN) substratum. Calmodulin antagonists (W-7 and W-13) and myosin light chain kinase inhibitors (ML-7 and ML-9) exhibited the inhibitory effect for the attachment, while inhibitors of protein kinases A and C were ineffective. Since Arg-Gly-Asp-containing hexapeptide blocked the attachment, cell surface FN receptor appeared to be involved in this mechanism. These results support the hypothesis that the cell attachment requires the rearrangement of the cytoskeleton in association with the phosphorylation of myosin light chain which would lead to the clustering of the cell surface FN receptors.

Animals↗
PubMed1991

Immunohistochemical alterations in basement membrane components of squamous cell carcinoma.

To investigate alterations in the basement membrane (BM) in squamous cell carcinoma (SCC), we investigated 20 tumors. Four had the cytologic characteristics of Bowen's disease (SCC-BD) and 16 did not have them (SCC-NB). Tumors were studied immunohistochemically by double immunofluorescent staining by using mouse monoclonal antibodies to the core protein of heparan sulfate proteoglycan (HSPG) and chondroitin 6-sulfate glycosaminoglycan (Ch6S) as well as rabbit antiserum to laminin (LN) and type IV collagen (C-4). In well-differentiated and highly keratinized SCC-NB, LN, C-4, and HSPG could be detected in the tumor nest BM and showed no loss of continuity, but they were largely lost in poorly differentiated and poorly keratinized SCC-NB. This suggests that poorly differentiated SCC-NB cause greater enzymatic degradation of BM components than well-differentiated SCC-NB. Ch6S was detected in parts of the BM of SCC-BD, but it was absent in all SCC-NB examined. It appears that SCC-NB have lost the ability to synthesize Ch6S, and that SCC-BD degrade Ch6S although they continue to produce it. Thus, it appears that in SCC the BM is qualitatively different from that of normal epidermis, and that SCC-BD can be distinguished from SCC-NB by the Ch6S content of the BM.

Antibodies↗
PubMed1990

A lectin-based monoclonal enzyme immunoassay to distinguish fucosylated and non-fucosylated alpha-fetoprotein molecular variants.

Purified alpha-fetoprotein (AFP), fucosylated AFP mixtures, and 40 sera from patients with AFP-producing hepatocellular carcinoma were analysed by monoclonal enzyme immunoassay (EIA) to distinguish fucosylated and nonfucosylated AFP molecular variants. FUC-AFP-25 was discriminated from FUC-AFP-75 by the EIA using monoclonal antibody 18H4 in the range of total AFP concentrations from 100 to 800 ng/mL. In addition, sera from 40 patients with hepatocellular carcinoma, with AFP concentrations from 100 to 1270 ng/mL and with fucosylated AFP from 0 to 100% by conventional cross immuno-affinoelectrophoresis, were also analysed by the present EIA. A statistically significant correlation was obtained between the data from the present EIA and from the conventional crossed immuno-affinoelectrophoresis in the range of fucosylated AFP more than 20% and the serum concentration of AFP more than 100 ng/mL. These results indicate that the present EIA is useful for clinical detection of hepatocellular carcinoma during the follow-up of patients with chronic liver diseases.

Antibodies, Monoclonal↗
PubMed1989

Alterations in the extracellular matrix components in human glomerular diseases.

We investigated the distribution of extracellular matrix components such as fibronectin, laminin, type III, IV, V, and VI collagens and heparan sulfate proteoglycan (HSPG) in normal and diseased glomeruli using the indirect immunofluorescence method. This study included 96 renal biopsies: 7 controls, 3 minimal change nephrotic syndrome (MCNS), 47 mesangial proliferative glomerulonephritis (PGN), 25 membranous nephropathy (MN) and 14 membranoproliferative glomerulonephritis (MPGN) including 3 lupus nephritis. Fibronectin was detected predominantly in the mesangium and less prominently in the glomerular basement membrane (GBM) of normal glomeruli. Laminin and type IV collagen were present in the mesangium and GBM, type III collagen in the interstitium, and type V collagen in the mesangium, interstitium and a part of GBM. Type VI collagen was observed in the mesangium, interstitium and slightly in GBM. Anti-HSPG antibody reacted with the mesangium and GBM. MCNS showed a distribution of these antigens similar to that in normal controls. The finding that staining for HSPG was not decreased in the GBM and mesangium indicated that there was no change in the core protein of HSPG. Fibronectin, laminin, type IV collagen and HSPG were increased in the thickened GBM of MN and in the expanded mesangium of PGN. In MPGN, these matrix components were increased in the mesangium and GBM with remarkable increase of type V and VI collagens. While type III collagen was not found in normal glomeruli, it became detectable in the mesangium and a part of GBM in MPGN. No significant decrease in the intensity of fluorescence for HSPG was observed in the glomeruli from nephrotic patients. These findings suggest that proteinuria might be caused by the structural alteration in the glycosaminoglycan portion of HSPG, changes in any anionic material other than HSPG, or both, and also indicate that the glomerular mesangial sclerosis is closely related to the increase of type V and VI collagens.

Basement Membrane↗
PubMed1989

Structures of asparagine-linked oligosaccharides of human placental fibronectin.

The asparagine-linked sugar chains of fibronectin purified from human placenta were quantitatively released as oligosaccharides by hydrazinolysis. After N-acetylation, they were converted to radioactive oligosaccharides by NaB3H4 reduction. The radioactive oligosaccharides were fractionated by their charge on an anion-exchange column chromatography. All of the acidic oligosaccharides could be converted to neutral oligosaccharides by sialidase digestion. These oligosaccharides were then fractionated by serial affinity chromatography using immobilized lectin columns. Study of each oligosaccharide by sequential exoglycosidase digestion and methylation analysis revealed the following information as to the structures of the sugar chains of human placental fibronectin: 1) nine sugar chains are included in one molecule; 2) all sialic acid residues are exclusively linked at the C-3 position of the galactose residues; 3) bi-, tri-, and tetraantennary complex-type oligosaccharides with the Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4 (+/- Fuc alpha 1----6)-GlcNac as their cores were found; 4) the bisecting N-acetylglucosamine residue and the Gal beta 1----4GlcNAc beta 1----repeating groups are included in some of the sugar chains.

Asparagine↗
PubMed1989

Detection of bisected biantennary form in the asparagine-linked oligosaccharides of fibronectin isolated from human term amniotic fluid.

Fibronectin purified from human term amniotic fluid contains 10 asparagine-linked sugar chains in one molecule. The sugar chains were quantitatively liberated as radioactive oligosaccharides from the polypeptide moiety by hydrazinolysis followed by N-acetylation and NaB3H4 reduction and fractionated by anion-exchange column chromatography and serial lectin affinity chromatography. The structures of these sugar chains were determined by sequential exoglycosidase digestion in combination with methylation analysis. The results indicated that they are a mixture of bisected and non-bisected bi- and triantennary complex-type sugar chains with and without a fucose on the proximal N-acetylglucosamine residue and with Gal beta 1----4GlcNAc beta 1----, GlcNAc beta 1----, Neu5Ac alpha 2----3Gal beta 1----4GlcNAc beta 1----, and Neu5Ac alpha 2----6Gal beta 1----4GlcNAc beta 1---- groups in their outer chain moieties.

Amniotic Fluid↗
PubMed1989

Collagen-binding affinity of beta-2-microglobulin, a preprotein of hemodialysis-associated amyloidosis.

beta 2-Microglobulin (B2M) is the amyloid preprotein that accumulates in amyloid osteoarthropathy associated with hemodialysis. To elucidate the mechanism of such amyloidogenesis, we investigated the interaction between B2M and collagen in vitro by solid-phase enzyme immunoassay. Soluble collagens which had been solidified on plastic plates were allowed to react sequentially with B2M, peroxidase-conjugated antibody to B2M, and the substrate. The collagen-binding activity was dependent on the concentration of B2M and collagen, respectively. These results suggest that the collagen-binding affinity of B2M plays an important role in amyloidogenesis.

Amyloidosis↗
PubMed1988

The fucosylation index of alpha-fetoprotein and its usefulness in the early diagnosis of hepatocellular carcinoma.

The serum concentration and degree of fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples from 258 patients with hepatocellular carcinoma (HCC) and 114 patients with benign liver diseases. When the serum AFP concentration was below 1000 ng/ml, it could not be used as a measure to distinguish between HCC and benign liver diseases. However, the fucosylation index of AFP proved useful for such a purpose. The sensitivity of the analysis using the fucosylation index in total patients with HCC was 69%; the specificity was 96% in benign liver diseases, and the accuracy of this test was 77%. When HCC patients who were grouped according to tumor size (5 cm, 3 cm, and 2 cm in diameter) were analyzed, they all had a fucosylation index significantly higher than that in benign liver disease patients. The mean fucosylation index in 28 patients with a serum AFP concentration below 1000 ng/ml and a tumor diameter less than 3 cm was 26 +/- 30%. Corresponding values for 16 patients with an AFP concentration below 400 ng/ml and a tumor size less than 3 cm and for 8 patients with a concentration below 400 ng/ml and a tumor size less than 2 cm were 32 +/- 31% and 27 +/- 27%, respectively. These values were higher, with statistical significance, than those in patients with benign liver diseases. These data indicate that the measurement of the fucosylation index of AFP is useful for the early diagnosis of HCC.

Biomarkers, Tumor↗
PubMed1987

Isolation and characterization of fibronectin-binding proteoglycan carrying both heparan sulfate and dermatan sulfate chains from human placenta.

A proteoglycan was isolated from the human placenta by procedures including affinity chromatography with fibronectin immobilized on agarose. The glycosaminoglycan chains were found to be composed of heparan sulfate (86%) and dermatan sulfate (14%). The average molecular weights were estimated to be 1.8 X 10(5) for heparan sulfate and 1.2 X 10(5) for dermatan sulfate. Mouse monoclonal antibodies HS42 and HS47 were prepared against the proteoglycan, and examination of the specificity of these antibodies indicated that they recognized the core protein portion. The binding specificity, as studied by the solid phase enzyme-linked immunoassay with monoclonal antibody HS47, indicated that the proteoglycan bound to solid phase fibronectin and to laminin, but not to collagen types I, II, and IV or gelatin. Competitive immunoassays suggested that the proteoglycan bound weakly to the liquid phase-soluble fibronectin. These studies also indicated that the core protein was involved in the interaction between the proteoglycan and solid phase fibronectin. The ubiquitous distribution of this proteoglycan in the human tissues was demonstrated by the immunohistochemical method and thus suggested its important role in the tissue organization and function.

Amino Acids↗
PubMed1987

Close topographical relationship in alpha foetoprotein (AFP) between a lens culinaris binding glycan and the epitope recognized by AFP-reactive monoclonal antibody, 18H4.

Monoclonal antibodies 18H4 and 19F12 against alpha-foetoprotein (AFP) were examined by enzyme immunoassay for binding to two forms of AFP that were separated on the basis of the reactivity with lentil lectin (LCA). LCA-binding and LCA non-binding AFP, coated on a solid phase, reacted with 18H4 but reactivity with the LCA-binding species was inhibited by 60% following pretreatment of the AFP with LCA. The lectin was a very poor inhibitor of binding of 18H4 to the AFP which did not interact with LCA. In an alternative binding assay, a polyclonal anti-AFP coated solid phase was reacted with beta-galactosidase-labelled 18H4. Pre-treatment with LCA of the LCA-reactive AFP gave 56% inhibition of binding of conjugated 18H4 while little inhibition was achieved with the LCA-nonreactive AFP component. These findings show that the epitope recognised by 18H4 is distinct from the glycan sequence that is reactive with LCA. However, the LCA-binding oligosaccharides occur in close proximity to the 18H4 epitope in the native AFP.

Antibodies, Monoclonal↗
PubMed1987

Effects of extracellular matrices on human keratinocyte adhesion and growth and on its secretion and deposition of fibronectin in culture.

Extracellular matrices (ECMs) play an important role as components of basement membrane of normal human skin and in migrating epidermal cells in wound healing. We investigated the effects of various ECMs on human keratinocyte adhesion and growth as well as on its secretion and deposition of fibronectin (FN) in vitro using a serum-free, low-calcium culture system. Since cell adhesion is the first step of cell growth, we performed cell adhesion assay for 14 h. Human keratinocytes adhered best on FN and less well on types I/III collagen, type IV collagen, and heparan sulfate proteoglycan (HSPG) as compared with bovine serum albumin (BSA) (control) or laminin (La). Cell growth assayed for 7-8 days on the dishes coated with various extracellular matrices revealed significantly increased keratinocyte growth on FN and on types I/III collagen in comparison with that on type IV collagen, HSPG, BSA (control), or La. Morphology of keratinocytes and of their colonies on FN and types I/III collagen was strikingly different from that of the control; the colonies were not so compact as in the control, but rather loose and larger; each keratinocyte was spread out more on these substrata. These morphologic features seemed to correlate with the increased keratinocyte growth on these extracellular matrices. Both immunofluorescence study for FN with keratinocytes in 8-day culture on various extracellular matrices and enzyme-linked immunosorbent assay for FN measurement on substratum or in conditioned medium with keratinocytes in 5-day culture demonstrated that extracellular matrices modulated the secretion and deposition of FN by human keratinocytes in culture; the keratinocyte growth correlated with the amount of FN detected on substratum but not with that in medium. Based on the results of the present investigation, we think that the growth of human keratinocytes depends on the amount of FN on substratum.

Cell Adhesion↗
PubMed1986

Isolation and characterization of chondroitin sulfate proteoglycans from porcine thoracic aorta.

A chondroitin sulfate proteoglycan fraction was prepared from the 3 M MgCl2 extract of porcine aortas by DEAE-cellulose chromatography, followed by gel filtration through Sepharose CL-4B. Affinity chromatography of the fraction with antithrombin III-agarose yielded two chondroitin sulfate proteoglycans of a non-binding (proteoglycan IA) and binding (proteoglycan IB) nature. Proteoglycans IA and IB were different from each other in molecular size, in proportion of the protein relative to the polysaccharide portion, and in size of the chondroitin sulfate chain. They were also distinguished immunochemically. These data indicate that the intima-media of the aorta contains at least two distinct species of chondroitin sulfate proteoglycan.

Amino Acids↗