Search PubMed⌕ Search

Biomedical subjects

K Sudo

Publications and source records attributed to K Sudo.

At least 127 records · Page 7Linked to original sources
PubMed1995

[Progress in biotechnology and its clinical application to isozyme diagnosis].

Recent progress in biotechnology is tremendous and its application to isozyme diagnosis has been altered. First, the mechanism of isozyme system in molecular level has been revealed and clinical assessment of isozymes has been followed. Several examples are shown: tumor-producing amylase is caused by translocation of amylase gene; serum cholinesterase is encoded by only one gene; pyruvate kinase gene has two independent exon, containing translation initiator signal; electrophoretic variant of lactate dehydrogenase is caused by missense mutation; alkaline phosphatase isozymes are constituted from different allele products and post-translational modification. Second, improvement of assay procedure by using biotechnology have made isozyme analysis easier, faster, more convenient and more precise. Stable enzymes and monoclonal antibodies against the produced enzymes have been utilized for a different recognition of isozymes. It is believed that a diagnostic system of isozymes will be established in detail.

Biotechnology↗
PubMed1995

In vitro metabolism of nefiracetam by liver microsomes from rats, dogs and monkeys.

The in vitro metabolism of nefiracetam (CAS 77191-36-7, N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide, NEF, DM-9384), a novel cognition enhancer, has been investigated using liver microsomes from rats, dogs and monkeys. Microsomal metabolism of NEF showed qualitatively a similar profile in three species tested. Six metabolites were generated from incubation of NEF with liver microsomes. Their structures were identified using a thermospray LC/MS/MS (liquid chromatography/tandem mass spectrometry) method, as regioisomers of monhydroxylated derivatives of NEF: the 3-hydroxy (3-OH-NEF); 4-hydroxy (4-OH-NEF); 5-hydroxy (5-OH-NEF); 3'-hydroxy (3'-OH-NEF); 4'-hydroxy (4'-OH-NEF); hydroxymethyl (HM-NEF) metabolites. The heat lability, NADPH requirement and inhibition by prototype cytochrome P450 inhibitors (proadifen and metyrapone) implies that NEF oxidations are catalyzed by cytochromes P450. The major metabolic route was 5-OH-NEF formation in all species, corresponding well with the previous investigations in vivo. Inhibitory effects of alpha-naphthoflavone and quinidine on NEF hydroxylation suggest that several isoforms of cytochromes P450 are involved in the formation of these NEF metabolites.

Animals↗
PubMed1994

Ganglioside GD1 alpha in cerebellar Purkinje cells. Its specific absence in mouse mutants with Purkinje cell abnormality and altered immunoreactivity in response to conjunctive stimuli causing long-term desensitization.

The alpha-series ganglioside, IV3NeuAc,III6NeuAcGgOse4-Cer(GD1 alpha), was previously identified as a minor constituent in bovine brain gangliosides (Hirabayashi, Y., Hyogo, A., Nakao, T., Tsuchiya, K., Suzuki, Y., Matsumoto, M., Kon, K, and Ando, S. (1990) J. Biol. Chem. 265, 8144-8151). In the present study, we have generated a specific mouse monoclonal antibody against GD1 alpha and explored the distribution of GD1 alpha in murine central nervous system. In adult rat brain, GD1 alpha occurred as a minor constituent, and its expression was exclusively detected in the forebrain, the midbrain and the cerebellum. In the mouse cerebellum, the content of GD1 alpha was reduced significantly in the Purkinje cell-deficient mutants, lurcher (Lc/+), staggerer (sg/sg), and Purkinje cell degeneration (pcd/pcd), but were not reduced in the weaver (wv/wv) mutant, which loses mostly granule cells. The GD1 alpha synthase, assayed in cerebellar microsomes, was also reduced in Purkinje cell-deficient mutants. Immunohistochemistry showed that the staining for GD1 alpha in rat and mouse cerebella was mostly found in the proximal dendrites and cell bodies of Purkinje cells. Also, it appeared slightly in the processes of Bergmann glial cells. The immunoreactivity of GD1 alpha disappeared specifically from the Purkinje cell dendrites and the Bergmann glial processes after co-application of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and 8-bromo-guanosine 3':5'-cyclic monophosphate, which induced long-term desensitization of the AMPA-selective glutamate receptors in Purkinje cells. The present data provide suggestive evidence that GD1 alpha ganglioside is enriched in Purkinje cells and may have a role in Purkinje cell functions in the cerebellum.

Animals↗
PubMed1994

Suppression of cyclin D1 mRNA expression by the angiogenesis inhibitor TNP-470 (AGM-1470) in vascular endothelial cells.

The effects of TNP-470 on DNA synthesis and the expression of c-myc and cyclin D1 mRNAs were investigated in human umbilical vein endothelial (HUVE) cells synchronized by serum depletion and stimulated with bFGF and serum. DNA synthesis occurring 16 h after stimulation was inhibited when TNP-470 was present from 2 to 6 h after stimulation. C-myc mRNA expression occurring 2 h after stimulation was not inhibited by the addition of TNP-470. Cyclin D1 mRNA expression occurring 6 h after stimulation was suppressed in the presence of TNP-470 from 2 to 6 h after stimulation. On the other hand, cyclin D1 expression was not suppressed in the TNP-470-insensitive human tumor cell line WiDr. These results suggest that the inhibition of HUVE cells by TNP-470 is due to the suppression of cyclin D1 expression in mid G1 phase.

Antibiotics, Antineoplastic↗
PubMed1994

2058 expressed sequence tags (ESTs) from a human fetal lung cDNA library.

ESTs (expressed sequence tags) provide complementary resources for structural and functional analyses of the human genome. We have performed single-pass sequencing of 2058 randomly selected, directionally cloned cDNAs isolated from a fetal-lung cDNA library constructed with oligo(dT) primers. Computer analyses of the 5'-end sequences revealed that 60.4% of the clones were considered to be identical to previously reported human genes or ESTs; 9.0% of them showed significant homology to known genes in human, other mammals, or lower organisms; 30.6% showed no homology to any genes or DNA sequences in the public database. These data and reagents will be useful for future investigations of gene expression during prenatal development of human lung.

Amino Acid Sequence↗
PubMed1994

Angiogenic activity of the recombinant hst-1 protein.

The hst-1 transforming gene encodes a protein which belongs to the FGF family of growth factors. We showed previously that a human hst-1 protein produced in silkworm cells has in vitro mitogenic activity to vascular endothelial cells. Here we report effective synthesis of an unfused human hst-1 protein in E. coli and a potent in vivo angiogenic activity of this hst-1 protein by two in vivo assays for angiogenesis, chick chorioallantoic membrane assay and rat cornea assay. The NIH3T3 transformant transfected with the hst-1 gene appeared to develop a highly-vascularized tumor on nude mice. These data showed that the hst-1 protein has an angiogenic activity in vivo as well as in vitro.

Animals↗
PubMed1994

Heparin-binding epidermal growth factor-like growth factor is an autocrine growth factor for human keratinocytes.

Since heparin-binding epidermal growth factor (HB-EGF) is a member of the EGF family and binds to EGF receptor, we tested recombinant HB-EGF for its ability to stimulate human keratinocyte proliferation. The effect of HB-EGF on human keratinocytes was dependent on the cell density. HB-EGF optimally increased the cell number by 1.8-fold at 1.0 ng/ml for a 4-day incubation period under subconfluent culture. In contrast, under confluent culture, 10 ng/ml HB-EGF optimally increased the DNA synthesis 2.1-fold. To examine the production of HB-EGF by human keratinocytes, the analysis of human keratinocyte-conditioned medium was undertaken by a combination of heparin affinity column chromatography, EGF receptor-stimulating assay, immunoblotting, and neutralization. Heparin column chromatography fractionated three activities, peaks 1, 2, and 3, which contained immunoreactive 30- and 27-, 19-, and 14.5-kDa bands, respectively. The anti-HB-EGF-blocking antibody neutralized the activities of peaks 2 and 3 by 38 and 22%, respectively, but did not neutralize the activity of peak 1 at all. The antibody reduced the cell growth by 37% for a 4-day incubation period. Northern blot analysis detected a 2.5-kilobase transcript of HB-EGF. The addition of 1 ng/ml HB-EGF optimally increased the levels of HB-EGF mRNA 5.4-fold at 1 h and TGF-alpha mRNA 3.1-fold at 3 h. Interestingly, the addition of TGF-alpha at 1 ng/ml to keratinocyte cultures enhanced the level of HB-EGF mRNA 10.2-fold at 6 h. 1 ng/ml EGF also increased HB-EGF mRNA levels 10.9-fold at 1 h. These results suggest that HB-EGF is an autocrine growth factor for human keratinocytes, and HB-EGF and TGF-alpha act not only by an autoinductive mechanism but also by mutual amplification.

Cell Division↗
PubMed1994

Molecular cloning of a novel human cDNA homologous to CDC10 in Saccharomyces cerevisiae.

We isolated a novel human cDNA, termed hCDC10, whose predicted product showed a high degree of homology to the CDC10 protein of Saccharomyces cerevisiae. This cDNA contained an open reading frame of 1254 nucleotides encoding 418 amino acids, which included a GTP-binding motif, GX4GKS--DX2G--KXD. The predicted peptide sequence also revealed partial amino-acid identity (40-50%) with Diff 6 in Drosophila and with H5 in mouse. Each of these sequence homologues, including Saccharomyces cerevisiae CDC10, contains the GTP-binding motif. Northern blot analyses indicated that the hCDC10 gene is expressed ubiquitously in normal tissues.

Amino Acid Sequence↗
PubMed1994

Gomisin A, a lignan component of Schizandora fruits, inhibits development of preneoplastic lesions in rat liver by 3'-methyl-4-dimethylamino-azobenzene.

The effects of gomisin A, a lignan component of Schizandra fruits, on development of preneoplastic lesions in the liver after a short-term (3 weeks) feeding of 3'-methyl-4-dimethyl-aminoazobenzene (3'-MeDAB) to male Donryu rats were investigated, and compared with the effects of phenobarbital. Gomisin A inhibited both increases of the level of glutathione-S-transferase placental form (GST-P) and the number and size of GST-P positive foci in the liver increased after treatment with 3'-MeDAB. Moreover, although the population of diploid nuclei was increased and that of tetraploid nuclei was decreased by pretreatment with 3'-MeDAB, gomisin A returned this to near the normal ploidy pattern. But phenobarbital increased the level of GST-P and the number and size of GST-P positive foci with little affect on the ploidy population changed by 3'-MeDAB. Thus, the effect of gomisin A on hepatocarcinogenesis was inhibitory in contrast with that of phenobarbital. This study suggests that gomisin A is a candidate for a chemopreventive drug inhibiting the promotion process in hepatocarcinogenesis.

Animals↗
PubMed1994

Population screening of lactate dehydrogenase deficiencies in Fukuoka Prefecture in Japan and molecular characterization of three independent mutations in the lactate dehydrogenase-B(H) gene.

Screening for lactate dehydrogenase (LDH) subunit deficiencies was performed on 2880 blood samples from healthy individuals in the Fukuoka Prefecture in Japan by means of electrophoresis. The frequencies of heterozygotes with either LDH-A or LDH-B deficiency were found to be 0.104% at each locus. These estimated frequencies of either LDH-A or LDH-B deficiencies were slightly lower than, but not significantly different from, those found previously in Shizuoka Prefecture. The genetic mutations in individuals heterozygous for LDH-B deficiency were analyzed by the polymerase chain reaction and DNA conformation polymorphism. Abnormal migration patterns were observed in individuals heterozygous for LDH-B deficiency. Subsequent sequence determination of the mutant alleles revealed three novel mutations: an eight-base duplication in exon 3, a four-base duplication in exon 4, and a one-base deletion in exon 7 of the LDH-B gene. These three mutations result in frame-shift translation and premature termination. In addition, the mutations resulting in the duplication of eight or four nucleotides appear to cause a decrease in the levels of LDH-B mRNA.

Amino Acid Sequence↗
PubMed1994

A sensitive assay system screening antiviral compounds against herpes simplex virus type 1 and type 2.

A highly sensitive and accurate assay system was developed for in vitro evaluation of anti-herpes simplex virus (anti-HSV) agents using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and human embryonic lung fibroblast (MRC-5) cells. This assay system was found to be highly sensitive for both HSV-1 and -2. Confluent MRC-5 cells were infected with either HSV-1 KOS strain or HSV-2 G strain of 25 TCID50 in the presence of various concentrations of test compounds. The optical density of formazan was used to determine cell viability. The EC50 values of acyclovir and several other anti-HSV agents were found to be similar to those obtained by the plaque reduction method. These results indicate that this MTT assay is useful for screening anti-HSV-1 and -2 agents.

Acyclovir↗
PubMed1994

Cytostatic inhibition of endothelial cell growth by the angiogenesis inhibitor TNP-470 (AGM-1470).

Recently, we reported the anti-angiogenic action along with anti-tumour activity of TNP-470 (AGM-1470). In this study, the effect of TNP-470 on the growth of human umbilical vein endothelial (HUVE) cells was examined. TNP-470 inhibited the growth of HUVE cells in a biphasic manner. The inhibition was cytostatic in the first phase (complete inhibition at 300 pg ml-1 to 3 micrograms ml-1 with an IC50 of 15 pg ml-1) and cytotoxic in the second phase (> or = 30 micrograms ml-1). The cytostatic inhibition of HUVE cell growth by TNP-470 was durable after washing out TNP-470 in culture. Incorporation of thymidine but not uridine and leucine by HUVE cells was inhibited in the first phase, while that of all three compounds was inhibited in the second phase. Human and rat endothelial cells among various types of cells were the most sensitive to the cytostatic inhibition, while differences in the cytotoxic inhibition were minimal. These results suggest that TNP-470 exerts its specific anti-angiogenic action by inhibiting cytostatically growth of endothelial cells in a relatively specific manner.

Antibiotics, Antineoplastic↗
PubMed1994

Drug absorption from large intestine: physicochemical factors governing drug absorption.

Profiles of absorption versus drug molecular weight and absorption versus drug lipophilicity were investigated in both the small and large intestines of rats by an in situ loop method. The absorption-molecular weight profiles examined using different-sized polyethylene glycols (PEGs) were different between the small and large intestines; the large-intestinal absorption of PEGs with molecular weights larger than 300 was poor, while PEGs with molecular weights up to 600 were relatively well absorbed in the small intestine. It is suggested that the paracellular route for drug penetration in the large intestine is restricted more than in the small intestine. The absorption-lipophilicity profiles were also examined in various regions (loops of 6 cm) of rat intestine using three acylsalicylic acids, acetyl-, propionyl- and butyrylsalicylic acids. The absorption rates of the acylsalicylic acids were different in the intestinal regions: the jejunum > the ileum > the colon > the rectum. In each region, the absorption rate increased with the drug lipophilicity. However, it was shown that the absorption rates in the small intestine tended to reach a ceiling at the high lipophilicity. To confirm this tendency, the absorption rates of acetaminophen and indomethacin were compared in the four intestinal regions. The absorption rates of highly lipophilic indomethacin were similar in the large and small intestines, while intermediately lipophilic acetaminophen was more rapidly absorbed in the small intestine than in the large intestine. A thicker unstirred water layer adjacent to the small-intestinal mucosa would be one of the factors which cause such varying absorption-lipophilicity profiles.

Animals↗
PubMed1994

Fast-type electrophoretic variant of lactate dehydrogenase M(A) and comparison with other missense mutations in lactate dehydrogenase M(A) and H(B) genes.

An electrophoretic variant of lactate dehydrogenase (LD) M(A) subunit was discovered in a female patient with chest pain. Her LD activity in serum was within the normal reference interval, and analysis of her LD isoenzyme pattern showed an abnormal migration indicating a fast-type LD-M(A) subunit variant. DNA analysis of the mutant LD-M gene detected a single base substitution, an A to G transition at codon 220 (AAA-->GAA). This mutation resulted in the replacement of a lysine by a glutamic acid (mutation K220E) and produced a subunit variant (electrophoretic fast type). This missense mutation was also observed in the patient's son, and genotypes of mother and son were consistent with their biochemical phenotypes, as evaluated by LD isoenzyme analysis.

Base Sequence↗
PubMed1994

[Surgical management of coronary artery fistula with tricuspid stenosis in a three-month-old infant].

This is a case report of a 3-month-old infant who had been suffering from progression of cardiac failure. Two dimensional echo-cardiography revealed a fistula between the right coronary artery to the right heart. He was operated upon using extracorporeal circulation. Symbas procedure was carried out to close the fistula. Upon opening the right atrium, there noted tricuspid stenosis (TS). Then, ASD was created to reduce the right atrial pressure to prevent right heart failure secondary to TS. He is doing well postoperatively.

Arteriovenous Fistula↗