Search PubMed⌕ Search

Biomedical subjects

S Tsuji

Publications and source records attributed to S Tsuji.

At least 451 records · Page 25Linked to original sources
PubMed1996

Molecular cloning and expression of a third type of rabbit GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase.

Recent molecular investigation revealed that two closely related structural genes encode distinct GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferases (alpha1,2-fucosyltransferases). Some human cancer cells or tissues may express an aberrant alpha1, 2-fucosyltransferase other than H- and Secretor-type alpha1, 2-fucosyltransferase. However, definite evidence of the existence of a third type of alpha1,2-fucosyltransferase has not been demonstrated. Here we report the molecular cloning of a third type of rabbit alpha1,2-fucosyltransferase (RFT-III) from a rabbit genomic DNA library. The DNA sequence included an open reading frame coding for 347 amino acids, and the deduced amino acid sequence of RFT-III showed 59 and 80% identity with those of the previously reported two types of rabbit alpha1,2-fucosyltransferase, RFT-I and RFT-II, respectively. COS-7 cells transfected with the RFT-III gene exhibited alpha1,2-fucosyltransferase activity toward phenyl-beta-Gal as a substrate. Neuro2a (a murine neuroblastoma cell line) cells transfected with the RFT-III gene expressed fucosyl GM1 (type 3 H) but not Ulex europaeus agglutinin-1 lectin reactive antigens (type 2 H). Kinetic studies revealed that RFT-III exhibits higher affinity to types 1 (Galbeta1, 3GlcNAc) and 3 (Galbeta1, 3GalNAc) than to type 2 (Galbeta1, 4GlcNAc) oligosaccharides, which suggests that RFT-III as well as RFT-II is a Secretor-type alpha1, 2-fucosyltransferase. RFT-III was expressed in the adult gastrointestinal tract. The RFT-I, -II, and -III genes were assigned within 90 kilobases on pulsed field gel electrophoresis analysis. These results constitute direct evidence that, at least in one mammalian species, three active alpha1,2-fucosyltransferases exist.

Amino Acid Sequence↗
PubMed1996

Instability of mutant Cu/Zn superoxide dismutase (Ala4Thr) associated with familial amyotrophic lateral sclerosis.

In about 20-25% of cases of familial amyotrophic lateral sclerosis (FALS) patients have mutations in the Cu/Zn superoxide dismutase (SOD1) gene. The mechanism through which the mutations in the SOD1 gene cause ALS still remain unknown. We performed pulse-chase experiments using a system for the transient expression of human SOD1 in COS7 cells to examine whether the Ala4Thr mutation, which we previously reported, decreases the stability of SOD1. The expression vector (pEF-BOS) carrying the wild-type or mutant (Ala4Thr) human SOD1 cDNA was transfected into COS7 cells, and transiently expressed human SOD1 was then metabolically radiolabeled. Half-lives of the wild-type and the Ala4Thr mutant SOD1 were determined to be 78 h and 18 h, respectively. These results suggest that the Ala4Thr mutation in SOD1 decreases the stability of SOD1 and that this instability may play an important role in the pathogenesis of the degeneration of motor neurons in FALS.

Amyotrophic Lateral Sclerosis↗
PubMed1996

Molecular cloning and genomic analysis of mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase.

cDNA and genomic clones encoding mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase (ST6GalNAc II) were isolated, and the structure organization of the gene was determined. The predicted amino acid sequence is 57.4% identical to the chick ST6GalNAc II sequence but 33.8% identical to the chick ST6GalNA I (GalNAc alpha2, 6-sialyltransferase) sequence. The ST6GalNAc II gene is constitutively expressed in various mouse tissues but highly expressed in lactating mammary gland and adult testis. The gene contains nine exons spanning about 25 kilobases of genomic DNA and encodes a messenger RNA of 1995 nucleotides. Primer extension and S1 nuclease protection analysis of submaxillary gland mRNA showed that the transcription of the ST6GalNAc II gene starts from 68 nucleotides upstream from the translation start site. Characterization of 5'-flanking genomic regions indicated that the Galbeta1,3GalNAc-specific GalNAc alpha2,6-sialyltransferase promoter is embedded in a G+C-rich domain and contains no TATA or CAAT box but has putative binding sites for transcription factors Sp1 and AP-2. Transient transfection experiments involving luciferase reporter genes demonstrated promoter activity in NIH3T3 cells.

3T3 Cells↗
PubMed1996

Lack of association between dopamine D2 receptor gene Cys311 variant and schizophrenia.

Itokawa et al. [1993] reported identifying one missense nucleotide mutation from C to G resulting in a substitution of serine with cysteine at codon 311 in the third intracellular loop of the dopamine D2 receptor in schizophrenics. Arinami et al. [1994] reported finding a positive association between the Cys311 variant and schizophrenia. In response to the report by Arinami et al. [1994] we examined 106 unrelated Japanese schizophrenics and 106 normal controls to determine if there is any association of the Cys311 variant with schizophrenia. However, we found no statistically significant differences in allelic frequencies of Cys311 between schizophrenia and normal controls. The present results as well as those of all previous studies except for that of Arinami et al. [1994] indicated that an association between the dopamine D2 receptor gene and schizophrenia is unlikely to exist.

Adolescent↗
PubMed1996

Patterns of growth inhibitory factor (GIF) and glial fibrillary acidic protein relative level changes differ following left middle cerebral artery occlusion in rats.

Growth inhibitory factor (GIF) has been identified as a new metallothionein-like protein, the level of which is decreased in the Alzheimer's disease brain. GIF and glial fibrillary acidic protein (GFAP) have been reported to be expressed in reactive astrocytes in the rat brain following stab wounds. Moreover, strong expression of GIF mRNA in reactive astrocytes after ventricular injection of kainic acid has been demonstrated. To clarify the biological functions of GIF and GFAP in repair of the CNS, we examined changes in their relative levels to sham control using a Western blotting technique in the rat left hemisphere following occlusion of the left middle cerebral artery, for 28 days after surgery. The GIF relative level declined to 56% of the sham-operated control value on day 7. Thereafter the GIF relative level increased and returned to the normal relative level by days 21-28. The GFAP relative level increased from day 3 and reached a maximum of 120% of the sham-operated control value on days 14-21. While GIF and GFAP were both detected in reactive astrocytes, an increase in the GFAP relative level occurred prior to an increase in GIF relative level following the ischemia. The patterns of changes in relative expression levels of GIF and GFAP were quite similar to those in our previous studies on effects of cerebral stab wounds in rats, although the changes were more rapid in the previous studies. GIF and GFAP appear to play different roles in the repair of the CNS. The present results also indicated that GIF could play an important role in CNS repair after cerebral ischemia and provide new insights into the mechanism of gliosis investigated mainly from the viewpoint of GFAP.

Animals↗
PubMed1996

The F(ab')2 fragment of an anti-ICAM-1 monoclonal antibody attenuates liver injury after orthotopic liver transplantation.

Long-term storage of liver grafts results in increased adhesion of leukocytes onto the sinusoidal walls. This eventually leads to posttransplant graft damage through disturbances of hepatic microcirculation. Intracellular adhesion molecule-1 (ICAM-1) is known to be involved in attachment of leukocytes. This study was designed to examine whether ICAM-1 participated in the pathogenesis of posttransplant liver injury. Inbred Lewis rats were used as both donors and recipients to avoid immunoreactivity. Donor livers were stored for either 1 or 6 hr in ice-cold Euro-Collins solution and subsequently implanted. Expression of ICAM-1 was examined immunohistochemically. In some rats that received livers stored for 6 hr, the intact IgG (1.0 mg/kg) or the F(ab')2 fragment (0.5 mg/kg) of an anti-ICAM-1 mAb (1A29) was administered via the tail vein immediately after reperfusion of portal blood. In the group receiving livers stored for 6 hr, ICAM-1 began to be expressed on the sinusoidal endothelial cells as early as 15 min after reperfusion of the portal blood. Strong ICAM-1 expression was observed from 2 hr up to 24 hr after reperfusion. In contrast, expression of ICAM-1 was not evident at any time point after surgery in the 1-hr storage group as well as in untransplanted, normal livers. Serum alanine aminotransferase (ALT) levels were significantly higher in the 6-hr storage group compared with those of the 1-hr storage group (1-hr: 171 +/- 9 IU/L; 6-hr: 825 +/- 109 IU/L, P < 0.05; mean +/- SEM) 24 hr after transplantation. Serum ALT levels were markedly reduced by treatment with the F(ab')2 fragment of 1A29 (247 +/- 34 IU/L, P < 0.05 vs. 6-hr storage group). This was associated with reduced accumulation of leukocytes in the liver. In marked contrast, treatment with the intact IgG of 1A29 increased serum ALT levels dramatically (5297 +/- 634 IU/L, P < 0.05 vs. 6-hr storage group) and reduced serum complement. Histological examination revealed focal hepatocellular necrosis 24 hr after surgery in the 6-hr storage group. Treatment with the F(ab')2 fragment decreased the liver damage; in marked contrast, treatment with the intact IgG strikingly aggravated the injury, as characterized by massive necrosis throughout the liver. Liver damage caused by the intact IgG might be related to activation of the complement system by the Fc portion of the antibody. Taken together, these results indicate that ICAM-1 is involved in the mechanism of postoperative liver injury following liver transplantation.

Animals↗
PubMed1996

X-linked nonprogressive congenital cerebellar hypoplasia: clinical description and mapping to chromosome Xq.

We examined a large family in which an X-linked recessive congenital ataxia manifested in 7 males from three generations. The affected boys first exhibited a marked delay of early developmental motor milestones. A neurological syndrome became evident by 5 to 7 years of age and included cerebellar ataxia, dysarthria, and external ophthalmoplegia; there were no symptoms of mental retardation, spastic paraparesis, or sensory loss. Neuroimaging studies revealed hypoplasia of cerebellar hemispheres and vermis. The disease showed no progression beyond early childhood. The unique heredity and clinical features clearly distinguish this new entity from a variety of previously described familial ataxias. Pairwise linkage analysis and haplotype reconstruction allowed us to map the gene responsible for this disorder to a 38-cM interval on chromosome Xp11.21-q24 flanked by the loci DXS991 and DXS1001. Upon multipoint linkage analysis, the disease gene was determined to be located most likely in the proximal part of chromosome Xq, with the maximal lod score of 4.66 at the locus DXS1059 (Xq23). This is the first example of the genetic mapping of a pure congenital cerebellar hypoplasia syndrome.

Adolescent↗
PubMed1996

Lack of association of very low density lipoprotein receptor gene polymorphism with Caucasian Alzheimer's disease.

To determine whether the association of the very low density lipoprotein receptor (VLDL-R) gene with Alzheimer's disease (AD), which has recently been identified in Japanese AD patients, is commonly observed in AD patients of other ethnic backgrounds, we have investigated the allele frequency of the polymorphic CGG repeat in the 5'-UTR of the VLDL-R gene using a data set of 84 Caucasian AD patients with 104 Caucasian controls. Although the allele frequency of the 8-repeat allele was slightly lower, and that of 9-repeat allele was slightly higher, in the Caucasian AD patients than in Caucasian controls, the differences were not statistically significant. Multiple logistic regression analysis using apolipoprotein E4 (APOE4) allele, 5, 8-, or 9-repeat allele of the VLDL-R gene, sex, and age at onset as the predictors revealed that only the APOE4 allele was significantly associated with AD in the data set of the Caucasian AD patients and controls.

Aged↗
PubMed1996

Gamma delta T cells are secondary participants in acute graft-versus-host reactions initiated by CD4+ alpha beta T cells.

To examine the role of T cell subpopulations in an acute graft-versus-host (GVH) reaction, gamma delta T cells and alpha beta T cells expressing one of the two prototypic V beta families were negatively isolated from adult blood samples and injected into allogeneic chick embryos. CD4+ alpha beta T cells expressing either V beta 1 or V beta 2 receptors were equally capable of inducing acute GVH reactions, consistent with the idea that alpha beta T cell alloreactivity is determined by CDR3 variability. By themselves, the gamma delta T cells were incapable of inducing GVH reactions. However, host gamma delta T cells were recruited into the donor alpha beta T cell-initiated lesions, where they were activated and induced to proliferate. The data suggest that gamma delta T cells may play a secondary role in GVH reactions.

Acute Disease↗
PubMed1996

Decrease in benzodiazepine receptor binding in a patient with Angelman syndrome detected by iodine-123 iomazenil and single-photon emission tomography.

A receptor mapping technique using iodine-123 iomazenil and single-photon emission tomography (SPET) was employed to examine benzodiazepine receptor binding in a patient with Angelman syndrome (AS). AS is characterized by developmental delay, seizures, inappropriate laughter and ataxic movement. In this entity there is a cytogenic deletion of the proximal long arm of chromosome 15q11-q13, where the gene encoding the GABAA receptor beta3 subunit (GABRB3) is located. Since the benzodiazepine receptor is constructed as a receptor-ionophore complex that contains the GABAA receptor, it is a suitable marker for GABA-ergic synapsis. To determine whether benzodiazepine receptor density, which indirectly indicates changes in GABAA receptor density, is altered in the brain in patients with AS, we investigated a 27-year-old woman with AS using 123I-iomazenil and SPET. Receptor density was quantitatively assessed by measuring the binding potential using a simplified method. Regional cerebral blood flow was also measured with N-isopropyl-p-[123I]iodoamphetamine. We demonstrated that benzodiazepine receptor density is severely decreased in the cerebellum, and mildly decreased in the frontal and temporal cortices and basal ganglia, a result which is considered to indicate decreased GABAA receptor density in these regions. Although the deletion of GABRB3 was not observed in the present study, we indirectly demonstrated the disturbance of inhibitory neurotransmission mediated by the GABAA receptor in the investigated patient. 123I-iomazenil with SPET was useful to map benzodiazepine receptors, which indicate GABAA receptor distribution and their density.

Adult↗
PubMed1996

Assignment of the human ST2 gene to chromosome 2 at q11.2.

The human St2 locus has been assigned to chromosome 2, using a human ST2 cDNA clone, by a human/rodent somatic cel hybrid mapping panel. The St2 locus has also been mapped to chromosome 2q11.2, using a human ST2 genomic DNA clone, by in situ hybridization. The locus is very tightly linked to the Il-1r1 locus. Together with the structural similarity of ST2 to IL-1RI, these data suggest functional relationships between these two genes.

Animals↗
PubMed1996

Changes in factor VIII binding capacity of von Willebrand factor and factor VIII coagulant activity in two patients with type 2N von Willebrand disease after hemostatic treatment and during pregnancy.

The changes of the FVIII binding capacity of vWF after the infusion of FVIII/vWF concentrate was studied in two patients with type 2N vWD, and also during pregnancy in one of them. After infusion of FVIII or DDAVP to the patients, FVIII:C in plasma increased as expected, but it then decreased, with a markedly short half-life, of about 2 h, due to the defect in the FVIII binding capacity of vWF in plasma. However, after infusion of FVIII/vWF concentrate (40 U of FVIII:C/kg), FVIII:C increased, from 4-6 to 100-160 U/dl, more than the expected values, and decreased with the half-life expected. The FVIII binding capacity of vWF in plasma changed in parallel with the concentration of exogenous normal vWF, with a half-life of more than 24 h. During pregnancy, no increase of FVIII:C was observed, although vWF:Ag increased from 40 (before pregnancy) to 90 U/dl in plasma at 35th week of gestation. The FVIII binding capacity of vWF in plasma showed no increase during pregnancy. Accordingly, the administration of FVIII/vWF concentrate to the patient at delivery resulted in adequate hemostasis.

Deamino Arginine Vasopressin↗
PubMed1996

New evidence for the occurrence of a glycolipid-mediated signal transduction system.

Gangliosides have attracted particular attention in the field of brain research, since they were found not only to be abundant in neural tissue but also to have intricate structures in synaptic membranes. A murine neuroblastoma cell line, Neuro2a, expresses negligible amounts of GM3 and b-series gangliosides, but significant amounts of a-series gangliosides (GM1 and GD1a). With the transfection of cDNA encoding GD3 synthase, the de novo synthesis and expression of GD3 and b-series gangliosides occurred, and, furthermore, it induced the growth of axon-like neurites and cholinergic differentiation of Neuro2a cells. On the other hand, with the transfection of an alpha 1,2-fucosyltransferase, the axon-like neurite outgrowth was suppressed and dendrite-like neurites were outgrowth. These observations directly demonstrate the primary importance of the gene expression of a glycosyltransferase, and of the subsequent biosynthesis of gangliosides and their expression on the cell surface for neural cell development and differentiation.

Animals↗
PubMed1996

Central phenotype and related varieties of spinocerebellar ataxia 2 (SCA2): a clinical and genetic study with a pedigree in the Japanese.

The gene for SCA2 has been mapped to chromosome 12q23-q24.1, but the mutant gene remained to be identified. When studying a Japanese family with SCA2, we noted that clinical features and disability varied among patients, with the central feature being progressive ataxia-slow eye movement-hyporeflexia syndrome. Additional symptoms were parkinsonism with minor cerebellar deficits, and severe ataxia with choreoathetosis. Our experience plus related literature documentation indicates that choreoathetosis is not so rare at the advanced stage of the disease, with onset at an early age, and that the variety of SCA2 phenotype depends on age at onset and duration of the disorder.

Adult↗