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T Kayano

Publications and source records attributed to T Kayano.

At least 37 records · Page 2Linked to original sources
PubMed1997

Characterization of anti-human interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) monoclonal antibodies and their application in the measurement of human IL-18 by ELISA.

Interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) is a novel cytokine, which is a potent inducer of IFN-gamma production and plays an important role in Th1 responses. In order to develop a specific ELISA for the measurement of human IL-18, we established 13 anti-human IL-18 monoclonal antibodies and characterized them. 7 murine anti-human IL-18 mAbs and 6 rat anti-human IL-18 mAbs were obtained by fusion of splenocytes from mice or rats immunized with human IL-18, with SP2/0 myeloma cells. These antibodies were classified into 4 groups according to competitive binding ELISAs to the human IL-18 molecule. 1 murine mAb and all 6 rat mAbs neutralized IFN-gamma production induced by IL-18. A specific human IL-18 ELISA was developed using two neutralizing mAbs (#125-2H and #159-12B). This ELISA detects human IL-18 with a minimum detection limit of 10 pg/ml, but does not react with heat-denatured human IL-18. The ELISA does not show any cross-reactivity with other cytokines. Using this assay, human IL-18 was measurable in the plasma of leukemia patients. This ELISA would become a powerful tool for investigating the relationship between IL-18 and various diseases or analyzing the control mechanisms of IL-18 production from IL-18 producing cells.

Adult↗
PubMed1997

No significant role of Epstein-Barr virus in the tumorigenesis of Warthin tumor.

To determine the significance of Epstein-Barr virus (EBV) in the tumorigenesis of Warthin tumor, formaldehyde-fixed and paraffin-embedded specimens of 21 tumors from 18 patients were examined by polymerase chain reaction (PCR)-Southern hybridization, in situ hybridization (ISH), and immunohistochemistry. PCR-Southern hybridization revealed the presence of EBV DNA in 13 of the 21 tumors (61.9%). However, ISH for EBV RNA showed that nuclei of the neoplastic epithelial cells of all tumors were negative. Although ISH for EBV DNA revealed that the nuclei of the neoplastic epithelial cells were positive in 4 of the 21 tumors (19.0%), the positive cells were sparsely distributed and there was no evidence of monoclonal proliferation of EBV positive neoplastic epithelial cells. Moreover, immunohistochemical reactions with antibodies against latent membrane protein 1 (LMP1) and EBV nuclear antigen 2 (EBNA2), were negative in all cases. Judging from these findings, we conclude that EBV does not play a major role in the tumorigenesis of Warthin tumor.

Adenolymphoma↗
PubMed1996

Interferon-gamma-inducing factor, a novel cytokine, enhances Fas ligand-mediated cytotoxicity of murine T helper 1 cells.

Fas ligand (FasL), expressed on activated T cells, plays a central role in regulating the immune response by inducing apoptosis in activated lymphocytes through binding to its receptor, Fas. We report here that a newly discovered cytokine, interferon-gamma-inducing factor (IGIF) (H. Okamura et al., Nature 378, 88, 1995), selectively enhances the FasL-mediated cytotoxicity of cloned murine Th1 cells, but not Th0 or Th2 cells. Anti-IFN-gamma antibody (Ab) did not block the IGIF-induced cytotoxicity of Th1 cells, nor did IFN-alpha, IFN-gamma, or TNF-alpha augment the cytotoxic activity of Th1, thus indicating that this enhanced cytotoxicity of Th1 cells was mediated by IGIF. In addition, IL-12 was also found to enhance the FasL-mediated cytotoxicity of Th1 cells, suggesting that Th1 cells possesses receptors for both cytokines although these cytokines can act via different pathways. The results thus show that IGIF, recently proposed as IL-18, might play a potential role in immunoregulation or in inflammation by augmenting the functional activity of FasL on Th1 cells.

Animals↗
PubMed1996

Two transcripts with different sizes derived from a rice homeobox gene, OSH1.

A rice homeobox gene, OSH1, contains two functionally independent promoters which generate a larger transcript and a smaller transcript. In Arabidopsis, each promoter can drive the expression of a reporter gene in a different manner, indicating that the expression of different sized transcripts is independently regulated by each promoter. Over-expression of the larger transcript in transformed plants caused altered morphologies (Matsuoka et al., Plant Cell, 1993, 5, 1039-1048); in contrast, over-expression of the smaller transcript did not cause any morphological changes. The results suggest that the product of the smaller transcript fails to alter the expression of its target gene(s) in the transformants, while that of the larger transcript is capable of altering the expression of its target gene(s).

Amino Acid Sequence↗
PubMed1995

Differential display identifies developmentally regulated genes during somatic embryogenesis in eggplant (Solanum melongena L.).

Changes in gene expression patterns during early somatic embryogenesis of eggplant (Solanum melongena L.) were characterized by means of differential display. Eight products of polymerase chain reaction (PCR) derived from newly expressed mRNAs after four days of culture were identified and cloned. One clone, pTM002, was found to contain a 416 bp insert and identical to the proximal arbitrary primer at both ends. Based on the terminal sequences, reverse-transcription PCR (RT-PCR) was carried out to monitor the expression level of pTM002. The results indicated that the message of pTM002 was increased to correlate with the intensities obtained in the differential display. The significance of this method in investigation of differentially expressed genes is also discussed.

Base Sequence↗
PubMed1995

Alternative RNA products from a rice homeobox gene.

Three cDNA clones were isolated from rice, OSH42, OSH44 and OSH45, which encode homeodomain sequences in the C-terminal region. The sequences of these cDNAs differ in the N- and C-termini, but they share an identical homeodomain and an acidic amino acid-rich region. The transcripts corresponding to these cDNAs are encoded by a single gene on rice chromosome 8. Differential transcription initiation results in a large transcript comprised of exons 1 and 3-7 and a smaller transcript comprised of exons 2-7. The larger transcript is constitutively expressed in all tissues tested, while the smaller transcript is expressed in leaves, stems and rachis but not in roots, flowers, or suspension callus cells. Alternative splicing also occurs at three different acceptor sites in intron 6 in all tissues tested. The GAL4 DNA-binding domain of yeast was used to study the function of various protein domains. The acidic amino acid-rich region activates the expression of a reporter gene controlled by the GAL4 target sequence, indicating that it functions as a transactivation domain. The larger transcript encodes a unique alanine and glycine-rich region on the N-terminal side of the acidic region, which is not encoded by the smaller transcript. This region completely suppresses the transactivation activity of the acidic region. This suggests that the product of the larger transcript fails to activate the expression of the target gene(s) while the product of the smaller transcript activates the expression of its target gene(s).

Alternative Splicing↗
PubMed1994

Carcinogen daily dose-dependence of the biological features and development rate of hepatocellular carcinomas induced by 3'-methyl-4-dimethylaminoazobenzene in the rat.

Differences in biological features and the rate development of hepatocellular carcinomas (HCCs) induced with various daily doses of 3'-methyl-4-dimethylaminoazobenzene were investigated. Male Donryu rats at 21 days old were fed the carcinogen at concentrations ranging from 50 to 600 ppm in the diet continuously, or 600 ppm for 3 weeks followed by a dietary promoting regimen of 500 ppm phenobarbital. Large (> or = 10 mm) HCCs were monitored and the histological features and alpha-fetoprotein (AFP) production analysed. High doses of the carcinogen predominantly induced HCCs of high grade malignancy with AFP production in a short latent period whereas lower doses and the initiation-promotion protocol were primarily associated with low grade HCCs lacking AFP production and developing after long latent periods. Thus the experimental results clearly document that biological features of neoplasms, viewed as a spectrum, may markedly differ according to the daily dose of the carcinogen applied.

Animals↗
PubMed1993

Epitopes on Cry j I and Cry j II for the human IgE antibodies cross-reactive between Cupressus sempervirens and Cryptomeria japonica pollen.

Forty sea from French patients allergic to Cupressus sempervirens pollen were tested for cross-reactivities against Cry j I, Cry j II (major allergens of Cryptomeria japonica pollen) and other pollen allergens from botanically related plants. Seventy-three per cent of the sera reacted with either Cry j I or Cry j II, or with both of them. These IgE cross-reactions were blocked effectively by mAb 046 (anti-Cry j I) or N26, T27 (anti-Cry j II), and weakly by mAbs 052, 027 and 026 (anti-Cry j I). Furthermore, the IgE antibodies in two sera, #40 and #11, bound to peptide fractions obtained from enzyme-digested Cry j I, and mAb 027 could also bind to the fractions. Analyses of the amino acid sequences of the peptides revealed that reactive peptides contained "NGNATPQLTKNAGVLTCSLSKR" sequence and the third residue N3 was glycosylated, however, when the N3 was not glycosylated, the IgE antibodies did not react, but mAb 027 could. The glycosylation of the N3 might be required for IgE-binding to the peptides. Sugar component on the N3 residue was found to be 0.4 mol galactose, 1.3 mol mannose, 0.8 mol fucose and 2.0 mol N-acetyl-glucosamine. Cross-reactivities against other pollen allergens from botanically related plants were found in most of the sera. However, many of these reactivities were detected by sandwich ELISA but not by an ELISA using allergen-coated plates, indicating that it is important to select an appropriate ELISA procedure in order to detect an allergen or an IgE antibody to an allergen.

Allergens↗
PubMed1993

Organization of the human GLUT2 (pancreatic beta-cell and hepatocyte) glucose transporter gene.

The gene encoding the predominant facilitative glucose transporter expressed in pancreatic beta-cells and hepatocytes, termed GLUT2, has been cloned and characterized. The human GLUT2 gene is composed of 11 exons spanning approximately 30 kilobases. The sequence of the promoter region and all exons and adjacent intron regions has been determined and deposited in the GenBank database. Two highly polymorphic simple tandem repeat DNA polymorphisms useful for linkage studies were localized in introns 1 and 4a. In addition, a 168-base pair insertion/deletion polymorphism was identified in intron 3. The characterization of the human GLUT2 gene will facilitate studies of its role in the development of diabetes mellitus.

Amino Acid Sequence↗
PubMed1992

Causes of oral tongue cancer treatment failures. Analysis of autopsy cases.

Eighty-three autopsy cases of squamous cell carcinoma of the oral tongue were reviewed to identify retrospectively the causes of treatment failure. The cure rate for the primary cancers at autopsy was 48.2% (40 of 83). Regional lymph node metastases were found in 71.1% (59 of 83). Regional metastases and/or juxtaprimary recurrence frequently spread continuously and diffusely, forming bulky neck tumors in 38.6% (32 of 83). The incidence of distant lymph node metastasis (below the clavicle) and hematogenous metastasis was 35.4% (29 of 82) and 58.5% (48 of 82), respectively. The lung was the most common site of hematogenous metastases (52.4%, 43 of 82). Hematogenous metastasis occurred more frequently in the younger age group (less than 40 years of age; P = 0.03). Distant lymph node metastases were identified in the lung hilar, bifurcation, and paratracheal nodes in 89.7% (26 of 29) and had a statistically significant association with lung hematogenous metastasis. Univariate analysis revealed that gross appearance, tumor stage, clinical stage, presence of cervical lymph node metastasis, and interval from N0 to NX were significant predictors of survival time (duration from initial treatment to death). Rupture of the neck vessels was fatal in eight patients (9.6%), and hypercalcemia was seen in six (7.2%). Pulmonary infection was the direct cause of death in 33.7% of patients (28 of 83). Secondary malignant lesions occurred in 22.9% (19 of 83).

Adult↗
PubMed1990

Human facilitative glucose transporters. Isolation, functional characterization, and gene localization of cDNAs encoding an isoform (GLUT5) expressed in small intestine, kidney, muscle, and adipose tissue and an unusual glucose transporter pseudogene-like sequence (GLUT6).

Two novel facilitative glucose transporter-like cDNAs have been isolated from human small intestine and fetal skeletal muscle cDNA libraries by low stringency cross-hybridization with a fragment of the human erythrocyte/GLUT1 facilitative glucose transporter cDNA. One encodes a 501-amino acid facilitative glucose transporter, designated as the small intestine/GLUT5 isoform, having 41.7, 40.0, 38.7, and 41.6% identity with the previously described human erythrocyte/GLUT1, liver/GLUT2, brain/GLUT3, and muscle-fat/GLUT4 isoforms, respectively. GLUT5 mRNA is expressed at highest levels in small intestine and at much lower levels in kidney, skeletal muscle, and adipose tissue. Expression of in vitro synthesized human GLUT5 mRNA in Xenopus laevis oocytes indicates that the GLUT5 protein is a cytochalasin B-sensitive glucose carrier. The gene encoding the GLUT5 protein is located on the short arm of human chromosome 1. The second facilitative transporter-like cDNA sequence, designated GLUT6, is part of an 11-kilobase transcript that is expressed in all tissues examined. The sequence of a partial-length GLUT6 cDNA having an insert of 3.4 kilobase pairs revealed a region of 1.5 kilobase pairs that has 79.6% identity with the human brain/GLUT3 facilitative glucose transporter cDNA. However, because of the presence of multiple stop codons and frame shifts, this sequence cannot encode a functional glucose transporter protein. The region of facilitative glucose transporter nucleotide sequence homology in the GLUT6 transcript may have arisen by insertion of a reverse-transcribed GLUT3 transcript into the untranslated region of another gene. The GLUT6 gene is located on the long arm of human chromosome 5.

Adipose Tissue↗
PubMed1990

Growth of rat-mouse hybridoma cells in immunosuppressed hamsters. An easy and effective method to prepare monoclonal antibodies from heterohybridoma cell lines.

Rat-mouse hybridoma cells producing anti-mouse IgE antibodies were intraperitoneally or subcutaneously inoculated into newborn or suckling hamsters receiving rabbit anti-hamster thymocyte globulin from the day of birth twice a week for at least 3 weeks. The hybridoma cells were found to grow in the abdominal cavity of the hamsters as ascites tumor or in subcutaneous tissue as solid tumor without loss of antibody-secreting activities. For the production of ascites, 2-week-old hamsters were preferable to newborn hamsters. In 3-week-old hamsters, the hybridoma cells could scarcely survive. The antibody titers of the ascites were determined to be 10(5)-10(6) in the ELISA and in the ability to neutralize the skin-sensitizing capacity of mouse IgE antibodies. The rat monoclonal antibodies were easily separated from ascites, serum or cell culture supernatant with affinity chromatography using Affigel protein A-Sepharose and anti-hamster IgG-Sepharose columns. The described method could be efficiently applicable for the proliferation of other hybridomas, such as human-human, human-mouse or hamster-mouse, etc.

Animals↗
PubMed1990

Regulation of glucose transporter messenger RNA levels in rat adipose tissue by insulin.

Analysis of glucose transporter mRNA levels in adipose tissue from streptozotocin (STZ)-induced diabetic rats demonstrated a specific decrease (10-fold) in adipose tissue GLUT-4 mRNA with no significant effect on GLUT-1 mRNA levels. Treatment of STZ-diabetic rats with twice daily injections of insulin for 1-3 days resulted in a 16-fold increase in the relative amount of GLUT-4 mRNA to levels approximately 2-fold greater than those in control animals. However, after 7 days of insulin therapy the amount of GLUT-4 mRNA decreased approximately 2-fold back to the levels in the control animals. Normalization of the STZ-induced serum hyperglycemia by phlorizin treatment, which inhibits renal tubular reabsorption of glucose, had no effect on GLUT-4 mRNA in the absence of insulin. Similar to STZ-diabetes, fasting for 48 h also reduced adipose GLUT-4 mRNA levels. Parenteral administration of insulin with glucose over 7.5 h, but not glucose alone, increased the levels of the GLUT-4 mRNA 3- to 4-fold. These studies demonstrate that the relative glycemic state does not influence GLUT-4 glucose transporter mRNA expression in vivo and strongly suggests that insulin is a major factor regulating the levels of GLUT-4 mRNA in adipose tissue.

Adipose Tissue↗
PubMed1990

Molecular biology of mammalian glucose transporters.

The oxidation of glucose represents a major source of metabolic energy for mammalian cells. However, because the plasma membrane is impermeable to polar molecules such as glucose, the cellular uptake of this important nutrient is accomplished by membrane-associated carrier proteins that bind and transfer it across the lipid bilayer. Two classes of glucose carriers have been described in mammalian cells: the Na(+)-glucose cotransporter and the facilitative glucose transporter. The Na(+)-glucose cotransporter transports glucose against its concentration gradient by coupling its uptake with the uptake of Na+ that is being transported down its concentration gradient. Facilitative glucose carriers accelerate the transport of glucose down its concentration gradient by facilitative diffusion, a form of passive transport. cDNAs have been isolated from human tissues encoding a Na(+)-glucose-cotransporter protein and five functional facilitative glucose-transporter isoforms. The Na(+)-glucose cotransporter is expressed by absorptive epithelial cells of the small intestine and is involved in the dietary uptake of glucose. The same or a related protein may be responsible for the reabsorption of glucose by the kidney. Facilitative glucose carriers are expressed by most if not all cells. The facilitative glucose-transporter isoforms have distinct tissue distributions and biochemical properties and contribute to the precise disposal of glucose under varying physiological conditions. The GLUT1 (erythrocyte) and GLUT3 (brain) facilitative glucose-transporter isoforms may be responsible for basal or constitutive glucose uptake. The GLUT2 (liver) isoform mediates the bidirectional transport of glucose by the hepatocyte and is responsible, at least in part, for the movement of glucose out of absorptive epithelial cells into the circulation in the small intestine and kidney. This isoform may also comprise part of the glucose-sensing mechanism of the insulin-producing beta-cell. The subcellular localization of the GLUT4 (muscle/fat) isoform changes in response to insulin, and this isoform is responsible for most of the insulin-stimulated uptake of glucose that occurs in muscle and adipose tissue. The GLUT5 (small intestine) facilitative glucose-transporter isoform is expressed at highest levels in the small intestine and may be involved in the transcellular transport of glucose by absorptive epithelial cells. The exon-intron organizations of the human GLUT1, GLUT2, and GLUT4 genes have been determined. In addition, the chromosomal locations of the genes encoding the Na(+)-dependent and facilitative glucose carriers have been determined. Restriction-fragment-length polymorphisms have also been identified at several of these loci.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1989

Regulation of glucose transporter messenger RNA in insulin-deficient states.

Recent studies have indicated that a family of structurally related proteins with distinct but overlapping tissue distributions are responsible for facilitative glucose transport in mammalian tissues. Insulin primarily stimulates glucose transport by inducing the redistribution of a unique glucose transporter protein from an intracellular pool to the plasma membrane. This 509-amino-acid integral membrane protein, termed GLUT-4, is the main insulin-responsive glucose transporter in adipose and muscle tissues. We have observed a dramatic decrease (tenfold) in the steady-state levels of GLUT-4 messenger RNA in adipose tissue from fasted rats or rats made insulin deficient with streptozotocin. Insulin treatment of the streptozotocin-diabetic rats or refeeding the fasted animals causes a rapid recovery of the GLUT-4 mRNA to levels significantly above those observed in untreated control animals. By contrast, the levels of the erythrocyte/HepG2/rat brain-type glucose transporter mRNA remain essentially unchanged under these conditions. These data suggest that the in vivo expression of GLUT-4 mRNA in rat adipose tissue is regulated by insulin.

Animals↗