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T Inaba

Publications and source records attributed to T Inaba.

At least 217 records · Page 12Linked to original sources
PubMed1994

Chromosomal localization and cDNA cloning of the human DBP and TEF genes.

We have isolated cDNA and genomic clones and determined the human chromosome positions of two genes encoding transcription factors expressed in the liver and the pituitary gland: albumin D-site-binding protein (DBP) and thyrotroph embryonic factor (TEF). Both proteins have been identified as members of the PAR (proline and acidic amino acid-rich) subfamily of bZIP transcription factors in the rat, but human homologues have not been characterized. Using a fluorescence in situ hybridization technique, the DBP locus was assigned to chromosome 19q13, and TEF to chromosome 22q13. Each assignment was confirmed by means of human chromosome segregation in somatic cell hybrids. Coding sequences of DBP and TEF, extending beyond the bZIP domain to the PAR region, were highly conserved in both human-human and interspecies comparisons. Conservation of the exon-intron boundaries of each bZIP domain encoding exon suggested derivation from a common ancestral gene. DBP and TEF mRNAs were expressed in all tissues and cell lines examined, including brain, lung, liver, spleen, and kidney. Knowledge of the human chromosome locations of these PAR proteins will facilitate studies to assess their involvement in carcinogenesis and other fundamental biological processes.

Amino Acid Sequence↗
PubMed1994

Increase of UDP-glucuronosyltransferase activities toward xenobiotics during the development of hereditary hepatitis in LEC rats.

UDP-glucuronosyltransferase activities were induced spontaneously during the development of hepatitis in LEC (Long Evans Cinnamon-like coat color) rats. Transition of hepatic microsomal UDP-glucuronosyltransferase activities was observed during the development of the LEC rat, which displayed spontaneous fulminant hepatitis with severe jaundice at about 12-16 weeks after birth. UDP-glucuronosyltransferase activities toward various substrates in 8-week-old LEC and LEA (Long Evans Agouti coat color; control) rats were similar. After 8 weeks of age, the transferase activities of LEA rats towards all substrates tested, except for bilirubin, decreased slightly during the next 24 weeks. In LEC rats, the transferase activities towards serotonin and several phenolic xenobiotics, such as 4-nitrophenol, 1-naphthol and 4-methylumbelliferone, but not 4-hydroxybiphenyl, increased about 2-fold at 16 weeks of age. During the 24 weeks following the first 8 weeks of age, the high level activities towards the xenobiotics continued, with the exception of bilirubin transferase activity which decreased gradually. These results suggest that a form of UDP-glucuronosyltransferase, which catalyzes the glucuronidations of serotonin and these xenobiotics except for 4-hydroxybiphenyl, is induced during the development of hepatitis in the LEC rat.

Animals↗
PubMed1994

Inter-individual variability of human hepatic glutathione S-transferase isozymes assessed by inhibitory capacity.

Glutathione S-transferases (GSTs) are important as drug metabolizing enzymes mainly in the detoxication process. To assess individual differences in susceptibility to different chemicals, it would be useful to know the activity of specific GST isozymes in individuals. In order to study individual variability, typical substrates specific for the three major classes of GSTs were used not only as substrates but also as inhibitors using 17 organ-donor livers. Out of 17, 4 livers were low in the mu-form isozyme, judging from the depressed GST activity for trans-4-phenyl-3-buten-2-one (tPBO), a mu-class substrate. The range of tPBO activity exhibited more than 20-fold variation, while less than 2-fold variation was observed in the activities for 1-chloro-2,4-dinitrobenzene (CDNB), a non-specific substrate for alpha-, mu-, and pi-class GSTs. In addition to the conventional approach to assessing individual variability, well known substrates for GSTs, cumene hydroperoxide (CHP, alpha-class), tPBO (mu) and ethacrynic acid (EA, pi) were used as inhibitors against CDNB-GSH conjugation. CHP inhibited the CDNB-GSH conjugation in mu-depressed livers more potently than in the non-depressed livers, probably because CHP is a specific inhibitor for alpha-class GST. Inhibition by CHP may therefore be used to detect livers which are low in mu-form. The inhibition by tPBO was found to be weak and the variability was small (CV of 9% in 17 livers). EA potently inhibited GST activity with its inhibition constant (Ki) 2,000-fold lower than that of CHP. The small individual variation in inhibition by EA (CV of 6%) supported that EA is a universal but potent inhibitor against major GSTs contained in human liver.

Benzene Derivatives↗
PubMed1994

IgE plasma cell leukemia successfully treated with combination VAD (vincristine, doxorubicin, dexamethasone) and MP (melphalan, prednisolone) followed by interferon-alpha.

A 69-year-old woman with IgE/kappa plasma cell leukemia (PCL) was treated with a sequential combination of VAD (vincristine, doxorubicin, dexamethasone) and MP (melphalan, prednisolone) followed by interferon-alpha (IFN alpha). A complete remission was achieved for 14 months. Maintenance therapy with IFN alpha has continued for an additional 10 months. IgE PCL is extremely rare. The biological characteristics of the myeloma cells, including surface marker, adhesion molecule, karyotype, DNA analysis, and the response to various cytokines, are presented.

Aged↗
PubMed1994

Trichosporon cutaneum fungemia in patients with acute myeloblastic leukemia and measurement of serum D-arabinitol, Candida antigen (CAND-TEC), and beta-D-glucan.

Two patients with acute myeloblastic leukemia are described who developed fungemia due to Trichosporon cutaneum. Fungemia occurred at the leukocyte nadir following the administration of anti-cancer chemotherapy. One patient was cured but the other died. Both patients received prednisolone continuously and had central venous catheters in place for parenteral hyperalimentation. T. cutaneum isolates were resistant to 5-fluorocytosine and moderately susceptible to fluconazole. One case was complicated by endophthalmitis due to T. cutaneum; this is the second report of such a complication in the world. We investigated the serum levels of beta-D-glucan, D-arabinitol, and Candida antigen (CAND-TEC); beta-D-glucan was elevated in both cases, which suggests that simultaneous measurements of these laboratory values are useful for the diagnosis and possibly for the evaluation of therapy for this fungal infection.

Antigens, Fungal↗
PubMed1994

Dextran sulfate, a competitive inhibitor for scavenger receptor, prevents the progression of atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Dextran sulfate competes with binding of modified LDL to the scavenger receptor in macrophages. To elucidate the role of dextran sulfate in the atherosclerotic process, 100 mg of dextran sulfate in drinking water was given to 5 Watanabe heritable hyperlipidemic (WHHL) rabbits for 12 months starting at age 4 months. During the experimental period, there were no significant differences in plasma cholesterol levels between dextran sulfate-treated and untreated rabbits. After 12 months' treatment, accumulation of cholesterol ester in total aorta was significantly suppressed in dextran sulfate-treated rabbits as compared with untreated rabbits (71.4 +/- 22.3 vs. 42.7 +/- 16.5 mg/g dry weight, P < 0.05). Furthermore, lesion area with atherosclerotic plaques in treated rabbits was significantly less than that in untreated rabbits (59.7 +/- 24.5 vs. 30.4 +/- 14.4%, P < 0.05). These results indicate that dextran sulfate might prevent the progression of atherosclerosis by competitively inhibiting the binding of modified LDL to scavenger receptors.

Animals↗
PubMed1994

Developmental changes in testicular luteinising hormone receptors and androgens in the dog.

The changes with age in the levels of testicular luteinising hormone (LH) receptors in dogs, were correlated with plasma androgen concentrations and the effects of stimulation with human chorionic gonadotrophin (hCG). The presence of high-affinity binding sites for LH was demonstrated in the testes of all the animals studied, and the apparent affinity of the LH receptors did not change significantly with age. The total number of LH receptor sites per testis increased continuously with age and the growth of the testis. The major rise in the number of LH receptors occurred between six and 10 months of age, and coincided with the phase of rapid testicular growth. The concentrations of androstenedione, testosterone and 5 alpha-dihydrotesterone in plasma increased gradually until six months of age, and then increased rapidly with the increase in the number of testicular LH receptors. An increase in the concentrations of androgens in plasma was observed in response to stimulation with hCG after the number of testicular LH receptors began to increase progressively. The increase in the sensitivity of the dogs' gonads to LH could be responsible for the marked increase in the secretion of androgens which occurs during puberty in the male dog.

Androgens↗
PubMed1994

The hair follicular cycle of the cryptothrix mouse and the characteristics of its abnormal hair.

The hair follicular changes of the cryptothrix mutant mouse (crh mouse) were examined sequentially from birth to 365 days of age and the characteristics of the abnormal hair were observed. The homozygous crh mouse had no hair coat on the skin surface during the period of observation, but a small number of fuzzy soft hairs in the black pigmented skin of the anagen phase was seen. Cyclic folliculogenesis, however, was observed histologically in the dermis. The first anagen phase developed at 3 to 4 days of age and lasted until about 15 days of age. The hair follicles then entered the telogen phase, which lasted until about 18 to 32 days of age. Thereafter, the follicular cycles were repeated three times about every 20 days until 90 days of age. This pattern coincided well with the normal hair cyclic pattern reported for the mouse and rat. After 100 days of age, however, alternating anagen and telogen phases formed a striped pattern in the skin, with black bands. These black bands became progressively thinner and shifted anteriorly, showing a wavy pattern. The abnormal hair of the homozygous crh mouse showed separation of the hair medulla due to incomplete trichilemmal keratinization in the internal root sheath. The tips of the hair shafts were folded and collapsed under the epidermis and did not erupt on the skin surface. The hair follicles, however, did not differ from those of heterozygous crh mice. Because the homozygous crh mouse failed to form a complete hair shaft, cyclic folliculogenesis of the epidermis could be easily observed macroscopically without depilation. The homozygous crh mouse may prove useful in evaluating new drugs for hair follicular growth.

Animals↗
PubMed1994

Mouse anti-human interleukin-6 receptor monoclonal antibody inhibits proliferation of fresh human myeloma cells in vitro.

Interleukin-6 (IL-6) is a major growth factor in multiple myeloma. We investigated the effect of mouse anti-human IL-6 receptor monoclonal antibody (anti-IL-6R mAb) on the in vitro proliferation of freshly isolated myeloma cells from 21 patients to evaluate the therapeutic potential. The addition of anti-IL-6R mAb inhibited more than 30% of the spontaneous proliferation of myeloma cells in 9 of 21 cases in a dose- (0.1 to 20 micrograms/ml) and time-dependent manner. The inhibitory effects of anti-IL-6R mAb did not differ significantly from that of anti-IL-6 mAb, and were correlated with the extent of the response of myeloma cells to IL-6. Flow cytometric analysis showed that all myeloma cells expressed IL-6R, whose intensity was not correlated with either the extent of response of myeloma cells to IL-6 or the inhibitory effects of anti-IL-6R mAb on proliferation of myeloma cells. Although our study showed heterogeneity in the proliferative responses of myeloma cells to IL-6 and anti-IL-6R mAb, these observations suggest the possibility of using anti-IL-6R mAbs for treating some patients with multiple myeloma whose growth depends on IL-6.

Animals↗
PubMed1994

Kinetics of serum cytokines in adults undergoing peripheral blood progenitor cell transplantation.

We investigated the serum cytokine levels (G-CSF, GM-CSF, IL-1 beta, IL-3 and IL-6) using an ELISA in 14 patients with haematological malignancies undergoing peripheral blood progenitor cell transplantation (PBPCT). Serum G-CSF levels in all patients rose immediately after PBPCT, then gradually decreased as the neutrophil counts began to rise. No detectable serum levels of GM-CSF or IL-1 beta were observed, but serum levels of IL-3 rose transiently immediately following PBPCT. Serum levels of IL-6 rose transiently during a fever in four patients. These observations suggest that G-CSF and IL-3 may contribute to the early haemopoietic reconstitution in PBPCT.

Adolescent↗
PubMed1994

DNA-binding specificity and trans-activating potential of the leukemia-associated E2A-hepatic leukemia factor fusion protein.

Hybrid transcription factors, resulting from gene fusions in the wake of chromosomal translocations, have been implicated in leukemogenesis, but their precise contributions to oncogenic conversion remain unclear. The E2A-HLF fusion gene, formed by a t(17;19)(q22;p13) in childhood pro-B-cell acute lymphoid leukemia, encodes a hybrid protein that contains the trans-activation domain of E2A (E12/E47) linked to the bZIP DNA-binding and dimerization domain of hepatic leukemia factor (HLF). Here we report that both HLF and E2A-HLF bind to a 10-bp consensus sequence, 5'-GTTACGTAAT-3', with a core dyad-symmetric motif characteristic of the bZIP scissors-grip model of DNA binding. A probe containing this sequence bound chimeric E2A-HLF proteins in nuclear extracts of a leukemic cell line (UOC-B1) containing the t(17;19), as demonstrated by complexes supershifted with antibodies specific for amino-terminal epitopes of E2A or carboxyl-terminal eptiopes of HLF. E2A-HLF functioned as a potent trans activator of reporter gene expression from a plasmid that contained the consensus DNA-binding sequence. Interestingly, wild-type HLF was restricted in its capacity to act as a trans activator, functioning in human fetal kidney cells but not HepG2 hepatocarcinoma cells or NIH 3T3 mouse fibroblasts. The ability of the E2A-HLF hybrid protein to bind DNA in a sequence-specific manner and trans activate the expression of artificial reporter genes suggests that it could subvert transcriptional programs that normally control the growth, differentiation, and survival of lymphoid progenitor cells.

3T3 Cells↗
PubMed1994

Overexpression of human lipoprotein lipase enhances uptake of lipoproteins containing apolipoprotein B-100 in transfected cells.

To investigate the role in lipoprotein metabolism of lipoprotein lipase (LPL) secreted by tissues, we established two cell lines. Fusion plasmids containing either human LPL cDNA or antisense LPL cDNA under control of the cytomegalovirus promoter were transfected into Chinese hamster ovary (CHO) cells, designated as CHO-LPL and CHO-anti-LPL, respectively. CHO-LPL constitutively produced a high level of LPL, whereas CHO-anti-LPL produced a minimal level. When very-low-density lipoprotein (VLDL) was incubated with CHO-LPL, VLDL triglycerides were hydrolyzed, intermediate-density lipoprotein (IDL) was produced, and apolipoprotein E contents increased. CHO-LPL took up and degraded 125I-VLDL at 37 degrees C four times more strongly than did CHO-anti-LPL. Whereas the degradation of apolipoprotein E-deficient VLDL was only 12% that of normal VLDL in CHO-LPL, structural changes of the lipoprotein, including apolipoprotein E expression on the lipoprotein surface, may be important for the cellular uptake of VLDL. Furthermore, we found that binding at 4 degrees C of VLDL and LDL to CHO-LPL was greater than to CHO-anti-LPL, and this binding difference was abolished by washing the cells with heparin. This suggests that cell surface LPL plays a role in the binding of lipoproteins to the cells. We conclude that both the composition of VLDL particles and their cellular binding are influenced by LPL secreted by cells, both of which may enhance the cellular uptake of VLDL.

Animals↗
PubMed1994

Induction of LDL receptor-related protein during the differentiation of monocyte-macrophages. Possible involvement in the atherosclerotic process.

The low-density lipoprotein receptor-related protein (LRP) is a multifunctional receptor that binds to apolipoprotein E-rich lipoproteins, lipoprotein lipase, alpha 2-macroglobulin, lactoferrin, and tissue plasminogen activator. We studied the mRNA expression of LRP in human monocyte-derived macrophages and THP-1 cells. mRNA expression of LRP was induced during cell differentiation from human monocytes to macrophages or after incubation with phorbol ester (tetradecanoylphorbol acetate 100 ng/mL) in THP-1 cells, and the addition of 30 ng/mL macrophage colony-stimulating factor further enhanced LRP expression. These results indicated that the expression of LRP depended on the stage of differentiation and maturation of monocytic cells. mRNA expression of LRP was also enhanced in human monocyte-derived macrophages in the presence of acetylated low-density lipoprotein and in aorta of rabbits fed a high-cholesterol diet. We hypothesize that the LRP induced in monocyte-derived macrophages is involved in the initial process of atherosclerosis by interacting with its multiple ligands.

Animals↗
PubMed1994

Proteoglycan form of macrophage colony-stimulating factor binds low density lipoprotein.

We recently isolated a proteoglycan form of macrophage colony-stimulating factor (PG-M-CSF) that carries a chondroitin sulfate glycosaminoglycan chain. Here, we examined the interaction of PG-M-CSF with low density lipoprotein (LDL). When LDL preincubated with PG-M-CSF was fractionated by molecular size sieving chromatography, it was eluted earlier than untreated LDL. When LDL was preincubated with chondroitin sulfate-free 85-kD M-CSF instead of PG-M-CSF, the elution profile of LDL remained unchanged, indicating specific interaction between PG-M-CSF and LDL. The level of PG-M-CSF binding in the wells of a plastic microtitration plate precoated with LDL was significant, this binding being completely abolished by pretreatment of PG-M-CSF with chondroitinase AC, which degrades chondroitin sulfate. The addition of exogenous chondroitin sulfate or apolipoprotein B inhibited the binding of PG-M-CSF to LDL in a dose-dependent manner, indicating that the interaction between PG-M-CSF and LDL was mediated by the binding of the chondroitin sulfate chain of PG-M-CSF to LDL apolipoprotein B. PG-M-CSF was also demonstrated in the arterial wall, and there were increased amounts of PG-M-CSF in atherosclerotic lesions. The in vitro interaction between PG-M-CSF and LDL thus appears to have physiological significance.

Aorta↗
PubMed1994

Expression of c-fms on smooth muscle cells isolated from experimental arteriosclerosis.

In the present study, we demonstrated gene transcription of c-fms in smooth muscle cells isolated from an experimental rabbit model of arteriosclerosis (intimal smooth muscle cells), although there was no gene transcription of c-fms detected in medial smooth muscle cells. On immunocytochemical analysis, both types of smooth muscle cells similarly reacted with an antibody specific to muscle cells (HHF 35), but did not react with an antibody specific to rabbit macrophages (RAM 11). Intimal smooth muscle cells bound to acetylated LDL and resulting foam cell formation was observed. In response to M-CSF, an increased rate of cell proliferation was observed in intimal smooth muscle cells, but not in medial smooth muscle cells. These results indicated that intimal smooth muscle cells have monocyte-macrophages characteristics such as the expression of c-fms and scavenger receptor gene.

Animals↗
PubMed1994

Effect of granulocyte colony-stimulating factor on hematopoietic recovery after peripheral blood progenitor cell transplantation.

To examine the effect of granulocyte colony-stimulating factor (G-CSF) on hematopoietic recovery after high-dose chemotherapy and peripheral blood progenitor cell transplantation (PBPCT), 20 patients with hematologic malignancies were divided into two groups. One group was given G-CSF at a daily dose of 50 micrograms/m2 subcutaneously, the other received no G-CSF. Neutrophil recovery was accelerated in the G-CSF treated patients and exceeded 0.5 x 10(9)/l at a median of 10 days post-PBPCT compared with 14 days in the control group (p < 0.01). This reduction led to a decrease in antibiotic use and a trend toward fewer febrile days in the G-CSF treated group.

Adolescent↗