Biomedical subjects

Y Sugimoto

Publications and source records attributed to Y Sugimoto.

At least 181 records · Page 10Linked to original sources

PubMed1999

[The future of clinical laboratory database management system].

To assess the present status of the clinical laboratory database management system, the difference between the Clinical Laboratory Information System and Clinical Laboratory System was explained in this study. Although three kinds of database management systems (DBMS) were shown including the relational model, tree model and network model, the relational model was found to be the best DBMS for the clinical laboratory database based on our experience and developments of some clinical laboratory expert systems. As a future clinical laboratory database management system, the IC card system connected to an automatic chemical analyzer was proposed for personal health data management and a microscope/video system was proposed for dynamic data management of leukocytes or bacteria.

Clinical Laboratory Information Systems↗

PubMed1999

Effects of histamine and related compounds on regional cerebral blood flow in rats.

The effects of histamine and related compounds on regional cerebral blood flow (rCBF) in the hippocampus of conscious rats were studied. Intracerebroventricular injection of histamine caused a dose-dependent increase in rCBF in the hippocampus, and similar findings were observed with not only the H1 agonist, 2-thiazolylethylamine, but also the H2 agonist, dimaprit. Intraperitoneal injection of L-histidine also resulted in an increase in rCBF in the hippocampus, in parallel with elevation of histamine content in the brain. The increase in rCBF in the hippocampus induced by L-histidine was antagonized by both H1 and H2 antagonists (diphenhydramine, pyrilamine and zolantidine). In addition, when both antagonists were injected simultaneously, an additive effect was observed in antagonism of the L-histidine-induced increase in rCBF. L-Histidine caused no marked changes in blood pressure even at a dose of 1,500 mg/kg, which showed an increase in rCBF in the hippocampus. These results indicate that histamine elicited an increase in rCBF via both H1 and H2 receptors.

Animals↗

PubMed1999

[Gene therapy using anticancer drug-resistance genes].

Myelosuppression is a major dose-limiting factor in cancer chemotherapy. Introduction of drug-resistance genes into bone marrow cells of cancer patients has been proposed to overcome this limitation. In theory, any gene whose expression protects cells against the toxic effects of chemotherapy should be useful in vivo for this purpose. Among such genes, human multidrug-resistance gene (MDR1) has been studied most extensively for this purpose, and clinical trials of drug-resistance gene therapy have been started in the US for cancer patients who undergo high-dose chemotherapy with autologous hematopoietic stem cell transplantation. In Japan, our clinical protocol of MDR1 gene therapy "A clinical study of drug-resistance gene therapy to improve the efficacy and safety of chemotherapy against breast cancer" has been submitted to the government. To improve the efficacy and safety of this drug-resistance gene therapy, we have constructed a series of MDR1-bicistronic retrovirus vectors using a retrovirus backbone of Harvey murine sarcoma virus and internal ribosome entry site (IRES) from picornavirus to co-express a second gene with the MDR1 gene. MDR1-MGMT bicistronic vectors can be used to protect bone marrow cells of cancer patients from combination chemotherapy with MDR1-related anticancer agents and nitrosoureas. In addition, MDR1-bicistronic retrovirus vectors can be designed to use the MDR1 gene as an in vivo selectable marker to enrich the transduced cells which express therapeutic genes, if disease is curable by the expression of a single-peptide gene in any types of bone marrow cells or peripheral blood cells.

Bone Marrow Cells↗

PubMed1999

[Gene therapy using anticancer drug-resistance genes].

Myelosuppression is a major dose-limiting factor in cancer chemotherapy. Introduction of drug-resistance genes into bone marrow cells of cancer patients has been proposed to overcome this limitation. In theory, any gene whose expression protects cells against the toxic effects of chemotherapy should be useful in vivo for this purpose. Among such genes, human multidrug-resistance gene (MDR1) and O6-methylguanine DNA methyltransferase gene (MGMT) have been studied most extensively for this purpose, and clinical trials of drug-resistance gene therapy have been started in the US for cancer patients who undergo high-dose chemotherapy with autologous hematopoietic stem cell transplantation. In Japan, our clinical protocol of MDR1 gene therapy, "A clinical study of drug-resistance gene therapy to improve the efficacy and safety of chemotherapy against breast cancer", has been approved by our IRB and submitted to the government. To improve the efficacy and safety of this drug-resistance gene therapy, we have constructed a series of MDR1-bicistronic retrovirus vectors using a retrovirus backbone of Harvey murine sarcoma virus and internal ribosome entry site (IRES) from picornavirus to coexpress a second gene with the MDR1 gene. MDR1-MGMT bicistronic vectors can be used to protect bone marrow cells of cancer patients from combination chemotherapy with MDR1-related anticancer agents and nitrosoureas. In addition, MDR1-bicistronic retrovirus vectors can be designed to use the MDR1 gene as an in vivo selectable marker to enrich the transduced cells which express therapeutic genes, if disease is curable by the expression of a single-peptide gene in bone marrow cells or any types of peripheral blood cells.

Antineoplastic Agents↗

PubMed1998

Characterization of the LPS-stimulated expression of EP2 and EP4 prostaglandin E receptors in mouse macrophage-like cell line, J774.1.

The expression of prostaglandin (PG) E receptor subtypes were characterized in J774.1, a mouse macrophage-like cell line. EP2- and EP4-mRNAs were found to be expressed. The expression of EP2 mRNA increased by the addition of lipopolysaccharide (LPS) in a dose-dependent manner. EP2 mRNA rapidly increased by more than 5-fold of the control level at 1 h, and decreased after 4 h. EP4 mRNA increased by only 2-fold of the control at 2 h. Gamma interferon inhibited both basal and LPS-induced expression of EP2 mRNA but did not affect the expression level of EP4 mRNA. When tumor necrosis factor-alpha (TNF-alpha) accumulation was measured after the treatment ofthe cells with LPS for 90 min, PGE2 was found to inhibit this accumulation, but butaprost, an EP2-selective agonist, did not. When TNF-alpha release was measured after the treatment of the cells with LPS for 8 h, accumulation was inhibited by butaprost as well as PGE2. These results indicated that the inhibitory effects of PGE2 on TNF-alpha production are mediated by EP2 and EP4 in macrophages, and that expression regulation of EP2 and EP4 in macrophages is quite different.

Alprostadil↗

PubMed1998

p-Chloroamphetamine, a serotonin-releasing drug, elicited in rats a hyperglycemia mediated by the 5-HT1A and 5-HT2B/2C receptors.

The effects of a serotonin (5-HT) releasing drug, p-chloroamphetamine, on plasma glucose levels were investigated in rats. p-Chloroamphetamine elicited a significant hyperglycemia. The hyperglycemic effects of p-chloroamphetamine were completely prevented by the 5-HT synthesis inhibitor, p-chlorophenylalanine. Prior adrenodemedullation abolished the hyperglycemia elicited by p-chloroamphetamine. p-Chloroamphetamine-induced hyperglycemia was prevented by methysergide, which blocks the 5-HT1 and 5-HT2 receptor, the 5-HT1A/1B/2C receptor antagonist, (-)-propranolol, the selective 5-HT1A receptor antagonist, 4-(2'-methoxyphenyl-1-[2'-n-2"pyridinyl)-p-iodobenzamido]-ethyl-pi perazine (p-MPPI), the 5-HT2A/2B/2C receptor antagonists, ritanserin and 4-isopropyl-7-methyl-9-(2-hydroxy-1-methyl-propoxycarbonyl)-4,6A,7 ,8,9,10,10A-octahydro-indolo[4,3-FG]quinolone maleate(LY 53857). However, the 5-HT3 and 5-HT4 receptor antagonist, tropisetron, the 5-HT4 receptor antagonist, 2-methoxy-4-amino-5-chloro-benzoic acid 2-(diethylamino) ethyl ester (SDZ 205-557), and the 5-HT2A receptor antagonist, ketanserin, did not affect the p-chloroamphetamine-induced hyperglycemia. These results suggest that p-chloroamphetamine-induced hyperglycemia is elicited by an enhanced 5-HT release and facilitated adrenaline release. Moreover, our results indicate that p-chloroamphetamine-induced hyperglycemia is mediated by 5-HT1A and 5-HT2B/2C receptors.

4-Aminobenzoic Acid↗

PubMed1998

Effects of the non-selective 5-HT receptor agonist, 5-carboxamidotryptamine, on plasma glucose levels in rats.

The effects of the 5-HT1A/1B/1D/5/7 receptor agonist, 5-carboxamidotryptamine (5-CT), on blood glucose, insulin and glucagon levels in rats were investigated. 5-CT above the dosage of 0.05 mg/kg elicited significant hyperglycemic effects and 0.1 mg/kg, induced a 35% increase in plasma glucose levels. 5-CT did not affect plasma glucagon, and serum insulin levels increased following the high dose of 5-CT. Adrenodemedullation abolished the 5-CT-induced hyperglycemia. Hyperglycemia induced by 5-CT was prevented by pretreatment with the 5-HT1/2/7 receptor antagonist, metergoline, and the 5-HT1/2/5/7 receptor antagonist, methysergide, although the 5-HT2A receptor antagonist, ketanserin, the 5-HT2A/2B/2C receptor antagonist, ritanserin, and the 5-HT3/4 receptor antagonist, tropisetron, had no effect. Although 5-CT has a high affinity with 5-HT1A receptors, the 5-HT1A and 5-HT1B and beta receptor antagonist, (-)-popranolol, did not affect 5-CT-induced hyperglycemia. These results indicate that 5-CT-induced hyperglycemia is elicited by facilitation of adrenaline release from the adrenal gland and that 5-CT-induced hyperglycemia is mediated by the 5-HT7 receptor unrelated to 5-HT1A, 5-HT1B, 5-HT2, 5-HT3, 5-HT4 or 5-HT5 receptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1998

Impaired febrile response in mice lacking the prostaglandin E receptor subtype EP3.

Fever, a hallmark of disease, is elicited by exogenous pyrogens, that is, cellular components, such as lipopolysaccharide (LPS), of infectious organisms, as well as by non-infectious inflammatory insults. Both stimulate the production of cytokines, such as interleukin (IL)-1beta, that act on the brain as endogenous pyrogens. Fever can be suppressed by aspirin-like anti-inflammatory drugs. As these drugs share the ability to inhibit prostaglandin biosynthesis, it is thought that a prostaglandin is important in fever generation. Prostaglandin E2 (PGE2) may be a neural mediator of fever, but this has been much debated. PGE2 acts by interacting with four subtypes of PGE receptor, the EP1, EP2, EP3 and EP4 receptors. Here we generate mice lacking each of these receptors by homologous recombination. Only mice lacking the EP3 receptor fail to show a febrile response to PGE2 and to either IL-1beta or LPS. Our results establish that PGE2 mediates fever generation in response to both exogenous and endogenous pyrogens by acting at the EP3 receptor.

Animals↗

PubMed1998

Stromal and epithelial cells of the canine prostate express parathyroid hormone-related protein, but not the PTH/PTHrP receptor.

BACKGROUND: Parathyroid hormone-related protein (PTHrP), a principal factor in the pathogenesis of humoral hypercalcemia of malignancy, is also widely expressed in many normal tissues, including human prostatic epithelial cells. The role of PTHrP in the prostate is not known, but may include regulation of cell growth and differentiation or calcium secretion into prostatic fluid. The dog is a valuable animal model for human prostatic diseases. The objective was to investigate the expression of PTHrP and the PTH/PTHrP (type 1) receptor in primary cultures of canine stromal and epithelial prostatic cells. METHODS: Expression and secretion of PTHrP and the PTH/PTHrP receptor was measured in homogeneous primary cultures of canine prostatic stromal and epithelial cells using immunohistochemistry, Northern blots, radioimmunoassay, RT-PCR, and receptor stimulation assays. RESULTS: Epithelial and stromal cells expressed and secreted abundant PTHrP, but PTH/PTHrP receptor expression was not detected in either cell type. CONCLUSIONS: PTHrP expression by stromal and epithelial prostatic cells and the absence of the PTH/PTHrP (type I) receptor suggest that some functions previously proposed for PTHrP in the prostate are unlikely. The separation procedure presented is a valuable tool for studying the role and regulation of PTHrP in the prostate.

Animals↗

PubMed1998

Effects of histamine H1 receptor antagonists on compound 48/80-induced scratching behavior in mice.

The effects of histamine H1 receptor antagonists on compound 48/80-induced scratching behavior were studied in mice. Classical histamine H1 receptor antagonists such as diphenhydramine and chlorpheniramine caused a potent depressant effect on compound 48/80-induced scratching behavior. Histamine H1 receptor antagonists having antiallergic activity (an inhibition of mast cell degranulation), such as azelastine and oxatomide and nonsedative histamine H receptor antagonists such as terfenadine, epinastine and astemizole, also showed a relatively potent effect. On the other hand, the effects of tranilast and cromolyn sodium--antiallergic drugs without histamine H1 receptor antagonistic activity--were extremely weak. Diazepam had weak or no depressant effects on compound 48/80-induced scratching behavior. These results suggest that inhibition of compound 48/80-induced scratching behavior is mainly due to histamine H1 receptor antagonistic activity and not to the sedative action of the drugs.

Animals↗

PubMed1998

Efficient protection of cells from the genotoxicity of nitrosoureas by the retrovirus-mediated transfer of human O6-methylguanine-DNA methyltransferase using bicistronic vectors with human multidrug resistance gene 1.

Retrovirus-mediated transfer of O6-methylguanine-DNA methyltransferase (MGMT; E.C. 2.1.1.63) and a human multidrug-resistance gene (MDR1) confers resistance to nitrosoureas and natural product antitumor agents, respectively. In a previous study, we constructed two bicistronic retroviral vectors, Ha-MDR-IRES-MGMT and Ha-MGMT-IRES-MDR, that allow co-expression of the MGMT gene and the MDR1 gene to protect cells from the toxicity of combination chemotherapy. Each cell transduced with Ha-MDR-IRES-MGMT or Ha-MGMT-IRES-MDR showed high-level resistance to vincristine and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosou rea (ACNU), indicating that the two drug-resistance genes can be functionally co-expressed from these vectors. In the present study, we examined whether the expression of MGMT from these MDR1-MGMT bicistronic retroviral vectors could protect cells from the genotoxicity of nitrosoureas. Three independent Ha-MDR-IRES-MGMT-transduced clones and three independent Ha-MGMT-IRES-MDR-transduced clones of HeLa MR cells showed 12-23-fold and 27-30-fold higher MGMT activity than the parental cells. These clones are more resistant to ACNU mutagenicity measured by the frequency of the emergence of 6-thioguanine-resistant colonies after ACNU treatment over the frequency seen in the parental cells. The ACNU-induced sister chromatid exchange (SCE) was markedly suppressed in these clones. Murine bone marrow cells were transduced with either Ha-MDR-IRES-MGMT or Ha-MGMT-IRES-MDR. Non-selected populations of the transduced cells showed only marginal increases in drug resistance and MGMT activity. Remarkable increase in drug resistance and MGMT activity were observed after a short exposure of the transduced cells to vincristine. The Ha-MDR-IRES-MGMT-transduced, vincristine-selected bone marrow cells showed 27-fold resistance to vincristine, 7-fold resistance to ACNU, and 10-fold higher MGMT activity than the non-transduced, non-selected cells. The Ha-MGMT-IRES-MDR-transduced, vincristine-selected cells showed 8-fold resistance to vincristine, 16-fold resistance to ACNU and 19-fold higher MGMT activity than the non-transduced, non-selected cells. The rates of ACNU-induced SCE in the vincristine-selected cells were as follows: non-transduced cells (non-selected) and HaMDR-transduced cells>Ha-MDR-IRES-MGMT-transduced cells>Ha-MGMT-IRES-MDR-transduced cells. Again, the only marginal levels of increases in the rates of ACNU-induced SCE were observed in non-selected population of the transduced cells. These results indicate that the MDR1-MGMT bicistronic retrovirus vectors would be useful to protect normal hematopoietic cells from nitrosourea-induced mutagenesis, and drug-selectable bicistronic constructs would have great advantage over non-selectable vectors.

Animals↗

PubMed1998

Effects of adrenalectomy on hyperphagia induced by the 5-HT1A receptor agonist 8-OH-DPAT and 2-deoxy-D-glucose in rats.

Effects of adrenalectomy on the 5-HT1A receptor agonist 8-hydroxy-2-di-n-(propylamino)tetralin (8-OH-DPAT)- and 2-deoxy-D-glucose (2-DG)-induced hyperphagia were investigated in rats. Prior adrenalectomy completely inhibited 2-DG-induced hyperphagia, although it did not affect increases in food intake elicited by 8-OH-DPAT. These results suggest that 8-OH-DPAT-induced hyperphagia is independent of the adrenal hormone, corticosterone while 2-DG-induced hyperphagia is closely related to corticosterone.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1998

Patent ductus arteriosus and neonatal death in prostaglandin receptor EP4-deficient mice.

The physiological role of the prostaglandin E2 receptor EP4 subtype was investigated by generation of EP4-deficient-mice by gene targeting. Loss of the EP4 receptor was not lethal in utero, but most EP4 (-/-) neonates became pale and lethargic approximately 24 h after birth and died within 72 h. Less than 5% of the EP4 (-/-) mice survived and grew normally more than a year. Histological examination revealed that the ductus arteriosus in dead neonates remained open, while it was partially closed in the survivors. In situ hybridization study showed that EP4 mRNA was strongly expressed in the ductus. These results suggest that neonatal death is at least partly due to patent ductus arteriosus and that the EP4 receptor plays a role in regulation of the patency of this vessel. They also indicate that normal function of the EP4 receptor is essential in neonatal adaptation of the circulatory system.

Animals↗

PubMed1998

High-Resolution X-ray Diffraction of Muscle Using Undulator Radiation from the Tristan Main Ring at KEK.

High Energy Accelerator Research Organization (KEK), Tsukuba, Japan.High-resolution X-ray diffraction studies on striated muscle fibres were performed using a hard X-ray undulator installed in the Tristan main ring at KEK, Tsukuba, Japan. The performance of the undulator, along with an example experiment which exploited the unique characteristics of undulator radiation, are reported. The vertical divergence angle of the first harmonic of the undulator was approximately 10 micro rad under 8 GeV multi-bunch operating conditions and the peak photon flux density was estimated to be approximately 3 x 10(16) photons s(-1) mrad(-2) (0.1% bandwidth)(-1) (10 mA)(-1). The well collimated X-ray beam from the undulator made it possible to resolve clearly, with high angular resolution ( approximately 700 nm), the closely spaced diffraction peaks on the meridional axis in the X-ray patterns arising from the thick filaments of a striated muscle under static conditions. By fitting the meridional intensity pattern, a model for the molecular arrangement of the constituent proteins in the thick filaments is proposed. These studies of muscle demonstrate the promise of undulator radiation from third-generation sources for high-resolution diffraction studies.

Journal Article↗

PubMed1998

Characterization of the gene for the mouse prostaglandin E receptor subtype EP2: tissue-specific initiation of transcription in the macrophage and the uterus.

Genomic DNA clones for the mouse prostaglandin (PG) E receptor subtype EP2 were isolated and characterized. The mouse EP2 gene is composed of 2 exons and 1 intron, and spans 16 kb. The intron which is approx. 12 kb in length is located at the end of the sixth transmembrane domain, as with other prostanoid receptor genes. Based on this structure, transcripts were analysed in endotoxin-treated macrophages and pseudopregnant uteri, in which abundant expression of EP2 mRNA was observed. Sequence analysis of cDNA clones from these origins and Northern hybridization of these RNAs revealed that the uterine EP2 mRNA (U-type) has a longer 5'-untranslated region than the macrophage EP2 transcript (M-type). The major transcription initiation sites for M-type and U-type EP2 are located 124 and 769 bp upstream of the translation start site, respectively. The M-type was expressed in various tissues, whereas the U-type was found only in the uterus. The 2 kb segment containing the immediate 5'-flanking and 5'-noncoding regions contain three consensus sequences for the NF-IL6 binding site, one consensus sequence for the NF-kappaB binding site, four AP-2 consensus sequences, one AP-4 consensus sequence, one potential cAMP response element, and one potential progesterone response element. These results suggest that EP2 gene expression in the macrophage and uterus is under the control of distinct mechanisms involving alternative promoters.

Amino Acid Sequence↗

PubMed1998

Identification of a distinct antibacterial domain within the N-lobe of ovotransferrin.

We have evaluated the bactericidal activity of hen ovotransferrin (OTf), which was found to operate regardless of its iron-deprivation properties, with the objective of isolating the bactericidal domain. The amino-terminal half-molecule (N-lobe, residues 1-332) of OTf, isolated by trypsin-nicking, retained the bactericidal activity independently of iron-deprivation, but not the carboxyl-terminal half-molecule (C-lobe, residue 342-686), suggesting the presence of a bactericidal domain within the N-lobe of the molecule. Specific cleavage at the aspartyl residues of OTf, by diluted-acid procedure, yielded fairly large peptides, whereas proteolysis for 150 min produced the strongest bactericidal peptides mixture. The bactericidal domain was purified from the active hydrolysate by gel filtration and reversed-phase HPLC and showed activity against S. aureus as well as E. coli K-12. Electrophoretic analysis on tricine-SDS-PAGE revealed a bactericidal peptide with an average M(r) of 9900 Da under non-reducing conditions. In combination with the specificity of cleavage (Asp-X) and the molecular mass, its N-terminal microsequencing corresponded to a cationic peptide consisting of 92 residues located within the 109-200 sequence of the N-lobe of OTf, containing three intrachain disulfide bridges, featuring a common structural motif occurs in the N-lobes of transferrins for which the sequence is available. Two of the disulfides (C160-C174 and C171-C182) form surface exposed cringle bridges lying on the opposite side of the iron-binding site from the interdomain cleft and showing marked sequence homology to insect defensins, which are blockers of the voltage-dependent K+ channels. The peptide lost antibacterial activity when its disulfide bonds were reduced, indicating the importance of its tertiary structure for the exertion of antibiotic activity.

Amino Acid Sequence↗

PubMed1998

Carbohydrate malabsorption following acarbose administration.

Carbohydrate absorption was assessed during acarbose administration to investigate the actions of this drug. In 7 healthy volunteers, breath hydrogen concentration was measured at 15-min intervals after administration of 6 g of lactulose, and continued until 4 h after the breath hydrogen level exceeded its pretreatment value by > or =10 ppm, then the amount of undigested carbohydrate was calculated following administration of various doses of acarbose and Ensure Liquid. Breath hydrogen data were also obtained before and after administration of acarbose to 8 patients with Type 2 diabetes mellitus for 2 and 4 months. After administration of 50 mg of acarbose with 250 ml or 500 ml of Ensure, the mean amount of unabsorbed carbohydrate was 5.3 g and 7.7 g, respectively, while unabsorbed carbohydrate increased to 10.8 g after 100 mg of acarbose with 500 ml of Ensure. In the diabetic patients, breath hydrogen excretion decreased to 31.6% of baseline after 2 months of acarbose administration, indicating decreased carbohydrate malabsorption. Despite this, the haemoglobin A1c level remained stable after 5 months. In conclusion, the extent of carbohydrate malabsorption depended on the acarbose dose and the carbohydrate load. Although carbohydrate malabsorption decreased with continued acarbose administration, the improvement of glycaemic control was maintained.

Acarbose↗

PubMed1998

Female reproduction in mice lacking the prostaglandin F receptor. Roles of prostaglandin and oxytocin receptors in parturition.

Female mice lacking the receptor for prostaglandin F2 alpha (FP) do not deliver fetuses at term, although these can be successfully rescued by cesarean section. No induction of oxytocin receptor mRNA is found in the uterus of these mice, and they show no uterine contraction on intravenous administration of oxytocin. Furthermore, a decline in serum progesterone levels during the periparturition period is not observed in these animals. Ovariectomy at day 19 of pregnancy restored induction of the oxytocin receptor and caused successful delivery in these animals. These results indicate not only the essential role of luteolytic PGF 2 alpha action in natural parturition but also the importance of oxytocin receptor induction in this process.

Animals↗