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Biomedical subjects

T Doi

Publications and source records attributed to T Doi.

At least 235 records · Page 13Linked to original sources
PubMed1996

[Isoflurane and sevoflurane impair left ventricular relaxation in dogs with fixed heart rate].

The effects of isoflurane (Iso) and sevoflurane (Sev) on left ventricular relaxation were evaluated in 22 open-chest dogs with fixed heart rate (130 beats.min-1) using atrial pacing. Fentanyl was injected intravenously to maintain anesthesia during the preliminary preparation. In both Iso and Sev groups (n = 11), left ventricular systolic pressure, mean aortic pressure and dp/dt max were significantly decreased at 0.5 MAC, but there was no significant change in left ventricular end-diastolic pressure. Left ventricular systolic function was depressed to the similar extent in both groups. In Sev group, -dp/dt max and time constant of isovolumic left ventricular pressure fall (T) increased significantly at 0.5 MAC but it increased at 1.5 MAC in Iso group. T at 0.5 MAC Sev was also significantly longer compared with T at equipotent Iso. These findings suggest that Sev may impair isovolumic left ventricular relaxation more strongly than Iso, and this may result from the difference of the effect of each agent on intracellular Ca2+ homeostasis in the myocardium.

Anesthetics, Inhalation↗
PubMed1996

Intercellular adhesion molecule-1 release from human hepatocellular carcinoma.

Serum levels of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were measured in 38 patients with chronic hepatitis (CH), 29 with liver cirrhosis (LC), and 43 with hepatocellular carcinoma (HCC) using enzyme-linked immunosorbent assays. All the patients showed significantly higher serum levels of these circulating adhesion molecules than 40 normal controls. The serum E-selectin level showed no relationship to the levels of the other adhesion molecules. Serum VCAM-1 levels were well correlated with serum ICAM-1 levels in CH and LC patients. In HCC patients, however, the close correlation between VCAM-1 and ICAM-1 was lost, because the patients with large tumors (100 cm2) showed relatively high ICAM-1 levels. The amount of ICAM-1 shed from the tumor cells was calculated in the HCC patients as follows: actual serum ICAM-1 level minus basal ICAM-1 level released from the noncancerous liver (obtained from the regression line between ICAM-1 and VCAM-1 in CH and LC patients). Although there was no relationship between the actual ICAM-1 level and the tumor size in HCC patients, the predicted ICAM-1 shedding was closely correlated with tumor size. When in situ expression of these adhesion molecules was evaluated in 10 HCC tissues using immunohistochemistry, the tumor cells exhibited enhanced ICAM-1 expression but did not express E-selectin and VCAM-1. These results suggest that the elevated serum levels of adhesion molecules in HCC patients are mainly attributable to the associated liver inflammation, although some ICAM-1 is shed into the circulation by tumor cells.

Carcinoma, Hepatocellular↗
PubMed1996

[CD7, HLA-DR, CD38 positive acute undifferentiated leukemia with subcutaneous tumor and thymoma].

A case of acute undifferentiated leukemia (AUL), accompanied by subcutaneous tumor and thymoma is reported. The analysis of immunophenotype showed that the leukemic blasts were positive for CD7, HLA-DR, CD38 and CD34 in 17.5% but negative results were obtained for other lymphoid and myeloid antigens. The leukemic blasts had a rearranged immunoglobulin heavy chain (IgH) gene and T cell receptor delta (TCR-delta) chain gene chromosomal abnormality, 47, XY, +8, t(13; 17) (q12; q21), -17, +M was observed. In general, the CR rate is low and prognosis is poor in patients with AUL. In our case, CR was not achieved by the therapy with JALSG-ALL87 protocol, but was achieved by subsequent treatment with high dose ara-C therapy and combination chemotherapy including intermediate-dose ara-C, mitoxantrone, etoposide and prednisolone.

ADP-ribosyl Cyclase↗
PubMed1996

[Molecular approach to detection of micrometastatic prostatic cancer cells in the lymph nodes and the bone marrow].

We detected micrometastatic prostate cancer cells in lymph nodes and bone marrow using reverse transcriptase-polymerase chain reaction (RT-PCT) specific for prostate-specific antigen (PSA). RT-PCR revealed PSA mRNA in two lymph nodes obtained from two patients with negative histological and immunohistochemical analyses for lymph node metastases. Of 26 patients with negative bone scan imaging, 7 had PSA mRNA detected in the bone marrow by RT-PCR. The RT-PCR will be a relevant tool to allow a more accurate clinical assessment of lymph node and bone metastases in patients with prostate cancer.

Bone Marrow Neoplasms↗
PubMed1996

[Effect of macrophage colony-stimulating factor on complement receptors and complement regulatory proteins on human peripheral white blood cells].

The effect of M-CSF and C5a on the expression of complement-related membrane proteins on the peripheral white blood cells was investigated. M-CSF or C5a was added into the suspension of the peripheral white blood cells. The expression of the complement receptors, CD35 (CR1) and CD11b/18 (CR3), and inhibitory membrane proteins, DAF and MCP, was measured by flow cytometry. M-CSF increased CR3 on polymorphonuclear cells (PMNs) and CR1, CR3, MCP and DAF on monocytes. C5a increased CR1, CR3 and DAF on PMNs, but did not affect the expression of those on monocytes. It is concluded that M-CSF possessed the activity of increase expression of both complement regulatory proteins and complement receptors of monocytes and C5a selectively affected the expression of those on PMNs.

Adult↗
PubMed1995

Subunit-specific inhibition of inward-rectifier K+ channels by quinidine.

Distinct inward-rectifier K+ channel subunits were expressed in Xenopus oocytes and tested for their sensitivity to the channel blocker quinidine. The 'strong' inward-rectifier K+ channel IRK1 was inhibited by quinidine with an EC50 of 0.7 mM, while the 'weak' rectifier channel ROMK1 was only moderately inhibited. ROMK1(N171D)-IRK1C-term chimeric channels, which carry both sites for strong rectification of IRK1 channels (the negatively charged D171 in the second transmembrane domain and the IRK1-C-terminus including E224), displayed strong rectification like IRK1, but showed weak sensitivity to quinidine-like ROMK1, suggesting independence of quinidine binding and rectification mechanisms. Moreover, BIR10 and BIR11, two strong rectifier subunits originally cloned from rat brain, exerted subunit-specific sensitivity to quinidine, being much higher for BIR11. Quinidine blockade of IRK1 was not voltage-dependent, but strongly dependent on the pH in the superfusate. These results strongly suggest a subunit-specific interaction of inward-rectifier K+ channels with neutral quinidine within membrane lipid bilayers.

Animals↗
PubMed1995

Novel, potent, and orally active substance P antagonists: synthesis and antagonist activity of N-benzylcarboxamide derivatives of pyrido[3,4-b]pyridine.

A series of 4-phenylisoquinolone derivatives were synthesized and evaluated for NK1 (substance P) antagonist activity. Highly potent antagonists, 4-phenyl-3-isoquinolone-N-benzylcarboxamides (11), were discovered from the structure-activity relationship studies on the isoquinolone-urea lead 1a. Optimization of the activity in this series resulted in the development of 5-phenyl-6-pyrido[3,4-b]pyridine-N-benzylcarboxamides (30) which are highly potent orally active NK1 antagonists. Among the compounds synthesized, N-[3,5-bis(trifluoromethyl)benzyl]-7,8-dihydro-N,7-dimethyl-8-oxo-5- (substituted phenyl)-6-pyrido[3,4-b]pyridinecarboxamides (30a,f,g) showed excellent antagonist activities with IC50 values (in vitro inhibition of [125I]-BH-SP binding in human IM-9 cells) of 0.21-0.34 nM and ED50 values (in vivo inhibition of capsaicin-induced plasma extravasation in guinea-pig trachea, iv) of 0.017-0.030 mg/kg. These compounds exhibited significantly potent activity upon oral administration with ED50 values of 0.068-0.17 mg/kg. Conformational studies on 30g indicated that the two stable conformers of 30g are quite similar to those of CP-99,994.

Administration, Oral↗
PubMed1995

alpha-amylase inhibitor increases plasma 3-hydroxybutyric acid in food-restricted rats.

The effect on energy metabolism of delayed absorption of starch by inhibition of alpha-amylase was examined by considering levels of plasma glucose and 3-hydroxybutyric acid (3-OHBA) in rats. Addition of alpha-amylase inhibitor (alpha AI) to a high starch diet delayed the plasma glucose response after feeding: peak plasma glucose levels in the control group occurred 15 min after feeding, whereas in the alpha AI group this peak did not occur until 30 min after. The total plasma glucose response was not different between the two groups. Plasma 3-OHBA levels 1 day after food restriction increased approximately five-fold in both groups. After 3 days of food restriction, the alpha AI group maintained the same level of plasma 3-OHBA as after 1 day of food restriction, while the control group showed significantly decreased levels of 3-OHBA. After 3 days of food restriction, plasma insulin levels were significantly decreased in the alpha AI group compared with the corresponding levels of the control group and with levels before the restriction. There was no significant difference in body weight between the two groups. These findings suggest that delayed hyperglycemia due to delayed absorption of starch following alpha AI loading may attenuate insulin secretion, leading to altered metabolism of 3-OHBA during the delayed response to energy deficit.

3-Hydroxybutyric Acid↗
PubMed1995

Induction of teratocarcinoma F9 cell differentiation with cis-diammine dichloroplatinum(II) (CDDP).

cis-Diammine dichloroplatinum(II) (CDDP) is the salt of a platinum compound which has been noted to have a wide spectrum of activity against malignant disorders. We have studied the effects of CDDP on embryonal carcinoma F9 cell differentiation. In the presence of this agent in vitro, the cells showed rapid morphological changes, a marked increase in the mRNA expression of various differentiation markers accompanied by a loss of tumorigenicity. These results indicate that the differentiation of F9 cells is induced with CDDP.

Animals↗
PubMed1995

Plasma concentrations and coronary vasodilation after sublingual and intracoronary administration of isosorbide dinitrate.

To investigate the relationship between plasma levels and coronary vasodilation after administration of isosorbide dinitrate (ISDN), the plasma concentration and diameters of six segments of the left coronary artery were measured before and after sublingual (SL) ISDN (5 mg) and left intracoronary (IC) administration of ISDN (3 mg) in 12 patients. After SL-ISDN, the systolic aortic pressure decreased with no significant concomitant changes in heart rate or diastolic aortic pressure. After IC-ISDN, all hemodynamic parameters showed significant changes, and these were greater after IC-ISDN than those after SL-ISDN. The individual mean vasodilation of six segments induced by SL- and IC-ISDN, were 23 +/- 9 and 35 +/- 11% (p < 0.01), respectively. Before SL-ISDN, ISDN was not detected in plasma. After SL- and IC-ISDN, however, the plasma values of the ISDN were 36.1 +/- 53.3 and 101.5 +/- 90.0 ng/ml (p < 0.01), respectively. Thus, both coronary vasodilative responses and plasma ISDN levels after IC-ISDN were significantly greater than those after SL-ISDN. However, neither the individual mean coronary vasodilation nor the hemodynamic changes correlated significantly with plasma ISDN levels. Consequently, with administration of the same dose, the coronary vasodilative response to ISDN did not correlate with plasma levels. Furthermore, IC-ISDN dilutes coronary arteries more effectively than SL-ISDN.

Administration, Sublingual↗
PubMed1995

Sensitive detection and structural characterization of trimethyl(p-aminophenyl)-ammonium-derivatized oligosaccharides by electrospray ionization-mass spectrometry and tandem mass spectrometry.

Mass spectrometric methodologies which use electrospray ionization (ESI) for oligosaccharide structural determination and which are linked to classical procedures, such as reductive amination, have been established. Several derivatives of a model oligosaccharide were prepared and their ionization efficiencies in electrospray ionization (ESI) and fast-atom bombardment (FAB) mass spectrometry were investigated. The trimethyl-(p-aminophenyl)ammonium (TMAPA) derivatives showed extremely high sensitivity in positive-ion ESI-MS and gave Y- and Z-series sequence ions by ESI tandem mass spectromety (MS/MS). This study suggests that TMAPA-derivatized oligosaccharides used in ESI-MS and ESI-MS/MS would be effective for structural characterization of oligosaccharides that are available only in limited quantities.

Aminopyridines↗
PubMed1995

Hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle.

We describe a family line with an autosomal recessive disease of muscular dystrophy of the diaphragmatic muscles in Holstein-Friesian cattle. Histopathological examination in the present cases revealed various degenerative changes in the diaphragmatic and other thoracic muscles as follows: variation in muscle fiber diameter, fiber splitting, sarcoplasmic masses, ring fiber, vacuolar and hyalinized degeneration of muscle fibers. In addition, central core-like structures were the prominent features in the diaphragmatic muscles, occupying the center of the fiber or scattered within the fiber. These pathological alterations are consistent with the diaphragmatic myopathy previously reported in Meuse-Rhine-Yssel cattle in the Netherlands. The fibers containing core-like structures consisted of three distinct zones which could be well distinguished by NADH-tetrazolium reductase activity. This activity was absent in the innermost zone, decreased in the intermediate zone, and normal or increased in the periphery. Electron microscopically, this structure appeared to be composed of focal myofibrillar degeneration beginning with streaming or disintegration of the Z disk. We discuss here the similarity between this core-like structure and the other alternative organelles that have been reported previously, and a possible defect or storage in the cytoskeleton from the findings of the Z disk abnormalities.

Animals↗
PubMed1995

The kinetics of induction of Hox1.6 and C-jun mRNA during three different ways of inducing differentiation in teratocarcinoma F9 cells.

Changes in Hox1.6 and c-jun gene expression were examined upon F9 cell differentiation that was induced by three independent methods: a drug treatment with retinoic acid (RA), that with sodium butyrate (NaB), and a genetic approach using the ts mutant. To obtain further information on the mechanism of teratocarcinoma cell differentiation we have examined the kinetics of the induction of Hox1.6 and c-jun mRNA whose gene products have been demonstrated to have specific roles in gene regulation. Expression of Hox1.6 mRNA was induced more rapidly than c-jun mRNA by all the above three inducing methods. Furthermore, protein synthesis was not required for the induction of Hox1.6 mRNA as well as of c-jun mRNA synthesis in all three methods. The data suggested that the transcriptional increase in the Hox1.6 mRNA was a primary response and could play an important role in F9 cell differentiation.

Butyrates↗
PubMed1995

Cloning and expression of laminin alpha 2 chain (M-chain) in the mouse.

Laminins are a family of heterotrimeric glycoproteins specific to basement membranes. Laminin-2, consisting of alpha 2, beta 1 and gamma 1 chains, was originally identified in the basement membranes of skeletal muscle and peripheral nerve. We have isolated and sequenced the full-length cDNA for the mouse laminin alpha 2 chain. Four overlapping clones spanning 9,330 bp encode a predicted polypeptide of 3,106 amino acids having a calculated molecular mass of 390 kDa including a 23-amino-acid signal peptide. The amino acid sequence of the alpha 2 chain shares a 45.9% identify with that of the alpha 1 chain. Similar to the structure of the alpha 1 chain, the alpha 2 chain consists of several domains beginning at the N-terminus with three globular domains alternating with three epidermal growth factor-like domains followed by two alpha-helical domains and a C-terminal globular domain. The most N-terminal globular domain is highly conserved (77.3% identity) between the alpha 2 and alpha 1 chains, whereas the alpha-helical domains have low homology (30.3% identity). Northern blot and ribonuclease protection analysis revealed expression of mRNA for the alpha 2 chain in heart, kidney, liver, skin, lung and skeletal muscle of newborn mice. such a tissue distribution suggests a role for the alpha 2 chain and, consequently, laminin-2 or -4 not only in the organization and the function of nerve and muscle tissue but possibly also in the mesenchymal components of certain tissues.

Amino Acid Sequence↗
PubMed1995

Expression of tenascin in odontogenic tumours.

We investigated the expression of tenascin in a series of odontogenic tumours (n = 63) of epithelial and epithelial-ectomesenchymal origin by using immunohistochemical methods. A heterogeneity of expression of tenascin was observed in odontogenic tumours. The heterogeneity was most prominent in odontogenic tumours not forming calcified tissues. In these ameloblastomas and adenomatoid odontogenic tumours, tenascin was mainly localised at the epithelial tumour cell-mesenchymal tissue interface. In the calcifying epithelial odontogenic tumour, ameloblastic fibroma and odontoma, a widespread stromal immunoreactivity was observed which was, however, unreactive in the calcified masses. The stellate reticulum-like cells and granular cells of ameloblastoma also showed a positive immunoreactivity for tenascin. The results of the present study suggest that expression of tenascin in the stromal tissue of odontogenic tumours differs according to the potential of forming calcified masses by the tumour cells irrespective of tumour cell morphology.

Ameloblastoma↗