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Biomedical subjects

M Azuma

Publications and source records attributed to M Azuma.

At least 343 records · Page 19Linked to original sources
PubMed1990

[Estimation of portosystemic shunt by transrectally administered 123I-IMP].

Portosystemic shunt index was estimated in 7 patients without liver disease and 95 patients with various liver diseases by portal scintigraphy with transrectally administered 123I-iodoamphetamine (IMP). The shunt index was 0% in patients without liver diseases, 5.3% in acute hepatitis, 5.9% in chronic inactive hepatitis, 11.4% in chronic active hepatitis, 56.6% in compensated liver cirrhosis and 88.1% in decompensated liver cirrhosis. The shunt index was significantly higher in liver cirrhosis, especially decompensated stage. In 5 of 9 patients with acute hepatitis, shunt index was 0%. In 3 of remaining 4 patients with elevated shunt index, shunt index became 0% within 1-2 months. Significant relationship was observed between the shunt index and hepatic function tests such as ChE, albumin, gamma-globulin and ICG-R15. These results suggest that the shunt index is independent of hepatic cell necrosis and reveals the shunted blood flow exactly. Therefore, this technique is useful for evaluating the portosystemic shunt in various liver diseases.

Administration, Rectal↗
PubMed1990

Genetically defined membrane-bound and soluble alkaline phosphatases of the silkworm: their discrete localization and properties.

In the midgut tissue of the silkworm, Bombyx mori, alkaline phosphatase isozymes, membrane-bound (m-ALP) and soluble (s-ALP) forms are controlled by non-allelic genes on the same chromosome. We purified and characterized both ALPs to elucidate their possible functions and to compare with mammalian ALPs. Both forms were found to be similar Mr = 68,000 in gel permeation chromatography and as a single subunit as a monomer in SDS-polyacrylamide gel electrophoresis with Mr = 58,000 for m-ALP and Mr = 61,000 for s-ALP. The pH optima of ALPs were 10.9 (m-ALP) and 9.8 (s-ALP), and the former was extremely stable even in pH 10-12 which accords with the physiological milieu in Bombyx midgut lumen. Both ALPs had similar substrate specificities. L-cysteine inhibited strongly both ALPs, but inhibitory effects of L-phenylalanine, L-homoarginine, and L-leucine were undetectable for s-ALP and very weak for m-ALP. The antibody raised against purified m-ALP recognized m-ALP but not purified s-ALP and vice versa. Rocket-immunoassay showed that m-ALP was distributed in similar levels along the length of midgut except for the most anterior portion. Seventy percent of s-ALP activity existed in the last one-third of midgut. Immunohistochemical study revealed that the m-ALP was localized at the brush border of columnar cells in the middle and posterior midgut epithelia. In contrast, the s-ALP was localized at the apical surface of goblet cells through the length of midgut. We detected ATPase activity in the purified s-ALP preparation; Mg2+ was essential for the ATPase activity and the activity also increased with KHCO3 but not with KCl. The solubilization test of m- ALP with various agents was attempted and the relationship between m-ALP and the digestive fluid-ALP was discussed.

Alkaline Phosphatase↗
PubMed1989

Expression of neurofilaments in a neoplastic human salivary intercalated duct cell line or its derivatives and effect of nerve growth factor on the cellular proliferation and phenotype.

A neoplastic salivary cell line with an ultrastructure similar to that of an intercalated duct cell of the salivary gland, established from a human submandibular salivary gland, has been used in our laboratory as a model for studying mechanisms regulating cytodifferentiation in salivary glands. The expression of neurofilaments (Mr 200,000, 160,000, and 68,000) in the neoplastic human salivary intercalated duct cell line and its derivatives was found by the immunofluorescence staining technique, immunoblotting, or immunoelectron microscopy. In addition, these cells stained with Bodian impregnation and expressed specific antigens such as tubulin alpha and beta chain, HNK-1 antigen, and laminin. When these cells were cultured in the presence of nerve growth factor, only the cells with a myoepithelial cell phenotype formed the long cytoplasmic processes which were densely packed with ample microfibrils in addition to microtubule bundles, and they exhibited marked suppression of anchorage-independent and anchorage-dependent growths. These findings indicate that the characteristics of neoplastic human salivary intercalated duct cell line and its derivatives are similar to those of neuronal cells.

Biomarkers↗
PubMed1989

Induction of cells with a chondrocyte-like phenotype by treatment with 1 alpha,25-dihydroxyvitamin D3 in a human salivary acinar cell line.

A clonal cell with an acinar cell phenotype, which was induced by 5-azacytidine treatment of a neoplastic human salivary intercalated duct cell line, was cultivated in the presence of 1 alpha,25-dihydroxyvitamin D3. Morphological changes occurred; large cells that were polygonal or round in shape and had numerous vacuoles in their cytoplasm appeared in the treated cells, whereas the same concentration of 1 alpha,25-dihydroxyvitamin D3 did not affect the morphology of the parental cells. Major alterations, such as expression of type II collagen, alpha and beta chains of S-100 protein, and sulfated proteoglycans, were observed in these cells with a phenotype similar to chondrocytes. After the removal of 1 alpha,25-dihydroxyvitamin D3 from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that the reversible differentiation into chondrocyte-like cells of a human salivary acinar cell line occurs in growth medium containing 1 alpha,25-dihydroxyvitamin D3.

Calcitriol↗
PubMed1989

[Evaluation of changes in portal collaterals by single photon emission CT: effects of endoscopic injection sclerotherapy].

The changes in portal collaterals before and after Endoscopic Injection Sclerotherapy (EIS) for esophageal varices were studied by Single Photon Emission CT (SPECT). SPECT was performed for the intra-abdominal blood pool with 99mTc autologous red blood cells (RBC) in 17 patients with liver cirrhosis before and after EIS. Twenty mCi of 99mTc-RBC labeled by in vivo technique were administered intra-venously and tomographic imaging of the intra-abdominal vascular blood pool was performed as follows. For each subjects, 64 views were obtained over 360 degrees of elliptic rotation at 30 seconds per view. In 15 of 17 patients, blood pool images over coronary vein and/or short gastric vein area were clearly demonstrated on coronary images. In 9 of 15 patients, the pool of coronary vein or short gastric vein was disappeared or decreased after EIS. It is considered that intra-abdominal blood pool SPECT study is clinically useful for following up of hemodynamics of portal collaterals before and after EIS.

Adult↗
PubMed1989

[The influence of endotracheal tube size on the airway flow resistance and work in infants analyzed using a simulation technique].

The respiratory flow velocity of 74 infants under halothane-nitrous oxide-oxygen anesthesia was measured, and the statistical relationship between the age in months and the flow velocity was obtained with least square method. The flow resistance of endotracheal tubes (size of 2.5, 3.0, 3.5, 4.0, 4.5 and 5.0 mmI.D.) with the flow velocity below 45 ml.sec-1 was also measured in in vitro experiments. The standard respiratory flow velocity of 6, 12, 24, 36, 48 and 60 month old infants was estimated by the recurrent formula. The mean flow resistance and respiratory work with each size of endotracheal tube were calculated by simulation technique using these data. These data coincided well with the data obtained by calculation based on in vitro experiments.

Aging↗
PubMed1989

Effects of halothane and enflurane on conduction velocity and maximum rate of rise of action potential upstroke in guinea pig papillary muscles.

Using standard microelectrode techniques, the effects of halothane and enflurane on the maximum rate of rise of action potential upstroke (Vmax) and conduction velocity of excitation were compared with those of fast sodium channel blockers in isolated guinea pig papillary muscles. Lidocaine and tetrodotoxin decreased the square of the conduction velocity in proportion to the decrease in Vmax. In contrast, halothane and enflurane only slightly affected Vmax, but decreased the conduction velocity in a concentration-dependent manner. These results suggest that these volatile anesthetics affect conduction velocity by a mechanism different from that of fast sodium channel blockers. Caution should be used when these anesthetics are administered to patients receiving class 1 antiarrhythmic agents or who have pre-existing intraventricular conduction disease.

Action Potentials↗
PubMed1988

Effects of retinoic acid on morphological features and biological markers of a neoplastic human salivary intercalated duct cell line in culture.

Retinoic acid has marked effects on the growth, morphological features, and biological markers of a neoplastic human salivary intercalated duct cell clone in culture, whereas the cell clone was not affected by other retinoids such as retinol and retinal. A cell clone with ultrastructure and biological markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of retinoic acid. Major alterations, such as expression of tonofilaments, Mr 68,000 cytokeratin, and involucrin, were observed in those cells with a phenotype similar to that of keratinizing squamous cells. In addition, the coexpression of Mr 68,000 cytokeratin and carcinoembryonic antigen in these altered cells was found. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of retinoic acid. After the removal of retinoic acid from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the keratinizing squamous cells of a neoplastic human salivary intercalated duct cell clone occurs in growth medium containing retinoic acid.

Adenocarcinoma↗
PubMed1988

Cellular proliferation and ras oncogene of p21 21,000 expression in relation to the intracellular cyclic adenosine 3':5'-monophosphate levels of a human salivary gland adenocarcinoma cell line in culture.

We have found that reversible differentiation into the myoepithelial cells of a human salivary gland adenocarcinoma cell line (HSG) occurs in growth medium containing dibutyryl cAMP (dB-cAMP). In the current study, the relationship between intracellular cAMP levels and anchorage-dependent and -independent growth or ras oncogene of p21 levels was analyzed in the differentiation process toward myoepithelial cells of HSG cells cultured in the presence of dB-cAMP. Correlation between the concentrations of dB-cAMP and intracellular cAMP in the HSG cells was statistically significant. There was a significant inverse correlation between the concentrations of dB-cAMP and colony-forming ability of the cells in semisolid agar or on a plastic surface. We have found the expression of ras p21 protein in HSG cells. When HSG cells were cultured in the presence of dB-cAMP and were committed to differentiate into myoepithelial cells, it was shown by double-antibody labeling technique and/or immunoblotting that the committed cells expressed myosin with a concomitant decrease of ras p21 protein. Moreover, intracellular cAMP levels were found to be inversely associated with ras p21 content of the cells. These findings indicate that the intracellular cAMP levels regulate significantly cell proliferation and ras p21 expression in HSG cells.

Adenocarcinoma↗
PubMed1988

Enhancement of cis-diamminedichloroplatinum and mitomycin C-induced sister chromatid exchanges by dibutyryl cyclic AMP in a human salivary gland adenocarcinoma cell line in culture.

A human salivary gland adenocarcinoma cell line was cultivated in the presence of dibutyryl cyclic AMP (dB-cAMP), cis-diammine dichloroplatinum (cisplatin) or mitomycin C (MMC) only, or of the combination of dB-cAMP and each of the antineoplastic drugs. Then the treated cells were examined for the induction of sister chromatid exchanges (SCEs), colony-forming efficiency (CFE) in semisolid agar medium and cell survival as measured by counting for viable cells. It has been found that the frequency of SCE induction is significantly increased by treatment of cells with cisplatin or MMC under the presence of dB-cAMP, when compared to that in the cells treated with cisplatin or MMC only. Moreover, marked reduction in CFE and cell survival was found to occur in the cells treated with the combination of dB-cAMP and cisplatin or MMC. These finding indicate that treatment of a human salivary gland adenocarcinoma cell line with dB-cAMP results in modification of SCE induction, CFE and cell survival in the cells exposed to cisplatin or MMC.

Adenocarcinoma↗
PubMed1988

Formation of visual pigment chromophores during the development of Xenopus laevis.

Retinoids in the eyes of Xenopus laevis at several developmental stages, were analyzed by high-performance liquid chromatography (HPLC). At stage 37/38, larval eyes contained mainly all-trans isomers of retinal, 3-dehydroretinal, retinyl ester and 3-dehydroretinyl ester. Ratios of all-trans 3-dehydroretinal to retinal and of all-trans 3-dehydroretinyl ester to retinyl ester were almost 1 at the stage. With the advance of development, the amounts of all-trans retinal and 3-dehydroretinal decreased; however, those of all-trans retinyl ester and 3-dehydroretinyl ester increased. The chromophores of visual pigments, 11-cis retinal and 3-dehydroretinal, were detected at stage 40 (total; 0.2 pmol/eye) and their amounts increased after that stage. The ratio of 11-cis 3-dehydroretinal to retinal was almost 1 at stages 40-42. The ratio became larger after stage 43 and was almost 19 at stage 46. The ratio of all-trans 3-dehydroretinyl ester to retinyl ester, also, increased after stage 42 and reached 11 at stage 46. The mechanism of 11-cis formation during development is discussed in relation to retinoid conversions in the eyes.

Animals↗
PubMed1988

Anemia and anti-erythrocyte antibodies developed after repeated injections of sonicated preparations of Plasmodium berghei and Babesia rodhaini.

Anemia developed in mice after repeated injections of sonicated preparations of Plasmodium berghei and Babesia rodhaini. Anti-erythrocyte antibodies were detected in sera by an enzyme-linked immunosorbent assay and their levels rose as anemia developed. Administration of carbon particle suspension to block the mononuclear phagocyte system was effective to inhibit anemia induced by injections of sonicated parasite preparations. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analyses were carried out to examine autoantigens on the surface of the erythrocyte membrane reacting to anti-erythrocyte antibodies. The anti-erythrocyte antibodies from mice injected with the sonicated P. berghei preparations bound specifically to three components of the erythrocyte membrane. The anti-erythrocyte antibodies produced by the sonicated B. rodhaini preparations also reacted with four components, two of which corresponded to those reacting after the injection of the sonicated P. berghei preparations. These results suggest that both P. berghei and B. rodhaini organisms have some materials capable of inducing production of the anti-erythrocyte antibodies which mediate erythrophagocytosis by macrophages of the mononuclear phagocyte system during Plasmodium and Babesia infections.

Anemia↗
PubMed1988

Partial purification and properties of a plasma ouabain-like inhibitor of Na+, K+-ATPase in patients with essential hypertension.

Plasma levels of an ouabain-like inhibitor of Na+,K+-ATPase were higher in patients with essential hypertension compared with normal levels. The ouabain-like inhibitor was correlated significantly with blood pressure and was increased by a high-salt diet. The substance was partially purified by high performance liquid chromatography which revealed lipid-like properties, but the elution time was different from that of free unsaturated fatty acid on silica-gel high performance liquid chromatography. Its molecular weight was 600 or less, as estimated by high performance liquid chromatography with an HSG-15H column. The ouabain-like substance inhibited Na+, K+-ATPase in competition with KCl and showed positive ouabain-like immunoreactivity, whereas lysophosphatidylcholine was a non-competitive inhibitor. The ouabain-like substance was unstable at room temperature and decomposed to smaller molecular compounds which did not inhibit Na+, K+-ATPase. The inhibitory fraction gave a positive thiobarbituric acid reaction test. The mobility of the ouabain-like inhibitor on silica-gel thin-layer chromatography was different from that of prostaglandins and arachidonic acid. These results indicate that the plasma ouabain-like inhibitor of patients with essential hypertension is a lipid which is different from free fatty acid or lysophosphatidylcholine, and may be an unstable peroxide.

Cardenolides↗
PubMed1988

Effects of various nucleosides on antiviral activity and metabolism of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil against herpes simplex virus types 1 and 2.

Uptake of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU) into herpes simplex virus type 1 (HSV-1)- and 2 (HSV-2)-infected cells was elevated about 190 to 40 times, compared with that into mock-infected human embryo lung fibroblast cells. Uptake was not enhanced by infection with thymidine kinase-negative HSV-1 and HSV-2 mutants, however. In HSV-1-infected cells, 9.7% of BV-araU was phosphorylated to BV-araU triphosphate, but only 1.1% was phosphorylated in HSV-2-infected cells. The antiviral effect, uptake, and turnover of BV-araU were inhibited significantly by thymidine (dThd), moderately by deoxyuridine, and not at all by deoxycytidine. On the other hand, the antiviral activity of acyclovir (ACV) was inhibited only by dThd. The effect of BV-araU was influenced by dThd and dThd phosphates (mono-, di-, and triphosphates), and the effect of ACV was influenced only by dThd, which competitively inhibited the phosphorylation of ACV to ACV monophosphate. The combination of 5-fluorodeoxyuridine (FUdR)-BV-araU or FUdR-ACV had a synergistic effect on HSV-1 and HSV-2 replication. The effect of FUdR on the turnover of BV-araU in HSV-1- and HSV-2-infected cells was analyzed by high-performance liquid chromatography. In HSV-1-infected cells, 86% of the BV-araU was phosphorylated to BV-araU triphosphate, but no effect was observed in HSV-2-infected cells, in which 98% of the BV-araU remained as BV-araU monophosphate.

Antiviral Agents↗
PubMed1988

Portosystemic shunting in portal hypertension: evaluation with portal scintigraphy with transrectally administered I-123 IMP.

Portosystemic shunting was evaluated with rectal administration of iodine-123 iodoamphetamine (IMP) in seven patients without liver disease and 53 patients with liver cirrhosis. IMP (2-3 mCi [74-111 MBq]) was administered to the rectum through a catheter. Images of the chest and abdomen were obtained for up to 60 minutes with a scintillation camera interfaced with a computer. In all patients, images of the liver and/or lungs were observed within 5-10 minutes and became clear with time. In patients without liver disease, only liver images could be obtained, whereas the lung was visualized with or without the liver in all patients with liver cirrhosis. The portosystemic shunt index was calculated by dividing counts of lungs by counts of liver and lung. These values were significantly higher in liver cirrhosis, especially in the decompensated stage. Transrectal portal scintigraphy with IMP appears to be a useful method for noninvasive and quantitative evaluation of portosystemic shunting in portal hypertension.

Administration, Rectal↗
PubMed1988

Retinoid changes in the in vitro regeneration of frog visual pigments.

To investigate the regeneration of visual pigment, the changes in composition and quantity of retinoids were measured by high-performance liquid chromatography (HPLC). Eye cups or eye cup sections of dark-adapted frogs were exposed to light (greater than 500 nm) and incubated in the dark for several hours (pH 7.4, 27 +/- 1 degree C). Retinoids extracted by the oxime method before and after illumination were analysed by HPLC. In the dark, every eye cup or eye cup section contained 11-cis and all-trans isomers of retinyl palmitate (the proportion of 11-cis was nearly 40%). The amount of retinyl palmitate was 1-1.5 mol equiv of visual pigment. After 80% of the visual pigment had been bleached by illumination, eye cups or eye cup sections were incubated in the dark for 10 h. During the incubation, 70% of the bleached pigment was regenerated, and the proportion of 11-cis retinyl ester decreased from 40% to 13%. These results indicate that stored 11-cis retinyl ester is used for the regeneration. The regeneration rate of A2-pigment (half time = 75 min) was faster than that of A1-pigment (half time = 90 min), consistent with the result of Tsin & Flores' (1986) in vivo experiment with goldfish.

Animals↗