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Biomedical subjects

K Takagi

Publications and source records attributed to K Takagi.

At least 667 records · Page 37Linked to original sources
PubMed1986

Determination of serum delta 5-3 beta-hydroxysteroid sulphates by combined high-performance liquid chromatography and immobilized 3 beta,17 beta-hydroxysteroid dehydrogenase in column form.

We studied the use of an immobilized enzyme, covalently bound to aminopropyl-CPG, in the analysis of individual delta 5-3 beta-hydroxysteroid sulphates. A microcolumn with immobilized 3 beta,17 beta-hydroxysteroid dehydrogenase was prepared and used together with high-performance liquid chromatography (HPLC). The reduced nicotinamide-adenine dinucleotide produced from delta 5-3 beta-hydroxysteroids by this enzyme was fluorimetrically determined. The immobilized enzyme was sufficiently stable for at least one month or for 180 tests when used repeatedly. A clinical trial demonstrated that this HPLC-immobilized enzyme method is superior to the soluble enzyme method, giving reliable and reproducible results at a low cost.

Adult↗
PubMed1986

A new, modified operation for funnel chest using the Zimmer osteosynthetic plate.

A corrective operation for funnel chest using a Zimmer osteosynthetic plate, which can be bent to any configuration desired, is described. This operative method can be employed for any type of chest deformity in adults and adolescents. A physiologically normal and perfectly stabilized anterior chest wall is obtained with this plate system, and no relapse occurs even after removal of the plate.

Adolescent↗
PubMed1986

Clinical evaluation of serum 3 beta-hydroxy-5-cholenoic acid in hepatobiliary diseases.

Serum 3 beta-hydroxy-5-cholenoic acid (3 beta-OH-delta 5) was analyzed in 100 cases (90 patients with hepatobiliary diseases, 10 normal subjects) and its clinical significance investigated. The measurement of 3 beta-OH-delta 5 was performed by high performance liquid chromatography (HPLC) with immobilized 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) as the enzyme column. Esterified 3 beta-OH-delta 5 was measured after enzymatic hydrolysis with sulfatase and beta-glucuronidase. 3 beta-OH-delta 5 was hardly detected in normal cases. On the other hand, serum 3 beta-OH-delta 5 levels were remarkably high in cholestatic cases and also high in other cases with high bilirubin levels. The ratio of glycine- to taurine-conjugates (G/T ratio) was effective in discriminating cholestasis from hepatocellular damage such as in cases of acute hepatitis or fulminant hepatitis. More than 90% of the 3 beta-OH-delta 5, which is toxic, was sulfated or glucuronidated, suggesting detoxification by esterified bile acids. Significant increases of taurine-conjugated 3 beta-OH-delta 5 were observed in cases with pruritus, and a relationship between taurine-conjugated and pruritus was presumed. Therefore, analysis of 3 beta-OH-delta 5 is considered to be effective in clarifying the pathogenesis of hepatobiliary diseases.

3-Hydroxysteroid Dehydrogenases↗
PubMed1986

Clinical application of the perineal scan: prepartum screening for cord presentation.

Real-time linear-array ultrasonographic scanning was performed from the perineum on 12 primiparous term women with the fetus in breech or foot presentation. Scanning was done with the patient initially in lithotomy position and then in semi-Trendelenburg position if a better view was required. The technique appears to be excellent for visualization of the forelaying umbilical cord even when the cervix is closed and is not affected by the acoustic shadow of the public arch. The information obtained by the scanning may be of value in avoiding or improving perinatal mobility of breech/footling fetuses and in providing better perinatal management.

Breech Presentation↗
PubMed1986

Transfer function of right- and leftward eye movements in patients with unilateral labyrinth.

In patients with loss of unilateral labyrinthine function, the dynamic characteristics of rightward eye movement and leftward eye movement induced by the healthy labyrinth were displayed respectively. In patients who were examined within a few months after loss of unilateral labyrinthine function, the gain of eye movement toward the healthy labyrinth was low compared with that of eye movement toward the opposite direction. These differences in the gain were remarkable in the frequency range from 0.01 to 0.1 Hz. But those differences in the gain were not detected in patients who were examined more than 3 months after loss of unilateral labyrinthine function.

Adult↗
PubMed1986

The relationship between tissue levels of cyclic GMP and tracheal smooth muscle relaxation in the guinea-pig.

The effect of cyclic GMP was investigated using guinea-pig tracheal smooth muscle. 8-Bromo-cyclic GMP showed a dose-dependent relaxation of spontaneous tension of tracheal smooth muscle. Administration of sodium nitroprusside induced dose-dependent relaxation of tracheal smooth muscle as well as an increase in tissue levels of cyclic GMP. Nicorandil, N-(2-hydroxyethyl) nicotinamide nitrate showed dose-dependent relaxation of tracheal smooth muscle and an increase in cyclic GMP levels in the tissue. N-(2-aminoethyl) nicotinamide dihydrochloride, which is a nicorandil derivative and differs minimally in its molecular structure (-NH2 vs -NO2), had neither a relaxant effect on tracheal smooth muscle nor did it increase the level of cyclic GMP in the tissue. The rise cyclic GMP levels preceded the relaxation of tracheal smooth muscle induced by sodium nitroprusside. These results suggest that cyclic GMP is one of the relaxant factors and that nitro-derivatives exhibit their relaxant effect on the smooth muscle mediated by an increase in cyclic GMP level.

Animals↗
PubMed1986

Effects of verapamil on the response of the guinea-pig tracheal muscle to carbachol.

The effects of verapamil on the contraction of the guinea-pig tracheal smooth muscle induced by calcium (Ca2+) or barium (Ba2+) were investigated in three different conditions: (a) in excess K solution, (b) in the presence of carbachol, and (c) in excess K solution containing carbachol. In order to clarify the contractions, the effects of removal and readdition of the divalent cations were also investigated. In Ca2+-loaded tissues, application of carbachol in Ca-free medium produced a transient contraction, the magnitude of which decreased the longer the duration of exposure to Ca2+-free solution. In Ca2+-depleted, Ba2+-loaded tissues, application of carbachol in a Ba2+- and Ca2+-free medium produced a transient contraction the magnitude of which decreased the longer the duration of exposure to the Ba2+- and Ca2+-free solution. After exposure to Ca2+-free solution for 40 min, the sensitivity of the tissue to Ca2+ was greater in the presence of 30 microM carbachol (ED50 = 0.06 mM) than in the presence of 40 mM K+ (ED50 = 0.3 mM). The Ca2+-sensitivity in the presence of 30 microM carbachol plus K+ (40 mM) was not different from that in the presence of 30 microM carbachol alone. In Ca2+-free solution, the sensitivity of the tissue to Ba2+ in the presence of 40 mM K+ (ED50 = 1.4 mM) was not different from that observed in the presence of 30 microM carbachol (ED50 = 1.3 mM). 6 After exposure to Ca2+-free solution, verapamil produced a parallel rightward shift in the concentration-response curves to added Ca2+ and Ba2+ in the presence of either 40 mM K+, 30 microM carbachol or 40mM K+ plus 30 microM carbachol. 7 The pA2 values of verapamil against Ca2+ responses in the presence of 40 mM K+, 30 microM carbachol and 40 mM K+ plus 30 microM carbachol were 7.0, 6.5 and 6.5, respectively. The pA2 values of verapamil against Ba2+ responses under these conditions were 7.1, 7.0 and 7.1, respectively. 8 It is concluded that the sustained contraction produced by carbachol requires the influx of Ca2+ and that Ba2+ can substitute for Ca2+ in this process. Furthermore, the ionic channels which admit Ca2+ may be modified by carbachol to different degrees depending on the presence of Ca2+ or Ba2+. Such changes alter the affinity of the channel to verapamil.

Animals↗
PubMed1986

Effects of relaxants on electrical and mechanical activities in the guinea-pig tracheal muscle.

In isolated tracheal muscles of the guinea-pig, effects of several relaxants were studied by simultaneously recording the membrane potential and mechanical response. Intracellular recordings showed regular slow waves in most preparations. There was a close correlation between membrane potential and slow wave amplitude. The linear regression line of the slow wave amplitude (Y mV) on the membrane potential (X mV) could be expressed by Y = -0.35X-5.9. The mean values of resting potential and slow wave amplitude were -50.6 +/- 0.6 mV and 11.9 +/- 0.5 mV, respectively. Relaxant drugs used (isoprenaline, terbutaline, adrenaline, noradrenaline, theophylline, forskolin and dibutyryl cyclic AMP) all produced hyperpolarization of the membrane and abolished the slow wave. The degree of relaxation was closely related to these electrical responses, although the recovery of electrical responses was faster than the mechanical response. It was concluded that the relaxation caused by the agents, which are known to increase the intracellular cyclic AMP level, was accompanied by a clear hyperpolarization and suppression of slow waves.

Animals↗
PubMed1986

The role of phospholipase in reduced beta-adrenergic responsiveness in experimental asthma.

This investigation was designed to elucidate the role of phospholipase (PLase) in relation to reduced beta-adrenergic responsiveness in guinea pigs subjected to experimental asthma. In the in vivo experiment, guinea pigs that had developed asthma-like symptoms after exposure to an aerosol of 2% ovalbumin for 7 to 8 min for 10 successive days were used as the experimental asthma group. The control group was exposed to saline. The endogenous PLase activity was determined by high performance liquid chromatography using ditridecanoyl phosphatidylcholine as a substrate. PLase activity of lung membranes in the experimental asthma group was significantly elevated by 50% compared with that in the control group. Phospholipid content of lung membranes in the experimental asthma group was decreased by 11% compared with that in the control group. The experimental asthma group showed a 37% decrease in the number of beta-adrenoceptors in lung membranes and a 54% decrease in isoproterenol-stimulated adenylate cyclase activity in lung membranes compared with the control group. Although forskolin-stimulated adenylate cyclase activity was also reduced by 24%, decreases in forskolin-stimulated activity were less than decreases in isoproterenol-stimulated activity. In the in vitro experiment phospholipids in lung membranes were degraded by pretreatment with 0.1 U of PLase A2. After pretreatment of lung membranes with PLase A2, the number of beta-adrenoceptors was reduced by 25% compared with that in the control group, and adenylate cyclase activity stimulated by isoproterenol and forskolin were also reduced by 67 and 28%, respectively. PLase A2 had a minor effect on forskolin-stimulated activity as compared with isoproterenol-stimulated activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1986

Changes in intracellular K+ and Na+ ion concentrations during cell growth and differentiation.

We compared intracellular K+ and Na+ ion concentrations during cell growth and differentiation of a mouse myeloid leukemia M1 cell line. Cells undergoing mitosis had higher K+ concentrations than quiescent cells. Treatment with a K+ channel blocker and furosemide enhanced cell growth and produced a slight increase in the intracellular K+ concentration. Treatment with reagents that reduced the intracellular K+ concentration stopped cell growth. Induction of differentiation in this cell line produced a decrease in the K+ concentration, which always was accompanied by an increase in the Na+ concentration. Treatment with ouabain, which decreased the intracellular K+ concentration, did not, however, induce differentiation in the M1 cell line. The data suggest that cell growth and differentiation in the M1 cells are accompanied by changes in the intracellular K+ and Na+ concentrations but that the changes in the contents of these monovalent cations do not necessarily induce differentiation in this cell line.

Animals↗
PubMed1986

The role of leukotriene B4 in the genesis of oxygen toxicity in the lung.

Leukotriene B4 (LTB4) is a metabolite of arachidonic acid that has potent chemotactic activity for polymorphonuclear leukocytes (PMN). Pulmonary oxygen toxicity is considered to be a good model of an acute inflammatory lung injury, and an increase in the number of PMN is found in the lungs acutely injured by hyperoxia. In order to estimate the role of LTB4 responsible for this influx of PMN, we measured the LTB4 by radioimmunoassay in lung lavages of rats exposed to hyperoxia for 60 h. We found that the level of LTB4 in lung lavages in rats exposed to hyperoxia for 60 h increased significantly compared with that in normoxic control rats. At the same time, the marked increase in the number of PMN in lung lavages and the decrease in the activity of NADPH-cytochrome c reductase in lung microsomes were also observed. The administration of AA861, a 5-lipoxygenase inhibitor, reduced not only the increase in LTB4 but also the increase in the number of PMN in lung lavages of rats exposed to hyperoxia for 60 h. Furthermore, treatment with AA861 also protected the decrease in the activity of NADPH-cytochrome c reductase. The effects of AA861 on these parameters were observed in a dose-dependent fashion. In addition, there is a good correlation between the level of LTB4 and the number of PMN in the lavage of rats exposed to hyperoxia for 60 h with or without AA861 administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Mechanism of rat lung microsomal dysfunction induced by oxygen breathing in relation to the effect of alpha-tocopherol.

The toxic effect of high oxygen concentrations on the lung was investigated together with the effect of alpha-tocopherol (Juvela). Rats were exposed to 80, 60 or 40% oxygen for 2, 4 or 8 days with or without alpha-tocopherol treatment. The composition of fatty acids in microsomal phospholipids was determined by high-performance liquid chromatography. Microsomal electron transport activity and the levels of lipoperoxides in lung microsomes were determined by measuring the specific activity of NADPH (reduced nicotinamide adenine dinucleotide phosphate)-cytochrome c reductase and by spectrophotometry, respectively. Exposure to 80 or 60% oxygen induced significant decreases in the contents of arachidonic and docosahexaenoic acids, and also reduced microsomal electron transport activity. The level of lipoperoxides was elevated on the 2nd day of exposure to 80 or 60% oxygen, however, it returned to normal thereafter. On the other hand, exposure to 40% oxygen affected none of these parameters. Treatment with alpha-tocopherol prevented the changes in those fatty acids and microsomal function up to 2 days with exposure to 80% oxygen and up to 4 days with exposure to 60% oxygen. However, microsomal dysfunction and reductions of arachidonic and docosahexaenoic acids contents were observed after the 4th day of exposure to 80% oxygen or the 8th day of exposure to 60% oxygen irrespective of alpha-tocopherol administration. On the contrary, alpha-tocopherol administration prevented an elevation of the level of lipoperoxides. These results suggest that lung microsomal dysfunction induced by over 60% oxygen breathing is ascribed to the alteration of fatty acids composition in microsomal phospholipids and that alpha-tocopherol has a protective effect in the early phase.

Animals↗
PubMed1986

[Combination chemotherapy with vincristin, actinomycin D, cyclophosphamide and adriamycin in soft-part sarcoma].

Fifteen patients with soft-part sarcoma were treated with combination chemotherapy consisting of vincristin, actinomycin D, cyclophosphamide and adriamycin (VACA therapy). The cumulative five-year survival rate by the Kaplan-Meier method was about 73%. This VACA therapy was effective for malignant fibrous histiocytoma and synovial sarcoma as well as rhabdomyosarcoma. Side effects such as anemia, leucocytopenia, nausea and alopecia were observed, but could be managed. VACA therapy is considered to be useful as a combination chemotherapy for patients with soft-part sarcoma.

Adolescent↗