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Biomedical subjects

H Noguchi

Publications and source records attributed to H Noguchi.

At least 343 records · Page 19Linked to original sources
PubMed1986

Combined capillary column gas chromatography/electron capture negative ion chemical ionization mass spectrometry of dihydropyridine calcium antagonists.

Several dihydropyridine calcium antagonists showed intense [M]-. ion peaks as the base peaks and a few fragment peaks in the electron capture negative ion chemical ionization mass spectra. The peak intensities of the [M]-. ion of these antagonists were about 100 times as high as those of the most abundant positive ion. The use of a capillary column connected directly to the ion source prevents the oxidation of these agents in the column and the transfer line. Furthermore, the presence of plasma extract decreases the oxidation of these agents in the injection port. The limits of sensitivity with this technique are 500 fg-5 pg on the column. Combined capillary column gas chromatography/electron capture negative ion chemical ionization mass spectrometry should be suitable for sensitive and specific assays of dihydropyridine calcium antagonists in biological fluids.

Body Fluids↗
PubMed1986

Phototropism in Hypocotyls of Radish : I. Isolation and Identification of Growth Inhibitors, cis- and trans-Raphanusanins and Raphanusamide, Involved in Phototropism of Radish Hypocotyls.

Three growth inhibitors which might be involved in phototropism of Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls, were isolated as crystalline forms from light-exposed radish seedlings and identified as cis- and trans-raphanusanins and 6-methoxy-2,3,4,5-tetrahydro-1,3-oxazepin-2-one (designated raphanusamide). The cis- and trans-raphanusanins inhibited growth of etiolated radish hypocotyls at concentrations higher than 1.5 micromolar, raphanusamide at concentrations higher than 20 micromolar.

Journal Article↗
PubMed1986

Phototropism in Hypocotyls of Radish : II. Role of cis- and trans-Raphanusanins, and Raphanusamide in Phototropism of Radish Hypocotyls.

When etiolated radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls were subjected to a continuous unilateral illumination with white fluorescent light (0.1 watt per square meter), the growth rate at the lighted side was strongly inhibited for the first 2 hours, while that at the shaded side showed no change. After 2.5 hours growth on the lighted side recovered gradually, while that on the shaded side was slightly inhibited. The neutral growth inhibitors, cis- and trans-raphanusanins and raphanusamide, were determined in the lighted and shaded sides from 1 hour before until 2 hours after the start of unilateral illumination. In the lighted side, cis- and trans-raphanusanins increased by 0.5 hour after the start of illumination, reached 3 to 3.5-fold greater concentrations than in the shaded side after 1 hour, and then decreased gradually. Raphanusamide increased in the lighted side to a 3-fold greater concentration than that in the shaded one 2 hours after the start of the illumination. Unilateral applications of cis- and trans-raphanusanins and raphanusamide suppressed the growth of the hypocotyl on the applied side more than that on the opposite one, causing the hypocotyls to bend towards the site of application. The data suggest that phototropic curvature in radish is caused by the light-induced synthesis of growth-inhibiting cis- and trans-raphanusanins, and raphanusamide at the site of illumination.

Journal Article↗
PubMed1986

N-sulphoconjugation of alicyclic, alkyl- and aryl-amines in vivo and in vitro.

Radioactive 35S in 3'-phosphoadenosine 5'-phosphosulphate was incorporated into alicyclic, alkyl- and aryl- amines in the presence of hepatic 105 000 g supernatants of female rats. 4-Phenylpiperazine, 4-phenyl-1,2,3,6-tetrahydropyridine (PTHP), 1,2,3,4-tetrahydroisoquinoline, N-methylbenzylamine, desmethylzotepine and desmethylzimeldine showed the highest conjugation with 35SO3 among the amines tested. Incorporation of 35SO3 into alicyclic and alkyl-amines was higher at pH 10.0 than at pH 7.4 but the incorporation into arylamines was the opposite. A greater amount of 35SO3 was incorporated into the secondary alkylamines than the corresponding primary amines. Radioactive reaction products were identified as N-sulphoconjugates of amines by comparison on t.l.c. with synthetic authentic compounds. Reaction products of desmethylimipramine (DMI) and PTHP in vitro were isolated as their sulphoconjugates, identified by comparison of field desorption mass spectra, u.v. spectra, retention time on h.p.l.c. and RF values on t.l.c. with synthetic standards. DMI N-sulphonate and PTHP N-sulphonate were detected in the body of female rats treated orally with DMI and PTHP, respectively. These results indicate that N-sulphoconjugation is a common metabolic pathway of alicyclic, alkyl- and aryl-amines in vivo and in vitro.

Adenine Nucleotides↗
PubMed1986

Age- and sex-related changes in amine sulphoconjugations in Sprague-Dawley strain rats. Comparison with phenol and alcohol sulphoconjugations.

Age- and sex-related changes in sulphoconjugation were investigated in hepatic 105 000 g supernatants of three-week-old (young), seven-week-old (young adult), one-year-old (middle-aged) and two-year-old (old) Sprague-Dawley rats in the presence of biologically active sulphate. The supernatants of seven-week-old, one-year-old and two-year-old female rats catalysed the sulphoconjugations of alcohol (tiaramide as substrate), and alicyclic amine, alkylamine and arylamine more rapidly than those of the respective males, but the supernatants of three-week-old rats did not exhibit significant sex-related differences. The sulphoconjugations by the supernatants of female rats were substantially constant during ageing. On the other hand, the supernatants of seven-week-old male rats catalysed phenol (beta-naphthol as substrate) sulphoconjugation more rapidly than those of seven-week-old females, but the supernatants of two-year-old rats did not exhibit this sex-related difference. These results indicate that the substrates for sulphoconjugation could be divided into at least two groups: an alcohol and amine type, and a phenol type.

Age Factors↗
PubMed1986

[Radiation-induced secondary cancer in patients with uterine carcinoma].

PURPOSE: Radiation-induced cancer has been epidemiologically investigated in occupational or atomic radiation exposure cases. These is also a need to clarify the risk in the case of radiotherapeutical exposure. In this study, therefore, cases of post-irradiated uterine carcinoma which was well cured and followed up over a long term were selected for statistical analysis of radiation-induced cancer in the medical division. MATERIALS AND METHODS: A total of 19,384 patients with uterine carcinoma at seven institutions in Japan were registered on a computer system at the NIRS and were statistically analyzed. Of these, 6,655 patients were treated by surgical procedure alone, 4,310 were given a combined treatment modality of radiation and surgery, 8,419 were treated by radiation alone between 1960 and 1978. Radiation-induced cancer was defined according to the following categories: Secondary cancer was developed within the irradiated field. Time interval was over 5 years after the initial irradiation (leukemia was over 2 years). The cancer had a different histological type to the original one. A total of 43 patients with induced cancer were observed, namely: 14 with rectal cancer, 8 with leukemia, 6 with uterine corpus cancer, 4 with urinary bladder cancer, 3 with osteosarcoma or uterine sarcoma, 2 with sigmoid colon cancer or malignant fibrous histiocytoma, and 1 with ovarian cancer, respectively. RESULTS: Rectal cancer, leukemia and urinary bladder cancer were initially analyzed, because their expected values were easily estimated from the basic data. A total of 8,333 patients (43,418 person-years) from 7 institutions were considered. Their average follow-up period was 10.2 years after treatment. 1) Rectal cancer: Observed value (O) = 14, expected value (E) = 7.83, O/E = 1.79, 95% confidence interval of O/E ratio (CI) = 0.98-2.99, there was no significant difference. 2) Leukemia: O = 8, E = 3.78, O/E = 2.12, CI = 0.91-4.18, no significant difference. 3) Urinary bladder cancer: O = 4, E = 2.23, O/E = 1.79, CI = 0.49-4.55, no significant difference. In other words, no significant difference was observed in the risk of occurrence of secondary cancer among the total number of irradiated patients from the 7 institutions. Since these results, however, were influenced by the accuracy of patient follow-up, the O/E ratio of double cancer in each institution was observed to check the accuracy of the follow-up and 3 institutions were selected for further analysis comprising 2,686 patients (13,588 person-years) in all. Their average follow-up period was 10.1 years.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1986

[Effect of serotonin on uteroplacentofetal circulatory system in pregnant rabbit].

The effects of serotonin (5-hydroxytryptamine) on the uteroplacentofetal circulatory system were studied in pregnant rabbits. Serotonin infusion (50 micrograms/kg) induced transient, but significant fetal bradycardia (deceleration), without any significant changes in maternal blood pressure, heart rates, pO2, pCO2 and uterine activities. Pretreatment with methysergide, a serotonin antagonist, with a dose of 2.5 mg/kg blocked the inhibitory effect of serotonin on fetal heart rate. However, methysergide itself produced the uterine contraction associated with mild fetal bradycardia. Direct injection of serotonin (1,000 micrograms/kg) into fetuses did not produce any changes in fetal heart rates. These data indicated that serotonin would influence the uteroplacental vasculature, which in turn induced fetal bradycardia.

Animals↗
PubMed1985

Determination of nilvadipine in human plasma by capillary column gas chromatography-negative-ion chemical-ionization mass spectrometry.

A highly sensitive and specific method for the determination of nilvadipine, a new dihydropyridine calcium antagonist, in human plasma is described. A deuterated analogue of nilvadipine is added to the plasma as an internal standard. The agent and its internal standard are extracted at pH 9 from the plasma into a benzene--n-hexane (1:1) mixture. The extract is analysed by fused-silica capillary column gas chromatography--negative-ion chemical-ionization mass spectrometry with methane as the reagent gas. The mass spectrometer is set to monitor the negative molecular ions of the agent and internal standard. Quantitation is possible down to 0.01 ng/ml using 1 ml of plasma. The coefficients of variation of the method are 6.4 and 2.1% at the 0.01 and 0.1 ng/ml levels, respectively. Plasma levels obtained with this method are given for four healthy volunteers who had received a 6-mg oral dose of nilvadipine.

Calcium Channel Blockers↗
PubMed1985

Microwave tissue coagulation applied clinically in endoscopic surgery.

On the basis of the ample basic knowledge acquired by repeated experiments, we applied our microwave tissue coagulator in endoscopic surgery, in a total of 59 patients with benign and malignant lesions encountered during a period of two years beginning in July, 1981. Hemostasis was achieved in 96.5% of all the cases with bleeding lesions in the digestive tract. Stenosis was alleviated in 86% of the cases with esophageal or rectal stenosis. Furthermore, the technique was successfully used for hemostasis and tumor reduction in inoperable early cancer cases. Our device is unique in that the electrode is thrust into tissue, which assures us of a satisfactory result. In this point, it must be clearly distinguished from an electrocoagulator or a laser coagulator, which is associated with a risk of injuring intact tissue. The range of coagulation is adjustable by changing the length of the monopolar antenna and electric output, and by employing a coaxial cable of appropriate thickness. In conclusion, our microwave tissue coagulator can be used easily and safely in clinical endoscopic surgery.

Adult↗
PubMed1985

Purification and some properties of chalcone synthase from a carrot suspension culture induced for anthocyanin synthesis and preparation of its specific antiserum.

Chalcone synthase was purified to homogeneity by polyacrylamide gel electrophoresis from cell suspension cultures of carrot in which anthocyanin synthesis was induced by transferring the cells from a medium containing 2,4-dichlorophenoxy-acetic acid (2,4-D) to one lacking it. A molecular weight of 80,000-85,000 for the enzyme was determined by gel filtration and disc-gel polyacrylamide electrophoresis, and one of about 40,600 for the subunit by SDS slab-gel electrophoresis. The primary reaction product was chalcone and the pH optimum of the reaction was 8.0. The Km values for 4-coumaroyl-CoA and malonyl-CoA were 5.7 microM and 18 microM, respectively. These properties of carrot chalcone synthase were discussed in comparison to those of that from cell cultures of parsley reported previously. Antiserum against chalcone synthase from carrot was obtained from mice bred under specific pathogen free conditions. Crossreactivity was examined by Western-blotting, and the high specificity of the antiserum against chalcone synthase was demonstrated.

Acyltransferases↗