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Biomedical subjects

S Inoue

Publications and source records attributed to S Inoue.

At least 1,531 records · Page 85Linked to original sources
PubMed1981

Synthesis and antitumor activity of cysteinyl-3,4-dihydroxyphenylalanines and related compounds.

The natural catecholic amino acid 5-S-cysteinyl-3,4-dihydroxyphenylalanine (1) was selectively toxic to a variety of human tumor cell lines in culture and exhibited antitumor activity against L1210 leukemia and B-16 melanoma in mice at doses which were not toxic to the host. Structural analogues of 5-S-cysteinyl-3,4-dihydroxyphenylalanine including several new compounds, were synthesized and tested for growth inhibition of cultured cells of human neuroblastoma YT-nu and Chinese hamster fibroblasts Don-6. Some were also examined for antitumor activity against L1210 and B-16 in vivo. 4-S-Cysteinylcatechols and 2- and 4-S-cyteinylphenols, which cannot be prepared by conventional methods, were synthesized by the reaction of catechols and phenols with cystine and boiling aqueous HBr. 5-S-Cysteinyl- and 2-S-Cysteinyl-3,4-dihyroxyphenylalanine (1 and 2), L-3,4-dihydroxyphenylalanine (L-Dopa), and 2- and 4-S-cysteinylphenol (14 and 15) were toxic to the YT-nu cell line only, while 4-S-cysteinylcatechol (6), 3-S-cysteinyl-5-methylcatechol (8), 5-S-cysteaminyldopamine (9), and 4-methylcatechol were strongly toxic to both cell lines. Compound I (1000 mg/kg), 6 (500 mg/kg), and 8 (400 mg/kg) increased the life span of L1210-bearing mice by 50, 50, and 43%, respectively, and compounds 1 and 8 were marginally effective against B-16 melanoma as well. Compound 9 was too toxic to show any activity. There was a good correlation between the cytotoxicity and the in vivo activity.

Animals↗
PubMed1981

New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity.

In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of lambda phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were much higher than those for cell growth inhibition but similar to those for inhibition of lambda phage multiplication. Transduction analysis with lambda phages carrying the chromosomal fragment of the tnaA-gyrB region suggested that one of the mutations, nal-31, was located on the gyrB gene.

Bacteriophage lambda↗
PubMed1981

K+ selectivity and HCl secretion in Xenopus and their relation to cAMP and Ba2+.

Doses of 1, 5, and 10 mM adenosine 3',5'-cyclic monophosphate (cAMP) applied to previously resting Xenopus gastric mucosae initiated a dose-dependent acid secretory response. Increases in the K+ concentration of the submucosal solution. [K+sm], resulted in higher acid secretory rates and concomitant lower transmucosal resistances at the indicated cAMP concentration. The transmucosal potential difference, PD, had a liner slope against log [K+sm] over the range of 20-80 mM K+sm. Values of the slope (K+ selectivity, -PD/log[K+sm]) were less than 26 mV/log for resting mucosae, and in the range of 29-58 mV/log for both spontaneously secreting and cAMP-stimulated mucosae. These values were dose dependent on the cAmP concentration. In the presence of 10 mM Ba2+ together with cAMP, the K+ selectivity and the H+ secretory rate decreased compared with the case of cAMP only.

Animals↗
PubMed1981

Inhibition of bone marrow stem cell growth in vitro by methylmalonic acid: a mechanism for pancytopenia in a patient with methylmalonic acidemia.

A 7-week-old infant with methylmalonic acidemia had pancytopenia and hypoplastic bone marrow. The patient responded to large doses of vitamin B12 treatment, and within 3 wk, the blood counts and bone marrow cellularity returned to normal. To understand the mechanism of marrow depression in this infant, we examined the effect of the patient's plasma and methylmalonic acid itself on the in vitro growth of bone marrow-committed stem cells. The patient's plasma obtained before B12 treatment completely inhibited the marrow cell growth, whereas the posttreatment plasma showed no inhibition. Methylmalonic acid when added to the culture dishes in concentrations comparable to those reported in plasma of methylmalonic acidemia patients, inhibited growth of marrow stem cells in a concentration-dependent fashion. On the other hand, 16 to 18 hr incubation of cells in the same concentration of methylmalonic acid did not affect the recovery of viability of the cells. The observations suggest that methylmalonic acid is inhibitory to the proliferation of marrow stem cells. The mechanism of inhibition is yet to be elucidated.

Bone Marrow↗
PubMed1981

Time course of content of insulin, glucagon and pancreatic polypeptide in human pancreatic tissue obtained by surgery.

In order to know the degree of the destruction of peptide hormones in pancreatic tissue of autopsied material, the time courses of the degradation of pancreatic insulin, glucagon and hPP were studied using surgically operated pancreatic pieces kept at room or low temperature. Amounts of insulin, glucagon and hPP in pancreatic tissue were determined by radioimmunoassay. Insulin in the pancreas just after resection was 2.58 +/- 0.33 U/g (mean +/- SE). At 3 hrs it decreased to 66.4 +/- 3.8%, at 6 hrs, to 68.5 +/- 5.1% and at 12 hrs to 51.7 +/- 11.4% of the initial value in the tissues kept at room temperature (20-22 degrees C) When the tissues were kept at 4 degrees C, 90.7 +/- 3.9% of insulin at 3 hrs, 88.5 +/- 7.0% at 6 hrs, and 80.3 +/- 2.6% at 12 hrs were preserved. 81.3 +/- 13.9% of the initial hPP was present in the tissues after 6 hrs at room temperature, and it decreased to 20.7 +/- 5.7% after 12 hrs, whereas no significant decrease in hPP was found even after 12 hrs at low temperature. Glucagon content at starting point was 16.85 +/- 4.05 micrograms/g and at 3 hrs in the room temperature it fell to 7.46 +/- 3.53 micrograms/g (41.5 +/- 9.8%) and at 6 and 12 hrs only 14.4 +/- 4.1% and 5.8 +/- 4.2% were left, respectively. At low temperature, at 3 hrs 79.3 +/- 8.9%, at 6 hrs 62.2 +/- 14.7% and at 12 hrs 53.5 +/- 16.6% was preserved. These findings indicate that special consideration should be taken from the viewpoint of the destruction of hormones in pancreatic tissues obtained at autopsy.

Glucagon↗
PubMed1981

[Study on the metabolism of prostaglandin F2 alpha in human placenta (author's transl)].

The activity of 15-hydroxy prostaglandin dehydrogenase (15 OH-PGDH) was studied in the human placenta by the biochemical determination and enzyme histochemical technique. The placentae of 6-40 weeks of gestation were obtained from artificial abortion, spontaneous abortion and normal delivery. 1) The capability of prostaglandin metabolism in the placenta increased according to gestational age. 2) The relative potency of 15 OH-PGDH activity among different tissues was placenta villi greater than chorion greater than decidua greater than amnion. The enzyme histochemical technique has disclosed the same results. 3) The conversion rate of PGF2 alpha to 15-keto PGF 2 alpha was dominant in the maternal side rather than fetal blood vessel system in the perfusion experiment of placenta. 4) The strong activity of 15 OH-PGDH was mainly localized in the syncytiotrophoblasts of placenta villi. 5) The activity of 15 OH-PGDH decreased in the placenta of abortion. The decrease of this enzyme activity was not detected in the toxemia of pregnancy. It has been postulated that endogenous and exogenous prostaglandin, which possesses strong and multiple biological activity, increases in the pregnancy. The present results suggest that the prostaglandin metabolic system in the placenta has the important role in the continuity of pregnancy.

Chorionic Villi↗