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Biomedical subjects

I Inoue

Publications and source records attributed to I Inoue.

At least 253 records · Page 14Linked to original sources
PubMed1980

Synthesis and antitumor activity of cytosine and adenine nucleosides of unsaturated 5-(aminoacyl)aminopentofuranoses.

Direct synthesis of the 1- and 9-(5-azido-2,3,5-trideoxy-beta-D-glycero-pent-2-enofuranosyl) derivatives (3a and 3b) of cytosine and adenine, respectively, has been accomplished via treatment of the corresponding 2',3'-unsaturated nucleosides (1a and 1b) with triphenylphosphine and carbon tetrabromide in the presence of lithium azide. Members of a new type of (aminoacyl)amino nucleoside, the 1- and 9-[5-(aminoacyl)amino-2,3,5-trideoxy-beta-D-glycero-pent-2-enofuranosyl] derivatives of cytosine and adenine, respectively, have been obtained by condensation of the corresponding, unsaturated amino nucleosides with the active esters of several amino acid derivatives, followed by deprotection. These nucleosides were examined for in vivo antitumor activity against leukemia L-1210 and Sarcoma 180 (solid tumor) in mice; none of them exhibited antitumor activity against L-1210 in mice, but compounds 1a, 3a, and 1-[2,3,5-trideoxy-5-(L-methionyl)amino-beta-D-glycero-pent-2-enofuranosyl]cytosine exhibited weak activity against Sarcoma 180 (solid tumor).

Adenine↗
PubMed1980

Separation of the action potential into a Na-channel spike and a K-channel spike by tetrodotoxin and by tetraethylammonium ion in squid giant axons internally perfused with dilute Na-salt solutions.

Squid giant axons internally perfused with a 30 mM NaF solution and bathed in a 100 mM CaCl2 solution, which are known to produce long lasting action potentials in response to pulses of outward current, were investigated. The effects of tetrodotoxin (TTX) and of tetraethylammonium ion (TEA+) on such action potentials were studied. The results are summarized as follows: (a) An addition of 1--3 microM TTX to the external solution altered but did not block the action potentials; it increased the height of the action potential by approximately 15 mV, and it decreased the membrane conductance as the peak of excitation by about two-thirds. (b) Voltage-clamp experiments performed with both NaCl and TTX in the external CaCl2 solution revealed that the TTX-insensitive action potential does not involve a rise in gNa, whereas the experiments performed without TTX showed that the action potential is accompanied by a large rise in gNa. (c) Internally applied TEA+ was shown to selectively block the TTX-insensitive action potential, but it did not block the other component of the action potential, which is accompanied by a rise in gNa, and which is selectively suppressed by TTX. (d) The addition of a small amount of KCl to the external CaCl2 solution containing TTX greatly increased both the maximum peak inward current under voltage clamp and the maximum slope conductance. Furthermore, it was shown that K+ applied on both sides of the axon plays a dominant role in producing the membrane potential in the active state in the presence of TTX, even though a large amount of Ca2+ is presented in the bathing medium. These observations have led me to conclude that the sodium channel is responsible for the production of the TTX-sensitive component of the action potential under the ionic conditions of these experiments, and the potassium channel for the TTX-insensitive component of the action potential.

Animals↗
PubMed1979

Studies on biologically active halogenated compounds. 1. Synthesis and central nervous system depressant activity of 2-(fluoromethyl)-3-aryl-4(3H)-quinazolinone derivatives.

Some 2-(fluoromethyl) analogues of 2-methyl-3-aryl-4-(3H)-quinazolinones have been synthesized and screened for CNS activities. It was shown that the 2-(fluoromethyl) analogues possess in general more potent CNS depressant activities and less toxicities than their parent compounds. Of particular interest were the 2-(fluoromethyl) analogues (22, 24, and 31) of methaqualone and 6-aminomethaqualone. Compound 24 was more potent in CNS depressant activity and less toxic than methaqualone. Compound 31 exhbited potent central muscle relaxing activity and markedly reduced toxicity as compared with 6-aminomethaqualone.

Animals↗
PubMed1979

Studies on biologically active nucleosides and nucleotides. 5. Synthesis and antitumor activity of some 2,2'-anhydro-1-(3',5'-di-O-acyl-beta-D-arabinofuranosyl)cytosine salts and 2,2'-anhydro-1-(3'-O-acyl-beta-D-arabinofuranoxyl)cytosine 5'-phosphates.

A series of 3',5'-diesters of a 2,2'-anhydro-1-(beta-D-arabinofuranosyl)cytosine salt bearing functional substituents on the ester side chains (4--16) have been synthesized. The synthesis of these diesters involved the reaction between cytidine and the corresponding acid anhydride or acid chloride in the presence of boron trifluoride etherate. Similar reaction of bis(cytidine 5'-)suberate (21) with pivaloyl chloride gave bis[2,2'-anhydro-1-(3'-O-pivaloyl-beta-D-arabinofuranosyl)cytosine 5'-]suberate dihydrochloride (22). The reaction could also be extended to a one-step synthesis of 3'-esters of 2,2'-anhydro-1-(beta-D-arabinofuranosyl)cytosine 5'-phosphate (24) from 5'-cytidylic acid. These compounds have been examined for antitumor activity against L1210 leukemia in BDF1 mice. The diesters with a long-chain carboxylic acid (4c, 7c, 12, and 24d) showed high activity when administered intraperitoneally. The compound 24d exhibited moderate activity when administered orally.

Animals↗
PubMed1979

On the nature of the activating enzyme of the inactive form of delta-aminolevulinate synthetase in Rhodopseudomonas spheroides.

The activating enzyme of the inactive form of Fraction I of delta-aminolevulinate (ALA) synthetase [EC 2.3.1.37] in Rhodopseudomonas (R.) spheroides was purified about 1,000-fold from an extract of R. spheroides cells grown anaerobically in the light. The purification of the activating enzyme was achieved by fractionating the 100,000 X g supernatant fraction of the crude extract with ammonium sulfate and acetone, followed by Sephadex G-200 chromatography, pyridoxamine phosphate-Sepharose 4B chromatography, and preparative gel electrophoresis. The final preparation of the activating enzyme still contained a minor contaminant (less than 20%) as judged by disc gel electrophoresis. The activating enzyme exhibited cystathionase [EC 4.4.1.1] activity throughout the purification. These two enzyme activities were not separated at all during any step of the purification. An apparently homogeneous preparation of cystathionase [EC 4.4.1.8] purified from rat liver also exhibited activating activity in the presence of L-cystine. It was concluded that the activating enzyme is a cystathionase.

5-Aminolevulinate Synthetase↗
PubMed1977

Malignant fibrous mesothelioma of the tunica vaginalis: a histologic and ultrastructural study.

An unusual malignant fibrous tumor of the testicular tunic in a 35-year-old Japanese man is presented. It apparently arose from the visceral layer of the tunica vaginalis where focal mesothelial hyperplasia was seen. Microscopically the tumor consisted of interlacing bundles of spindle cells and numerous polygonal cells with variable amounts of collagen fibers. The electron microscopic study demonstrated the former cell type closely resembling the fibroblast and the latter to be more epithelial having very plump cytoplasm with fairly well developed desmosomes. The tumor was diagnosed as malignant fibrous mesothelioma upon histopathologic and ultrastructural comparison with the similar tumors in the pleura and peritoneum. Because of the scarcity of the diagnosis in the region it is suggested that fibrous paratesticular tumors are critically reviewed.

Adult↗
PubMed1977

Effect of somatostatin on neurotensin-induced glucagon release and hyperglycemia.

Administration of neurotensin to dogs resulted in rises in circulating blood glucose, glucagon and insulin levels, the rise in glucagon being more pronounced than that in insulin. Infusion of somatostatin along with neurotensin suppressed glucagon and insulin responses to neurotensin and prevented the rise in blood glucose levels. These results suggest that the hyperglycemia seen after neurotensin is due to neurotensin stimulation of glucagon release over insulin release.

Animals↗