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Biomedical subjects

A Inoue

Publications and source records attributed to A Inoue.

At least 559 records · Page 31Linked to original sources
PubMed1982

[Concentrations of cefmenoxime and cefotiam in the human bone marrow blood (author's transl)].

In order to examine the venous blood and bone marrow blood concentrations of cefmenoxime (CMX) and cefotiam (CTM) in man, 1 g of CMX or CTM was administered by one shot intravenous injection prior to surgery of the hip joint. At 30, 60, 120 and 180 minutes after the administration, venous blood and bone marrow blood were collected from each of 3 patients and the concentration assayed by the agar well method. Both CMX and CTM showed excellent distribution to bone marrow blood with peak levels of 50.1 micrograms/ml and 50.9 micrograms/ml on the average 30 minutes after administration. The levels of CMX in bone marrow blood exceeded those in the venous blood at 60 minutes and thereafter and CTM at 30 minutes of administration and thereafter. It is therefore considered that both CMX and CTM appear to be useful drugs for the prophylaxis and treatment of bone marrow infection, e.g. osteomyelitis.

Adolescent↗
PubMed1982

[The pharmacokinetic studies on spiramycin and acetylspiramycin in rats].

Spiramycin (SPM) and acetylspiramycin (ASPM) have been known to be potent macrolide antibiotics in vivo, although spiramycins had rather mild antimicrobial activities in vitro. The physiological disposition of SPM and ASPM could participate in their in vivo activities. 14C-labeled SPM-I or 3H-labeled ASPM was administered intravenously in rats (20 mg/kg), and plasma levels, excretion and distribution have been studied. The plasma levels of SPM-I and ASPM were low both in radioactivity and bioactivity. After intravenous administration, 14C-SPM-I was excreted by 48 hours into urine, bile and faeces at the rates of 39.6, 31.4% and 37.1%, respectively. And 27.8% of the dose was recovered into urine by 48 hours after administration of 3H-ASPM. Higher radioactivities were detected in the spleen, kidney cortex, submaxillary gland, liver and lung by whole body autoradiography 1 hour after intravenous administration, and the levels tended to be retained until 24 hours. After intravenous administration at the dose rate of 50 mg/kg, the biological half-lives (T 1/2) of ASPM,SPM-I, josamycin and midecamycin were 151, 103, 71 minutes and 54 minutes, respectively, and the apparent volumes of distribution (V beta) were 9.2, 8.9, 3.6 L/kg and 7.7 L/kg, respectively. From these results, it was suggested that the highest activity observed for ASPM in experimental mice infections might be correlated with high affinity for the tissues and the long biological half-life of ASPM.

Animals↗
PubMed1981

Partial characterization of RNA polymerase II complex released by micrococcal nuclease digestion of rat liver nuclei.

Two forms of RNA polymerase II were released from rat liver chromatin by micrococcal nuclease digestion of the nuclei. One from behaved like a free RNA polymerase II and the other like a complex with other nuclear components. Both forms of RNA polymerase II activity were recovered in the 0.16 M NaCl-soluble fraction of the nuclear digest, and the complexed from the RNA polymerase II could transcribe its endogenous template under conditions permitting only of elongation of the RNA synthesis. The RNA polymerase II complex was further purified by gel filtration chromatography and column electrophoresis. Analysis of protein and DNA of the partially purified complex suggested that the RNA polymerase II was bound to mono- or dinucleosomes carrying some characteristic nonhistone proteins. Furthermore, in experiments on tissues from starved rats, the two forms of RNA polymerase II were found to originate from different functional states of the chromatin-bound enzyme in vivo.

Animals↗
PubMed1981

Postmortem changes in the actin-myosin interaction of rabbit skeletal muscle.

Postmortem changes in the actin-myosin interaction were studied by determining the amount of thick and thin filaments dissociated by ATP. The amount of separated filaments was very small in myofibrils prepared from muscles in rigor, while it increased markedly during post-rigor storage of muscles. Electron microscopically, separated thick and thin filaments prepared from stored muscles were similar to freshly prepared ones and no signs of proteolytic degradation of either type of filament could be observed. A protein which was released from myofibrils (probably from Z discs) on Ca2+-treatment seemed to be most closely related to the post-rigor dissociation of thick filaments from thin filaments.

Actins↗
PubMed1981

Preparation of a new fluorescent analog of ATP, 2'-(5-dimethylaminonaphthalene-1-sulfonyl)amino-2'-deoxy ATP, and its interactions with myosin and actomyosin.

A fluorescent ATP analog, 2'-(5-dimethylaminonaphthalene-1-sulfonyl)amino-2'-deoxy ATP (DNS-ATP), was synthesized. In water, the wavelengths of maximum excitation were 260 and 340 nm, and that of maximum emission was 554 nm. The fluorescence quantum yield with excitation at 340 nm was 0.052. In 80% dioxane-20% water solution, the wavelength of the maximum emission shifted to 527 nm and the quantum yield was about 5.4 times in water. When DNS-ATP was mixed with HMM in the presence of Mg2+ ions, the fluorescence intensity of DNS-ATP was enhanced by about 30%, and the wavelength of maximum emission shifted to 545 nm. The observed second-order rate constant for the change in fluorescence intensity after adding DNS-ATP to HMM was 1.6 x 10(-7) M-1 . s-1, while the observed first-order rate constant for its recovery was 0.17 s-1. When the HMM DNS-ATPase reaction was measured in terms of the TCA-Pi liberation, 1 mol of initial burst of Pi liberation per mol of myosin was observed. In 50 mM KCl and at 20 degrees C, the rate of the HMM DNS-ATPase reaction was increased by F-actin from 0.4 to 1.15 s-1 (in 3 mg/ml F-actin). The observed dissociation constant for the binding of DNS-ATP with HMM increased from 1.2 to 20 microM in the presence of 5 mg/ml F-actin. However, the extent of change in fluorescence intensity at infinite concentration of DNS-ATP was unaffected by the presence of F-actin.

Actomyosin↗
PubMed1981

5'-terminal nucleotide sequence of the messenger RNA coding for bovine corticotropin/beta-lipotropin precursor.

The complete 5'-terminal nucleotide sequence of the MRNA coding for the bovine common precursor of corticotropin and beta-lipotropin has been determined. The 5'-32P-labelled, 21-nucleotides-long, single-stranded DNA fragment complementary to a portion of the 5'-noncoding region of the mRNA was prepared from a cDNA clone and elongated by reverse transcriptase reaction with the mRNA as template. The DNA transcript formed was sequenced by the procedure of Maxam and Gilbert, and the resultant sequence was cross-checked by two-dimensional electrophoretic analysis of the partial alkaline digest of the 5'-32P-labelled mRNA. The 5'-terminal nucleotide residue was determined by two-dimensional thin-layer chromatography of the complete hydrolysis product of the 5'-32P-labelled mRNA. The nucleotide sequence determined, which partially overlaps the known sequence of the cloned cDNA, reveals the complete 5'-terminal sequence of the mRNA. This, in conjunction with our previous data, defines the complete primary structure of the mRNA. The mRNA is composed of 1098 nucleotides, including an unusually long 5'-noncoding sequence of 128 nucleotides. The presence of a 'cap' structure at the 5' terminus of the mRNA is suggested. The 5'-terminal 48 nucleotide residues of the mRNA are extremely purine-rich, having an A + G content of 83%, whereas all pyrimidine-rich segments are located downstream from there. Because the 5'-noncoding region of the mRNA contains three segments of potential secondary structure which partially overlap, it can exist in a number of alternative base-pairing configurations. However, its interaction with the 3'-terminal segment of 18-S rRNA at the site of maximal complementarity would fix the mRNA configuration in such a way as to bring the possible site of ribosome binding near the initiation codon.

Adrenocorticotropic Hormone↗
PubMed1981

Effect of DNA on thyroid-hormone binding by specific receptor proteins from rat-liver nuclei.

Influence of double-stranded native DNA on the binding of thyroid hormone, 3,5,3'-triiodo-L-thyronine, by the isolated nuclear receptors was studied and the following results were obtained. (1) The receptor-triiodothyronine complexes bound to DNA with moderate affinities. (2) DNA enhanced the hormone binding of the receptors. (3) The stimulatory DNA effect on triiodothyronine binding of the receptors was dependent on DNA concentration, showing its maximum at 30 microgram/ml. (4) The increase in triiodothyronine binding was observed not only in the initial velocity but also in the plateau level which was attained after sufficient incubation time. (5) There were two types of specific receptors in the rat liver nuclear extract. The dissociation constants and the maximal binding capacities for triiodothyronine, which were determined by Scatchard plot analysis in the presence and absence of DNA, suggested that DNA exerted its effect through increasing binding capacity on one class of the receptors and through enhancing affinity for the hormone on the other class of the receptors. (6) Among various polynucleotides examined, the double-stranded eukaryotic DNA was most effective in enhancing the hormone binding by the receptors. These results indicate that the nuclear thyroid hormone receptors interact with double-stranded DNA in a specific manner and are induced to bind more thyroid hormone. We interpret these results as suggesting that a ternary complex of triiodothyronine, the receptor and DNA is formed in the cell nucleus in vivo, probably representing an intrinsic step in the hormone action. Possible physiological significance of this effect of DNA on the receptors is discussed.

Animals↗
PubMed1981

Mode of reactions between xanthine oxidase and aromatic nitro compounds.

The electron transfer mechanism in the reduction of aromatic nitro compounds by xanthine oxidase was investigated using methyl p-nitrobenzoate and p-nitroacetophenone as substrates. Methyl p-nitrobenzene was reduced by both one-electron and more than two-electron transfer mechanisms in the enzyme-electron donor system. When NADH was used as an electron donor, the ratio of one-electron flux to the total electron flux (the summation of one-electron and more than two-electron fluxes) was dependent on pH of the medium, but not on the concentration of the nitro compounds. The reverse was the case when the electron donor was xanthine. Additional experiments showed that methyl p-nitrobenzoate or p-nitroacetophenone was reduced to the corresponding hydroxylamino compounds and amino compounds by xanthine oxidase supplemented with xanthine or NADH. In these cases, the pattern of formation of the reduction products was dependent on the enzyme activity. The present study strongly suggested that the reduction of aromatic nitro compounds by xanthine oxidase proceeds through the four-electron and six-electron transfer mechanisms as well as the one-electron transfer mechanism.

Acetophenones↗
PubMed1981

[Bombesin effects on the lateral hypothalamic and gastric acid secretory system in the rat (author's transl)].

Gastrosecretory effects of intravenous administration, and microinjection and electro-osmotic application into the lateral hypothalamus (LHA) were investigated in the case of bombesin, alone and concomitant administration with insulin or 2-deoxy-D-glucose (2-DG). Bombesin, a tetradecapeptide found in the brain and gastrointestinal tract of mammals, is a potent gastrin releasing factor. At doses below the threshold of gastric secretion, bombesin produced a decrease in latency and an increase in the amount of insulin-induced gastric acid secretion. In the LHA, microinjections and electro-osmotic applications had similar effects but did not affect secretion when given alone, yet reduced the latency and increased the amount of insulin-induced acid secretion. LHA neuronal activity was also unaffected by electro-osmotic application of bombesin alone, but this compound enhanced the excitatory effects of both insulin and/or 2-DG. Thus, the gastric secretory effects of bombesin appear to be local. This peptide modulates LHA-gastrosecretory mechanism but it is ineffective when administered alone.U

Animals↗