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Biomedical subjects

K Okano

Publications and source records attributed to K Okano.

At least 163 records · Page 9Linked to original sources
PubMed1992

Hapten synthesis for (+)-6-(2-chlorophenyl)-3-cyclopropanecarbonyl-8,11-dimethyl-2,3,4,5-tet rahydro-8H-pyrido[4',3':4,5]thieno[3,2-f] triazolo[4,3-a][1,4]diazepine (E6123).

(+)-6-(2-Chlorophenyl)-3-cyclopropanecarbonyl-8,11-dimethyl-2,3,4, 5-tetrahydro-8H-pyrido[4',3':4,5]thieno[3,2-f]triazolo[4,3-a] [1,4]diazepine (E6123) is a very potent platelet-activating factor (PAF) receptor antagonist and shows potent anti-PAF activities at the microgram level in a variety of animal models. In order to examine the pharmacokinetics of E6123 at low doses, establishment of a radioimmunoassay is required. On the basis of the metabolic pattern of E6123, we synthesized 6-[2-chloro-4-(3-carboxypropyl) phenyl]-3-cyclopropanecarbonyl-8,11-dimethyl-2,3,4,5-tetrahydro-8H -pyrido[4',3':4,5]thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine 22 as a potential hapten. In the synthesis of 22, we developed butynyl carbamate as a piperidine ring N-protecting group to prevent possible side reaction, namely oxidation of the methylene at position 2. This protecting group is stable under usual basic and acidic conditions.

Azepines↗
PubMed1992

[The sensitivity and specificity of various peroxidase stains--the difference between DAB and 3AC stainings].

FAB Cooperative Group has cited 3 or higher percentage in the peroxidase (PO) activity as one of criteria for the diagnosis of acute myeloid leukemia. We have previously reported in two cases of acute myelomonocytic leukemia (M4) that there was a great difference between 3,3'-diaminobenzidine (DAB) and 3-amino 9-ethyl carbazole (3AC) as substrates for PO reaction. In order to confirm the previous result, we extended the cases and compared the PO activities in blood films taken from several leukemic subjects, which were fixed with various kinds of fixatives, using DAB and 3AC as substrates. Their peroxidase activities were also determined through electron microscopy (EM-PO). There were no differences among fixatives and substrates in staining normal granulocytic cells (neutrophils and monocytes) and cells in 13 cases of leukemia, except for two cases, one with M4 and the other with relapse of M2. These showed the highest PO activity with 3AC staining and 10% formaldehyde acetone buffer for fixation. Besides, all types manifested the highest positivity in EM-PO, except for the relapse of M2 that showed a higher positivity in the peroxidase stain by 3AC staining, 10% formaldehyde acetone buffer fixation than the EM-PO. Unlike other leukemic blasts PO reaction products of blast cells of the two cases showed a scattered distribution of microscopic granules. These findings suggested the difference, which was seen in the previous reports, of the PO stain between two substrates might be due not only to sensitivity for staining but to the presence of some heterogeneity such as isoenzyme in the myeloperoxidase.

3,3'-Diaminobenzidine↗
PubMed1992

[Immunological detection of fecal occult blood-follow up study on patients with positive testing].

To evaluate its clinical utility in the early detection of colorectal diseases, we carried out the immunological fecal occult blood test in 922 patients and monitored the clinical course of the 87 patients in whom it was positive. Thirty-five (40.2%) of these patients underwent subsequent X-ray and colonoscopy, and colorectal cancer was detected in 8 (20%). Our findings confirm the clinical usefulness of this test.

Colorectal Neoplasms↗
PubMed1992

[Metabolite of 15-p-iodophenyl-3(R,S)-pentadecanoic acid (123I) in blood and urine].

We analyzed metabolites of 123I-BMIPP in blood and urine using rats, rabbits and human, while human samples were obtained from normal volunteers of Phase I clinical study. We estimated metabolic pathway of 123I-BMIPP as a myocardial metabolic imaging agent. Radioactivity accumulated in heart after administration gradually decreased and was mainly excreted to bladder via kidneys. The main radioactive component in blood was 123I-PIPA for any species and the urinary components were metabolic conjugates of 123I-PIPA. As results of these studies, we considered that 123I-BMIPP was metabolized to 123I-PIPA by alpha-oxidation process for the first step, follow by beta-oxidation process, then 123I-PIPA was released to blood from tissues. Moreover, 123I-PIPA in blood was conjugated with other compounds and excreted to the bladder.

Animals↗
PubMed1991

The weak calcemic vitamin D3 analogue 22-oxacalcitriol suppresses the production of tumor necrosis factor-alpha by peripheral mononuclear cells.

The effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and its analogue 22-oxacalcitriol (OCT), which was reported to have very weak bone resorbing activity, on the production of tumor necrosis factor (TNF)-alpha was investigated. Mononuclear cells (MNC; 10(6)/ml) were incubated in 5% FCS/RPMI-1640 medium containing 1 microgram/ml lipopolysaccharide (LPS) in the presence or absence of 10(-8) M 1,25(OH)2D3 or 10(-8) M OCT for up to 96 h. Both 1,25(OH)2D3 and OCT suppressed TNF-alpha release by LPS-stimulated mononuclear cells, from the early to late stage of the incubation period, while neither 1,25(OH)2D3 nor OCT shifted the peak time point of TNF-alpha release clearly. MNC (10(6)/ml) were incubated with 1 microgram of LPS in the presence of various concentrations of 1,25(OH)2D3 or 10(-8) M OCT for 48 h. 1,25(OH)2D3 reduced TNF-alpha levels of LPS-stimulated MNC culture supernatant at 48 h in a dose-dependent manner. The half-maximal dose (ED50) for this suppressive effect was 3.7 x 10(-9) M. OCT decreased TNF-alpha levels of culture supernatant at 48 h with a half-maximal dose of 7.8 x 10(-11) M, which indicates that it is approximately 50 times more potent than that of 1,25(OH)2D3. These results indicate that OCT may be applicable as an immunosuppressive agent with limited calcium metabolic activity.

Adult↗
PubMed1991

Identification of a novel CYP2D6 allele associated with poor metabolism of sparteine in a Japanese population.

The relationship between genotypes associated with restriction fragment length polymorphisms at the P450 CYP2D locus and the metabolic phenotypes for sparteine in healthy Japanese subjects was investigated. Four distinct restriction fragments of 44 kb, 29 kb, 11.5 kb or 16 + 9 kb after digestion with Xba I were observed. The genotype of Xba I 11.5 kb, which is predictive of the poor metabolizer phenotype in Caucasians is also associated with Japanese poor metabolizers. Most Xba I 44 kb are associated with the extensive metabolizer phenotype. However, one Xba I 44 kb haplotype in linkage disequilibrium with a Bam HI restriction fragment length polymorphism allele, designated Bam HI 2.3 kb-, appears to be a novel mutant CYP2D6 allele in Japanese subjects having the poor metabolizer phenotype.

Adolescent↗
PubMed1991

Structure-activity studies on triazolothienodiazepine derivatives as platelet-activating factor antagonists.

A series of triazolodiazepines was synthesized and evaluated for anti-platelet activating factor (PAF) activities. Structure-activity relationship (SAR) studies on this series revealed that the introduction of a methyl group into the 8-position of the thienodiazepine nucleus can lead to a lengthening of the duration of action. Introduction of a methyl group produced an asymmetric center and the enantiomers so formed were separated with an optical resolving column. In the in vitro assay system, the (+)-isomers displayed 50-200 times more potent anti-PAF activity than the (-)-isomers. After comparison of toxicology and pharmacokinetics, (+)-6-(2-chlorophenyl)-3- cyclopropanecarbonyl-8,11-dimethyl-2,3,4,5-tetrahydro-8H-pyrido[4' ,3':4,5]thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine (35(+)-isomer, E6123) was selected from among the compounds synthesized as a candidate for clinical study.

Animals↗
PubMed1991

Time course of changes in brain energy metabolism of the rat after microsphere-induced cerebral embolism.

The present study was designed to elucidate pathophysiological changes in the brain energy metabolism after cerebral ischemia. Cerebral ischemia was induced in rats by administering microspheres into the right carotid canal, and the time course of changes in cerebral energy metabolism was examined up to the 7th day after the operation. Approximately 50% of the operated rats revealed typical symptoms of stroke. In the right hemisphere, cerebral ATP and creatine phosphate of the rat on the 1st to 7th day were greatly reduced by the microsphere-induced cerebral embolism (maximally 52 and 61%, respectively), whereas the tissue lactate level was increased on the 1st, 3rd and 5th day after the embolism (maximally 125%), suggesting an induction of microsphere-induced cerebral ischemia. These changes in the tissue metabolites were accompanied by a decrease in the mitochondrial oxidative phosphorylation measured in the presence of succinate. A similar trend in the changes of biochemical markers was observed in the left hemisphere, but to a lesser degree or to an insignificant degree. The pathophysiological alterations in behavior and cerebral metabolism of microsphere-injected rats tended to return toward the normal levels on the 7th day after the operation. The results provided information on a useful model for therapeutic studies of anti-ischemic agents in the brain.

Adenosine Triphosphate↗
PubMed1991

[A case report of primary malignant fibrous histiocytoma of the lung].

In this paper, a case of a 59-year-old female of primary malignant fibrous histiocytoma (MFH) of the lung is reported. The patient, who had dyspnea as a main complaint, presented with an abnormal shadow in the chest about 20 years ago, and rapid increase of the shadow has been recognized from one year ago. A pulmonary tumor of the left upper lobe was diagnosed by chest CT, bronchography, pulmonary arteriography. A left pneumonectomy was performed and metastases in lymph nodes and pleural dissemination were recognized. The tumor was 11 X 8 X 6 cm, white, multiple nodular, and solid with a clear border. Histologic examination showed the storiform pleomorphic type of MFH mixed with fibroblastoid cells and histiocytoid cells. Ga scintigram, bone scintigram, and CT conducted before and after the surgery did not show metastasis, but the patient died due to respiratory insufficiency caused by metastasis to the right pleura at 9 months after surgery.

Female↗
PubMed1991

Naftidrofuryl oxalate improves impaired brain glucose metabolism after microsphere-induced cerebral embolism in rats.

The present study was designed to elucidate possible therapeutic effects of naftidrofuryl on the brain glucose metabolism after cerebral ischemia. Cerebral ischemia was induced by injecting 680 microspheres with a diameter of 48 microns into the right internal carotid artery of the rat. After ensuring the onset of symptoms of stroke on the first day after the operation, the rats were treated with intraperitoneal injections of 15 mg/kg naftidrofuryl oxalate twice a day. The behavioral and metabolic changes of operated rats were monitored up to the 5th day after surgery. The symptoms gradually faded away, from the 3rd day on, after microsphere-induced cerebral embolism. Tissue glucose and glycogen greatly increased after cerebral embolism, suggesting embolism-induced inhibition of glycolysis. To elucidate which steps in the glycolytic catabolism are inhibited after cerebral ischemia, biochemical activities of the glycolytic enzymes in the Embden-Meyerhof pathway and tricarboxylic acid cycle were determined on the 3rd day after surgery. Enzyme activities of hexokinase, phosphofructokinase and pyruvate kinase were not inhibited, but rather increased slightly after cerebral embolism. Malate dehydrogenase activity in the brain mitochondria was markedly increased after microsphere-embolism, whereas other enzyme activities in the tricarboxylic acid cycle were never inhibited by the cerebral embolism. Treatment of naftidrofuryl resulted in an appreciable reverse of the brain glucose and glycogen levels and a substantial recovery of altered enzyme activities to normal levels in the Embden-Meyerhof pathway and tricarboxylic acid cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Functional expression of human leukocyte elastase (HLE)/medullasin in eukaryotic cells.

We have cloned a full length cDNA for human leukocyte elastase (HLE, EC 3.4.21.37)/medullasin from the cDNA library of human leukemic cell line, ML3. Recombinant plasmid for the expression of HLE cDNA in eukaryotic cells was constructed in which HLE cDNA was fused in a frame to a leader sequence of human interleukin-2 (IL-2). COS-1 cells, transfected with the plasmid, secreted fusion protein consists of N-terminal 8 amino acid (aa) residues of human IL-2 and 238 aa residues of HLE. As the fusion protein was designed to be connected through lysine residue, elastase activity was generated after digestion of the fusion protein with lysyl-endopeptidase.

Amino Acid Sequence↗
PubMed1990

Effects of a novel PAF antagonist, E6123, on PAF-induced biological responses.

E6123 is a new member of the benzodiazepine class of PAF antagonists. Although it has similar activity in vitro to the two representative antagonists WEB2347 and Y24180, in vivo it is far more active than these compounds. Thus E6123 was effective in inhibiting dose-dependently PAF-induced bronchoconstriction when administered orally or intravenously (IC50 1.0 and 1.3 micrograms/Kg, respectively, at 3 hr), and had a minimum effective dose of 10 micrograms/Kg and 3 micrograms/Kg, respectively, against PAF-induced hematoconcentration and edema at 3 hr after oral administration. Furthermore, E6123 protects mice from PAF-induced death dose-dependently (ED50 7 micrograms/Kg at 3 hr). In conclusion, E6123 should prove valuable in pharmacological and clinical research into the roles of PAF, and in therapy of diseases such as asthma, in which PAF is assumed to play a pathological role.

Animals↗
PubMed1990

Effects of a novel PAF antagonist, E6123, on passive anaphylaxis.

E6123 inhibited antigen-induced bronchoconstriction, the development of bronchial hyperreactivity and eosinophil infiltration in the airway in passively sensitized guinea pigs and protected mice from anaphylactic death. The inhibitory effects of E6123 on anaphylactic response were very potent compared with those of WEB 2347 and Y-24180.

Anaphylaxis↗
PubMed1990

An ADPase-like substance in placental extracts.

The inhibitory effect of human placenta on ADP-induced platelet aggregation was examined. Placental extracts were purified by chromatography and gel filtration. The eluted fractions were subjected to affinity chromatography with Bestatin AH-Sepharose to obtain a more purified substance. A substance markedly inhibited platelet aggregation induced by ADP, and also exhibited high placental leucine aminopeptidase (P-LAP) activity. Preincubation of sample with ADP abolished the platelet aggregatory effect. Thin-layer chromatography (TLC) analysis revealed that the substance hydrolyzed ADP to AMP. The potent anti-platelet aggregating activity of placental extracts appears to be due to ADPase-like action. This action may be one of the controlling factors of hemostasis in fetoplacental circulation.

Adenosine Diphosphate↗
PubMed1990

Transient expression of chimeric CAT genes injected into early embryos of the domesticated silkworm Bombyx mori.

In order to establish a transient expression system for genes introduced into early embryos of the silkworm, Bombyx mori, we tested various promoters ligated with CAT reporter genes. The embryos into which we injected supercoiled plasmid DNA of pFb(-860/+10)CAT containing the Bombyx fibroin promoter region ligated to the CAT gene showed a reasonably high CAT activity beginning around 30 h after oviposition. This high activity was observed only when the plasmid was injected before termination of the early nuclear cleavage stage, which was about 8 h after oviposition, but not after this stage. This means that the expression of injected DNA is closely related to the presence of cleavage nuclei in early embryos. Promoters originating from insect genes, like the Bombyx sericin-1 gene, Drosophila hsp70 and Drosophila copia LTR, functioned as strong promoters in the embryos. On the contrary, promoters from mammalian virus genes, such as the SV40 early and Moloney murine leukemia virus LTR genes, functioned as weak promoters. Moreover, linearized DNAs showed no or weak activity of expression in embryos. From these results, we conclude that the silkworm embryo transient expression system is a useful tool for studying the mechanism of regulation of insect genes.

Animals↗
PubMed1990

A case of pseudo-Bartter's syndrome associated with hypergastrinemia, thrombocytosis and increased serum thyroxine-binding globulin.

A housewife, 40 years of age, was admitted with dysesthesia of the extremities, muscle weakness, and attacks of adynamia and thirst. She had been taking a laxative for more than 20 years. On physical examination, blood pressure was 94/56 mmHg. Laboratory tests revealed thrombocytosis, low serum K and marked increases in both plasma renin activity and serum aldosterone. Serum TBG was increased. Serum gastrin was also markedly increased and could not be enhanced by exogenous secretin. Both angiotensin 11 loading test and noradrenalin loading test failed to increase blood pressure. Ammonium chloride loading to examine the disturbance of urinary acidification was abnormal in the short term test and borderline in the long term test. Following a diagnosis of pseudo-Bartter's syndrome induced by long term intake of laxative and repeated diarrhea, the administration of laxative was interrupted and potassium, indomethacin and spironolactone were administered. However, serum K remained low. Hypergastrinemia, thrombocytosis and a high serum TBG level also persisted, the causes of which remain unknown. This is the first reported case of pseudo-Bartter's syndrome associated with hypergastrinemia, thrombocytosis and increased serum TBG.

Adult↗