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Biomedical subjects

N Murakami

Publications and source records attributed to N Murakami.

At least 199 records · Page 11Linked to original sources
PubMed1996

Incidence of anaerobic infections among patients with pulmonary diseases: Japanese experience with transtracheal aspiration and immediate bedside anaerobic inoculation.

We conducted a study to assess the precise incidence of anaerobic infections among patients with pulmonary diseases in Japan. To avoid false-negative results of anaerobic cultures, we used percutaneous transtracheal aspiration and subsequent immediate bedside anaerobic inoculation onto a set of plates with appropriately selected culture media. Fifty-six episodes of pulmonary disease occurred in 50 patients; anaerobes were isolated in 20 (36%) of these episodes. Bacteria were recovered in 30 (94%) of 32 episodes not associated with prior antimicrobial therapy, and anaerobes were isolated in 15 (47%) of these 32 episodes. Rates of anaerobic isolation in episodes of pneumonia (7 of 14), lung abscess (3 of 3), and acute exacerbation of chronic lower respiratory tract infection (5 of 15) that were not associated with prior antimicrobial therapy were 50%, 100%, and 33%, respectively.

Bacteria, Anaerobic↗
PubMed1996

Mesial temporal lobe epilepsy in childhood.

To clarify the clinical picture of mesial temporal lobe epilepsy (MTLE) in childhood, we carried out a clinical, electroencephalographic, and neuroradiologic study of 19 patients. MTLE was noted in 19 (0.82%) of 2,319 epileptic patients with childhood onset. Three types of initial seizure were recognized: febrile convulsion, afebrile generalized convulsion, and complex partial seizure (CPS). As presumed causes, various prolonged convulsions (persisting for > 30 min) were found in 12 (63.2%) cases. Regardless of the presence of preceding convulsions (febrile or afebrile), the clinical course was not uniform, with CPS in the early period temporarily controlled in some cases and intractable from the early period in others. Unilateral hippocampal abnormalities were confirmed on magnetic resonance imaging (MRI) before the age of 5 years in two cases, suggesting that mesial temporal sclerosis (MTS) is formed within a relatively short period in some cases. Seizures were controlled for > 6 months in only two (10.5%) cases and persisted in 17. In four (21.1%) cases, surgical treatment was considered to be available.

Age Factors↗
PubMed1996

[Analysis of verotoxin-producing Escherichia coli (O157:H7) strains isolated in the Fukuoka area in 1994 by pulsed-field gel electrophoresis].

Nine verotoxin-producing Escherichia coli O157:H7 strains were isolated from 9 pediatric patients with sporadic enteritis between July and September 1994 at four clinics in the Fukuoka area. The patients included two families with two cases each. These strains were analyzed by pulsed-field gel electrophoresis for Xba I-digested DNA fragments. The restriction patterns were identical between each two strains within the two family outbreaks, but different among the seven strains of the distinct seven sporadic cases. It is strongly suggested that the seven sporadic cases were infected through distinct sources, and that the two family cases were due to a common source of infection or person to person infection.

Bacterial Toxins↗
PubMed1996

Plasma and neurohypophyseal content of vasopressin in diabetes mellitus.

Vasopressin (VP) hypersecretion is known to occur in diabetes mellitus. Using magnetic resonance (MR) imaging, we evaluated the VP content of the posterior lobe of the pituitary gland in 22 patients with uncontrolled noninsulin-dependent diabetes mellitus. The mean VP level and hemoglobin A1c value were elevated; 6.8 +/- 6.8 pg/mL (normal, 0.3-3.5) and 11.7 +/- 2.1% (normal, < 6%). The signal intensity ratio of the posterior lobe to the pons was calculated on a MR T1-weighted image where the signal intensity reflects VP content and the posterior lobe has a characteristic hyperintense signal under normal conditions. The mean signal intensity ratio (1.34 +/- 0.22) was lower than that in 20 healthy subjects (1.56 +/- 0.13; P < 0.01). In 7 cases, the signal intensity ration was markedly decreased, and the hyperintense signal was absent. The hyperintense signal appeared after diabetic control in all 6 subjects who underwent follow-up MR examinations within 1-2 months. The VP content in the posterior lobe was decreased in patients with uncontrolled diabetes mellitus, which was thought to be caused by persistent VP hypersecretion. The persistent elevation of plasma VP might have some role in the initiation and progression of diabetic complications.

Adult↗
PubMed1996

Acceleration of glycolysis in erythrocytes by the antidiabetic agent M16209.

The effects of M16209 (1-(3-bromobenzofuran-2-ylsulfonyl)hydantoin), an antidiabetic agent and aldose reductase inhibitor, on glycolysis were studied in rat and human erythrocytes in vitro. M16209 increased lactate production from glucose when incubated with rat and human erythrocytes, and also increased glucose consumption in rat erythrocytes. The rates of production of lactate in rat erythrocytes treated with M16209 at 10, 25 and 50 microM were 113, 118 and 123%, respectively, of those in vehicle treated cells. Sorbinil (aldose reductase inhibitor), tolbutamide (sulfonylurea), and buformine (biguanide) did not increase lactate production in rat erythrocytes when tested at 50 microM. On the other hand, M16209 did not affect lactate production from D-glyceraldehyde in rat erythrocytes. At 100 microM the agent decreased both glucose-6-phosphate and fructose-6-phosphate in rat erythrocytes, and increased fructose-1,6-bisphosphate; at 10 microM it also increased 6-phosphofructokinase activity in rat hemolysates. These findings suggest that M16209 accelerates glycolysis in erythrocytes via activation of 6-phosphofructokinase.

Aldehyde Reductase↗
PubMed1996

Medicinal foodstuff. III. Sugar beet. (1): Hypoglycemic oleanolic acid oligoglycosides, betavulgarosides I, II, III, and IV, from the root of Beta vulgaris L. (Chenopodiaceae).

Betavulgarosides I, II, III, and IV, oleanolic acid oligoglycosides having an unique acidic substituent, were isolated from the root of Beta vulgaris L. (sugar beet) together with betavulgarosides VI, VII, and VIII. The chemical structures of betavulgarosides I, II, III, IV were identified from chemical and physicochemical evidence. Betavulgarosides II, III, and IV were found to exhibit hypoglycemic activity in an oral glucose tolerance test in rats.

Animals↗
PubMed1996

New bioactive monoterpene glycosides from Paeoniae Radix.

Bioassay-guided separation of MeOH extract of Japanese Paeoniae Radix inhibiting contractile responses of guinea pig ileum stimulated with electric field disclosed a new monoterpene glycoside, 6-O-beta-D-glucopyranosyl-lactinolide (1), as an active constituent together with two new monoterpene glycosides (3 and 4) and two new monoterpenes (2 and 5). Furthermore, 1-O-beta-D-glucopyranosyl-paeonisuffrone (2) was found to inhibit histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1996

Bioactive saponins and glycosides. II. Senegae Radix. (2): Chemical structures, hypoglycemic activity, and ethanol absorption-inhibitory effect of E-senegasaponin c, Z-senegasaponin c, and Z-senegins II, III, and IV.

Following the characterization of E-senegasaponins a and b and Z-senegasaponins a and b, new bioactive saponins named E-senegasaponin c and Z-senegasaponin c were isolated from Senegae Radix, the root of Polygala senega L. var. latifolia TORREY et GRAY., together with Z-senegins II, III, and IV. The chemical structures of E and Z-senegasaponins c and Z-senegins II, III, and IV were elucidated on the basis of chemical and physicochemical evidence, and the geometrical isomeric structures of the 4"-methoxycinnamoyl and 3",4"-dimethoxycinnamoyl groups in these saponins were found to show tautomer-like behavior under irradiation with fluorescent lamps. E and Z-Senegasaponins c and E and Z-senegins II, III, and IV were found to exhibit hypoglycemic activity in the oral D-glucose tolerance test. (E) and (Z)-Senegins II also showed an inhibitory effect on alcohol absorption in rats.

Absorption↗
PubMed1996

Antitumor-promoting activities of various synthetic 1-O-acyl-3-O-(6'-O-acyl-beta-D-galactopyranosyl)-sn-glycerols related to natural product from freshwater cyanobacterium Anabaena flos-aquae f. flos-aquae.

1-O-Acyl-3-O-(6'-O-acyl-beta-D-galactopyranosyl)-sn-glycerol, which was isolated from a nitrogen-fixing fresh water cyanobacterium, Anabaena flos-aquae f. flos-aquae, was synthesized by utilizing lipase-catalyzed acylation. The antitumor-promoting activities of these galactolipids were evaluated using a short-term in vitro assay of Epstein-Barr virus activation in Raji cells induced by 12-O-tetradecanoyl- phorbol 13-acetate (TPA). The glyceroglycolipids which have a palmitoleoyl residue at the 1-O-position exhibited more potent activities than the others in this assay.

Anabaena↗
PubMed1996

Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside.

Following the characterization of thunberginols A, B, and F, six bioactive principles, thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-O-glucoside, and (+)-hydrangenol 4'-O-glucoside, were isolated from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, together with four kaempferol and quercetin oligoglycosides. Their chemical structures have been determined on the basis of chemical and physicochemical evidence. Thunberginols C, D, E, and G and (-)-hydrangenol 4'-O-glucoside showed antiallergic activity in the in vitro bioassay using the Schultz-Dale reaction. These components also exhibited inhibitory activities on the histamine release from rat mast cells and on the histamine-induced contraction in isolated guinea pig tracheal chain. In addition, thunberginols C, D, E, and G showed antimicrobial activities against oral bacteria.

Animals↗
PubMed1996

Bioactive saponins and glycosides. III. Horse chestnut. (1): The structures, inhibitory effects on ethanol absorption, and hypoglycemic activity of escins Ia, Ib, IIa, IIb, and IIIa from the seeds of Aesculus hippocastanum L.

Five bioactive triterpene oligoglycosides named escins, Ia, Ib, IIa, IIb, and IIIa were isolated from the seeds of horse chestnut tree, Aesculus hippocastanum L. (Hippocastanaceae). The chemical structures of escins Ia, Ib, IIa, IIb, and IIIa were determine on the basis of chemical and physicochemical evidence, which included selective cleavage of the glucuronide linkage using photochemical reaction and lead tetraacetate decarboxylation reaction. Escins Ia, Ib, IIa, and IIb were found to exhibit an ethanol absorption-inhibitory effect and hypoglycemic activity in the oral glucose tolerance test in rats. Some structure-activity relationships are reported.

Animals↗
PubMed1996

Bioactive constituents of Chinese natural medicines. I. New sesquiterpene ketones with vasorelaxant effect from Chinese moxa, the processed leaves of Artemisia argyi Levl. et Vant.: moxartenone and moxartenolide.

Two new sesquiterpene ketones, moxartenone and moxartenolide, and three octadecadienoic acids were isolated from Chinese moxa, the processed leaves of Artemisia argyi LEVL. et VANT., together with two sesquiterpenes, five triterpenes, two phenyl propanoids and three polyoxyflavones. The chemical structures of new sesquiterpenes, moxartenone, moxartenolide, and octadecadienoic acids were determined on the basis of chemical and physiochemical evidence. Moxartenolide was found to inhibit the contractions induced by a high concentration of K+, by norepinephrine, and by serotonin in isolated aortic strips of rat, while moxartenone showed little activity.

Animals↗
PubMed1996

Bioactive saponins and glycosides. IV. Four methyl-migrated 16,17-seco-dammarane triterpene gylcosides from Chinese natural medicine, hoveniae semen seu fructus, the seeds and fruit of Hovenia dulcis THUNB.: absolute stereostructures and inhibitory activity on histamine release of hovenidulciosides A1, A2, B1, and B2.

Four bioactive methyl-migrated 16,17-seco-dammarane type triterpene glycosides called hovenidulciosides A1, A2, B1, and B2 were isolated from a Chinese natural medicine, Hoveniae Semen Seu Fructus, the seeds and fruit of Hovenia dulcis THUNB. (Rhamnaceae) together with hoduloside III and (+)-gallocatechin. The absolute stereostructures of hovenidulciosides A1, A2, B1, and B2 have been elucidated by chemical and physicochemical evidence. All were found to inhibit the histamine release from rat peritoneal exudate cells induced by compound 48/80 and calcium ionophore A-23187.

Animals↗
PubMed1996

Development of bioactive functions in Hydrangeae dulcis folium. VI. Syntheses of thunberginols A and F and their 3'-deoxy-derivatives using regiospecific lactonization of stilbene carboxylic acid: structures and inhibitory activity on histamine release of hydramacrophyllols A and B.

Lactonization reaction of 2-carboxystilbene mediated by copper(II) chloride proceeded regiospecifically to give the five-membered lactone, while the bromolactonizations using N-bromosuccinimide and anodic oxidation were found to furnish the six-membered lactone. Using these regiospecific lactonization reactions as a key step, antiallergic and antimicrobial isocoumarins and the benzylidenephthalides thunberginols A and F and their 3'-deoxyanalogs were synthesized from phyllodulcin and hydrangenol. Two phthalides called hydramacrophyllols A and B were isolated from Hydrangeae Dulcis Folium and their stereostructures were determined on the basis of physicochemical and chemical evidence, which included the syntheses of hydramacrophyllols A and B from hydrangenol by the application of the lactonization method using copper(II) chloride. In addition, hydramacrophyllols A and B were found to exhibit an inhibitory effect on the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1996

Bioactive saponins and glycosides. V. Acylated polyhydroxyolean-12-ene triterpene oligoglycosides, camelliasaponins A1, A2, B1, B2, C1, and C2, from the seeds of Camellia japonica L.: structures and inhibitory activity on alcohol absorption.

Acylated polyhydroxyolean-12-ene triterpene oligoglycosides, camelliasaponins A1, A2, B1, B2, C1, and C2, were isolated from the seeds of Camellia japonica L. The structures of six camelliasaponins were elucidated on the basis of chemical and physicochemical evidence. Camelliasaponins B1, B2, C1, and C2 were found to exhibit inhibitory activity on ethanol absorption. By comparison of the inhibitory activities for camelliasaponins with those for desacyl-camelliasaponins, acyl groups such as the angeloyl or tigloyl group were found to be essential to exerting the activity.

Animals↗
PubMed1996

Bioactive saponins and glycosides. VI. Elatosides A and B, potent inhibitors of ethanol absorption, from the bark of Aralia elata SEEM. (Araliaceae): the structure-requirement in oleanolic acid glucuronide-saponins for the inhibitory activity.

Potent inhibitors of ethanol absorption, elatosides A and B, were isolated from the bark of Aralia elata SEEM, through bioassay-guided separation together with elatosides C and D and four known oleanolic acid glucuronide-saponins, spinasaponin A, spinasaponin A 28-O-glucoside, and stipuleanosides R1 and R2. The structures of elatosides A, B, C, and D were determined on the basis of chemical and physicochemical evidence as oleanolic acid 3-O-¿[beta-D-xylopyranosyl (1-->2)] [beta-D-galactopyranosyl (1-->3)]¿-beta-D-glucopyranosiduronic acid, oleanolic acid 3-O-¿[beta-D-galactopyranosyl (1-->2)] [beta-D-galactopyranosyl (1-->3)]¿-beta-D-glucopyranosiduronic acid, and their 28-O-glucopyranosyl esters, respectively. The inhibitory effect of various oleanolic acid 3, 28-O-bisdesmosides, oleanolic acid 3-O-monodesmosides, and oleanolic acid on ethanol absorption was examined and it was found that the 3-O-glucuronide moiety and the 28-carboxyl group in oleanolic acid glucuronide-saponin were required to exert the inhibitory activity.

Animals↗
PubMed1996

Bioactive saponins and glycosides. VII. On the hypoglycemic principles from the root cortex of Aralia elata Seem.: structure related hypoglycemic activity of oleanolic acid oligoglycoside.

The hypoglycemic component, elatoside E, was isolated from the root cortex of Aralia elata SEEM. (Araliaceae) together with elatoside F and eight known oleanolic acid glycosides, elatosides A and C, oleanolic acid 3-O-[alpha-L-arabinofuranosyl (1-->4)]-beta-D-glucopyranosiduronic acid, oleanolic acid 3-O-beta-D-glucopyranosiduronic acid, stipuleanosides R1 and R2, and chikusetsusaponins IV and IVa. The structures of elatosides E and F were determined on the basis of chemical and physicochemical evidence as oleanolic acid 3-O-[beta-D-xylopyranosyl (1-->2)][beta-D-glucopyranosyl (1-->3)]-alpha-L-arabinopyranoside and its 28-O-beta-D-glucopyranosyl ester, respectively. The hypoglycemic activity of oleanolic acid and nine oleanolic acid oligoglycosides from the root cortex of Aralia elata was determined by monitoring inhibition effect on the elevation of plasma glucose level by oral sucrose tolerance test in rats, and some structure-activity relationships of oleanolic acid glycoside were obtained.

Animals↗