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Biomedical subjects

N Murakami

Publications and source records attributed to N Murakami.

At least 217 records · Page 12Linked to original sources
PubMed1996

Bioactive constituents of Chinese natural medicines. II. Rhodiolae radix. (1). Chemical structures and antiallergic activity of rhodiocyanosides A and B from the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey. (Crassulaceae).

Two bioactive cyanoglycosides, rhodiocyanosides A and B, and two oligoglycosides, rhodioflavonoside [gossypetin 7-O-beta-D-glucopyranosyl(1-->3)-alpha-L-rhamnopyranoside] and rhodiooctanoside [octyl alpha-L-arabinopyranosyl(1-->6) beta- D-glucopyranoside), were isolated from the Chinese natural medicine "Si Lie Hong Jing Tian" (Shiretsukoukeiten in Japanese), the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey., together with four known compounds: rhodioloside, n-hexyl beta-D-glucopyranoside, gossypetin 7-O-alpha-L-rhamnopyranoside, and tricetin. The chemical structures of new glycosides were determined on the basis of chemical and physicochemical evidence. Rhodiocyanosides A and B exhibited inhibitory activity on the histamine release from rat peritoneal exudate cells sensitized with anti-2,4-dinitrophenyl IgE. Additionally, rhodiocyanoside A, the major constituent of this natural medicine, was also found to show antiallergic activity in a passive cutaneous anaphylaxis test in rat.

Animals↗
PubMed1996

New hypoglycemic constituents in "gymnemic acid" from Gymnema sylvestre.

Investigation of hypoglycemic activity of major saponin constituents from "gymnemic acid", a crude saponin fraction of G. sylvestre, exposed not only two new saponins, gymnemosides a (1) and b (2), but also gymnemoside b and gymnemic acid V (7) as active principles. Furthermore, an acetyl group linked 16- or 22-hydroxy group in 1 and 2 was found to migrate easily to primary 28-hydroxyl group, while acyl migration from 28-hydroxy group in 3 was little observed.

Animals↗
PubMed1996

Medicinal foodstuffs. II. On the bioactive constituents of the tuber of Sagittaria trifolia L. (Kuwai, Alismataceae): absolute stereostructures of trifoliones A, B, C, and D, sagittariosides a and b, and arabinothalictoside.

From the medicinal foodstuff "kuwai", the tuber of Sagittaria trifolia L., four bioactive diterpene ketones, trifoliones A, B, C, and D, two diterpene glucosides, sagittariosides a and b, and a nitroethylphenol glycoside, arabinothalictoside, were isolated, together with six known diterpenes. Their absolute stereostructures were determined on the basis of chemical and physicochemical evidence which included the application of a modified Mosher's method and an exciton chirality method. Among the diterpene constituents, trifoliones A, B, C, and D exhibited inhibitory effects on the histamine release from rat mast cells induced by compound 48/80 and calcium ionophore A-23187.

Animals↗
PubMed1996

[Quality evaluation on Paeoniae radix. I. Quantitative analysis of monoterpene glycosides constituents of Paeoniae radix by means of high performance liquid chromatography. Comparative characterization of the external figures, processing method and the cultivated areas].

The constituents of monoterpene in Paeoniae Radix were analyzed by means of high performance liquid chromatography (HPLC) using hitherto elucidated eight monoterpene glycosides, paeoniflorin 1, oxypaeoniflorin 2, benzoylpaeoniflorin, 3, benzoyloxypaeoniflorin 4, galloylpaeniflorin 5, galloyloxypaeoniflorin 6, albiflorin 7 and lactiflorin 8 and a monoterpene paeoniflorigenone 9. In sixty seven kinds of Paeoniae Radix collected in Japan, China, and South and North Korea those monoterpene constituents 1-9 were found to exist in the amounts of ranging 0.12-9.61% 1, 0.06-10.8% 2, 0.02-0.79% 3, 0.24-0.47% 4, 0.25-2.53% 5, 0.05-2.86% 6, 0.09-2.76% 7, 0.35-0.64% 8 and 0.01-0.49% 9 respectively. In addition, these results obtained by the quantitative analysis were discussed from the viewpoint of the external figures and processing methods.

China↗
PubMed1996

Antinociceptive activity of a novel non-steroidal anti-inflammatory drug (M-5011) with low ulcerogenic effects in mice.

Both analgesic and ulcerogenic activities of d-2-[4-(3-methyl-2-thienyl)phenyl] propionic acid (M-5011), a novel non-steroidal anti-inflammatory drug (NSAID), were compared with those of indomethacin (IND), ketoprofen (KP), diclofenac sodium (DIF), zaltoprofen (ZLT) and tiaprofenic acid (TIA) in mice. All orally administered NSAIDs including M-5011 inhibited kaolin-induced writhing in a dose-dependent manner. M-5011 had an effective antinociceptive activity (ED50 value) of 0.63 mg/kg, being more potent than ZLT (16.80 mg/kg) and TIA (4.78 mg/kg), equipotent to DIF (0.68 mg/kg), and less potent than IND (0.21 mg/kg) and KP (0.28 mg/kg). All drugs tested significantly reduced peritoneal 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) levels at the peak kaolin-induced writhing time (7.5 min post-kaolin injection) without affecting peritoneal bradykinin (BK) levels. Antinociceptive effects of all drugs were closely correlated with inhibition of peritoneal 6-keto-PGF1 alpha levels. Ulcerogenic activities (UD50 value) of M-5011 in the stomach and small intestines were 88.23 and 46.09 mg/kg, respectively. UD50 values of other drugs in the stomach and small intestines were as follows: 8.96 and 4.78 mg/kg, 20.04 and 10.75 mg/kg, 4.19 and 2.24 mg/kg, 62.86 and 46.55 mg/kg, and 110.92 and 54.78 mg/kg for IND, KP, DIF, TIA, and ZLT, respectively. Thus, the safety indexes (UD50/ED50) of the stomach (or small intestine) for M-5011, IND, KP, DIF, TIA and ZLT were 140.05 (73.16), 42.67 (22.76), 71.57 (38.39), 6.16 (3.29), 13.15 (9.74) and 6.60 (3.26), respectively. These findings suggest that M-5011 is a useful NSAID that shows potent antinociceptive effects with low ulcerogenic activities.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Effect of astilbin in tea processed from leaves of Engelhardtia chrysolepis on the serum and liver lipid concentrations and on the erythrocyte and liver antioxidative enzyme activities of rats.

The effects of astilbin in Kohki tea, which is produced from the leaves of Engelhardtia chrysolepis Hance (Chinese name, huang-qui), and of an aglycone of astilbin, taxifolin, on the serum and liver lipid concentrations, and on the erythrocyte and liver antioxidative enzyme activities were determined with rats fed on a cholesterol-free diet. The total liver cholesterol concentration tended to be decreased by feeding with astilbin, and significantly decreased by feeding with taxifolin. The liver phospholipid concentration was decreased by feeding with both astilbin and taxifolin. In addition, astilbin and taxifolin lowered the serum and liver TBARS concentrations, but did not influence the serum and liver antioxidative enzyme activities, suggesting the possibility that these compounds acted to lower the TBARS concentration by their direct antioxidative action in vivo, almost without influencing the antioxidative enzyme activities.

Animals↗
PubMed1996

Melatonin accelerates reentrainment of circadian locomotor activity rhythms to new light-dark cycles in the rat.

We examined whether continuous melatonin administration through subcutaneously implanted silastic tubing accelerates reentrainment of circadian rhythms of locomotor activity to shifted illumination cycles. We found that rats required less time to reentrain to an advanced or delayed phase shift of a light-dark cycle while carrying a silastic implant filled with melatonin than while carrying an empty implant. These results suggest that continuous administration of melatonin accelerates the reentrainment of the circadian locomotor activity rhythm to a new light-dark cycle.

Activity Cycles↗
PubMed1996

A case report of rectal schwannoma.

We experienced a case of rectal schwannoma which was diagnosed before surgery. In this paper we have described this rare case and have discussed a number of similar cases reported in the literature.

Aged↗
PubMed1996

Technetium-99m-sestamibi scintigraphy compared with thallium-201 in evaluation of thyroid tumors.

UNLABELLED: Technetium-99m methoxyisobutylisonitrile (MIBI) is a myocardial perfusion imaging agent that has been reported to effectively localize in various tumors (e.g., lung and thyroid carcinomas and osteogenic sarcoma). To determine its usefulness in thyroid tumors, we compared 99mTc-MIBI with 201TI imaging. METHOD: We evaluated 25 patients with thyroid tumors (papillary carcinoma in 11, follicular carcinoma in 2, follicular adenoma in 7, adenomatous goiter in 5). Fifteen metastatic lesions from differentiated thyroid carcinomas were also evaluated. Early (10 min after injection) and delayed images (120 min after injection) were obtained for both 99mTc-MIBI and 201TI scintigraphy. RESULTS: The early images showed very similar findings for both 99mTc-MIBI and 201TI. However, the delayed images showed that malignant tumors tended to retain more tracer agent than benign nodules. Marked retention was in 61.5% (8 of 13) of 201TI images and 53.8% (7 of 13) of 99mTc-MIBI images. For metastatic lesions from thyroid carcinomas, the findings for 99mTc-MIBI imaging were nearly identical to those for 201TI imaging. A slight difference in clarity was seen that may have been due to the effect of the 99mTc. CONCLUSION: Although 99mTc-MIBI scintigraphy does not have particularly good results in differentiating malignant from benign thyroid tumors, it may be useful in evaluating metastases or predicting recurrence because of its better imaging characteristics.

Adenocarcinoma, Follicular↗
PubMed1996

[Transformation of aplastic anemia to acute myeloid leukemia with myelofibrosis following treatment with granulocyte colony-stimulating factor and erythropoietin].

A 67-year-old female was admitted with fatigue. Peripheral blood examination showed severe pancytopenia. Bone marrow biopsy revealed hypoplastic marrow. She was diagnosed as having aplastic anemia. Steroid pulse therapy was not effective. After treatment with erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF), blasts which were positive for CD13, CD33, CD34 and HLA-DR and negative for myeloperoxidase appeared in the peripheral blood. At this time, bone marrow biopsy revealed myelofibrosis with increased blasts. Chromosome analysis showed 46XX, add (1) (p36), add (1) (q44), -2, -5, del (7) (q11), -12, +3mar. She died of pneumonia despite chemotherapy with etoposide. Administration of EPO and G-CSF may have led to the rapid development of leukemia and myelofibrosis.

Aged↗
PubMed1996

Postoperative bile peritonitis caused by division of an aberrant bile duct in the left triangular ligament of the liver.

A 61-yr-old man underwent Billroth I gastrectomy for an advanced cancer in the corpus of the stomach. On the first postoperative day, fresh bile discharged from the penrose drains, which had been placed in Winslow's foramen, and the volume of bile discharge subsequently increased. Leakage from the gastroduodenal anastomosis was excluded by gastroduodenography. Exploratory relaparotomy showed bile peritonitis with much more bile retention in the left subphrenic space. The origin of bile leakage could not be traced despite close examination of all the extrahepatic biliary tract and the liver surface. Intraoperative cholangiography through the cystic duct after cholecystectomy revealed that the bile leakage originated from an aberrant bile duct present in the free edge of the left triangular ligament (appendix fibrosa hepatis), which had been unintentionally cut at the primary operation. Knowledge of this anatomical structure is important and proper ligation is recommended when dissecting the appendix fibrosa hepatis to avoid postoperative bile peritonitis and the need for a relaparotomy.

Bile↗
PubMed1996

[Postoperative continuous epidural infusion of morphine in a patient with myotonic dystrophy].

Patients with myotonic dystrophy present potential problems during and after anesthesia, especially respiratory dysfunction. A 42-year-old female with myotonic dystrophy associated with slight impairment of respiratory functions and muscular power, underwent abdominal total hysterectomy under epidural anesthesia uneventfully. To relieve pain after the surgery, a bolus of epidural morphine 2 mg was administered through an indwelling lumbar (L1-2) epidural catheter 30 minutes prior to the end of the surgery and followed with continuous epidural infusion of morphine at a rate of 0.083 mg.h-1 using a balloon (Multiday Infuser, Baxter) for three days. She obtained adequate analgesia after the surgery without respiratory depression or other major complications. We demonstrated that the continuous epidural infusion of morphine in a patient with myotonic dystrophy is safe and adequate for postoperative pain relief.

Adult↗
PubMed1996

[Significance of 5'-deoxy-5-fluorouridine (5'-DFUR) administration before surgery for advanced gastric and colonic cancers--activity of pyrimidine nucleoside phosphorylase (PyNPase) and serum immunosuppressive acidic protein (IAP)].

We administered preoperatively 5'-deoxy-5-fluorouridine (5'-DFUR) for treatment of advanced gastric and colonic cancers, and measured pyrimidine nucleoside phosphorylase (PyNPase) in the excised tumor sample and serum immunosuppressive acidic protein (serum IAP), which is an index of the immunity of host-bearing cancer, while studying its direct antitumor effect and improved immunity. Patients with 24 advanced gastric cancers and 36 colonic cancers were randomly divided into a preoperatively administered group and a non-administered group. In the preoperatively administered group, 5'-DFUR (1,200 mg/day) was orally administered on preoperative days 7 approximately 14. After collecting samples (about 0.5 g) from adjacent normal tissues with tumor within 30 minutes after extirpation of tumor and freezing those less than -20 degrees C, the PyNPase level was measured as soon as possible. Moreever, serum IAP levels at pre-administration in the administered group and on admission in the non-administered group were measured. Those in the administered group were measured again on the operative day. No decreasing tendency of PyNPase was generally found in cases with gastric colonic cancers, and no significant difference in stage-II was not either. However, a decreasing tendency in tumor activity was found by pre-administration. Moreover, there was significant improvement in the serum IAP level in cases with gastric and colonic cancers by pre-operative administration of 5'-DFUR. This tendency was also found in advanced colonic cancer with Dukes-C by Dukes's classification. In conclusion, it was suggested that the pre-operative administration of 5'-DFUR for treatment of advanced gastric and colonic cancers has a favorable influence for prognosis because the tumor region was retarded by the high PyNPase activity according to the severity of tumors and elevating tendency of the immune response in host.

Administration, Oral↗
PubMed1996

Phosphoinositide-dependent in vitro phosphorylation of profilin by protein kinase C. Phospholipid specificity and localization of the phosphorylation site.

Phosphoinositides bind to profilin and regulate actin-based cytoskeletal protein assembly. We report here that profilin is phosphorylated in vitro by protein kinase C (PKC) in the presence of phosphoinositides and micromolar concentrations of calcium. PKC-mediated phosphorylation of profilin was observed only in the presence of phosphoinositides; phosphatidylserine and diacylglycerol (known activators of PKC) and other lipids, including phosphatidic acid and phosphatidylglycerol phosphate, did not activate the phosphorylation. The activation of PKC-mediated phosphorylation of profilin by phosphoinositides was as follows: phosphatidylinositol (PI) 4-phosphate (K(m) = 18 microM) > PI 4,5-bisphosphate (K(m) = 30 microM) > PI (no activation). About 0.5 mol phosphate was incorporated per mol of profilin. Phosphorylation of profilin by PKC was not affected by the presence of various concentrations of actin. Phospho-amino acid analysis showed serine to be the only amino acid phosphorylated. The amino acid sequence of a phosphopeptide from CNBr-digested profilin corresponded to the COOH-terminal peptide of profilin (Ala-Ser-His-Leu-Arg-Ser-Gln-Tyr). Further digestion of this phosphopeptide by trypsin generated two phosphopeptides (Arg-Ser-Gln-Tyr and Ser-Gln-Tyr), thereby confirming that the phosphorylation site was the antepenultimate Ser (Ala-Ser-His-Leu-Arg-Arg-Ser(P)-Gln-Tyr).

Actins↗
PubMed1995

Phospholipid binding, phosphorylation by protein kinase C, and filament assembly of the COOH terminal heavy chain fragments of nonmuscle myosin II isoforms MIIA and MIIB.

Previously, we showed that myosin II heavy chains bind to phosphatidylserine (PS) liposomes via their COOH terminal regions and that protein kinase C (PK C) phosphorylates the PS-bound heavy chains [Murakami et al. (1994) J. Biol. Chem. 269, 16082-16090]. In this report, we studied the phospholipid binding, the kinetics of phosphorylation by PK C, and the effect of PK C-mediated phosphorylation on assembly using 46-47 kDa fragments from the COOH termini of macrophage (MIIAF46) and brain type (MIIBF47) heavy chain isoforms. Binding of the fragments to PS or phosphatidylinositol liposomes increased turbidity, but MIIAF46 gave higher turbidity than MIIBF47. Both fragments were sedimented similarly by ultracentrifugation in PS concentration and mole percent of PS dependent manners. With mixed PS/phosphatidylcholine (PC) liposomes, at least 70 mol % PS was required for heavy chain binding. A similar level of PS was required for phosphorylation of fragments by PK C, indicating that binding of tail regions to PS is a prerequisite for phosphorylation by PK C. PK C phosphorylated MIIBF47 with Vmax values 4-5 times higher than those of MIIAF46, but the Km values for the two substrates were similar. The apparent Km values for PS liposomes (Klipid) were also similar for phosphorylation of both isoforms. Mixing PS with PC increased the Klipid and reduced the Vmax values but did not alter the Km values for the substrates. Assembly of MIIBF47, but not MIIAF46, was significantly inhibited by the phosphorylation, indicating that nonmuscle myosin assembly can be regulated, in an isoform specific manner, via phosphorylation of heavy chains by PK C.

Animals↗
PubMed1995

Inhibitor of protein synthesis phase-shifts the circadian oscillator and inhibits the light induced-phase shift of the melatonin rhythm in pigeon pineal cells.

Our recent study showed that dissociated pigeon pineal cells expressed a circadian oscillation of melatonin release which entrained to light-dark cycle and persisted under constant darkness in vitro, suggesting that pigeon pineal cells contain the circadian oscillator and photoreceptors. Six-hour pulses of anisomycin, an inhibitor of protein synthesis that acts at hte 80S ribosomal subunit, induced steady state and phase depended phase shifts of the circadian oscillation of melatonin release. The phase advances and delays were produced at CT 7.9 h and between CT 18.6 h and CT 4.5 h, respectively. The magnitudes of phase shifts were dose dependent and correlated with the magnitudes of inhibition of protein synthesis determined at CT 4.5 h. Furthermore, anisomycin blocked the light-induced phase advance. Two dimensional electrophoresis revealed that synthesis of two proteins with Mr of 17,600 and less than 5000 are stimulated by a 3-h light pulse at CT 18.6 h which corresponds to the light-induced phase advance region. These results suggest that 80S ribosomal protein synthesis is involved in normal or light-entrainment functions of the circadian oscillator in pigeon pineal cells.

Animals↗