Search PubMed⌕ Search

Biomedical subjects

N Shoji

Publications and source records attributed to N Shoji.

At least 55 records · Page 3Linked to original sources
PubMed1994

Potent inhibitors of histamine release: polyhydroxylated sterols from the Okinawan soft coral Sinularia abrupta.

A new polyhydroxylated steroid (24-methylene-1 alpha, 3 beta, 11 alpha-trihydroxycholest-5-ene-18-oic acid-3-acetate, 1) and known related compounds (2-4) from the soft coral Sinularia abrupta have potently inhibited histamine release from rat peritoneal mast cells induced by anti-immunoglobulin E. The inhibitory effect of 1 was approximately 6500 times stronger than that of disodium cromoglycate, a well-known antiallergic drug.

Animals↗
PubMed1994

Triterpenoid glycosides from Anagallis arvensis.

From the herb of Anagallis arvensis, we have isolated four novel oleanane glycosides, anagallosaponins VI-IX, and two artifact saponins, apoanagallosaponins III and IV, formed from anagallosaponins III and IV. The structures were elucidated by chemical and spectral methods, 2D NMR techniques being particularly helpful. The structures of anagallosaponins VI and VII were characterized as priverogenin B 3-O-beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside and 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)]beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside), respectively. The structures of anagallosaponins VIII and IX were characterized as 23-hydroxypriverogenin B 22-acetate 3-O-(beta-D-xylopyranosyl (1-->2)-O-beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)]beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]- alpha-L-arabinopyranoside), respectively. The structures of apoanagallosaponins III and IV were characterized as camelliagenin A 16-acetate 3-O-beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-alpha-L-arabnopyranoside, 3-O-(beta-D-xylopyranosyl (1-->2)-O-beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), respectively.

Carbohydrate Conformation↗
PubMed1994

Baccharane glycosides from seeds of Impatiens balsamina.

From the seeds of Impatiens balsamina have been isolated four rare baccharane glycosides, hosenkosides L-O. The structures of all isolates were secured by the use of 2D NMR techniques (1H-1H COSY, HMQC, HMBC, ROESY) and chemical derivatization. Hosenkosides L and M are hosenkol A 3-O-sambubiosyl-28-O-glucoside and 3-O-sambubiosyl-26-O-glucosyl-28-O-glucoside, respectively. Hosenkoside N is hosenkol C 3-O-glucosyl-28-O-glucoside. Hosenkoside O is hosenkol D 3-O-sophorosyl-28-O-glucoside.

Glycosides↗
PubMed1994

Axon reflex vasodilatation in cat dental pulp elicited by noxious stimulation of the gingiva.

Antidromic stimulation of sensory nerves has been shown to increase blood flow in the tissue they innervate. This study was designed to determine if antidromic vasomotor responses occur in feline dental pulp and if they are mediated by branched axons supplying both tooth pulp and gingiva. Dynamic changes in pulpal blood flow (PBF) elicited by electrical stimulation, pinching, heating, and capsaicin application to the gingivae were investigated in cat mandibular canine teeth by means of Laser Doppler Velocimetry. All inferior alveolar nerve bundles and the cervical sympathetic trunk had been previously sectioned to avoid the occurrence of brainstem reflexes, e.g., somato-autonomic vasomotor reflexes. Increases in PBF were observed in seven out of 12 cats when a restricted gingival area adjacent to the canine teeth was stimulated as described, but the increases were abolished after the sensitive gingival area was painted with lidocaine jelly, a surface anesthetic. These vasodilator responses, remarkably reduced following repeated application of 30 mM of capsaicin, are considered to be induced via antidromic activation of capsaicin-sensitive nociceptive nerve fibers, presumably by axon reflex mechanisms, suggesting that nerve terminals supplying the gingiva originate from parent axons which have collaterals that innervate the canine tooth pulp.

Animals↗
PubMed1994

Hosenkosides F, G, H, I, J, and K, novel baccharane glycosides from the seeds of Impatiens balsamina.

From the seeds of Impatiens balsamina we have isolated six novel baccharane glycosides, hosenkosides F-K. The structures of all isolates were determined by the use of two dimensional (2D) NMR techniques (1H-1H correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple-bond correlation (HMBC), rotating frame Overhauser enhancement spectroscopy (ROESY), total correlation spectroscopy (TOCSY)) and chemical derivatization. Hosenkosides F, H and I are hosenkol B 3-O-sambubiosido-26-O-glucoside, 3-O-sambubioside and 3,26-O-diglucoside, respectively. Hosenkoside G is hosenkol C 3-O-sambubiosido-28-O-glucoside. Hosenkosides J and K are hosenkol A 3-O-sophoroside and 3-O-sophorosido-26-O-glucosyl-28-O-glucoside, respectively.

Carbohydrate Sequence↗
PubMed1994

Structures of anagallosaponins I-V and their companion substances from Anagallis arvensis L.

From the herb of Anagallis arvensis L., we have isolated five novel oleanane glycosides, anagallosaponins I-V and the artifact, methyl anagallosaponin I, besides anagallosides A, B, C, and desglucoanagallosides A and B. The structures of isolates were identified by the use of 2D-NMR techniques (1H-1H correlation spectroscopy (COSY), 1H-detected heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple quantum coherence (HMBC), rotating frame Overhauser enhancement spectroscopy (ROESY), total correlation spectroscopy (TOCSY). The structures of anagallosaponins I and II were characterized as anagallogenin A. 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)-] beta-D-glucopyranosyl (1-->4)- [beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside) and anagallogein A 22-acetate 3-O-(beta-D-xylopyranosyl (1-->2)-O-beta-D- glucopyranosyl (1-->4)-[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), respectively. The structures of anagallosaponins III, IV and V were characterized as priverogenin B 22-acetate 3-O-beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside, 3-O-(beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)]-beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside), respectively. Methyl anagallosaponin I, the methylacetal of anagallosaponin I might be derived from anagallosaponin I during the isolation procedure.

Carbohydrate Conformation↗
PubMed1993

Mechanism of inhibition of IgE-dependent histamine release from rat mast cells by xestobergsterol A from the Okinawan marine sponge Xestospongia bergquistia.

Histamine release from rat peritoneal mast cells induced by anti-IgE was essentially complete within 4-5 min. Xestobergsterol A and B, which are constituents of the Okinawan marine sponge Xestospongia bergquistia Fromont, dose-dependently inhibited anti-IgE-induced histamine release from rat mast cells. The IC50 values of xestobergsterol A and B for histamine release in mast cells activated by anti-IgE were 0.07 and 0.11 microM, respectively. Anti-IgE stimulated PI-PLC activity in a mast cell membrane preparation. Xestobergsterol A dose-dependently inhibited the generation of IP3 and membrane-bound PI-PLC activity. Moreover, xestobergsterol A inhibited Ca(2+)-mobilization from intracellular Ca(2+)-stores as well as histamine release in mast cells activated by anti-IgE. On the other hand, xestobergsterol B did not inhibit the membrane-bound and cytosolic PI-PLC activity, IP3 generation or the initial rise in [Ca2+]i in mast cells activated by anti-IgE. These results suggest that the mechanism of inhibition by xestobergsterol A of the initial rise in [Ca2+]i, of the generation of IP3, and of histamine release induced by anti-IgE, was through the inhibition of PI-PLC activity.

Animals↗
PubMed1993

Histamine release from rat mast cells induced by the inhibition of adenosinetriphosphatase for Na and K channels.

6-Tridecylresorcylic acid (TRA) caused histamine release from rat peritoneal mast cells in a dose-dependent manner. The release of histamine by TRA was also time dependent. On the other hand, high K+ (150 mM) strongly inhibited TRA-induced histamine release from rat mast cells. These results suggest that histamine release from mast cells might be associated with K+ channel activity.

Actomyosin↗
PubMed1993

Effects of topical application of UF-021, a novel prostaglandin-related compound, on aqueous humor dynamics in rabbit.

The mechanism underlying the intraocular pressure (IOP) lowering effect of a novel prostaglandin-related compound, (+)-isopropyl Z-7-[(1R,2R,3R,5S)-3,5-dihydroxy-2-(3-oxodecyl)-cyclopentyl]hept-5 -enoate (UF-021), and the influence of this new hypotensive agent on the permeability of the blood-aqueous barrier (BAB) were studied in albino rabbits. A single instillation of 0.06% UF-021 significantly lowered the IOP with a peak reduction of 5.2 mmHg without changing the aqueous flow rate. Uveoscleral outflow and outflow facility to general blood circulation were both increased. The BAB permeability evaluated with fluorescein isothiocyanate-labeled rabbit albumin (FITC-RA) showed approximately sixfold increase after a single instillation of 0.06% UF-021, which suggested a drug-induced compromise of the rabbit BAB.

Administration, Topical↗
PubMed1993

[A five-year follow-up of the effect of postoperative 5-fluorouracil subconjunctival injections on the surgical outcome of trabeculectomy].

The effects of postoperative subconjunctival 5-fluorouracil (5-FU) injections on the surgical outcomes of trabeculectomy were studied after a 5-year follow-up in 263 eyes of glaucoma patients by the life table analysis. The success probability (%) to maintain the postoperative intraocular pressure (IOP) less than 21 mmHg without medication was 58.2 for primary open angle glaucoma (POAG), 54.8 for secondary glaucoma (SG) and 27.8 for refractory glaucoma, that with or without medication was 92.5 for POAG, 87.4 for SG and 57.5 for refractory glaucoma. The success probability (%) to maintain the postoperative IOP less than 16 mmHg without medication was 55.2 for POAG, 49.8 for SG and 24.5 for refractory glaucoma, that with or without medication was 77.9 for POAG, 66.8 for SG and 26.9 for refractory glaucoma. In each type of glaucoma, the difference between the 5-FU treated and the control groups was highly significant (p < 0.01 or less, log-rank test). Corneal epithelial defect was noted in 38.8%, but no late complications, for example, perforation or necrosis of sclera, were observed. These results indicate that we can use postoperative subconjunctival 5-FU without risk of serious complications.

Adult↗
PubMed1992

Potent inhibitors of histamine release, two novel triterpenoids from the Okinawan marine sponge Penares incrustans.

Two novel triterpenoids with an unusual 14-carboxyl group, penasterone [1] and acetylpenasterol [2], were isolated from the Okinawan marine sponge Penares incrustans. The structures of 1 and 2 were established mainly on the basis of nmr spectroscopic data. The relative stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis. Compounds 1 and 2 potently inhibited histamine release from rat peritoneal mast cells induced by anti-IgE in a dose-dependent manner.

Animals↗
PubMed1992

Postoperative subconjunctival 5-fluorouracil injections and success probability of trabeculectomy in Japanese: results of 5-year follow-up.

The effects of postoperative subconjunctival 5-fluorouracil (5-FU) injections on the surgical outcome of trabeculectomy in the Japanese were studied in a total of 362 eyes of 263 glaucoma patients with the postoperative follow-up of 1-9 years. The probability of successful intraocular pressure (IOP) control at the 5-year point of the continuing follow-up was calculated by the life-table method of Kaplan-Meier. The eyes that had undergone trabeculectomy with postoperative injections of 5-FU (5-FU group) included 165 eyes with primary open-angle glaucoma (POAG), 38 eyes with secondary glaucoma (SG) and 60 eyes with refractory glaucoma. The eyes that had undergone trabeculectomy without postoperative 5-FU (control group) included 46 eyes with POAG, 31 eyes with SG and 22 eyes with refractory glaucoma. The surgical techniques and postoperative care were virtually identical between the two groups, except that the control group did not receive the postoperative 5-FU. The total amount of 5-FU given to each case averaged 36.5, 36.0 and 49.5 mg for POAG, SG and refractory glaucoma, respectively. At the 5-year follow-up point, the probability of maintaining IOP control below 21 mmHg with or without medication in the 5-FU group was 92.5% for POAG, 87.4% for SG and 57.5% for refractory glaucoma; while without medication the probability was 58.2, 54.8 and 27.8%, respectively. The probability of IOP control below 16 mmHg with or without medication in the 5-FU group was 77.9% for POAG, 66.8% for SG and 26.9% for refractory glaucoma; without medication the probability was 55.2, 49.8 and 24.5%, respectively. In the control group, the corresponding probability for each type of glaucoma was much lower than that in the 5-FU group, and the probability for IOP control below 16 mmHG was 0.12% at the 5-year follow-up point. In the 5-FU group, the mean postoperative IOP in successfully treated eyes remained at about 12 mmHg throughout the first 5 years of the follow-up period. There was no significant difference in incidence of postoperative complications between the 5-FU and control groups, except that corneal epithelial defect was noted in 38.8% of the eyes in the 5-FU group. No late complications related to the use of postoperative 5-FU were observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Calcium metabolism in acidotic patients induced by carbonic anhydrase inhibitors: responses to citrate.

Calcium metabolism and its response to citrate were examined in 51 patients with glaucoma receiving carbonic anhydrase inhibitors (acetazolamide or methazolamide). Metabolic acidosis, hypocitraturia and increased incidence of nephrolithiasis were induced by both drugs. However, the acidosis was milder with methazolamide administration. Normocalciuria was observed in 29 patients and was shown to be a result of low filtered calcium. Renal hypercalciuria in 16 patients was associated with elevated parathyroid hormone but nephrogenic cyclic adenosine monophosphate remained within normal limits. Citrate in the form of potassium citrate (4.3 mmol.) and sodium citrate (4.0 mmol.) did not correct the metabolic acidosis or hypocitraturia but consistently decreased fasting and 24-hour urinary calcium excretion in patients with renal hypercalciuria. This event did not occur in patients with normocalciuria or absorptive hypercalciuria. These results suggest that a small amount of citrate could reverse renal hypercalciuria without correcting the metabolic acidosis.

Acetazolamide↗
PubMed1990

[Isolation and identification of yibeinoside A].

Two steroidal alkaloids were isolated from the bulb of Fritillaria pallidiflora Schreb by column chromatographic techniques. One of them was identified as known alkaloid sinpeinine A, another alkaloid was found to be a new compound named yibeinoside A, which is the Sinpeinine-3-O-beta-glucoside. Its structure was confirmed on the basis of chemical and spectral data (IR, MS, 1HNMR, 13CNMR).

Cevanes↗
PubMed1988

Cardiotonic action of [8]-gingerol, an activator of the Ca++-pumping adenosine triphosphatase of sarcoplasmic reticulum, in guinea pig atrial muscle.

[8]-Gingerol (gingerol), a component of ginger, produced a concentration-dependent positive inotropic effect on guinea pig isolated left atria at concentrations of 1 X 10(-6) to 3 X 10(-5) M. Gingerol also exhibited positive inotropic and chronotropic effects on guinea pig right atria. The gingerol-induced inotropic effect was abolished by ryanodine, but was little affected by propranolol, chlorpheniramine, cimetidine, tetrodotoxin, diltiazem or reserpine. The time to peak tension and relaxation time within a single contraction were shortened by gingerol (1 X 10(-5) M) as well as isoproterenol, whereas they were prolonged by BAY K 8644. In guinea pig isolated atrial cells, gingerol (3 X 10(-6) M) caused an increase in the degree and the rate of longitudinal contractions. In guinea pig left atria, gingerol (1 X 10(-6) to 3 X 10(-5) M) gave little influence on the action potential, although it increased the contractile force of the atria. The whole-cell patch-clamp experiments showed that the slow inward current was little affected by gingerol (1 X 10(-6) to 3 X 10(-5) M) in voltage-clamped guinea pig cardiac myocytes. The measurement of extravesicular Ca++ concentration using a Ca++ electrode indicated that gingerol (3 X 10(-6) to 3 X 10(-5) M) accelerated the Ca++ uptake of fragmented sarcoplasmic reticulum (SR) prepared from canine cardiac muscle in a concentration-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1987

Gingerol, a novel cardiotonic agent, activates the Ca2+-pumping ATPase in skeletal and cardiac sarcoplasmic reticulum.

Gingerol, isolated as a potent cardiotonic agent from the rhizome of ginger, stimulated the Ca2+-pumping activity of fragmented sarcoplasmic reticulum (SR) prepared from rabbit skeletal and dog cardiac muscles. The extravesicular Ca2+ concentrations of the heavy fraction of the fragmented SR (HSR) were measured directly with a Ca2+ electrode to examine the effect of gingerol on the SR. Gingerol (3-30 microM) accelerated the Ca2+-pumping rate of skeletal and cardiac SR in a concentration-dependent manner. The rate of 45Ca2+ uptake of HSR was also increased markedly by 30 microM gingerol without affecting the 45Ca2+ efflux from HSR. Furthermore, gingerol activated Ca2+-ATPase activities of skeletal and cardiac SR (EC50, 4 microM). The activation of SR Ca2+-ATPase activity by gingerol (30 microM) was completely reversed by 100-fold dilution with the fresh saline solution. Kinetic analysis of activating effects of gingerol suggests that the activation of SR Ca2+-ATPase is uncompetitive and competitive with respect to Mg . ATP at concentrations of 0.2-0.5 mM and above 1 mM, respectively. Kinetic analysis also suggests that the activation by gingerol is mixed-type with respect to free Ca2+ and this enzyme is activated probably due to the acceleration of enzyme-substrate complex breakdown. Gingerol had no significant effect on sarcolemmal Ca2+-ATPase, myosin Ca2+-ATPase, actin-activated myosin ATPase and cAMP-phosphodiesterase activities, indicating that the effect of gingerol is rather specific to SR Ca2+-ATPase activity. Gingerol may provide a valuable chemical tool for studies aimed at clarifying the regulatory mechanisms of SR Ca2+-pumping systems and the causal relationship between the Ca2+-pumping activity of SR and muscle contractility.

Adenosine Triphosphate↗