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Biomedical subjects

H Fujimura

Publications and source records attributed to H Fujimura.

At least 73 records · Page 4Linked to original sources

The vasorelaxant effect of evocarpine in isolated aortic strips: mode of action.

The effect of evocarpine (EVO), a quinolone alkaloid isolated from Evodiae fructus, on Ca2+-blocking activity has been examined. In the isolated rat thoracic aorta evocarpine significantly inhibited the contraction induced by 60 mM K+ with an IC50 of 9.8 microM, and that induced by external Ca2+ in the depolarized muscle in concentrations of 10-100 microM. The relaxant effect of evocarpine and verapamil was antagonized by Bay K8644. The increase of 45Ca2+-influx induced by 60 mM K+ was significantly inhibited by 100 microM evocarpine. In the isolated rabbit thoracic aorta 100 microM evocarpine had no effect on the norepinephrine-induced contraction in normal medium or on the phasic contraction in Ca2+-free medium or on the transient relaxation induced by activation of the Na+ pump. The content of cyclic AMP or cyclic GMP was unchanged. These results suggest that evocarpine inhibits Ca2+ influx through voltage-dependent calcium channels.

Alkaloids

The peripheral neuropathy of necrotizing arteritis: a clinicopathological study.

We have reviewed the clinical and morphological data from 100 patients with necrotizing arteritis in muscle and/or in nerve samples taken by biopsy. The neuropathy occurred in the context of a multisystem disorder (Group 1) or in apparent isolation (Group 2). The average age of patients was 59 in Group 1 and 61 in Group 2. Females were more commonly affected than males, especially in the first group. Necrotizing arteritis complicated the course of rheumatoid arthritis in 25 patients. In 3 patients necrotizing arteritis was associated with infection with the human immunodeficiency virus, the agent of AIDS. Tests for hepatitis B surface antigen were positive in 19 patients. Mononeuritis was present in 13, mononeuritis multiplex in 62, and distal symmetrical sensory or sensorimotor neuropathy in 19 patients. In both groups of patients, the muscle biopsy was more frequently diagnostic for arteritis than was the nerve biopsy (80% versus 55%). The average incidence of isolated fibers undergoing axonal degeneration was 64.8%; that of demyelinated/remyelinated fibers was 1.9%. We conclude that the combination of nerve and muscle sampling increases the chance of visualizing characteristic arterial lesions in vasculitic neuropathy.

Adult

Effect of alismol on adrenergic mechanism in isolated rabbit ear artery.

Effects of alismol, a sesquiterpenoid isolated from the rhyzome of Alisma orientale, on adrenergic mechanisms were examined in the isolated rabbit ear artery. Alismol (10(-6) to 10(-4) M) inhibited the contraction of isolated rabbit ear artery by electrical stimulation of the perivascular nerves. The inhibition was concentration-dependent; at a concentration of 10(-4) M, the inhibition was 90% (n = 8). Treatment with 10(-4) M alismol inhibited the increase in 3H-noradrenaline (3H-NAd) release induced by electrical stimulation by 63 +/- 6%. Alismol at 10(-4) M did not affect the neuronal uptake of 3H-NAd in the artery. Alismol at 10(-4) M slightly inhibited contractions induced by exogenously administered NAd. These results demonstrate that alismol inhibits the adrenergic neuro-effector mechanisms in rabbit ear artery, and they suggest that alismol acts primarily on nerve terminals and inhibits their responses to electrical stimulation by interfering with NAd release.

Animals

Effectiveness of continuous arteriovenous hemofiltration for patients with refractory heart failure.

Continuous arteriovenous hemofiltration (CAVH) was carried out in 8 patients with refractory congestive heart failure. All these patients had heart failure and oliguria for over 24 hours and intensive treatment with digitalis, diuretics, catecholamines and vasodilators was prescribed. Hemodynamics were followed closely during CAVH. During CAVH, pulmonary arterial pressure and pulmonary capillary wedge pressure were significantly reduced in all patients, the right atrial pressure decreased in 6 with right cardiac failure, the heart rate decreased in 3 with tachycardia and the blood pressure and cardiac index were elevated in 3 with hypotension. These observations show that CAVH can be performed safely and effectively in patients with congestive heart failure, oliguria and hypotension.

Adult

Effects of alismol isolated from Alismatis Rhizoma on calcium-induced contraction in the rabbit thoracic aorta.

We examined the inhibitory effects of alismol, a sesquiterpenoid isolated from Alismatis Rhizoma, on vascular contractions induced by high concentrations of K+ and Ca2+, and on 45Ca2+ retention in normal and in high K+-containing medium. Alismol affected neither the resting tension nor the 45Ca2+ retention in normal medium, but it inhibited sustained contraction and increased 45Ca2+ retention induced by high K+ concentrations. Alismol did not affect norepinephrine-induced contractions in normal medium, nor phasic contractions in Ca2+-free medium. These results suggested that alismol inhibited mainly Ca2+ influx through a voltage-dependent Ca2+ channel.

Animals

Terminal segment of Kluyveromyces lactis linear DNA plasmid pGKL2 supports autonomous replication of hybrid plasmids in Saccharomyces cerevisiae.

By use of linear DNA plasmid pGKL2 from the yeast Kluyveromyces lactis we have constructed hybrid plasmids carrying a LEU2 gene of Saccharomyces cerevisiae as a selectable marker. The replication properties of hybrid plasmids in yeasts were investigated. We demonstrated that the insertion of a LEU2 gene into pGKL2 resulted in circularization of the hybrid plasmids and pGKL2 segment supported autonomous replication of the plasmids. Moreover, the hybrid plasmids propagated autonomously, independently of the presence of the natural pGKL2 plasmid.

Base Sequence

Palliative laser therapy.

Endoscopic laser treatment has been tried for hemostasis, relief of stenosis and reduction of tumor volume in advanced upper gastrointestinal cancer. This form of treatment was found to be effective for each purpose, but success was usually only temporary. Thus, it was considered that endoscopic laser therapy for problems of advanced upper GI cancer could perhaps be improved by modifying the technique and/or developing new methods, such as the combination of the laser with other therapies.

Aged

[Screening test for calcium antagonist in natural products. The active principles of Uncariae ramulus et uncus].

We have previously reported on the Ca2+-blocking activity and active constituents of natural products. In the course of screening, Uncariae ramulus et uncus, a chinese herbal medicine, was found to possess such activity. In this paper, we attempted to characterize its active constituent which plays an important role in Ca2+-blocking activity. Its active principles were identified to be oxyindole-type alkaloids, rhynchophylline, corynoxeine, isorhynchophylline and isocorynoxeine, that showed inhibitory effects, similar to that of verapamil, on contractile response to high concentration of potassium ion (rats), CaCl2 (rats), norepinephrine in normal and Ca2+-free medium (rats and rabbits) and 45Ca2+-uptake (rats) in thoracic aorta with an activity two orders of magnitude less than the activity of verapamil.

Alkaloids

[Role of the involvement of the reticular formation in the dementia of Parkinson's disease].

A post mortem study of 14 cases of Parkinson's disease was reported. Seven patients were mentally deteriorated and 7 were not, retrospectively. The semiquantitative study of the cortical lesions of senile dementia of Alzheimer type did not show any recognizable difference between the 2 groups. A greater degree of neuronal cell loss in the nucleus basalis of Meynert in the mentally deteriorated group was confirmed. The incidence of Lewy bodies in the brain stem reticular formation was remarkably increased in the mentally deteriorated group. A study of the reticular formation, including the raphe nuclei and the magnocellular nuclei of mid pons and upper medulla, revealed a significant higher incidence of Lewy bodies throughout the whole reticular formation in the mentally deteriorated group. The possible role of the lesions of the ascending reticular activating system in the mental deterioration is discussed.

Dementia

Effects of crude drugs on experimental hypercholesterolemia. I. Tea and its active principles.

The effect of methanol extractives from tea leaves on hypercholesterolemia was examined in animal models. It was found that orally administered (-)-epicatechin gallate and (-)-epigallocatechin gallate from tea leaves lowered the serum cholesterol level in mice fed a high fat emulsion. Quantitation of tissue cholesterol and examination of liver tissues in mice fed a high cholesterol diet revealed that these constituents also significantly lowered the amount of cholesterol crystallization. These results support the reputed effectiveness of tea use in hypercholesterolemia.

Animals

Analgesic and anti-inflammatory activities in rats of alpha-(3,5-di-t-butyl-4-hydroxybenzylidene)-gamma-butyrolactone (KME-4), and its intestinal damage.

alpha-(3,5-Di-t-butyl-4-hydroxybenzylidene)-gamma-butyrolactone (KME-4), an anti-inflammatory drug, possesses analgesic activity in rat models. In the acetic acid-induced writhing test, the oral ED50 values for KME-4, indomethacin, naproxen and ibuprofen were 5.2, 3.8, 7.0 and 18.6 mg kg-1, respectively, and the relative order of potency of these drugs correlated with their inhibitory effect on acetic acid-induced vascular permeability in rats. KME-4 also had analgesic activity in the tests of Randall-Selitto and adjuvant arthritic flexion, but the dose required was greater than that needed in the writhing test. KME-4 (10 mg kg-1 day-1 orally) has a preventive effect against adjuvant-induced arthritis in rats, and its efficacy was more potent than indomethacin (2 mg kg-1 day-1) as judged from various parameters determined. When administered orally to rats once daily for 12 days, KME-4 caused perforating ulceration of the small intestine but this action was less potent than the effect of indomethacin, naproxen and ibuprofen.

4-Butyrolactone