Search PubMed⌕ Search

Biomedical subjects

M Higuchi

Publications and source records attributed to M Higuchi.

At least 397 records · Page 22Linked to original sources
PubMed1983

Catecholamine sensitivity and cardiac myosin ATPase activity in dogs treated with propranolol.

The effects of propranolol treatment on adrenoceptor reactivity and on cardiac myosin ATPase activity have been studied. Eight mongrel dogs weighing 8 to 14 Kg were given propranolol orally 3 times daily (10 mg/Kg/day) for 2 weeks. Although the levels of propranolol were effective and there was a significant decrease in resting heart rate, there was no evidence of a rebound adrenoceptor hypersensitivity after abrupt withdrawal of propranolol treatment. The responsiveness of cardiovascular systems to 1-isoproterenol (1-ISO) was significantly attenuated 15 hrs after the last medication, but it did not differ from the premedication levels 6 days after discontinuation of medication. The effects of 1-ISO on adenylate cyclase activity in the myocardial membrane preparations were not significantly different between the 3 groups (no medication, 1 day and 6 days after discontinuation). With propranolol treatment, though a rise in total plasma catecholamine (norepinephrine, epinephrine, dopamine) levels was the predominant change, there were no definite changes in respective catecholamines. Serum triiodothyronine (T3) increased during medication in 7 of the 8 animals and decreased after medication. Calcium-activated and K+-activated myosin ATPase activity in the inner and outer layers of the left ventricular wall were uniform in unmedicated dogs, and propranolol produced no significant effects. No reliable evidence for propranolol withdrawal syndromes was provided in the present study.

Adenosine Triphosphatases↗
PubMed1983

Changes in the nucleus pulposus of the intervertebral disc in bipedal mice. A light and electron microscopic study.

Bipedal mice were produced by clipping the forelimbs and tails of mice within one week of birth. Using light and electron microscopy, the nucleus pulposus of the lumbar intervertebral disc in the bipedal mice was compared with that in normal mice at three, six, and 12 months of age. In normal neonatal mice, the nucleus pulposus is composed of densely packed notochordal cells, which undergo degenerative changes and decrease in number with age. In the bipedal mice, degenerative changes in the nucleus pulposus were accelerated, and herniation of the nucleus pulposus occurred frequently. At the same time, active chondrocytes associated with cartilage matrix appeared in the nucleus pulposus. This sequence of morphologic changes in the nucleus pulposus of the bipedal mice resembles the age-related changes that occur in the nucleus pulposus of the human intervertebral disc. These morphologic changes can be accelerated by creating abnormal mechanical stress. Chondrocytes in the nucleus pulposus may develop from surrounding cartilaginous tissue--cartilage plates and annulus fibrosus.

Aging↗
PubMed1983

[Report on 15 cases of multiple primary cancers in our department].

Of 512 gynecological malignant cases treated in our department, 22 were suspected of multiple primary cancer; 15 were confirmed by clinical and pathological findings, representing an incidence of 2.9% (15/512) of all malignant cases. The most frequent sites of other cancers in patients with cervical cancer were intestinal (5/15), mammary (3/15) and urinary (2/15). Nine (60%) of 15 multiple primary cancers were noted within 12 months. Two rare combinations are also reported. There was a patient with Grawitz's tumor (kidney) and epidermoid cancer (uterine cervix) and one with leiomyosarcoma (uterine corpus) and epidermoid cancer (uterine cervix).

Aged↗
PubMed1982

Interactions of diuretics with the renal kallikrein-kinin and prostaglandin systems.

The renal kallikrein-kinin system may participate in the diuretic, natriuretic and antihypertensive effect of diuretics. This possibility was investigated by studying the influence of hydrochlorothiazide on blood pressure and urinary kallikrein excretion in patients with essential hypertension. Furthermore, the effect of kallikrein-blockade and prostaglandin-synthesis inhibition on the acute furosemide-induced changes of diuresis, natriuresis, GFR and renal plasma flow were studied in normotensive subjects. Thiazide treatment normalized the reduced kallikrein excretion of the hypertensive patients. The fall in mean arterial blood pressure was significantly correlated with the increase in urinary kallikrein excretion. In the normotensive subjects aprotinin-induced kallikrein inhibition failed to alter the acute response to furosemide, whereas indomethacin attenuated the diuretic and natriuretic effect of furosemide. The combination of indomethacin and aprotinin had a greater suppressive effect on plasma renin activity than indomethacin alone, suggesting a participation of kallikrein in renin release. An increase in the activity of the renal kallikrein-kinin system may contribute to the long-term antihypertensive effect of thiazide diuretics but it does not seem to be involved in the acute renal responses to furosemide.

Adult↗
PubMed1982

Ocular manifestations of Kawasaki's disease (mucocutaneous lymph node syndrome).

In a prospective study of the ocular manifestations of Kawasaki's disease (mucocutaneous lymph node syndrome) in 18 children (11 boys and seven girls, ranging in age from 5 months to 9 years), we found bilateral injection of the bulbar conjunctiva in 16, bilateral iridocyclitis in 14, superficial punctate keratitis in four, vitreous opacities in two, papilledema in two, and subconjunctival hemorrhage in one. Conjunctival injection and iridocyclitis were always bilateral, and fellow eyes always had the same degree of inflammation. There were significant correlations between ocular inflammation and erythrocyte sedimentation rate (P less than .0001) and C-reactive protein level (P less than .0009). No serious ocular complications occurred.

Blood Sedimentation↗
PubMed1982

Percutaneous embolisation of major spinal cord artery as a treatment for intractable spasticity.

Based on the angiographic findings of the injured spinal cord percutaneous embolisation of Adamkiewicz's artery was carried out to control intractable spasticity in ten cases of late stage spinal cord paralysis. The purpose of this procedure was to interrupt the reflex arcs of the lower extremities by decreasing the blood supply to the lumbar enlargement. Results were excellent in two cases, good in five and poor in three. Major effects were found in adduction and flexion spasticity of the hip joints and bladder function was always preserved in these patients. It is speculated that occlusion of Adamkiewicz's artery mainly affected the lower thoracic and the upper lumbar segments. Anastomosis between the anterior spinal artery and the two posterior spinal arteries might have provided sufficient collateral blood circulation to the conus level. It is emphasised that the percutaneous embolisation of Adamkiewicz's artery reduced the intractable spasticity of the lower extremities without changes in the voiding function of the automatic bladder.

Adult↗
PubMed1982

Identification of PK 1 bacteriophage DNA in Streptococcus mutans.

A lysogenic bacteriophage PK 1 and plasmid DNA's in Streptococcus mutans PK 1 have been characterized by electron microscopy PK 1 phage DNA molecules were observed in both linear and circular forms, which gave the molecular weights of (28.9 +/- 0.4) x 10(6) and (27.4 +/- 0.2) X 10(6) daltons, respectively. Plasmid DNA has a molecular weight of 4.0 X 10(6) daltons. No difference of density in CsCl density gradient between linear and circular forms of phage DNA and plasmid DNA was observed.

Bacteriophages↗
PubMed1982

Effects of 4-aminopyridine and tetraethylammonium on relaxant responses of isolated dog coronary arteries to 2-nicotinamidoethyl nitrate (SG-75).

Effects of 4-aminopyridine (4-AP) and tetraethylammonium (TEA) on vasodilator actions of 2-nicotinamidoethyl nitrate (SG-75) were investigated using isolated dog coronary arteries. SG-75 10(-8)--10(-4) Gm/ml produced concentration-dependent relaxations of coronary arterial strips which were contracted with potassium 30 mM or prostaglandin (PG) F2 alpha 10(-6) Gm/ml. Both 4-AP 5 x 10(-4) Gm/ml and TEA 1.6 x 10(-3) Gm/ml produced further contractions of the strips under potassium or PGF 2 alpha contracture. The potency to constrict the strips was greater in 4-AP than in TEA. 4-AP 5 x 10(-4) Gm/ml and TEA 1.6 x 10(-3) Gm/ml did not affect the SG-75-induced relaxations of the strips under potassium-contracture, but significantly depressed them under PGF2 alpha-contracture. In the strips under a resting state, 4-AP 5 x 10(-4) Gm/ml increased tension and produced oscillations in their contractions, but TEA 1.6 x 10(-3) Gm/ml did not. Results suggest that SG-75 may display its relaxant effect on isolated dog coronary arteries in part through an increase in potassium conductance.

4-Aminopyridine↗
PubMed1982

Gas chromatography-mass spectrometric determination of fatty acids in seed oil of winged bean (Psophocarpus tetragonolobus (L.) DC).

Fatty acids of winged bean seed oil were examined by gas chromatography-mass spectrometry of their pyrrolidide derivatives. Oleic and linoleic acids were determined to be the major unsaturated fatty acids in the oil. Long chain saturated fatty acids, such as behenic and lignoceric acids, were found in relatively high amounts as compared with other edible seed oils. The fatty acids that could not be separated by gas liquid chromatography were identified as linolenic acid and arachidic acid respectively on mass spectrometric analysis. Parinaric acid, previously reported by Cerny et al., was not detected and this supposed fraction was instead found to be eiconsenoic acid. Erucic acid, suspected of having an adverse effect on myocardial lesions in rats, was detected but only in small quantity. The identifications of these unsaturated fatty acids were further confirmed by deducing the location of the double bonds in their moieties. From these findings, winged bean seed oil can be suggested as being a food source of favorable quality.

Dietary Fats↗
PubMed1982

Relaxant effect of trapidil on isolated dog bronchus.

Relaxant effects of trapidil on dog bronchi were pharmacologically analyzed in vitro. Trapidil concentration-dependently relaxed bronchial strips contracted with methacholine, histamine or potassium. In the strips under methacholine-contracture, theophylline, papaverine, isoproterenol and atropine produced concentration-dependent relaxations. Propranolol significantly decreased isoproterenol-induced relaxations of bronchial strips under methacholine-contracture, but did not trapidil-induced relaxations. Prostaglandin (PG) E1 and PGE2 in high doses slightly relaxed bronchial strips under methacholine-contracture, but PGI2 hardly affected them. Tranylcypromine did not influence relaxant responses of the strips to trapidil. The results indicate that trapidil produces relaxations of bronchial smooth muscle through a non-specific action other than adrenergic beta-receptor activation or endogenous prostaglandin biosynthesis.

Animals↗
PubMed1982

Effects of nitroglycerin on transmural energy metabolism in the underperfused canine heart.

Effects of nitroglycerin on hemodynamics and transmural distribution of myocardial metabolites were studied at 40% of control coronary perfusion pressure induced by acute coronary stenosis in the canine heart. At 40% of coronary perfusion pressure, high energy phosphate (ATP, creatine phosphate) contents significantly diminished in all layers, especially in the inner layer. A 0.3 micrograms/kg/min intracoronary infusion of nitroglycerin showed no direct effects on energy metabolism in the underperfused myocardium. A 3 micrograms/kg/min i.v. administration of the drug under fixed coronary constriction resulted in decrease in left ventricular peak systolic pressure and systemic blood pressure, and further decrease in coronary perfusion pressure and coronary blood flow. Left ventricular end diastolic pressure and ST-segment of the epicardial ECG were elevated. High-energy phosphate contents further decreased while inorganic phosphate and lactate showed an increase. Under these conditions, release of the constriction sufficient for retention of the coronary perfusion pressure at about 40 mm Hg resulted in significant improvement of the myocardial energy metabolism without a further increase in coronary blood flow. The results suggest that when the myocardium is underperfused due to undilatable stenotic vessels with maximum autoregulation of the regional flow, it may be dangerous to administer nitroglycerin in a dose sufficient to produce a large decrease in coronary perfusion pressure.

Adenosine Triphosphate↗
PubMed1982

Human T cell hybridomas producing lymphokines. I. Establishment and characterization of human T cell hybridomas producing lymphotoxin and migration inhibitory factor.

Stable human T cell hybridomas were produced by cell fusion between PHA-activated human peripheral blood lymphocytes and human acute lymphatic leukemia cells of a CEM cell line whose proliferation had been inhibited by treatment with an irreversible protein synthesis inhibitor (emetine) and an irreversible RNA synthesis inhibitor (actinomycin D). Two hybrid cell lines (E10, F8) thus produced expressed OKT3-reactive antigen, HLA-A1 and -B8 antigens derived from CEM cells, and HLA-A2 antigen derived from PBL, and they have 10 more chromosomes than CEM cells. Furthermore, these cell lines continuously secreted lymphotoxin over 3 mo. E10 was found to produce MIF in addition to lymphotoxin. Cloning of E10 and the relationship between the functions and surface phenotypes of E10 sublines were examined. Lymphotoxin-producing hybrids (E10-15 and E10-37) express more OKT8-reactive antigen than OKT4-reactive antigen, while lymphotoxin and MIF-producing hybrids (E10-25, E10-42, and E10-43) express more OKT4-reactive antigen than OKT8-reactive antigen.

Antibodies, Monoclonal↗