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Biomedical subjects

K Fujii

Publications and source records attributed to K Fujii.

At least 793 records · Page 44Linked to original sources
PubMed1986

Effects of Ca2+ on ethanolaminephosphotransferase and cholinephosphotransferase in rabbit platelets.

The effects of Ca2+ on ethanolaminephosphotransferase [EC 2.7.8.1] and cholinephosphotransferase [EC 2.7.8.2] activities in rabbit platelet membranes were studied using endogenous diglyceride and CDP-[3H]ethanolamine or CDP-[14C]choline as substrates. Both transferases required Mn2+, Co2+, or Mg2+ as a metal cofactor and the optimal concentrations of the metals for both activities were about 5, 10, and 5 mM, respectively. When 5 mM Mg2+ was used as a cofactor, both transferase activities were inhibited by a low concentration of Ca2+ (half maximal inhibition at approx. 15 microM). In the presence of 5 mM Mn2+, however, approx. 5 mM Ca2+ was required to produce half maximal inhibition. The Ca2+-induced inhibition was reversible and the rate of the inhibition was not affected either by the concentrations of the CDP-compound or by exogenously added diacylglycerol. The relationship between Ca2+ and both Mg2+ and Mn2+ on the transferase activities was competitive. 45Ca2+ binding (and/or uptake) to the platelet membranes was inhibited by Mn2+, Mg2+, and Co2+, in a concentration-dependent manner. However, the inhibitory effects of the three metal ions on the total Ca2+ binding (and/or uptake) did not correlate with the activation of both transferase activities by the three metal ions in the presence of Ca2+. These results suggest that both transferase activities are regulated by low concentrations of Ca2+ in the presence of optimal concentrations of Mg2+, and that the inhibition is mediated directly by Ca2+, which interacts with a specific metal cofactor binding site(s) of the transferases.

Animals↗
PubMed1986

Thyrotropin releasing hormone levels in human cerebrospinal fluid in various neurologic diseases.

Thyrotropin releasing hormone (TRH) in the human cerebrospinal fluid (CSF) of 102 patients with non-neurologic and neurologic diseases was measured by a specific TRH radioimmunoassay. TRH levels in CSF were 17.6 +/- 3.4 pg/ml (mean +/- SE) in non-neurologic diseases. TRH levels in CSF were significantly elevated in cases of spinal cord tumor and multiple sclerosis (acute phase). Elevated TRH levels in CSF were decreased in these diseases by operation or prednisolone treatment, respectively. From these data, it is suggested that TRH is present in the human CSF and that measurement of TRH levels in CSF may be a useful indicator of the activity of certain neurologic diseases.

Adolescent↗
PubMed1986

Mechanism of vasodilation induced by alpha-human atrial natriuretic polypeptide in rabbit and guinea-pig renal arteries.

Effects of alpha-human atrial natriuretic polypeptide (alpha-HANP) on electrical and mechanical properties of smooth muscle cells of the guinea-pig and rabbit renal arteries and of the guinea-pig mesenteric artery were investigated. alpha-HANP (up to 10 nM) modified neither the membrane potential nor resistance of smooth muscle cells of the guinea-pig and rabbit renal arteries. In the guinea-pig mesenteric and renal arteries, alpha-HANP (up to 10 nM) had no effect on the amplitude and facilitation (mesenteric artery) or depression (renal artery) of excitatory junction potentials nor on action potentials. In the guinea-pig renal artery, alpha-HANP (up to 10 nM) had no effect on the depolarization induced by noradrenaline (NA) (up to 10 microM) but markedly inhibited NA-induced contraction. alpha-HANP (10 nM) slightly inhibited the K-induced contraction. In the rabbit renal artery, alpha-HANP (10 nM) inhibited the NA-induced contraction and to a lesser extent the K-induced contraction. In the rabbit renal artery, the effects of alpha-HANP on the release of Ca from the cellular storage by two applications of NA, and its re-storage, were investigated in Ca-free solution containing 2 mM-EGTA. When 5 nM-alpha-HANP was applied before and during the first application of 0.5 microM-NA, the contraction was markedly inhibited but the contraction to a second application of 10 microM-NA was potentiated. If the first dose of NA was 10 microM the effect was very small. Under the same experimental procedures, nitroglycerine (10 microM) showed almost the same effects as alpha-HANP on the NA-induced contractions. When both the first (3 mM) and second (10 mM) contractions were evoked by caffeine in Ca-free solution, alpha-HANP (5 nM) and nitroglycerine (10 microM) inhibited both contractions to the same extent. In the rabbit renal artery, applications of alpha-HANP or nitroglycerine increased the amount of guanosine 3',5'-phosphate (cyclic GMP) in a dose-dependent manner. However, a much higher concentration of nitroglycerine was required (2 X 10(3) times). In the rabbit renal artery, hydrolysis of phosphatidyl inositol 4,5-bisphosphate (PI-P2) activated by 0.5 microM-NA was inhibited by alpha-HANP, in a dose-dependent manner, but activation by 10 microM-NA was not inhibited by alpha-HANP (up to 100 nM).(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1986

Pathogenesis of impending myocardial infarction and acute myocardial infarction: clinical and angiographic evaluation of coronary thrombosis as a precipitating factor.

In order to investigate the role of coronary thrombosis as a precipitating factor of acute myocardial infarction (AMI), we examined coronary angiographic findings in 89 patients with AMI taken within 24 hours of the onset and in 42 patients with prolonged angina attack of impending myocardial infarction (impending MI) taken within 50 hours of the last angina attack. Furthermore, in the patients with impending MI, the effects of intracoronary and intravenous thrombolytic therapy and anticoagulant therapy used to prevent impending MI from developing into AMI, were also studied. (1) In 72 of 89 patients (81%) with AMI, coronary thrombi were detected angiographically. The thrombi were detected most frequently (88%) in angiographs taken within 3 hours of onset. (2) In 23 of 42 patients with impending MI, coronary thrombi were detected angiographically. In 6 patients with coronary thrombi who underwent intracoronary thrombolysis during angina attack, occlusive coronary thrombi in ischemia-related vessels were the observed, and recanalization by thrombolysis with intracoronary urokinase infusion relieved chest pain and improved ECG changes. (3) The incidence of AMI in 42 patients with impending MI who were treated with intracoronary and intravenous thrombolytic therapy and anticoagulant therapy was significantly less than in the conventional therapy group (80 patients) (11.9% vs. 27.5%; p less than 0.05). In 4 of 5 patients with developing AMI, coronary thrombi were detected angiographically in the acute phase of impending MI. These results indicate that coronary thrombosis plays an important role not only in the precipitation of impending MI but also in the development of impending MI to AMI.

Angina Pectoris↗
PubMed1986

The effects of intravenous infusion of solutions with different colloid osmotic pressures on rat mesenteric lymph pressure.

The effects of intravenous infusion of solutions of varied colloid osmotic pressure on mesenteric lymph pressure were measured by a glass micropipette. The lymph pressure was 4.0 +/- 1.6 cm H2O between the second and third valve of rat mesenteric lymphatic vessels with diameter of 101 +/- 25 micron (mean +/- SD). Intravenous infusion of 1 ml/100g body weight (B.W.) of isotonic saline, 5% glucose solution, and 20% glucose solution increased the lymph pressure by 1.6 +/- 0.5 cm H2O, 1.5 +/- 0.3 cm H2O and 2.0 +/- 1.0 cm H2O, respectively. Infusion of 2 ml/100g B.W. of the same solutions increased the lymph pressure by 3.3 +/- 1.3 cm H2O, 3.3 +/- 1.6 cm H2O and 3.7 +/- 0.8 cm H2O, respectively. Infusion of hydroxyethyl starch solution, with colloid osmotic pressure of 25 mmHg, minimally altered the lymph pressure. One ml/100g B.W. infusion of low molecular weight dextran solution, with colloid osmotic pressure of 162 mmHg, decreased the lymph pressure by 1.3 +/- 0.9 cm H2O, and 2 ml/100g B.W. infusion of this solution decreased the lymph pressure by 2.0 +/- 1.0 cm H2O. The different effects on lymph pressure derive from the differences in colloid osmotic pressure of these solutions in conformity with the Starling hypothesis.

Animals↗
PubMed1986

[An autopsy case of malignant lymphoma of the pancreas].

Case reports of malignant lymphoma of the pancreas are extremely rare. We experienced a 36-year-old man with malignant lymphoma involving the pancreas associated with obstructive jaundice, confirmed by autopsy. It is very difficult to differentiate between pancreatic carcinoma and pancreatic malignant lymphoma. Age, icterus, diffuse pancreatic enlargement, pathological findings and tumor markers may be useful in suggesting lymphoma. Trials of positive biopsy, appropriate radiotherapy and chemotherapy are necessary in patients who may have malignant lymphoma of the pancreas.

Adult↗
PubMed1986

Steroid therapy in IgA nephropathy: a prospective pilot study in moderate proteinuric cases.

Forty-three patients with IgA nephropathy whose proteinuria persisted between 1.0 and 2.0 g/day were assessed in an uncontrolled pilot study of steroid treatment. Fourteen patients receive an initial dose of 40 mg/day of prednisolone, followed by gradual reduction of the dose over an average period of about 19 months. After discontinuation of corticosteroids, they were treated with non-steroid anti-inflammatory drugs and/or anti-thrombocyte drugs to the end of the study. Another 29 patients received non-steroid anti-inflammatory drugs and/or anti-thrombocyte drugs throughout the study. Fourteen patients treated with steroids experienced considerable reduction in proteinuria and maintained renal function over 81 months. In 29 patients treated with non-steroid anti-inflammatory drugs and/or anti-thrombocyte drugs alone, proteinuria did not decrease and renal function deteriorated significantly during 60 months. At the end of the study, differences in degree of proteinuria and in levels of renal function between the steroid and non-steroid groups were statistically significant. In addition, these differences became more distinct in patients with initial creatinine clearance values 70 ml/min or more in both groups. These results suggest that treatment with steroids in IgA nephropathy may be beneficial, especially in the early stage of the disease.

Adult↗
PubMed1986

Reconstruction of scutum defects (scutumplasty) for attic cholesteatoma.

The use of a small plate of autogenous bone to reconstruct a scutum defect--scutumplasty--in combined approach tympanoplasty in 79 patients with attic cholesteatoma has been studied for a period of one or more years. The bone plate obtained from the mastoid cortex and sculptured to the proper size and shape was snugly fitted between two grooves made by a bur at the anterior and posterior bony external canal wall just proximal to the scutum defect. In this series, recurrence of postoperative cholesteatoma in the attic was found in 5.1%, and retraction pockets, which remained dry and self-cleaning, were seen in 3.8% of the patients. Postoperative hearing results were satisfactory in 68.3%, and hearing was unchanged or deteriorated in 31.7%.

Cholesteatoma↗
PubMed1985

Responsiveness of Clare-Bishop neurons to visual cues associated with motion of a visual stimulus in three-dimensional space.

Photic responsiveness of cells in the medial bank of the lateral suprasylvian cortex (Clare-Bishop area) was studied using a three-dimensional visual stimulator that reproduced two visual cues (motion disparity and change in size) for perception of three-dimensional motion of a visual stimulus. About one third of them (48/148) were selectively responsive to motion disparity corresponding to approaching (AP cells, n = 30) or recessive motion (RC cells, N = 18), another half to motion of retinal images in the same direction between the two eyes corresponding to fronto-parallel motion (FP cells, n = 75), and the remaining cells were rather equally responsive to these types of stimuli (NS cells, n = 25). More than a half of the AP (19/30) or RC (11/18) cells were also responsive to increase or decrease in stimulus size, respectively, and they were optimally activated by a combination of the motion and size stimuli while relatively few FP and NS cells were sensitive to change in stimulus size. These findings indicate that the Clare-Bishop cells encode three-dimensional motion on the basis of photic responsiveness to the motion and size cues.

Animals↗
PubMed1985

Electrophysiological and morphological correlates in the development of visual cortical circuitry in infant kittens.

Geniculate axons in cat visual cortex establish excitatory connections with cortical cells in supragranular and granular layers at birth. They are localized to the granular layer for the first month after birth. Retraction of geniculocortical synapses parallels axonal extension of spiny stellate cells to the supragranular layer and establishment of synapses for intracortical transmission.

Animals↗
PubMed1985

Effects of calcium antagonists on smooth muscle membranes of the canine stomach.

In circular muscles of the canine stomach, diltiazem (greater than 3 X 10(-6)M) depolarized and nicardipine (greater than 10(-6)M) hyperpolarized the membrane. Diltiazem (greater than 5 X 10(-6)M) or nicardipine (greater than 3 X 10(-7M) inhibited the plateau potential of spontaneously generated or electrically evoked action potential. In Na-deficient solution (between 137 and 30 mM Na), diltiazem and nicardipine selectively inhibited the plateau potential. In Na- (15 mM Na) or Ca-deficient (0.25 mM Ca) solution, spontaneously generated action potential ceased, and only graded responses were evoked by electrical stimulation. These graded responses were inhibited by diltiazem (greater than 5 X 10(-6)M) or nicardipine (greater than 3 X 10(-7)M). The ionic contribution for generation of action potential in this muscle cell was discussed in relation to actions of Ca antagonists.

Action Potentials↗