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Biomedical subjects

K Fujii

Publications and source records attributed to K Fujii.

At least 667 records · Page 37Linked to original sources
PubMed1989

Limited atrial compensation to reduced early diastolic filling in hypertensive patients with advanced left ventricular hypertrophy: a Doppler echocardiographic study.

To assess atrial contribution to left ventricular (LV) filling in hypertension, we studied, using pulsed Doppler echocardiography, 22 hypertensive patients without apparent LV hypertrophy (LVH), 12 hypertensive patients with LVH, and 24 age-matched normal subjects. From mitral flow velocity waveform, we determined peak velocity of early diastolic filling flow (peak E), peak velocity of late diastolic filling flow (peak A), and the peak A/peak E ratio (peak A/peak E). Peak E decreased in hypertensives without apparent LVH and showed a further decrease in hypertensives with LVH compared with normal subjects (57 +/- 8 [mean +/- SD]; P less than 0.001, 46 +/- 7; P less than 0.0001, vs 65 +/- 10 cm/s). On the other hand, peak A/peak E increased in hypertensives without apparent LVH, and greatly increased in hypertensives with LVH (1.06 +/- 0.14; P less than 0.001, 1.40 +/- 0.29; P less than 0.0001, vs 0.79 +/- 0.21). However, increased peak A was not significantly different between the hypertensive groups (60 +/- 8 vs 64 +/- 8; NS, both; P less than 0.001 vs 50 +/- 10 cm/s for normal subjects). In hypertensives, we found no significant correlation between peak A and the wall thickness index (WTI, determined as mean LV wall thickness normalized by LV diastolic dimension), whereas peak E was significantly correlated with WTI (r = -0.65; P less than 0.001). Our findings indicate that atrial contraction can not fully compensate the decrease in early diastolic filling caused by advanced LVH. We conclude that atrial compensation for reduced early diastolic filling is limited in hypertensive patients with advanced left ventricular hypertrophy.

Adult↗
PubMed1989

Effects of nonsteroidal antiinflammatory drugs on collagen biosynthesis of cultured chondrocytes.

In conclusion, the data obtained from the present study show that TA has less effect than indomethacin or ASA on cultured chondrocytes in gene expression and synthesis of collagen. These findings cannot be directly interpolated to clinical application, but attention to pharmacologic activities of NSAIDs on chondrocytes may have future applications. Two major NSAIDs, TA, indomethacin, and ASA, were examined for their effects on the biosynthesis and gene expression of articular cartilage collagen. The biosynthesis of type II collagen was suppressed to 70% to 80% of the control by indomethacin and ASA. TA did not suppress collagen synthesis. To know the gene expression of type II collagen, dot blot hybridization was performed using type II collagen cDNA. The effects of NSAIDs on the amount of type II collagen mRNA were consistent with those on collagen biosynthesis. Thus, TA had the least effect on cultured chondrocytes.

Animals↗
PubMed1989

Microsurgical procedures for management of giant middle cerebral aneurysm causing increased intracranial pressure.

There have not been many cases reported of giant aneurysms of the middle cerebral artery with a remarkable mass and causing increased intracranial pressure, and the successful operation for resecting an aneurysm is still low. Considering it essential that the mass of an aneurysm should be reduced and the blood flow of parent and distal arteries should be preserved, we are reporting two successful results.

Adult↗
PubMed1989

Determination of caffeine in saliva by high-performance liquid chromatography: new sampling method for saliva using filter paper.

We report an assay method for the determination of salivary caffeine concentrations by high-performance liquid chromatography. A simple, new method for collecting mixed saliva using a piece of filter paper has been developed. An arbitrary amount of saliva is absorbed and a fixed amount of internal standard is added. The mean coefficient of variation of measurements repeated by changing both volumes absorbed and caffeine concentrations of saliva was 5.6% with this method. The detection limit was determined to be 0.5 microgram/ml. Precision of measurements and recoveries did not depend upon the volume of saliva absorbed. Four volunteers were given a capsule of 230 mg caffeine, and saliva was collected by the ordinary method using chemical stimulation with citric acid and by our filter paper absorption methods; the methods were compared. Salivary caffeine concentrations were always lower than plasma concentrations, and there were no big differences between two methods, although salivary concentrations measured by our method was higher, with a significant difference at 1.5 h after dosing. From the practical viewpoint this method would be convenient and sufficiently accurate.

Adult↗
PubMed1989

The effects of cromakalim on the detrusor muscle of human and pig urinary bladder.

The effects of cromakalim, a potassium channel activating drug, have been studied on isolated detrusor muscle strips from normal Landrace boar, normal and unstable mini-pig and unstable human bladder. Cromakalim abolished spontaneous activity in all strips but did not abolish the ability of the detrusor muscle from any of the specimens studied to respond to carbachol, increased extracellular K+ or transmural nerve stimulation. Intravenous infusion of cromakalim in the urethral obstructed mini-pig caused the characteristic unstable contractions associated with bladder outflow obstruction to be abolished, leaving the animal able to void. Experiments with potassium isotopes and the sucrose gap technique demonstrated that cromakalim increased the potassium permeability and hyperpolarised the cell membrane, consistent with its reported actions on other smooth muscles. These results suggest that drugs such as cromakalim, which act by reducing membrane excitability without inhibiting responses to existing innervation, may have a clinical application in the treatment of instability which is secondary to bladder outflow obstruction.

Animals↗
PubMed1989

The effect of cromakalim on the smooth muscle of the guinea-pig urinary bladder.

1. The actions of cromakalim were studied on the detrusor muscle from guinea-pig urinary bladder. Cromakalim reduced the frequency and amplitude of spontaneous contractile activity of the smooth muscle of the guinea-pig urinary bladder at 5 x 10(-8)M and abolished the activity at concentrations above 5 x 10(-7)M. 2. Electrophysiological experiments demonstrated that cromakalim increased membrane conductance, caused a dose-dependent hyperpolarization of the cell membrane and loss of spike activity. These events are consistent with the opening of K+ channels. 3. The effects of 10(-6)M and 10(-5)M cromakalim on the contractile responses to carbachol, potassium and transmural nerve stimulation were studied. Cromakalim did not prevent the detrusor from responding to these agents, although it significantly reduced the contractile response to K+ at concentrations below 70 mM. 4. Uptake and efflux experiments using 86Rb+ were unable to demonstrate any significant effect on transmembrane movement produced by cromakalim (10(-5)M). 5. 43K+ efflux showed a dose-dependent increase in the rate constant on addition of cromakalim. The difference in the selectivity for K+ over Rb+ was confirmed in dual label uptake experiments. 6. Substitution experiments in which the K+ ions in the tissue were gradually replaced by Rb+ demonstrated that cromakalim had a progressively decreasing effect on spontaneous activity as internal K+ was lowered. When all the K+ was replaced by Rb+, cromakalim no longer inhibited spontaneous activity, confirming that the channel opened by cromakalim appears relatively impermeant to Rb+.

Animals↗
PubMed1989

Cerebrospinal fluid lactate in patients with diabetes mellitus and hypoglycaemic coma.

Cerebrospinal fluid (CSF) lactate and pyruvate concentrations were determined in 20 patients with diabetes mellitus but without disturbance of consciousness and five who recovered from hypoglycaemic coma. CSF lactate was slightly but significantly higher in diabetes mellitus (1.78, SEM 0.04 m mol/l) than that in 15 control subjects (1.40, SEM 0.05 m mol/l). In those who recovered from hypoglycaemic coma, CSF lactate was markedly elevated to 2.45-4.43 m mol/l. CSF glucose concentrations, however, were substantially the same between treated hypoglycaemic and diabetes mellitus groups. These findings indicate that CSF lactate levels increase with glycaemic levels in diabetes mellitus owing to enhanced glucose influx into glycolytic pathway of the brain, and also increases in treated hypoglycaemic coma probably due to mitochondrial dysfunction or damage.

Brain Damage, Chronic↗
PubMed1989

Regional cerebral blood flow and metabolism in patients with transient global amnesia: a positron emission tomography study.

In four patients who experienced transient global amnesia (TGA), clinical features and neuroradiological findings including positron emission tomography (PET) were studied within three months of the episodes, and compared with those in seven cases with cerebral transient ischaemic attacks (TIA). None of TGA patients had a previous history or significant risk factors for the cerebrovascular diseases. Their electroencephalogram, brain CT and angiogram for the head and neck were almost normal. PET study showed better preserved cerebral blood flow and oxygen metabolism in each area of the brain in patients with TGA compared with those with TIA in whom focal reductions of flow and metabolism were evident. These observations suggest that TGA is caused by reversible circulatory and/or metabolic disturbance, of which mechanism might be different from that in TIA.

Amnesia↗
PubMed1989

Moderately proteinuric IgA nephropathy: prognostic prediction of individual clinical courses and steroid therapy in progressive cases.

Eighteen of 60 patients with persistent moderate proteinuria between 1.0 and 2.0 g/day and a long-term follow-up of more than 4 years received steroid therapy for a mean period of 18 months. Fifteen of these 18 patients maintained their initial creatinine clearance (CCr) of 70 ml/min or more. The remaining 42 received antithrombocyte drugs and/or nonsteroidal anti-inflammatory drugs, with 31 of them keeping their initial Ccr values of 70 ml/min or more. All 14 cases with initial Ccr values of less than 70 ml/min in both the steroid and nonsteroid groups followed progressive courses, with 12 ending up in hemodialysis. Of the nonsteroid, preserved group of 31 cases, 12 followed a stable course, 10 a progressive course, and the other 9 went into end-stage renal failure necessitating hemodialysis. There were no differences in initial clinical features among these three subgroups. But histological changes were milder in the stable subgroup than in the progressive and hemodialysis subgroups. Further, the total score of eight histological parameters was 6 or less in all but 1 of the cases of the stable subgroup, but 8 or higher in the other two subgroups. Therefore, in the progressive cases alone with initial Ccr values of 70 ml/min or more and high total scores of 7 or more, the long-term clinical courses were compared between steroid and nonsteroid groups (10 and 20 cases, respectively). In the steroid group proteinuria decreased significantly and renal function was preserved well as compared with that in the nonsteroid group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1989

Cerebral ischemia in spontaneously hypertensive rats with type 2 (noninsulin-dependent) diabetes mellitus, cerebral blood flow and tissue metabolism.

The present study was designed to examine the effect of chronic type 2 (noninsulin-dependent) diabetes mellitus on cerebral blood flow and metabolism during cerebral ischemia induced by bilateral carotid artery occlusion in spontaneously hypertensive rats. Diabetes was produced by streptozotocin treatment in 2-day neonates and the experiment was performed at the age of 5 months. The level of mean arterial pressure was not different between diabetic and nondiabetic rats. At 1 h after ischemia, cerebral blood flow was decreased to 1% of the resting value and supratentorial lactate was increased by 8-fold of control, being virtually the same in both groups of rats. In contrast, reduction of cerebral ATP was much less in diabetic rats (1.64 +/- 0.15 mmol/kg) than in nondiabetic rats (0.74 +/- 0.07 mmol/kg) (p less than 0.001); ATP in nonischemic control is 2.80-2.85 mmol/kg. These results could not be explained by the difference in cerebral blood flow between the groups during ischemia. The results suggest that chronic mild hyperglycemia exerts rather a protective effect on the brain against ischemic insult. Effective utilization of metabolites, such as glucose and ketone bodies, may play an important role to minimize metabolic derangements in the ischemic brain in type 2 diabetic-hyperglycemic rats.

Adenosine Triphosphate↗
PubMed1989

Effect of alpha 2-adrenergic receptor antagonist (midaglizole) on gastrointestinal motility in conscious dogs.

To clarify the physiological role of the mechanism that adrenergic nerve inhibits Ach release from intramural cholinergic nerve endings, the influence of Midaglizole, alpha 2-adrenergic receptor antagonist, to postprandial gastrointestinal motilities in conscious dogs was investigated. Postprandial motilities of gastric antrum, duodenum, ileum, and colon were significantly enhanced by Midaglizole (3.0-5.0 mg/kg body weight, i.v.). These excitatory responses were abolished by atropine (0.05-0.1 mg/kg body weight, i.v.). On the other hand, in most cases (29 cases out of 32), when Midaglizole was administered during quiesent phase of IMC, no change occurred in gastrointestinal motility. However, after subliminal dose of pentagastrin or cisapride, which stimulated Ach release from intramural cholinergic neuron without development of motility, was administered, Midaglizole induced phasic, postprandial motility-like contraction in gastrointestinal tract. Even in the fasted state, when Midaglizole was administered intragastrically, irregular contractions with high amplitude occurred in every regions from gastric antrum to colon. And these excitatory responses were abolished by atropine. Similar reaction was observed also in truncal vagotomized dogs. These results suggest that it is the physiological mechanism that adrenergic nerve presynaptically inhibits Ach release from intramural cholinergic neuron, which is the main mechanism of development of postprandial motility, acting on alpha 2-adrenergic receptor, and has tonic control of postprandial motility.

Adrenergic alpha-Antagonists↗
PubMed1989

Fatigue properties of acrylic denture base resins.

Observations were made of fractured surfaces caused by flexural and tensile fatigue tests made in polymethyl methacrylate denture base resins (PMMA). In addition, the changes in dynamic viscoelastic and tensile properties of the materials along with fatigue propagation were investigated. In the tensile and flexural fatigue tests, both the fractured surfaces, which had striations on their surfaces and cracks near the fractured section, closely resembled each other in appearance. On the other hand, all of the tensile properties, such as elastic modulus, toughness and tensile strength, decreased with the increase of the number of stress cycles in the fatigue test. The storage modulus (E') of the material decreased gradually along with fatigue propagation over the whole range of temperatures tested. The loss modulus (E") and mechanical loss tangent (tan delta) increased slightly. The fatigue limit of four commercial denture base resins varied widely from one product to another.

Dental Stress Analysis↗
PubMed1989

Mathematical model of the frog skeletal muscle--analysis of non-linear mechanical properties.

A mathematical model of the skeletal muscle, consisting of contractile and series elastic components of the contracting muscle as well as viscoelastic components of the resting muscle is presented, in which the contractile component obeying the force-load-velocity relation is expressed by two components, a force generator and a viscous-like component. Since it is one of the most significant properties of the muscle that the mechanical properties depend upon the contractile force (the intensity of the active state), detailed attention is given to the explanation of those non-linear properties. Parameters of the model are determined based on physiological observations obtained from fiber bundles prepared from the frog semitendinosus muscle. While viscoelasticity is constant at the resting state, the series elastic coefficient of the contracting muscle increases with an increase in tension and the viscous-like coefficient also increases linearly with increasing contractile force. This model is checked by digital simulation against responses to ramp stretch of the muscle of the steady and transient contractions. A close agreement is shown between the simulated results and the experimental ones. The model can explicitly account for the non-linear mechanical properties of the contracting muscle.

Animals↗
PubMed1989

The effects of vasoactive drugs on halothane inhibition of contractions of rat mesenteric lymphatics.

The effects of halothane on alpha-adrenergic receptors, beta-adrenergic receptors, and the process of Ca++ dependent contractions on rat mesenteric lymphatics were examined. Halothane depressed the contraction rate of mesenteric lymphatics but did not effect the increase in lymphatic contraction rate caused by noradrenaline (an alpha-agonist). The depressant effect of halothane on the contraction rate was also not antagonized by propranolol (a beta-blocker), but was partly reversed by CaCl2. These findings suggest that the depressant effect of halothane on the lymphatic contraction rate derives not from blocking lymphatic alpha-receptors or stimulating lymphatic beta-receptors but rather by halothane inhibition on the process of Ca++ dependent lymphatic contractions.

Animals↗
PubMed1989

Pentane as an index of in vitro lipid peroxidation via microsomal NADPH-P-450 enzyme systems.

Pentane was measured in a mixture of guinea pig liver microsomes and carbontetrachloride (CCl4) in the presence of nicotineamide adenine dinucleotide phosphate (NADPH) and under anaerobic conditions by gas chromatography. Pentane of 0.2 pmol/mg protein/min was formed in the presence of NADPH without CCl4. Pentane formation increased to 2.0 pmol/mg protein/min in the presence of CCl4 and NADPH. This reaction required an anaerobic atmosphere, 2.1 mmol/litter of NADPH and 13.4 mmol/litter of CCl4 under optimal conditions. The formation was reduced in the presence of oxygen, glutathione, vitamin E and metyrapone. These results clearly show that pentane is formed by lipid peroxidation initiated by the free radical cleavage products of CCl4, which are anaerobically produced by NADPH-dependent microsomal enzymes. We conclude that pentane is a good index of in vitro lipid peroxidation via microsomal NADPH-P-450 enzyme systems.

Animals↗
PubMed1989

[A case of renal leiomyoma with remarkable calcification].

A case of renal leiomyoma with remarkable calcification is reported. The patient is a 46-year-old female. The tumor is 9 x 10 x 12 cm in size and is occupied by granular minute calcifications. Angiographically segmental arteries are stretched by a tumor, in which there are minute tumor vessels and inhomogeneous tumor stain.

Calcinosis↗
PubMed1989

[Clinical studies of 15 cases of progressive systemic sclerosis (PSS) associated with positive proteinuria and membranous glomerulonephritis].

In this study, we demonstrated that the patients with PSS who develop proteinuria during the course are much more prone to develop lung fibrosis, telangiectasia, serositis and esophageal hypomotility. They also exhibited positive LE cell phenomenon, lupus band test, thrombocytopenia and leukopenia. The mortality rate is significantly higher in proteinuria positive patients and abnormal clinical data described above seem to be the risk factors for the development of renal involvement in PSS.

Adult↗