Relationship between interfacial superstructures and Schottky-barrier heights of Sb/GaAs contacts.
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Journal Article↗
Biomedical subjects
K Akimoto
Publications and source records attributed to K Akimoto.
Balloon occlusion aortography.
We review the validity of balloon occlusion aortography (BOA) on the basis of our personal experience with 18 patients with congenital heart disease (mean weight 4.55 g, including 8 neonates). Four of the 18 patients underwent aortic arch angiography using balloon occlusion of the descending aorta. Pulmonary angiography was also performed in 9 patients via a patent ductus arteriosus and in 3 patients via a Blalock-Taussig shunt. The remaining 2 patients underwent coronary arteriography by balloon occlusion of the ascending aorta. The information obtained was satisfactory in 17 of the 18 patients. However, in one patient with a double-outlet right ventricle and pulmonary stenosis, the pulmonary arteries were not clearly visualized because of dominant antegrade flow from the right ventricle. BOA is a safe and useful procedure which can be used to image the aortic arch, pulmonary artery, and coronary arteries in infants with congenital heart diseases. In children over 3 years of age, however, the balloon may not be able to occlude the appropriate site of the aorta, so selective angiography is required to obtain precise information.
Aorta, Thoracic↗
Percutaneous transluminal coronary angioplasty for Kawasaki disease: a case report and literature review.
A 31-month-old boy developed right coronary artery stenosis after Kawasaki disease for which he underwent percutaneous transluminal coronary angioplasty (PTCA). The narrowing of the right coronary artery was successfully dilated by angioplasty without apparent complication. This case suggests that PTCA may have a potential advantage as a temporary method to postpone the aortocoronary bypass surgery in a child with coronary artery stenosis due to Kawasaki disease. However, strict patient selection is recommended for coronary angioplasty.
Angioplasty, Balloon, Coronary↗
Sesamin is a potent and specific inhibitor of delta 5 desaturase in polyunsaturated fatty acid biosynthesis.
Incubation with sesame oil increases the mycelial dihomo-gamma-linolenic acid content of an arachidonic acid-producing fungus, Mortierella alpina, but decreases its arachidonic acid content [Shimizu, S., K. Akimoto, H. Kawashima, Y. Shinmen and H. Yamada (1989) J. Am. Oil Chem. Soc. 66, 237-241]. The factor causing these effects was isolated and identified to be (+)-sesamin. The results obtained in experiments with both a cell-free extract of the fungus and with rat liver microsomes demonstrated that (+)-sesamin specifically inhibits delta 5 desaturase at low concentrations, but does not inhibit delta 6, delta 9 and delta 12 desaturases. Kinetic analysis showed that (+)-sesamin is a noncompetitive inhibitor (Ki for rat liver delta 5 desaturase, 155 microM). (+)-Sesamolin, (+)-sesaminol and (+)-episesamin also inhibited only delta 5 desaturases of the fungus and liver. These results demonstrate that (+)-sesamin and related lignan compounds present in sesame seeds or its oil are specific inhibitors of delta 5 desaturase in polyunsaturated fatty acid biosynthesis in both microorganisms and animals.
Animals↗
The value of RI scintigraphy and angiography in small intestinal bleeding--report of eight cases.
We retrospectively reviewed eight cases of small intestinal bleeding and assessed the value of RI scintigraphy and angiography in diagnosing the bleeding site. The patients' average age was 56.2 years. Chief complaints was melena of variable degree. In most cases neither upper endoscopy nor colonoscopy was diagnostic. RI scintigraphy (Tc-99 labeled HSA) showed 75% of positive rate whereas angiography showed 66.7% (4/6) of positive rate. All four cases of leiomyosarcoma and leiomyoma demonstrated hypervascular stain and/or extra-vasation in angiography whereas RI scintigraphy failed to detect active GI bleeding in 2 of the 4 cases. Therefore angiography was considered useful for the detection of bleeding from leiomyoma and leiomyosarcoma which are often hypervascular. Scintigraphy is thought of most value in the demonstration of small amount of bleeding with minimum vascular abnormality.
Adult↗
Histological changes of the gallbladder and liver after extracorporeal shock wave lithotripsy for gallbladder.
The histological changes of the gallbladder and liver following extracorporeal shock wave lithotripsy (ESWL) were investigated in a canine model. After performing ESWL on human cholesterol stones placed in the gallbladder of 8 dogs, the gallbladder and livers were removed for pathological study. The mucosa of the gallbladder showed erosion and ulceration in three of the eight dogs. Edema and bleeding were found in the stroma of the gallbladder beds. Hemorrhagic necrosis and vacuolar degeneration occurred in liver parenchyma adjacent to the gallbladder bed, but the portal area was fairly well preserved. It can be said that ESWL caused damage to both the liver and the gallbladder, but its effects on the liver may be only slight because of the preservation of the portal area.
Animals↗
Structural and functional diversities of a family of signal transducing protein kinases, protein kinase C family; two distinct classes of PKC, conventional cPKC and novel nPKC.
Recent molecular cloning and biochemical experiments on the nature of protein kinase C (PKC) have revealed the existence of two distinct classes of phorbol ester (and diacylglycerol) receptor/protein kinase, conventional PKC (cPKC) and novel PKC (nPKC). Each of these classes contains multiple related molecules expressed in tissues and cells in a type-specific manner. Although nPKC does not show the typical PKC activity ascribable to conventional PKCs and thus was neglected in earlier studies, several lines of evidence suggest that nPKCs are involved in a variety of cell responses to physiological stimuli and phorbol esters. It is possible that in some cases nPKC is the major mediator of the so-called PKC-activators, such as phorbol esters, mezerein, and bryostatins. In addition to the clear difference between cPKC and nPKC, functional diversity among conventional PKCs has also been demonstrated; PKC gamma differs in its competence to mediate the signal toward transcriptional activation through TPA-responsive cis-acting elements from cPKC alpha and nPKC epsilon. The differences between cPKC and nPKC and among the individual members of each of these two classes, and their specific pattern of distribution in tissues and cells, provide a rationale by which to explain the specificity and diversity of cellular responses to external stimuli generating DAG and to phorbol esters. The results presented here also provide a means to dissect the complex signaling pathway in cells and to analyze the molecular basis underlying the signal transduction processes mediated by this family of protein kinases.
Animals↗
Extracellular ATP stimulates interleukin-dependent cultured mast cells and eosinophils through calcium mobilization.
We examined the effect of ATP and related nucleotides on the changes in intracellular calcium ([Ca2+]i) in murine bone marrow-derived mast cells (BMMC) and human cord blood-derived eosinophils (EO) cultured in the presence of interleukins. ATP, ADP and AMP released a substantial amount of histamine and leukotriene C4 from BMMC, and EO showed locomotive activity in response to ATP, ADP and GTP. These reactions were accompanied with an increase in [Ca2+]i in BMMC and in EO. The rise in [Ca2+]i in BMMC induced by ATP or antigen at optimal concentrations was inclined to be persisting. On the other hand, these nucleotides induced a rapid and transient rise in [Ca2+]i in EO. Purified human peripheral EO also exhibited locomotive activity and an increase in [Ca2+]i in response to ATP. These results indicate that extracellular ATP activates interleukin-dependent cultured mast cells and EO through Ca2+ mobilization, and suggest that ATP, which is known to be released from activated platelets or autonomic nerves, may stimulate in vivo counterparts of these cultured inflammatory cells.
Adenosine Triphosphate↗
Multinucleation of macrophages with dextran sulfate in vitro.
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Animals↗
Substance p-induced cutaneous and bronchial reactions in children with bronchial asthma.
We studied substance P-induced cutaneous and bronchial reactions in children with allergic disorders. Furthermore, inhibitory effects of lidocaine on these responses elicited by substance P were also studied. In the intradermal test, children with moderate or severe bronchial asthma showed significantly stronger reactions than controls. In bronchial challenge with substance P, children with bronchial asthma showed an increasing fall in FEV1 and V50 in proportion to the severity of their asthma. Concomitant use of lidocaine significantly inhibited not only substance P-induced intradermal erythema and wheal reactions but air flow limitations. It also inhibited histamine-induced erythema and house dust-induced wheal and erythema reactions. No adverse reactions to lidocaine were observed. These results suggest that substance P might play an important role in cutaneous and bronchial hypersensitivity reactions in humans and that lidocaine has an inhibitory effect on substance P-induced reactions.
Adolescent↗
Inhibition of cholesterol absorption and synthesis in rats by sesamin.
The effects of sesamin, a lignan from sesame oil, on various aspects of cholesterol metabolism were examined in rats maintained on various dietary regimens. When given at a dietary level of 0.5% for 4 weeks, sesamin reduced the concentration of serum and liver cholesterol significantly irrespective of the presence or absence of cholesterol in the diet, except for one experiment in which the purified diet free of cholesterol was given. On feeding sesamin, there was a decrease in lymphatic absorption of cholesterol accompanying an increase in fecal excretion of neutral, but not acidic, steroids, particularly when the cholesterol-enriched diet was given. Sesamin inhibited micellar solubility of cholesterol, but not bile acids, whereas it neither bound taurocholate nor affected the absorption of fatty acids. Only a marginal proportion (ca. 0.15%) of sesamin administered intragastrically was recovered in the lymph. There was a significant reduction in the activity of liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase after feeding sesamin, although the activity of hepatic cholesterol 7 alpha-hydroxylase, drug metabolizing enzymes, and alcohol dehydrogenase remained uninfluenced. Although the weight and phospholipid concentration of the liver increased unequivocally on feeding sesamin, the histological examination by microscopy showed no abnormality, and the activity of serum GOT and GPT remained unchanged. Since sesamin lowered both serum and liver cholesterol levels by inhibiting absorption and synthesis of cholesterol simultaneously, it deserves further study as a possible hypocholesterolemic agent of natural origin.
Absorption↗
Generation of strong MHD Alfvénic turbulence.
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Journal Article↗
Enhanced extracellular dopamine level may be the fundamental neuropharmacological basis of cross-behavioral sensitization between methamphetamine and cocaine--an in vivo dialysis study in freely moving rats.
Intracerebral dialysis was used to study the mechanism underlying cross-behavioral sensitization between methamphetamine (MAP) and cocaine. The challenge injection of cocaine caused a significantly greater increase in striatal perfusate dopamine (DA) levels in MAP-pretreated rats than in saline-pretreated rats. Similarly, the challenge injection of MAP caused a significantly greater increase in extracellular DA levels in cocaine-pretreated rats than in control rats. These results suggest that an enhancement in striatal DA efflux may play an important role in cross-behavioral sensitization between MAP and cocaine.
Animals↗
Coronary artery calcification in Kawasaki disease.
To evaluate the angiographic features of coronary lesions in Kawasaki disease with coronary artery calcification, cinefluoroscopy and cineangiography were retrospectively reviewed in 116 patients who had undergone coronary angiography between 1982 and 1989. Angiographic abnormalities of coronary arteries were demonstrated in 55 of the 116 patients. In 5 (9.1%) of the 55 patients, 9 with calcification were identified by cinefluoroscopy and chest x-ray. Eight of the 9 calcified lesions showed a circular or ring-shape configuration. Coronary angiography revealed a total occlusion of the right coronary artery with collateral circulation from the distal left coronary artery in 2 patients and a severe stenosis of the right coronary artery in 2 patients, in whom anticoagulant therapy had not been continued during the follow-up periods. The remaining patient in whom anticoagulant therapy had been continued had bilateral aneurysms but no significant stenosis. These results indicate that a ring-shape calcification on chest x-ray in a patient with a history of Kawasaki disease may suggest an involvement by coronary artery stenosis even when anticoagulant drugs had been given. Therefore, coronary angiography should be performed to evaluate the stenotic lesions if this type of calcification is found by routine radiographic examination.
Adolescent↗
Congenital coronary artery fistula: diagnosis by two-dimensional Doppler echocardiography.
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Child↗
Luminol chemiluminescence reaction catalyzed by a microbial peroxidase.
A peroxidase produced by microorganisms belonging to the genera Arthromyces and Coprinus was found to be a potent catalyst for the chemiluminescent oxidation of luminol, the luminescence produced per unit of microbial peroxidase protein being well over 100 times as strong as that produced by horseradish peroxidase. No large difference in Km value for H2O2 in the presence of luminol was found between Arthromyces ramosus peroxidase and horseradish peroxidase (7.0 and 15.5 microM, respectively), but Vmax of the Arthromyces peroxidase was 500 times greater than that of the horseradish peroxidase. It was also found that the Arthromyces peroxidase surpasses, beyond expectation, the horseradish peroxidase in the initial velocity of the chemiluminescence reaction with the stopped-flow method. The Arthromyces peroxidase was used for the glucose and cholesterol assays, which were notably more sensitive than the corresponding assays involving the horseradish peroxidase.
Calibration↗
Treatment of status asthmaticus--hormone changes before and after aminophylline i.v. drip therapy.
The treatment of status asthmaticus is one of the most important factors in controlling the patient with asthma attacks. We have studied hormone changes in status asthmaticus and considered what is the best treatment in the asthma attack condition in children. Antidiuretic hormone (ADH), renin activity, and aldosterone activity are elevated in severe asthma attack conditions, and these high levels are correlated with high levels in Wood's clinical score. It is theoretical that patients with dehydration and respiratory failure show such elevation in hormones, and it is well known that under such conditions beta 2-stimulant enhances renin production. From our study, it is concluded that beta 2-stimulant subcutaneous injection must be considered in status asthmaticus. In children, aminophylline i.v. drip therapy may be one of the best treatments in status asthmaticus.
Adolescent↗
Multinucleation of macrophages with water-solubilized lignin derivatives in vitro.
When macrophages derived from bone marrow were incubated with lignin derivative at 10 micrograms/ml, they formed multinucleated giant cells containing more than sixty nuclei. Cine-microscopic observation revealed that the formation of the giant cells was due to cell fusion. This phenomenon was specific for primary-cultured macrophages, and was not observed with either a macrophage cell line or established cell lines derived from other tissues.
Animals↗