Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0428
    Keywords: Insulin ; 3-hydroxy-3-methylglutaryl coenzyme A ; sterol synthesis ; human mononuclear leucocytes ; post-transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Incubation of freshly isolated human mononuclear leucocytes in lipid-depleted serum for 4 h resulted in a two-fold increase in 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity. Insulin, when added to the incubation medium at concentrations of 10 and 100 nmol/l at zero time, caused additional increases in the enzyme activity of 30% and 37%, respectively. The hormone action was not immediate because no effect was observed when insulin was added at 4 h and activity examined thereafter. Under these conditions sterol synthesis from 14C-acetate and tritiated water was strictly proportional to the activity of HMG-CoA reductase. Cycloheximide (20 μg/ml), a translational inhibitor of protein synthesis, prevented the insulin-mediated increase in the enzyme activity and the incorporation of 14C-acetate into sterols. Cordycepin (50 μg/ml) inhibited messenger RNA synthesis by 〉 50%, but had no inhibitory effect on the induction of HMG-CoA reductase and sterol synthesis. Low density lipoprotein (80 μg protein/ml) and complete serum blocked the induction of the enzyme and sterol synthesis from 14C-acetate caused by lipid-depleted serum. The insulin-effect, however, remained unchanged. The results suggest that insulin may regulate the de novo synthesis of HMG-CoA reductase and accordingly sterol synthesis at a post-transcriptional level.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0428
    Keywords: Keywords Leptin ; obesity ; brown fat ; transgenic mice ; insulin resistance ; hyperphagia ; leptin resistance.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With the exception of ob/ob mice, circulating plasma leptin is elevated in all other obese rodents as well as in obese humans, suggesting that leptin resistance rather than leptin deficiency is a characteristic feature of obesity. The exact molecular mechanisms leading to leptin resistance and the applicability of exogenous leptin to overcome resistance to the anorectic effect of the hormone, are insufficiently characterized. The aim of this study was to investigate whether chronic leptin administration could prevent the development of obesity and its associated disorders in transgenic mice with toxigene mediated ablation of brown adipose tissue (BAT). Daily injections of leptin were started at the age of 6 weeks, when body weight, food intake and plasma leptin levels of transgenics were not different from control mice. Over the next 6 weeks, leptin treated transgenics showed the same excessive body weight gain as transgenic mice injected with saline. Leptin treatment was furthermore not able to prevent the development of hyperphagia, hyperglycaemia, hyperinsulinaemia and hyperlipidaemia in transgenic mice. In contrast, control mice injected with leptin had significantly lower body weight, food intake and plasma triglycerides than those treated with saline. In summary, leptin treatment was not able to prevent the development of obesity and its associated abnormalities in transgenic mice with BAT deficiency. This data suggests that intact BAT function is of critical importance for leptin's effect on food intake and energy expenditure, and that primary dysfunction of BAT is associated with leptin resistance, even when hyperleptinaemia is not yet present. [Diabetologia (1997) 40: 810–815]
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 56 (1978), S. 423-423 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 52 (1974), S. 947-955 
    ISSN: 1432-1440
    Keywords: Affinity chromatography ; activators ; chylomicrons ; enzyme isolation ; heparin ; hyperlipoproteinemia ; inhibitors ; liver lipase ; lipoproteins ; lipoprotein lipase ; post-heparin lipolytic activity (PHLA) ; Affinitätschromatographie ; Aktivatoren ; Chylomikronen ; Enzymisolierung ; Heparin ; Hyperlipoproteinämien ; Inhibitoren ; Leberlipase ; Lipoproteine ; Lipoproteinlipase ; post-Heparin lipolytische Aktivität (PHLA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Chylomikronen sind spherische Makromoleküle mit einem Molekulargewicht von 1 × 109 bis 1 × 1010, die zu 80–95% aus Triglyzeriden, 2–10% aus Cholesterin, 3–5% aus Phospholipiden und 1–2% aus Protein bestehen. Sobald Chylomikronen aus dem ductus thoracicus in den Blutstrom gelangen, ändern sie ihre Eigenschaften sehr schnell. Sowohl Chylomicronen als auch VLDL bilden die Substrate für die sogenannte post-Heparin lipolytische Aktivität (PHLA). Hierbei handelt es sich um einen Komplex von enzymatischen Aktivitäten, die nach intravenöser Injektion von Heparin in den Blutkreislauf freigesetzt werden. Dieser Komplex besteht aus Enzymen, die sowohl Triglyzeride, Mono- und Diglyzeride als auch Phospholipide hydrolisieren. Bisher wurde angenommen, daß die Triglyzeridlipase im post-Heparin Plasma identisch mit der sogenannten Lipoproteinlipase sei. Untersuchungen mit hochgereinigten isolierten Enzymen erbrachten den Nachweis, daß zwei verschiedene Triglyzeridlipase-Aktivitäten am Abbau der Chylomikronen und VLDL beteiligt sind. Es konnte der Nachweis erbracht werden, daß es sich bei einer dieser Lipasen um eine Leber-Triglyzeridlipase handelt, während die zweite Triglyzeridlipase wahrscheinlich mit der Lipoproteinlipase aus dem Fettgewebe identisch ist. Bei beiden Enzymen handelt es sich um membrangebundene Enzyme, die erst nach Injektion von Heparin im Plasma meßbar werden. Im Gegensatz zur Lipoproteinlipase benötigt die Leberlipase in vitro eine hohe Kochsalzkonzentration (1 M) zur vollen Aktivität, während bei dieser Konzentration die Lipoproteinlipase zu mehr als 90% gehemmt wird. Während für die Lipoproteinlipase ein spezifischer Lipoproteincofaktor aus der Dichteklasse der VLDL isoliert werden konnte, ist ein solcher für die Leberlipase nicht notwendig.
    Notes: Summary Chylomicrons are spherical in appearance, range in molecular weight from 1 × 109 to 1 × 1010 and contain 80–95 per cent triglyceride, 2–10 per cent cholesterol, 3–5 per cent phospholipid, and 1–2 per cent protein. The properties of chylomicrons change rapidly once they enter the blood from the thoracic duct. Chylomicrons and VLDL are both substrates for post-heparin lipolytic activity (PHLA), a complex of enzymatic activities released by the parenteral administration of heparin. The complex of enzymes has been shown to consist of different activities, one of which is directed towards triglycerides and another towards mono-or diglycerides and phospholipids. The triglyceride lipase represents more than one enzyme derived from several tissue sources. One triglyceride lipase in post-heparin plasma has the properties of digesting artificial triglyceride emulsions more readily than chylomicrons in vitro and is more active in high sodium chloride concentrations than in physiological saline. This enzyme has been shown to derive from liver. Another lipase which is highly active against triglycerides of chylomicrons and is inhibited by high sodium chloride concentrations is present in adipose tissue and contrary to the liver lipase requires a lipoprotein cofactor for full activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 56 (1978), S. 99-110 
    ISSN: 1432-1440
    Keywords: Hyperlipoproteinemia ; Atherosclerosis ; Hypolipidemic agents ; Cholestyramine ; Clofibrate ; D-thyroxine ; Nicotinic acid ; Sitosterol ; Hyperlipoproteinämie ; Arteriosklerose ; lipidsenkende Medikamente ; Cholestyramin ; Clofibrat ; D-Thyroxin ; Nicotinsäure ; Sitosterin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Cardiovasculäre Erkrankungen sind die Haupttodesursache in den westlichen Ländern. Es ist erwiesen, daß Erhöhungen der Serumlipide zur frühzeitigen Entstehung der Arteriosklerose beitragen. Mit der Klassifikation der Hyperlipoproteinämien entstand die Grundlage für gezielte diätetische und pharmakologische Behandlungskonzepte zur Senkung der Serumlipidkonzentrationen. Es werden die Ergebnisse medikamentöser und diätetischer Präventivstudien diskutiert und die Erkenntnisse über den Stoffwechsel der Lipoproteine sowie Wirkungsweise und Nebenwirkungen der gebräuchlichsten lipidsenkenden Medikamente dargestellt. Es ist zum gegenwärtigen Zeitpunkt berechtigt, Patienten mit besonderer Disposition zur frühzeitigen Arteriosklerose diätetisch und medikamentös zu behandeln.
    Notes: Summary Cardiovascular disease has become the major cause of death in the Western countries. There is strong evidence that elevations of serum lipids contribute to the pathogenesis of premature atherosclerosis. The classification of the hyperlipoproteinemias has been most beneficial as a guide to development of dietary and pharmacological regimens for lowering serum lipid concentrations. The results of dietary and drug prevention trials are discussed. Insight into the mechanisms involved in lipoprotein metabolism as well as the mode of action and of side-effects of hypolipidemic drugs is reviewed. Using present knowledge of heart disease research, it is reasonable to suggest dietary and drug treatments for the high risk patient.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 56 (1978), S. 457-460 
    ISSN: 1432-1440
    Keywords: Type V hyperlipoproteinemia ; Coronary heart disease ; Differential diagnosis ; Selective enzyme defect ; Hyperlipoproteinämie Typ V ; Koronare Herzkrankheit ; Differentialdiagnose ; selektiver Enzymdefekt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei zwei Patienten mit primärer Hyperlipoproteinämie Typ V mit typischem klinischen Verlauf einschließlich rezidivierender Abdominalkoliken wurde ein Myokardinfarkt diagnostiziert. Die anschließend durchgeführte Koronarangiographie erbrachte in beiden Fällen ein fortgeschrittenes Drei-Gefäß-Leiden. Die vorgelegten Fallberichte zeigen, daß die Hyperlipoproteinämie Typ V mit einem höheren Erkrankungsrisiko an koronarer Herzkrankheit belastet ist, als bisher angenommen wurde. Es wird darauf hingewiesen, daß bei jeder Oberbauchkolik, auch bei jüngeren Typ V-Patienten, ein Myokardinfarkt ausgeschlossen werden muß. Die pathogenetische Bedeutung der auch bei diesen Patienten gefundenen selektiven Erniedrigung der Aktivität der Lipoproteinlipase wird diskutiert.
    Notes: Summary In two patients with primary Type V hyperlipoproteinemia with typical clinical features including recurrent bouts of abdominal pain a myocardial infarction was diagnosed. In both cases coronary angiography revealed a severe three vessel disease. The case reports demonstrate that the incidence of ischemic heart disease in patients with Type V hyperlipoproteinemia is higher than reported in the literature. In each case of severe abdominal pain, even in younger Type V patients, a myocardial infarction has to be excluded. In both patients a selective depression in the activity of lipoprotein lipase was found. The possible pathogenetic implication of this finding will be discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 55 (1977), S. 149-160 
    ISSN: 1432-1440
    Keywords: Human lipoproteins ; Apolipoproteins ; Primary structure ; Lipid protein-interactions ; Protein-protein-interactions ; Hydrophobic effect ; Amphipathic helices ; Lipoprotein models ; Membrane proteins ; Menschliche Lipoproteine ; Apolipoproteine ; Primärstruktur ; Lipid-Protein-Wechselwirkungen ; Protein-Protein-Wechselwirkungen ; Hydrophober Effekt ; amphipathische Helices ; Lipoprotein-Modelle ; Membranproteine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die menschlichen Plasmalipoproteine sind komplexe makromolekulare Strukturen, die eine entscheidende Rolle im Fettransport und im Energie- und Membranstoffwechsel tierischer Organismen spielen. Die strukturellen und funktionellen Wechselbeziehungen zwischen den einzelnen Lipoproteinklassen sind in den letzten Jahren eingehend untersucht worden. Ihre Proteinbestandteile, die sog. Apolipoproteine, konnten gereinigt und charakterisiert werden; die Primärstruktur von vier von ihnen ist bekannt. Erste Rekombinationsstudien deuteten darauf hin, daß das (unfraktionierte) Apoprotein ein beachtliches Lipid-Bindungsvermögen besitzt und daß dabei Partikel gebildet werden, die den nativen Lipoproteinen ähnlich sind. Spätere Bindungsexperimente, die in einer Reihe von Laboratorien mit den gereinigten A- und C-Apolipoproteinen und verschiedenen, physiko-chemisch gut definierten Lipiden durchgeführt wurden, haben zur Identifizierung von sog. Lipidbindungsstellen (lipid binding sites) innerhalb der Proteinmoleküle geführt. Bei und während der Wechselwirkung mit dem Lipid bilden sich dadurch sog. amphipathische Helices aus. Dieser für alle Apolipoproteine möglicherweise gleichermaßen gültige Mechanismus einer Lipid-Protein-Wechselwirkung bildet die Grundlage eines kürzlich vorgeschlagenen Modells einer der Lipoproteinklassen, nämlich der high density Lipoproteine (HDL). Die Bedeutung von Protein-Protein-Wechselwirkungen für die Bildung und Stabilisierung der Lipoproteine ist noch unbekannt. Ob eine Störung der Lipid-Protein-Wechselwirkungen zu strukturellen und/oder funktionellen Änderungen der entsprechenden Lipoproteine führen kann, wird noch diskutiert. Ob entsprechende Defekte zur Entstehung einer Hyperlipoproteinämie beitragen können, ist ebenfalls noch offen. Die einschlägige Literatur wird in der vorliegenden Arbeit besprochen, und die Fragen der physiologischen Relevanz dieser Studien und ihrer klinischen Aspekte werden diskutiert.
    Notes: Summary The plasma lipoproteins are complex macromolecular structures which play an essential role in fat transport and in energy and membrane metabolism of higher organized organisms. Much has been learned in the last decade about the structural and functional interrelationships of the different lipoprotein classes. Their protein moieties, the so-called apolipoproteins, have been purified and characterized, the primary structure of four of them is known. Initial recombination experiments showed a considerable potential of the (unfractionated) lipoprotein protein to bind to lipids and to form particles similar to native lipoproteins. Further binding experiments performed in several laboratories with the purified A- and C-apolipoproteins and different physico-chemically well defined lipids have lead to the identification of lipid binding sites within the protein molecules and the formation of amphipathic helices upon and during lipid binding. This possible common mechanism of lipid-protein fractions forms the basis of a recently proposed model of one lipoprotein class, namely the high density lipoproteins (HDL). The significance of protein-protein-interactions in the formation and maintenance of these lipoprotein particles is still unknown. Whether disturbed lipid protein interactions lead to structural and/or functional alterations of the corresponding lipoproteins is a topic of discussion. The pertinent literature is listed in this paper and the physiological relevance of these studies and their clinical aspects will be presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 62 (1984), S. 193-202 
    ISSN: 1432-1440
    Keywords: Diuretics ; Beta-blockers ; Alpha-adrenergic drugs ; Plasma lipids ; Triglyceride and cholesterol metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hypertension, hyperlipidaemia and cigarette smoking are major risk factors in coronary heart disease. Since many antihypertensive drugs alter plasma lipid levels it is a subject of current discussion that these agents may increase associated coronary risk and therefore offset the beneficial effects of lowering blood pressure. The purpose of this paper is to review clinical and experimental data in the literature on the influence of antihypertensive drugs on lipid metabolism. The thiazides hydrochlorothiazide and chlorthalidone cause an elevation of plasma triglycerides and very low density lipoprotein (VLDL) but have little effect on total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL). The unspecific beta-blockers, e.g. propranolol, do not affect total cholesterol and LDL but increase total triglycerides and VLDL and decrease HDL. The changes of plasma lipids and lipoproteins caused by cardio-selective beta-blockers, e.g. atenolol and metoprolol, and unspecific beta-blockers with intrinsic sympathomimetic activity (ISA), e.g. oxprenolol and pindolol, appear to be qualitatively similar but less pronounced. The alpha1-blocker prazosin reduces total triglycerides and slightly lowers total cholesterol. The concentration of VLDL plus LDL decreases while HDL may increase. Only very few studies have been reported on the effects of other antihypertensive drugs, e.g. clonidine, hydralazine, on plasma lipids. Several experimental studies reveal that antihypertensive agents exert direct effects on triglyceride and cholesterol metabolism. Although the pathophysiological mechanisms and the significance of the alterations of lipid metabolism induced by antihypertensive drugs are not yet clear, the following guidelines for the clinical use of these agents are recommended: (1) before initiating drug treatment in hypertensive patients, blood lipid levels should be measured to exclude a preexisting hyperlipidaemia, (2) during long-term therapy with antihypertensive agents, lipoprotein fractions should be controlled in order to reconsider the therapeutic regime if major alterations of blood lipid levels are observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 67 (1989), S. 50-50 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-1440
    Keywords: HIV infection ; AIDS ; Pneumocystis carinii pneumonia ; Pentamidine inhalation ; Prophylaxis ; Pneumocystoma ; Nodular infiltrates ; Pulmonary masses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Atypical pulmonary manifestations of Pneumocystis carinii infection and fair numbers of extrapulmonary and disseminated infections have lately been documented in patients with human immunodeficiency virus infection treated prophylactically with inhalative pentamidine. We report the case of a 32-year-old homosexual patient who was assessed for complaints of night sweats, weight loss, and progressive malaise. The patient denied any respiratory tract symptoms such as cough, sputum production, pleuritic chest pain, or shortness of breath. Chest X-ray revealed two large round noncavitating lesions in the lower lobe of the right lung. Pneumocystomas were diagnosed by fine-needle aspiration. A 3-week course of intravenous high-dose cotrimoxazole resulted in amelioration of symptoms but no change in the radiographic appearance of the pulmonary lesions. Four months later the patient is alive and stable and is being treated with pentamidine inhalation of 300 mg per 2 weeks and two tablets of pyrimethamine sulfadoxine per week.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...