9 results on '"cell metabolism"'
Search Results
2. Mathematical Modeling and Simulation Provides Evidence for New Strategies of Ovarian Stimulation
- Author
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Toni Mancini, Susanna Röblitz, Sophie Fischer, Tillmann H.C. Kruger, Marcel Egli, Enrico Tronci, Rainald Ehrig, Brigitte Leeners, Stefan Schäfer, Fabian Ille, University of Zurich, and Röblitz, Susanna
- Subjects
0301 basic medicine ,endocrine system ,Computer science ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,media_common.quotation_subject ,Stimulation ,610 Medicine & health ,Luteal phase ,Bioinformatics ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,Modeling and simulation ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Ovarian Follicle ,Ovulation Induction ,Follicular phase ,medicine ,Humans ,Computer Simulation ,Pharmacokinetics ,Fertility preservation ,Menstrual cycle ,Menstrual Cycle ,media_common ,Original Research ,030219 obstetrics & reproductive medicine ,Assisted reproductive technology ,assisted reproductive technologies ,lcsh:RC648-665 ,Therapies, Investigational ,endocrinological networks ,Reproduction ,Cell Metabolism ,systems biology ,follicular dynamics ,ordinary differential equations ,Fertility Agents, Female ,Models, Theoretical ,10175 Clinic for Reproductive Endocrinology ,Diabetes and Metabolism ,2712 Endocrinology, Diabetes and Metabolism ,030104 developmental biology ,Time course ,Female - Abstract
New approaches to ovarian stimulation protocols, such as luteal start, random start or double stimulation, allow for flexibility in ovarian stimulation at different phases of the menstrual cycle which is especially useful when time for assisted reproductive technology is limited, e.g. for emergency fertility preservation in cancer patients. It has been proposed that the success of these methods is based on the continuous growth of multiple cohorts ("waves") of follicles throughout the menstrual cycle which leads to the availability of ovarian follicles for ovarian controlled stimulation at several time points. Though several preliminary studies have been published, their scientific evidence has not been considered as being strong enough to integrate these results into routine clinical practice. This work aims at adding further scientific evidence about the efficiency of variable-start protocols and underpinning the theory of follicular waves by using mathematical modelling and numerical simulations. For this purpose, we have modified and coupled two previously published models, one describing the time course of hormones and one describing competitive follicular growth in a normal menstrual cycle. The coupled model is used to test stimulation protocols in silico. Simulation results show the occurrence of follicles in a wave-like manner during a normal menstrual cycle and qualitatively predict the outcome of ovarian stimulation initiated at different time points of the menstrual cycle.
- Published
- 2021
3. MITOCHONDRIOPATHIEN
- Author
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Roesti, Andreas
- Published
- 2016
- Full Text
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4. Bedeutung apoptotischer Prozesse für die Strahlentherapie. Teil I.
- Author
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Abend, M and van Beuningen, D
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CELL metabolism ,PROTEIN metabolism ,REACTIVE oxygen species ,APOPTOSIS ,CELLS ,CELLULAR signal transduction ,COMPARATIVE studies ,DNA ,FLOW cytometry ,RESEARCH methodology ,MEDICAL cooperation ,NECROSIS ,ONCOGENES ,PROTEOLYTIC enzymes ,PULSED-field gel electrophoresis ,RADIOTHERAPY ,RESEARCH ,TRANSFERASES ,TUMORS ,EVALUATION research ,IN vitro studies ,PHYSIOLOGICAL effects of radiation - Abstract
According to a considerable amount of publications apoptosis plays an important role for radio- and chemotherapy. The most important results related to this issue will be described in 2 independent articles, covering the following topics: Part I: I. definition, morphology, biochemical processes, II. clinical relevant detection assays, III. signal transduction. Part II: significance of apoptosis for radio- and chemotherapy. [ABSTRACT FROM AUTHOR]
- Published
- 1998
5. Über die Wirkung der Glucocorticoide und der Mineralcorticoide auf Stoffwechsel und Wachstum von Zellen mesenchymalen sowie epithelialen Ursprungs.
- Author
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Rasche, B. and Ulmer, W.
- Abstract
Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1970
- Full Text
- View/download PDF
6. Zur Wirkung der Glucocorticoide auf permanente Fibroblastenkulturen bei Dauerbehandlung (Wachstum, Morphologie, Zellstoffwechsel).
- Author
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Rasche, B., Leder, L., and Ulmer, W.
- Abstract
Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1967
- Full Text
- View/download PDF
7. Hyaluron für die Haut.
- Subjects
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CELL metabolism , *WRINKLES (Skin) , *HUMAN body , *HYALURONIC acid , *EXERCISE - Abstract
The article reports that aging process slows down cell metabolism, and the hyaluronic acid (HA) synthesis in human body. It notes that skin fibers do not produce enough water and wrinkles. It adds that the synthesis and breakdown of HA in the body is about a dynamically balanced process. It states that the study was conducted in 2015 on 33 volunteers who usually exercise very intensely.
- Published
- 2018
8. Untersuchung metabolischer Netzwerke mit Verbandstheorie
- Author
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Goldstein, Yaron
- Subjects
lattice theory ,flux cou- pling ,models ,general framework ,cell metabolism ,reaction double knockout ,reaction pathways ,target - Abstract
Ziel dieser Arbeit ist es, metabolische Netzwerke und Zellstoffwechselpfade durch eine algebraische Struktur zu beschreiben. Mit dieser sollen Untersuchungsmethoden entwickelt werden, die so formuliert sind, dass sie einfach für verschiedene qualitative Modelle genutzt werden können. In der Vergangenheit diente häufig ein Kegel als mathematische Grundlage, um die stationären Zustände des Stoffwechsels zu untersuchen. Konzepte wie elementare Flussmoden, Flusskopplungsuntersuchung (FCA) und Minimal Cut Sets wurden basierend auf diesem Flusskegel eingeführt. Diese Arbeit soll Modellierungskonzepte und Anwendungen identifizieren, die sich auf unsere abstrakte Form übertragen lassen, und so ein verallgemeinertes Framework vorstellen, mit dem der Zellstoffwechsel qualitativ untersucht werden kann. Reaktionenmengen, die gemeinsam im Stoffwechsel wirken können, werden durch Elemente eines Vereinigungsverbands repräsentiert. Elementarmoden werden qualitativ beschrieben und auf verbandstheoretische Konzepte übertragen. Basierend auf existierenden Algorithmen zur FCA wird ein Verfahren entwickelt, mit dem das maximale Element im Verband sehr schnell gefunden wird. Mit Hilfe dieses Maximums wird eine abstrakte, qualitative Flusskopplung definiert. Der zugehörige Algorithmus wurde implementiert und vollständige Reaktionen- Doppelknockouts (EFCA) wurden für verschiedene Zellmodelle erstmalig simuliert. Die Implementierung wirkt auf stationären Zuständen des Zellstoffwechsels, die um thermodynamische Nebenbedingungen ergänzt werden können. Weiterhin wird ein Konzept zur Target Prediction mittels Maximum- Berechnung vorgestellt und der Zusammenhang zu Cut Sets diskutiert. Insgesamt stellt sich heraus, dass die bekanntesten Analysemethoden des Stoffwechsels zu den speziellsten Elementen im Verband korrespondieren. Es wird gezeigt, dass dem Standardmodell der stationären Zustände sowie zwei weiteren Modellen - Hyperpfade und ein logisches Modell - Verbände zugrundeliegen. Je nach Anwendungsfall entsprechen Elementarmoden den minimalen oder den unzerlegbaren Elementen im Verband. Im Starbucks-Lemma wird gezeigt, dass sich mit diesen Elementen in vielen Modellkonzepten einfach arbeiten und sich Flusskopplung sogar für jedes qualitative Modell definieren lässt. Verschiedene Schreibweisen des Verbandsmaximums ergeben schließlich ein leicht verständliches Verfahren, das für alle Modelle gültig ist. Es kann gezeigt werden, dass die vorgestellte Implementierung für das Standardmodell ähnlich schnell wie die besten bekannten FCA-Algorithmen ist. Es ergibt sich sogar, dass wesentliche Laufzeitverbesserungen nur noch durch effizientere Programmierung erreicht werden sollten. Verbandstheoretisch formuliert lassen sich viele Fragen einfacher beantworten, da der Bezug zu bekannten Ergebnissen klarer wird. Damit ist das Framework der Verbandstheorie exzellent dafür geeignet, qualitative Fragen zu beantworten und Untersuchungsverfahren zu optimieren oder neu zu entwickeln., This thesis aims to describe metabolic networks and reaction pathways in the cell using an algebraic structure. On this basis we want to establish analytical methods that can be used for a variety of approaches in qualitative modeling. To analyze the metabolism, the steady state flux cone is presently the most commonly used mathematical model. Concepts such as elementary flux modes, flux coupling analysis (FCA) and minimal cut sets have been introduced based on this flux cone. This thesis identifies modeling approaches and their applications based on the developed abstract algebraic structure -- thus introducing a general framework for qualitative analysis of the metabolism. Reaction sets that can be simultaneously active in a cell are represented as the elements of a join (semi)lattice. A qualitative description of elementary flux modes is given and the concepts used are translated in lattice theory. Partially based on existing FCA algorithms, a method is presented that can rapidly identify the maximum of a lattice. This maximum is then used to define an abstract term of flux coupling that can be applied to a diversity of qualitative models. The implemented algorithm is applied to simulate a complete reaction double knockout (EFCA) in different cell models. These models are based on a steady state assumption that can be combined with further thermodynamic constraints. Additionally a concept of target prediction is introduced, utilizing the calculation of lattice maxima, and related to (minimal) cut sets. Taken as a whole, it can be said that the most known analytical approaches for the metabolism correspond perfectly well to the most special elements of join lattices. We are able to apply lattice theory to both the standard model based on the flux cone, pathways through hyper graphs and a model using logic formulas. It becomes apparent that this logic model is a relaxation of the standard model. Depending on the application, the elementary flux modes are shown to be either the minimal or the irreducible elements of a lattice. The Starbucks lemma proves that both these sets can be easily worked with in many qualitative models. It further proves our FCA algorithm is correct for literally all kinds of qualitative models. We will show that our implementation, even though much easier to adapt to other models, has a running time comparable to well-established FCA algorithms. As a matter of fact we will see that further improvements of speed are most likely reachable only by more efficient ways of programming, not by more effective theoretical approaches. Using lattice theory it is much easier to answer many open questions about the cell's metabolism. One reason for this is that it becomes easier to apply known results from certain models on other ones. Hence, the general framework of lattice theory is perfectly suited for qualitative modeling and to develop or optimize analytical methods.
- Published
- 2013
9. 274. Schmerz bei Durchblutungsstörung - Ein Stoffwechselproblem.
- Author
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Elert, O.
- Abstract
Copyright of Langenbecks Archiv fuer Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1980
- Full Text
- View/download PDF
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