Dissertations / Theses on the topic 'Resorption'
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1
Hunziker, Renate. "Die Resorption intrazerebraler Hämatome /." [S.l : s.n.], 1987. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Wedenberg, Cecilia. "Development and morphology of internal resorption of teeth a study in humans, monkeys and rats /." Stockholm : Kongl Carolinska Medico Chirurgiska Institutet, 1987. http://catalog.hathitrust.org/api/volumes/oclc/16149996.html.
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Pierce, Angela Mary. "Cellular mechanisms in bone and tooth resorption morphological studies in rats and monkeys /." Stockholm : Kongl. Carolinska Medico Chirurgiska Institutet, 1988. http://books.google.com/books?id=usBpAAAAMAAJ.
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Dreyer, Craig William. "Clast cell activity in a model of aseptic root resorption." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phd778.pdf.
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Heath, J. K. "Studies on cellular interactions in bone resorption." Thesis, Anglia Ruskin University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354876.
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McCauley, Laurie Kay. "Cellular mechanisms of lymphocyte-mediated bone resorption /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487759055156174.
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Stutzer, Andre. "Retinoid induced bone resorption, model and application /." [S.l.] : [s.n.], 1987. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Low, Eva Oi Wha. "Cellular And Molecular Control Of Root Resorption." Thesis, Faculty of Dentistry, 2003. http://hdl.handle.net/2123/4401.
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Koval, Anna. "Reabsorção dentária." Master's thesis, [s.n.], 2015. http://hdl.handle.net/10284/5089.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaEste trabalho científico no âmbito de conclusão do curso de Mestrado Integrado em Medicina Dentária na Universidade Fernando Pessoa teve como principal objetivo, a realização de uma revisão bibliográfica acerca de reabsorções dentárias. Os objetivos particulares foram: classificar na sua generalidade as reabsorções dentárias, analisar a etiologia, o diagnóstico, realçar as possíveis opções de tratamento e follow up. Demonstrar a importância de efetuar um correto diagnóstico para posterior tratamento mais adequado. Conhecer e reconhecer as complicações desta situação, bem como alertar para o indispensável acompanhamento que estas e as restantes lesões requerem, dar a conhecer os protocolos de atuação perante as diferentes lesões. A pesquisa bibliográfica centrou-se em artigos científicos publicados entre os anos (1999-2015), em revistas internacionais com artigos científicos dedicados às reabsorções dentárias. Os motores de busca on-line consultados foram “PubMed”, “B-on” e “Science Direct” com as palavras-chave: “Root resorption”, “Dental resorption”, “ Cervical resorption” External resorption”, “Internal resorption”, “Endodontic treatment for root resorption”, “Pharmacological treatment for root resorption”, “Dental enucleation”, “Dental concussion”, “Management of avulsed teeth”, “Cyts and tumors causing root resortion” “pulp infecion”, “Management for internal root resorption” “Concept of root resorption”,”Phisiologyc root resorption”,” Dental trauma”. Foram também pesquisados livros em biblioteca dedicados a este assunto. A elaboração de uma boa história clínica, que reúne todos os dados imprescindíveis para a realização de um correto diagnóstico e plano de tratamento, poderão fazer toda a diferença perante a previsão das possíveis complicações e prognóstico do caso. Ter consciência acerca da gravidade destas questões permite fazer de forma segura as recomendações necessárias. As reabsorções dentárias podem influenciar a vida dos indivíduos, alterando a sua aparência, a fala e a posição dos dentes podendo causar problemas físicos, sociais, funcionais, estéticos e psicológicos. Desta forma a sua abordagem requer um bom senso, experiência e habilidade. This scientific work was conducted under the completion of the degree of MSc of Dental Medicine at the University Fernando Pessoa and had as main objective the achievement of a literature review about dental resorption. The particular objectives were: classify in general dental resorption, analyze the etiology, diagnosis, highlight the possible treatment options and follow-up. Demonstrate the importance of making a correct diagnosis for further appropriate treatment. Know and recognize the complications of this situation and the follo-up of this injuries require, describe the treatment guidelines for different injuries. The literature search focused on scientific papers published in international journals devoted to dental resorption in the past few years (2010-2015). The online search engines were "PubMed", "Bon" and "Science Direct" with the keywords: "Root resorption," "Dental resorption," "Cervical resorption" External resorption, "" Internal resorption " "Endodontic treatment for root resorption," "Pharmacological treatment for root resorption," "Dental enucleation", "Dental concussion", "Management of avulsed teeth", "CYTS and tumors causing root resortion" "pulp infecion", "Management for internal root resorption "" Concept of root resorption, "" Phisiologyc root resorption, "" Dental trauma ". Books dedicated to this subject were also searched. The development of a good clinical history that gathers all the essential data for achieving a correct diagnosis and treatment plan can make all the difference to the prediction of possible complications and prognosis of the case. Having awareness of the seriousness of these issues allows you to safely make appropriate recommendations. The dental resorption can influence the people lives, changing their appearance, speech and the position of the teeth which can cause physical problems, social, functional, aesthetic and psychological. Thus, the clinical approach requires wisdom, experience and ability.
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Langstaff, Sarah Dorthea. "Calcium phosphate ceramics capable of supporting osteoclastic resorption." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0005/NQ42953.pdf.
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Bernhold, Brechter Anna. "Kinins : important regulators in inflammation induced bone resorption." Doctoral thesis, Umeå : Univ, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-959.
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Moroz, Adam. "Reduced order modelling of bone resorption and formation." Thesis, De Montfort University, 2011. http://hdl.handle.net/2086/5409.
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The bone remodelling process, performed by the Bone Multicellular Unit (BMU) is a key multi-hierarchically regulated process, which provides and supports various functionality of bone tissue. It is also plays a critical role in bone disorders, as well as bone tissue healing following damage. Improved modelling of bone turnover processes could play a significant role in helping to understand the underlying cause of bone disorders and thus develop more effective treatment methods. Moreover, despite extensive research in the field of bone tissue engineering, bonescaffold development is still very empirical. The development of improved methods of modelling the bone remodelling process should help to develop new implant designs which encourage rapid osteointegration. There are a number of limitations with respect to previous research in the field of mathematical modelling of the bone remodelling process, including the absence of an osteocyte loop of regulation. It is within this context that this research presented in this thesis utilises a range of modelling methods to develop a framework for bone remodelling which can be used to improve treatment methods for bone disorders. The study concentrated on dynamic and steady state variables that in perspective can be used as constraints for optimisation problem considering bone remodelling or tissue remodelling with the help of the grafts/scaffolds.The cellular and combined allosteric-regulation approaches to modelling of bone turnover, based on the osteocyte loop of regulation, have been studied. Both approaches have been studied different within wide range of rate parameters. The approach to the model validation has been considered, including a statistical approach and parameter reduction approach. From a validation perspective the cellular class of modes is preferable since it has fewer parameters to validate. The optimal control framework for regulation of remodelling has been studied. Future work in to improve the models and their application to bone scaffold design applications have been considered. The study illustrates the complexity of formalisation of the metabolic processes and the relations between hierarchical subsystems in hard tissue where a relatively small number of cells are active. Different types/modes of behaviour have been found in the study: relaxational, periodical and chaotic modes. All of these types of behaviour can be found, in bone tissue. However, a chaotic or periodic modes are ones of the hardest to verify although a number of periodical phenomena have been observed empirically in bone and skeletal development. Implementation of the allosteric loop into cellular model damps other types of behaviour/modes. In this sense it improves the robustness, predictability and control of the system. The developed models represent a first step in a hierarchical model of bone tissue (system versus local effects). The limited autonomy of any organ or tissue implies differentiation on a regulatory level as well as physiological functions and metabolic differences. Implementation into the cellular phenomenological model of allosteric-like loop of regulation has been performed. The results show that the robustness of regulation can be inherited from the phenomenological model. An attempt to correlate the main bone disorders with different modes of behaviour has been undertaken using Paget’s disorder in bone, osteoporosis and some more general skeleton disorders which lead to periodical changes in bone mass, reported by some authors. However, additional studies are needed to make this hypothesis significant. The study has revealed a few interesting techniques. When studying a multidimensional phenomenon, as a bone tissue is, the visualisation and data reduction is important for analysis and interpretation of results. In the study two novel technical methods have been proposed. The first is the graphical matrix method to visualise/project the multidimensional phase space of variables into diagonal matrix of regular combination of two-dimensional graphs. This significantly simplifies the analysis and, in principle, makes it possible to visualise the phase space higher than three-dimensional. The second important technical development is the application of the Monte-Carlo method in combination with the regression method to study the character and stability of the equilibrium points of a dynamic system. The advantage of this method is that it enables the most influential parameters that affect the character and stability of the equilibrium point to be identified from a large number of the rate parameters/constants of the dynamic system. This makes the interpretation of parameters and conceptual verification of the model much easier.
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Lu, Yiji. "A resorption cogeneration cycle for power and refrigeration." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3515.
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Heat-driven energy system attracts ever increasing attentions to improve the efficiency of overall energy utilisation by recovering the heat energy such as solar thermal energy, wasted heat from industry and geothermal energy. Adsorption technology is recognised as one of the promising solutions to convert low-grade heat to refrigeration or be used as heat pump. Based on the working principle of this technology, it can promisingly be developed into combined refrigeration and power generation system by integrating an expander in to the system. However, due to the limited research efforts on the system investigation, refrigeration generation by adsorption technology is still immature. The investigation on the working conditions of the system, the selection of proper expansion machine for power generation part of the cogeneration and overall system evaluation are important to be conducted. This study aims to explore the feasibility of integration the adsorption technology with expansion machine for refrigeration and power generation. The proposed cogeneration combines resorption system, which has potentially twice of the cooling capacity compared with conventional adsorption system, integrated with expansion machine to continuously produce refrigeration and power. The design and optimisation methods of the proposed system were studied in order to select the proper resorption working pairs under different heat source conditions. Furthermore, the system performance with and without the optimisation methods were evaluated by the first and second law analysis. Results indicated attractive performance and MnCl2-SrCl2 was stood out as the optimal resorption working pair for the purpose of high refrigeration generation under low grade heat source, when ammonia is the working fluid in the system. Scroll expander was selected as the expander to be explored in this study because of its highest average isentropic efficiency, low cost, low vibration noise, high availability and easy modification from compressor to expander for our special application demand. A lab scale scroll expander test rig was designed, constructed and tested to obtain the performance such as isentropic efficiency and electrical efficiency of a selected scroll machine under various working conditions. An assessment of a case study of the resorption cogeneration system was conducted to evaluate the variation of the power and refrigeration performance with the time. Results indicated that a resorption cogeneration with 25.2 kg MnCl2 and 18.9 kg SrCl2 could potentially produce 1 kW power and 2.5 kW cooling capacity when the cycle time is around 25 minutes.
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Ljunggren, Östen. "Involvement of bradykinin in inflammation induced bone resorption." Umeå : University of Umeå, 1991. http://catalog.hathitrust.org/api/volumes/oclc/24493228.html.
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Korhonen, T. (Tommi). "Bone flap survival and resorption after autologous cranioplasty." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526222530.
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Abstract This thesis evaluated the factors affecting bone flap survival and bone flap resorption after primary cranial reparation surgery, cranioplasty, conducted to repair a cranial bone defect with an autologous cryopreserved bone flap. Emphasis is put on the predictors, progression, and definition of an important yet poorly understood postoperative complication, bone flap resorption. Study I assessed the rates and predictors of bone flap removal and bone flap resorption in a Finnish retrospective multicentre setting. 40% of patients developed complications of whom half required bone flap removal. Bone flap resorption and surgical site infections were the underlying cause in 90% of bone flap removal surgeries. The prevalence of both surgical site infections and bone flap resorption was 9%. In summary, young age was found to predict bone flap resorption and smoking predisposed patients to infections requiring bone flap removal. Study II applied computed tomography-based volumetry to evaluate the prevalence of subclinical bone flap resorption and to monitor its progression. In the follow-up, 90% of patients were found to have decreased bone flap volumes indicating varying degrees of resorption. However, the progression of bone flap resorption as a function of follow-up time was non-linear on the cohort level, and thus routine radiological follow-up seems unjustified. Most bone flaps do not appear to resorb enough to require removal even in the long-term follow-up. Study III addressed the unclarity in the definition of bone flap resorption. The computed tomography-based Oulu Resorption Score was developed to standardise the interpretation of radiological bone flap resorption and to guide follow-up interventions. The score values range from 0 to 9 with increasing values implying more severe bone flap resorption. Coupled with radiological evaluation conducted by independent neurosurgeons, an Oulu Resorption Score of ≥5 was defined to be clinically relevant. Further, the scores were divided into four grades based on the recommended follow-up procedures. Grades 0 (score 0) and I (scores 1 to 4) require no additional follow-up, but those with a grade II (score 5 to 8) or III (score 9) should be referred to neurosurgical consultation with reoperation considered at least in cases of grade III bone flap resorptionTiivistelmä Tässä väitöstyössä selvitettiin potilaan omalla kylmäsäilytetyllä luuistutteella tehtyjen kallon luupuutosten ensikertaisten korjausleikkausten tuloksiin vaikuttavia tekijöitä. Erityisesti tarkasteltiin luuistutteen liukenemisen, erään tärkeän, joskin heikosti ymmärretyn komplikaation ennustavia tekijöitä, etenemistä ja määritelmää. Tutkimuksessa I selvitettiin luuistutteen poiston ja liukenemisen yleisyyttä ja näihin vaikuttavia tekijöitä suomalaisessa takautuvassa monikeskusaineistossa. Potilaista 40 %:lle kehittyi komplikaatio. Komplikaatioista puolet johti istutteen poistoon. Luuistutteen liukeneminen ja leikkausalueinfektiot muodostivat 90 % poistoon johtaneista komplikaatioista. Sekä infektioiden että istutteen liukenemi¬sen esiintyvyys oli 9 %. Nuori ikä altisti istutteen liukenemiselle ja tupakointi leikkausalueinfektiolle. Tutkimuksessa II sovellettiin tietokonetomografiaan perustuvaa tilavuusmittausta luuistutteen oireettoman liukenemisen esiintyvyyden ja etenemistaipumuksen selvittämiseksi. Seurannassa 90 %:lla potilaista todettiin alentunut luuistutteen tilavuus viitaten asteeltaan vaihtelevaan istutteen liukenemiseen. Koko tutkimusjoukon tasolla istutteiden liukeneminen ei kuitenkaan edennyt lineaarisesti seuranta-ajan funktiona, joten rutiininomainen seuranta kuvantamistutkimuksin ei vaikuta perustellulta. Suurin osa luuistutteista liukeni niin vähän, ettei uutta leikkausta tarvittu pitkässäkään seurannassa. Tutkimuksessa III käsiteltiin luuistutteen liukenemisen nykyisellään epäselvää määritelmää ja kehitettiin uusi tietokonetomografiaan perustuva pisteytysjärjestelmä (Oulu resorption score) tarkoituksena vakioida radiologisten luuistutteen liukenemislöydösten tulkinta ja ohjata hoitolinjan valintaa. Pisteytysarvot vaihtelevat välillä 0-9. Kasvava arvo kuvaa luuistutteen liukenemisen vaikeusasteen kasvua. Luokitus yhdistettiin riippumattomien neurokirurgien radiologisiin arvioihin, joiden perusteella pistemäärä ≥5 määriteltiin kliinisesti merkitykselliseksi. Pistemäärät jaettiin neljään luokkaan suositeltujen jatkotoimenpiteiden mukaisesti. Luokkia 0 (0 pistettä) ja I (1–4 pistettä) vastaava luuistutteen liukeneminen ei vaadi jatkotoimenpiteitä. Luokkia II (5–8 pistettä) ja III (9 pistettä) vastaavasta luuistutteen liukenemisesta suositellaan konsultoitavan neurokirurgia. Uusintaleikkausta suositellaan harkittavan ainakin luokan III tapauksissa
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Neale, Susan Dorothy. "The role of macrophages in pathological bone resorption /." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09MSM/09msmn348.pdf.
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Autio, R. (Reijo). "MRI of herniated nucleus pulposus:correlation with clinical findings, determinants of spontaneous resorption and effects of anti-inflammatory treatments on spontaneous resorption." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514280954.
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The purpose of the current study was to evaluate the intercorrelations of magnetic resonance imaging (MRI) findings and clinical symptoms and signs in sciatic patients. Furthermore, determinants of spontaneous HNP resorption and the effect of anti-inflammatory treatments (periradicular methylprednisolone injection and intravenous infliximab) on spontaneous HNP resorption were evaluated.
MRI follow-up was performed at baseline, after two months, after six months and after one-year for patients with unilateral sciatica to evaluate determinants of spontaneous HNP resorption and the effect of periradicular methylprednisolone injection on spontaneous HNP resorption. At baseline the study population consisted of 160 patients (group A).
MRI follow-up for 21 patients with unilateral sciatica was performed at baseline and after two weeks, after three months and after six months to evaluate the effect of infliximab, a monoclonal TNFα antagonist, infusion on spontaneous HNP resorption (group B).
Patients in group A were randomized to receive either periradicular saline or methylprednisolone. Volume of HNP, extent and thickness of enhancement (in Gd-DTPA MRI) and degree of disc displacement were measured and the symptoms and signs were followed repeatedly. The extent of rim enhancement correlated significantly with the degree of disc displacement. The duration of sciatic symptoms correlated negatively with enhancement parameters. The clinical symptoms did not correlate significantly with the different enhancement parameters or disc herniation volume. Achilles reflex abnormality correlated significantly with all enhancement parameters for lesions at L5-S1.
Significant decrease in HNP volume occurred from baseline to two moths, and even more so during the whole one year follow-up period. Higher baseline scores of rim enhancement thickness, higher degree of HNP displacement in the Komori classification and age category of 41–50 years were associated with a higher resorption rate. Clinical symptoms alleviation occurred concordantly with a faster resorption rate.
No significant difference was noted in the decrease of HNP volume in the saline and methylprednisolone injection groups in follow-up imaging during one year. The enhancement parameters (thickness and extent of rim enhancement) did not differ significantly in the different treatment groups.
In group B, 11 patients received intravenous infliximab and 10 saline. Baseline demographic data, pain scores, and clinical status, did not differ between the treatment groups. HNP volume decreased significantly in both groups (P < 0.01). There was no significant difference in HNP volume changes between the treatment groups. By two weeks, enhancement thickness increased significantly in the infliximab compared placebo group (p=0.003). Two patients in each group required back surgery prior to the 6-month assessment.
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Lutz, Katharina. "Untersuchung zur Resorption von emulgiertem Vitamin E beim Ferkel." Diss., [S.l.] : [s.n.], 2006. http://edoc.ub.uni-muenchen.de/archive/00005467.
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Bilk, Sabine. "Mechnismen der anionischen SCFA-Resorption im Pansen des Schafes." Doctoral thesis, Universitätsbibliothek Leipzig, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:15-20080507-104442-9.
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Die im Reticulorumen als Endprodukte der mikrobiellen Fermentation in großen Mengen anfallenden und direkt resorbierten kurzkettigen Fettsäuren Acetat, Propionat und Butyrat spielen für den Wiederkäuer eine zentrale Rolle bei der Deckung seines Energiebedarfs. Trotz dieser herausragenden Bedeutung der SCFA-Resorption gibt es heute noch kein generell anerkanntes Modell für die Transportwege kurzkettiger Fettsäuren im Pansenepithel. In dieser Arbeit wurde die apikale Aufnahme von radioaktiv markiertem Acetat in das Pansenepithel gemessen. Acetat ist die mengenmäßig bedeutendste kurzkettige Fettsäure. Zusätzlich wurden elektrophysiologische Studien zur Erfassung des transepithelialen Kurzschlussstromes und der transepithelialen Leitfähigkeit mit Hilfe der Ussing-Kammer-Technik durchgeführt. Aufgrund der Tatsache, dass der extra- und intrazelluläre pH-Wert und die Aufnahme kurzkettiger Fettsäuren in das Pansenepithel einander gegenseitig beeinflussen, wurden zusätzlich Messungen des intrazellulären pH-Wertes an primärkultivierten Pansenepithelzellen durchgeführt. In Ergänzung der funktionellen Untersuchungen wurde das Vorhandensein potentieller SCFA-Transportproteine auf mRNA-Ebene molekularbiologisch untersucht. Bezüglich der anionischen Acetatresorption in das Pansenepithel des Schafes konnten folgende Befunde erhoben werden: ? Ein Teil der Acetataufnahme erfolgt bikarbonatabhängig. Dieser bikarbonatabhängige Mechanismus stellte sich im Rahmen der funktionellen Untersuchungen als nitrat- und nifluminsäuresensitiv dar. ? Ein weiterer Teil der Acetataufnahme erwies sich als bikarbonatunabhängig aber ebenfalls nitrat- und nifluminsäuresensitiv. ? Die Messungen des intrazellulären pH-Wertes (pHi) zeigten, dass der hemmende Einfluss von Nitrat auf die Acetataufnahme nicht durch eine Beeinflussung des pHi hervorgerufen wurde. Nifluminsäure veränderte zwar den pHi, die Untersuchungen der Acetataufnahme machten aber deutlich, dass Nifluminsäure keine additive Wirkung zu Nitrat hatte. ? Die Messung des transepithelialen Kurzschlussstromes (Isc) zeigte, dass es nach mukosaler Acetatzugabe in bikarbonatfreier Lösung zu einem signifikanten Abfall des Isc kam. Bei Berechnung der Acetatmenge, die diesem Isc-Abfall zugrunde lag, war festzustellen, dass dieser elektrogene Teil der bikarbonatunabhängigen Acetataufnahme wahrscheinlich nur ca. 3% der insgesamt erfolgten bikarbonatunabhängigen Acetataufnahme ausmacht. ? Im Rahmen der intrazellulären pH-Wertmessungen zeigte sich nach Entfernen von extrazellulärem Chlorid in HCO3--haltiger Lösung eine starke, reversible Alkalisierung der Zellen. ? Auf mRNA Ebene gelang erstmals der Nachweis der Carrierproteine DRA (SLC26A3),PAT1 (SLC26A6), SMCT1 (SLC5A8) und auch des CFTR sowie der potentiellen Anionenleitfähigkeiten ClC2, ClC4 und ClC5 im Pansenepithel des Schafes. ? Mit Hilfe der Semiquantifizierung konnte eine unterschiedliche Expression von NBC, MCT1,DRA und PAT1 auf mRNA-Ebene im Pansengewebe und in den primärkultivierten Pansenepithelzellen nachgewiesen werden. Dabei waren DRA und MCT1 im Pansengewebe, NBC und PAT1 hingegen in den kultivierten Pansenepithelzellen signifikant stärker exprimiert. Bei NHE1 und AE2 zeigten sich keine signifikanten Unterschiede zwischen Pansengewebe und kultivierten Pansenepithelzellen. Die Sensitivität der bikarbonatabhängigen und der bikarbonatunabhängigen Acetataufnahme gegenüber Nitrat und Nifluminsäure zeigte, dass an beiden Transportwegen ein (oder mehrere)Protein(e) beteiligt ist (sind). Damit konnte mit Hilfe der Uptake-Technik die Existenz eines SCFA-/HCO3--Austauschers weiter verifiziert werden. Der funktionelle Nachweis einer bikarbonatunabhängigen proteinvermittelten apikalen SCFA-Aufnahme stellt für das Pansenepithel eine völlig neue Erkenntnis dar. An den kultivierten Pansenepithelzellen konnten Hinweise für die Existenz eines Cl-/HCO3--Austauschers erhoben werden. Das Vorhandensein eines SCFA-/HCO3--Austauschers in den kultivierten Zellen kann aufgrund der hier durchgeführten Untersuchungen nicht eindeutig bestätigt werden, da die Veränderungen des pHi auch auf die Diffusion der undissoziierten Säure zurückgeführt werden können. Möglicherweise ist ein SCFA-/HCO3--Austauscher in den kultivierten Pansenepithelzellen aufgrund des Fehlens von SCFA im Kulturmedium herabreguliert.In der vorliegenden Arbeit konnten verschiedene Proteine (DRA, PAT1, CFTR, ClC2, 4 und 5 sowie SMCT1) erstmals auf mRNA-Ebene im Pansenepithel des Schafes nachgewiesen werden. Alle diese Proteine könnten potentiell am Transport von SCFA durch das Pansenepithel beteiligt sein. Eine vollständige Struktur-Funktions-Beziehung konnte in der vorliegenden Arbeit nicht geklärt werden. Bezieht man aber die Ergebnisse der Semiquantifizierung in die Betrachtung der Ergebnisse der pHi-Messung und der Ussing-Kammer Untersuchung mit ein, so wäre ein Modell denkbar, in dem der PAT1 vorwiegend als Cl-/HCO3--Austauscher, der DRA, der in den kultivierten Pansenepithelzellen im Rahmen der Semiquantifizierung nicht nachgewiesen werden konnte,hingegen vorwiegend als apikaler SCFA-/HCO3--Austauscher fungiert. Die bikarbonatunabhängige proteinvermittelte apikale Acetataufnahme scheint zum größten Teil elektroneutral zu erfolgen. Als Protein könnte eine MCT-Isoform daran beteiligt sein. Ein geringer Anteil der transepithelialen bikarbonatunabhängigen Acetatresorption scheint elektrogen zu erfolgen. Hier wäre sowohl die Beteiligung einer Anionenleitfähigkeit (z.B. der CFTR) als auch die Beteiligung eines elektrogenen Carriers (z.B. der SMCT1) denkbar.
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Wang, Ee Jen Wilson. "The effects of infection-related factors on bone resorption." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365291.
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Molyneaux, Glenn Arthur. "Resorption cycle heat pump with ammonia-water working fluid." Thesis, University of Ulster, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326335.
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Spence, Gavin Malcolm. "Carbonate substituted hydroxyapatite : is resorption responsible for enhanced bioactivity?" Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612051.
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Cohen-Solal, Martine. "Cytokines monocytaires et resorption au cours des pertes osseuses." Paris 5, 1994. http://www.theses.fr/1994PA05S008.
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La perte osseuse qui caracterise l'osteoporose est un facteur determinant de la fragilite osseuse. L'hyperresorption contribue a la perte osseuse par l'augmentation du nombre et de l'activite des osteoclastes. Des etudes experimentales suggerent que les cytokines jouent un role dans la regulation locale de la differenciation osteoclastique. Le but de ce travail est de preciser le role des cytokines de la resorption dans diverses situations cliniques. Grace a une nouvelle methode histomorphometrique, nous avons montre que la resorption osseuse est un phenomene majeur de la perte osseuse de patientes osteoporotiques, et que le nombre de cellules osteoclastiques est lie a l'importance de la resorption dans l'osteoporose commune. Afin d'en etudier les determinants, les modifications de production de cytokines par les monocytes circulants de femmes menopausees ont ete etudiees. L'activite de resorption osseuse in vitro de surnageant de culture de monocytes est augmentee chez des femmes menopausees, est liee a l'augmentation des taux d'il1, d'il6 et de tnf et peut etre inhibee par l'addition d'inhibiteurs. Chez des femmes plus agees non osteoporotiques, la production des 3 cytokines par des monocytes circulants en culture etait correlee a celle des monocytes medullaires prelevee au femur. Le nombre de cellules osteoclast-like (ocl) obtenu a la fin de culture des monocytes medullaires etait positivement correle au nombre d'osteoclastes presents sur les biopsies osseuses du col femoral, indiquant ainsi que la differenciation osteoclastique observee in vitro refletait l'activite osteoclastique in vivo. Enfin, nous avons etudie des patients atteints de syndrome d'hyper ige, syndrome rare d'immuno-deficience lors duquel survient des fractures. L'hyperresorption osseuse induite in vitro par les surnageants monocytaires est inhibee par l'indomethacine et s'associe a un defaut de production d'ifn.
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Martin, Joanne. "In vitro osteoclast resorption of calcium phosphate bone substitutes." Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.695663.
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Resorption of calcium phosphate (CaP) biomaterials is traditionally assessed using an osteoclast (QC) resorption assay where resorption pits formed on the CaP surface are analysed by microscopy techniques and quantified on the basis of pit number, pit area or pit volume. Pit area measurements (20) have become common practice when assessing CaP biomaterial resorption in vitro. Apart from the time consuming nature of pit area analysis techniques it is not a precise indicator of resorption; variations in pit depth are not taken into consideration and it is unsuitable for use on porous materials where visualisation of internal structures is difficult or for use on materials with rough surfaces where determination of individual pits would be difficult. A 3D quantification of bioresorption is available but requires specialised, expensive equipment. An appropriate measure of resorption was required to be more efficient and more cost-effective than the current available in vitro methods, but most importantly, to directly correlate with pit area measurements and have the ability to be used in a broad range of in vitro experiments. An QC resorption assay was developed and optimised through a series of experiments. The established assay was used to assess several outcome measures as potential indicators of resorption in vitro, namely; the correlation of percentage area resorbed in vitro with Ca and P concentration in cell culture medium, QC number and QC activity. A dense substrate free from surface anomalies was used to accurately correlate pit area with the alternative outcome measures. This body of work has established two main outcome measures of bioresorption in vitro that correlate with pit area measurements; Ca and P ion concentration in culture medium and QC specific enzyme activity. These outcome measures will prove invaluable for improving the fundamental understanding of QC resorption of CaP biomaterials.
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Miao, Dengshun. "Studies on the actions of bone anabolic drugs in vivo and in vitro." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300362.
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Hou, Peng. "Matrix metalloproteinases in the osteoclast, with special emphasis on the molecular cloning and the functional role of matrix metalloproteinase-12." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287350.
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Білоус, С. В., and П. М. Скрипніков. "Клініко-рентгенологічне обґрунтування вибору методу лікування внутрішньокореневої резорбції." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/11938.
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Krisp, Andreas. "Zur Resorption von Naringin aus Grapefruitsaft bei Mensch und Tier." [S.l.] : [s.n.], 2000. http://archiv.ub.uni-marburg.de/diss/z2001/0027.
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Nakamura, Chié. "Steuerung der kutanen Glucocorticoid-Resorption Einfluss von festen Lipid-Nanopartikeln /." [S.l.] : [s.n.], 2005. http://www.diss.fu-berlin.de/2005/87/index.html.
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Baron-Aguilar, Claudia Catalina. "Influence of Temperature on Yolk Resorption by Centropomus undecimalis Larvae." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/2997.
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In an effort to determine the optimal temperature for rearing Centropomus undecimalis larvae during the yolk resorption period, larval development was measured under four different temperature regimes (23, 25, 28 and 31 °C). The eggs were incubated at 28 °C until hatching, which occurred at about 17 hours post-fertilization. After hatching, temperatures were adjusted to the respective treatment levels. Measurements were collected from 25 individual larvae across rearing temperatures at the following pre-determined time intervals: at hatching, 24 hours post hatch (hph), 48 hph, and 72 hph. Morphometric measurements were obtained from photomicrographs, including yolk sac length and height, oil globule diameter, standard length, body height at anal pore, and eye diameter. Larvae in the 25 °C treatment had longer median standard length, body height, and more energy reserves than those larvae reared at other temperatures. The yolk sac and oil-globule were present up to 72 hph at 23 and 25°C, while these were entirely consumed after 48 hph in treatments at 28 and 31 °C. Centropomus undecimalis larvae had the highest growth rates during the first 24 hph, and this period corresponded to the highest energy consumption as determined by the decrease in yolk-sac and oil-globule volume. Survival was assessed during the third trial only. The 31 °C treatment presented the worst survival percentages, with a maximum survival of 37.2% at 24 hph, and 100% mortality at 72 hph. The 25 °C treatment featured higher survival at the end of the trial than the other treatments with 1.7% survival. Eye diameter didn't vary significantly with time and was not a useful parameter for tracking development during yolk resorption. These results led to the conclusion that 25 °C was the optimal temperature to raise snook larvae during the yolk-resorption period.
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Al-Dehaimi, Abdulwahed. "Evaluation of galactosyl hydroxylysine as a marker of bone resorption." Thesis, University of Sheffield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364314.
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Last, Keith Sydney. "Glycosaminoglycans in gingival crevicular fluid in relation to bone resorption." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317010.
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Brisseau, Kathrin. "Einfluss einer Protonenpumpenhemmung auf die Resorption von oral verabreichten Schilddrüsenhormonpräparaten." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-64934.
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Weltman, Belinda Jessica. "Root resorption associated with orthodontic tooth movement a systematic review /." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1236022079.
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Nicolai, Thomas [Verfasser]. "Kontrollierte verblindete Studie zur Ermittlung der dermalen Propan-1-ol- und Propan-2-ol-Resorption unter Ausschluss der pulmonalen Resorption während der chirurgischen Händedesinfektion / Thomas Nicolai." Greifswald : Universitätsbibliothek Greifswald, 2015. http://d-nb.info/1075777038/34.
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Herráiz, Yebes Alba. "Molecular analysis of ovarian resorption by hydric stress in Blatella germanica." Doctoral thesis, Universitat Pompeu Fabra, 2014. http://hdl.handle.net/10803/299212.
Full textAbstract:
In the present thesis we studied the effects of hydric stress in the ovary of the cockroach Blattella germanica. At morphological level, we described ovarian resorption induced by water deprivation. At a molecular level, we looked for markers differentially expressed under hydric stress. First, we focused on aquaporins given their role as water channel proteins. We cloned, sequenced and functionally characterised an aquaporin that transports water and urea. Then, we obtained a library of microRNAs (small non-coding RNAs that regulate gene expression post transcriptionally) present in the ovary under stress conditions. We analysed the differential expression of 13 of them and we observed that the majority were overexpressed under hydric stress. We selected miR-34-5p to perform a deeper study, including a study of their potential target mRNAs. Among the possible targets, we studied the function of Windei, a factor that resulted necessary for the trimethylation of lysine 9 in histone H3 and for chorion formation. Finally, we selected CARMER (an arginine methyltransferase) as hydric stress marker candidate. We assessed that it is overexpressed in response to hydric stress and that it is necessary for the dimethylation of arginine 17 in histone H3.En esta tesis estudiamos los efectos del estrés hídrico en el ovario de la cucaracha Blattella germanica. A nivel morfológico describimos el proceso de reabsorción ovárica tras la privación de agua. A nivel molecular buscamos marcadores diferencialmente expresados en respuesta a este estrés. Primero nos centramos en las acuaporinas por su papel como proteínas que forman un canal transportador de agua. Clonamos, secuenciamos y caracterizamos funcionalmente una acuaporina que transporta agua y urea. Después obtuvimos una biblioteca de microRNAs (RNAs cortos no codificantes que regulan la expresión génica post-transcripcionalmente) presentes en el ovario en situación de estrés. Analizamos la expresión diferencial de 13 de ellos y observamos que la mayoría se sobreexpresaban en situación de estrés. Elegimos miR-34-5p para hacer un estudio más profundo, incluyendo un análisis de sus potenciales mRNA diana. De entre ellos, estudiamos la función de Windei y comprobamos que dicho factor es necesario para la trimetilación de la lisina 9 en la histona H3 y para la formación del corion. Por último, seleccionamos CARMER (una arginina methyltransferasa) como candidato a marcador de estrés hídrico. Comprobamos que CARMER se sobreexpresa en respuesta a estrés y que es necesario para la dimetilación de la arginina 17 en la histona H3.
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Greulich, Markus. "Einfluss von Tensiden auf die Resorption von Substraten der ABC-Transportproteine." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969716591.
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Lambrecht, Kirstin. "Einfluß der Wirkstoffformulierung auf die Resorption von Vitamin A beim Ferkel." Diss., lmu, 2006. http://nbn-resolving.de/urn:nbn:de:bvb:19-50786.
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Nagao, Jiro. "Computer-Aided Diagnosis of Alveolar Bone Resorption using Dental 3DCT Images." INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2005. http://hdl.handle.net/2237/10393.
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Mrochen, Nina [Verfasser]. "Untersuchungen zur Regulation der jejunalen Calcium-Resorption beim Schaf / Nina Mrochen." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2010. http://d-nb.info/1009624393/34.
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Mansfield, Ian David. "The synthesis of novel agents which inhibit tumour-stimulated bone resorption." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/27412.
Full textAbstract:
A range of conjugates which focused on bisphosphonates as delivery molecules and on oestrogens as resorption inhibitors were synthesised. Various moieties were coupled through an ester linkage to bisphosphonates which were then converted to the corresponding bisphosphonic acids. This ester linkage was considered to be readily hydrolysable under normal physiological conditions.
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Herráiz, Yebes Alba 1984. "Molecular analysis of ovarian resorption by hydric stress in Blatella germanica." Doctoral thesis, Universitat Pompeu Fabra, 2014. http://hdl.handle.net/10803/299212.
Full textAbstract:
In the present thesis we studied the effects of hydric stress in the ovary of the cockroach Blattella germanica. At morphological level, we described ovarian resorption induced by water deprivation. At a molecular level, we looked for markers differentially expressed under hydric stress. First, we focused on aquaporins given their role as water channel proteins. We cloned, sequenced and functionally characterised an aquaporin that transports water and urea. Then, we obtained a library of microRNAs (small non-coding RNAs that regulate gene expression post transcriptionally) present in the ovary under stress conditions. We analysed the differential expression of 13 of them and we observed that the majority were overexpressed under hydric stress. We selected miR-34-5p to perform a deeper study, including a study of their potential target mRNAs. Among the possible targets, we studied the function of Windei, a factor that resulted necessary for the trimethylation of lysine 9 in histone H3 and for chorion formation. Finally, we selected CARMER (an arginine methyltransferase) as hydric stress marker candidate. We assessed that it is overexpressed in response to hydric stress and that it is necessary for the dimethylation of arginine 17 in histone H3.En esta tesis estudiamos los efectos del estrés hídrico en el ovario de la cucaracha Blattella germanica. A nivel morfológico describimos el proceso de reabsorción ovárica tras la privación de agua. A nivel molecular buscamos marcadores diferencialmente expresados en respuesta a este estrés. Primero nos centramos en las acuaporinas por su papel como proteínas que forman un canal transportador de agua. Clonamos, secuenciamos y caracterizamos funcionalmente una acuaporina que transporta agua y urea. Después obtuvimos una biblioteca de microRNAs (RNAs cortos no codificantes que regulan la expresión génica post-transcripcionalmente) presentes en el ovario en situación de estrés. Analizamos la expresión diferencial de 13 de ellos y observamos que la mayoría se sobreexpresaban en situación de estrés. Elegimos miR-34-5p para hacer un estudio más profundo, incluyendo un análisis de sus potenciales mRNA diana. De entre ellos, estudiamos la función de Windei y comprobamos que dicho factor es necesario para la trimetilación de la lisina 9 en la histona H3 y para la formación del corion. Por último, seleccionamos CARMER (una arginina methyltransferasa) como candidato a marcador de estrés hídrico. Comprobamos que CARMER se sobreexpresa en respuesta a estrés y que es necesario para la dimetilación de la arginina 17 en la histona H3.
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Morgan, Hayley Michaela. "Mechanisms involved in breast tumour cell mediated bone resorption in vitro." Thesis, King's College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393664.
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Maschmann, Ira. "Untersuchung der perkutanen Resorption von Benzoesäure an der isoliert hämoperfundierten Schweineextremität /." Berlin : Mbv, 2008. http://d-nb.info/992998131/04.
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Ngan, Daniel C. S. "The genetic contribution to orthodontic root resorption : a retrospective twin study." Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/4781.
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Jimenez, Vanessa. "Analysis of root resorption after light and heavy extrusive orthodontic forces." Thesis, Faculty of Dentistry, 2010. http://hdl.handle.net/2123/7075.
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Selinger, Christina Imanta. "Identification of RANKL-Regulated Genes Involved in Osteoclast Differentiation and Resorption." Thesis, Griffith University, 2008. http://hdl.handle.net/10072/367396.
Full textAbstract:
Peripheral blood mononuclear cells (PBMCs) are pluripotent for osteoclast and macrophage cell lineages. The differentiation of macrophages and osteoclasts from a common monocyte precursor is induced following exposure to macrophage-colony stimulating factor (M-CSF), or both M-CSF and receptor activator of nuclear factor B ligand (RANKL) respectively. Differential gene expression resulting from cytokine treatment of PBMCs was examined over time using differential display PCR (DD-PCR) and quantitative real-time PCR (Q-PCR). Q-PCR analysis verified the expression of a new chemokine, FAM19A1, in addition to Special AT-rich binding sequence 1 (SATB1), solute carrier family 16 member 6 (SLC16A6) and LIM kinase 1 (LIMK1) in primary human osteoclasts, however, only LIMK1 was significantly up-regulated by RANKL.
Highly efficient delivery of small interfering RNA (siRNA) transfection to primary human osteoclasts was developed, and represents a technical milestone due to the inherent phagocytic tendencies of the PBMC lineage. The development of RNA interference for use in primary human osteoclasts was conducted using siRNA synthesised by Dicer enzyme, to verify the role of candidate genes in osteoclast differentiation and osteoclast bone resorption. Cathepsin K (CTSK) is the key proteinase expressed by osteoclasts, and was used as a benchmark for the optimisation of siRNA inhibition in primary human osteoclasts. Transfection of primary human osteoclasts with siRNA to CTSK significantly diminished bone resorption, with a 60% reduction in area resorbed (P=1.3x10-2), and a 50% reduction in pit number (P=1.8x10-2). Normal bone remodelling is dependent on both the rate of osteoclast formation and resorption. A number of genes were examined for their contribution to osteoclast formation and resorption using siRNA. Nuclear factor of activated T cells, calcineurin dependant 1 (NFATc1) inhibition was found to significantly deplete osteoclast formation (P=4.0x10-3), confirming other NFATc1 inhibition studies, and the necessity of NFATc1 in osteoclast differentiation. In pre-differentiated osteoclasts, siRNA targeting NFATc1 did not reduce osteoclast bone resorption, rather it significantly increased area resorbed (P=1.0x10-3), with no significant difference in cell number. This result suggests that NFATc1 may act in accordance with its regulator calcineurin, which has been found to enhance osteoclast differentiation, but inhibit osteoclast resorption in mature cells.
The inhibition of LIMK1 by targeted small interferring RNA (siRNA) was found to significantly diminish osteoclast formation (P=1.0x10-3), pits resorbed (P=4.2x10-2), as well as area resorbed (P=4.0x10-3). LIMK1 is a signalling kinase, identified as RANKL-regulated in murine osteoclasts, notwithstanding, this is the first study that confirms LIMK1 involvement in osteoclast formation and activity. LIMK1/cofilin-mediated actin reorganisation is critical to progenitor cell migration to stromal cells, and also regulates the stability of F-actin formation. F-actin rings were analysed in LIMK1 depleted pre-differentiated osteoclasts, which seemed to have formed properly and did not appear dissimilar from controls.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
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Krajinovic, Stipe [Verfasser]. "Biokompatibilität und Resorption eines neuen Calciumphosphatzementes im osteoporotischen Schafsmodell / Stipe Krajinovic." Ulm : Universität Ulm. Medizinische Fakultät, 2005. http://d-nb.info/1015471498/34.
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Ren, Zhongyuan. "Small molecules regulated bone resorption and enzyme activity in osseous cells." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10291/document.
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La Cathepsine K est parmi la plus efficace des collagénases de mammifère pour cliver la triple hélice de collagène de type-1. Nous avons développé une série d'azanitriles, (CKI-8 and CKI-13) inhibiteurs de cathepsine K. CKI-8 (un isomère de CKI-13) et CKI-13 ne sont pas toxiques sur les osteoblastes Saos-2 et les cellules RAW 264.7 jusqu' à une concentration de 1000 nM, tandis qu'ils ne le sont pas jusqu'à une concentration de 100 nM sur les osteoclastes. CKI-8 n'affecte pas l'activité de la phosphatase alkaline ainsi que la minéralisation induite par les Saos-2 et par les osteoblastes primaires. CKI-13 diminue de 35 % la minéralisation induite par les Saos-2 tandis qu'il n'affecte pas la minéralisation induite par les osteoblastes primaires. L'addition de CKI-13 diminue l'activité de la phosphatase alkaline d'environ 20% (Saos-2) et de 40 % (osteoblastes primaires). La résorption osseuse sur des tranches d'os d'origine bovine est diminuée avec 10 nM de CKI-13, 100 nM de CKI- 8 et 100 nM d'inhibiteur commercial E64. CKI-8 et CKI-13 diminuent la mobilité des osteoclastes. Nous avons développé un dosage d'hydrolyse de PPi par la phosphatase alkaline au moyen de l'IR, ayant l'avantage de fonctionner sur des vésicules matricielles et des cellules avec des substrats naturels à un pH physiologique. La bande de PPi localisée à 1107 cm-1 (∑= 2158 ± 211 M-1.cm-1) et celles de Pi localisées à 1076 cm-1 (∑= 1346 ± 116 M-1.cm- 1) et à 991 cm-1 (∑= 493 ± 49 M-1.cm-1) ont servis à mesurer les concentrations du substrat et du produitCathepsin K is among the most potent mammalian collagenase, capable of cleaving the triple helix in type-I collagen. We developed a series of azanitriles (CKI-8 and CKI-13) which are inhibitors of cathepsin K. CKI-8 (an isomer of CKI-13) and CKI-13 did not induce significant toxicity on osteoblasts Saos-2 and RAW 264.7 cells up to 1000 nM, while they were not toxic on mature osteoclasts up to 100 nM. Commercial E64 inhibitor was not toxic in primary osteoclast cells up to 1000 nM. CKI-8 did not affect alkaline phosphatase activity as well the mineralization induced by Saos-2 cells and by primary osteoblasts. CKI-13 decreased by 35% the mineralization induced by Saos-2 cells while it did not on mineralization induced by primary osteoblasts. Addition of CKI-13 decreased alkaline phosphatase activity by around 20% (Saos-2 cells) and 45% (primary osteoblasts). Bone resorption on bovine slices decreased significantly with 10 nM of CKI-13, with 100 nM of CKI-8 and commercial inhibitor E64. Our findings indicated that CKI-8 and CKI-13 inhibited bone resorption and affected the mobility of osteoclast. To monitor directly the PPi hydrolytic activity by alkaline phosphatase, we developed an infrared (IR) assay taking the advantage to use natural substrate under physiological pH in matrix vesicles and in living cells. PPi band located at 1107 cm-1 (∑= 2158 ± 211 M-1.cm-1) and Pi bands located at 1076 cm-1 (∑= 1346 ± 116 M-1.cm-1) and at 991 cm-1 (∑= 493 ± 49 M-1.cm-1) served to measure the substrate and the product concentrations
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McManus, Stephen. "Modulation of tumor necrosis factor related apoptosis-inducing ligand (trail) receptors in a human osteoclast model in vitro." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/4077.
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We have previously shown that osteoclasts (OCLs) from multiple myeloma (MM) specimens vary from healthy OCLs in their expression of the TRAIL receptors. TRAIL (TNF-Related Apoptosis-Inducing Ligand), a member of the TNF superfamily, has been shown to induce apoptosis in cells by binding receptors DR4 and DR5, but not DcR1 and DcR2, its decoy receptors, which lack the necessary internal death domain. The observed modulation of these receptors may confer a resistance to apoptosis in the MM environment, and could be related to the cytokine pattern that primarily involves the resorption promoting Receptor Activator of NF-[kappa]B Ligand (RANKL) and Macrophage Inflammatory Protein 1 (MIP-1[alpha]). The aim of our study was to determine which cytokines present in the disease might be responsible for this modulation. In long term cultures of OCL precursors from cord blood in the presence of M-CSF and RANKL, multinucleated cells (MNCs) that express OCL markers form, and can resorb bone. Through immunocytochemistry we showed that these MNCs can express all four TRAIL receptors. By stimulating with various cytokines (RANKL, MIP-1[alpha], Transforming Factor [bêta] (TGF[bêta]), osteoprotegerin (OPG), TRAIL), and parathyroid hormone (PTH) in OCL cultures, we were able to observe receptor modulation at the mRNA level using real time PCR, the protein level using Western blot analysis, and cell surface expression via immunocytochemistry. To determine if these changes translated to a difference in resistance to apoptosis, cells treated with [with] apoptosis-inducing levels of TRAIL after 5 days of stimulation with the selected cytokines were evaluated via TUNEL to quantify apoptosis. While no correlation has yet been established between the observed receptor modification and apoptosis induction, sample size is a factor, and further tests will be performed. Our results suggest the possibility that TRAIL receptor modification is induced by multiple cytokines present in bone diseases, capable of altering both the susceptibility and resistance pathways in osteoclasts. By potentially prolonging the lifespan of the OCL, these regulatory influences may ultimately be contributory factors to the augmentation of resorption in the micro-environment of bone resorptive diseases like multiple myeloma, Paget's disease of bone, or osteoporosis.