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The anatomical relationship and variation between internal jugular veins and carotid arteries in uraemic patientsLo, Man-wai., 盧文偉. January 2011 (has links)
published_or_final_version / Anatomy / Master / Master of Medical Sciences
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Endovascular Embolization for the Treatment of Right Carotid-Jugular Arteriovenous Fistula, With Communicating Left Vertebral-Right Jugular Arteriovenous FistulaMentzer, Caleb j., Yon, James r., Beatty, John s., Holsten, Steven B. 01 January 2016 (has links)
Traumatic arteriovenous fistulas of the neck are a relatively uncommon injury, whose ramifications can include immediate or delayed neurological insults, massive bleeding, or death. Angiography and embolization have been increasingly used to manage this complex injury pattern. In this particular case, the patient underwent management of bilateral communicating arteriovenous fistulae using a commercially available plug occlusion device. Epidemiology, with an emphasis on patient management and outcomes, is discussed.
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Modelling of Venous Biomechanics and Evaluation using Imaging, Positive Airway Pressure and Postural ChangesHolmgren, Madelene January 2016 (has links)
Knowledge about biomechanical properties of veins is of importance for understanding the physiologyof the venous system. Specifically for this thesis there is a motivation based on an idea of how to usebiomechanics of the vein in the development of new non-invasive measurement techniques for assessingthe pressure in the brain. The cross sectional area of veins is known to depend on pressure changes insidethe vessel. There are many ways of provoking these pressure changes, like changing posture or creating apositive airway pressure. The hypothesis is that the positive airway pressure will increase the intrathoracic pressure and in turnincrease the pressure in the internal jugular veins by the same magnitude. The cross sectional area will from a pressure change subsequently change with respect to the biomechanical properties of the vessel walls. A first aim in this study was to determine how the cross sectional area of the internal jugular veins is altered due to changes in airway pressure. A second aim was to develop and evaluate a model where the biomechanical properties of the internal jugular veins is described, based on the relationship between pressure and area of the vein. Ultrasound measurements were performed on one healthy adult man to study the effect on the cross sectional area at different pressure provocations. Measurements on the subject was performed at four different head up tilt angles, causing a pressure decrease in the internal jugular vein. A controlled Valsalva method was performed to give the positive airway pressure giving corresponding pressure increases. With an increased airway pressure the effect on cross sectional area changes was about 23% of the effect dueto hydrostatic pressure changes, at a tilt angle from 0° to 8°. At a tilt angle from 8° to 16° the effect was about 35%. Thus the venous pressure seems to be increased due to an increased airway pressure, but not tothe same magnitude. The theoretical model was developed and subsequently evaluated using existing head down tilt magneticresonance imaging data on nine healthy volunteers. An expression for how radius of the vessel depends on pressure changes was derived and evaluated. This expression included individual biomechanical properties that were estimated on group level for the nine subjects. The resulting equation could beused to give an approximate prediction of the increase in radius to a change in venous pressure. In conclusion, the hypothesis suggesting that a positive airway pressure would give an equally increased venous pressure could not be confirmed, and this knowledge should be considered when trying to assess thepressure in the brain with this technique. The derived biomechanical model was promising for predictionof cross sectional area with respect to a change in venous pressure. / Att ha kännedom om biomekaniska egenskaper hos vener är viktigt för att kunna förstå fysiologin hos vensystemet. I den här rapporten finns det i synnerhet ett intresse av detta baserat på en idé för hur veners biomekanik kan användas för att utveckla en ny icke-invasiv mätteknik för att uppskatta trycket i hjärnan. Det är känt att tvärsnittsnittarean av vener beror på tryckförändringar inne i kärlet. Att provocera fram dessatryckförändringar går att göra på många sätt, till exempel genom en förändrad kroppsposition eller genomatt sätta ett positivt tryck på luftvägarna. Hypotesen är att ett positivt luftvägstryck kommer att höja det intratorakala trycket, vilket i sin turkommer att höja trycket inne i de interna jugularvenerna lika mycket. Tvärsnittsarean kommer därmed att ändras enligt biomekaniska egenkaper hos kärlväggen. Ett första syftet i det här arbetet var att bestämma hur tvärsnittsarean av de internal jugularvenerna varierar enligt förändringar i luftvägstryck. Det andra syftet var att utveckla en modell som beskriver de biomekaniska egenskaperna hos de interna jugularvenerna. Detta baserat på relationen mellan tryck och area hos venen. För att studera effekten på tvärsnittsarea för olika tryckprovokationer, genomfördes ultraljudsmätningar på en frisk och vuxen man. Mätningarna på subjektet genomfördes med överkroppen positionerad i fyra olika positiva vinklar relativt horisontalplanet, vilket leder till ett minskat tryck i jugularvenerna. En kontrollerad Valsalvametod användes för att skapa det positiva luftvägstrycket som då ska ge en motsvarande tryckökning. Vid en tiltvinkel på 8° var effekten på areaförändringarna som en följd av ökat luftvägstryck ca 23% av effekten som en följd av de hydrostatiska tryckförändringarna. Vid en tiltvinkel på 16° var effekten ca 35%. Det verkar som att ventrycket ökar med ökat luftvägstryck, men inte med samma storleksordning som det pålagda trycket. Den teoretiska modellen utvecklades och utvärderades sedemera med hjälp av befintligt MRI-data för nio friska och frivilliga subjekt, där överkropparna var positionerade i nedåt tilt. Modellen bestod av ettuttryck för hur radien av ett kärl beror på tryckförändringar inne i det. Modellen innehåller individspecifika egenskaper men utvärderingen gjordes på gruppnivå för de nio subjekten. Det resulterande uttrycket kunde användas för att ge en approximativ förutsägelse om hur radie förändras till följd av en variation i ventryck. Som slutsats så kunde hypotesen som föreslog att ett positivt luftvägstryck skulle ge en lika stor ökning av ventryck inte bekräftas. Om denna teknik ska användas för att försöka bestämma trycket i hjärna så måste hänsyn tas till dessa resultat. Den utvecklade biomekaniska modellen verkar lovande för att kunna förutsäga tvärsnittsarea utifrån ventrycksförändringar.
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Students using isolated uterine and other preparations show bimatoprost and prostanoid FP agonists have differently activated profilesMarshall, Kay M., Abbas, F., Senior, J., Woodward, D.F. January 2009 (has links)
No / The pharmacology of bimatoprost, a synthetic prostaglandin-amide, was examined in prostaglandin F2¿ (PGF2¿)-sensitive preparations. Bimatoprost potently contracted the rabbit isolated uterus (pEC50=7.92±0.16). In contrast, bimatoprost exhibited weak excitatory activity in human myometrium from pregnant and nonpregnant donors, mouse uterus, rat uterus, and endothelium-intact rabbit jugular veins, and did not stimulate DNA synthesis in mouse fibroblasts. The possibility that the effects of bimatoprost may reflect partial agonism at prostanoid FP receptors was examined and the contractile effects of full agonists, 17-phenyl PGF2¿ (FP) and U-46619 (TP, a control), were determined in the absence and presence of 1 ¿M bimatoprost on the mouse uterus. Analyses of the agonist¿agonist functional studies showed no antagonism, indicating that bimatoprost is not a partial agonist. Bioassay metabolism studies of bimatoprost and latanoprost (FP receptor agonist prodrug) in the rabbit uterus were conducted using recipient mouse uterus. Results indicated that the potent responses to bimatoprost in the rabbit uterus are produced by the intact molecule and not by its putative free acid metabolite, 17-phenyl PGF2¿. Some hydrolysis of latanoprost to latanoprost free acid appears to have occurred in the rabbit uterus, according to biological detection.
The pharmacology of bimatoprost could not be explained by its interaction with known prostanoid FP receptors and was independent of species-, tissue-, or preparation-related factors. The potent contractile effects of bimatoprost in the rabbit uterus provide further pharmacological evidence for the presence of a novel receptor population that preferentially recognises bimatoprost.
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