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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Nature and Origin of Fissure Ore at the Porphyry-Epithermal Transition Zone of the Bingham Canyon Porphyry Cu-Au-Mo Deposit, Utah

Tomlinson, David Harris 01 July 2019 (has links)
Late-stage fissure-filling ore at the world class Bingham Canyon, Utah, porphyry copper deposit has long been recognized, but poorly studied. Physical and chemical characterization of the Pb-Zn-Cu-Ag-Au mineralized fissures in the porphyry-epithermal transition zone provides insight into the origin, timing, and controls of ore deposition. These sheared sulfide-rich fissures are dominated by pyrite and multiple generations of quartz, with lesser amounts of other sulfides and gangue minerals. Au (0.27 to 4.61 ppm) provides the most value to the ore in the transition zone. Host rocks include Eocene monzonite and Paleozoic limestone and quartzite"”all of which can contain economic ore bodies. Associated alteration is predominantly sericitic and argillic. Mineralization into the wall rocks is restricted, not exceeding 1.5 m from the fissure margins. Mineral assemblages vary with distance from the center of the main Cu-Mo deposit and the modal abundances are dependent on host rock. The appearance of both galena and sphalerite (and tennantite to an extent) mark the transition from a porphyry to an epithermal environment. This is accompanied by an increased concentration of chalcophile trace elements in sulfides as determined by EMPA and LA-ICP-MS. Significant hosts of Ag include galena and tennantite, while Cu is hosted primarily in chalcopyrite, tennantite, and sphalerite. Gold does not appear to be hosted in solid solution, but may be focused along fractures or inclusions in pyrite. δ3434S values of fissure pyrite has a narrow range (+2.3 to 3.4‰), while δ18O of quartz is more variable and high (+11.5 to 14.0‰) relative to typical hydrothermal quartz. This can be explained by increased fractionation at lower temperatures in the magmatic fluids, which could have additionally mixed with exchanged 18O-rich meteoric water. Ore grades improve with distance from the center of the deposit; however, this is accompanied by higher concentrations of elements (Pb, As, Bi, etc.) undesirable for downstream processing. The mineralized fissures were created sequentially throughout the formation of the deposit. Initial joints probably formed as a result of the intrusion of a barren equigranular monzonite. The NE orientation of the joints was controlled by the regional stress field, which is more apparent distal to the center of the deposit. A quartz monzonite porphyry then intruded, dilating the joints to allow precipitation of quartz and then pyrite during the Cu-Au-stage of mineralization in the main ore body. After dike-like intrusions of latite porphyry and quartz latite porphyry intruded, galena, sphalerite, and pyrite precipitated to form the Pb-Zn-Ag mineralization. This was followed by late precipitation of chalcopyrite and tennantite (and likely Au mineralization).
192

Left Atrial Pressure as a Predictor of Success in Catheter Ablation of Atrial Fibrillation in a Real-Life Cohort

Manfrin, Massimiliano, Mugnai, Giacomo, Rauhe, Werner, Velagic, Vedran, Unterhuber, Matthias 04 May 2023 (has links)
Aims: The clinical role of the left atrial (LA) hypertension in patients with atrial fibrillation (AF) and its role as predictor in those undergoing pulmonary vein (PV) isolation is still unknown. The aim of the present study was to analyze the role of LA pressure in patients with nonvalvular AF who underwent PV isolation and its implication for AF catheter ablation. Methods: Consecutive patients with drug resistant AF who underwent PV isolation at San Maurizio Regional Hospital of Bolzano (Italy) as index procedure were included in this analysis. Results: A total of 132 consecutive patients (97 males, 73%; mean age 58.0 ± 13.2 years) were included in the analysis. Eleven patients (8%) underwent radiofrequency ablation and 121 (92%) cryoballoon ablation. Higher LA pressures were found in 54 patients (40.9%). At a mean follow up of 14.3 ± 8.2 months (median 12 months), the success rate without antiarrhythmic therapy was 65.9% (87/132; considering the blanking period). Female gender and continuous mean LA pressure were significantly associated with AF recurrence and remained significant on multivariable Cox analysis (respectively, HR 1.845, 1.00–3.40, p = 0.05 and HR 1.066, 1.002–1.134, p = 0.04). We identified a LA mean pressure of >15 mmHg as ideal cutoff and constructed a model to predict AF recurrence which fitted with a concordance index (C-index) of 0.65 (95% CI 0.56–0.75), logrank score p = 0.003.
193

Functional Requirement and Redundancy of Egfr Ligands in Drosophila Development

Austin, Christina L. January 2013 (has links)
No description available.
194

Isolation and detection of bean yellow mosaic, clover yellow vein and peanut stunt viruses from Trifolium L. species

Srinivasan, Indira 12 September 2009 (has links)
Trifolium L. (clover) are annual or perennial species established in pasturelands to improve forage productivity and quality. In the southeastern United States, Trifolium repens L. (white clover) and Trifolium pratense L. (red clover) are important species, susceptible to virus infection. Objectives of this research were to isolate bean yellow mosaic (BYMV), clover yellow vein (CYVV) and peanut stunt (PSV) viruses from naturally infected white and red clovers from different locations in Virginia; and, to compare Indirect Enzyme-Linked ImmunoSorbent Assay (i-ELISA) and tissue immunoblot assay (TIBA) as methods for virus detection. A total of five white clover samples from Augusta, Richmond and Washington Counties were positive against CYVV antiserum and four white clover samples from Augusta County were positive against PSV antiserum. Single red clover samples from Frederick and Montgomery Counties were positive against BYMV antiserum. There were notable differences in host range with samples that tested positive for CYVV and BYMV, indicating they may be different strains. PSV was evenly distributed in the plant, whereas CYVV was higher in older plant parts. Viruses were successfully detected by blotting leaf samples directly onto membranes, thereby simplifying the sample preparation step. A number of membranes, such as nitrocellulose, nylon, chromatography paper, filter paper and writing pad could be used to detect viruses. In terms of specificity, immunoblots were equal or superior to i-ELISA. The TIBA should be useful in support of breeding and plant pathology studies as it is simple and rapid, and is less laborious and less expensive than i-ELISA. / Master of Science
195

Endothelial Cell-Specific Knockout of Meis1 Protects Ischemic Hindlimb Through Vascular Remodeling

Chen, Miao 28 June 2018 (has links)
Peripheral artery disease (PAD) affects more than 200 million people worldwide. PAD refers to illness due to a reduction or complete occlusion of blood flow in the artery, especially to the extremities in disease conditions, such as atherosclerosis or diabetes. Critical limb ischemia (CLI) is a severe form of PAD associated with high morbidity and mortality. Currently, no effective and permanent treatments are available for this disease. The current endovascular medications (e.g., angioplasty or stents) only relieve the clinical symptoms while the surgical therapies (e.g., bypass or endarterectomy) require grafting vessels from a healthy organ to the diseased limb of the patient. However, even with these therapeutic techniques, 30% of patients still undergo limb amputation within a year. Thus, understanding of disease mechanism and development of new therapeutic approaches are in urgent needs. Meis1 (myeloid ecotropic viral integration site 1) gene belongs to the three-amino-acid loop extension subclass of homeobox gene families, and it is a highly conserved transcription factor in all eukaryotes. Up to date, little is known about the role of Meis1 in regulating vascular remodeling under ischemic condition. In this study, we aim to investigate the role and underlying mechanism of Meis1 in the regulation of arteriogenesis and angiogenesis using hindlimb ischemia model of transgenic neonatal mice. The long-term goal is to develop a new treatment for patients with PAD. Three separate but related studies were planned to complete the proposed research aims. To better understand the role of Meis1, we reviewed, in the first chapter, all literature relevant to the recent advances of the Meis1 in normal hematopoiesis, vasculogenesis, and heart developments, which were mostly studied in zebrafish and mouse. Briefly, Meis1 is found to be highly expressed in the brain and retina in zebrafish and additional in the heart, nose, and limb in mouse during the very early developmental stage, and remains at a low level quickly after birth. Meis1 is necessary for both primitive and definitive hematopoiesis and required for posterior erythroid differentiation. The absence of Meis1 results in a severe reduction of the number of mature erythrocytes and weakens the heart beats in zebrafish. Meis1 deficiency mouse is dead as early as E11.5 due to the severe internal hemorrhage. In addition, Meis1 is essential in heart development. Knock-down of Meis1 can promote angiotensin II-induced cardiomyocytes (CMs) hypertrophy or CMs proliferation, which can be repressed by a transcription factor Tbx20. Meis1 appears to play a complicated role in the blood vessels. Although the major blood vessels are still normal when global deletion of Meis1, the intersegmental vessel cannot be formed in Meis1 morphants in the zebrafish, and the small vessels are either too narrow or form larger sinuses in Meis1 deficient mouse. The effects of Meis1 on the vascular network under normal and disease (ischemia) condition remain largely unknown, and the existing data in this field is limited. In the second chapter, we developed a method protocol to identify mice of all ages, especially neonates that we faced methodological difficulties to easily and permanently label prior to our major experiments. In this study, single- or 2-color tattooing (ear, tail, or toe or combinations) was performed to identify a defined or unlimited number of mice, respectively. Tail tattooing using both green and red pastes was suitable for identifying white-haired neonatal mice as early as postnatal day (PND) 1, whereas toe tattooing with green paste was an effective alternative approach for labeling black-haired mouse pups. In comparison, single-color (green) or 2-color (green and red) ear tattooing identified both white and black adult mice older than three weeks. Ear tattooing can be adapted to labeling an unlimited number of adult mice by adding the cage number. Thus, tattooing various combinations of the ears, tail, and toes provides an easy and permanent approach for identifying mice of all ages with minimal disturbance to the animals, which shows a new approach than any existing method to identify mouse at all ages, especially the neonatal pups used in the present study (Chapter 4). Various formation of hindlimb ischemia with ligations of femoral artery or vein or both have been reported in the literature. The ischemic severity varies dependent on mouse strains and ligation methods. Due to the tiny body size of our experimental neonatal mice (PND2), it is technically challenging to separate the femoral artery from femoral vein without potential bleeding. In the third chapter, we aimed to explore a suitable surgical approach that can apply to neonatal mice. To this end, we compared the effects of femoral artery/vein (FAV) excision vs. femoral artery (FA) excision on hindlimb model using adult CD-1 mice. We showed during the 4-week period of blood reperfusion, no statistically significant differences were found between FAV and FA excision-induced ischemia regarding the reduction of limb blood flow, paw size, number of necrotic toes, or skeletal muscle cell size. We conclude that FAV and FA excision in CD-1 mice generate a comparable severity of hindlimb ischemia. In other words, FAV ligation is no more severe than FA ligation. These findings provide valuable information for researchers when selecting ligation methods for their neonate hindlimb models. Based on these findings, we selected FAV ligation of hindlimb ischemia approach to study the function of Meis1 in vascular remodeling of neonatal mice. In the fourth chapter (the main part of my dissertation), we investigated the roles of Meis1 in regulating arteriogenesis and angiogenesis of neonatal mouse under the ischemic condition. To this end, endothelial cell-specific deletion of Meis1 was generated by cross-breeding Meis1flox/flox mice with Tie2-Cre mice. Wild-type (WT, Meis1f/f) and endothelial cell-specific knock-out (KO, Meis1ec-/-Tie2-Cre+) C57BL/6 mice at the age of PND2 were used. Under the anesthesia, the pups were subject to hindlimb ischemia by excising FAV. Laser Doppler Imager was used to measure the blood flow pre- and post-surgery up to 28 days. Toe necrosis, skeletal regeneration, and vascular distributions were examined at the end of experiments (PND28 post-ischemia). Surprisingly, during 4-week periods after ischemia, the blood flow ratios (ischemic vs. control limb) in KO mice significantly increased compared to WT on PND14 and PND28, suggesting the inhibitory effects of Meis1 on blood flow recovery under ischemic condition. Meanwhile, WT mice showed more severe necrotic limb (lower ratio of limb length and area, and higher necrotic scores at PND7) than those in the KO mice. Furthermore, significant increases in diameters of Dil-stained arterioles of the skin vessel and the vessels on the ligation site were observed in KO mice, indicating the enhanced arteriogenesis in KO mice. To investigate the underlying mechanism, RNA from the ischemia and control limb was extracted and q-PCR was used to study the potential genes involved in the mechanism. Casp3 and Casp8 were found downregulated showing less apoptosis in the KO mice. On the other hand, endothelial cells (ECs) were isolated from the lungs of 3-5 WT and KO neonates using CD31 Microbeads. CD31+ cells were plated and treated with 0, 0.5, and 1μM doxorubicin for 24 hours and analyzed with various assays. Meis1-KO ECs demonstrated higher cell viability and formed a higher number of vascular tubes than those in WT ECs following 0.5μM Dox treatment, presenting the potential ability of angiogenesis in KO-ECs. Furthermore, the increased viability in KO ECs may be due to the decreased expression or activities of Casp8 and Casp3. In conclusion, my present studies have developed a new methodology to easily and permanently identify all mice at any ages. The insignificant differences between FAV and FA ligations suggest that a relative-easy surgical approach could be used to generate hindlimb ischemic model, which potentially reduces the cost, decreases the surgical time and prevents damage of femoral nerve from surgical tools. More importantly, by using transgenic mice, we found that Meis1-KO dramatically increased blood flow and protected the ischemic hindlimb through vascular remodeling. Obviously, the molecular and cellular mechanisms underlying the above beneficial effects appear complicated and likely to involve multiple cellular remodeling processes and molecular signaling pathways to enhance arteriogenesis and angiogenesis and/or reduce cellular apoptosis through Meis1-mediated pathways. Our study demonstrated that under ischemic condition, knockout of Meis1 increases expression of Hif1a, which then activates Agt or VEGF, thus enhances arteriogenesis or angiogenesis; In addition, knockout of Meis1 activates Ccnd1, which subsequently promotes regeneration of skeletal muscle, and reduces expression of Casp8 and Casp3, thus preventing limb tissue from ischemia-induced apoptosis. Our innovative findings offer great potential to ultimately lead to new drug discovery or therapeutic approaches for prevention or treatment of PAD. / PHD
196

Students using isolated uterine and other preparations show bimatoprost and prostanoid FP agonists have differently activated profiles

Marshall, 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.
197

Prospektive Evaluation kardiovaskulärer Risikofaktoren bei Patienten mit venösen Gefäßverschlüssen im Auge / Prospective evaluation of cardiovascular risk factors in patients with retinal vein occlusions

Best, Janina Monika 16 February 2016 (has links)
Retinale Venenverschlüsse sind eine der häufigsten vaskulären Netzhauterkrankungen. Bei der Entstehung und dem Verlauf von venösen Gefäßverschlüssen im Auge spielen kardiovaskuläre Risikofaktoren eine entscheidende Rolle. Patienten mit einem retinalen Venenverschluss weisen vermehrt vaskuläre Risikofaktoren für arterielle Gefäßkrankheiten auf, weswegen es von hoher klinischer Relevanz ist, diese frühzeitig zu erkennen und zu behandeln. Bisher gibt es kein einheitliches Untersuchungsschema zur Ursachenabklärung eines retinalen Venenverschlusses. Ziel ist es, Empfehlungen einer zukünftigen Routinediagnostik für venöse Gefäßverschlüsse im Auge auszusprechen. In der FIND-AF-EYE-Studie wurde erstmals durch eine umfangreiche Diagnostik an insgesamt 101 Patienten mit retinalen Gefäßverschlüssen eine systematische Abklärung kardiovaskulärer Risikofaktoren kontrolliert durchgeführt. Die Diagnostik umfasste eine duplexsonographische Untersuchung der A. carotis, eine Echokardiographie, eine 24 h-Blutdruckmessung, ein 7 d-LZ-EKG und eine laborchemische Erhebung des Lipid- und Glukosestatus. Bei der Auswertung der 41 Patienten mit venösen Gefäßverschlüssen im Auge konnte wie auch in vergleichbaren Studien gezeigt werden, dass vor allem die arterielle Hypertonie, der Nikotinkonsum, die Hyperlipidämie und der Diabetes mellitus die wichtigsten kardiovaskulären Risikofaktoren darstellen. Zudem wurde durch die verlängerte elektrokardiographische Aufzeichnungsdauer über sieben Tage mehr als ein Drittel aller Patienten mit Herzrhythmusstörungen identifiziert. Anhand der Ergebnisse der vorliegenden Studie sind apparative Untersuchungen wie eine 24 h-Blutdruckmessung, eine Echokardiographie und ein 7-Tage-Langzeit-EKG unverzichtbar. Laborchemisch sollten ein Lipidstatus und ein Blutzuckerprofil routinemäßig erhoben werden. Zur Einschätzung des kardiovaskulären Risikos des Patienten erscheint eine Untersuchung der A. carotis sinnvoll. Um die Morbidität und die Mortalität zu senken bedarf es einer interdisziplinären Ursachenabklärung, welches die enge Zusammenarbeit zwischen Ophthalmologen und Internisten erfordert. Vergleicht man die FIND-AF-EYE-Studie mit der bereits publizierten FIND-AF-Studie litten die Patienten der FIND-AF-Studie signifikant häufiger an einer Karotisstenose. Zusammenfassend lässt sich sagen, dass akuten arteriellen Verschlüssen, wie beispielsweise einer zerebralen Ischämie, in den meisten Fällen thromboembolische Ereignisse zugrunde liegen. Kardiovaskuläre Risikofaktoren spielen aber auch bei venösen Gefäßverschlüssen im Auge eine wichtige Rolle. Hierbei führen sie zu arteriosklerotischen Veränderungen der eng benachbarten Zentralarterie. Durch die Kompression kommt es somit zur Thrombenbildung in der Zentralvene.
198

Η εκτίμηση με οπτική συνεκτική τομογραφία των ένοχων βλαβών μοσχευμάτων ασθενών με οξύ στεφανιαίο σύνδρομο και προηγηθείσα αορτοστεφανιαία παράκαμψη / Evaluation of culprit saphenous vein graft lesions with optical coherence tomography in patients with acute coronary syndromes

Δαμέλου, Αναστασία 26 July 2013 (has links)
Στο συγκεκριμένο ερευνητικό πρωτόκολλο μελετήθηκαν οι πιθανές ένοχες βλάβες σε φλεβικά μοσχεύματα ασθενών με οξέα στεφανιαία σύνδρομα με τη μέθοδο της Οπτικής Συνεκτικής Τομογραφίας (OCT). • Οι αθηροσκληρωτικές βλάβες των φλεβικών μοσχευμάτων έχουν μελετηθεί in vivo με τη μέθοδο της αγγειοσκόπησης και της ενδαγγειακής υπερηχογραφίας (IVUS). Απεναντίας, η απεικόνιση των μοσχευμάτων με τη μέθοδο της OCT, η οποία χαρακτηρίζεται από σημαντικά μεγαλύτερη διακριτική ικανότητα σε σχέση με το IVUS και βελτιωμένη διεισδυτική ικανότητα συγκρινόμενη με την αγγειοσκόπηση, δεν έχει μελετηθεί συστηματικά. • Μέθοδος: Η απεικόνιση των ένοχων βλαβών των μοσχευμάτων πραγματοποιήθηκε, κατόπιν αγγειογραφίας τους, με τη μέθοδο χωρίς απόφραξη της OCT σε ασθενείς με ασταθή στηθάγχη (UA), έμφραγμα μυοκαρδίου με ανάσπαση του διαστήματος ST (STEMI) και έμφραγμα μυοκαρδίου χωρίς ανάσπαση του διαστήματος ST (non-STEMI). Ο ινώδης ιστός, ο λιπώδης ιστός, οι εναποθέσεις ασβεστίου, ο θρόμβος και η ρήξη της πλάκας ορίστηκαν σύμφωνα με τα κριτήρια απεικόνισης στοιχείων για την OCT, όπως περιγράφηκαν και στο γενικό μέρος. • Αποτελέσματα: Απεικονίστηκαν 28 φλεβικά μοσχεύματα (μέσης ηλικίας 14.6 ετών) σε 26 ασθενείς. Οι βλάβες χαρακτηρίστηκαν ως σύμπλοκες αγγειογραφικά σε ποσοστό 96.4%, ενώ εμφάνιζαν εξέλκωση σε ποσοστό 32.1% και θρόμβο σε ποσοστό 21.4%. Η OCT αποκάλυψε ινολιπώδη σύσταση σε όλες τις βλάβες, εναπόθεση ασβεστίου στο 32.1% των βλαβών, ρήξη πλάκας σε ποσοστό 60.7% και παρουσία θρόμβου σε ποσοστό 46.4%. Η παρουσία του θρόμβου ήταν προοδευτικά συχνότερη ανάμεσα στις ομάδες ανάλογα με το κλινικό τους σύνδρομο (UA έως STEMI, p=0.003, UA έναντι εμφράγματος μυοκαρδίου, p=0.006). Η λεπτή ινώδης κάψα καταγράφηκε οριακά συχνότερα στους ασθενείς με οξύ έμφραγμα μυοκαρδίου (UA έναντι εμφράγματος μυοκαρδίου, p=0.06, STEMI 100% έναντι non-STEMI 53.3% έναντι UA 20%, p=0.03). Βλάβες με στοιχεία ευθρυπτότητας, όπως απεικονίζονταν στην OCT παρουσιάζονταν σε ποσοστό 67.9%, χωρίς όμως συσχέτιση με την κλινική εικόνα. • Συμπέρασμα: Οι ένοχες βλάβες φλεβικών μοσχευμάτων μεγάλης ηλικίας ασθενών με οξέα στεφανιαία σύνδρομα, όπως αυτές απεικονίζονται στην OCT, εμφανίζουν ινολιπώδη σύσταση, σχετικά λεπτή ινώδη κάψα, ρήξη πλάκας και θρόμβο που συσχετίζονται με το κλινικό φάσμα των οξέων στεφανιαίων συνδρόμων. Αυτά οδηγούν στο συμπέρασμα ότι οι ίδιοι μηχανισμοί αθηροσκλήρωσης που οδηγούν στην εμφάνιση οξέων στεφανιαίων συνδρόμων στα γηγενή στεφανιαία αγγεία, είναι πιθανόν να ενέχονται και στην πρόκληση οξέων στεφανιαίων συνδρόμων λόγω αποτυχίας των φλεβικών μοσχευμάτων. / This study sought to assess, with optical coherence tomography (OCT), presumably culprit atherosclerotic lesions of saphenous vein grafts (SVGs) in patients with acute coronary syndromes (ACS). Background: Atherosclerotic lesions of SVGs have been studied in vivo with angioscopy and intravascular ultrasound. However, imaging with OCT, which has a higher resolution than intravascular ultrasound and better penetration than angioscopy, has not been conducted systematically. Methods Using a nonocclusive OCT technique, we performed angiography and OCT of culprit SVG lesions in patients with unstable angina (UA), ST-segment elevation myocardial infarction (STEMI), and non-STEMI. Fibrous and fatty tissue, calcification, thrombus, and plaque rupture were defined according to OCT objective criteria. Results: Twenty-eight SVGs (average age 14.6 years) in 26 patients were imaged. Lesions on angiography were complex (96.4%), with ulceration in 32.1% and thrombus in 21.4%. OCT disclosed a fibrofatty composition in all lesions, calcification in 32.1%, plaque rupture in 60.7%, and thrombus in 46.4%. Thrombus was progressively more frequent across groups (UA to STEMI, p=0.003; UA vs. myocardial infarction, p=0.006). A thin fibrous cap was marginally more frequent in myocardial infarction patients (UA vs. myocardial infarction, p=0.06; STEMI 100% vs. non-STEMI 53.3% vs. UA 20%, p=0.03). OCT features of friability were present in 67.9% of SVGs not correlating with clinical presentation. Conclusions: OCT of culprit lesions of old SVGs in patients with ACS demonstrates fibrofatty composition, relatively thin fibrous cap, plaque rupture, and thrombus, which correlate with the clinical spectrum of ACS. This suggests that similar mechanisms with native vessels’ atherosclerosis may be involved in SVG-related ACS.
199

Ecoescleroterapia com espuma de polidocanol em veia safena magna com cateter curto versus cateter longo com tumescência: ensaio clínico randomizado / Polidocanol foam echosclerotherapy of the great saphenous vein with short catheter versus long catheter with tumescence: randomized controlled trial

Santos, Jorgete Barreto dos 06 December 2018 (has links)
INTRODUÇÃO: A ecoescleroterapia com espuma (EEE) é um método minimamente invasivo de tratamento das varizes dos membros inferiores. Suas principais vantagens são a indicação para pacientes com alto risco cirúrgico, recuperação precoce pós-intervenção e menor custo inicial em relação aos outros métodos endovenosos. Porém, a taxa de oclusão venosa é variável, especialmente para o eixo venoso troncular com diâmetro maior que 6 mm. OBJETIVO: Comparar duas técnicas de EEE de polidocanol a 3% em veia safena magna (VSM) insuficiente, tendo como desfecho primário a taxa de sucesso completo com uma sessão terapêutica e desfechos secundários a avaliação da qualidade de vida e a taxa de complicações. PACIENTES E MÉTODOS: Seleção de 50 pacientes com varizes primárias superficiais em membro inferior (CEAP - classificação clínica, etiológica, anatômica, patofisiológica - C3) e insuficiência da VSM (6 - 10 mm de diâmetro) medida a 3 cm da junção safenofemoral. Trata-se de um estudo prospectivo, controlado e randomizado realizado no ambulatório do Serviço de Cirurgia Vascular e Endovascular do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Os participantes foram submetidos à EEE preparada pelo método de Tessari. No grupo controle, a injeção foi realizada com uma agulha 18G enquanto que, no grupo alvo, foi utilizado um cateter angiográfico multipurpose 4 Fr., precedendo-se à tumescência salina anestésica no compartimento da VSM, e irrigação contínua do cateter com solução salina antes da injeção da espuma esclerosante. A flebectomia das tributárias varicosas foi realizada em todos os pacientes em nível ambulatorial sob anestesia local tumescente. RESULTADOS: A EEE com cateter angiográfico, precedida de tumescência salina anestésica, com uma única sessão terapêutica, apresentou taxa de sucesso completo superior ao grupo controle (80% versus 36%) com significância estatística (p = 0,012). Houve melhora na qualidade de vida em ambos os grupos. (p < 0,001). Não houve diferença estatística entre os grupos na taxa de complicações (p = 0,584). CONCLUSÕES: A EEE com cateter longo em VSM, precedida de tumescência ecoguiada é um método seguro e eficaz. Apresenta maior taxa de sucesso completo da veia alvo com uma sessão terapêutica em comparação à técnica com cateter curto / INTRODUCTION: Foam echoesclerotherapy is a minimally invasive method to treat varicose veins of the legs. Its main advantages are indication for patients with high surgical risk, early recovery after intervention and lower initial cost in comparison to other endovenous methods. However, the vein occlusion rate is variable, notably for the truncal venous axis with diameter greater than 6 mm. OBJECTIVES: To compare two techniques of echoesclerotherapy with 3% polidocanol foam for the incompetent great saphenous vein (GSV), having as primary outcome the full success rate with one treatment session and secondary outcomes the quality of life and the complication rates. PATIENTS AND METHODS: Selection of 50 patients with primary superficial varicose veins of the leg (clinical, etiologic, anatomic, pathophysiologic - CEAP - classification C3) and GSV incompetence (6-10 mm diameter) measured at 3 cm distal from the saphenofemoral junction. This was a prospective, controlled and randomized trial conducted on the outpatient clinic, Division of Vascular and Endovascular Surgery, University of São Paulo. Patients underwent foam echoesclerotherapy prepared according to the Tessari method. In control group, the injection was performed with an 18G needle whereas in target group, a multipurpose angiographic catheter 4 Fr. was used, preceded by saline anaesthetic tumescence in the GSV compartment, and continuous catheter flush with saline solution before the sclerosing foam delivery. Phlebectomy of the varicose tributaries was performed under local tumescent anaesthesia on outpatient setting. RESULTS: Foam echoesclerotherapy with the angiographic catheter, preceded by saline anaesthetic tumescence yielded complete success rate with a single treatment session higher than the control group (80% versus 36%) with statistical significance (p = 0.012). There was improvement in quality of life in both groups (p < 0.001). There was no statistical difference between the groups in complication rates (p=0.584). CONCLUSIONS: Sclerotherapy with the long catheter, preceded of ultrasound-guided tumescence in the GSV compartment, is a safe and effective method. It yielded higher full success rate of the target vein with a single treatment session in comparison to the short catheter technique
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Aumento da IL-1beta no processo de arterialização de enxertos venosos utilizando modelos ex vivo, in vitro e in vivo / Increased IL-1beta during vein grafts arterialization: study of ex vivo, in vitro and in vivo models

Borin, Thaiz Ferraz 24 January 2008 (has links)
A revascularização cardíaca utilizando a ponte de safena é um procedimento bastante comum usado para restabelecer o fluxo coronariano. O sucesso do implante depende da adaptação do vaso que estava em um regime hemodinâmico venoso, e passa subitamente para um regime arterial. Durante este processo adaptativo, ocorrem diversas alterações moleculares cujo conhecimento pode fornecer alternativas de melhoramento da patência dos enxertos venosos em leito arterial. Neste trabalho está sendo investigada a regulação da IL-1beta tanto em veia safena humana como em modelo animal de arterialização venosa. A IL-1beta mostrou-se aumentada em veia safena humana arterializada tanto in vivo como ex vivo. Interessantemente, este aumento observado nos dias iniciais (1-5 dias) parece diminuir em tempos mais tardios (1-4 anos). Em modelo de arterialização de rato foi observado aumento de 12 vezes na expressão da IL-1beta após o primeiro dia de arterialização com diminuição posterior, mantendo-se em torno de 2 vezes maior em comparação a veia jugular normal. Além da regulação temporal da IL-1beta, foram também acompanhadas as alterações morfológicas que ocorrem durante o processo de arterialização venosa. Observou-se uma redução gradual de células musculares lisas (SMC) que quase desaparecem 3 dias após a cirurgia. Esta perda celular pode estar relacionada ao pico de apoptose observado já no primeiro dia de arterialização. Após 7 dias as SMC reaparecem, porém, de maneira ainda desorganizada. Concomitante com o reaparecimento das SMC observou-se progressivo espessamento da camada média, assim como surgimento de uma camada neoíntima. A IL-1beta, devido ao seu padrão de regulação assim como sua localização durante o processo de arterialização, pode estar relacionada com as alterações estruturais verificadas na arterialização do enxerto. Estratégias de intervenção modulando a atividade da IL-1beta poderão fornecer indicativos da sua participação no remodelamento do enxerto venoso. Em conjunto, demonstramos que o modelo de arterialização de segmento venoso em rato reproduz várias das alterações morfológicas descritas na doença do enxerto venoso em humanos e por isso será útil na caracterização de genes candidatos que participam deste processo. A IL-1beta tem sua expressão aumentada em segmento venoso arterializado in vivo e ex vivo, podendo representar um interessante alvo para aplicação de metodologias de intervenção visando influenciar a adaptação de enxertos venosos com finalidade terapêutica / The vein graft is subjected to increased tensile stress and the complex adaptive vein response to the arterial hemodynamic condition may predispose to bypass failure in some individuals. The understanding of molecular changes underlying this process may be useful for the development of novel therapeutical interventions to increase the vein graft patency. In this work, we investigated the early effect of arterialization on the expression of IL-1beta gene in human saphenous vein and the time-course regulation in rat arterialization model. IL-1beta is upregulated in early stage of human saphenous vein arterialization in vivo and ex vivo. This increase is also observed in arterialized rat jugular vein which showed IL-1beta expression 12 times higher on day 1 compared to normal jugular vein. Later, the IL-1beta levels decreases and maintain the level about twice above normal jugular vein. Moreover, it is observed gradual reduction of smooth muscle cells (SMC), which almost disappeared on the 3rd day after surgery. Apoptosis, which is markedly increased on the 1st day, appears to be an important event during this process. At the 7th day, cellular density and SMC proliferation gradually increased till the 90th day. There was a gradual thickening of the medial layer and formation of neointima with deposition of SMC in the subendotelial layer from day 7 on. Initially the medial layer appeared disorganized, day 7 to 14, then by day 28 it became more organized and the presence of an intimal layer with SMCs was evident. The neointimal layer increased gradually from day 7 on. These results provide evidence that the modulation of IL-1beta activity may be an interesting target to be explored I the future to increase the vein graft patency. Altogether, we demonstrate that the model of arterialization of venous segment in rat reproduces several of the morphological changes described in the venous graft disease in humans and thus will be useful in characterization of candidate genes involved in this process and testing them as a potential therapeutic targets. The IL-1beta expression is increased after 1 day of arterialization of vein segment in vivo and ex vivo and shall be an interesting target to be tested to influence the adaptation of venous grafts for therapeutic purpose

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