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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.
111

Comparação entre abordagem do nervo maxilar pelo forame infraorbitário e pela fossa pterigopalatina ventral em cabeças de cavalos utilizando o corante azul de metileno

Robayo Trujillo, Manuel Eduardo Tadeo January 2015 (has links)
A anestesia do nervo maxilar no cavalo já foi descrita por diferentes autores usando várias aproximações, mas não existem muitos estudos que avaliaram sua eficácia e confiabilidade. Alguns autores consideram que dessensibilizar o nervo maxilar é difícil e pouco confiável devido a quadrantes mal definidos para a infiltração, enquanto que outros o tem descrito como potencialmente perigoso devido à proximidade com órbita e o risco de infecções. Uma alternativa seria o acesso ao nervo maxilar pelo forame infraorbitário utilizando um cateter, da mesma maneira como já realizado em cães, e com resultados bem-sucedidos. Sendo assim, o presente trabalho objetivou comparar o bloqueio do nervo maxilar pela fossa pterigopalatínica (BAPFPV) ou pelo forame infraorbitário com o uso de um cateter venoso (BFIC) em cavalos. Para tal, foram utilizadas 12 cabeças de cavalos adultos. Em cada lado da cabeça foram realizados um dos bloqueios propostos utilizando o corante azul de metileno para demarcar a área de abrangência do bloqueio. Todos os bloqueios foram realizados por veterinários sem experiência prévia. Os resultados foram avaliados mediante a dissecção dos nervos expostos ao longo do canal infraorbitário e até a fossa pterigopalatínica. Foram realizadas duas mensurações, uma determinando o comprimento (milímetros) de nervo corado com azul de metileno e a segunda avaliando o grau de impregnação do nervo pelo corante, sendo esta determinada como muito corada, parcialmente corada e não corada. O grupo BFIC apresentou média de 10,75 ± 8,08mm e o grupo BAPFPV 16,08 ± 17,22mm de impregnação do nervo maxilar pelo azul de metileno. Quanto ao grau de impregnação do nervo pelo corante, no grupo BFIC 33,3% apresentaram o nervo muito corado, 58,3% parcialmente corado e 8,3% não corado. Já no grupo BAPFPV, 41,7% apresentaram o nervo muito corado, 8,3% parcialmente corado e 50% não corado. Não foi verificada diferença estatisticamente significativa entre os grupos tanto no comprimento quanto no grau de impregnação do nervo pelo corante. Foi observado um caso de infiltração intravascular dos vasos maxilares e quatro casos de impregnação do corante na gordura retrobulbar no grupo BAPFPV. Não foram observadas essa outras complicações no grupo BFIC. De acordo com as condições experimentais deste estudo é possível concluir que as duas abordagens atingem o nervo maxilar de maneira similar, entretanto, em virtude dos resultados promissores da técnica BFIC e dos menores riscos, recomendamos a realização de estudos clínicos para a sua utilização na rotina equestre. / A number of authors using several approaches has described anaesthesia of the maxillary nerve of the horse, but it does not have many studies to evaluate its efficacy and reliability. Some authors consider desensitising the maxillary nerve to be difficult and unreliable due to poorly defined landmarks for injection, while others have also described it as potentially dangerous due to the proximity of the orbit and risk of infection. An alternative would be the approach to the nerve along the infraorbital foramen with a catheter, just as was done in dogs with successful results. Therefore, this study aimed to compare the maxillary nerve block by PTERYGOPALATINE FOSSA (BAPFPV) or the infraorbital foramen using a venous catheter (BFIC) in horses. For this purpose, were uses twelve adult horses heads. In each side of the head was carried one of the proposed blocks using the methylene blue dye to mark the area covered by the block. All blocks were performed by veterinarians without prior experience. The results were evaluated by the dissection of the exposed nerves along the infraorbital canal to the PTERYGOPALATINE FOSSA. Two measurements wre made, one determined the length (millimeters) of the nerve stained with methylene blue dye and the second evaluated the degree of impregnation by the nerve with the dye, and it was classified as highly stained, partially stained and unstained. The BFIC group presented an average of 10.75 ± 8,08mm and the BAPFPV group 16.08 ± 17,22mm of maxillary nerve impregnation by methylene blue dye. The degree of impregnation by the nerve with the dye, the BFIC group had 33,3% of the nerve highly stained, 58,3% partially stained and 8,3% unstained. At the BAPFPV group, 41,7% had the nerve highly stained, 8,3% partially stained and 50% stained. There was no statistical significant difference between the groups in both the length and degree of dye impregnation by the nerve. A case of intravascular infiltration of the maxillary vessels and four cases of retrobulbar fat dye impregnation in BAPFPV group was observed. These complications were not seen in the BFIC group. According to the experimental conditions of this study it was concluded that both approaches reach the maxillary nerve in a similar manner, however, due to the promising results of BFIC technique and lower risks, we recommend clinical studies for its use in routine equestrian.
112

National Trend in Multivessel Percutaneous Coronary Intervention in Patients with Diabetes Mellitus in the United States

Mogusu, Eunice, Abusara, Ashraf, Panchal, Hemang, Zheng, Shimin, Paul, Timir K. 06 April 2016 (has links)
Patients with diabetes and multivessel coronary artery disease treated with multivessel percutaneous coronary intervention (MVPCI) have higher mortality, non-fatal myocardial infarction and repeat revascularization rates compared to coronary artery bypass graft surgery (CABG). This is also associated with high hospital costs. The objective of our study was to assess and compare the proportions and trends 2016 Appalachian Student Research Forum Page 83 of MVPCI in diabetic and all PCI patients and the total charges associated with them. Data were retrieved from nationwide inpatient sample from 2006-2011, which is a 20% stratified probability sample of discharges in all community hospitals participating in Healthcare Cost and Utilization Project. International Classification of Diseases 9 codes were used to identify diabetic patients who underwent percutaneous coronary intervention with stents in two or more vessels. Patients with a history CABG surgery, cardiac transplant and those who were below 18 years of age were excluded from this study. Bivariate analyses were computed for demographics and various diagnosis and procedures. Trends were computed for the proportions of diabetic and all patients that received stents in single, 2 or more and 3 or more vessels and for total charges for the 24 quarters. Between 2006 and 2011, a total of 145,349 diabetic patients underwent single vessel PCI with a mean age of 63.96 ± 11.70, 40.9% females and 59.1% males. 41,325 diabetic patients underwent = 2 vessels PCI, mean age 64.63 ± 11.64, 39.1% females and 60.9% males. 2,406 diabetic patients underwent = 3 vessels with a mean age of 64.92 ± 11.81 and 38.5% females and 61.5% males. The mean total charges for all single vessel PCI patients for the period was on a steady rise with a mean of $51,584.06 in the 1st quarter 2006 and $77,075.88 in the 24th quarter, 2011. Likewise, the trend for =2 vessel PCI group steadily increased from a mean of $61,089 to $91,937 and those for =3 vessel PCI group up from $73,532.08 to $105,364 through the period. For the diabetic PCI patients, charges associated with the single vessel PCI were on the upward trend with a mean of $53,217 in the 1st quarter to $81,040 in the 24th quarter. Similarly, the mean total charges associated with =2 vessel diabetic PCI group increased from $62,442 to $93,427 and from $78,401 to $110,015 for the =3 vessel diabetic PCI group across the period. There was a steady increase in the total charges for both single vessel and MVPCI procedures performed on diabetic and all patients between 2006 and 2011. The results of this study can be used to assess health care delivery cost and to inform policy to reduce cost.
113

Stent pour implantation percutanée d'une valve cardiaque / Stent for percutaneous heart valve implantation

Marchand, Coralie 22 May 2009 (has links)
Cette étude à pour but de développer un concept de stent atraumatique pour le remplacement percutanée de la valve aortique. Le stent est obtenu à partir de brins de Nitinol tressés, ce qui lui permet, de part sa géométrie et sa structure, d'être compressible, auto-expansible, et atraumatique. Le principe de fabrication des prototypes et les contraintes qui lui est associé sont présentées. Les performances de ces prototypes, en terme d'ancrage, de régurgitation statique et de régurgitation dynamique sont ensuite évaluées par des essais in vitro, pour lesquel le banc de test en flux pulsé a été optimisé afin de prendre en considération la compliance de la racine aortique. Les résultats obtenus permettent de mettre en évidence les différents paramètres de fabrication stent, tant au niveau dimensionnel (hauteur du cylindre, angle du cône...) qu'au niveau structurel (rigidité), qui ont une influence significative sur le comportement de l'endoprothèse. / The goal of this work is to develop an atraumatic stent concept for percutaneous aortic valve replacement. Shape setted braided nitinol wires, thanks to their specific geometry and elasticity, allows stent's compressibility, self deployment and aortic root preservation. Prototypes manufacturing technique and relatives constraints are presented. Performance of the obtained prototypes are evaluated in vitro, in terms of sealing, static and dynamic regurgitation. More specifically, the pulsatile bench testing has been optimized to take in account the compliant constraint of the aortic valve environment. The results bring to the fore which are the dimensions (head height, cone angle...) and the structures features that do influence the endoprosthesis behavior significantly.
114

High intensity focused ultrasound (hifu) and ethanol induced tissue ablation: thermal lesion volume and temperature ex vivo

January 2013 (has links)
HIFU is the upcoming technology for noninvasive or minimally invasive tumor ablation via the localized acoustic energy deposition at the focal region within the tumor target. The presence of cavitation bubbles had been shown to improve the therapeutic effect of HIFU. In this study, we have investigated the effect of HIFU on temperature rise and cavitation bubble activity in ethanol-treated porcine liver and kidney tissues. We have also explored changes in the viability and proliferation rate of HepG2, SW1376, and FB1 cancer cells with their exposure to ethanol and HIFU. Tissues were submerged in 95% ethanol for five hours and then exposed to HIFU generated by a 1.1 MHz transducer or injected into focal spot before HIFU exposure. Cavitation events were measured by a passive cavitation detection technique for a range of acoustic power from 1.17 W to 20.52 W. The temperature around the focal zone was measured by type K or type E thermocouples embedded in the samples. In experiments with cancer cells, 2.7 millions cells were treated with concentration of ethanol at concentration 2%, 4%, 10%, 25%, and 50% and the cell were exposed to HIFU with power of 2.73 W, 8.72 W, and 12.0 W for 30 seconds. Our data show that the treatment of tissues with ethanol reduces the threshold power for inertial cavitation and increases the temperature rise. The exposure of cancer cells to various HIFU power only showed a higher number of viable cells 24 to 72 hours after HIFU exposure. On the other hand, both the viability and proliferation rate were significantly decreased in cells treated with ethanol and then HIFU at 8.7 W and 12.0 W even at ethanol concentration of 2 and 4 percent. In conclusion, the results of our study indicate that percutaneous ethanol injection (PEI) and HIFU have a synergistic effect on cancer cells ablation. / acase@tulane.edu
115

Percutaneous delivery of thalidomide and its N-alkyl analogues for treatment of rheumatoid arthritis / Colleen Goosen

Goosen, Colleen January 1998 (has links)
Thesis (PhD (Pharmaceutics))--PU for CHE, 1999.
116

The Role of Chlamydia pneumoniae-induced Platelet Activation in Cardiovascular Disease : In vitro and In vivo studies

Kälvegren, Hanna January 2007 (has links)
The common risk factors for atherosclerosis, such as obesity, high cholesterol levels, sedentary lifestyle, diabetes and high alcohol intake, only explain approximately 50% of cardiovascular disease events. It is thereby important to identify new mechanisms that can stimulate the process of atherosclerosis. During the past decades, a wide range of investigations have demonstrated connections between infections by the respiratory bacterium Chlamydia pneumoniae and atherosclerosis. Earlier studies have focused on the interaction between C. pneumoniae and monocytes/macrophages, T-lymphocytes, smooth muscle cells and endothelial cells, which are present in the atherosclerotic plaque. However, another important player in atherosclerosis and which is also present in the plaques is the platelet. Activation of platelets can stimulate both initiation and progression of atherosclerosis and thrombosis, which is the ultimate endpoint of the disease. The aim of the present thesis was to investigate the capacity of C. pneumoniae to activate platelets and its role in atherosclerosis. The results show that C. pneumoniae at low concentrations binds to platelets and stimulates platelet aggregation, secretion, reactive oxygen species (ROS) production and oxidation of low-density lipoproteins (LDL), and that these effects are mediated by lipopolysaccharide (LPS). Activation of protein kinase C, nitric oxide synthase and 12-lipoxygenase (12-LOX) was required for platelet ROS production, whereas platelet aggregation was dependent on activation of GpIIb/IIIa. Pharmacological studies showed that the C. pneumoniae-induced platelet activation is prevented by inhibitors against 12-LOX, platelet activating factor (PAF) and the purinergic P2Y1 and P2Y12 receptors, but not against cyclooxygenase (COX). These findings were completely opposite to the effects of these inhibitors on collagen-stimulated platelets. We also present data from a clinical study indicating that percutaneous coronary intervention (PCI or balloon dilatation) leads to release of C. pneumoniae into the circulation, which causes platelet activation and LDL oxidation. In conclusion, these data support a role for C. pneumoniae-induced platelet activation in the process of atherosclerosis. Stimulation of platelets by C. pneumoniae leads to release of growth factors and cytokines, oxidation of LDL and platelet aggregation, which are processes that can stimulate both atherosclerosis and thrombosis. Development of novel drugs that prevent C. pneumoniae-platelet interaction by inhibiting 12-LOX and/or PAF, may be important in the future treatment of cardiovascular disease.
117

Exploring the health behaviour practices of elective ad-hoc percutaneous coronary intervention (PCI) patients

Throndson, Karen Lynn 08 April 2011 (has links)
Interventional technologies such as elective percutaneous coronary interventions (PCI)are increasingly used to manage the symptoms of coronary artery disease (CAD); however, this treatment approach is associated with poor risk factor management. The purpose of this study was to understand the factors that influence the health behaviors of elective PCI patients. A qualitative approach, using Interpretive Description, was used to explore the ten participants’ healthcare experiences, their perceptions of CAD, and the rationale for their health choices. This generated a profile of these individuals and their post-PCI health behaviours. Health behaviours were influenced by multiple factors and are reflected in the themes: what a relief – I’m better; uncertainty about their future health; the importance of relations; and barriers to lifestyle change. These findings not only extend our understanding of the elective PCI patients’ health behaviour choices but also provides insight into key areas to target for improving health service delivery.
118

Percutaneous delivery of thalidomide and its N-alkyl analogues for treatment of rheumatoid arthritis / Colleen Goosen

Goosen, Colleen January 1998 (has links)
Rheumatoid arthritis (RA) is a chronic inflammatory joint disease associated with high levels of tumour necrosis factor-alpha (TNF-a) in synovial fluid and synovial tissue (Saxne et al., 1989). Thalidomide is a proven inhibitor of the biological synthesis of TNF-a (Sampaio et al., 1991) and is believed to rely on this action for its suppression of the wasting of tissue which accompanies RA. Oral administration of thalidomide has proven to be effective in RA, but unacceptable side effects are easily provoked (Gutierrez-Rodriguez, 1984). Administration of thalidomide via the dermal route can down-regulate TNF-a production in and around the affected joint, and this without raising the systemic blood level to a problematical level. Based on thalidomide's physicochemical properties, it is unlikely that it can be delivered percutaneously at a dose required for RA. Therefore, we have embraced the idea of using N-alkyl analogues of thalidomide. The most important feature that an analogue of this compound might contribute is decreased crystallinity and increased lipophilicity. Ordinarily both these parameters should favour percutaneous delivery. The current study was primarily aimed at exploring the feasibility of percutaneous delivery of thalidomide and subsequently, three of its odd chain IV-alkyl analogues (methyl, propyl and pentyl) via physicochemical characterization and assessment of their innate abilities to diffuse through skin as an initial step towards developing a topical dosage form for the best compound. The biological activities, more specifically their potential to inhibit the production of TNF-a was determined for thalidomide and its N-alkyl analogues. In order to achieve the objectives, the study was undertaken by synthesizing and determining the physicochemical parameters of thalidomide and its N-alkyl analogues. A high level of crystallinity is expressed in the form of a high melting point and heat of fusion. This limits solubility itself, and thus also sets a limit on mass transfer across the skin. Generally, the greater a drug's innate tendency to dissolve, the more likely it is that the drug can be delivered at an appropriate rate across the skin (Ostrenga et al., 1971). Therefore, the melting points and heats of fusion were determined by differential scanning calorimetry. Aqueous solubility and the partition coefficient (relative solubility) are major determinants of a drug's dissolution, distribution and availability. N-octanollwater partition coefficients were determined at pH 6.4. Solubilities in water, a series of n-alcohols and mixed solvents were obtained, as well as the solubility parameters of the compounds in study. Secondly, in vitro permeation studies were performed from these solvents and vehicles using vertical Franz diffusion cells with human epidermal membranes. Thirdly, tumour necrosis factor-alpha (TNF-a) inhibition activities were assessed for thalidomide and its N-alkyl analogues. By adding a methyl group to the thalidomide structure, the melting point drops by over 100°C and, in this particular instance upon increasing the alkyl chain length to five -CH2- units the melting points decrease linearly. Heats of fusion decreased dramatically upon thalidomide's alkylation as well. Methylation of the thalidomide molecule enhanced the aqueous solubility 6-fold, but as the alkyl chain length is further extended from methyl to pentyl, the aqueous solubility decreased exponentially. The destabilization of the crystalline structure with increasing alkyl chain length led to an increase in lipophilicity and consequently an increase in solubility in nonpolar media. Log partition coefficients increased linearly with increasing alkyl chain length. Solubilities in a series of n-alcohols, methanol through dodecanol, were found to be in the order of pentyl > propyl > methyl > thalidomide. The N-alkyl analogues have more favourable physicochemical properties than thalidomide to be delivered percutaneously. The in vitro skin permeation data proved that the analogues can be delivered far easier than thalidomide itself. N-methyl thalidomide showed the highest steady-state flux through human skin from water, n-alcohols and combination vehicles. Thalidomide and its N-alkyl analogues were all active as TNF-a inhibitors. Finally, active as a TNF-a inhibitor, N-methyl thalidomide is the most promising candidate to be delivered percutaneously for treatment of rheumatoid arthritis, of those studied. / Thesis (PhD (Pharmaceutics))--PU for CHE, 1999.
119

Exploring the health behaviour practices of elective ad-hoc percutaneous coronary intervention (PCI) patients

Throndson, Karen Lynn 08 April 2011 (has links)
Interventional technologies such as elective percutaneous coronary interventions (PCI)are increasingly used to manage the symptoms of coronary artery disease (CAD); however, this treatment approach is associated with poor risk factor management. The purpose of this study was to understand the factors that influence the health behaviors of elective PCI patients. A qualitative approach, using Interpretive Description, was used to explore the ten participants’ healthcare experiences, their perceptions of CAD, and the rationale for their health choices. This generated a profile of these individuals and their post-PCI health behaviours. Health behaviours were influenced by multiple factors and are reflected in the themes: what a relief – I’m better; uncertainty about their future health; the importance of relations; and barriers to lifestyle change. These findings not only extend our understanding of the elective PCI patients’ health behaviour choices but also provides insight into key areas to target for improving health service delivery.
120

Arterioveninių jungčių dializuojamiems pacientams funkcionavimo pailginimo galimybių tyrimas / Investigation of possibilities to extend functioning time of arteriovenous fistulas for hemodialysis patients

Kybartienė, Sondra 02 July 2012 (has links)
Darbo tikslas: nustatyti veiksnius, susijusius su arterioveninių jung¬čių (AVJ) dializuojamiems pacientams funkcionavimo trukme bei įvertinti jungčių funkcijos monitoravimo naudą jų funkcionavimo trukmei prail-ginti. Darbo uždaviniai: 1. Įvertinti AVJ funkcijos monitoravimo naudą jos funkcionavimo trukmei prailginti. 2. Nustatyti pirmosios hemodializės procedūros atlikimo būdo ryšį su paciento stacionarizavimo trukme. 3. Nustatyti veiksnius, susijusius su AVJ funkcionavimo trukme. 4. Nustatyti centrinės venos kateterio buvimo ir lokalizacijos reikšmę AVJ funkcionavimo trukmei. 5. Įvertinti AVJ „brandinimo“ trukmės ryšį su AVJ funkcionavimo trukme. 6. Įvertinti priešoperacinio kraujagyslių ultragarsinio ištyrimo reikšmę pirminių jungties disfunkcijų išsivystymui bei AVJ funkcionavimo trukmei. DARBO METODIKA Tyrimas atliktas Lietuvos sveikatos mokslų universiteto Nefrologijos klinikoje, gavus Kauno regioninio tyrimų etikos komiteto leidimą Nr. BE 2-20. Dalis duomenų buvo renkama retrospektyviai, naudojant medicinos dokumentaciją, kita dalis informacijos apie pacientų laboratorinių tyrimų duomenis bei HD procedūros parametrus buvo renkama viso tyrimo ei¬goje. Visos AVJ pagal buvo suskirstytos į tris grupes: 1. Istorinė grupė – monitoravimas taikytas nebuvo (187 pacientai, 260 AVJ); 2. Monitoruota grupė – AVJ buvo monitoruojamos nuo pirmosios per ją atliktos HD (29 pacientai, 31 AVJ); 3. Dalinai monitoruota grupė – AVJ naudojamos HD iki 2008 m. gruo-džio 31 d., o vėliau... [toliau žr. visą tekstą] / Patients to be treated with chronic hemodialysis (HD) must have blood vessel connection. There are three types of blood vessel connections: native arteriovenous fistula (AVF), synthetic prosthesis and permanent central venous catheter. Each connection has its strengths and weaknesses. Primary AVF dysfunction occurs in 7.5% of the whole population of patients receiving HD, and in up to 80% of high risk patients (those with diabetes, elderly patients, and women) [Mann et al 2005]. Compared to other blood vessel connections (permanent central venous catheter or synthetic prosthesis) function of properly formed AVF is the longest, and incurs the lowest incidence of infectious and thrombotic complications. All international guidelines on HD procedures recommend native AVF as the method of choice. Formation of blood vessel junctions and treatment of their complications account for up to 20% of all hospitalizations of patients with end stage renal failure in USA [Allon et al 2002], up to 30% in Canada [Mann et al 2005], and up to 25% in Europe [Pissoni et al 2002]. It should be stated that formation of AVF and treatment of their complications are very expensive, and therefore determining the causes of the development of AVF complications and their timely diagnosis and correction are extremely important. Various methods of monitoring of AVF function are used in many European and USA HD centers; however, the most important criterion of early diagnosis of AVF complications has not... [to full text]

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