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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.
51

Desenvolvimento de formulações tópicas fotoquimioprotetoras contendo extrato de própolis: estudos de estabilidade, permeação e retenção cutânea in vitro e de eficácia in vivo / Development of photochemoprotective topical formulations containing propolis extract: in vitro stability, permeation and retention and in vivo efficacy studies

Marquele Oliveira, Franciane 27 September 2007 (has links)
A exposição à radiação ultravioleta (RUV) pode levar a um desequilíbrio no balanço oxidante/antioxidante da pele causando prejuízos à sua integridade e levando a diversas alterações, entre as quais o envelhecimento precoce e o câncer de pele. Na tentativa de diminuir os efeitos biológicos mediados pelos radicais livres gerados pela RUV na pele, tem sido proposto a fotoquimioproteção com a utilização de antioxidantes tópicos. Dentre a gama de compostos disponíveis para serem empregados na fotoquimioproteção, a própolis, por sua pronunciada atividade antioxidante, entre suas inúmeras atividades biológicas, é uma matéria-prima com promissora ação tópica. Desta forma, extratos de própolis alcoólico e glicólico (EPA e EPG) foram caracterizados quanto à sua composição polifenólica e quanto à sua capacidade antioxidante frente a diversos radicais livres. Formulações adicionadas destes extratos foram desenvolvidas e submetidas a estudos de estabilidade física e funcional, estudos de liberação, permeação e retenção cutânea in vitro, bem como estudos preliminares de eficácia in vivo. Os resultados demonstraram que os extratos de própolis são capazes de seqüestrar eficientemente diversos radicais livres, principalmente radicais superóxido. Quando estes extratos foram adicionados em formulações de produtos para uso tópico, a atividade antioxidante foi mantida. Nos estudos prévios de estabilidade física foi observado que as formulações mais estáveis foram desenvolvidas com Hostacerin® SAF (menor conteúdo graxo) e Polawax® (maior conteúdo graxo). No entanto, somente a formulação desenvolvida com Polawax® apresentou estabilidade satisfatória por 1 ano quando armazenada à temperatura ambiente e a 40º.C 2º.C/70%UR 5%. Nos estudos de liberação, permeação e retenção cutânea foi observado a influência do conteúdo graxo na performance das formulações. A cinética de liberação das formulações tanto do ácido p-cumárico (utilizado como marcador), como dos compostos equivalentes ao extrato de própolis (EEP) demonstraram seguir o modelo de Higuchi. A formulação desenvolvida com Polawax® apresentou a melhor retenção cutânea, com retenção de 0,013 e 0,030 µL de EEP.cm-2 para as peles de camundongo e de porco, respectivamente. Em adição, esta formulação apresentou baixos níveis de permeação cutânea, sendo adequada para aplicação tópica fotoquimioprotetora. Nos estudos in vivo, esta formulação adicionada de EPA, foi capaz de diminuir o eritema, inibir o edema e aumentar a cicatrização de camundongos sem pêlo expostos à radiação UVB. Além disso, também foi observado a proteção da depleção da glutationa endógena (GSH). Os resultados preliminares de eficácia in vivo sugerem que formulações contendo o extrato de própolis apresentam boas perspectivas para serem utilizadas para prevenir e tratar os danos causados na pele pela radiação UV. / The ultraviolet radiation (UVR) exposition may lead to the skin oxidant/antioxidant imbalance injuring its integrity and leading to several disorders, such as ageing and skin cancer. In order to improve the biological effects caused by free radicals generated by UVR in skin, it has been suggested the photochemoprotection by using topical antioxidants. Among the available compounds to be employed in hotochemoprotection, propolis, due to its important antioxidant activity, among its innumerous biological activities, is a promising topical raw-material. Next, ethanolic and glycolic propolis extracts (EPE, GPE) were characterized in relation to their polyphenolic composition, and in relation to their antioxidant activity against several free-radicals. Formulations added with these extracts were developed and undergone to physical and functional stability studies, in vitro release and skin permeation and retention studies, as well as in vivo preliminary efficacy studies. The results showed that the propolis extracts are able to scavenge several free radicals efficiently, mainly superoxide radicals. When these extracts were added to formulations of topical products, their antioxidant activity were maintained. In the physical stability studies, it was observed that the most stable formulations were developed with Hostacerin® SAF (lower fat content) and Polawax® (higher fat content). However, only the formulation developed with Polawax® showed satisfactory stability for 1 year stored at room temperature and at 40º.C 2º.C/70%UR 5%UR. In the release, permeation and retention studies, it was observed the fat content influence in the formulation performance. The release profile of p-coumaric acid (used as marker compound) and the compounds equivalent to propolis extract (EPE) followed the Higuchi model. The formulation developed with Polawax® showed the best skin retention, retaining 0,013 and 0,030 L EPE.cm-2 in hairless mouse skin and in pig skin, respectively. In addition, this formulation presented low permeation, which is desired for photochemoprotective topical employment. In the in vivo studies, this formulation added with EPE was able to diminish erithema, inhibit oedema and increase cicatrisation in hairless mice exposed to UVB radiation. In addition, it was also observed the protection of the endogenous glutathione (GSH) depletion. The in vivo preliminary efficacy results suggest that formulations added with propolis extract present good perspectives to be employed to prevent and treat the injuries caused in skin by UV radiation.
52

Avaliação seriada por ultrassom intracoronário do suporte vascular bioabsorvível com eluição de novolimus DESolveTM / Serial assessment by intracoronary ultrasound bioresorbable coronary scaffold eluting with novolimus DESolveTM

Aguiar Filho, Gentil Barreira de 03 October 2017 (has links)
INTRODUÇÃO: Os suportes vasculares bioabsorvíveis (SVB) surgiram com a finalidade de aumentar a segurança tardia das intervenções coronárias percutâneas (ICP). Estes dispositivos liberam o fármaco antiproliferativo no local da obstrução e são absorvidos com o passar do tempo. A utilização do ultrassom intracoronário (USIC) pode ajudar na avaliação do processo de absorção deste dispositivo. OBJETIVOS: Primário: avaliar e comparar, pelo USIC, o volume e a área da luz, do vaso e do SVB imediatamente após o implante da prótese, e, tardiamente, aos 6 e 18 meses. Objetivos secundários: avaliar e comparar, pelo USIC, o volume e área da placa imediatamente após o implante da prótese, e, tardiamente, aos 6 e 18 meses e os diâmetros do vaso, lúmen e SVB após ICP e no seguimento. Percentual de estenose e perda tardia do lúmen pela angiografia no seguimento e incidência de eventos cardíacos adversos maiores (ECAM) até os 18 meses. MÉTODO: Trata-se de um estudo prospectivo, não randomizado com a inclusão de 20 pacientes que foram submetidos ao implante do SVB DESolve®. Foi realizado o USIC após o procedimento e aos 6 e 18 meses de seguimento. RESULTADOS: Dos 20 pacientes selecionados, um paciente recusou realizar o USCI aos 6 meses e dois não realizaram o exame aos 18 meses, sendo excluídos do estudo. Totalizando 17 pacientes analisados. A idade média foi de 58,59 ± 8,73 anos e 70,6% eram do sexo masculino. O quadro clínico predominante era de angina estável. A via de acesso preferencial foi a radial, todos os pacientes foram submetidos à pré e pós-dilatação e o sucesso angiográfico ocorreu em todos os casos. No seguimento, houve aumento significativo na área (6,41 ± 1,35 mm2 vs. 7,35 ± 1,53 mm2, p < 0,002), volume (101,19 ± 20,9 mm3 vs. 118,51 ± 26,6 mm3, p = 0,001) e diâmetros do dispositivo, pelo USIC, aos 6 meses quando comparado ao procedimento índice. Não houve alteração significativa nas áreas, nos volumes e nos diâmetros do vaso e lúmen, em qualquer comparação no seguimento. A perda tardia foi de 0,22 ± 0,30 mm aos 6 e de 0,33 ± 0,44 mm aos 18 meses. Não houve nenhum caso de reestenose angiográfica e trombose do dispositivo. No seguimento, não houve casos de ECAM. CONCLUSÕES: A ICP com a utilização do SVB DESolve® para o tratamento da doença arterial coronária não complexa demonstrou resultados promissores. Houve aumento do volume e área do dispositivo aos 6 meses e uma supressão eficaz da hiperplasia intimal sem ECAM no seguimento. / INTRODUCTION: The bioresorbable vascular scaffolds (BVS) emerged in order to increase late safety of percutaneous coronary interventions (PCI). These devices release the antiproliferative drug to the site of obstruction and are absorbed over time. The use of intravascular ultrasound (IVUS) can help in the evaluation of this device absorption process. OBJECTIVES: The primary endpoint was to evaluate and compare, through IVUS, the volume and the area of the lúmen, the vessel and the device immediately after its implantation, and later at 6 and 18 months. The secondary endpoints were to evaluate and compare, through IVUS, the volume and the area of the plaque immediately after its implantation, and later at 6 and 18 months and diameters of the vessel, lúmen and BVS after PCI and at follow-up. Percentage of stenosis and late lúmen loss by angiography and incidence of major adverse cardiac events (MACE) up to 18 months. METHOD: This is a prospective, non-randomized study, with the inclusion of 20 patients who underwent implantation of DESolveTM. IVUS was performed after the procedure and at 6 and 18 months of follow-up. RESULTS: Of the 20 patients selected, one patient refused to perform the USCI at 6 months and two did not undergo the exam at 18 months and were excluded from the study. In total, 17 patients were analyzed. The average age was 58.59 ± 8.73 years and 70,6% were male. The most common clinical presentation was stable angina. The preferred vascular acess was to radial, all patients underwent pre- and post-dilation and angiographic success occurred in all cases. At follow-up there was a significant increase in area (6,41 ± 1,35 mm2 vs. 7,35 ± 1,53 mm2, p < 0,002), volume (101,19 ± 20,9 mm3 vs. 118,51 ± 26,6 mm3, p = 0,001) and diameters of the device, by IVUS, at 6 months when compared to the index procedure. There was no significant change in the areas, volumes and diameters of the vessel and lúmen, in any comparison at follow-up. The late loss was 0,22 ± 0,30 mm at 6 and 0,33 ± 0,44 mm at 18 months. There were no cases of restenosis and scaffold thrombosis. During follow-up there was no case of MACE. CONCLUSIONS: PCI with the use of DESolve scaffold for the treatment of non-complex coronary artery disease has shown promising results. There was an increase in the volume and area of the device at 6 months and an effective suppression of intimal hyperplasia without MACE at follow-up.
53

Percutaneous Endoscopic Gastrostomy Placement Time in People with Cystic Fibrosis

Gunnell, Sarah 01 May 2002 (has links)
A retrospective chart review was conducted on pediatric patients at the Intermountain Cystic Fibrosis Center who had a percutaneous endoscopic gastrostomy (PEG) placed between 1993 and 1999. Height velocity improved significantly in the group of patients with a PEG placed; however, pulmonary function declined more significantly over time. Questionnaires regarding attitude toward PEG placement were sent to patients enrolled in accredited cystic fibrosis centers in the mountain west region and to their parents. The overall response rate was 54.25% for the PEG questionnaire and 24% for the non-PEG questionnaire. Ninety-six percent of the patients with a PEG reported that weight was a problem at time of placement, and 91% reported weight gain after PEG ill placement. Sixty-four percent of the patients with a PEG reported that they would have a PEG placed if they made the decision again. Of the patients without a PEG, 60.7% thought a PEG looked bad, and 59.2% would be embarrassed to have a PEG. Forty-nine percent of patients without a PEG expressed a lack of knowledge of the pros and cons of PEG placement and 35.4% had no opinion about their knowledge of PEGs. PEG placement can be beneficial in improving nutritional status. Optimal time for PEG placement may be earlier rather than after pulmonary function has declined. People with a PEG have felt positive toward placement, and those without a PEG seem to lack knowledge about the pros and cons of PEG placement.
54

Occupational Sharps Injuries in Medical Trainees at the University of South Florida: A Follow-up Study

Starkey, Kourtni L. 23 March 2018 (has links)
Medical trainees (medical students and resident physicians) are at high risk of sharps injury (needlestick injury). High rates of sharps injury in this population and the risk incurred by exposure to bloodborne pathogens poses a threat both to medical trainees who are at risk for bloodborne pathogen exposure and to training institutions for legal and financial reasons. This study examines the prevalence of sharps injuries in medical trainees at the University of South Florida and compares that to data on sharps injuries in US medical trainees. Data from the present study was compared to previously collected USF medical trainee sharps injury data. Results from this study demonstrated that residents had higher rates of sharps injury than medical students. A prior USF study of similar data from academic years 2002-2008 had similar findings. This study demonstrated a peak in sharps injury rate in first year residents, similar to the prior USF study. Resident rates remained highest in Surgery and lowest for Psychiatry and Pediatrics. This information can be used to focus hazard analysis and risk reduction efforts at USF Health. This data can also be combined with the known efficacy of simulated training experience should encourage increased use of USF’s center for advanced medical simulation (CAMLS) to increased procedural experience in medical students and junior residents and decrease their exposure to bloodborne pathogens by increasing knowledge and procedural safety.
55

Infrainguinal Percutaneous Transluminal Angioplasty in Limbs with Severe Lower Limb Ischaemia

Löfberg, Anne-Marie January 2001 (has links)
<p>Infrainguinal bypass grafting is an established method in the treatment of patients with femoropopliteal and crural occlusive disease leading to critical lower limb ischaemia (CLI). However, complications related to surgical procedure are not negligible and percutaneous transluminal angioplasty (PTA) has emerged as an alternative. The present thesis covers some aspects of infrainguinal PTA in patients with chronic severe lower limb ischaemia.</p><p>The records of 217 patients undergoing 272 PTA procedures at various infrainguinal arterial segments were analysed. The indication for intervention was subcritical ischaemia in 76 limbs and critical ischaemia in 177 limbs. The role of duplex ultrasound examination in the selection of patients for PTA was retrospectively evaluated following a prospective validation of the method against angiography.</p><p>A technically successful PTA was achieved in 89%. The overall 30-day mortality was 2.7%. No patient underwent amputation directly related to failed PTA. The primary success rates at 12 and 60 months following femoropopliteal PTA were 40% and 27% compared, to 51% and 36% in limbs undergoing crural artery PTA. Primary success rate in limbs with SFA occlusion longer than 5 cm was only 12% after 5 years, compared to 32% if the occlusion was equal or less than 5 cm in length (p<0.01). In patients undergoing distal PTA through patent infrainguinal grafts, the primary and primary assisted patency rates at 3 years were 32% and 53%, respectively. The sensitivity of duplex scanning in the selection of lesions for PTA was less satisfactory in the popliteal and crural arteries compared to the superficial femoral arteries.</p><p>In conclusion, the results of infrainguinal PTA performed for treatment of subcritical or CLI seemed to be inferior to the results of surgical interventions reported in the literature. However, due to the fact that the PTA procedure does not preclude the performance of bypass grafting, it might be an alternative to surgical intervention in limbs with stenotic or short occlusive lesions.</p>
56

Percutaneous Nephrostomies : Planning for an Optimal Access, Complications, Follow-up and Outcome

Radecka, Eva January 2005 (has links)
<p>Percutaneous nephrostomy (PCN) is a well-established intervention performed to divert urine from the collecting system in ureteric obstruction or as a prelude to interventional procedures such as stent placement or percutaneous nephrolithotripsy (PCNL). The aim of this thesis is to enhance planning for an optimal insertion of PCN, investigate complications, long-term management, follow-up and outcome in patients with PCN treatment and to increase accuracy in CT-guided punctures.</p><p>To enhance planning for an optimal insertion of PCN prior to PCNL, biomodels from CT data were performed. Eight patients with complex urinary calculi were selected. Multislice CT of the kidney was performed and the CT data were transformed into a biomodel. The biomodels visualised unique structures before surgery, which aided the planning of endourological procedures.</p><p>PCNL is an essential procedure for treating complex urinary calculi. A subcostal approach is preferred to avoid laceration to the lung and pleura. However, a supracostal approach is often preferable, as it gives a better passage to the renal pelvis. The nature and frequency of complications after supra- versus subcostal punctures were studied in 85 patients treated with PCNL. In 63 patients, a subcostal track was established. In 22, a supracostal puncture was chosen. The main difference in preoperative complications was the higher number of patients in the supracostal group complaining of respiratory correlated pain (32%). In the subcostal group, this was (5%). </p><p>401 patients were reviewed retrospectively regarding underlying disease, subsequent management and complications of PCN treatment. The number of major complications was 4%. Minor complications were recorded in 38%, urinary tract infection being the most common. 151/401patients suffered from malignancy. 84/151 of the malignant patients died with the catheter. The median survival time of the patients with malignancies was 255 days and the median catheterisation time was 62 days. </p><p>In order to increase accuracy when performing CT guided punctures, a new puncture guide was evaluated. In 15/17 patients the puncture was successful on the first attempt. The benefits of the puncture guide were the artefact from the needle guide pointing at the target indicating the puncture path and the needle support enhancing an accurate puncture.</p>
57

Infrainguinal Percutaneous Transluminal Angioplasty in Limbs with Severe Lower Limb Ischaemia

Löfberg, Anne-Marie January 2001 (has links)
Infrainguinal bypass grafting is an established method in the treatment of patients with femoropopliteal and crural occlusive disease leading to critical lower limb ischaemia (CLI). However, complications related to surgical procedure are not negligible and percutaneous transluminal angioplasty (PTA) has emerged as an alternative. The present thesis covers some aspects of infrainguinal PTA in patients with chronic severe lower limb ischaemia. The records of 217 patients undergoing 272 PTA procedures at various infrainguinal arterial segments were analysed. The indication for intervention was subcritical ischaemia in 76 limbs and critical ischaemia in 177 limbs. The role of duplex ultrasound examination in the selection of patients for PTA was retrospectively evaluated following a prospective validation of the method against angiography. A technically successful PTA was achieved in 89%. The overall 30-day mortality was 2.7%. No patient underwent amputation directly related to failed PTA. The primary success rates at 12 and 60 months following femoropopliteal PTA were 40% and 27% compared, to 51% and 36% in limbs undergoing crural artery PTA. Primary success rate in limbs with SFA occlusion longer than 5 cm was only 12% after 5 years, compared to 32% if the occlusion was equal or less than 5 cm in length (p&lt;0.01). In patients undergoing distal PTA through patent infrainguinal grafts, the primary and primary assisted patency rates at 3 years were 32% and 53%, respectively. The sensitivity of duplex scanning in the selection of lesions for PTA was less satisfactory in the popliteal and crural arteries compared to the superficial femoral arteries. In conclusion, the results of infrainguinal PTA performed for treatment of subcritical or CLI seemed to be inferior to the results of surgical interventions reported in the literature. However, due to the fact that the PTA procedure does not preclude the performance of bypass grafting, it might be an alternative to surgical intervention in limbs with stenotic or short occlusive lesions.
58

Percutaneous Nephrostomies : Planning for an Optimal Access, Complications, Follow-up and Outcome

Radecka, Eva January 2005 (has links)
Percutaneous nephrostomy (PCN) is a well-established intervention performed to divert urine from the collecting system in ureteric obstruction or as a prelude to interventional procedures such as stent placement or percutaneous nephrolithotripsy (PCNL). The aim of this thesis is to enhance planning for an optimal insertion of PCN, investigate complications, long-term management, follow-up and outcome in patients with PCN treatment and to increase accuracy in CT-guided punctures. To enhance planning for an optimal insertion of PCN prior to PCNL, biomodels from CT data were performed. Eight patients with complex urinary calculi were selected. Multislice CT of the kidney was performed and the CT data were transformed into a biomodel. The biomodels visualised unique structures before surgery, which aided the planning of endourological procedures. PCNL is an essential procedure for treating complex urinary calculi. A subcostal approach is preferred to avoid laceration to the lung and pleura. However, a supracostal approach is often preferable, as it gives a better passage to the renal pelvis. The nature and frequency of complications after supra- versus subcostal punctures were studied in 85 patients treated with PCNL. In 63 patients, a subcostal track was established. In 22, a supracostal puncture was chosen. The main difference in preoperative complications was the higher number of patients in the supracostal group complaining of respiratory correlated pain (32%). In the subcostal group, this was (5%). 401 patients were reviewed retrospectively regarding underlying disease, subsequent management and complications of PCN treatment. The number of major complications was 4%. Minor complications were recorded in 38%, urinary tract infection being the most common. 151/401patients suffered from malignancy. 84/151 of the malignant patients died with the catheter. The median survival time of the patients with malignancies was 255 days and the median catheterisation time was 62 days. In order to increase accuracy when performing CT guided punctures, a new puncture guide was evaluated. In 15/17 patients the puncture was successful on the first attempt. The benefits of the puncture guide were the artefact from the needle guide pointing at the target indicating the puncture path and the needle support enhancing an accurate puncture.
59

Magnetic Resonance Elastography for Measuring the Compliance of Chronic Total Occlusions

Kates, Brian S. 12 December 2011 (has links)
Percutaneous coronary revascularization of chronic total occlusions (CTOs) is difficult due to the presence of a hard proximal fibrous cap and lack of image guidance. The use of x-ray fluoroscopy alone makes it difficult to identify vessel boundaries and occlusive constituents which would aid the process of revascularization. It also can be difficult to keep a guidewire intraluminal without puncturing the vessel wall. Although several imaging modalities are being developed, a technique for measuring the stiffness of occlusions would facilitate revascularization by helping the process of guidewire selection and placement. In this study, a technique known as static magnetic resonance elastography is explored as a method of determining the compliance of CTOs. A finite element simulation was used to determine the response of an artery to deformation, and displacement images were obtained from an artery phantom using a stimulated echo MR imaging pulse sequence and a pneumatic compression system.
60

Magnetic Resonance Elastography for Measuring the Compliance of Chronic Total Occlusions

Kates, Brian S. 12 December 2011 (has links)
Percutaneous coronary revascularization of chronic total occlusions (CTOs) is difficult due to the presence of a hard proximal fibrous cap and lack of image guidance. The use of x-ray fluoroscopy alone makes it difficult to identify vessel boundaries and occlusive constituents which would aid the process of revascularization. It also can be difficult to keep a guidewire intraluminal without puncturing the vessel wall. Although several imaging modalities are being developed, a technique for measuring the stiffness of occlusions would facilitate revascularization by helping the process of guidewire selection and placement. In this study, a technique known as static magnetic resonance elastography is explored as a method of determining the compliance of CTOs. A finite element simulation was used to determine the response of an artery to deformation, and displacement images were obtained from an artery phantom using a stimulated echo MR imaging pulse sequence and a pneumatic compression system.

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