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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.
11

Percutaneous delivery of methotrexate in the absence and presence of natural permeation enhancers / Mariska H. Pretorius

Pretorius, Mariska Heleen January 2003 (has links)
The transdermal delivery of drugs has a lot of advantages above other routes of delivery, such as the avoidance of first-pass hepatic and intestinal metabolism, the non-invasive infusion of drugs, etc. However, the transdermal delivery of drugs, especially hydrophilic drugs, is limited due to the lipophilic nature of the stratum corneum. Methotrexate is a folic acid antagonist with antineoplastic activity and is used for the treatment of psoriasis and Kaposi's sarcoma. The permeation of methotrexate through the skin for systemic use is however limited due to its high molecular weight, the fact that it is mainty dissociated at physiological pH and its hydrophilic nature (Alvarez-Figueroa et al.. 2001). Thus the aim of my study was to enhance the permeation of methotrexate with the use of terpene. Terpenes are lipophilic in nature and have Log P values of around 2-4 (Godwin & Michniak, 1999). These characteristics make them excellent candidates as penetration enhancers. Terpenes are not only used for penetration enhancers, but in a huge number of other products, such as aromatherapeutic oils. For this reason the permeation of the terpenes through human skin and the effect of methotrexate on this permeation were also determined. The following enhancers were used in this study: menthol, menthone. isomenthol, limonene, B-myrcene, a-pinene and 1,8-cineole Five different sets of experiments were done in this study: a) a control experiment with methotrexate in the absence of the terpenes without ethanol; b) a control experiment with methotrexate in the absence of the terpenes with ethanol: c) experiments with methotrexate in the presence of the terpenes; d) control experiments with the terpenes in the absence of methotrexate and e) experiments with tile terpenes in the presence of methotrexate. For this study only human female abdominal skin was used. A saturated solution of methotrexate in water:propylene glycol (50:50) with a pH between 4 and 5 (Vaidyanathan et al., 1985) was used as the model drug and the receptor phase was PBS-buffer (pH=74) and water:ethanol (50:50) for HPLC and GC analysis respectively. The dilfusion apparatus used consisted of Vertical Franz diffusion cells with a capacity of 2 ml and a diffusion area of 1.075 cm2. The cells were placed in a water bath (+- 37 "C) on magnetic stirrers for the duration of the experiment. After the receptor phase was placed in the receptor compartment the cells were equilibrated for an hour before putting 25 ul of a 5% terpene solution in absolute ethanol on the skin in the donor compartment. This was left for half and hour to allow evaporation of the ethanol. The saturated solution of the methotrexate was now placed on the skin in the donor compartment. The experiments for methotrexate stretched over a period of 12 hours and samples were collected every 2 hours. The terpene experiments were performed over a 24-hour period and samples were taken at 2,4,6,12 and 24 hours. The concentration methotrexate permeated was determined by using HPLC-analysis and terpenes by using GC-analysis. The flux (ug/cm2/h), kp(cm/h), lag time (h) and enhancement ratio were calculated to compare the methotrexate permeation in the control and actual experiments. The results showed that a-pinene, B-myrcene and isomenthol enhanced the permeation of methotrexate most, although all the terpenes had an enhancing effect. They produced a 4- fold increase in the flux values of methotrexate. Due to the fact that the terpene experiments were only a semi-quantitative evaluation only the percentage terpenes that permeated was calculated. The experiments were done on all the terpenes except apinene. All the terpenes permeated the skin with menthol having the highest permeation. The results also showed that methotrexate did have an effect on the terpene permeation. Menthone and menthol's permeation was higher in the presence of methotrexate, while the other terpenes had a higher permeation in the absence of methotrexate. The reason for this is not clear. In conclusion, the study revealed that the enhancers used did have an enhancing effect on methotrexate permeation. This could be due to the extraction or disruption of lipids by the terpenes (Zhoa & Singh, 2000) or an increase in diffusivity and partitioning. The terpene experiments also showed that the terpenes do permeate the skin and that methotrexate does have an effect on this permeation. / Thesis (M.Sc.)--North-West University, Potchefstroom Campus, 2004.
12

Periprocedural myocardial infarction following percutaneous coronary intervention at Charlotte Maxeke Johannesburg Academic Hospital

Tsabedze, Nqoba Israel January 2017 (has links)
Original published work submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Medicine (Internal Medicine) 18 October, 2017. / The very first coronary artery balloon angioplasty is reported to have been performed by Gruntzig in 1977.1 Subsequently to this, over the past 40 years, there have been significant advances in coronary angiography and intervention. Coronary artery interventional techniques have evolved and improved significantly. There have been considerable device developments, new generation stents and novel antiplatelet therapy which have all proved to reduce the incidence of the primary periprocedural complications associated with percutaneous coronary intervention (PCI). [No abstract provided. Information taken from introduction] / LG2018
13

A novel encapsulation favorably modifies the skin disposition of topically-applied N,N-diethyl-3-methylbenzamide (DEET)

Karr, Jennifer I. January 2012 (has links)
No description available.
14

MATHEMATICAL MODEL FOR PREDICTING THE PERCUTANEOUS ABSORPTION OF FRANGRANCE RAW MATERIALS

SAIYASOMBATI, PENPAN 02 September 2003 (has links)
No description available.
15

MATHEMATICAL MODEL TO PREDICT THE SKIN DISPOSITION OF DEET AND OTHER VOLATILE COMPOUNDS

SANTHANAM, ARJUN 05 October 2004 (has links)
No description available.
16

Ribonucleotide Reductase Inhibitors for Restenosis

Mutchler, Megan Marie 21 August 2008 (has links)
No description available.
17

Abdominal aortic peripheral intervention to facilitate intra-aortic balloon pump support during high risk percutaneous coronary intervention: a case report

Low, See W, Lee, Justin Z, Lee, Kwan S 10 March 2015 (has links)
UA Open Access Publishing Fund / Background: The use of intra-aortic balloon pump (IABP) via the trans-femoral approach has been established for hemodynamic support in patients undergoing high-risk percutaneous coronary intervention (PCI). However, there are various challenges associated with its use, especially in patients with aortoiliac occlusive arterial disease. Case presentation: We describe a case of high-risk PCI with IABP support complicated by intra-procedural detection of severe abdominal aortic stenosis that was successfully overcome with angioplasty of the stenotic lesion. Conclusions: Our report highlights distal abdominal aortic stenosis as a potential barrier to successful PCI with IABP support, and angioplasty as an effective means to overcome it.
18

Angioplastia transluminal percutânea: contribuição ao tratamento da hipertensão arterial renovascular e da nefropatia isquêmica / Percutaneous transluminal angioplasty: contribution to the treatment of renovascular hypertension and nephropathy ischemic

Martins, Valéria Marcia 22 March 2004 (has links)
As lesões estenóticas ou oclusivas das artérias renais podem levar à isquemia do parênquima renal com conseqüente hipertensão arterial (hipertensão arterial renovascular) e perda de função renal (nefropatia isquêmica). Estas duas entidades podem ser tratadas por medicamentos, cirurgia ou angioplastia transluminal percutânea. O objetivo deste trabalho foi avaliar o sucesso técnico e funcional da angioplastia em lesões estenóticas ou oclusivas das artérias renais em doentes portadores de hipertensão arterial renovascular e nefropatia isquêmica. Tratamos 131 doentes hipertensos com ou sem alteração da função renal (55 do sexo masculino e 76 feminino), que apresentavam 191 artérias renais comprometidas (148 estenoses e 43 oclusões) e com média de idade de 45,83 ± 17,4 anos (4 a 77 anos). A etiologia da lesão da artéria renal foi a aterosclerose em 65 doentes (49,61%), displasia fibromuscular em 41 (31,29%), arterite de Takayasu em 13 (9,92%) e outras causas em 12 (9,16%). O nível sérico de creatinina era normal em 70 (53,43%) e alterado em 61 (46,58%). O sucesso técnico foi obtido em 93 doentes (70,99%) e em 123 artérias renais (75,46%). O seguimento foi, em média, de quatro anos (2 a 8 anos), sendo que ao final deste período houve redução de 37,80 ± 33,46 mmHg e 28,66 ± 24,74 mmHg nos níveis da PA sistólica e diastólica, respectivamente. Houve cura da hipertensão arterial em nove doentes (11,25%), melhora em 59 (73,75%), permaneceu inalterada em oito (10%) e piorou em quatro (5%). A função renal ficou normal em 36 doentes (45%), melhorou em 11 (13,75%), manteve-se em 26 (32,5%) e piorou em sete (8,75%). Houve recidiva em 14 casos (17,5%), sendo 11 casos (78,57%) tratados com sucesso com nova angioplastia. Conclusão: consideramos que a angioplastia transluminal percutânea pode ser indicada como opção para o tratamento das lesões estenóticas e/ou oclusivas das artérias renais nos doentes com hipertensão renovascular e nefropatia isquêmica / The occlusive and stenotic lesions of the renal arteries can lead to a renal parenchyma ischemia with vascular hypertension resultant (reno vascular hypertension) and loss of renal function (nephropathy ischemic). These two conditions can be treated by medications, surgery or Percutaneous Transluminal Angioplasty (PTA). The objective of this work was assessing the technical and functional success of PTA in stenotic or occlusive lesions of renal arteries in patients having renovascular hypertension and nephropathy ischemic. We treated 131 hypertensive ill people with or without alteration in the renal function (55 males and 76 females) who presented 191 damaged renal arteries (148 stenosis and 43 occlusions) and age range of 45.83+ 17.4 years old (4 to 77 years old). The etiology of the lesion in the renal artery was atherosclerosis in 65 ill people (49.61%), fibro muscular dysplasia in 41 (31.29%), Takayasu\'s disease in 13 (9.92%), and other causes in 12 (9.16%). The plasma creatinine level was normal in 70 (53.43%) and altered in 61 (46.58%). The technical success was obtained in 93 ill people (70.99%) and in 123 renal arteries (75.46%). The follow-up lasted in average for 4 years (2 to 8 years), in which the end of the period there was a decrease of 37.80+33.46 mmHg and 28.66+24.74 mmHg in the systolic and diastolic blood pressure levels respectively. There was a cure of artery hypertension in 9 ill people (11.25%), better results in 59 (73.75%), no alteration in 8 (10%) and worsening in 4 (5%). The plasma creatinine level increased in 10% (SD), although the renal function remained normal in 36 ill people (45%), better in 11 (13.75%), remained the same in 26 (32.5%) and got worse in 7 (8.75%). There was a reoccurrence in 14 cases (17.5%), in which 11 cases (78.57%) were treated successfully with new PTA. Conclusion: it was considered that PTA can be indicated as an option for the treatment of stenotic and occlusive lesions of the renal arteries in ill people with renovascular hypertension and nephropathy ischemic
19

"Acesso percutâneo lateral no tratamento da litíase renal" / Side percutaneous access in the renal lithiases treatment

Chedid Neto, Elias Assad 23 September 2005 (has links)
A nefrolitotripsia percutânea (NP) é uma das principais formas de tratamento de cálculos renais volumosos. O acesso percutâneo lateral é feito com o paciente em decúbito dorsal horizontal. O estudo objetivou avaliar os resultados de acesso lateral, em posição modificada, no tratamento percutâneo de cálculos renais e também o mesmo associado ao ureteroscópico, em caso de cálculos renais e ureterais concomitantes. Estudou-se 88 pacientes e os resultados foram considerados bem sucedidos em 69,32%. As complicações mais comuns foram febre e sangramento. Concluímos que a NP com acesso lateral apresenta sucesso no tratamento da litíase oferecendo vantagens no posicionamento para realização de procedimento associado à ureteroscopia / Percutaneous nephrolithotripsy (PN) is one of the main alternatives for the treatment of large renal stones. The present study aimed to evoluate the results of the lateral percutaneous approach, in a modified position, for the treatment of kidney stones. We also evaluated the association of the percutaneous with the uretroscopic treatment in patients with concomitant kidney and ureteral stones. A total of 88 patients selected, 69,32% of patients were considered complete success. The most common complication was the development fever and bleeding. In conclusion the PN using the lateral approach is a safe procedure with a high success rate in the treatment of kidney stones and is a advantageous, for patient positioning especially for the performance of ureteroscopic procedures
20

An Evidence-Based Approach to Percutaneous Coronary Intervention Access

Sanni, Kemi Funlayo 01 January 2018 (has links)
Coronary heart disease is a significant cause of mortality and morbidity in the United States; Healthy People 2020 set an objective to reduce the rate of the disease by 20% to the baseline rate of 126 deaths per 100,000 population per year. In the local healthcare setting, heart disease was responsible for a high percentage of mortality and morbidity. To address this, the local site developed a plan to improve outcomes for patients seeking care at the facility. Because the femoral approach to percutaneous coronary intervention (PCI) was used to treat coronary heart conditions at the site and complications were frequent, a quality improvement initiative was begun that included a shift to the use of radial artery PCI. The purpose of this project was to evaluate whether the new approach lowered the complication rates. The project focused question asked how the complication rate of transradial and transfemoral approach to PCI compared. Data from nonrandom aggregate PCI results for 158 adult patients, ages 40-80 years; data from the National Cardiovascular Data Registry; and summarized unit reports were used to compare the transfemoral and transradial outcomes. Two-samples t test results indicated the complications were clinically and significantly lower (p < .01) with patients who underwent the transradial approach (n = 82) compared to those who had the transfemoral approach (n = 76). Study results suggest the new initiative using the transradial approach for PCI reduced the complications for patients undergoing PCI at the site. Positive social change is possible as the morbidity and mortality rates were reduced and consumers who need the procedure may experience a lower burden of physical and fiscal cost.

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