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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.
91

Evaluating the Implementation and Results of EU 2017/745 / Att utvärdera implementeringen och resultaten av EU 2017/745

Gustafsson, Olivia January 2022 (has links)
The new regulation on medical devices, EU 2017/745, came into force in May 2021 meaning that all economic operators in the industry need to adhere to new, stricter requirements. As there is yet no common practice on how to implement and comply with the new requirements, many struggles with this.  In this thesis, the implementation of a distributor company operating in the medical device industry, currently in the middle of the implementation, is qualitatively evaluated to identify areas of improvement. This is done by conducting a case study where the company's implementation approach is mapped and evaluated with regard to good practice, and implemented organizational changes due to the regulation are identified and benchmarked against similar companies. Their interpretation and implementation appear to be rather strict and ambitious based on the overviewing benchmark with similar distributors. Their implementation moreover largely followed good practice, but several areas of improvement could nevertheless be identified.  Additionally, this thesis aimed to explore how the result of the final implementation of EU 2017/745 can be assessed. A literature review was conducted where general parameters to assess regulatory implementation were identified, followed by a literature review where it was investigated how these parameters can be adapted to assess the result of the implementation of EU 2017/745. Several parameters of interest to assess the result were identified together with examples of indicators that can be used. More research is however needed to be able to establish a complete, adequate method to assess the final implementation result. / Den nya förordningen för medicintekniska produkter, EU 2017/745, trädde i full kraft i maj 2021. Det betyder att alla ekonomiska aktörer verksamma i den medicintekniska industrin måste anpassa sig till nya, hårdare krav. Många upplever dock svårigheter eftersom det ännu inte finns någon praxis för hur kraven ska implementeras och efterlevas. I den här uppsatsen genomförs en kvalitativ utvärdering av implementeringen hos en medicinteknisk distributör som befinner sig mitt i implementeringsarbetet, för att identifiera förbättringsmöjligheter. Detta görs genom en case study, där företagets implementering kartläggs och utvärderas i relation till good practice. Vidare identifieras organisatoriska förändringar som genomförts som en följd av förordningen, och benchmarkas mot andra, liknande företag. Utvärderingen visade att företagets tolkning och implementeringen av kraven stod sig väl i relation till det övergripande benchmark som tillhandahölls. Vidare följde implementeringen i stora drag good practice, men ett antal förbättringsmöjligheter kunde ändå identifieras.  Vidare syftar uppsatsen till att utforska hur resultatet av implementeringen av EU 2017/745 kan bedömas när implementeringen är färdig. En literaturstudie på allmän regulatorisk utvärdering samt organisatorisk förändringsutvärdering genomfördes, där områden relevanta för att utvärdera regulatorisk implementering identifierades. Detta följdes av en vidare literaturstudie för att undersöka hur dessa områden kan anpassas för bedöma resultatet av EU 2017/745. Ett antal intressanta områden tillsammans med exempel på indikatorer som kan användas för en sådan bedömning identifierades. Vidare arbete behövs dock för att fastställa en heltäckande, ändamålsenlig metod för att bedöma implementeringsresultatet.
92

The Medical Device Regulation : What Impact Will the New Regulation Have on the Medical Device Industry and How Will Companies Use Standards to Meet the New Requirements / Förordningen om medicintekniska produkter : Vilken inverkan kommer förordningen ha på den medicintekniska industrin och hur kommer företag att använda standarder för att uppfylla de nya kraven

Thunborg, Emelie, Österberg, Emma January 2021 (has links)
The New Medical Device Regulations (MDR) will become affective on 26 May, 2021. The new regulation entails higher requirements for companies that develop medical devices, but also for all parties involved in the medical device industry. The strengthened requirements mean that it will be more difficult to meet all the criteria for placing medical devices on the market. This thesis has been carried out on behalf of the Swedish Institute for Standards (SIS) and examines companies' transition to MDR and how companies can get support from SIS, but also by other organizations and authorities. A qualitative literature study and document study has been carried out to ponder interview questions, which have then been answered by companies, authorities and organizations who are in one way or another affected by the transition to MDR. Part of the work was also to find out how the companies, depending on size, differ from each other to comply with the new regulation. The results showed that the transition to MDR differs significantly between all the interviewed parties, but that everyone agrees that standardization is important. / Den nya förordningen om medicintekniska produkter (MDR) kommer att träda i kraft den 26 maj, 2021. Den nya förordningen innebär högre krav på företag som utvecklar medicintekniska produkter, men även på alla inblandade parter i den medicintekniska industrin. De stärkta kraven innebär att det kommer vara svårare att uppfylla alla kriterier för att kunna placera medicintekniska produkter på marknaden. Detta examensarbete har utförts på uppdrag av Svenska Institutet för Standarder (SIS) och undersöker företagens övergång till MDR och hur företag kan få stöd, bland annat av SIS, men också av andra organisationer och myndigheter. Det har genomförts en kvalitativ litteraturstudie och dokumentstudie för att formulera intervjufrågor som sedan har besvarats av företag, myndigheter och organisationer som på ett eller annat sätt blir påverkade vid övergången till MDR. En del av arbetet var även att ta reda på hur företagen, beroende på storlek, skiljer sig mellan varandra vad gälleratt uppfylla det nya regelverket. Resultatet visade att övergången till MDR skiljer sig markant mellan alla de intervjuade parterna, men att alla är eniga om att standardisering är viktigt.
93

Hearing function in adults with Multiple Drug Resistant-TB : a retrospective review.

Kavallieratos, Angela 04 September 2012 (has links)
KwaZulu-Natal has been ranked as having the fourth highest incidence of transmitted Multiple Drug Resistant-Tuberculosis (MDR-TB) in sub-Saharan Africa. Substantial literature exists indicating the permanent damage that MDR-TB medication has on hearing abilities. The purpose of this study was to describe the hearing function of adults on long term MDR-TB treatment from Murchison Hospital MDR-TB unit in the Ugu District in rural KwaZulu-Natal. The primary aim of the study was to review the possible changes in hearing function in a group of adults on long-term treatment for MDR-TB. Secondly, the study aimed to estimate the number of adults who may present with changes following MDR-TB treatment and establish if relationships exist between the audiological findings and factors such as age and gender. The design of the study was a retrospective comparative data review of 68 patient records, all of which underwent audiological investigations from the start of MDR-TB treatment over a five-month period. The study made use of descriptive and inferential statistics to analyse the data. Specific inferential statistical analysis included analysis of covariance as well as regression analysis. Results from the study showed changes in hearing function in Distortion Product Otoacoustic Emissions (DPOAEs) and Pure Tone Audiometry (PTA) results at all five audiological sessions and across a range of frequencies. 84% of the total sample presented with overall refer readings for DPOAEs and 98.53% of the group of adults presented with criteria indicative of ototoxic hearing loss, specifically a bilateral mild-profound sloping SNHL on clinical PTA results. In the total sample of patient records reviewed in this study, all 68 records showed a change in hearing function, be that changes in DPOAE function and/or changes in PTA thresholds, following long-term treatment for MDR-TB. Variations in the effects of gender and ear difference were minimal and non-significant in all results. Similar presentation, to ototoxic hearing loss, of other degenerative conditions exists; however these conditions were accounted for as exclusion criteria in this study. Therefore the only remaining cause of possible hearing deficit was that of ototoxicity. The study provided valuable data regarding hearing function in a population of adults on long-term MDR-TB treatment in South Africa. Furthermore, the study has highlighted the need for the establishment of standardised audiological monitoring programmes sensitive to ototoxic hearing loss, within the South African context where the incidence of Tuberculosis (TB) and MDR-TB is reportedly high.
94

Evaluation of novel efflux transport inhibitor for the improvement of drug delivery through epithelial cell monolayer

Sonawane, Amit January 2015 (has links)
Blood-brain barrier (BBB) is a unique membranous barrier, which segregates brain from the circulating blood. It works as a physical and metabolic barrier between the central nervous system (CNS) and periphery. In mammals, endothelial cells were shown to be of BBB and are characterized by the tight junctions along with efflux system which are responsible for the restriction of movement of molecules within the cells. Efflux system consists of multidrug resistance proteins such as P-glycoprotein (P-gp). P-gp removes substances out back from the brain to the blood before they reach to the brain. So the barrier is impermeable to many compounds such as amino acids, ions, small peptides and proteins, making it the most challenging factor for the development of new drugs for targeting CNS. Curcumin is a bioactive compound that has a number of health promoting benefits such as anti-inflammatory, anticancer, anti-oxidant agent; as well as a role in neurodegenerative diseases, but low oral bioavailability is the major limiting factor. Low water solubility and rapid metabolism are the two important factors responsible for poor bioavailability of curcumin. Galaxolide is a musk compound and previously known for the bioaccumulation of toxic components in the aquatic animals by interference with the activity of multidrug/multixenobiotic resistance efflux transporters (MDR/MXR). The bioavailability of curcumin can be enhanced when administered with galaxolide. This study was carried out to investigate the effect of galaxolide on the permeation of curcumin through the epithelial cell monolayers. MDCKII-MDR1 cell monolayer is used an in vitro blood-brain barrier model while Caco-2 monolayer is used as an in vitro intestinal model, which also expresses the P-glycoprotein. The curcumin and galaxolide were separately solubilised in the DMSO and used in combination to perform permeation study, to determine the effect of galaxolide on curcumin permeation through epithelial cell monolayers. The galaxolide shows an efflux protein inhibition activity and this activity was used to enhance permeation of curcumin through the Caco-2 monolayer. In summary, galaxolide is a novel permeation enhancer molecule, which can be used for the improvement of drug delivery of other bioactive compounds in future.
95

Treatment outcomes of patients with MDR-TB and its determinants at referral hospitals in Ethiopia

Mengistu, Kenea Wakjira 01 1900 (has links)
Text in English / Aim: The aims of this study were to investigate the treatment outcomes of patients with MDRTB and its determinants at referral hospitals in Ethiopia. The study also aims to develop a conceptual model for enhancing treatment of patients with MDR-TB in Ethiopia. Design and methods: A concurrent mixed methods design with quantitative dominance was used to investigate treatment outcomes of patients with MDR-TB and its determinants. Results: A total of 136 (n=136) patients with MDR-TB participated in the study, 74 (54%) were male and 62 (46%) were female. Forty-one (31%) of the patients had some co-morbidity with MDR-TB at baseline, and 64% had body mass index less than 18.5kg/m2. Eight (6%) of the patients were diagnosed among household contacts. At 24 months, 76/110 (69%) of the patients had successfully completed treatment, but 30/110 (27%) were died of MDR-TB. Multivariable logistic regression revealed that the odds of unfavourable treatment outcomes were significantly higher among patients with low body mass index (BMI <18.5kg/m2) (AOR=2.734, 95% CI: 1.01-7.395; P<0.048); and those with some co-morbidity with MDR-TB at the baseline (AOR=4.260, 95%CI: 1.607-11.29; p<0.004). The majority of the patients were satisfied with the clinical care they received at hospitals. But as no doctor was exclusively dedicated for the MDR-TB centre, patients could not receive timely medical attention and this was especially the case with those with emergency medical conditions. The caring practice of caregivers at the hospitals was supportive and empathic but it was desperate and alienating at treatment follow up centres. Patients were dissatisfied with the quality and adequacy of the socio-economic support they got from the programme. Despite the high MDR-TB and HIV/AIDS co-infection rate, services for both diseases was not available under one roof. Conclusions: Low body mass index and the presence of any co-morbidity with MDR-TB at the baseline are independent predictors of death among patients with MDR-TB. Poor communication between patients and their caregivers and inadequate socio-economic support were found to determine patients’ perceived quality of care and patients’ satisfaction with care given for MDR-TB. / Health Studies / D. Litt et Phil. (Health Studies)
96

Metastatic Behaviour Of Doxorubicin Resistant Mcf-7 Breast Cancer Cells After Vimentin Silencing

Tezcan, Okan 01 January 2013 (has links) (PDF)
Chemotherapy is one of the common treatments in cancer therapy. The effectiveness of chemotherapy is limited by several factors one of which is the emergence of multidrug resistance (MDR). MDR is caused by the activity of diverse ATP binding cassette (ABC) transporters that pump drugs out of the cells. There are several drugs which have been used in treatment of cancer. One of them is doxorubicin that intercalates and inhibits DNA replication. However, doxorubicin has been found to cause development of MDR in tumors. It has been reported that there is a correlation between multidrug resistance and invasiveness of cancer cells. Vimentin is a type III intermediate filament protein that is expressed frequently in epithelial carcinomas correlating with invasiveness and also poor prognosis of cancer. There are several studies that have shown the connection between expression level of vimentin and invasiveness. In this study, MCF-7 cell line (MCF-7/S), which is a model cell line for human mammary carcinoma, and doxorubicin resistant MCF-7 cell line (MCF-7/Dox) were used. The resistant cell line was previously obtained by stepwise selection in our laboratory. The main purpose of this study was to investigate changes of metastatic behaviour in MCF-7/Dox cell line, after transient silencing of vimentin gene by siRNA. In conclusion, down-regulation of vimentin gene expression in MCF-7/Dox cell lines was expected to change the characteristics in migration and invasiveness shown by migration and invasion assays.
97

Molecular Mechanisms Of Vincristine And Paclitaxel Resistance In Mcf-7 Cell Line

Demirel Kars, Meltem 01 December 2008 (has links) (PDF)
Resistance to broad spectrum of chemotherapeutic agents in cancer cell lines and tumors has been called multiple drug resistance (MDR). In this study, the molecular mechanisms of resistance to two anticancer agents (paclitaxel and vincristine) in mammary carcinoma cell line MCF-7 were investigated. MCF-7 cells were selected in the presence of paclitaxel and vincristine by stepwise dose increments. The cell viability and growth profiles of resistant sublines were examined. As the resistance indices increased, the growth rates of sublines were found to decrease. Gene and protein expression levels of the basic drug resistance proteins P-gp and MRP1 were studied in sensitive and drug resistant MCF-7 cells. It was shown that P-gp overexpression is significantly contributing to the developed drug resistance phenotype. Mutation analysis of beta tubulin gene which encodes the target of paclitaxel and vincristine was performed. Single histidine to proline mutation was identified near GTP binding site of beta tubulin in vincristine resistant subline which was not reported before. Apoptosis related BCL-2 and BAX were examined at both gene and protein expression levels and they were not found to be significantly related to the developed resistance in the sublines. The reversal of drug resistance by various inhibitory agents of P-gp and MRP1 was investigated by using flow cytometry. Synthetic silicon compounds were found to be the most effective MDR reversal agents. The effects of various combinations of anticancer drugs and reversal agents on cell proliferation were examined by checkerboard microplate method. ALIS409-paclitaxel and paclitaxel-doxorubicin pairs seem to have highest antiproliferative effects on resistant sublines. The microarray expression profiling of sensitive and resistant MCF-7 cells was performed for a much detailed and comprehensive analysis of drug resistance. The results indicated that the upregulation of MDR1 gene is the dominating mechanism of paclitaxel and vincristine drug resistance. Additionally up regulation of the genes encoding the detoxifying enzymes (i.e. GSTP1) was observed. Significant down regulation of apoptotic genes (i.e. PDCD2/4/6/8) and alterations in expression levels of genes related to invasion and metastasis (MMPs, ADAMs, COL4A2, LAMA etc.) were detected. Upregulation of some oncogenes (i.e. ETS, RAS) and cell cycle regulatory genes (CDKN2A, CCNA2 etc.) was seen which may be in close relation to MDR in breast cancer. Further studies will demonstrate the relationship between the components contributing to drug resistance phenotype in breast cancer cells.
98

Antimicrobial Nanoparticles: A Green and Novel Approach for Enhancing Bactericidal Efficacy of Commercial Antibiotics

Shah, Monic 01 August 2014 (has links)
On the verge of entering the post-antibiotic era, numerous efforts are in place to regain the waning charm of antibiotics which are proving ineffective against most “Superbugs”. Engineered nanomaterials, especially gold nanoparticles (GNPs) capped with antibacterial agents, are proving to be an effective and novel strategy against multidrug resistant (MDR) bacteria. In this study, we report a one-step synthesis of antibioticcapped GNPs (25 ± 5 nm) utilizing the combined reducing and capping ability of a cephalosporin antibiotic, ceftazidime. No signs of aggregation or leaching of ceftazidime from GNP surface was observed upon its storage. Antibacterial testing showed dosedependent broad spectrum activity of Cef-GNPs against both Gram-positive (S. bovis and E. durans) and Gram-negative (P. aeruginosa and E. aerogenes) bacteria. A significant reduction in the minimum inhibition concentration (MIC) of Cef-GNPs was observed as compared to the ceftazidime by itself against Gram-negative bacteria. The MIC of Cef- GNPs were 0.1 mg mL-1 (P. aeruginosa and E. aerogenes) and 1.2 mg mL-1 (E. durans and S. bovis). Cef-GNPs exerted bactericidal action on both P. aeruginosa and E. durans by disrupting the cellular membrane resulting in leakage of cytoplasmic content and death of bacterial cell. Our investigation and results provides an additional step in the development of antibiotic capped GNP as potent next generation antibacterial agents.
99

Expression of multidrug resistance genes and proteins and effect of selenite in anthracycline-resistant human tumor cell lines /

Jönsson Videsäter, Kerstin, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.
100

Análise das Bases Moleculares da Resistência à Isoniazida e Rifampicina em Cepas Obtidas de Pacientes com Tuberculose no Estado de Goiás / Analysis of the molecular basis of resistance to isonizid and rifampicin in Mycobacterium tuberculosis isolates abtained from patients with tuberculosis the state of Goias

ALVES, Sueli Lemes de ávila 11 March 2010 (has links)
Made available in DSpace on 2014-07-29T15:30:37Z (GMT). No. of bitstreams: 1 Dissertacao_sueli.pdf: 1117407 bytes, checksum: d50c0b1dad4e594bc8cd5d3880aadcab (MD5) Previous issue date: 2010-03-11 / Multidrug-resistant tuberculosis is a challenge worldwide. Rapid diagnosis by molecular techniques can provide a more aggressive and appropriate initial therapy. This study aimed to analyze the molecular basis of resistance to isoniazid (INH) and rifampin (R) of Mycobacterium tuberculosis strains isolated from cases of human tuberculosis in Goiás and to genetically determine the causes of the observed resistances. Of the 4.607 cultures for mycobacteria processed in the period of September of 2005 and December of 2007, 24 isolates from 16 patients resistant to at least H and/or R were analyzed. We compared the results obtained by phenotypic tests with mutations in key genes responsible for the development of resistance to these drugs, the rpoB gene for isolates resistant to R and katG gene for strains resistant to H. Seventy one percent of the isolates were resistant to H, and the mutations involved with resistance observed in the katG gene were in codon 315 (41%). The most frequent mutations observed in the rpoB gene of the R resistant isolates (71%) were in codons 456 (76.5%) and 451 (17.6%). Our findings are similar to those reported in the literature. We conclude that the percentage of agreement between genotypic and phenotypic tests was 41% for H and 94% for R considering the number of isolates and 40% and 91%, respectively considering the number of patients. / A tuberculose multidroga resistente representa um desafio em escala mundial. O diagnóstico rápido através de técnicas moleculares é capaz de proporcionar uma terapêutica inicial mais agressiva e adequada. Este trabalho teve como objetivo analisar as bases moleculares da resistência à isoniazida (H) e rifampicina (R) de cepas de Mycobacterium tuberculosis isoladas de casos de tuberculose em Goiás e determinar geneticamente as causas destas resistências. Do total de 4.607 culturas para micobactérias realizadas no período de setembro 2005 a dezembro de 2007, foram analisados 24 isolados de 16 pacientes resistentes a H e/ou R. Os resultados obtidos dos testes fenotípicos de sensibilidade aos antimicrobianos foram comparados às mutações observadas nos principais genes responsáveis pelo desenvolvimento de resistência a estas drogas, gene rpoB para isolados resistentes à R e gene katG para os isolados resistentes à H. Dentre os 24 isolados, 71% eram fenotípicamente resistentes a H e as únicas mutações envolvidas com resistência foram observadas no códon 315 (41%). Dos isolados resistentes a R (71%), foram observadas mutações nos códons 456 (76,5%), 451 (17,6%) e 447 (5,9%). Nossos achados estão em concordância com as principais mutações observadas nos isolados resistentes a R e/ou H descritos na literatura. O percentual de concordância entre os testes fenotípicos e genotípicos foi de 41% para H e 94% para R considerando o número de isolados e de 40% e 91% respectivamente considerando-se o número de pacientes.

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