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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.
351

Livet efter en njurtransplantation : En litteraturöversikt / Life after a kidney transplantation : A literature review

Altarabishi Almuslimani, Emelie, Humphreys, Maria January 2018 (has links)
In Sweden there is 300,000–400,000 people with impaired kidney function. with chronic renal failure, patients experience a limited life, with many symptoms affecting their ways negative and dialysis treatment is time consuming and adversely affects their everyday lives. Kidney transplantation is an effective treatment and is the most common organ transplant in Sweden. Patients hope to have an improved quality of life through a kidney transplant despite the risks of transplant rejection. In order for the nurse to be able to provide good nursing after a kidney transplant and to see what the patient has for nursing needs, the nurses then needs a deeper knowledge of patients' experiences of life after a renal transplant. The aim was to describe how patients experience life after a kidney transplantation. Literature overview based on 10 scientific articles from the database Cinahl Complete, Academic Search Complete and Nursing & Allied Health. The articles are reviewed and analyzed according to Friberg's (2012) method of identifying similarities and differences, then compiled. Following the analyses, three main themes were identified: New life with changes, the experience of limited life, anxiety, concern and loneliness, which describes how life after kidney plantation is experienced by the patient The method discussion is based on the strengths and weaknesses of the literature review. The result is discussed based on Calista Roy's adaptation theory from the key concepts and adaptive features.
352

Reevaluating fecal microbiota transplantation for recurrent clostridium difficile infection

Hamilton, Mariah 24 October 2018 (has links)
Clostridium difficile infection (CDI) is a disease associated with the wide-spread use of antibiotics and causes 450,000 infections and almost 30,000 deaths in the United States annually. Recurrence is a major problem, with approximately 1/3rd of patients relapsing after antibiotic treatment for CDI. Fecal Microbiota Transplantation (FMT) has emerged as a novel therapy for recurrent CDI, but the majority of the literature to date is made up of uncontrolled case series, so FMT’s true efficacy compared with standard antibiotic regimens remains unknown. Only a few randomized control trials (RCTs) have been published, and these have studied small numbers of patients and exhibited marked methodological heterogeneity. As such, there is uncertainty about the appropriate indications for FMT with respect to recurrent CDI, as well as the best methodology for the procedure, which has been carried our using various fecal preparations and modes of delivery. In particular, questions remain about if FMT should be recommended for patients with a first CDI recurrence, and if minimally invasive methods of performing FMT such as administration of enteric coated capsules are more efficacious than standard antibiotic treatments. We propose a double blind, placebo controlled, RCT that will be run as two parallel RCTs, where Trial 1 will enroll patients experiencing a first CDI recurrence, and Trial 2 will enroll patients experiencing a second or later CDI recurrence. The treatment arms in each trial will receive FMT in the form of orally administered frozen capsules, while the control arms will receive standard antibiotic treatments based on the number of recurrences they have experienced. If shown to be efficacious in a large RCT, oral capsulized FMT alone as treatment for recurrent CDI has the potential to increase access to FMT, decrease unnecessary antibiotic use, and substantially reduce morbidity and mortality attributable to CDI.
353

Effects of Hand Transplantation on Cortical Organization

Bogdanov, Sergei, Bogdanov, Sergei January 2012 (has links)
Amputation induces substantial reorganization of the body part somatotopy in primary sensory cortex (S1), and these effects of deafferentation increase with time. Determining whether these changes are reversible is critical for understanding the potential to recover from deafferenting injuries. Here, we report evidence that the representation of a transplanted hand and digits can actually recapture the pre-amputation S1 hand territory in two transplant patients. With limited sensation 4 months post operation, one of the patient's (D.S.) palmar tactile stimulation evoked contralateral S1 responses that were indistinguishable in location and amplitude from those detected in healthy matched controls. The other patient (M.S.) demonstrated not only much improved sensation but also recovered ability to localize tactile stimuli 120+ months after the operation. The results described suggest that even decades after complete deafferentation, restoring afferent input to S1 leads to re-establishment of the gross hand and digits representations within their original territory. Stimulation of the deafferented cortical maps may play an important role in maintaining their viability until the afferent input is restored. Motor imagery and creation of virtual visual feedback of the absent hand with a mirror have been proposed as stimuli. We used fMRI to record neural activity while 11 unilateral hand amputees and matched controls performed aurally-paced thumb-finger sequencing movements with their intact hand (matching hand in case of controls) under visual guidance during four conditions: 1) intact hand (ME), 2) ME with motor imagery of the amputated hand, 3) ME with virtual visual feedback of the amputated hand, and 4) ME with motor imagery and the virtual visual feedback of the amputated hand. In contrast to controls, amputees showed increases in activity during all four conditions within the former functionally-defined sensorimotor hand territory. Movements of the intact hand likely increase activity in the former hand territory as a result of decreased interhemispheric inhibition. This stimulation may maintain deafferented hand representations that can recover soon after the afferent input is restored by hand transplantation.
354

Influência do laser em baixa intensidade no processo de reparo de de enxerto ósseo autógeno implantado em bloco na mandíbula de ratos modificados sistemicamente com nicotina: estudo histo- morfométrico

Moraes, Ricardo Oliveira de [UNESP] 18 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-18Bitstream added on 2014-06-13T20:57:34Z : No. of bitstreams: 1 moraes_ro_me_araca.pdf: 3762007 bytes, checksum: 9c2ec9715d0b3a85fbf41e3f7be91181 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução: A nicotina, uma das drogas mais nocivas a saúde, causa, entre outros fatores, morbidade do enxerto ósseo e compromete a cicatrização óssea. Por outro lado, o tratamento com laser em baixa intensidade pode proporcionar efeitos bioestimulantes, aumentando a microcirculação sanguínea da área irradiada e estimulando fibroblastos, promovendo melhores condições de cicatrização. O objetivo do presente estudo foi analisar a influência do laser em baixa intensidade sobre o processo de reparo de enxertos ósseos autógenos em bloco instalados em animais modificados sistemicamente pelos efeitos indesejáveis da nicotina. Materiais e Métodos: Foram utilizados 72 ratos (Wistar) divididos em Grupo A (n=36), subgrupos GI e GII, submetidos à aplicação de nicotina e Grupo B (n=36), subgrupos GIII e GIV, submetidos à aplicação de solução fisiológica. Transcorridos 30 dias das aplicações, todos animais receberam enxerto ósseo autógeno na mandíbula, tendo como área doadora o osso parietal da calvária, sendo que os animais pertencentes aos subgrupos GII e GIV, receberam o tratamento com laser em baixa intensidade na interface enxerto-leito receptor. Os animais de cada grupo foram submetidos à eutanásia aos 7, 14 e 28 dias pós cirurgia de enxerto. Após o processamento laboratorial de rotina foi realizada a análise histomorfométrica, visando analisar qualitativamente e quantitativamente as etapas presentes nesse processo de reparo ósseo. Resultados: A análise histológica revelou que o grupo nicotina apresentou um atraso da atividade osteogênica na interface enxerto-leito receptor, como também menor organização do tecido de granulação em substituição ao coágulo sanguineo. Contudo, a irradiação do tecido com laser em baixa intensidade proporcionou melhor reparo ósseo. Histometricamente, os subgrupos submetidos à irradiação laser... / Background: The nicotine is one of the mostly drugs more harmful to the health cause, among other factors, morbidity of bone graft and compromises bone healing. Furthermore, treatment with low level laser can provide biostimulation effects, increasing the blood microcirculation in the irradiated area and stimulating fibroblasts promoting better healing. The aim of this study was to evaluate the influence of low level laser therapy on the healing process of autogenous bone grafts installed in block in systemic modificated animals by undesirable effects of nicotine. Methods: Were used 72 rats (Wistar) divided into Group A (n = 36) subgroups GI and GII, submitted to the application of nicotine and Group B (n = 36) subgroups GIII and GIV, submitted to the application of saline solution. After 30 days of applications, all animals received autogenous bone block graft stabilized on mandible, with the parietal bone donor area of the skull, and the animals belonging to subgroups GII and GIV received treatment with low level laser in the bed-graft interface. The animals in each group were euthanized at 7, 14 and 28 days after bone graft surgery. After routine processing was performed histomorphometric analysis in order to analyze qualitatively and quantitatively the timing sequence of bone repair. Results: The histological analysis revealed that the nicotine group showed a delay of osteogenic activity in the bed-graft interface, as well as decreased organization of granulation tissue replacing the blood clot. However, the low level laser irradiation showed better bone healing. Histometrically, the laser subgroups (GII and GIV) demonstrated greater bone formation compared with the respective subgroups (GI and GIII), with significantly statistically results (P˂0) at 14 days (GI 14,27% ± 2,22% versus GII 24,37% ± 11,93% and GIII 24,94% ± 13,06% versus ...(Complete abstract click electronic access below)
355

Qualidade de vida pÃs-transplante de fÃgado em um Centro de ReferÃncia no nordeste do Brasil / QUALITY OF LIFE LIVER POST-TRANSPLANTATION IN A REFERENCE CENTER IN NORTHEASTERN BRAZIL

Maria Ãsis Freire de Aguiar 21 March 2014 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
356

InfecÃÃes relacionadas à assistÃncia à saÃde e fatores associados em pacientes transplantados renais em Fortaleza â CE. / Healthcare-related infections and associated factors in renal transplant recipients in Fortaleza-CE.

Regina Kelly GuimarÃes Gomes 17 July 2014 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / As infecÃÃes relacionadas à assistÃncia à saÃde estÃo entre as principais complicaÃÃes em pacientes que se submetem a transplante de rim, em virtude, nÃo somente, dos regimes de imunossupressÃo a que estÃo submetidos, como a cuidados desempenhados pelas equipes de saÃde. O objetivo deste estudo foi analisar infecÃÃes relacionadas à assistÃncia à saÃde em pacientes transplantados renais em 2012, no MunicÃpio de Fortaleza, que possui serviÃos de transplante renal consolidados. Fez-se um estudo transversal onde foram analisadas as fichas ambulatoriais, prontuÃrios e fichas de notificaÃÃo e investigaÃÃo da CCIH de pacientes que realizaram transplante renal em 2012, no HUWC e HGF, instituiÃÃes com recordes sucessivos neste tipo de procedimento. Um total de 237 participantes, sendo, 101 (mÃdias de idade: 43,2 anos) pertencentes ao HUWC e 136 (mÃdias de idade: 45,4 anos) ao HGF, foi incluÃdo no estudo. Em ambas as instituiÃÃes, a maioria das pessoas era do sexo masculino, casada e residia na Capital do CearÃ. Grande parte delas tambÃm tinha o IMC normal, era hipertensa, tinha como principais causas de IRC: inderterminada, HAS e nefrites. A proporÃÃo de procedimentos invasivos realizados foi: biopsia do enxerto (HUWC: 45,54%; HGF: 26,47%), punÃÃo de cateter venoso central (HUWC: 98,01%; HGF: 97,06%), FAV (HUWC: 66,33%; HGF: 94,11%), e passagem de cateter duplo J (HUWC: 39,6%; HGF: 22,06%). A estimativa de prevalÃncia de IRAS nos 101 pacientes transplantados renais no HUWC foi de 50 (49,05%), e no HGF, 31 (22,79%). As IRAS mais comuns, tanto no HUWC, como no HGF, foram infecÃÃes do trato urinÃrio, e os principais agentes etiolÃgicos isolados, Klebsiella pneumoniae e Escherichia coli. No HUWC, os fatores sociodemogrÃficos, clÃnicos e epidemiolÃgicos que apresentaram associaÃÃo estatisticamente significante com o acometimento por IRAS foram: a classificaÃÃo do IMC (p<0,03), o tempo em diÃlise antes do transplante (p<0,05), o tempo de internaÃÃo total (p<0,0001), o tempo de cirurgia (p<0,001), o tempo de isquemia fria (p<0,01), a passagem de cateter duplo J (p<0,003), o tempo de uso do TOT (p<0,03) e o tempo de uso da SVD (p<0,04) no HUWC; no HGF, a classificaÃÃo do IMC (p<0,04), o LES como causa de IRC (p<0,01), a transfusÃo sanguÃnea antes do transplante (p<0,02), o tempo de internaÃÃo total (p<0,001) e o tempo de uso do CVC (p<0,04). Portanto, durante todo o perÃodo perioperatÃrio, hà necessidade de desenvolvimento de aÃÃes cautelosas por toda a equipe de saÃde, de forma a prevenir infecÃÃes e gastos desnecessÃrios do governo com internamentos e tratamentos prolongados, sustentando o crescimento da tÃcnica de transplantaÃÃo renal no Estado nos Ãltimos anos. / The healthcare-related infections are among the major complications in patients who undergo kidney transplant, by virtue not only of immunosuppression schemes to which they are subjected, as the care carried out by health teams. The aim of this study was to analyze healthcare-related infections in renal transplant recipients in 2012, in the city of Fortaleza, which has consolidated renal transplant services. A cross-sectional study where outpatient records were analyzed, charts and tokens for notification and investigation of patients who performed CCIH kidney transplant in 2012, in HUWC and HGF, institutions with successive records in this type of procedure. A total of 237 attendees, being, 101 (average age: 43.2 years) belonging to the HUWC and 136 (average age: 45.4 years) to the HGF, was included in the study. In both institutions, most people were male, married and resided in the Capital of CearÃ. Most of them also had the normal BMI was hypertensive, had as main causes of IRC: inderterminada, SAH and lupus nephritis. The proportion of invasive procedures performed were: graft biopsy (HUWC: 45.54%; HGF: 26.47%), central venous catheter puncture (HUWC: 98.01%; HGF: 97.06%), FAV (HUWC: 66.33%; HGF: 94.11%), and passage of double-J catheter (HUWC: 39.6%; HGF: 22.06%). The estimated prevalence of IRAS in 101 renal transplant recipients at HUWC was 50 (49.05%), and HGF, 31 (22.79%). The most common IRAS, both in HUWC, as in HGF, were urinary tract infections, and the main etiological agents isolated Klebsiella pneumoniae and Escherichia coli. In HUWC, the socio-demographic factors, clinicians and epidemiologists who presented statistically significant association with involvement by IRAS were: the classification of BMI (p<0.03) time on dialysis before transplantation (p<0.05), the total length of stay (p<0.0001), the time of surgery (p<0.001), cold ischemia time (p<0.01), the passage of double-J catheter (p<0.003), the speaking time of TOT (p<0.03) and time of use of the SVD (p<0.04) in HUWC; on HGF, classification of BMI (p<0.04), LES as a cause of IRC (p<0.01), blood transfusion before transplantation (p<0.02), the total length of stay (p<0.001) and time of use of the CVC (p<0.04). Therefore, throughout the perioperative period, there is a need for development of cautious actions throughout the health team, in order to prevent infections and unnecessary government spending with hospitalizations and prolonged treatments, supporting the growth of renal transplantation technique in the State in recent years.
357

Inter-centre Variation in the Management of Kidney Transplant Recipients and Its Impact on Clinical Outcomes

Tsampalieros, Anne January 2018 (has links)
Introduction: There is an increasing number of Canadians living with end stage renal disease (ESRD). Kidney transplantation is currently the best treatment for ESRD but long-term outcomes remain suboptimal. Identifying factors associated with better outcomes may lead to interventions or practice change that could improve patient survival or quality of life. The objectives of this thesis were to: i) systematically review the literature to examine centre variation in kidney transplantation outcomes and identify centre and provider level factors that may contribute to variation in outcomes; ii) describe differences that may exist at the patient, centre and provider level at the time of kidney transplantation across the six transplant centres in Ontario, Canada; iii) examine variation in graft and patient survival rates across transplant centres in Ontario; and iv) examine whether patient, centre and provider level characteristics contribute to variation in graft and survival rates across transplant centres. Methods: The first objective of this thesis was met by conducting a systematic review of the literature according to a predefined protocol. The last three objectives of the thesis were met by conducting a population based retrospective cohort study using administrative data from Ontario. Differences at the patient, centre and provider level were described at the time of kidney transplantation. Outcomes of interest included total graft loss; graft loss with follow-up censored at death; death with graft function; and total mortality. All outcomes were assessed at one year post transplantation and at the end of study follow up. Cox proportional hazards regression was used to obtain hazard ratios (HR) for each centre relative to the average across all centres. The independent effect of centre volume and provider characteristics on outcomes was also examined. Results: The systematic review identified 24 eligible studies. Outcomes included graft survival (n=24) and patient survival (n=9). The main characteristics evaluated were centre volume (n=17) and provider volume (n=2). Centre variation in graft survival was described in 80% (12/15) of studies, while less than half of studies (8/17) found a significant association between volume and graft survival. The population based retrospective cohort included 5092 adults (≥18 years) who received a primary solitary kidney transplant across 6 transplant centres in Ontario between January 1st 2000 and December 31st 2013. Variation in patient, centre and provider level factors existed across centres at the time of transplantation. At the end of study follow-up, case-mix adjusted HRs for total graft loss ranged from 0.84 (95% CI 0.53-1.33) to 1.16 (95% CI 1.00-1.34) across centres (p-value for between centre variation 0.46). After adjusting for centre and provider factors, differences across centres persisted. Centre volume, provider experience and provider type were not independently associated with either short or long-term outcomes (all p>0.05) with the exception of graft loss with follow-up censored at death. Discussion: This thesis suggests that there is variation in clinical outcomes across transplant centres in Ontario which is not explained by patient factors, centre volume or provider characteristics at the time of transplantation. Additionally centre volume, provider type and experience were not independently associated with outcomes. Future prospective studies with a larger sample size of transplant centres that examine follow-up care after discharge from hospital (e.g. frequency of visits) are required to better understand this phenomenon.
358

Evidence based hypothermic preservation of the kidney and liver for transplantation

O'Callaghan, John M. January 2014 (has links)
No description available.
359

Effet d’un peptide mimant le domaine N-terminal de la thrombospondine-1 sur les propriétés fonctionnelles des progéniteurs endothéliaux in vitro et in vivo : proposition d’un produit de thérapie cellulaire / Effect of a peptide mimicking the N-terminal domain of thrombospondin-1 on the functional properties of endothelial progenitor cells in vitro and in vivo : a proposal cellular therapy product

Dias, Juliana Vieira 09 February 2012 (has links)
Les progéniteurs endothéliaux circulants (EPC) sont recrutées par des sites de néovascularisation active chez l’adulte et contribuent à la réparation endothéliale et à la biologie vasculaire, dans un processus appelé vasculogenèse post-natale. Ainsi, les EPC représentent une source importante pour la thérapie de néovascularisation dans la maladie artérielle périphérique, l’ischémie du myocarde et l’accident vasculaire cérébral. Considérant que les EPC potentiellement fonctionnels sont limités dans la circulation périphérique, plusieurs molécules pro-angiogènes ont été étudiées comme agents pharmacologiques dans le but d'améliorer le recrutement des progéniteurs dans la moelle osseuse vers la circulation et la capacité d'adhérence à l'endothélium afin d’obtenir une transplantation plus efficace. La thrombospondine-1 (TSP-1) est une glycoprotéine sécrétée lors de situations ischémiques qui joue un double rôle : elle est capable d’inhiber et de stimuler l'angiogenèse. Cette double activité biologique est attribuée aux interactions de ses multiples fragments avec différents récepteurs de la surface cellulaire ainsi qu’avec des molécules solubles ou protéines ancrées à la matrice extracellulaire. L'effet pro-angiogène de la TSP-1 est assigné au domaine N-terminal qui a une forte affinité à l'héparine et aux protéoglycanes. Les recherches antérieures de notre laboratoire ont indiqué deux séquences peptidiques situées dans le domaine N-terminal de la TSP-1 (TSP-HepI, acides aminés 17-35 et TSP-HepII, acides aminés 78-94), capables d'induire la différenciation des cellules endothéliales matures (HUVEC) dans les structures vasculaires in vitro en interagissant avec le syndécanne-4, un protéoglycane héparin-sulfate membranaire impliqué dans l'adhésion focale. L’objectif de ce travail était d'étudier le potentiel de la TSP-1 comme molécule stratégique pour promouvoir une augmentation de la néovascularisation dans les tissus ischémiés, induite par des EPC en essais in vitro et in vivo. Dans un premier temps, nous avons démontré que les EPC du sang périphérique, isolées et accrues avec un milieu de culture modifié dans notre laboratoire (EGM-2/ENR), présentaient les caractéristiques phénotypiques et fonctionnelles des cellules formant des colonies endothéliales (ECFC) avec un haut potentiel prolifératif. Par ailleurs, ces progéniteurs endothéliaux nommées PB-ECFC ont sécrèté trois fois plus la quantité de fibronectine que les HUVEC et ont montré un réarrangement des filaments d'actine compatible avec un phénotype migratoire. Ensuite, nous avons démontré que les peptides TSP-HepI et TSP-HepII stimulaient les étapes-clés de l'angiogenèse in vitro (le chimiotactisme, l'adhésion cellulaire et la différenciation en structures capillary-like), induites par des PB-ECFC et des ECFC isolées du sang de cordon ombilical. En plus de cela, le TSP-HepI potentialise la néovascularisation in vivo induit par le FGF-2 dans les essais de matrigel plug chez la souris. Le pré-conditionnement ex vivo d’ECFC isolées du sang de cordon ombilical avec la TSP-HepI a stimulé leur migration, l'augmentation de l'expression de l'intégrine-α6 et a augmenté leur adhésion à l'endothélium activé sous condition physiologique de flux. Ce dernier effet semble être influé par le syndécanne-4, on constate que l'adhésion des ECFC est considérablement réduite en présence d’un anticorps anti-syndécan-4. La migration et la tubulogénèse ont été réduites en utilisant un peptide TSP-HepI modifié dans les sites de liaison à l’héparine (S/TSP-HepI), ou lorsque HSPG a subi une dégradation enzymatique. Ces résultats suggèrent ainsi que le domaine N-terminal de la TSP-1 pourrait être utilisé comme molécule pharmacologique pour augmenter le potentiel biologique des ECFC dans la thérapie cellulaire de néovascularisation. / Pas de résumé anglais / As células progenitoras endotreliais (EPCs) são recrutadas para sítios de ativa neovascularização no adulto contribuindo para a biologia vascular e o reparo endotelial, processo denominado vasculogêsene pós-natal. Dessa forma, as EPCs representam uma importante fonte de terapia de neovascularização para a doença arterial periférica, a isquemia do miocárdio e o acidente vascular cerebral. Considerando que as EPCs potencialmente funcionais são limitadas na circulação, diversas moléculas pró-angiogênicas tem sido estudadas como agentes farmacológicos com o objetivo de melhorar o recrutamento das células progenitoras da medula óssea para a circulação, a capacidade de retenção no endotélio e portanto a eficiência do transplante. A trombospondina-1 (TSP-1) é uma glicoproteína secretada em situações isquêmicas que exerce um papel de destaque, sendo capaz tanto de inibir quanto de estimular a angiogênese. A dupla atividade biológica da TSP-1 é atribuída às interações de seus domínios com diferentes receptores de superfície celular assim como à proteínas solúveis ou ancoradas à matriz extracelular. O efeito pró-angiogênico da TSP-1 é atribuído ao domínio N-terminal que possui alta afinidade à heparina e a proteoglicanos. Dados obtidos em nosso laboratório apontaram duas sequências peptídicas localizadas dentro do domínio N-terminal da TSP-1 (TSP-HepI, aminoácidos 17-35 e TSP-HepII, aminoácidos 78-94), capazes de induzir a diferenciação de células endoteliais maduras (HUVECs) em estruturas vasculares in vitro, interagindo o sindecan-4, um proteoglicano de heparan sulfato membranar, envolvido na adesão focal. Nosso objetivo nesse trabalho foi investigar o potencial da TSP-1 como molécula estratégica para promover o aumento da neovascularização nos tecidos isquêmicos induzida por EPCs em ensaios in vitro e in vivo. Nós demonstramos inicialmente que as EPCs do sangue períférico isoladas e expandidas com o meio de cultura produzido no nosso laboratório, EGM-2/ENR, exibem caracaterísticas fenotípicas e funcionais de células endoteliais formadoras de colônias ou ECFCs e alto potencial proliferativo. Além disso, esses progenitores que vamos denominar PB-ECFCs, secretam 3 vezes mais fibronectina que as HUVECs e possuem um rearranjo do filamentos de actina compatível com o fenótipo migratório. Nós demonstramos em seguida que os peptídeos TSP-HepI e TSP-HepII, estimulam etapas-chave da angiogênese in vitro (quimiotaxia, adesão estática e diferenciação em estruturas tipo-capilares) induzida por PB-ECFCs e ECFCs isoladas do sangue de cordão umbilical. Além disso TSP-HepI potencializou a neovascularização in vivo, induzida pelo FGF-2 no ensaio de matrigel plug em camundongos. O pré-condicionamento ex vivo das ECFCs isoladas do sangue de cordão umbilical com TSP-HepI estimulou a migração, aumentou a expressão da integrina-α6 e aumentoua adesão ao endotélio ativado em condições fisiológicas de fluxo. Este último efeito foi mediado pelo sindecan-4, visto que a adesão foi inibida pelo anticorpo anti-sindecan-4. Além disso a migração e a tubulogênese foram efeitos reduzidos pelo uso do TSP-HepI modificado no sítio de ligação à heparina (S/TSP-HepI), ou quando o HSPG foram removidos enzimaticamente, respectivamente. Esses achados reunidos sugerem que o domínio N-terminal da TSP-1 poderia ser aplicado como uma molécula farmacológica para aumentar o potencial biológico das ECFCs na terapia celular de neovascularização.
360

Effect of low level laser irradiation on human adult adipose derived stem cells: an in vitro study

Mvula, Bernard Dandenault 16 March 2010 (has links)
M. Tech. / Stem cells are defined as undifferentiated cells that can proliferate indefinitely and have the capacity of both self-renewal and differentiation to one or more types of specialised cells. Traumatic tissue injury and age-related degenerative diseases are a major problem in South Africa and worldwide. Stem cells could be used for tissue engineering and reconstructive surgery. In treating these conditions, the main principle of stem cell therapy is the replacement of damaged and dead cells in injured tissues and organs with new healthy ones expanded in vitro from stem cells (Orlic et al., 2002). These cells can be isolated from adipose tissue in significant numbers and exhibit stable growth and proliferation kinetics in culture and could be differentiated into bone, fat, cartilage and muscle when treated with established lineage-specific factors (Zuk et al., 2002). Low Level Laser Therapy (LLLT) is currently applied in the treatment of numerous diseases and pathological conditions (Gasparyan et al., 2004). LLLT produces positive effects on irradiated cells and tissues such as proliferation of cells, capillary growth and adenosine triphosphate (ATP) activation (Schindl et al., 1998). Low level laser radiation at different intensities has been shown to stimulate as well as to inhibit cellular processes (Moore et al., 2005). Epidermal growth factor (EGF) is a growth factor that plays important roles in the regulation of cell growth, proliferation and differentiation. This study investigated the effect of low level laser radiation alone as well as in combination with EGF on adult adipose derived stem cells (ADSCs) isolated from human adipose tissue. ADSCs were isolated from human adipose tissue through collagenase digestion and cultured in DMEM-F12 containing 10% FBS and antibiotics and incubated at 37°C in a humidified atmosphere of 5% CO2 (Zuk et al., 2001). iii Semi-confluent monolayers of ADSCs were exposed to low level laser at 5 J/cm2 using 636 nm diode laser with a power density of 12.1 mW/cm2 at room temperature in the dark. Cell morphology was monitored at 0, 24 and 48 h using an inverted light inverted microscope. Cell viability was evaluated at 0, 24 and 48 h using the Trypan Blue exclusion test and an adenosine triphosphate (ATP) luminescence assay. bFGF (basic fibroblast growth factor) indirect ELISA and optical density assays were used to monitor cell proliferation at 0, 24 and 48 h post irradiation. In addition the expressions of stem cell markers, β1-integrin and Thy-1, were monitored by immunocytochemical live cell surface labelling and Western blot analysis. Cells were incubated with EGF to enhance proliferation and differentiation and the cell morphology, viability and proliferation were monitored as well as the expressions of stem cell markers, β1-integrin and Thy-1. Morphology of the cells was not altered by irradiating them with 5 J/cm2 using diode laser at 0, 24 and 48 h. Cell viability and proliferation showed an increase at 24 and 48 h post irradiation. At 0 h, there was no significant difference between irradiated and non-irradiated cells in cell viability and proliferation. There was an increase in the expression of β1-integrin and Thy-1 after irradiation as shown by Western blot analysis and immunocytochemical live cell surface labelling. Cell viability and proliferation showed a significant increase at all time points post irradiation with the addition of EGF. There was no noticeable change in cellular morphology at any time point. Low level laser irradiation of human ADSC’s at 636 nm with 5 J/cm2 and 12.1 mW/cm2 increased the viability and proliferation of these cells in vitro. Furthermore, low level laser irradiation appeared to increase the expression of stem cell markers, β1-integrin and Thy-1. In addition, laser irradiation did not alter the morphology of the cultured cells. The addition of EGF to the cells also increased their viability and proliferation as well the expression of the markers, β1-integrin and Thy-1. The study showed that laser irradiation stimulates two important cellular responses namely cell viability and proliferation which indicates that ADSCs may be suitable for tissue engineering and future cell differentiation studies.

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