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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

Role of the CD154-CD40 axis in the modulation of autoimmune reactions

Mars, Leonardus Theodorus January 2000 (has links)
No description available.
12

Beurteilung subklinischer akuter zellulärer Abstoßungsreaktion nach Herztransplantation: Vergleich der kardialen Magnetresonanztomographie mit der endomyokardialen Biopsie

Krieghoff, Christian 26 September 2016 (has links) (PDF)
Für Patienten mit fortgeschrittener Herzinsuffizienz ist die Herztransplantation die einzige kurative Therapieoption. Die akute Abstoßungsreaktion ist ein entscheidender Faktor der Mortalität nach Transplantation. Zur Früherkennung einer Abstoßungsreaktion gilt nach wie vor die Endomyokardbiopsie als Goldstandard. Diese stellt jedoch ein invasives Verfahren mit seltenen, aber potentiell schwerwiegenden Komplikationen dar. In der vorliegenden Studie wurde die diagnostische Wertigkeit der kardialen Magnetresonanztomographie zur Detektion der Abstoßungsreaktion nach Herztransplantation untersucht. Als Referenz diente die Myokardbiopsie mit histologischer Beurteilung nach dem Schema der International Society of Heart and Lung Transplantation (ISHLT). Insbesondere bei Kombination mehrerer Parameter konnte ein hoher negativ prädiktiver Wert zum Ausschluss einer akuten Abstoßungsreaktion erzielt werden. Dagegen waren Spezifität und positiv prädiktiver Wert zu gering, um eine Therapie-Änderung alleine auf Basis eines positiven MRT-Befundes zu rechtfertigen.
13

Tacrolimus pharmacogenomics in abdominal solid organ transplantation

Falconer, Stuart John January 2018 (has links)
Background: Abdominal solid organ transplantation has evolved from an experimental procedure to a well-established therapy within a few decades. This success is largely due to the introduction of calcineurin inhibitor immunosuppression. Tacrolimus is the most widely used calcineurin inhibitor but has a narrow therapeutic range which requires close drug monitoring to prevent both toxicity and inadequate immunosuppression. Previous studies in renal transplantation have shown that genetic polymorphisms, CYP3A5, CYP3A4*22 and ABCB1 can influence the bioavailability and pharmacokinetics of tacrolimus. These polymorphisms are closely linked to ethnicity and have never been studied in a Scottish population before. Additionally, increasing evidence suggests that high variability of tacrolimus is linked to increased graft loss in kidney transplant patients. Methods: 5889 subjects were genotyped for the genetic polymorphisms CYP3A5 A > G allele transition, CYP3A4*22 C > T and ABCB1 C > T transition. This included 4899 healthy individuals from Generation Scotland bio-resource and 990 patients who underwent renal, liver, or simultaneous pancreas kidney transplants or were organ donors. Tacrolimus dose, trough level and renal function were measured at 11 time points from date of transplant up to and including 12 months post-transplant. Clinical data including episodes of acute rejection, graft and patient survival were compared between the different genotypes. Separate analyses were undertaken for kidney, SPK transplants, as well as liver transplants, the latter looking at recipient and liver donor genotype. A separate cohort of 103 renal transplant patients converted from twice-daily to once-daily tacrolimus had their tacrolimus variability calculated and compared with graft survival. Results: The distribution of the 3 different genotypes of CYP3A5, CYP3A4*22 and ABCB1 were comparable with other Caucasian populations studied previously. In renal transplant recipient expression of the A allele (GA/AA) led to significantly increased dose requirements of tacrolimus and initially lower tacrolimus trough levels. The different genotypes of ABCB1 had no effect. Expression of a CYP3A4*22 T allele trended towards a lower tacrolimus dose requirement but this was not significant. There was no difference in renal function, graft survival or patient survival with any of the polymorphisms. SPK patients had comparable results. In the liver transplant patients, the donor genotype had a greater influence than the recipient one. The donors with CYP3A5 A allele expression had significantly higher tacrolimus dose requirements and lower initial tacrolimus levels. This was apparent to a lesser extent with the recipient expression of CYP3A5 and did not reach statistical significance at all time points. There was no significant difference in tacrolimus dose requirements or level with either donor or recipient expression of ABCB1 or CYP3A4*22. There was a significantly higher incidence of acute rejection in donor CYP3A5 A allele expressers of liver transplant patients in univariate and multivariate analysis. There was no significant different in acute rejection with ABCB1 or CYP3A4*22 genotype. No differences in graft or patient survival with either donor or recipient genotype of any of the 3 polymorphisms were noted. Conversion from twice-daily to once-daily tacrolimus in the first 12 months post-transplant reduced tacrolimus variability. Patients with high tacrolimus variability pre and post conversion had significantly greater graft loss than patients with low tacrolimus variability. Conclusion: CYP3A5 expression results in increased tacrolimus requirements to achieve adequate immunosuppression in renal transplant and SPK patients. Donor rather than recipient CYP3A5 expression is relevant for liver transplantation and dose requirements. There may be an association with donor CYP3A5 expression in liver transplant patients and acute rejection which needs further evaluation. ABCB1 and CYP3A4*22 do not appear to have a significant impact in any of the organ transplants. High tacrolimus variability is associated increased graft loss in renal transplant patients.
14

Robust Learning Algorithms for Bioengineering Systems

Nadadoor Srinivasan, Venkat R. Unknown Date
No description available.
15

Detection of Protein Analytes in Physiologic Environments via Planar ImmunoHFET

Casal, Patricia 18 December 2012 (has links)
No description available.
16

Agentes infecciosos no coração de pacientes com cardiomiopatia dilatada idiopática: possível relação com rejeição pós-transplante cardíaco / Infectious agents in heart of patients with idiopathic dilated cardiomyopathy: potential relation with rejection of cardiac transplantation

Pereira, Jaqueline de Jesus 23 April 2019 (has links)
A cardiomiopatia dilatada (CMD) é caracterizada pela dilatação progressiva com redução da função contráctil do ventrículo esquerdo ou de ambos os ventrículos, podendo ser de origem viral e/ou imune, genética ou idiopática. Devido às inúmeras variáveis envolvidas na patogênese da CMD, atualmente não existe uma opção terapêutica definitiva para seu tratamento, sendo o transplante cardíaco o tratamento de escolha para a insuficiência cardíaca refratária. Trabalho anterior aventou a hipótese de simbiose entre microrganismos interferindo na resposta imune no tecido miocárdico. Assim, o presente estudo teve como objetivo verificar se a presença de antígenos ou DNA de agentes infecciosos associados à inflamação em corações explantados de pacientes com CMD Idiopática está relacionada com o desenvolvimento de rejeição moderada/grave no coração do doador após o transplante cardíaco. Foram estudadas amostras de miocárdio de pacientes transplantados por CMD Idiopática, agrupadas em: RMP (N = 6), rejeição moderada persistente, RM (n = 7) rejeição resolvida após pulsoterapia e SR (n = 5) sem rejeição. A inflamação foi quantificada por imunohistoquímica e os agentes infecciosos por imunohistoquímica, biologia molecular, hibridação in situ e microscopia eletrônica de transmissão. Houve maior número de macrófagos no grupo RMP, e mais células B e maior expressão de HLA classe II no grupo SR. A imunohistoquímica mostrou maior quantidade de M. pneumoniae e de HBC nos grupos RMP e RM. O grupo SR mostrou correlação positiva entre quantidade de gene Bb e antígeno de enterovírus. A biologia molecular demonstrou a presença dos genes M. pneumoniae, Borrelia burgdorferi, HHV6 e PVB19 em todos os grupos de estudo. A microscopia eletrônica revelou a presença de estruturas compatíveis com microrganismos que apresentam características de micoplasma, borrelia, enterovírus, HHV6 e parvovírus. Agentes infecciosos podem ser o fator causal e/ou perpetuador da lesão miocárdica em pacientes com CMD idiopática, uma vez que esses achados iniciais sugerem que a presença de microrganismos em simbiose no miocárdio está associada com pior prognóstico pós-transplante / Dilated cardiomyopathy (DCM) is characterized by progressive dilation with reduction of contractile function of the left ventricle or both ventricles, which may be viral and/or immune, genetic or idiopathic. Because of countless variables involved in the DCM, currently there is no definitive therapeutic option for its treatment, being heart transplant the treatment for choice of refractory heart failure. A previous study hypothesized that symbiosis between microorganisms may interfere in immune system in myocardial tissue. Thus, the present study had the objective to determine if presence of antigens or DNA of infectious agents associated with inflammation in explanted hearts of patients with idiopathic DCM is related to the development of moderated/severe rejection in donor\'s heart after cardiac transplantation. Myocardial samples from patients transplanted by Idiopathic DCM were studied, grouped in: PMR (n=6) persistent moderate rejection, MR (n=7) rejection resolved after pulse therapy and NR (n=5) no rejection, without moderate rejection, in which inflammation was quantified by immunohistochemistry and infectious agents by immunohistochemistry, molecular biology, in situ hybridization technique and transmission electron microscopy. There was higher amount of macrophages in PMR group, and more B cells (p=0.0001) and higher HLA class II expression (p= < 0.0001) in NR group. Immunohistochemistry showed M. pneumoniae (p=0.003) and HBc (p=0.0009) antigens in PMR and MR groups. NR showed positive correlation between amount of Bb genes and enterovirus antigens. Molecular biology demonstrated the presence of M. pneumoniae, Borrelia burgdorferi, HHV6 and PVB19 genes in all studied groups. Electron microscopy revealed the presence of structures compatible with mycoplasma, borrelia, enterovirus, herpesvirus 6 and parvovirus. Infectious agents may be the causal and/or perpetuating factor of myocardial injury in patients with Idiopathic DCM, since these initial findings suggest that the microorganisms in symbiosis in the myocardium of these patients is associated with worst prognosis after transplantation
17

Beurteilung subklinischer akuter zellulärer Abstoßungsreaktion nach Herztransplantation: Vergleich der kardialen Magnetresonanztomographie mit der endomyokardialen Biopsie

Krieghoff, Christian 13 September 2016 (has links)
Für Patienten mit fortgeschrittener Herzinsuffizienz ist die Herztransplantation die einzige kurative Therapieoption. Die akute Abstoßungsreaktion ist ein entscheidender Faktor der Mortalität nach Transplantation. Zur Früherkennung einer Abstoßungsreaktion gilt nach wie vor die Endomyokardbiopsie als Goldstandard. Diese stellt jedoch ein invasives Verfahren mit seltenen, aber potentiell schwerwiegenden Komplikationen dar. In der vorliegenden Studie wurde die diagnostische Wertigkeit der kardialen Magnetresonanztomographie zur Detektion der Abstoßungsreaktion nach Herztransplantation untersucht. Als Referenz diente die Myokardbiopsie mit histologischer Beurteilung nach dem Schema der International Society of Heart and Lung Transplantation (ISHLT). Insbesondere bei Kombination mehrerer Parameter konnte ein hoher negativ prädiktiver Wert zum Ausschluss einer akuten Abstoßungsreaktion erzielt werden. Dagegen waren Spezifität und positiv prädiktiver Wert zu gering, um eine Therapie-Änderung alleine auf Basis eines positiven MRT-Befundes zu rechtfertigen.:1 Titelblatt 1 2 Bibliographische Beschreibung 4 3 Einführung 5 3.1 Hintergrund zur Herztransplantation 5 3.1.1 Indikation und Epidemiologie 5 3.1.2 Abstoßungsreaktion und Immunsuppression 6 3.1.3 Statistiken zu Abstoßung und Immunsuppression 8 3.1.4 Verfahren und Probleme der Endomyokardbiopsie 10 3.2 Bisherige Ansätze zum nicht-invasiven Screening 12 3.2.1 Echokardiographie 12 3.2.2 Elektrokardiogramm 14 3.2.3 Biomarker im peripheren Blut 14 3.2.4 Kardiale Magnetresonanztomographie 16 3.3 Rationale und Fragestellungen zur vorliegenden Studie 19 4 Publikationsmanuskript 21 5 Zusammenfassung der Arbeit 33 6 Anlagen 39
18

Análise clínica evolutiva do uso do tacrolimus como droga imunossupressora em transplante cardíaco pediátrico / Clinical outcome of tacrolimus as maintenance immunosuppressive drug in pediatric heart transplantation

Klébia Magalhães Pereira Castello Branco 28 February 2011 (has links)
O Tacrolimus é uma potente droga imunossupressora introduzida no transplante cardíaco no início da década de 90. Pacientes com rejeição refratária ou intolerância à ciclosporina podem responder à terapia de resgate com o tacrolimus. Os objetivos deste estudo foram: avaliar a evolução clínica das crianças submetidas ao transplante cardíaco que necessitaram da conversão de ciclosporina para tacrolimus por rejeição refratária, tardia ou efeitos adversos de difícil controle; avaliar a incidência de rejeição após a conversão para o tacrolimus e comparar a sobrevida dos pacientes em uso de tacrolimus e ciclosporina. Realizou-se estudo coorte, observacional, prospectivo, em 28 crianças submetidas ao transplante cardíaco no Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e que foram submetidas à conversão da ciclosporina ao tacrolimus, no período de julho de 1999 a dezembro de 2009. Avaliou-se a incidência de episódios de rejeição e a sobrevida após a conversão. Realizou-se, também, a comparação entre os pacientes em uso de tacrolimus e os pacientes que permaneceram em uso de ciclosporina submetidos ao transplante cardíaco no mesmo período. A idade média no momento do transplante foi de 5,3 anos, e no momento da conversão de 8,2 anos. As causas de conversão foram efeitos adversos em 50% dos pacientes, rejeição tardia em 32% e rejeição refratária em 18%. O tempo médio de conversão e seguimento foram 36 meses e 74 meses, respectivamente. Observou-se resolução completa dos episódios de rejeição refratária e melhora dos efeitos adversos em todos os pacientes. A taxa de incidência (x100) de episódios de rejeição antes da conversão foi de 7,98 e após a conversão foi de 2,11 (p=0,0001). A taxa de episódios de infecção antes da conversão foi de 5,89 e após a conversão 4,18 (p=0,023). Pela análise das complicações pré e pós-conversão ao tacrolimus, não se evidenciou diferença estatisticamente significativa em relação a incidência de tumor, insuficiência renal, hipertensão arterial sistêmica, dislipidemia, litíase biliar, diabetes melito, anemia, alterações neurológicas, hirsutismo e hiperplasia gengival. Houve maior prevalência da doença vascular do enxerto após conversão para tacrolimus (p=0,004). Ao se comparar os pacientes com tacrolimus e os com ciclosporina, identificou-se diminuição significativa na taxa de incidência de episódios de rejeição (p=0,001), e na taxa de incidência de episódios de infecção (p=0,002), nos pacientes em uso de tacrolimus. Os pacientes convertidos ao tacrolimus apresentaram menor incidência de complicações neurológicas, hirsutismo e hiperplasia gengival, porém maior prevalência de anemia. Em relação à sobrevida, observou-se uma mortalidade de 25% nos pacientes em uso de tacrolimus, após um período médio de conversão de sessenta meses. Três óbitos foram secundários à rejeição, dos quais apenas um, no primeiro ano de transplante. Evidenciou-se menor sobrevida nos pacientes em uso de ciclosporina. O estudo clínico das crianças submetidas ao transplante cardíaco e que necessitaram de conversão do esquema de imunossupressão permitiu concluir que o tacrolimus foi eficaz como terapia de resgate para rejeição refratária e constitui opção terapêutica como droga imunossupressora de manutenção na faixa etária pediátrica / Tacrolimus is a potent calcineurin inhibitor that was introduced in heart transplantation therapy in the early 1990s. Organ transplant recipients with refractory rejection or intolerance to conventional immunosuppressant may respond to rescue therapy with tacrolimus. The aim of this study was to evaluate the clinical outcome of children undergoing heart transplantation who required conversion from a cyclosporine to a tacrolimus-based immunosuppressive regimen due to refractory rejection, late rejection or cyclosporine intolerance. We performed a prospective observational cohort study in 28 children who underwent cardiac transplantation at the Heart Institute (InCor) University of São Paulo Medical School and who required conversion from July 1999 to December 2009. The clinical outcome of the patients was evaluated after tacrolimus conversion. We also compared the patients on tacrolimus to the patients who remained on cyclosporine, and who had undergone heart transplantation during the same period. The mean age at the time of transplantation was 5.3 years and 8.2 years at the time of conversion. The causes of conversion were adverse side effects in 50% of patients, late rejection in 32% and refractory rejection in 18%. The mean time from heart transplant to conversion was 36 months and the mean follow-up period was 74 months. We observed complete resolution of refractory rejection episodes and adverse side effects in all patients. The incidence rate (x100) of rejection episodes before and after conversion was 7.98 and 2.11, respectively (p = <0.0001). The rate of infectious episodes before conversion was 5.89 and after conversion was 4.18 (p = 0.023). There was no statistically significant difference in relation to tumor, renal failure requiring dialysis, systemic arterial hypertension, dyslipidemia, gallstones, diabetes mellitus, anemia, neurological complications, hirsutism and gingival hyperplasia after conversion. A significant incidence of cardiac allograft vasculopathy after conversion to tacrolimus was found (p = 0.004). When comparing patients on tacrolimus to patients on cyclosporine, there was a significant decrease in the incidence of rejection (p = 0.001), and infectious episodes (p = 0.002) in patients using tacrolimus. Patients converted to tacrolimus when compared to patients on cyclosporine had lower neurological complications, hirsutism and gingival hyperplasia, but higher prevalence of anemia. There was a 25% mortality rate in patients using tacrolimus after a mean period of 60 months after conversion. Three deaths were secondary to rejection, and only one in the first year after transplant. Patients using tacrolimus showed greater survival rate when compared to patients taking cyclosporine. The clinical outcome of children undergoing heart transplantation and who required conversion of immunosuppressive regimen allowed us to conclude that tacrolimus is effective as rescue therapy for refractory rejection and is a therapeutic option in pediatric patients
19

Análise clínica evolutiva do uso do tacrolimus como droga imunossupressora em transplante cardíaco pediátrico / Clinical outcome of tacrolimus as maintenance immunosuppressive drug in pediatric heart transplantation

Branco, Klébia Magalhães Pereira Castello 28 February 2011 (has links)
O Tacrolimus é uma potente droga imunossupressora introduzida no transplante cardíaco no início da década de 90. Pacientes com rejeição refratária ou intolerância à ciclosporina podem responder à terapia de resgate com o tacrolimus. Os objetivos deste estudo foram: avaliar a evolução clínica das crianças submetidas ao transplante cardíaco que necessitaram da conversão de ciclosporina para tacrolimus por rejeição refratária, tardia ou efeitos adversos de difícil controle; avaliar a incidência de rejeição após a conversão para o tacrolimus e comparar a sobrevida dos pacientes em uso de tacrolimus e ciclosporina. Realizou-se estudo coorte, observacional, prospectivo, em 28 crianças submetidas ao transplante cardíaco no Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e que foram submetidas à conversão da ciclosporina ao tacrolimus, no período de julho de 1999 a dezembro de 2009. Avaliou-se a incidência de episódios de rejeição e a sobrevida após a conversão. Realizou-se, também, a comparação entre os pacientes em uso de tacrolimus e os pacientes que permaneceram em uso de ciclosporina submetidos ao transplante cardíaco no mesmo período. A idade média no momento do transplante foi de 5,3 anos, e no momento da conversão de 8,2 anos. As causas de conversão foram efeitos adversos em 50% dos pacientes, rejeição tardia em 32% e rejeição refratária em 18%. O tempo médio de conversão e seguimento foram 36 meses e 74 meses, respectivamente. Observou-se resolução completa dos episódios de rejeição refratária e melhora dos efeitos adversos em todos os pacientes. A taxa de incidência (x100) de episódios de rejeição antes da conversão foi de 7,98 e após a conversão foi de 2,11 (p=0,0001). A taxa de episódios de infecção antes da conversão foi de 5,89 e após a conversão 4,18 (p=0,023). Pela análise das complicações pré e pós-conversão ao tacrolimus, não se evidenciou diferença estatisticamente significativa em relação a incidência de tumor, insuficiência renal, hipertensão arterial sistêmica, dislipidemia, litíase biliar, diabetes melito, anemia, alterações neurológicas, hirsutismo e hiperplasia gengival. Houve maior prevalência da doença vascular do enxerto após conversão para tacrolimus (p=0,004). Ao se comparar os pacientes com tacrolimus e os com ciclosporina, identificou-se diminuição significativa na taxa de incidência de episódios de rejeição (p=0,001), e na taxa de incidência de episódios de infecção (p=0,002), nos pacientes em uso de tacrolimus. Os pacientes convertidos ao tacrolimus apresentaram menor incidência de complicações neurológicas, hirsutismo e hiperplasia gengival, porém maior prevalência de anemia. Em relação à sobrevida, observou-se uma mortalidade de 25% nos pacientes em uso de tacrolimus, após um período médio de conversão de sessenta meses. Três óbitos foram secundários à rejeição, dos quais apenas um, no primeiro ano de transplante. Evidenciou-se menor sobrevida nos pacientes em uso de ciclosporina. O estudo clínico das crianças submetidas ao transplante cardíaco e que necessitaram de conversão do esquema de imunossupressão permitiu concluir que o tacrolimus foi eficaz como terapia de resgate para rejeição refratária e constitui opção terapêutica como droga imunossupressora de manutenção na faixa etária pediátrica / Tacrolimus is a potent calcineurin inhibitor that was introduced in heart transplantation therapy in the early 1990s. Organ transplant recipients with refractory rejection or intolerance to conventional immunosuppressant may respond to rescue therapy with tacrolimus. The aim of this study was to evaluate the clinical outcome of children undergoing heart transplantation who required conversion from a cyclosporine to a tacrolimus-based immunosuppressive regimen due to refractory rejection, late rejection or cyclosporine intolerance. We performed a prospective observational cohort study in 28 children who underwent cardiac transplantation at the Heart Institute (InCor) University of São Paulo Medical School and who required conversion from July 1999 to December 2009. The clinical outcome of the patients was evaluated after tacrolimus conversion. We also compared the patients on tacrolimus to the patients who remained on cyclosporine, and who had undergone heart transplantation during the same period. The mean age at the time of transplantation was 5.3 years and 8.2 years at the time of conversion. The causes of conversion were adverse side effects in 50% of patients, late rejection in 32% and refractory rejection in 18%. The mean time from heart transplant to conversion was 36 months and the mean follow-up period was 74 months. We observed complete resolution of refractory rejection episodes and adverse side effects in all patients. The incidence rate (x100) of rejection episodes before and after conversion was 7.98 and 2.11, respectively (p = <0.0001). The rate of infectious episodes before conversion was 5.89 and after conversion was 4.18 (p = 0.023). There was no statistically significant difference in relation to tumor, renal failure requiring dialysis, systemic arterial hypertension, dyslipidemia, gallstones, diabetes mellitus, anemia, neurological complications, hirsutism and gingival hyperplasia after conversion. A significant incidence of cardiac allograft vasculopathy after conversion to tacrolimus was found (p = 0.004). When comparing patients on tacrolimus to patients on cyclosporine, there was a significant decrease in the incidence of rejection (p = 0.001), and infectious episodes (p = 0.002) in patients using tacrolimus. Patients converted to tacrolimus when compared to patients on cyclosporine had lower neurological complications, hirsutism and gingival hyperplasia, but higher prevalence of anemia. There was a 25% mortality rate in patients using tacrolimus after a mean period of 60 months after conversion. Three deaths were secondary to rejection, and only one in the first year after transplant. Patients using tacrolimus showed greater survival rate when compared to patients taking cyclosporine. The clinical outcome of children undergoing heart transplantation and who required conversion of immunosuppressive regimen allowed us to conclude that tacrolimus is effective as rescue therapy for refractory rejection and is a therapeutic option in pediatric patients
20

Mechanisms of T Cell Reconstitution Following Lymphoablation in TransplantationAnd Description of a Novel Protective Role for T Cells in Epilepsy

Ayasoufi, Katayoun 07 February 2017 (has links)
No description available.

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