Introdução: A célula NK possui uma importante função no sistema imune inato de defesa primária contra vírus e patógenos e também realiza a imunovigilâcia tumoral. Muitos estudos clínicos tem avaliado o uso dessas células na imunoterapia adotiva. A expansão e a ativação da célula NK requer sinais e estímulos para manter a sua sobrevivência. Atualmente existem muitos protocolos para a expansão e ativação da célula NK, porém não existe uma definição do melhor método para uso clínico. Objetivo: O estudo tem como objetivo avaliar a melhor forma para expansão das células NK isoladas de células mononucleares do sangue de cordão umbilical e placentário.Método: Foram avaliadas cinco diferentes condições para expansão de células NK de mononucleares isoladas do sangue do cordão umbilical e placentário. Foram testados protocolos utilizando as interleucinas (IL), IL-2, IL-3, IL-15; com ou sem a presença do co-cultivo com células-tronco mesenquimais do cordão umbilical (CTM-CU) e, também o co-cultivo com células apresentadoras de antígeno artificiais ligadas a IL-21 à membrana (mbIL21 APC). Resultados: Os protocolos utilizando co-cultivo com APC mbIL21 foram superiores aos demais quanto à capacidade de expansão de células NK (CD3-, CD56+, CD16+). O protocolo de co-cultura de APC, CTM-CU e estímulo com IL-2 apresentaram um aumento significativo de NK (CD3-, CD56+, CD16+) quando comparado ao protocolo de APC/IL-2 sem CTM-CU (p<0,05). Conclusão: A expansão ex vivo de células NK na presença das APC e CTM-CU apresentaram uma proporção estatisticamente superior de célula NK CD16+ quando comparada com condições de cultivo com apenas a APC, tendo essas células NK potencial para utilização na imunoterapia adotiva associada com anticorpos monoclonais ou anticorpos bi-específicos. / Background: Natural killer (NK) cells play a major role in innate immunity, especially against viral pathogens, and are also a part of the immune surveillance of tumors. Several clinical trials have evaluated the use of these cells for adoptive cell immunotherapy. Ex vivo expansion of NK cells, however, is a complex process which requires multiple cell signals to ensure cell survival, proliferation, and activation. There are many protocols used for NK cell expansion and activation, however, there is a lack of evidence regarding which method is the most effective for clinical grade NK cells expansion. Objective: The main purpose of this study is to evaluate an optimal protocol for the ex vivo expansion of NK cells isolated from umbilical cord blood mononuclear cells (CB-MNC). Methods: Five different conditions for the expansion of umbilical cord-derived NK cells were evaluated. Each protocol was a different combination of interleukins (IL-2, IL-3, and IL-15) with or without the presence of feeder cells or artificial antigen presenting cells (aAPCs). Feeder cells utilized were umbilical cord-derived mesenchymal stem cells (UC-MSC), and aAPCs were membrane-bound IL-21 artificial APCs (mbIL21 aAPCs). Results: Protocols employing mbIL21 aAPCs demonstrated greater expansion of natural killer cells (CD3- CD56+) than the other protocols. The protocol employing aAPCs, IL-2 and UC-MSC feeder cells had a statistically significant higher proportion of CD16+ NK cells when compared to the protocol without the MSC feeder cells, but there was no significant difference in the expansion of total natural killer cells concerning these two protocols. Conclusion: Ex vivo expansion of NK cells in the presence of aAPCs and UC-MSC feeder cells yielded a significant higher proportion of CD16+ NK when compared to the aAPCs only culture condition, and could be a better product for NK adoptive immunotherapy in conjunction with monoclonal or bi-specific antibodies.

INTRODUÇÃO: Células-tronco mesenquimais da geleia de Wharton (GW-CTM) exibem a capacidade de modular a resposta das células T e geralmente esses efeitos imunomoduladores são anti-inflamatórios. Devido ao seu potencial imunossupressor, as CTM emergiram recentemente como uma ferramenta promissora para terapia celular. No entanto, essas células têm uma vida útil limitada in vitro, com redução progressiva da sua capacidade de autorrenovação e parada irreversível do ciclo celular. O resultado deste processo é a perda da funcionalidade das CTM, o que limita a sua utilização para fins terapêuticos. Pouco se sabe sobre a variabilidade individual das amostras de GW-CTM e como isso poderia afetar sua expansão in vitro, seu potencial imunomodulador e o processo de envelhecimento. Neste estudo, avaliamos o perfil de citocinas imunomoduladoras e a capacidade das GW-CTM inibir a proliferação de células T durante o processo de senescência replicativa para determinar se a resposta esperada é afetada. MÉTODOS: GW-CTM foram cultivadas até a senescência replicativa ser atingida; as amostras foram coletadas numa fase inicial (passagem 5), numa etapa intermediária (passagem 15) e na senescência replicativa (passagem geralmente entre 20 e 25) para análise do perfil basal de moléculas imunomoduladoras. GW-CTM foram cocultivadas com amostras de duas células mononucleares de sangue periférico (PBMC), obtidas de doadores de plaquetas saudáveis. PBMC foi estimulado com fitohemaglutinina (PHA) durante 72 horas e cocultivado com três amostras de GW-CTM diferentes para medir a supressão da proliferação das células T. Os experimentos foram realizados utilizando as passagens P5 e P10. As análises foram feitas por PCR em tempo real, western blot e citometria de fluxo. RESULTADOS: Nossos resultados mostram que a expressão gênica e a secreção de moléculas imunomoduladoras variam entre amostras de GW-CTM, sem padrão específico. Em cocultura, todas as GW-CTM foram capazes de inibir a proliferação de células T CD3+ ativadas por mitogéno, embora em diferentes graus. E cada PBMC respondeu à cocultura com um nível diferente de inibição. Além disso, o perfil imunomodulador de todas as GW-CTM foi essencialmente mantido, mesmo após várias passagens. CONCLUSÃO: Nossos dados indicam que cada GW-CTM exibe um comportamento único, diferindo nos padrões de expressão e secreção de citocinas e capacidade imunomoduladora. Essa variabilidade intrínseca entre amostras pode influenciar a eficácia de GW-CTM quando utilizadas em terapia celular / INTRODUCTION: Wharton\'s jelly mesenchymal stem cells (WJ-MSC) exhibit the ability to modulate T cell responses and these immunomodulatory effects are usually anti-inflammatory. Due to their immunosuppressive potential, MSC have recently emerged as a promising tool for cell therapy. However, MSC have a limited lifespan in vitro, with a progressive reduction in their capacity for selfrenewal leading to irreversible arrest of cell division. The result of this process is the loss of stem cell functionality, which limits its use for therapeutic purposes. Information on the variability of individual cell samples impacting upon in vitro expansion, immunomodulatory potential, and aging processes is still lacking. In this study, we evaluated the immunomodulatory cytokine profile and capacity to inhibit T cell proliferation of WJ-MSC progressing to replicative senescence to determine if the expected response is affected. METHODS: WJ-MSC were cultured until replicative senescence was reached and the samples were collected at an early stage (passage 5), at an intermediate stage (passage 15), and in replicative senescence (passage generally between 20 and 25) to analyze the basal profile of immunomodulatory molecules. WJ-MSC were co-cultured with samples from the same two peripheral blood mononuclear cells (PBMC), obtained from healthy platelet donors. PBMC were stimulated with phytohemagglutinin (PHA) for 72 hours and tested against 3 different WJ-MSC to measure suppression of T cell proliferation. The experiments were performed using passages P5 and P10. Analyses were done by real-time PCR, western blot, and flow cytometry. RESULTS: Our results show that gene expression and secretion of immunomodulatory molecules varied among WJ-MSC samples with no specific pattern discernible. In co-culture all WJ-MSC were capable of inhibiting mitogen-activated CD3+ T cell proliferation, although to different extents and each PBMC responded with its unique level of inhibition. In addition, the immunomodulatory profile of each WJ-MSC sample was essentially maintained even after several passages. CONCLUSION: Our results indicate that each WJMSC displays a unique behavior, differing in patterns of cytokine mRNA expression and immunomodulatory capacity. The intrinsic variability between samples may influence the effectiveness of WJ-MSC when employed therapeutically

Orientador: Ana Maria Segall Correa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-10T13:52:08Z (GMT). No. of bitstreams: 1 Nejar_FabiolaFigueiredo_D.pdf: 2860289 bytes, checksum: 520efe4425aa2a5d56c60de1053695d8 (MD5) Previous issue date: 2007 / Resumo: O presente estudo analisou os fatores associados à anemia infantil e materna, tempo de clampeamento do cordão umbilical e duração do aleitamento materno exclusivo. Utilizou-se uma coorte com 513 crianças, selecionadas no Hospital Estadual de Sumaré, avaliadas em dois momentos (parto/alta e seguimento aos 150 dias). Encontramos 16,9% das mulheres que apresentaram anemia durante a gestação, porém essa proporção é bem menor após 150 dias do parto (1,7%). Já a análise do sangue de cordão mostrou apenas 2,1% de exames com hemoglobina menor que 11g/dl e, aos 150 dias de vida da criança, encontramos 49% de anemia. Sobre o tempo de clampeamento do cordão encontramos um tempo médio de 18,5 segundos, sendo que apenas 3,7% dos clampeamentos aconteceram com mais de um minuto. Sobre o padrão de aleitamento materno os dados mostram que 72,9% mamavam no peito, porém de maneira exclusiva essa proporção é de 6,1%. A presença de leite materno de forma exclusiva teve ação protetora contra anemia ferropriva nas crianças estudadas. Consumir alimentos da família também comprometeu o nível de hemoglobina da criança. Observamos associação entre anemia nas crianças aos 150 dias de vida e prematuridade e/ou baixo peso ao nascer. Diversos estudos epidemiológicos demonstram a forte relação entre tempo de clampeamento do cordão umbilical e a concentração de hemoglobina, contudo neste estudo não encontramos esta associação provavelmente pelo pequeno número de casos de clampeamento com tempo adequado (maior ou igual a 1 minuto) / Abstract: The aim of this study was to analyze the associ ation of infant anemia and anemia of the mother, length of umbilical cord clamping and length of exclusive breastfeeding. A cohort of 513 infants pairs recruited in Sumare Hospital were followed-up to 6 months of age, with hematological evaluations at delivery and at age of 150 days after birth. Mother interviews were performance at the day before hospital discharge and at 150 days after delivery. At delivery there were 16.9% mothers with anem ia, decreasing 150 days later to 1.7%. Just 2.1% of umbilical cord blood analyses had hemoglobin lower than 11g/dl and at 150 days of life 49% of infants had anemia. The mean length of clamping was 18.5 seconds and in just 3.7% was over 1 minute. At the 150 day, there was 72.9% of breast feeding but just 6,1 was exclusive. Infant anemia at 150 days was associated to prematur ity and /or low weight at birth. Several epidemiological studies point out a strong association between length of clamping and the hemoglobin concentration, but this research failed to observe this association provably due to the small number of cases with sufficient length of clamping.The high prevalence of infant anemia demands that the clamping length must be equal or greater than 1 minute, and observed by all hospital in our region / Doutorado / Epidemiologia / Doutor em Saude Coletiva

Objetivo: Determinar a influência da presença de cafeína no sangue de cordão umbilical na ocorrência de apneia. Métodos: Estudo de coorte prospectivo de recém-nascidos pretermos com peso de nascimento menor de 2.000 g. Os critérios de exclusão foram: mães que receberam opióides , ventilação mecânica durante os primeiros 4 dias de vida, malformação congênita cerebral e cardíaca maiores, asfixia perinatal, hemorragia peri-intraventricular severa, exsanguíneotransfusão antes do quarto dia de vida e uso de metilxantina antes da extubação. Os recém-nascidos foram divididos em: com e sem cafeína detectável no sangue de cordão umbilical e acompanhados nos primeiros quatro dias de vida para a ocorrência de apneia. Resultados: 87 com e 40 sem cafeína detectável no sangue de cordão umbilical foram estudados. A mediana da concentração de cafeína dos 87 pacientes com cafeína detectável no sangue de cordão umbilical foi 2,3 µg/ml (0,2-9,4 µg/ml). Não houve associação entre a ocorrência de apneia e a presença de cafeína no sangue de cordão umbilical. Recém-nascidos com cafeína detectável no cordão umbilical tiveram apnéia mais tarde (66.3 horas) do que aqueles com níveis indetectáveis (54.2 horas). Conclusão: a detecção de níveis de cafeína no sangue de cordão umbilical não diminuiu a ocorrência de apneia da prematuridade. Nós sugerimos que novos estudos com a administração de altas doses de cafeína para mães antes do parto prematuro, como estratégia para prevenir a apneia da prematuridade, devam ser realizados. / Objective: To determine the influence of presence of caffeine in umbilical cord blood on apnea occurrence. Methods: A prospective cohort study with preterm newborns with birth weight less than 2,000 g was undertaken. Exclusion criteria were: mothers that received opioids, mechanical ventilation during the first 4 days of life, cerebral and major cardiac malformations, perinatal asphyxia, severe periintraventricular hemorrhage, exchange transfusion before the fourth day of life, and those that received methylxantine prior to extubation. Neonates were divided in: with detectable and undetectable caffeine in umbilical cord blood. Newborns were followed for the first 4 days for occurrence of apnea spells. Results: 87 with and 40 without detectable caffeine in umbilical cord blood were studied. The median caffeine concentration of the 87 patients with detectable caffeine in umbilical blood was 2.3 µg/ml (0.2-9.4 µg/ml). There was no association between occurrence of apnea spells and presence of caffeine in umbilical cord blood. Neonates with detectable caffeine in umbilical blood had apnea later (66.3 ± 4.14 hours) than those with undetectable levels (54.2 ± 6.26 hours). Conclusion: The detected levels of caffeine in umbilical cord blood did not decrease the occurrence of apnea of prematurity. We suggest that further studies on administration of high dose of caffeine to mothers prior to a preterm delivery as a preventive measure for apnea of prematurity deserve to be conducted.

A injúria renal aguda representa um estado de senescência precoce induzida por estresse, e as células-tronco mesenquimais podem ser uma alternativa para seu tratamento. Células-tronco jovens reduzem o fenótipo de envelhecimento em rins quando comparadas a células idosas. O objetivo deste estudo foi avaliar se o tratamento com jovens células-tronco mesenquimais derivadas de cordão umbilical humano podem interferir na senescência renal induzida por lesão de isquemia-reperfusão em ratos. Ratos machos foram submetidos ao modelo de isquemia de artérias renais bilateralmente por 45 minutos, com reperfusão após, e alguns animais receberam 1 X 106 células por via intraperitoneal após 6 horas da indução da lesão. Os animais foram eutanasiados no segundo ou no sétimo dia pós-isquêmico. No segundo dia após a lesão de isquemia-reperfusão, o tratamento com as células melhorou a filtração glomerular e a função tubular, melhorou a expressão renal de aquaporina-2 e reduziu a infiltração de macrófagos nos rins. Proteínas relacionadas à senescência (-galactosidase, p21, p16 e fator de transformação do crescimento ) e microRNAs (mir-29a e miR-34a) estiveram com a expressão aumentada após a isquemia-reperfusão, e houve redução nesses parâmetros com o tratamento. A redução na expressão de Klotho e o estado pró-oxidativo gerados pela isquemia-reperfusão também foram revertidos pelo tratamento. A senescência induzida pela injúria renal aguda é um processo independente de telômeros. Ao sétimo dia pós-lesão, os ratos isquêmicos mantinham defeito de concentração urinária, que foi revertido nos animais tratados. Além disso, o tratamento reduziu o índice de necrose tubular aguda em tecido renal e reduziu o infiltrado macrofágico túbulo-intersticial. O marcador pró-senescência p16 foi completamente restabelecido nos animais tratados. Nossos dados demonstram que o tratamento com jovens células-tronco mesenquimais derivadas de cordão umbilical humano atenua a resposta inflamatória e de estresse oxidativo que ocorre na injúria renal aguda, e reduz a expressão de proteínas e microRNAs relacionados à senescência. Nossos achados expandem as perspecivas para o tratamento da injúria renal aguda / Acute kidney injury represents a status of premature stress-induced senescence, and mesenchymal stem cells are an alternative for treatment. Young stem cells reduce aging phenotype in kidneys when compared to old cells. The objective of this study was to evaluate if treatment with young human umbilical cord mesenchymal stem cells could interfere in kidney senescence induced by renal ischemia-reperfusion in rats. Male rats were induced to ischemia-reperfusion injury by 45-minutes clamping of both renal arteries; some rats received 1X106 cells intraperitonally six hours later. Rats were euthanatized on post-renal ischemia reperfusion days two and seven. At day 2 after ischemia-reperfusion injury, treatment with cells improved glomerular filtration, tubular function, improved renal expression of aquaporin 2 and decreased macrophage kidney infiltration. Senescence-related proteins (?-galactosidase, p21, p16 and transforming growth factor ?) and microRNAs (miR-29a and miRNA-34a) were overexpressed after ischemia-reperfusion, and reversed by the treatment. The Klotho reduced expression and the pro-oxidative status induced by ischemia-reperfusion were reversed by the treatment. Senescence induced acute kidney injury is a telomere-independent process. At day 7, ischemic rats maintained urinary concentrating defect, which is reversed in treated animals. Moreover, treatment decreased the index of acute tubular necrosis in kidney tissue and decreased macrophage kidney infiltration. Senescence marker p16 was completely restored in treated animals. Our data demonstrate that young human umbilical mesenchymal stem cells treatment attenuates the inflammatory and oxidative stress response occurring in acute kidney injury, and reduces the protein and microRNA expression related to senescence. Our findings broaden the perspectives for the treatment of AKI

RESUMO BALDISSERA, J.L.C. Avaliação das diferentes metodologias de realização do ensaio clonogênico e validação do método de criopreservação e ressuspensão do sangue de cordão umbilical e placentário criopreservado. 2015, 78 f. Dissertação. Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 2015. O sangue de cordão umbilical e placentário (SCUP) tem sido utilizado como fonte de célulastronco hematopoéticas (CTHs) para transplante. A qualidade desse produto pode ser afetada durante as várias etapas do seu processamento. Neste estudo, foi avaliada a melhor metodologia de preparo da amostra para a realização do ensaio clonogênico (pura, diluída ou lavada) e validado o método de criopreservação e de ressuspensão das bolsas de SCUP. Foi avaliada também a funcionalidade da enzima aldeído desidrogenase (ALDH) como método para determinar a função das CTHs do SCUP, em 15 unidades criopreservadas pelo Laboratório de Criobiologia e Terapia Celular do Centro de Hematologia e Hemoterapia de Santa Catarina (HEMOSC). As unidades foram descongeladas em quatro etapas. O conteúdo dos segmentos e da bolsa foi coletado e ressuspenso com solução de albumina 5%, ACD 5% e solução fisiológica. A suspensão celular obtida foi utilizada para realização do ensaio clonogênico, avaliação da viabilidade celular, quantificação das células nucleadas (CN), CD34+ e das ALDH br . Os parâmetros tempo, custo e o resultado do ensaio clonogênico, utilizados para avaliar a metodologia, indicaram que a suspensão celular diluída é o melhor método a ser utilizado para a realização do ensaio clonogênico. A quantificação das CN e das células CD34+ totais pré-criopreservação e pós-criopreservação/descongelamento foi 8,3 (±1,9) x 10 8 e 8,2 (±2,0) x 10 8 (p = 0,3388) e 3,3 (±2,7) x 10 6 e 3,2 (±2,1) x10 6 (p = 0,4455), respectivamente. A quantificação das CN e das células CD34+ viáveis pré-criopreservação e pós-criopreservação/descongelamento foi 8,1 (±1,9) e 6,3 (±1,7) x 10 8 (p < 0,0001) e 3,27 (±2,0) x 10 6 e 2,8 (±1,8) x 10 6 (p = 0,0063), respectivamente. A porcentagem de células nucleadas e CD34+ viáveis no segmento proximal e na bolsa de 20 mL foi, respectivamente, 66,3 (±11,8) e 75 (35-93); 76,5 (±11,6) e 89 (75-100). No ensaio clonogênico foi observado crescimento médio de 31,8 (±7,6) unidades formadoras de colônias granulócito-macrófago (CFU-GM) x 10 5 CN plaqueadas obtidas da bolsa pós-criopreservação/descongelamento. Não foi encontrada correlação entre as células ALDH br /CD45 + viáveis e a quantificação das CFUGM ou das células CD34+ viáveis da bolsa pós-criopreservação/descongelamento. O coeficiente de correlação entre as células nucleadas e as células ALDEFLUOR bright da bolsa e do segmento pós-criopreservação/descongelamento foi (r) = 0,9399 com p < 0,0001 e (r) = 0,5478 com p = 0,0426, respectivamente. Foi encontrada correlação entre quantificação das células CD34+ e das CFU-GM da bolsa e do segmento pós-criopreservação/descongelamento. Esses dados indicam que o método utilizado para a realização da criopreservação e o descongelamento das unidades de SCUP encontra-se validado, e que o segmento pode ser utilizado como uma ferramenta de controle de qualidade para a seleção da unidade de SCUP para transplante. Palavras-chave: Validação. Sangue de cordão umbilical e placentário. Aldefluor. Célulastronco hematopoéticas. / ABSTRACT BALDISSERA, J.L.C. Evaluation of different methods of performing clonogenic assay and validation of the method of cryopreservation and resuspension of cryopreserved umbilical cord and placental blood. 2015. 78 f. Master Dissertation. Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 2015. Umbilical cord and placental blood (UCPB) has been used as a source of hematopoietic stem cells (HSCs) for transplant. The quality of this product may be affected during the various stages of processing it. In this study, the author reviewed the best preparation methodology for performing the clonogenic assay (pure, diluted or washed) and validated the method of cryopreservation and resuspension of UCPB bags. The author also evaluated the functionality of the aldehyde dehydrogenase enzyme (ALDH) as a method to determine the function of umbilical cord and placental blood HSCs, in 15 cryopreserved units by the Laboratory of Cryobiology and Cell Therapy of the Center for Hematology and Hemotherapy of Santa Catarina (HEMOSC). The units were thawed in four steps. The content of the segments and the bag was collected and resuspended in a 5% albumin solution, 5% acid ci trate dextrose and saline solution. The cell suspension obtained was used to conduct the clonogenic assay, the assessment of cell viability, the quantification of nucleated cells (NC), CD34 + and ALDH br . The parameters of time, cost and the result of the clonogenic assay, used to evaluate the methodology, indicated that the diluted cell suspension is the best method to be used when performing a clonogenic assay. The quantification of the nucleated cells (NC) and the total CD34+ cells pre-cryopreservation and post-cryopreservation/thawing was 8,3 (±1,9) x 10 8 and 8,2 (±2,0) x 10 8 (p = 0,3388) and 3,3 (±2,7) x 10 6 and 3,2 (±2,1) x10 6 (p = 0,4455), respectively. The quantification of the NC and CD34+ viable cells pre-cryopreservation and post-cryopreservation/thawing was 8,1 (±1,9) and 6,3 (±1,7) x 10 8 (p < 0,0001) and 3,27 (±2,0) x 10 6 and 2,8 (±1,8) x 10 6 (p = 0,0063), respectively. The percentage of viable nucleated cells and CD34+ viable cells in the proximal segment and in the 20mL bag was 66,3 (±11,8) and 75 (35-93); 76,5 (±11,6) and 89 (75-100), respectively. In the clonogenic assay an average growth of 31,8 (± 7,6) colony-forming granulocyte-macrophage units (CFUGM) x 10 5 NC plated, obtained from the post-cryopreservation/thawing bag was observed. No correlation between the ALDH br /CD45 + viable cells and the quantification of CFU-GM or CD34+ viable cells obtained from the bag post cryopreservation was found. The coefficient of correlation between nucleated cells and ALDEFLUOR bright cells from the bag and segment after cryopreservation were (r) = 0, 9399 with p < 0, 0001 and (r) = 0, 5478 with p = 0,0426, respectively. A correlation between quantification of CD34+ cells and CFU-GM bag and segment cells after cryopreservation/thawing was found. This data indicates that the method used to perform the cryopreservation and thawing of the UCPB unit has been validated, and that the segment can be used as a tool for quality control when making the selection of UCPB for transplant. Keywords: Validation. Umbilical cord and placental blood. Aldefluor. Hematopoietic stem cells.

Diabetes mellitus (DM) designa um conjunto de patologias devidas à falta ou ação deficiente da insulina. O DM1 é causado por ataque auto-imune às células &#946;-pancreáticas secretoras de insulina, enquanto DM2 é relacionado com idade e obesidade. Alotransplante de pâncreas ou de ilhotas são alternativas terapêuticas, mas escassez de órgãos e necessidade de imunossupressão são obstáculos importantes. Células-tronco, isoladas da massa interna de blastocistos e de tecidos adultos, são capazes de auto-renovação e diferenciação, podendo ser utilizadas para o tratamento de doenças. Os objetivos deste trabalho foram: a) buscar novos genes envolvidos no processo de diferenciação de células tronco em células secretoras de insulina e b) isolar e caracterizar células-tronco mesenquimais humanas. Células-tronco embrionárias murinas foram induzidas a se diferenciar em clusters similares a ilhotas. O RNA foi utilizado para sondar microarrays de DNA (CodeLink) e os genes diferencialmente expressos foram confirmados por Q-PCR, sendo possível identificar 16 novos genes associados à diferenciação. Dois tipos diferentes de células-tronco mesenquimais foram isoladas da veia (MSC) e do sangue (UCB) de cordão umbilical humano. Imunofenotipagem e caracterização molecular por Q-PCR, apontaram para a existência de dois tipos diferentes de progenitoras mesenquimais adultas no cordão umbilical humano. / Diabetes mellitus (DM) defines a number of pathologies caused by the lack or deficient action of the insulin hormone. DM1 is caused by an auto-immune attack to insulin secreting &#946;-pancreatic cells, while DM2 is related to ageing and obesity. Pancreas and islet allo-transplantation constitute therapeutic alternatives, but severe organ shortage and the absolute requirement for immunossupression still constitute important obstacles. Stem cells isolated from the blastocist inner cell mass and from adult tissues are capable of self-renewal and differentiation, and may be utilized for treatment of several diseases. The objectives of this work were: a) to search for new genes involved in the process of differentiation of stem cells into insulin-secreting cells and b) to isolate and characterize mesenchymal stem cells. Murine embryonic stem cells were induced to differentiate in islet-like clusters. Total RNA was utilized to probe DNA microarrays (CodeLink) and the differentially expressed genes were confirmed by Q-PCR, with 16 new genes being identified as associated with differentiation. Two different types of mesenchymal stem cells were isolated from human umbilical cord vein (MSC) and blood (UCB). Immunophenotyping and molecular characterization by Q-PCR, pointed to the existence of two different types of progenitor mesenchymal stem cells in human umbilical cord.

South Africa is in dire need of a public umbilical cord blood stem cell bank (UCB SCB). A severe shortage of genetically compatible samples for BM transplantation precludes the majority of South Africans from receiving the relevant medical care. UCB is a viable alternative to BM but is currently disposed of post-delivery. UCB could furthermore serve as a resource of genetically compatible haematopoietic progenitor cells (HPCs) that could be used in gene therapy approaches directed towards a cure for HIV-1. Knowing whether HIV-1 affects or infects primitive HPCs is vital to determine the course of action for transplantation of UCB-derived genetically resistant HPCs. Collecting and storing UCB in a public UCB bank could thus serve as a vital resource of genetically compatible samples for BM transplantation. It was thought that the high incidence of HIV-1 in South African patients and the persistent stigma surrounding HIV-1 would be problematic for collecting sustainable numbers of UCB units and subjecting units to compulsory screening for infectious diseases. This was however, not the case. In the South African context, we are faced with unique and rich challenges relating to cultural and religious differences that are further augmented by linguistic constraints and educational insufficiencies. Nevertheless, the majority of patients within the interviewed patient cohort were supportive of the idea of establishing a public UCB SCB in SA and were willing to undergo additional HIV-1 screening. The Ultrio-Plus® assay was verified in this study for screening UCB units for HIV-1 and could be used in routine analyses of UCB units prior to banking. Conflicting results in the literature exist with regard to HIV-1’s ability to infect or affect haematopoietic progenitor cells. Results from this study revealed that HIV-1 was not only able to affect HPCs’ ability to form colonies in vitro, but was also capable of infecting CD34+ HPCs in some individuals. These results substantiate the theory that some CD34+ HPCs serve as viral reservoirs which could account for residual viraemia in patients on antiretroviral therapy. Results suggest that allogeneic transplantation of HIV-1 infected individuals with UCB-derived, genetically modified HPCs, should be pursued. / Thesis (PhD)--University of Pretoria, 2012. / Immunology / unrestricted

Type 1 Diabetes (T1D) is organ-specific autoimmune disease which causes pancreatic beta cells to be irreversibly destroyed. The only possible treatment represents life-lasting insulin administration. The real trigger of destructive insulitis isn't known. T1D is a multi- factorial disease involving both external and internal factors in the disease pathogenesis. The presence of autoreactive T lymphocytes in pancreas is necessary for development of diabetes. T regulatory cells have protective function in the destructive insulitis. The aim of this diploma thesis was to study cord blood T regulatory cells and their connection to type 1 diabetes development. We tried to find the difference among T regulatory cells in mononuclear cord blood cells (CBMC) in different study groups. Samples were collected from mothers suffering from T1D, gestational diabetes. Healthy controls were tested as well. Sixty-eight samples of cord blood were included in the study among the years 2009 - 2011. Samples were divided into 3 groups (CBMC from children born to T1D mothers, mothers with gestational diabetes and healthy mothers without T1D). CBMC were ana- lysed by flow cytometry. T regulatory cells (defined as CD4+CD25+) were isolated by magnetic separation (MACS). The functional capacity of these cells was studied as well by...

Eine Erhöhung des Bilirubins über 2 mg/dl betrifft 90 % aller Neugeborenen. Sie ist meist physiologisch und tritt optisch sichtbar bei 60-70 % dieses Kollektivs auf. In der pathologischen, exzessiv erhöhten Form ist sie der häufigste Grund für eine stationäre Wiederaufnahme während der ersten sieben Lebenstage. Ihre schwerste Komplikation, der Kernikterus, scheint - trotz allgemein verfügbarer, preiswerter und sicherer Therapiemöglichkeiten - wieder vermehrt aufzutreten. Die Gründe liegen im Überwachungsdefizit bei früher Entlassung von schlecht aufgeklärten Eltern, Nichtbeachtung der Besonderheiten der Neugeborenen ≤ 38 Schwangerschaftswochen und der zunehmenden Tendenz zum Stillen bei häufig unzureichender Anleitung. Ferner werden ikterische Kinder nur zu oft lediglich visuell bezüglich des Grades der Bilirubinämie eingeschätzt und die Therapie somit erheblich verzögert. Gegenstand dieser Arbeit ist die Frage, ob aus der Dynamik des Serumbilirubinspiegels von der Geburt bis zum 3. Lebenstag die Wahrscheinlichkeit des Auftretens einer phototherapiepflichtigen Hyperbilirubinämie abgeschätzt werden kann. Dazu wurde der Serumbilirubinspiegel direkt postnatal aus dem Nabelschnurblut, bzw. am 3. Lebenstag gleichzeitig mit dem Stoffwechselscreening ermittelt und der Phototherapiebedarf im Verlauf festgehalten. Um die Aussage zu präzisieren, wurde die Studienpopulation aus 2573 Kindern weiter unterteilt in 2180 reife tAGA- (hier Eu- und Hypertrophe), 267 reife tSGA-Kinder (Hypotrophe) und 126 FG (Frühgeborene). In allen 3 Gruppen korrelierten das Nabelschnurbilirubin und der Serumbilirubinwert vom 3. Lebenstag positiv mit der Entwicklung einer Hyperbilirubinämie. Anhand dieser Ausgangswerte konnten Grenzen für Hoch-, Mittelhoch-, Mittelniedrig- und Niedrigrisikogruppen definiert werden, welche die Entwicklung einer Hyperbilirubinämie mit einer Wahrscheinlichkeit von ≥ 20 %, 5-20 %, 0 < x <5 % und 0 % voraussagen. Damit kann man bereits früh eine Vorabselektion entsprechend dem Gefährdungspotential treffen und die Verlaufskontrollen entsprechend terminieren. Als Risikofaktoren einer therapiepflichtigen Hyperbilirubinämie wurden außerdem Frühgeburtlichkeit, seltener tSGA, geringes Geburtsgewicht und niedriges Gestationsalter (in der vorliegenden FG-Gruppe nicht signifikant) gefunden. Im Falle einer Sectiogeburt und bei Zuhilfenahme von Hilfsmitteln im Rahmen einer vaginalen Entbindung nahm der Bedarf an Phototherapie in der tAGA- und tSGA-Gruppe zu.:Bibliographische Beschreibung……………………………………………………………………….1 Abkürzungsverzeichnis………………………………………………………………………………..2 1. Einleitung…………………………………………………………………………………...3 1.1. Geschichtliche Entwicklung……………………………………………………………………...3 1.2. Wandel der Anschauungen zu den Therapiegrenzen…..…………………………….................4 1.3. Hyperbilirubinämie……………………………………………………………………………….7 1.4. Kernikterusregister………………………………………………………………………………..8 1.5. Problemstellung…………………………………………………………………………………...9 2. Patienten und Methoden………………………………………………………………..11 2.1. Patientenkollektiv………………………………………………………………………………...11 2.2. Ausschlusskriterien………………………………………………………………………………11 2.3. Datenerfassung………………………………………………………………………………...…11 2.4. Phototherapie (PT)………………………………………………………………………………12 2.5. statistische Analyse………………………………………………………………………………13 2.5.1. konkrete Fragestellung………………………………………………………………………………...…13 2.6. Signifikanzniveau……………………………………………………..………………………….13 3. Ergebnisse………………………………………………………………………………..14 3.1. Gesamtpopulation…………………………………………………………….………………….14 3.2. Charakteristika der Studienpopulation…………………………….…………………………..14 3.3. tAGA (reife eu- und hypertrophe Neugeborene)………………………………………………16 3.4. tSGA (reife hypotrophe Neugeborene).……….……………………………………………….18 3.5. Frühgeborene (FG)………………………………..…………………………….……………….20 3.6. direkter Vergleich der 3 Untergruppen (tAGA, tSGA und FG)…………………………...…22 3.7. Charakteristika der Population der zweiten Studienphase…………………………………...28 3.8. tAGA-Kinder in der zweiten Studienphase (TSB3-tAGA)……………………………………30 3.9. tSGA in der zweiten Studienphase (TSB3-tSGA)….…………………………………………..32 3.10. Frühgeborene in der zweiten Studienphase (TSB3-FG)……………….…………………….35 3.11. direkter Vergleich der drei Untergruppen der zweiten Studienphase…………….………..37 3.12. Vergleich der retro- und prospektiven Teile der Studie…….……………………………….43 3.13. Die Phototherapiegruppe………………………………………………………………………45 3.13.5. Zusammenhang zwischen Phototherapie und Geburtsmodus………………………………………..47 3.13.6. Zusammenhang zwischen Phototherapie und Nabelschnurbilirubin………………………………..48 3.13.7. Zusammenhang zwischen Phototherapie und Serumbilirubin vom 3.LT (TSB3)…………………..51 3.14. Vorhersage der therapiepflichtigen Hyperbilirubinämie anhand der Nabelschnurbilirubin-Werte…..………………………………………………….…………………………………….……..54 3.14.1. statistische Begriffe………………………………………………………………………………………54 3.14.2. Vorhersage der therapiepflichtigen Hyperbilirubinämie anhand der Nabelschurbilirubin-Werte.54 3.15. Vorhersage der therapiepflichtigen Hyperbilirubinämie anhand TSB3 (Serumbilirubin vom 3. Lebenstag)……………………...………………………………………..……………………56 3.16. Zusammenhang zwischen NS-Bili und TSB3(Serumbilirubin vom 3. Lebenstag)…………58 3.17. Regressionsanalyse…………………………………...…………………………………………59 3.17.1. univariate Regressionsanalyse………………………………………………………………………….59 3.17.2. multivariate Regressionsanalyse………………………………………………………………………..59 3.18. Odds Ratio einer therapiepflichtigen Hyperbilirubinämie………………………………….61 3.19. Beginn und Dauer der Phototherapie…………………………………………………………62 4. Diskussion……………………………………….…………………………………..…….64 Nabelschnurbilirubin und Phototherapie………………………………………………….……….64 Serumbilirubin vom 3. Lebenstag und Phototherapie….………………………………………….67 Kombination aus Nabelschnurbilirubin und Serumbilirubin vom 3.Lebenstag…………………71 Phototherapiegruppe…………………………………………………………………………………73 Schlussfolgerung…………………………...…………………………………………………………76 5. Zusammenfassung der Arbeit……………………………………………………………78 6. Literaturverzeichnis………………………………………………………………………82 7. Abbildungsverzeichnis……………………………………………………………………98 8. Tabellenverzeichnis……………………………………………………………………….99 Erklärung über die eigenständige Abfassung der Arbeit…………………………..……101 Danksagung…………………...…………………………………………………..………..102 Lebenslauf……………………………………………………………………………………………103