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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

Characterization of Proteins Released by Osteoblasts That Promote Expansion of Hematopoietic Progenitors

Hovey, Owen 22 August 2018 (has links)
Umbilical cord blood (UCB) is a source of hematopoietic stem and progenitor cells (HSPC) used for allogeneic transplantation. Ex vivo expansion of HSPC can improve the slow platelet and neutrophil engraftment associated with UCB transplants. HSPCs reside in niches, some of which are near the endosteal bone surface, where they can associate with immature osteoblasts. Interestingly, osteoblasts can enhance the growth of HSPC in culture and their platelet engraftment activity. Using a proteomics approach, I identified 47 differentially expressed proteins between mesenchymal stem cells and immature osteoblasts. Several of these were previously implicated in HSPC maintenance such as IGF2, IGFBP2, DCN, GAS6 and VCAM1. Moreover, several other proteins belong to the alternative and classical complement pathways. Finally, I discovered that microvesicles found in osteoblast conditioned medium may also modulate the growth of HSPC, at least in ex vivo cultures.
12

Imunofenotipagem de subpopulações de linfócitos-T no sangue do cordão umbilical de eqüinos

Godoy, Roberta Ferro de [UNESP] 13 June 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-06-13Bitstream added on 2014-06-13T20:41:25Z : No. of bitstreams: 1 godoy_rf_dr_jabo.pdf: 1788688 bytes, checksum: 4ccc9b3b87b86597a8dc9255e154fe46 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Apesar da importância do sangue do cordão umbilical (SCU) como fonte de células tronco e do advento da imunofenotipagem de linfócitos, não existem estudos sobre a imunofenotipagem de linfócitos do sangue do cordão umbilical eqüino. Este estudo visou determinar os valores eritroleucométricos e quantificar as subpopulações de linfócitos-T no SCU e no sangue obtido por venipunção da jugular de eqüinos neonatos da raça Brasileiro de Hipismo. Para tanto, foram realizadas as colheitas de SCU e da jugular de 20 potros ao nascimento. As amostras foram submetidas às determinações dos valores eritroleucométricos e à quantificação de subpopulações de linfócitos-T, pela técnica citofluorométrica. Não foram verificadas diferenças significativas (p>0,05) entre os valores médios obtidos para tais parâmetros quando comparados o sangue central e o SCU de neonatos eqüinos. Os valores eritrométricos encontrados no SCU e da jugular de neonatos equinos, exceto o VCM, se situaram na faixa de normalidade para animais adultos e foram inferiores aos valores reportados para eqüinos neonatos. O valor absoluto para neutrófilos segmentados, no SCU e no sangue da jugular dos neonatos, foi inferior ao reportado para eqüinos ao nascimento. As contagens de linfócitos CD5+ e CD4+ no SCU e jugular de neonatos eqüinos foram inferiores àquelas reportadas para o sangue periférico de eqüinos adultos, indicando um componente imunológico imaturo. No entanto, a contagem de linfócitos CD8+ foi semelhante à reportada para o sangue periférico de eqüinos adultos. A proporção CD4:CD8 obtida neste ensaio, tanto para o SCU (2,64l0,91) quanto para o sangue obtido por venipunção jugular (2,41l0,81), em eqüinos neonatos demonstrou dominância das células T CD4+ sobre os linfócitos T CD8+. / Although the importance of umbilical cord blood as source of stem cells and the advent of Iymphocytes immunophenotyping, no studies have been performed on the immunophenotyping of equine UCB Iymphocytes. The objective of the present work was to determine erythrometric and leukometric values and quantify subpopulations of Iymphocytes in UCB and jugular blood of neonatal horses. UCB and jugular blood were collected from 20 foals of the Brasilian of Hipism breed at birth and processed for determination of erythrometric and leukometric values and quantification of subpopulations of T Iymphocytes by cytofluorometry. No significant difterences (p<0.05) were observed between average values in jugular blood of neonates and UCB of horses. Erythrometric values, except for mean corpuscular volume (MCV), were within the normal range seen in adult animais and below those reported for foal's circulating blood. Total values observed for segmented neutrophils in UCB and jugular blood of neonates were below those reported for horses at birth. CD5+ and CD4+ Iymphocytes were in lower frequencies in UCB and jugular blood of neonates than in peripheral blood of adult horses, indicating an immature immunological component. The frequency of CD8+ Iymphocytes, however, was similar to that described for the peripheral blood of adult horses. The CD4:CD8 proportion observed in the present study, for UCB (2.64:1:0.91) as well as for neonatal jugular blood (2.41:1:0.81), showed predominance of CD4+ T cells over CD8+ T Iymphocytes.
13

Imunofenotipagem de subpopulações de linfócitos-T no sangue do cordão umbilical de eqüinos /

Godoy, Roberta Ferro de. January 2006 (has links)
Orientador: Aureo Evangelista Santana / Banca: Ana Paula Massae Nakage Canesin / Banca: Maria Angélica Dias / Banca: Márcia Rita Fernandes Canola / Banca: Julio Carlos Canola / Resumo: Apesar da importância do sangue do cordão umbilical (SCU) como fonte de células tronco e do advento da imunofenotipagem de linfócitos, não existem estudos sobre a imunofenotipagem de linfócitos do sangue do cordão umbilical eqüino. Este estudo visou determinar os valores eritroleucométricos e quantificar as subpopulações de linfócitos-T no SCU e no sangue obtido por venipunção da jugular de eqüinos neonatos da raça Brasileiro de Hipismo. Para tanto, foram realizadas as colheitas de SCU e da jugular de 20 potros ao nascimento. As amostras foram submetidas às determinações dos valores eritroleucométricos e à quantificação de subpopulações de linfócitos-T, pela técnica citofluorométrica. Não foram verificadas diferenças significativas (p>0,05) entre os valores médios obtidos para tais parâmetros quando comparados o sangue central e o SCU de neonatos eqüinos. Os valores eritrométricos encontrados no SCU e da jugular de neonatos equinos, exceto o VCM, se situaram na faixa de normalidade para animais adultos e foram inferiores aos valores reportados para eqüinos neonatos. O valor absoluto para neutrófilos segmentados, no SCU e no sangue da jugular dos neonatos, foi inferior ao reportado para eqüinos ao nascimento. As contagens de linfócitos CD5+ e CD4+ no SCU e jugular de neonatos eqüinos foram inferiores àquelas reportadas para o sangue periférico de eqüinos adultos, indicando um componente imunológico imaturo. No entanto, a contagem de linfócitos CD8+ foi semelhante à reportada para o sangue periférico de eqüinos adultos. A proporção CD4:CD8 obtida neste ensaio, tanto para o SCU (2,64l0,91) quanto para o sangue obtido por venipunção jugular (2,41l0,81), em eqüinos neonatos demonstrou dominância das células T CD4+ sobre os linfócitos T CD8+. / Abstract: Although the importance of umbilical cord blood as source of stem cells and the advent of Iymphocytes immunophenotyping, no studies have been performed on the immunophenotyping of equine UCB Iymphocytes. The objective of the present work was to determine erythrometric and leukometric values and quantify subpopulations of Iymphocytes in UCB and jugular blood of neonatal horses. UCB and jugular blood were collected from 20 foals of the Brasilian of Hipism breed at birth and processed for determination of erythrometric and leukometric values and quantification of subpopulations of T Iymphocytes by cytofluorometry. No significant difterences (p<0.05) were observed between average values in jugular blood of neonates and UCB of horses. Erythrometric values, except for mean corpuscular volume (MCV), were within the normal range seen in adult animais and below those reported for foal's circulating blood. Total values observed for segmented neutrophils in UCB and jugular blood of neonates were below those reported for horses at birth. CD5+ and CD4+ Iymphocytes were in lower frequencies in UCB and jugular blood of neonates than in peripheral blood of adult horses, indicating an immature immunological component. The frequency of CD8+ Iymphocytes, however, was similar to that described for the peripheral blood of adult horses. The CD4:CD8 proportion observed in the present study, for UCB (2.64:1:0.91) as well as for neonatal jugular blood (2.41:1:0.81), showed predominance of CD4+ T cells over CD8+ T Iymphocytes. / Doutor
14

Transplante de sangue de cordão umbilical aparentado e não aparentado para pacientes com síndromes de insuficiência medular hereditárias, excluindo anemia Fanconi / Outcomes after related and unrelated umbilical cord blood transplantation for hereditary bone marrow failure syndromes other than Fanconi anemia

Bizzetto, Renata 17 August 2018 (has links)
Orientador: Carmino Antonio de Souza / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-17T18:40:20Z (GMT). No. of bitstreams: 1 Bizzetto_Renata_M.pdf: 5388324 bytes, checksum: 8344246752d17626b3442925d28a5b44 (MD5) Previous issue date: 2010 / Resumo: O transplante com células tronco hematopeticas é a única opção curativa para os pacientes com síndromes de insuficiência medular hereditárias (SIMH). O sangue de cordão umbilical é uma fonte alternativa de células tronco hematopoéticas para o transplante alogênico. Pacientes e métodos: Este estudo retrospectivo e multicêntrico é baseado em dados do registro Eurocord sobre pacientes com SIMH, excluindo os paciente com anemia de Fanconi, que receberam transplante de sangue de cordão umbilical (TCU). Resultados: Sessenta e quatro pacientes com SIMH foram transplantados com doador aparentado (n=20) e não aparentado (n=44). Os diagnósticos foram: anemia de Blackfan Diamond (21 pacientes), trombocitopenia amegacariocítica congênita (16 pacientes), disqueratose congênita (8 pacientes), síndrome de Shwachman-Diamond (2 pacientes), neutropenia congênita grave (16 pacientes) e SIMH inclassificável (1 paciente). No grupo aparentado, 19 pacientes receberam transplante HLA compatível do irmão. A mediana de células nucleadas totais (CNT) infundidas foi 5x107/kg. A incidência cumulativa da recuperação de neutrófilos em 60 dias foi 95%, 2 pacientes tiveram doença do enxerto contra hospedeiro (DECH) grau II a IV e a incidência cumulativa em 2 anos de DECH crônica foi 11%. A sobrevida global (SG) em 3 anos foi 95%. No grupo não aparentado, 86% dos pacientes receberam enxerto com incompatibilidade HLA e 3 receberam duas unidades de cordão umbilical. A mediana de CNT infundidas foi 6,1x107/kg. A incidência cumulativa da recuperação de neutrófilos em 60 dias foi 55%; de DECH grau II a IV em 100 dias foi 24% e de DECH crônica em 2 anos foi 53%. A SG em 3 anos foi 61%; melhor SG foi associada com idade < 5 anos (p=0,01) e número CNT infundidas ? 6.1x107/kg (p=0,03). Conclusão: em pacientes com SIMH, TCU aparentado é associado com excelentes resultados enquanto no TCU não aparentado o aumento no número de células promove melhoresresultados / Abstract: Background: Allogeneic stem cell transplantation is the only curative option for patients with hereditary bone marrow failure syndromes (HBMFS). Umbilical cord blood (UCB) cells is an alternative stem cell source for allotransplantation. Design and Methods: This multicenter, retrospective study is based on data reported to Eurocord Registry about patients with HBMFS other than Fanconi anemia who received UCB transplantation (UCBT). Results: Sixty four patients with HBMFS were transplanted from related (n=20) or unrelated donors (n=44). Diagnoses were: Diamond-Blackfan anemia (21 patients), congenital amegakaryocytic thrombocytopenia (16 patients), dyskeratosis congenita (8 patients), Shwachman-Diamond syndrome (2 patients), severe congenital neutropenia (16 patients) and unclassified HBMFS (1 patient). In the related group, all patients but one received an HLA-matched sibling transplant. Median total nucleated cells (TNC) infused was 5x107/kg. Cumulative incidence (CI) of 60-day neutrophil recovery was 95%, 2 patients had grade II-IV acute graft-versus-host disease (GVHD), while the 3-year CI of chronic GVHD was 11%. The 3-year overall survival (OS) was 95%. In the unrelated group, 86% of patients had HLA mismatched grafts and 3 received two UCB units. Median TNC infused was 6.1x107/kg. Day-60 CI of neutrophil recovery was 55%; 100-day CI of grade II-IV acute GVHD was 24%, while 2-year CI of chronic GVHD was 53%. The 3-year OS was 61%; better OS was associated with age < 5 years (p=0.01) and a number of TNC infused ? 6.1x107/kg (p=0.03). Conclusion: in patients with HBMFS, related UCBT is associated with excellent outcomes while in unrelated UCBT increasing cell dose might provide better results / Mestrado / Clinica Medica / Mestre em Clinica Medica
15

microRNA-184 Regulation of NFAT1 in Umbilical Cord Blood CD4<sup>+</sup> T-cells: Implications for Graft Versus Host Disease

Weitzel, Richard Patrick January 2010 (has links)
No description available.
16

Haematopoietic stem/progenitor cell interactions with the bone marrow vascular niche

Chang, Chao-Hui January 2013 (has links)
Umbilical cord blood (UCB) is used as a source of haematopoietic stem cells (HSCs) for transplantation but shows defective homing to the bone marrow niche and delayed haematological reconstitution. Following transplantation, HSCs will home to the bone marrow in response to the CXCL12 chemokine, adhere to the bone marrow sinusoidal endothelial cells and then migrate into and lodge in bone marrow niches. In addition to CXCR4, a variety of molecules have been described as being important in these processes. In this laboratory, junctional adhesion molecule-A (JAM-A) was shown to be expressed on human UCB CD133⁺/CD34⁺ cells and regulated by hypoxia. In this thesis, further phenotypic studies show that this molecule is most highly expressed on human CD41a⁺ megakaryocytes and CD14⁺ monocytes/macrophages in UCB. JAM-A was also found to be expressed on all human UCB CD133⁺ cells, which have been shown by others to encompass the HSCs and early myeloid-lymphoid precursors and on the majority of CD34⁺ haematopoietic progenitor cells (HPCs). While it is also present on bone marrow sinusoidal endothelium (BMEC), JAM-A is not detected on cultured bone marrow mesenchymal stromal cells (MSCs). JAM-A blockade, silencing and overexpression experiments showed that JAM-A contributes to, but is not solely responsible for, the adhesion of CD34⁺ haematopoietic progenitor cells to IL-1β activated BMEC-60 cells and fibronectin. Lack of significance in cell migration suggested that JAM-A is more likely to act as an adhesion molecule or a regulator of adhesion rather than as a migratory molecule in such cells. Further functional studies using the proximity ligation assay highlight a potential association of JAM-A with CXCR4 and the adhesion molecules, tetraspanin CD82 and integrin β1. Mechanistic studies were commenced to establish if JAMA could modulate CXCR4 signalling following CXCL12 stimulation, but time constraints prevented these from being completed. These preliminary experiments which were carried out first in the Jurkat cell line lacking JAM-A or transduced to express JAM-A, however, suggest that JAM-A may modulate CXCL12-induced Rap1 phosphorylation and ERK1/2 phosphorylation. The former pathway is important for integrin function and the latter pathway is important in cell adhesion. The results described here, although requiring finalisation, support the hypothesis that JAM-A acts as an adhesion molecule and also may fine tune CXCR4 and integrin mediated functions on human CD34⁺ cells, thereby potentially regulating engraftment of these cells to the bone marrow niche.
17

Caractérisation des cellules souches mésenchymateuses du sang placentaire et de la gelée de Wharton / Caracterization of mesenchymal stem cells from cord blood and Wharton's jelly

Margossian, Talar 25 March 2013 (has links)
Les cellules souches suscitent de grands espoirs pour la thérapie cellulaire et l'ingénierie tissulaire. Les CSM du tissus foetaux (sang placentaire et gelée de Wharton du cordon ombilical), à l'origine d'épiblaste embryonnaire, sont considérées comme plus primitives que les CSM provenant de sources adultes. Les conditions de culture ayant un impact sur le comportement des cellules, dans notre étude, nous avons exploré l'effet de la concentration de l'oxygène sur l'expansion, l'immunophénotypage et la différenciation de ces cellules. L'objectif de ce travail est d'identifier la méthode optimale d'isolation des CSM issues de tissus foetaux. Compte tenu du faible taux de succès dans l'isolement des CSM extraites du sang placentaire, nous nous sommes dirigés vers les CSM-GW. Nous y avons déterminé in situ, les marqueurs spécifiques exprimés dans la gelée de Wharton et à la périphérie. Des études sur la morphologie, la cinétique de croissance, et sur l'expression phénotypique des marqueurs de surface, des CSM-GW, ont été effectuées sur une longue durée (7 passages) à différentes conditions de culture. Nous avons montré que la GW est composée d'une abondante matrice extracellulaire riche en collagènes et glycosaminoglycannes et que les cellules possèdent un phénotype variable selon leur localisation dans la gelée. Ce tissu est capable de fournir une quantité importante de CSM (6,7x105 Cs/cm de cordon) qui gardent une morphologie constante. Enfin, quel que soit le passage, la concentration de l'oxygène ne semble pas avoir d'effet sur le phénotype des cellules. En revanche, une faible teneur en oxygène durant l'expansion semble diminuer le temps de doublement des cellules, favoriser la chondrogénèse et inhiber la différenciation ostéogénique. Enfin, quelles que soient les conditions de culture, la différenciation adipogénique des CSM-GW semble difficile à obtenir / Stem cells are the hopes for cell therapy and tissue engineering. MSCs from fetal tissue (umbilical cord blood and WJ), which are a source of embryonic epiblast grow relatively faster comparing to other adult sources. The culture condition can affect cell behavior. In our study, we explored the effect of oxygen concentration on the expansion, immunophenotyping, and differentiation of these cells. The aim of this work is to identify the optimal method for isolation of MSCs derived from fetal tissue. Given the low rate of success in the isolation of MSCs from cord blood, we headed to WJ-MSCs. We have determined in siu, the specific markers expressed in the WJ and in the perivascular region. Studies on the morphology growth kinetics, and phenotypic expression of surface makers of MSCs isolated from WJ were made over a long period (7 passages) in different culture conditions. We have shown that WJ is composed of an abundant extracellular matrix rich in collagen and glycasominoglycans and have variable phenotype depending from their localization in the jelly. This tissue is able to provide a large amount of MSCs (6.7x105 Cs/cm of cord) that maintain a constant morphology. Finally, regardless of the passage, the oxygen concentration does not effect on the phenotype of the cells. In contrast, a low oxygen concentration during expansion appears to decrease the doubling time of MSCs, promote chondrogenesis and inhibit osteogenic differentiation. Finally, whatever the culture conditions, adipogenic differentiation of WJ-MSC seems difficult to obtain
18

Estudos sobre o isolamento e expansão de células Natural Killer (NK) do sangue de cordão umbilical e placentário na presença de células mesenquimais

Furlan, Juliana Monteiro January 2016 (has links)
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.
19

Determinação dos níveis de cafeína no sangue de cordão umbilical de pré-termos e ocorrência de apnéia nos primeiros dias de vida

Hentges, Cláudia Regina January 2009 (has links)
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.
20

Estudos sobre o isolamento e expansão de células Natural Killer (NK) do sangue de cordão umbilical e placentário na presença de células mesenquimais

Furlan, Juliana Monteiro January 2016 (has links)
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.

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