Indiana University-Purdue University Indianapolis (IUPUI) / The entire hematopoietic system rests upon a group of very rare cells called hematopoietic stem cells (HSCs). Due to this extraordinarily crucial role, after birth HSCs are localized to the deep bone marrow niche, a hypoxic environment inside the bone where HSCs are under well-orchestrated regulation by both cellular and humoral factors. Among the cellular components regulating hematopoiesis are Leptin Receptor (LEPR)-expressing mesenchymal/stromal cells and adipocytes; both have been demonstrated to have significant influence on the maintenance of HSCs under homeostasis and in stress-related conditions. It has been reported in early work by others that HSCs and hematopoietic progenitor cells (HPCs) express LEPR. However, whether LEPR+ HSCs/HPCs are functionally different from other HSCs/HPCs was unknown. In this study, I demonstrated for the first time that murine LEPR+ Lineage-Sca-1+cKit+ (LSK, a heterogenous population consisting of HSCs/HPCs) cells even though constituting a small portion of total LSK cells are significantly enriched for both phenotypic and functional self-renewing long-term (LT) HSCs as shown in primary and secondary transplants in lethally irradiated recipients. LEPR+LSK cells are also more enriched for colony-forming progenitor cells assessed by colony-forming unit (CFU) assays. In addition, LEPR+ HSCs (defined as LSKCD150+CD48-) exhibited robust repopulating potential as compared to LEPR-HSCs in long-term competitive transplantation assays. To elucidate the molecular pathways that may govern functional properties of LEPR+HSCs, bulk RNA-seq on freshly sorted cells was done. Gene set enrichment analyses (GSEA) revealed Interferon Type I and Interferon γ (IFNγ) Pathways were significantly enriched in LEPR+HSCs while mitochondrial membrane protein gene set was significantly enriched in LEPR-HSCs. Interestingly, proinflammatory signaling including IFNγ pathway has been suggested to be critical for the emergence of embryonic HSCs from the hemogenic endothelium. Altogether, our work demonstrated that LEPR+HSCs represent a small subset of highly engrafting adult BM HSCs. These results may have potential therapeutic implications in the field of hematopoietic transplantation as LEPR is highly conserved between mice and humans.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 6 uppsatser.

Thesis (MCurr)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Haematopoietic stem cell transplantation has become an increasingly popular treatment option for persons with life-threatening blood related diseases such as leukemia, lymphoma, myeloma and certain forms of anaemia. Due to this new therapy the use of bone marrow from a healthy individual also called a living donor for transplantation is inevitable. These living donors can experience psychological and economic issues and these components needs to be addressed in the transplant protocol. The researcher described the psychosocial factors that influenced sibling donors during allogeneic bone marrow transplantation at a public sector hospital in Cape Town, whether the transplant team members explained the administrative process of the transplant in an understandable manner and language and the effect of the psychosocial factors and administrative process of the allogeneic bone marrow transplantation on the sibling donors. A quantitative research approach with a descriptive design was used in this study. The sample was selected by means of full population sampling. The final sample size of (n=64) stem cell sibling donors over 18 years of age participated in the study. A self-reporting questionnaire was used to gather data, inclusive of four open-ended questions to establish an in depth sense of what the donor experiences during the bone marrow donation process. Descriptive statistics used to describe the variables included frequency distributions in the form of histograms and frequency tables. The Pearson chi-square statistical analysis test was used to test for relationships amongst groups. The study drew on the Roy Adaptation Model (RAM) as the theoretical framework to explain the phenomena surrounding the psychosocial and administrative effect of the transplantation process on the sibling donor. Based on the findings the haematopoietic stem cell donors coped with the psychosocial impact of the donation process by making use of their coping mechanism to adapt to their situation according to the Roy Adaptation Model. This model also offers guidance to the nurses to apply this model to nursing practice. Results revealed that sibling donors developed feelings of anxiety in relation to the invasive procedures that cause them to experience physical pain. Most respondents claimed that they were not psychologically affected by the donation process. The moral obligation the sibling donor has towards his sister or brother outweighed the physical pain or discomfort experienced during the donation process. Results revealed that the responding donors claimed they were well informed regarding the donation process and understood the treatment plan of the recipient. However, results revealed that there was a lack in visual donor information such as books, pamphlets as well as internet information. Results concerning the demographics revealed that (n=29) respondents had no schooling and some respondents had some schooling which can give an indication of how to bridge the knowledge and information gap between them and the donor in terms of language. Statistical significance results regarding the emotional state and economic situation of the donors was found. Some of the respondents were responsible for their own transport and their own accommodation, some of those that are employed were responsible for leave without pay. An organ donation policy needs to be developed to prevent live organ donors from losing valuable working hours that could result in loss of salary and should provide other financial incentives. Furthermore, a lack in a post-donation follow-up medical to alleviate and detect post-donation complications was identified. Further nursing research can help nurses to understand living donation for transplantation, also how the nurses that practice in organ transplant units experience and deal with the psychosocial factors that influence them particularly. / AFRIKAANSE OPSOMMING: Hematopoïetiese stamseloorplanting het ’n toenemend gewilde-behandelingsopsie vir persone met lewensgevaarlike bloedverwante siektes soos leukemie, limfoom, miëloom en sekere soorte anemie geword. Vir hierdie tipe terapie word die beenmurg van ’n gesonde individu, ook bekend as ’n lewende skenker, vir oorplanting gebruik. Lewende skenkers kan sielkundige en ekonomiese probleme ervaar en hierdie kwessies moet in die oorplantingsprotokol hanteer word. In hierdie studie is ondersoek ingestel na die psigososiale faktore wat bloedverwante skenkers tydens allogeneïese beenmurgoorplanting by ’n openbare hospitaal in Kaapstad beïnvloed, of die oorplantingspan die administratiewe proses van die oorplanting op ’n verstaanbare manier en in verstaanbare taal verduidelik het, en wat die uitwerking wat die psigososiale faktore en administratiewe proses is op die bloedverwante skenkers tydens allogeneïese beenmurgoorplanting. ’n Kwantitatiewe benadering met ’n beskrywende navorsingsontwerp is in hierdie studie gebruik. Die steekproef is op grond van volledige populasiesteekproefneming gekies. ’n Finale steekproefgrootte van stamselskenkers (n=64) ouer as 18 jaar het aan die navorsing deelgeneem. ’n Selfverslaggewende vraelys is gebruik om data in te samel, wat vier oop vrae ingesluit het om grondige begrip te verkry van wat die skenker tydens die beenmurgskenkingsproses ervaar. Beskrywende statistiek wat gebruik is om die veranderlikes te beskryf, sluit in frekwensie-verspreidings in die vorm van histogramme en frekwensie-tabelle. Die Pearson chi-kwadraat- statistieseanalise is gebruik om die verwantskappe onder groepe te toets. Die Roy Adaptation Model (RAM) is as die teoretiese raamwerk vir die studie gebruik om die verskynsels betrokke by die psigososiale en administratiewe ervaring van die oorplantingsproses vir die bloedverwante skenker te verklaar. Op grond van die bevindinge het die hematopoïetiese stamselskenkers die psigososiale impak van die skenkingsproses hanteer deur gebruik te maak van hulle hanteringsmeganisme om by hulle situasie aan te pas, wat met die RAM ooreenstem. Hierdie model bied ook leiding aan verpleegkundiges om dit in die verplegingspraktyk toe te pas. Resultate het getoon dat bloedverwante skenkers gevoelens van angs ontwikkel het vanweë die indringende prosedures, wat fisiese pyn veroorsaak het. Die meeste deelnemers het aangedui dat hulle nie sielkundig deur die skenkingsproses geraak is nie. Die morele verpligting wat die bloedverwante skenker het teenoor sy of haar broer of suster het die fisiese pyn of ongemak gedurende die skenkingsproses oortref. Resultate het getoon dat die deelnemende skenkers aangedui het dat hulle goed ingelig was oor die skenkingsproses en die behandelingsplan van die ontvanger verstaan het. Die resultate dui egter daarop dat daar ’n gebrek was aan visuele skenkersinligting soos boeke, pamflette en internet-inligting. Resultate rakende die demografie het bewys dat van die deelnemers (n=29) ongeskoold en sommige deelnemers laag geskoold is, wat ’n aanduiding kan gee van hoe die kennis- en inligtingsgaping tussen hulle en die skenker ten opsigte van taal oorbrug kan word. Statisties beduidende resultate rakende die emosionele toestand en ekonomiese situasie van die skenkers is gevind. Sommige deelnemers was verantwoordelik vir hulle eie vervoer en verblyf. Diegene wat werk, het verlof sonder betaling geneem. ’n Orgaanskenkingsbeleid moet ontwikkel word om te verhoed dat lewende orgaanskenkers kosbare werksure verloor, wat kan lei tot ’n verlies aan salaris. Ander finansiële aansporings behoort ook gegee te word. Voorts is ’n gebrek aan opvolg mediese behandeling vir skenkers om skenkingskomplikasies vas te stel en te verlig, geïdentifiseer. Voortgesette navorsing kan verpleegkundiges help om begrip te verkry van die implikasies van lewende orgaanskenking. Verpleegkundiges wat in hierdie orgaanoorplantings- eenhede werksaam is, kan ‘n beter begrip kry van die psigososiale faktore wat hierdie skenkers spesifiek beïnvloed.

published_or_final_version / abstract / Medicine / Doctoral / Doctor of Philosophy

CBL proteins are E3 ubiquitin ligases and adaptor proteins. The mammalian homologs – CBL, CBL-B and CBL-3 show broad tissue expression; accordingly, the CBL proteins play roles in multiple cell types. We have investigated the function of the CBL-B protein in hematopoietic cells and fibroblasts. The causative agent of chronic myeloid leukemia (CML) is BCR-ABL. This oncogenic fusion down-modulates CBL-B protein levels, suggesting that CBL-B regulates either the development or progression of CML. To assess the involvement of CBL-B in CML, bone marrow transduction and transplantation (BMT) studies were performed. Recipients of BCR-ABL-infected CBL-B(-/-) cells succumbed to a CML-like myeloproliferative disease with a longer latency than the wild-type recipients. Peripheral blood white blood cell numbers were reduced, as were splenic weights. Yet despite the reduced leukemic burden, granulocyte numbers were amplified throughout the animals. As well, CBLB(-/-) bone marrow (BM) cells possessed defective BM homing capabilities. From these results we concluded that CBL-B negatively regulates granulopoiesis and that prolonged latency in our CBL-B(-/-) BMT animals was a function of perturbed homing.To develop an in vitro model to study CBL-B function we established mouse embryonic fibroblasts (MEFs) deficient in CBL-B expression. Transduction of the wild-type and CBL-B-deficient MEFs with BCR-ABL did not confer transformation; nevertheless, the role of CBL-B in fibroblasts was evaluated. The CBL-B(-/-) MEFs showed enhanced chemotactic migration toward serum in both Transwell migration and time-lapse video microscopy studies. The biochemical response to serum was extensively evaluated leading to the development of a model. We predict that CBL-B deficiency either: (a) augments GRB2-associated binding protein 2 (GAB2) phosphorylation leading to enhanced extracellular signal-regulated kinase (ERK) and protein kinase B (PKB / Akt) signaling, or (b) alleviates negative control of Vav3 resulting in stimulation of Rho effectors. In either case, our results reveal a negative regulatory role for CBL-B in fibroblast migration. The two studies detailed herein expand our knowledge of CBL-B function. They strongly suggest that CBL-B can modulate granulocyte proliferation and point toward a role for CBL-B in the motility of numerous cell types.

Advances in haploidentical bone marrow transplantation (h-BMT) have drastically broadened the treatment options for patients requiring BMT. The possibility of significantly reducing the complications resulting from graft-versus-host disease (GvHD) with the administration of post-transplant cyclophosphamide (PT-CY) has substantially improved the efficacy and applicability of T cell-replete h-BMT. However, higher frequency of disease recurrence remains a major challenge in h-BMT with PT-CY. There is a critical need to identify novel strategies to prevent GvHD while sparing the graft-versus-leukaemia (GvL) effect in h-BMT. To this end, we evaluated the impact of bendamustine (BEN), given post-transplant, on GvHD and GvL using clinically relevant murine h-BMT models. We provide results indicating that post-transplant bendamustine (PT-BEN) alleviates GvHD, significantly improving survival, while preserving engraftment and GvL effects. We further document that PT-BEN can mitigate GvHD even in the absence of Treg. Our results also indicate that PT-BEN is less myelo-suppressive than PT-CY, significantly increasing the number and proportion of CD11b(+)Gr-1(hi) cells, while decreasing lymphoid cells. In vitro we observed that BEN enhances the suppressive function of myeloid-derived suppressor cells (MDSCs) while impairing the proliferation of T-and B-cells. These results advocate for the consideration of PT-BEN as a new therapeutic platform for clinical implementation in h-BMT.

Hematologic malignancies are among the most often diagnosed forms of cancers. Treatment regimens often utilise various combination of cytostatic drugs and total body irradiation and subsequent transplantation of hematopoietic stem cells. One of the most common combinations includes ionising radiation with the antineoplastic alkylating agent cyclophosphamide. In this study we used congenic Ly5.2 and L5.1 mouse strains that express different isoforms of CD45 antigen to evaluate the effects of various time interval between cyclophosphamide and irradiation treatments on the viability of hematopoietic stem cells and their viability. This was done by competitive repopulation assay. The results revealed that level of engraftment and subsequent reconstitution of hematopoiesis can significantly vary and depend on the time interval between cyclophosphamide and total body irradiation administrations. The results indicate that patients with hematologic malignancies could possibly benefit from the treatment especially if they received transplants after being irradiated five or seven days after cyclophosphamide because at that time point their own stem cells would be least competitive. Key words: bone marrow transplantation, cyclophosphamide, chimerism, hematopoietic stem cells, ionising radiation

A Doença do Enxerto Contra Hospedeiro (GVHD) é a maior causa de morbidade e mortalidade em pacientes submetidos ao Transplante de Células-Tronco Hematopoiéticas (TCTH). As manifestações bucais podem ser debilitantes, levar a complicações sistêmicas e comprometer o prognóstico do paciente. O diagnóstico final deve ser estabelecido histologicamente. Recentemente o consenso estabelecido pelo NIH (National Institutes of Health) recomendou o uso de uma nova classificação histopatológica para o GVHD. No entanto a possível associação entre os quadros clínico e histopatológico de GVHD crônico (GVHDc), bem como a validação desta nova classificação ainda não estão claros na literatura. Desta forma, este estudo teve por objetivo validar a nova classificação, compará-la com outra já existente, correlacioná-la com o estágio clínico do GVHD e com a sobrevida dos pacientes transplantados. Para este estudo foram analisados biopsias de mucosa oral de 41 pacientes com diagnóstico clínico e histopatológico de GVHDc. Os aspectos histopatológicos foram observados pelo autor deste trabalho e pelo seu orientador, de forma cega, aplicando os critérios de Horn e do Consenso. A classificação do Consenso mostrou se válida, fácil de ser aplicada e apresentou correlação com a classificação de Horn. Não houve correlação da classificação histológica com o estágio clínico da doença e casos classificados histologicamente como mais graves estavam relacionados com menor sobrevida. / The graft-versus Host Disease (GVHD) is the major cause of morbidity and mortality in patients undergoing Hematopoietic stem cell transplantation (HSCT). The oral manifestations can be debilitating, leading to systemic complications and compromise the patient\'s prognosis. The final diagnosis must be established histologically. Recently the consensus established by the NIH (National Institutes of Health) recommended the use of a new classification for histopathological chronic GVHD (cGVHD). However, the possible association between clinical and histopathology of cGVHD, as well as validation of this new classification is not yet clear in the literature. Thus, this study aimed to validate the new classification, compare it with the existing, correlating it with the clinical stage of GVHD and the survival of transplanted patients. For this study we analyzed biopsies from oral mucosa of 41 patients with clinical and histopathological diagnosis of cGVHD. The histopathological features were observed by the author of this work and his supervisor, in a blinded fashion, using the criteria of consensus and Horn. A classification of consensus shown is valid, easy to apply and also correlated with the classification of Horn. There was no correlation with histological classification of the clinical stage of disease and cases histologically classified as more severe were associated with lower survival.

Introdução: Infecção de corrente sanguínea é uma das principais complicações dos pacientes transplantados de medula óssea. Poucos estudos avaliam os pacientes transplantados que realizam acompanhamento ambulatorial. Objetivos: Descrever o perfil dos agentes isolados de infecção de corrente sanguínea de pacientes transplantados que realizam acompanhamento ambulatorial no HCFMUSP. Avaliar a proporção e fatores de risco associados com internação e óbitos desses pacientes. Método: Análise retrospectiva dos prontuários de pacientes acompanhados no ambulatório de TMO que apresentaram hemocultura positiva colhida durante janeiro de 2004 a dezembro de 2008. Os dados foram analisados utilizando o Epi Info 3.5.1, o nível de significância adotado foi de 5%. Hospitalização e óbito em 30 dias foram os desfechos avaliados e foram calculados fatores de risco associados nas análises bivariada e multivariada. Resultados: Os principais agentes isolados foram S. maltophilia (15%), SCN (12%), Acinectobacter spp (9%). Dos episódios ocorridos, 88% eram monomicrobianos e 12% polimicrobianos, em ambas a ocorrência de gram-negativos foi predominante. A internação hospitalar ocorreu em 26% dos episódios, sendo encontrado na analise bivariada e multivariada como fator protetor a realização de transplante autólogo. O óbito em 30 dias ocorreu em 10% dos isolados e foi encontrado, na análise bivariada, como fator de risco o isolamento de gram-positivos e a presença de neutropenia grave. A análise multivariada encontrou como fator protetor para óbito em 30 dias o uso do score MASCC, não sendo evidenciados fatores de risco. Conclusões: Os gram-negativos foram os principais agentes isolados neste estudo, destacando-se o isolamento de Stenotrophomonas maltophilia. A ocorrência de hospitalização e óbito não foi elevada, o transplante autólogo foi fator protetor para hospitalização e o uso do score MASCC fator protetor pra óbito em 30 dias. Mais estudos que avaliem o tratamento ambulatorial de pacientes transplantados de medula óssea a fim de possibilitar uma melhor qualidade de vida desses pacientes são necessários / Introduction: bloodstream infection is one of the most common medical complications in bone marrow transplanted patients. A few studies in fact evaluate the transplanted patients that are under outpatient attendance. Objectives: Describe the isolated bloodstream infection agents profile on bone marrow transplanted patients that are under outpatient attendance at HCFMUSP. Evaluate the proportion and risk factors associated with hospitalization and death of such patients. Method: Retrospective analysis on patients records of the TMOs ambulatory that presents positive blood culture gathered between January 2004 and December 2008. All the data was analyzed using the software Epi Info version 3.5.1, the significance level adopted was of 5%. Hospitalization and death in 30 days were the outcomes evaluated and which the risk factors associated were calculated and compared through the analysis bivariate and multivariate. Results: The most important agents isolated were S. maltophilia (15%), SCN (12%), Acinectobacter spp (9%). From all the episodes that occurred, 88% were monomicrobial and 12% polimicrobial, in both the occurrence of gram-negative was predominant. The hospitalization happened in 26% of the episodes, being found as the protection factor to the autologous transplant on both analyses, bivariate and multivariate. On 10% of the isolated cases occurred death in 30 days, and it was found in the bivariate analysis as factor of risk the isolation of the gramnegative and the presence of serious neutropenia. The multivariate analysis found as protection factor for death in 30 days score MASCC score use and a part of that no risk factors were highlighted. Conclusion: The gram-negative were the most important isolated agents in this research, highlighting the isolation of Stenotrophomonas maltophilia. The occurrence of hospitalization and death wasnt high, being the autologous transplant a protection factor for hospitalization and the use of MASCC score the protection factor for death in 30 days. More research is necessary evaluating the outpatient treatment for bone marrow transplanted patients to make it possible a better life standard for those patients

O presente estudo caracterizou o perfil farmacológico utilizado por pacientes submetidos a transplante de medula óssea (TMO), identificou as combinações existentes entre antimicrobianos potencialmente interativos e outros medicamentos decorrentes da co-administração e analisou, a partir das combinações identificadas, as interações medicamentosas (IM) potenciais quanto aos seguintes aspectos: tipo de IM, nível de severidade, evidência cientifica e implicações clínicas potenciais. Analisaram-se 70 prescrições de medicamentos de pacientes submetidos a TMO, que se encontraram na fase de condicionamento (dia –1), e que estiveram internados, no período de janeiro a junho de 2005, no Instituto do Coração do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo. Os dados relativos ao perfil terapêutico dos medicamentos foram coletados do prontuário do paciente, e aqueles acerca das IM foram obtidos por meio de consulta ao Drug Interactions Facts e Drug Interactions Handbook. Para análise dos dados utilizou-se estatística descritiva e analiinferencial sendo aplicada a regressão logística multivariada. Os resultados apontaram que a amostra foi composta em sua maioria por pacientes do sexo masculino (52,9%), com média de idade de 37 anos, com diagnósticos de linfomas (38,6%) e submetidos a transplantes do tipo autólogo (65,7%). Quanto ao perfil terapêutico observou-se 33 medicamentos distintos pertencentes a 8 classes terapêuticas com predomínio dos quimioterápicos (34%). Observou-se que 72,7% dos medicamentos apresentaram potencial para interação medicamentosa, sendo que 79,2% eram precipitadores. Quanto à análise das características farmacológicas que predispunham as IM verificou-se que 66,6% dos medicamentos afetavam o metabolismo hepático, inibindo-o (45,8%) ou estimulando-o (20,8%). Entre os quimioterápicos antimicrobianos 66,7% apresentaram características potencialmente interativas. Metade da amostra foi exposta a combinações de antimicrobianos potencialmente interativos (fluconazol, ciprofloxacina e sulfametoxazol+trimetoprima) e outros medicamentos; sendo identificadas 13 IM distintas, todas do tipo farmacocinética. A maioria das IM (92,3%) apresentou severidade moderada, com bom nível de evidência cientifica (61,6%), que poderiam resultar em elevação dos níveis séricos do agente combinado com o antimicrobiano (77,0%), com tempo de inicio dos efeitos demorado (61,5%). Houve associação estatisticamente significante entre ocorrência de IM e sexo (p<0,001); entre IM e faixa etária (p<0,001); entre IM e número de medicamentos (p<0,001) / The present study have characterized the pharmacologic profile used by patients who undergo bone marrow transplant (BMT); identified the existing combinations between the potentially interactive anti-microbial drugs and those deriving from co-administration; and analyzed, using identified combinations, the possible drug interactions (DI) in regard to the following aspects: type of DI, severity level, scientific evidence, and potential medical implications. There were analyzed 70 prescriptions medication for patients who underwent a BMT in the phase of conditioning (day – 1), and who were in the hospital within the period of January to June 2005, in the Heart Institute of the School of Medicine Hospital of the University of São Paulo (Instituto do Coração do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo). The data related to the medication therapy profile were collected from the patient handbook and the DI data were obtained by looking up in the Drug Interactions Facts and Drug Interactions Handbook. For data analysis, the description and inferential statistics were used and the multi-diverse logistic regression was applied. The results pointed out that the sample was primarily of patients of masculine gender (52,9%), with an average age of 37 years old, with lymphoma diagnosis (38,6%) and who were undergoing auto-transplants (65,7%). In regard to therapeutic profile, there were observed 33 different drugs from 8 therapy classes mainly of chemotherapy (34%). 72,7% of the medications showed to be potentially drug interactive, whereas 79,2% of them were precipitators. As for the pharmacology characteristic analysis that predisposes DI, it was verified that 66,6% of the medications affected the hepatic metabolism by inhibiting it (45,8%) or stimulating it (20,8%). Among the anti-microbial chemotherapy drugs, 66,7% presented potentially interactive characteristics. Half of the sample were exposed to anti-microbial combinations potentially interactive (fluconazole, ciprofloxacin e sulphamethoxazole+trimethoprim) and other medicaments; where 13 different DI were identified, all of them of the pharmacokinetic type. Most of the DI (92,3%) presented moderate severity, with good level of scientific evidence (61,6%), which could result in a higher level of serum of the agent when combined with the anti-microbial drugs (77,0%), with prolonged time for starting the effects (61,5%). There was a statistically significant association between the DI occurrence and sex (p<0,001); between DI and 40-49 year-old age-group (p<0,001); between DI and more than 4 number of medicaments (p<0,001)