125,949 research outputs found
Rescue of myeloid lineage-committed preprogenitor cells from cytomegalovirus-infected bone marrow stroma
No full textThe effect of murine cytomegalovirus on myelopoiesis was studied in long-term bone marrow culture to find an in vitro correlate for the lethal virus interference with bone marrow reconstitution (W. Mutter, M. J. Reddehase, F. W. Busch, H.-J. Bühring, and U. H. Koszinowski, J. Exp. Med. 167:1645-1658, 1988). The in vitro generation of granulocyte-monocyte progenitors (CFU-GM) discontinued after infection of the stromal cell layer, whereas the proliferation and differentiation of CFU-GM to granulocyte-monocyte colonies remained unaffected. A protocol was established to probe the functional integrity of earlier hematopoietic cells. Pre-CFU-GM (the progenitors of the CFU-GM) could be recovered from an infected bone marrow donor culture by transfer onto an inductive recipient stromal cell layer. Thus, at least in vitro, infection of bone marrow stroma appears to be the only cause of the defect in myelopoiesis
Transplant anxieties : discourses about bone marrow
No full textIncludes bibliographical references (leaves 89-94).This minor dissertation examines the various discourses in the Bone Marrow Transplant (BMT) network in South Africa. The organisations in the network which were observed using participant observation were the South African Bone Marrow Registry and the Sunflower Fund to complement this, the researcher interviewed staff members at these organisations as well as at a public hospital haematology unit in the Cape Town area that conducts BMT. Additionally patients, donors, and their family members were interviewed. Some media related to the BMT network was also analysed. Informed heavily by Troy Duster's work on genetic and social feedback loops, it was found that the discourses reflect a complex interweaving of biological materiality, ethnicity, culture, mortality, health resource rationing, South African nationhood, and the limits of bodily integrity. There is extensive discussion of how the BMT discourses demonstrate the necessity of engagement with several issues: the hybridity of expert and lay intercultural communication, health inequalities, human rights, and the prioritisation of first and third world medicine, the meanings of race, culture, ethnicity, and nationhood in a diverse South Africa, conceptions of donor shortage, and the imperative of saving lives through medical practise
Bone Marrow Cells in Murine Colitis: Multi-Signal Analysis Confirms Pericryptal Myofibroblast Engraftment without Epithelial Involvement
No full textThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credite
Bone marrow derived cells as endothelial precursors and the role of multi-potent progenitor cells in repairing ischaemic tissues.
No full textPhDIntroduction: Atherosclerosis and its complications are a major cause of death and
disability and it remains a major challenge to develop new therapies for patients with
irreversible end organ damage and ongoing ischaemia. The discovery of adult stem
and progenitor cells with the ability to regenerate adult tissues holds great promise.
Bone marrow is the source of both endothelial progenitor cells (EPCs) and multi-potent
adult progenitor cells (MAPCs). MAPCs are rare pluripotent bone marrow derived cells
with the theoretical potential to differentiate into tissues of all three germ cell layers,
including endothelium. These cells may have the potential to facilitate cardiac repair.
The aim of this thesis was to further characterise bone marrow derived endothelial
progenitor cells including multi potent adult progenitor cells and assess their angiogenic
potential and mechanisms of action in animal models of cardiovascular disease.
Findings: EPCs were isolated from humans and mice and their phenotype, markers
and function determined, including gene tracking experiments in mice utilising the
Cre/Lox system. It was not possible to isolate cells with the same phenotype as
MAPCs from rodent bone marrow. However, cells with pluri-potent properties, named
rat multi-potent progenitor cells (rMPCs), were isolated from rat bone marrow. These
cells had the ability to up regulate tissue specific antigens from all 3 germ cell lineages
and in addition secreted multiple cytokines related to angiogenesis and inflammation.
To investigate the in vivo properties of rMPCs a rat hind limb model of ischaemia was
established and syngeneic rMPCs were transplanted into the ischaemic hind limbs.
rMPCs engrafted selectively into the adventitia of arterioles of ischaemic muscles.
However, engrafted cells did not differentiate into an endothelial or smooth muscle
phenotype. Cytokine analysis of muscles 5 days after rMPC injection revealed raised
levels of cytokines, including chemokines MCP1 and SDR. Limb perfusion, measured
by microspheres, increased after rMPC injection. In addition a novel MRI based
assessment of ischaemic muscles revealed a significant normalisation of MRI signal
after rMPC transplantation. However, there was no improvement in limb function
assessed by treadmill running distance 4 weeks after cell injection. These findings
suggest that transplantation of rMPCs into ischaemic muscles may modulate local
inflammatory and angiogenic responses through paracrine mechanisms.
Conclusion: Despite the potential for stem and progenitor cells to be used for the
treatment of chronic cardiac ischaemia the biology of stem cells is still relatively poorly
understood, as is the mechanism of action of cells after transplantation. As set out in
the aims, the work in this thesis adds further to our understanding of both EPCs and
BM derived pluri-potent stem cells. In addition it provides insight into the hind limb
ischaemia model and the mechanism of action of cell therapy after transplantation into
ischaemic muscle
Niemann-Pick Disease Type C (a Cellular Cholesterol Lipidosis) Treated by Bone Marrow Transplantation
No full textBone marrow transplantation (BMT) has been used for a wide variety of lysosomal storage diseases with encouraging results. We report a 3-year 5- month-old girl with Niemann- Pick type C disease (NPC) who received an allogeneic BMT, The patient presented with repeated lower respiratory tract infections, hepatosplenomegaly, failure to thrive, and developmental delay. Chest computed tomography (CT) revealed diffuse interstitial lung infiltration, Bone marrow and liver biopsies revealed abundant lipid- filled foamy macrophages, Skin fibroblast sphingomyelinase assay revealed partial deficiency, The ability of her skin fibroblasts to esterify cholesterol was very low, and the cells stained brightly for free cholesterol, She received BMT from a healthy HLA-identical male sibling donor at the age of 2 year 6 months. Full engraftment was evidenced by repeated bone marrow sex chromosome studies. Regression of the hepatosplenomegaly, markedly reduced foamy macrophage infiltration in bone marrow, and decreased interstitial lung infiltration was noted 6 months after BMT, Her neurological status, however, deteriorated. Follow-up magnetic resonance image (MRI) revealed progressive, diffuse brain atrophy . We conclude that resolution occurred in the liver, spleen, bone marrow and lung following successful engraftment, Such a response is remarkable since the underlying problem involves a membrane receptor for cholesterol, This positive response might be due to replacement of the monocyte- phagocytic system or it may imply the existence of cross- correction in the NPC membrane receptor defect by BMT approach. Since BMT did not halt the neurological deterioraton, it is unlikely to be an adequate treatment for NPC
Protein and gene expression analyses in bone marrow stem cells mediated restoration of myocardium after ischemic insult
No full textPhDMyocardial Infarction (MI) is caused by occlusion of the coronary artery following
atheromatous plaque rupture, the subsequent ischemia in the myocardium leads to
myocyte necrosis unless treated quickly. Bone marrow derived stem cell treatment is
a promising therapy for improving the outcome of patients with MI. The aim of this
thesis was to study myocardial protein and gene expression changes in a rat
ischemia/reperfusion (I/R) model in order to look for potential repair mechanisms of
the myocardium triggered by endogenous bone marrow mononuclear cells
(BMMNCs).
Rat myocardial samples were obtained from three experimental groups: one group
had a sham operation, the other two groups had undergone myocardial I/R injury
induced by left anterior descending (LAD) coronary artery ligation followed by
treatment with either a BMMNC preparation or PBS. Comparative proteomic
analyses were carried out using 2D electrophoresis; differentially expressed proteins
were identified using LC-MS/MS. Western blotting was used to confirm the most
significant findings including expression of 14-3-3 epsilon protein. Global
comparative gene expression profiling was performed using Illumina RatRef12
BeadChips and QPCR was used to validate the top results. Bioinformatic tools were
used to assess the biology of the differentially expressed genes and proteins.
Thirty-seven proteins were found to be differentially expressed in I/R injury
compared to sham. These were primarily sarcomeric, energy production or stress
response proteins and most were down-regulated. Expression levels were ‘corrected’
by BMMNC treatment for many of these proteins. Over 1500 genes were affected by
I/R injury, 20 were affected by BMMNC treatment, and many of these were related to
inflammation and apoptosis signalling and responses. The 14-3-3 epsilon protein was
chosen for follow-up work as it presented as a good candidate for mechanistic
involvement. This protein has many roles including interactions with the proapoptotic
BCL2-associated agonist of cell death (Bad) protein. Western blotting was
used to look at Bad expression and found it to be significantly increased in the
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treatment group, although I could not reliably measure the expression of
phosphorylated (serine 136) form of Bad. A preliminary pull-down assay was
performed to look for binding partners of 14-3-3 epsilon. Two ATP synthase
subunits, one of which is known to bind 14-3-3 epsilon, a protein involved in fatty
acid β-oxidation and a protein of unknown function were found to bind. Further
work will be required to follow up these findings and ascertain the exact role of 14-3-
3 epsilon in cardioprotection. In summary, my data supports the power of profiling
methods to derive new candidates for a role in repair mechanisms in this therapeutic
model
Differential Diagnoses of Systemic Mastocytosis in Routinely Processed Bone Marrow Biopsy Specimens: A Review
No full textDiagnosis of systemic mastocytosis (SM) is mainly based on the morphological demonstration of compact mast cell infiltrates in various tissue sites. In almost all patients such infiltrates are detected in the bone marrow. Reliable immunohistochemical markers for the diagnosis and grading of SM have been established, but various differential diagnoses including myeloproliferative neoplasms, basophilic and eosinophilic leukemias may be very difficult to delineate. Even more challenging is the recognition of hematological neoplasms with signs of mast cell differentiation but not fulfilling diagnostic criteria for SM, especially the rare myelomastocytic leukemia. It is also important to separate the reactive state of mast cell hyperplasia from indolent variants of SM, especially those with a very low degree of bone marrow infiltration and absence of compact mast cell infiltrates. When the lymphocytic component of the SM infiltrate is very prominent, SM may be confused with an indolent lymphoma, especially lymphoplasmacytic lymphoma which almost always shows a marked reactive increase in mast cells. In aggressive and leukemic variants of SM, mast cells may be very atypical and devoid of metachromatic granules. This hypogranulation can be regarded as cellular atypia and may lead to the misdiagnosis aspect of monocytic leukemia or histiocytic neoplasm. Regarding immunohistochemical anomalies, mast cells in aggressive and leukemic SM have been found to express CD30 (Ki1-antigen). Thus, anaplastic large cell lymphoma or Hodgkin's disease may first be considered rather than SM. There is increasing evidence that most patients with long-standing adult-type urticaria pigmentosalike skin lesions have in fact indolent SM. Therefore, such skin lesions are an important clue to the correct diagnosis in these patients. However, in aggressive or leukemic SM skin lesions are usually absent and then the correct diagnosis relies on an appropriate investigation of bone marrow biopsy specimens using both SM-related immunohistochemical markers (tryptase, KIT, CD25, CD30) but also markers excluding potential differential diagnoses. Investigation for presence of the activating KIT point mutation D816V is very helpful to establish a correct diagnosis of SM in all the difficult cases exhibiting a low degree of bone marrow infiltration or puzzling morphological findings. Copyright (C) 2010 S. Karger AG, Base
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Clinical utilization of Chimeric Antigen Receptors T-cells (CAR-T) in B-cell acute lymphoblastic leukemia (ALL) - an expert opinion from the European Society for Blood and Marrow Transplantation (EBMT) and the American Society for Blood and Marrow Transplantation (ASBMT).
No full textOn August 30, 2017, the U.S. Food and Drug Administration (US-FDA) approved tisagenlecleucel (KYMRIAH, Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor-T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring and disease assessments. To address these issues, experts representing the American Society for Blood and Marrow Transplant (ASBMT), the European Group for Blood and Marrow Transplantation (EBMT), the International Society of Cell and Gene Therapy (ISCT), and the Foundation for the Accreditation of Cellular Therapy (FACT), formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved
In vitro and in vivo characterization of murine bone marrow stromal stem cells: self renewal, differentiation, tumorigenic potential
No full textThe use of adult stem cells for applications such as tissue engineering and gene therapy is one of the major challenge approaches of regenerative medicine. In the field of adult stem cells, bone marrow stromal cells (BMSCs) are very promising candidates.
The ability to move forward the use of these cells in therapy depends on the setting up of mammalian models, necessary to evaluate pre-clinical efficacy and standardize procedures. Precisely, murine BMSCs (mBMSCs) characterization is a major breakthrough that can benefit from numerous established genetic models of human diseases now available in this organism. In particular, C57Bl/6 strain is frequently used to prepare transgenic mice because it produces a large number of high-quality embryos and super-ovulate in response to hormone injections.
However, the BMSC is a cell type better studied and characterized in humans than in mouse and, although in the last few years numerous protocols have been developed to isolate these cells, some problems still remain.
In the present study, I define, for the first time, conditions for optimizing the yields of cultures enriched for specific progenitors of bone marrow. I isolated four different sub-populations of mBMSCs using four distinct culture conditions, supernatants from culture of bone fragments, marrow stroma cell line MS-5, embryonic fibroblast cell line NIH3T3 and a cocktail of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). These cells show very interesting features in immunophenotype, self-renewal ability and differentiation potency. In particular, using NIH3T3 conditioned medium, we obtained cells that show impairment in osteogenic and chondrogenic differentiation, whereas retaining a very high adipogenic potential during passages. These results indicate that the choice of the medium used for isolation and expansion of mBMSCs is extremely relevant in order to enrich the culture of desired specific progenitors.
A common characteristic among these sub-populations of mBMSCs was the expression of a well known marker of undifferentiated embryonic stem cells, namely Nanog. Recent studies have demonstrated the expression of Nanog in BMSCs and its effect on proliferation and osteogenic and chondrogenic abilities, however its role in these cells is still unknown.
During a six- month period as visitor in the laboratory coordinated by Dr Nicole Horwood, at Imperial College (London, UK), I have generated vectors expressing Nanog sense and antisense in order to analyze the effect of over-expression and down-regulation of Nanog on migration, senescence, apoptosis and tumorigenesis in BMSCs. Preliminary data suggest that over-expression of Nanog does not seem to efficiently reduce the number of senescent cells; however, Nanog over-expressing cells showed a decrease in the expression of p53, a well known tumor-suppressor gene and acquired the ability to grow in soft agar, an in vitro hallmark of tumorigenic cells. On the other hand, down-regulation of Nanog in BMSCs enhances migration ability, and induces an increase in the expression of CCL5 (Rantes) and CXCL10 (IP10, interferon γ inducible protein-10), which have been reported to enhance motility, invasion and metastasis of breast cancer cells and to have a potent thymus-dependent antitumoral effect.
This work suggest that defined levels of Nanog could affect BMSCs properties and indicate a further need of a better understanding of the biology of these cells which are already being used in several clinical trials
A reduced intensity conditioning regimen of fludarabine, cyclophosphamide, antithymocyte globulin, plus 2 Gy TBI facilitates successful hematopoietic cell engraftment in an adult with dyskeratosis congenita
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