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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.
71

Mesenchymal stem cells for cellular cardiomyoplasty : the role of anti-inflammatory cytokines

Chen, Guangyong. January 2008 (has links)
BACKGROUND Adult bone marrow derived MSCs had been explored to treat myocardial infarction (MI) and heart failure, for which various beneficial paracrine effects had been suggested. Since MSCs in vitro express anti-inflammatory cytokines, we tested the hypothesis that changes in the pro-/anti-inflammatory cytokine ratio in the infarct microenvironment may provide such a paracrine mechanism to improve early cardiac function following acute coronary occlusion. / Methods Rats (n=88) underwent acute left coronary artery ligations and were randomized into groups M and C and then injected with culture media or MSCs, respectively. These rats underwent blinded echocardiography to evaluate left ventricular ejection fractions (LVEF). Real Time PCR was used to compare cytokine gene expression for IL-1beta, IL-6, IL-8 (pro-inflammatory) and IL-10 (anti-inflammatory) at various times. Extra-cellular matrix (ECM) deposition and inflammatory cell infiltration were also analyzed. / Results As early as 12 hours, the ratio of pro-/anti-inflammatory cytokine gene expression in group C was significantly lower than group M. Similar results were found at 24 hours, 1 and 2 weeks, respectively. LVEF improved significantly in group C (M=62% vs C=68% at 12 hours* , M=66% vs C=75% at 24 hours*, M=57% vs C=75% at 1 week *, and M=52% vs C=70% at 2 weeks*, *p<0.01). The ratio of MMP-2/TIMP1 levels was lower in the Group C at all time frames, reaching significance at 12 and 24 hours and 2 weeks. In group C, histopathological analysis revealed significantly less ECM deposition (M=1.95% vs C=0.75% at 24 hours*, M=19.30% vs C=9.36% at 1 week*, M=24.46% vs C=7.57% at 2 weeks*, *p<0.01). This was associated with significantly decreased inflammatory cell infiltration after 24 hours. / Conclusions The current data suggests that MSCs therapy decreases the pro-/anti-inflammatory cytokine ratio in the infarct microenvironment. This is associated with improved cardiac function, reduced ECM deposition, and decreased inflammatory cell infiltration. This paracrine mechanism of MSCs therapy may explain the early functional improvement after MI before cell transdifferentiation or other mechanisms takes place.
72

Curing Multiple Sclerosis : How to do it and how to prove it

Burman, Joachim January 2014 (has links)
Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for multiple sclerosis (MS) with now more than 600 documented cases in the medical literature. Long-term remission can be achieved with this therapy, but when is it justified to claim that a patient is cured from MS? In attempt to answer this question, the outcome of the Swedish patients is described, mechanisms behind the therapeutic effect are discussed and new tools for demonstration of absence of disease have been developed. In Swedish patients treated with HSCT for aggressive MS, disease free survival was 68 % at five years, and no patient progressed after three years of stable disease. Presence of gadolinium enhancing lesions prior to HSCT was associated with a favorable outcome (disease free survival 79 % vs 46 %, p=0.028). There was no mortality and no patient required intensive care. The immune system of twelve of these patients was investigated further. In most respects HSCT-treated patients were similar to healthy controls, demonstrating normalization. In the presence of a potential antigen, leukocytes from HSCT-treated patients ceased producing pro-inflammatory IL-17 and increased production of the inhibitory cytokine TGF-β1 suggesting restoration of tolerance. Cytokine levels and biomarkers of tissue damage were investigated in cerebrospinal fluid from a cohort of MS patients. The levels were related to clinical and imaging findings. A cytokine signature of patients with relapsing-remitting MS could be identified, characterized by increased levels of CCL22, CXCL10, sCD40L, CXCL1 and CCL5 as well as down-regulation of CCL2. Further, we could demonstrate that active inflammation in relapsing-remitting MS is a tissue damaging process, with increased levels of myelin basic protein and neurofilament light. Importantly, relapsing-remitting MS patients in remission displayed no tissue damage. In secondary progressive MS, moderate tissue damage was present without signs of active inflammation. From a clinical vantage point, it seems that we confidently can claim cure of relapsing-remitting MS patients after five years absence of disease activity. The new tools for evaluation of disease can strengthen this assertion and may enable earlier prediction of outcome.
73

Anti-CD20 Monoclonal Antibody (Rituximab) and Cidofovir as Successful Treatment of an EBV-Associated Lymphoma with CNS Involvement

Hänel, Mathias, Fiedler, Friedrich, Thorns, Christoph 26 February 2014 (has links) (PDF)
Background: Epstein-Barr virus(EBV)-associated posttransplant lymphoproliferative disease (PTLD) is a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT). Especially in cases with involvement of the central nervous system (CNS) treatment is difficult because the efficacy of most chemotherapeutic agents as well as EBV-specific cytotoxic donor T cells in liquor is uncertain. In the last years the anti-CD20 monoclonal antibody Rituximab was intensively investigated in the treatment of EBV-PTLD. However, only 8 patients with B-cell lymphoma and CNS involvement treated with Rituximab were reported. Case Report: A 24-year-old female patient with acute T-lymphoblastic leukemia in second complete remission had received allogeneic, unrelated, T-cell depleted HSCT. 10 months later an EBV-associated PTLD was diagnosed. Beside peripheral lymphomas and B symptoms the patient showed neurological symptoms. Examination of the cerebrospinal fluid (CSF) revealed a meningeosis lymphoblastica caused by the EBV lymphoma. Treatment with Rituximab and the antiviral drug Cidofovir led to complete remission with regression of the peripheral lymphomas and disappearance of the neurological symptoms. In addition, the PCR control on EBV DNA became negative in the plasma as well as in CSF. Conclusion: The combination of Rituximab and Cidofovir appears as an interesting alternative treatment in patients with EBV-associated PTLD and CNS involvement. / Hintergrund: Die Epstein-Barr-Virus(EBV)-assoziierte Posttransplantations-lymphoproliferative Disease (PTLD) ist eine gefürchtete Komplikation nach allogener hämatopoetischer Stammzelltransplantation (HSCT). Insbesondere bei Befall des zentralen Nervensystems (ZNS) ist die Behandlung auf Grund der unsicheren Liquorwirksamkeit der meisten Chemotherapeutika als auch von EBV-spezifischen zytotoxischen T-Spenderzellen schwierig. Der monoklonale Anti-CD20-Antikörper Rituximab wurde in den letzten Jahren bei Patienten mit EBV-PTLD intensiv untersucht. Allerdings wurde bislang lediglich von 8 Patienten mit ZNS-Befall eines B-Zell-Lymphoms berichtet, bei denen eine Therapie mit Rituximab erfolgte. Kasuistik: Eine 24-jährige Patientin hatte wegen einer akuten T-lymphoblastischen Leukämie in zweiter kompletter Remission eine allogen-unverwandte, T-Zelldepletierte HSCT erhalten. 10 Monate später wurde eine EBV-assoziierte PTLD diagnostiziert. Neben peripheren Lymphomen und B-Symptomen zeigte die Patientin neurologische Symptome. Die Liquoruntersuchung erbrachte den Befund einer Meningeosis lymphoblastica im Rahmen des EBV-Lymphoms. Die Behandlung mit Rituximab und dem Virustatikum Cidofovir führte zu einer kompletten Remission mit Rückbildung der peripheren Lymphome und Verschwinden der neurologischen Symptomatik. Außerdem wurde die PCR-Kontrolle auf EBV-DNA sowohl im Plasma als auch im Liquor negativ. Schlussfolgerung: Die Kombination von Rituximab und Cidofovir erscheint als eine interessante Therapiealternative für Patienten mit EBV-assoziierter PTLD und ZNS-Befall. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
74

Depletion of Dendritic Cells to Prevent Acute Graft Versus Host Disease.

John Wilson Unknown Date (has links)
Acute graft versus host disease (aGVHD) affects more than 40% of patients undergoing haematopoietic stem cell transplantation. aGVHD occurs after transplantation of donor haematopoietic cells into hosts incapable of rejecting the donor cells, when donor T cells attack host tissue. Despite extensive efforts, aGVHD remains problematic to prevent and difficult to control. Current therapies to prevent aGVHD induce profound immunosuppression, leaving patients at increased risk of infection and leukaemic relapse. Dendritic cells (DC) are professional antigen presenting cells of haematopoietic origin and are the primary stimulators of the immune system, uniquely being able to activate naïve T cells. A growing body of evidence suggests that DC are responsible for the stimulation of the donor T cells which cause aGVHD. I have used a model of aGVHD which utilizes conditioned severe combined immunodeficient mice transplanted with human peripheral blood mononuclear cells (PBMC). In this model human CD4+ T cells appear to be responsible for an aGVHD-like syndrome which results in death 15-30 days post transplant. I have shown, using in vitro depletion of individual populations, that other subpopulations of human PBMC did not affect the survival of the mice. I have also demonstrated that human DC are required for the induction of aGVHD in the majority of mice. This novel finding validated the use of this model to test the primary hypothesis; that antibody mediated depletion of DC would prevent aGVHD. The murine IgM monoclonal antibody (Mab), CMRF-44 Mab, is specific for an unknown molecule expressed on the surface of activated human DC. Previous work had shown that when mixed lymphocyte reaction stimulator cells were depleted of CMRF-44+ cells, there was a significant reduction in the proliferation of responder cells. Here I tested the efficacy of CMRF-44 as a therapy for the prevention of aGVHD in the model. CMRF-44 Mab did not improve survival of mice treated with human PBMC, despite recent data showing that CMRF-44 expression on DC was predictive of aGVHD in patients. In vitro depletion of CMRF-44+ cells from human PBMC prior to transplantation also did not reduce incidence of aGVHD. An alternate target for the depletion of human DC was CD83 which is also expressed on the surface of activated human DC. I generated a rabbit polyclonal antibody using a human CD83 fusion protein, which was then affinity purified in a multi-step process which yielded only antibody specific for human CD83. Treatment with this antibody greatly improved survival of transplanted mice. Further experiments showed that anti-CD83 treatment did not abrogate human leucocytes including CD8+ memory T cells suggesting that a therapy using an anti-CD83 antibody has the potential to prevent aGVHD without the immunosuppression associated with current anti-aGVHD therapies. The work described here has validated the use of a human mouse chimeric model as an in vivo assay of human DC function and shown that targeting CD83 has the potential to reduce the incidence of clinical aGVHD whilst preserving donor memory T cells.
75

Haematopoietic stem cell transplantation: Evaluation of a patient and carer psychoeducation programme

Wallbank, Kathleen L January 2009 (has links)
Master of Science / Haematopoietic stem cell transplantation (HSCT) is a complicated and high-risk procedure used to cure disease or stop the spread of disease in a range of cancers. HSCT carries a high incidence of mortality and is associated with distressing short and long-term side effects. In addition, patients remain at risk of recurrence or mortality years after transplantation. Therefore, patients undergoing HSCT have been found to experience significant emotional and psychosocial distress because of the trauma associated with treatment. The literature suggests that about 50% of HSCT patients will experience clinical levels of distress. Carers and family members play an important role in caring for these ill patients in the short and long-term. Major role changes and financial stressors are experienced in many families, adding to the burden of care. However, very little is known about the rates of psychopathology in carers of HSCT patients. Due to the arduous nature of HSCT, psycho-educational programmes have been developed by major transplant centres and hospitals in order to provide HSCT patients and their families with information on the treatment process, side effects, risks, and long-term outcomes. Research on patient education in oncology has shown that providing patients and carers with information about their illness and treatment reduces anxiety and distress. To date, there have been no empirical evaluations to support the use of education programmes for HSCT patients. While it could be assumed that information would be helpful in reducing anxiety and depression in HSCT as it is in oncology generally, the information provided to these patients is usually more confronting and therefore, may be less reassuring. Thus, it is not known whether providing patients with education about HSCT reduces patient and carer distress or whether it might actually increase adverse outcomes. The aim of the present study was to evaluate the rates and correlates of distress in carers and patients and examine the effect of a psychoeducation programme for patients undergoing HSCT and their carers on knowledge, distress, information satisfaction, social support and caregiver burden. A randomised control trial was conducted to provide empirical data in relation to the latter aim. The following hypotheses were proposed. Firstly, it was hypothesised that patients and carers who received the education programme would have higher levels of knowledge, not evidenced in a group waiting to receive the programme. Secondly, it was hypothesised that the education program would not lead to increased anxiety and depressive symptoms. Thirdly, patients who know more about their condition would be the least distressed. As predicted, this study found high levels of distress, particularly in carers. Higher patient distress was related to having more concern about one’s illness and experiencing more symptoms. Education was effective in increasing patient and carer knowledge. Importantly there were no adverse effects of knowledge and greater patient knowledge following the education program was associated with less distress, although there was no direct effect of education on distress. Future research should aim to identify what aspects of the education program are helpful to patients. Finally, support interventions such as CBT are needed to help patients and carers, in particular, cope with the high levels of distress inherent in the HSCT experience.
76

Human neural precursor cells in spinal cord repair /

Piao, Jinghua, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
77

Adult human neural stem cells : properties in vitro and as xenografts in the spinal cord /

Westerlund, Ulf, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.
78

Immune modulation by mesenchymal stem cells /

Rasmusson, Ida, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.
79

Experimental studies of human fetal liver cells : in regard to in utero hematopoietic stem cell transplantation /

Lindton, Bim, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.
80

Quality of life in patients with malignant blood disorders : a clinical and methodological study /

Wettergren, Lena, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 4 uppsatser.

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