Dissertations / Theses on the topic 'YI 6530'
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Endres, Michaela. "Entwicklung eines bioartifiziellen Trachealersatzes." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/15359.
Full textThe replacement of extensive tracheal defects resulting from intensive care medicine, trauma, or large resections is still challenged by the re-epithelialization of an autologous or alloplastic trachea replacement. Therefore, this thesis was performed to investigate the potential of culture expanded human respiratory epithelial cells (hREC) to regenerate a functional epithelium for trachea tissue engineering.hREC from nasal turbinates were freshly isolated, expanded and subsequently cultured in high-density multilayers to allow epithelial differentiation. Composition of epithelial cells in native respiratory epithelial tissue and culture expanded hREC were analyzed by histological staining and by immunohistochemical staining with the specific antibodies. Differentiation of culture expanded hREC was further characterized by gene expression analysis of a cytokeratin pattern using semi-quantitative real-time RT-PCR technique. Furthermore, basal cells known as progenitors of the respiratory epithelium were seperated by Fluorescense Activated Cell Sorting with the basal cell specific antibodies CD49f and CD104. Co-cultures of hREC and human chondrocytes (hCHO) or human cartilage respectively were compared to Air-Liquid-Interface cultures containing hREC and hCHO.Histological and immunohistochemical staining and Scanning Electron Microscopy pictures of hREC in differentiation cultures demonstrated basal cells covering the collagenous matrix. These cells formed a cellular multilayer, which is composed of a basal layer of undifferentiated basal cells and an upper layer of cells differentiating along the squamous metaplasia and ciliated cell lineage. Lineage development of cultured hREC was further documented by the induction of specific cytokeratins. Our results suggest that culture expanded hREC have the potential to colonize collagen coated biomaterials as well as autologous cartilage grafts and to regenerate epithelial cell types for trachea tissue engineering.
Tullius, Stefan. "Die chronische Transplantatschädigung." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/13724.
Full textHoffmeister, Bodo. "Durchflusszytometrische Epitop-Kartierung von HCMV-spezifischen T-Zellen herz- und lungentransplantierte Patienten." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2004. http://dx.doi.org/10.18452/15083.
Full textBACKGROUND: Human cytomegalovirus (HCMV) reactivation is still a leading cause of morbidity and mortality among immunosuppressed patients. Uncontrolled viral spread is prevented by an efficient T-cell response. However, little is known about the nature of this T-cell response. In this study we identified epitopes in two immunodominant HCMV-proteins, IE-1 (UL123) and pp65 (UL83), measured the frequencies of T-cells specific for these, and studied the clonotypic composition of selected T-cell responses in a group of HCMV-seropositive heart (n = 17) and lung (n = 3) transplant patients. METHODS: For both proteins overlapping pentadecapeptides covering the entire respective amino acid sequences were arranged in pools of 25 peptides each in such a way that every peptide was contained in exactly 3 pools. PBMC were stimulated with the resulting 15 pools for IE-1 or 16 pools or pp65, respectively, as well as with pools containing all peptides of the corresponding protein. Individual peptides leading to a positive T-cell response were identified by flow cytometric detection of intracellular interferon-gamma, each single peptide corresponding to a unique combination of 3 peptide pools. Selected T-cell populations specific for the previously identified single peptides were purified by performing an IFN-gamma secretion assay prior to magnetic cell separation and subsequent fluorescence-activated cell sorting. The clonality of these highly purified peptide-specific T-cell populations was then investigated by a T-cell receptor-gamma rearrangement-PCR and subsequent fragment analysis of fluorescence-labelled PCR amplificates. RESULTS: We observed broad heterogeneity among the patients in terms of the immunodominant protein, number of epitopes, predominance of CD4 or CD8 T-cell responses, and epitope-specific T-cell frequencies. 10 previously unknown epitopes were identified, and the HLA-restriction of most of the identified epitopes could be determined. The investigated T-cell responses showed a high degree of clonal focussing. These data were correlated to the patients episodes of HCMV reactivation, but a correlation between differences in the T-cell responses and a different clinical outcome in terms of HCMV-reactivation could not be established. CONCLUSIONS: In summary, this novel approach allows the rapid identification of epitopes contained in a given protein, direct determination of T-cell frequencies, and investigation of the T-cell clonality in the CD4 and CD8 T-cell subsets from as little as 2 times 20 ml of blood. Long-term follow-up of patients at risk for HCMV reactivation and disease may thus allow a more detailed insight into the complexity of the T-cell response to HCMV and may thus lead to improved diagnosis, prophylaxis and therapy.
Gebauer, Bernhard. "Hyaluronsäure als Verlaufsparameter im Rahmen der Lebertransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 1998. http://dx.doi.org/10.18452/14386.
Full textSevere infections and rejections are the most frequent complications following liver transplantation. Hyaluronic acid (HA) as a component of the extracellular matrix is cleared from the circulation only by sinusoidal liver cells (SEC). So the concentration of plasma HA depends upon the flow of HA in the circulation (e.g. increased HA-production in fibroblasts after cytokine stimulation and release) and the metabolic function of the SEC. SECs are suspected to be the first targets in allograft liver rejection. 81 patients with 85 liver transplantations were monitored for routine parameters and plasma HA on a daily basis. Of 81 patients, 28 patients (34,6%) developed acute rejection. 14 patients were successfully treated with methylprednisolone (steroid-sensitive acute rejection, AR), while 14 patients required additional treatment with FK506 or OKT3 (steroid-resistant acute rejection, SR). 4 patients developed an early chronic rejection (CR) within the first postoperative year. 10 patients developed a severe postoperative infection, 11 patients had a mild or asymptomatic cholangitis, while 37 patients had an uneventful postoperative course. Mean HA levels were elevated in patients with AR compared with patients with an uneventful course. A further increase in HA was noticed in patients with SR (p
Kubo, Andreas. "Osteoporose nach Lebertransplantation:Gewicht von Lebergrunderkrankung, Anabolen Sexualhormonen, Immunsuppression sowie Therapie mit Calcitriol als Monotherapeutikum und in Kombination mit Kalzium und Natriumfluorid." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/14454.
Full textSecondary osteoporosis is a frequent complication of endstage liver disease which often detoriates after orthotopic liver transplantation (OLT). Management and therapy of osteopenic bone disease are still a major problem in liver transplant recipients. First purpose of this study was to estimate the magnitude of various specific liver diseases, sexual hormones and immunosuppression on bone loss in patients undergoing OLT. The second aim was to evaluate the effect of calcitriol (1,25(OH)2D3) in comparatively low dosages of 0,25 µg and 0,5 µg as a single therapy or in combination with 1000 mg calcium (Ca) in light and moderate osteoporosis. Patients with severe osteoporosis received a triple combination with 0,5 µg calcitriol, 1000 mg Ca and 25 mg sodium fluoride. Out of 860 patients undergoing OLT from 1988 to 1996, 509 (256 males, 213 females) were assigned to 5 treatment groups as well as to a control group. Bone mineral status and the effect of therapy were estimated by bone mineral density (BMD) measurements with dual energy X-ray absorptiometry of lumbar spine (LS) and femoral neck (FN) before and every six month after OLT. Primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune cirrhosis were associated with a low pre-existing bone mineralisation and most severe decrease of bone mass during the early post-transplantation period. Considering hormonal measuring performed during the study period 17,5% of all measured testosterone levels in men and 78,3% of all measured oestrogen levels in postmenopausal women were in hypogonadic range. Testosterone and oestrogen levels were not significant different among with calcitriol treated and non-treated patients. Baseline immunosuppression consisted of cyclosprin A or tacrolimus initially combined with corticosteroids. Patients treated with tacrolimus had significant less bone mass reduction in the lumbar spine than patients treated with cyclosporine (p=0,0249). This observation was certainly caused by less application of prednisolone. With calcitriol treated patients received considerably more prednisolone and over a longer period of time than non-treated controls. Bone mineralisation essentially increased under calcitriol therapy in all treatment groups. Whereas the low dose of 0,25 µg needed a complementation of Ca especially to achieve better results in the FN, the dosage of 0,5 µg led to BMD improvement of 10,17% in LS and 5,9% in FN without Ca and to an improvement of 10,0 % in LS and 5,2% in FN with Ca supplementation in an average period of 1,5 years. The triple combination with 0,5 µg calcitriol, 1000 mg Ca and 25 mg sodium fluoride which was used in cases of severe osteoporosis showed the best results with a BMD augmentation rate of 10,67% in LS and 12,79% in FN after a period of 1,15 years. In the untreated controls we only found spontaneous BMD improvement of 2,25% in LS and a further bone loss of 0,86% in FN. A small fracture rate of 1,77% was observed. Calcitriol therapy effectively prevents posttransplant bone loss and augments bone mineralisation in osteoporotic patients. Moreover it minimizes the incidence of atraumatic fractures. Additional sodium fluoride increases the bone density in LS and has a special effect on FN. Side effects are negligible.
Himmelreich, Gabriele. "Pathophysiologische und therapeutische Beeinflussung von Hämostasestörungen bei der orthotopen Lebertransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2002. http://dx.doi.org/10.18452/13789.
Full textThe orthotopic liver transplantation (OLT) has become an established method in the treatment of end stage liver disease and has ameliorated its prognosis substantially. During liver transplantation severe haemorrhage intraoperatively clearly influences the patient´s short and long-term outcome. The pathophysiology of hemostasis during OLT was studied and new strategies of therapy developed. It could be demonstrated that the high blood loss during the anhepatic phase is caused by increased fibrinolytic activity involving the extrinsic fibrinolytic system with tissue-type plasminogen activator (t-PA) as well as the intrinsic fibrinolytic system with urokinase-type PA (u-PA) and the FXII-dependent PA. For the easier determination of the later a chromogenic substrate method was developed. High venous pressure, contact activation initiated by the contact of the patient's blood with the veno-venous bypass and the lack of hepatic clearance are the main initiating factors of fibrinolysis during the anhepatic phase. In the reperfusion phase signs of increased prothrombin activation could be measured so that a DIC-like constellation could be made responsible for the blood loss after reperfusion of the graft liver. There was no correlation to the preceding anhepatic fibrinolysis. The graft liver plays an important role in inducing hemostatic disturbances during reperfusion. Activation products of leukocytes like extracellular proteinases and cytokines are released out of the graft liver and seem to induce hemostatic imbalances systemically. In parallel there is a decrease of platelet count and platelet aggregability. This seems to be induced in part by the University of Wisconsin solution in which the graft liver is kept until transplantation. Aprotinin, a protease inhibitor, given during OLT seems to reduce signs of hyperfibrinolysis, maximal t-PA values, transfusion requirements and endothelial damage of the graft´s liver vascular bed. In an open and randomised clinical trial the advantage of a continuous aprotinin infusion in comparison to a three times bolus application was demonstrated. In another open and randomised study prostaglandin (PG)E1 was given in order to influence endothelial activation processes in the graft liver. The administration of PGE1 was leading to a significant lower decrease of platelet count and platelet aggregability.
Meißner, Wassilios Georgios. "Vergleich verschiedener Konservierungslösungen in der Langzeitperfusion der Leber anhand klinisch-chemischer Parameter." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 1999. http://dx.doi.org/10.18452/14457.
Full textCOMPARISON OF DIFFERENT PRESERVATION SOLUTIONS FOR LONG-TERM CONTINUOUS PERFUSION OF THE LIVER The introduction of the University of Wisconsin (UW) solution for liver preservation in 1988 allowed for the first time the extension of the safe cold storage time up to 24 hours. Nevertheless, severe organ dysfunction of the liver may still occur postoperatively, depending on the quality and the duration of organ preservation. Therefore, improved organ preservation should make possible a higher rate of immediate organ function after transplantation and the extension of the safe cold storage time avoiding any wastage of organs due to liver dysfunction. Our study aimed to investigate whether continuous perfusion of pig livers in comparison to simple cold storage with the UW solution results in improved preservation. Furthermore, we examined if our extracorporal perfusion system, modified by P. Neuhaus, would be suitable to test new preservation solutions before clinical use allowing the establishment of a new in-vitro model. Thus, livers were perfused continuously using the Free University (FU) solution and the Histidine Tryptophan Ketoglutarate (HTK) solution respectively and preservation was compared to the UW solution. The preservation injury was measured in-vitro during a subsequent warm perfusion of the organ with pig blood. Differences between continuous perfusion and simple cold storage were significant. Lower concentrations of the transaminases in the UW group were associated with a higher bile secretion, a lower arterial pressure and a lower increase of the liver weight. Results obtained for the FU group suggest a comparable quality of preservation compared to livers continuously perfused with UW solution, whereas the extent of the preservation injury was significantly higher in the HTK group. In conclusion, in our experimental design continuous perfusion with UW solution seems to be a better method for organ preservation suggesting that the clinical use of this technique may be beneficial. Large experience with continuous perfusion for human renal procurement has proven its technical feasibility.
Wiegemann, Thomas. "Analyse der Morphologie des Myokards, der Koronararterien und der großen Gefäße von Spenderherzen für Klappenhomografts." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/14533.
Full textThis work contains an analysis of 317 records with a detailed description of the morphology of myocardium, coronary arteries, aortas and pulmonary arteries of hearts dissected for the purpose of harvesting the aortic and pulmonary valves as allografts in the Heart Valve Bank of the German Heart Institute, Berlin, from 1996 through 1998. 178 hearts stemmed from patients who recieved heart transplants. Naturally these organs revealed severe pathologic findings. Cadaveric organs (non beating hearts) amounted to six. 133 hearts were taken from brain dead human beings. Many of these 133 donor organs were originally considered to be potentially usable for transplantation, but were discarded for various reasons. The objective of this retrospective study was to ascertain the morphologic state of the hearts with special focus on the 133 donor hearts.
Spree, Eckhard. "Lebertransplantation bei äthyltoxischer Lebererkrankung." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/14544.
Full textFrom 1988 to 1998 at the Virchow-Clinic, Medical Faculty Charité of the Humboldt University of Berlin 1000 orthotopic liver transplantations were performed in 911 patients Out of these patients there were 167 patients with the LTX-indication ALD. In the chapter "Relapse to alcohol abuse and postoperative compliance" 117 patients with the LTX-indication or additive diagnosis ALD were regarded. The incidence of performed retransplantations was not significantly different from patients with other indications. Out of 167 ALD-Patients n=15 (9,0%) died. The 1-year-survival of the ALD-patients was 96,8%, the 5-year-survival 85,9% and the 9-year-survival 83,3%. Patient and graft survival compared well with other indications. There were no significant differences in the incidence of acute steroid-sensible nor steroid-resistant rejections between Patients with ALD and other indications. In all patients the incidence of acute rejetions in the Cyclosporine A treated patients did not differ significantly from the FK506 treated patients. Acute steroid-resistant rejection was observed significantly less frequently in the FK506 treatment group than in the Cyclosporine A treatment group. Chronic rejections occurred in similar frequency as observed in patients transplanted for other indications. Neither there were significant differences in the incidence of chronic rejections in the both immunosuppressant groups of ALD-patients. Of 117 Patients with the LTX-indication or additive diagnosis ALD alcohol relapse for at least one time occurred in 27 patients (23%). Relapse was serious in 19 cases (16,2%). Postoperative compliance was good in 84 patients, moderate in 28 patients and poor in 5 patients. Patients who developed an alcohol relapse or who had a moderate or poor compliance showed a high-significant shorter duration of abstinence prior to transplantation than patients who developed no relapse or who had a good compliance. There was a remarkable high-significant increase of alcohol relapse or moderate or poor compliance in patients with an abstinence duration shorter than 1/2 year. Patients with a serious alcohol abuse or an additive drug abuse in history showed a significantly increased incidence of postoperative alcohol relapse. Women showed a significantly higher incidence of relapse or poor or moderate postoperative compliance than male recipients. Patients who developed a postoperative relapse were significantly younger than patients without relapse. Age failed to correlate with postoperative compliance. Education level and professional position showed no significant correlation with relapse and compliance. Recurrence of alcohol disease and moderate compliance were observed significantly increased in Patients with a poor psychological personal stability compared with patients with a good personal stability. Social environment failed to correlate with relapse or postoperative compliance. Patients whose postoperative compliance was preoperative assessed as moderate or questionable developed a significantly increased rate of serious alcohol relapse compared with patients whose compliance was assessed as good. Patients whose risk of alcohol relapse was assessed as moderate or questionable showed a significantly higher incidence of postoperative relapse. Preoperatve assessment of compliance or relapse failed to correlate with postoperative compliance.
Lippek, Frank. "Hemmung der Selektin-vermittelten Granulozytenadhäsion durch Fucoidin in der frühen Reperfusionsphase nach Ischämie im Modell der ex-vivo hämoperfundierten Schweineniere." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2001. http://dx.doi.org/10.18452/14629.
Full textRenal postischemic reperfusion injury constitutes a significant problem after kidney transplantation. The polysaccharide fucoidin (360 mg/l) improves postischemic function in Ratliver, presumably by blocking selectin-mediated leukocyte adhesion. Twelve pairs of ischemic pig kidneys were reperfused in an ex vivo model with autologous blood with or without fucoidin (100 mg/L). Fucoidin resulted in a significant decrease of renal blood flow (55 ( 28 vs. 143 ( 97 mL*min-1*100g-1, p < 0.001) and increased vascular resistance (2.9 ( 2.8 vs. 1.1 ( 1.5 mmHg*mL-1*min-1*100g-1, p < 0.001). Compared to untreated control kidneys significantly more interstitial and intravascular leucocytes were found in fucoidin treated kidneys. Intraglomerular fibrinogen and thrombocytic aggregates were also increased significantly. Granulocytic emboli were present in afferent glomerular arteries of 10/12 fucoidin-treated kidneys and in 2/12 controls (p < 0.001). L-selectin-dependent granulocytic aggregation under shear stress in vitro was prevented by fucoidin in a dose-dependent fashion. However similar concentrations used in reperfused kidneys caused large granulocytic aggregates. The observed formation of embolizing granulocytic aggregates indicates limited effectiveness of fucoidin as an inhibitor of selectin-mediated leukocyte adhesion.
Klose, Holger. "Langzeitergebnisse nach homologem Aortenklappen- und Aortenwurzelersatz bei florider Aortenklappenendokarditis." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/15353.
Full textObjective: Cryopreserved aortic valve homografts have become an accepted valve substitute in acute aortic valve endocarditis, but long-term studies of valve function are largely unavailable. This survey represents our observations over a period of 17 years. Material and methods: Between February 9, 1987 and October 30, 2003, 203 patients with infective aortic valve endocarditis underwent allograft replacement of the aortic valve (free-hand subcoronary technique, n=107 and root replacement, n=96). The patients’ age ranged between 2 and 82 years with a mean age of 51.3 years. The survey included 42 females and 161 males. 161 had infected aortic root with ring abscesses. Results: The hospital mortality of patients with native and prosthetic endocarditis complicated by periannular abscess was 14.9% (17.5%) and 29.2 % (29.6%) respectively making an overall hospital mortality of 21.2% (23.6%). 17 years patient survival in patients with and without periannular abscess was 70.4+3.6% and 78.6+6.3% (p=0,24) respectively. There were 12 events of recurrent endocarditis in patients with periannular abscess, giving an actuarial freedom of 91.6+2.4% at 17 years. Reoperation was performed in 37 patients for a variety of reasons, and overall freedom from reoperation was 75.0+3.7% at 17 years. Freedom from explantation for structural valve deterioration was 96.0+2.0% at 17 years for patients with periannular abcess. No thrombembolic event was evident. Univariable analysis identified recurrent endocarditis (p=0.0001) and undersized allograft (p=0.001) as risk factors for reoperation for both native and prosthetic aortic valve endocarditis. No risk factors for hospital mortality were found. Conclusion: Aortic allograft offers an excellent long-term clinical result in patients with infective aortic valve endocarditis with associated periannular abscess. Operative mortality is acceptable based on the severity of aortic pathology, with low evidence of recurrent endocarditis and no thrombembolic events. Undersized allograft and recurrent infection are risk factors for reoperation.
Hoff, Uwe. "Bedeutung der Alloantigen-unabhängigen Faktoren in der Frühphase nach tierexperimenteller Nierentransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/15249.
Full textOrgan damage due to long cold preservation is associated with delayed graft function and has important effects on graft survival. Aim of this study was to determine the impact of ischemia-reperfusion (IR) injury compared to antigen-specific mechanisms and the effect of prolonged cold ischemia on intragraft injury and antigenicity during the early phase post transplantation. Rat renal grafts were four-hours cold-preserved, transplanted to syngeneic (Lew/Lew) or allogeneic recipients (F344/Lew) and harvested at 8 different time points after transplantation for further investigation of functional, immunhistochemical and histologic changes. In five additional syngen groups organs were cold preserved from 2 hours to 48 hours and harvested after 24 hours post transplantation. No significant differences in renal function, morphologic changes, cellular infiltration and expression of adhesion molecules occurred between syngeneic and allogeneic groups within the first 7 days. Initial functional impairment was accompanied by the influx of neutrophils and monocytes/macrophages together with morphologic changes reflecting acute tubular necrosis (ATN). Increasing infiltration of monocytes/macrophages paralleled functional and morphologic regeneration. Extravasation of neutrophils was mediated mainly by interaction of ICAM-1/LFA-1 and infiltration of monocytes/macrophages by VCAM-1/VLA-4. Treatment with the standard dose of Cyclosporin A (CsA) lead to a significant decrease of ED1-positive macrophage infiltration 10 days post NTx but the portion of ED2-positive macrophage subtype was not affected. Prolonged cold organ preservation lead to more severe vascular damage indicated by decreased color intensity and continuity of PECAM-1 staining on endothelial cells. Higher staining intensity for Tissue Factor (TF) on endothelium and infiltrating leukocytes implicated enhanced intragraft procoagulant capacity and alternative adhesion mechanisms. These results show that within the first 10 days post transplantation phases of tissue injury and repair after ischemia-reperfusion are largely independent of the immunologic background and monocytes/macrophages play an important role as mediators during these processes.
Hiemann, Nicola. "Histomorphometrische Untersuchungen myokardialer Blutgefäßveränderungen nach Herztransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 1998. http://dx.doi.org/10.18452/14461.
Full textIn this study, immunohistochemical and histomorphometric investigations were performed in order to investigate the expression of CD 31 (immunohistochemical marker for endothelial cells) and -Aktin (immunohistochemical marker for smooth muscle cells) on cells of intramyocardial blood vessels in heart transplant (HTx) patients. The evaluation of myocardial structures also implicated the investigation of the corresponding histological H & E stainings. The aim of this study was to ascertain whether HTx patients with angiographic evidence of graft vessel disease (GVD) showed different qualitative and quantitative expression of the above mentioned immunomarkers than HTx patients with no angiopraphic or postmortem signs of this phenomenon. The investigation time included the first 14 months after HTx. The use of these immunomarkers made possible the selective representation of the terminal vascular system to answer the question, as to whether there existed an intramyocardial morphological correlate to GVD of epicardial coronary arteries and whether histomorphometric evaluation of small vessels permits early diagnosis of GVD after HTx. In addition, demographic data, as well the number and grade of rejection episodes of the studied patients, were reviewed in order to ascertain whether there might be an association of these characteristics with GVD. The material studied consisted of paraffin-embedded right ventricular rejection control samples from routine postoperative diagnostic management, which were used to reveal acute rejection episodes. After morphological evaluation of histological slices with regard to the appearence and severity of acute rejection, immunohistochemical staining was performed and finally a quantitative investigation was done. According to the results of this study, quantitative histomorphometric investigations of intramyocardial blood vessels in right ventricular rejection control samples permit the early diagnosis of GVD after HTx and completes the present diagnostic tools. But further prospective clinical studies are necessary to confirm these results.
Unterhauser, Frank Norman. "Revaskularisierung und Nachweis von Myofibroblasten im freien Sehnentransplantat nach vorderem Kreuzbandersatz." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2004. http://dx.doi.org/10.18452/15016.
Full textAfter replacement of the anterior cruciate ligament with a free tendon autograft, the substitute initially is avascular and without a synovial surface. To ensure long-term survival, the graft must become revascularised. Despite numerous studies on the topic, there still is controversial discussion regarding revascularisation. The first aim of the current study was to investigate the endoligamentous microcapillary revascularisation of the free tendon graft after anterior cruciate ligament replacement with time. Furthermore degeneration and reformation of the extracellular matrix during remodeling of the anterior cruciate ligament graft was to elucidate. Contractile fibroblastic cells expressing the alpha-smooth muscle actin isoform, so called myofibroblasts, have been identified to play a possible role during the healing of the medial collateral ligament by means of restoring the tissue s in situ strain via extracellular matrix contraction. Recently, these cells have also been identified to be a normal part of the human anterior cruciate ligament. It has been hypothesised that myofibroblasts play a role in wrinkling of the extracellular matrix. Therefore the second aim of the current study was to identify myofibroblasts in the intact ovine anterior cruciate ligament and their reoccurrence in a free autologous tendon graft during remodeling after anterior cruciate ligament reconstruction. Thirty-six mature sheep had an anterior cruciate ligament reconstruction with an ipsilateral flexor tendon split graft. Besides conventional staining to analyse total cell density and collagen crimp, midsubstance tissue samples were immunostained for von Willebrandt factor (Factor VIII) to detect the endothelial cells of capillaries and for a-smooth muscle actin to identify myofibroblasts. For vessel detection cross sections of the samples were determined in three zones (subsynovial, intermediate, and center of the graft). Myofibroblast distribution was analysed in longitudinal sections. Evaluation was performed at 6, 9, 12, 24, 52, and 104 weeks by means of histomorphometry using a digital imaging analysis system. The observations showed that capillary vessels, which originate from the synovial envelope, invaded the avascular graft tissue from the surface toward the center zone. The highest level of vascular density was found after 6 weeks, reaching the vascular status of the native anterior cruciate ligament after 24 weeks. Myofibroblasts were identified in the intact ovine anterior cruciate ligament as well as in the flexor tendon graft prior to implantation. During remodeling first myofibroblasts were found at 6 weeks within newly formed fibre bundles. At 24, 52, and 104 weeks myofibroblast distribution and cell density was similar to that of the intact ovine anterior cruciate ligament. The current study has shown, for the first time, the kinetics of an endoligamentous revascularisation of a free tendon graft at the capillary level. In the current model, the process of revascularisation terminated earlier than previously described. Furthermore the current study has shown that alpha-smooth muscle actin containing fibroblastic cells are a regular part of the intact as well as the remodeled anterior cruciate ligament. There is evidence, that myofibroblasts may be involved in maintaining tissue homeostasis in the mature ligament e.g. by means of crimp formation. The presence of these cells during the early remodeling may further indicate that alpha-smooth muscle actin containing fibroblastic cells are involved in the earliest stages of fibre bundle formation.
Richter, Maximilian. "In vivo gene transfer into mobilized hematopoietic stem cells." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18409.
Full textThe gene therapy of hematopoietic stem cells holds the potential for curative treatment of several otherwise incurable inherited diseases. The majority of current gene therapy treatments relies on the collection of hematopoietic stem cells, their ex vivo modification with retroviral vectors and their transplantation into a myeloconditioned patient. This approach entails several disadvantages, including a reduction of stem cell engraftment potential after ex vivo culture and the potential danger of integrational mutagenesis. In addition, the high costs and complex logistics of this approach limit the access of patients to gene therapeutic regimens. This work explores an alternative approach to hematopoietic stem cell (HSC) gene therapy, termed stem cell in vivo transduction. This approach is based on the mobilization of HSCs from the bone marrow into the peripheral blood and the transduction of the stem cells with adenoviral vectors delivering a transgene as well as a transgene integration machinery. In the first part of this work, it was shown that first-generation adenoviral vectors could be used for the transduction of mobilized HSCs in the periphery of human CD46-transgenic mice. Further, the transduced HSCs were able to home back to the bone marrow and express the transgene. However, over the course of 14 days, a loss of transgene expression in HSCs was observed. To ameliorate these shortcomings, helper-dependent adenoviral vectors encoding a hyperactive Sleeping Beauty transposase for transgene integration were used for stable gene modification of hematopoietic stem cells following intravenous vector administration in mobilized human CD46-transgenic mice. Using this improved vector platform, gene marking of bone marrow HSCs could be observed for extended periods of time (up to 12 weeks). Further, the functionality of the modified HSCs was demonstrated both in colony-forming progenitor assays as well as through the transplantation of gene-modified HSCs into lethally irradiated recipients. Transplantation of modified HSCsled to long-term multi-lineage reconstitution showing that gene-modified stem cells were fully functional. Subsequently the safety of systemic vector administration in mobilized hosts as well as of the Sleeping Beauty-mediated transgene integration was assessed in human CD46- transgenic mice. Lastly, the stem cell in vivo transduction approach was employed in NOG mice transplanted with human CD34+ cells, as well as in Macaca nemestrina non-human primates.
Kießling, Cornelia. "Qualitative Bestimmung von Candida-Spezies in der Mundhöhle bei Patienten nach Herz-, Leber- und Lungentransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/15231.
Full textFor evaluation of Candida carriage, oral swabs were taken from the tongue of 85 patients after liver- (38), heart- (34) and lung transplantation (13) (61 % men, 39 % women, median age: 49 years). Oral candidiasis was found in 21/85 patients (24,7 %) (pseudomembranous form: 15,3 %; erythematous form: 9,4 %; angular cheilitis: 3,5 %). Candida species were cultured in 63/85 patients (74,1 %). C. albicans was the most common isolate (73 %), followed by C. glabrata, C. krusei and C. famata (9,5 %; 6,3 %; 3,2 %). Other isolated species were C. lusitaniae, C. guilliermondii, C. kefyr, C. magnoliae, Pichia ohmeri and C. dubliniensis, the latter being a species first described in oral cavities of HIV-infected individuals. According to the API 20C AUX assimilation profiles seven different phenotypes were identified. No correlation was seen between clinical features and isolated species or biotypes. In patients without antimycotic therapy four different Candida species (C. albicans: 87 %; C. glabrata: 8 %; C. dubliniensis: 3 % and C. famata: 3 %) were identified, whereas, in patients with antifungal therapy eight different Candida species (C. famata, C. guilliermondii, C. kefyr, C. lusitaniae C. magnoliae: 4 %) were isolated. In only 50 % of the latter group C. albicans was detected, while C. glabrata in 17 % and C. krusei in 13 % were identified Long-term therapy and prophylaxis with antifungal agents (amphotericin B; fluconazole/itraconazole) to suppress fungal infections in immunosuppressed patients have contributed to a significant increase in non-albicans-infections because of the high incidence of resistance of the species to these drugs. On the other hand, risk of infection caused by less virulent species is increasing.
Späth, Uta. "Hyperlipidämie nach Nierentransplantation." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2003. http://dx.doi.org/10.18452/14896.
Full textHyperlipidemia is discussed as a risk factor for deterioration of the renal transplant function and the graft loss. We examined the relations between the lipid metabolism and renal transplant function and their connections to factors like immunsuppression, rejections, transplant age und time of dialysis. In the first months of 1996 all patients having a renal transplant were offered an extensive blood control including cholesterol, HDL, LDL, VLDL, triglycerides, apolipoproteins A1, A2, B, Lp(a) und Apo E-Genotype. Afterwards the lipid parameters were put into relation to the clinical course of each patient. We included 201 patients in our study, they were 46,2 ± 11,4 years old. The renal transplantation was in 146 men (72,6 %) und 55 women (27,4 %) 7,7 ± 4,9 years ago. 143 patients got a Cyclosporin A based immunsuppression (71,1 %), 87 patients (43,3 %) were set on lipid lowering therapie. Creatinin 122 ± 86,9 µmol/l; cholesterol 253,6 ± 52,9 mg/dl; Chol/HDL-quotient 5,3 ± 2,3. Creatinin correlates significantly with cholesterol (p < 0,001) and the Chol/HDL-quotient (p < 0,001) - even in the group of patients without lipid lowering therapie (p = 0,001 and p < 0,001) - and LDL, Triglyzeride, VLDL and Apo B. The frequency of rejections did not differ between patients with and without hyperlipidemia. The Apo E-Genotype seems to have no influence on the lipid- and renal metabolism. The lipid parameters our patients correlate in our study significantly with the renal transplant function, but seem to have no influence on the frequency of rejections.
Glanemann, Matthias. "Mechanische und pharmakologische Organkonditionierung im Rahmen warmer Leberischämie." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/13969.
Full textThe present study analyses two strategies to protect from hepatic ischemia-reperfusion injury: ischemic preconditioning (IP) and pharmacologic administration of methylprednisolone (MP). First, the extent of hepatocellular damage after warm liver ischemia induced by cross clamping of the hepatic vessels in the hepatoduodenal ligament (Pringle manöver) was analysed demonstrating comparable tissue protection by both treatment modalities. After 70% partial hepatectomy including Pringle manöver however, the hepatocellular regerneration was markedly decreased after IP treatment, despite reduced ischemia-reperfusion injury. Moreover, MP treatment did not improve hepatic regeneration since it showed a comparable timing to untreated, ischemic controls. In conclusion, both IP and MP significantly reduced hepatic ischemia-reperfusion injury. However, no beneficial effects on hepatocellular regeneration after partial hepatectomy including pringle manöver were observed.
Schön, Michael R. "Transplantation von Lebern nicht-herzschlagender Spender im Schweineleber-Transplantationsmodell." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/13727.
Full textNormothermic extracorporeal liver perfusion (NELP) was studied as a means to pre-serve livers for transplantation and to reverse warm ischemic injury. For the first time we provide experimental evidence that successful transplantation after 4h of normo-thermic extracorporeal liver perfusion is possible and as reliable as 4h of cold preser-vation in University of Wisconsin solution. NELP preserves liver function completely and is capable of reversing 60 min of warm ischemic injury in non heart beating do-nors. 36 German Landrace pigs were transplanted in six groups. Group 1 animals were transplanted directly, group 2 animals after 4h of cold preservation with University of Wisconsin solution and group 3 animals following 4h of normothermic extracorporeal liver perfusion. Group 4 animals sustained 1h of warm ischemia before transplantation of the liver. In group 5 animals were transplanted following 1h of warm ischemia and 4h of cold preservation, and in group 6 after 1h of warm ischemia and 4h of normo-thermic extracorporeal liver perfusion. All animals receiving livers treated by normo-thermic extracorporeal liver perfusion survived without liver failure (group 3 and 6). In contrast, all animals in group 5 developed primary graft non-function within 24 h after transplantation. The technique of NELP holds the potential to keep a mammalian liver outside the body completely functional, possibly for longer than 4h. NELP can be used for liver preservation prior to transplantation or to utilise organs from non-heart-beating donors.
Ewert, Ralf. "Lungenfunktionelle Störungen und interstitielle Lungenveränderungen bei transplantierten Patienten." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2001. http://dx.doi.org/10.18452/13739.
Full textProgress made in transplantation medicine is increasingly leading to longer survival of patients. This means that impairment acquired during the time of chronic illness and side effects during the postoperative course are increasingly significant. Considering pulmonary changes, it was shown that in patients with chronic organ failure (heart, liver, kidneys) impairment of lung function was measurable. This manifests mainly as changes in diffusion, followed by restrictive and obstructive ventilatory impairment. It is to date unclear to what extent interstitial lung disease is involved. This study analyzes the kind, prevalence and extent of lung impairment and the role of interstitial lung disease (ILD) revealed by computed tomography in transplanted patients. For this purpose we examined 79 patients after kidney transplantation (KTX), 40 patients after liver transplantation (LTX) and 40 patients after heart transplantation (HTX) between 45 and 83 months after transplantation by means of comprehensive lung function analysis and high-resolution computed tomography. For purposes of comparison, 75 patients with progressive systemic sclerodermia (chosen because of its exemplary nature for ILD) were evaluated. The study also includes lung function data for 642 patients, an analysis of exercise testing and an autopsy investigation of 73 patients after HTX. The results showed restrictive ventilatory impairment of 2.5-10% in the three groups of transplanted patients. The values for obstruction were similar at between 7.5 and 10%. Taking into account the lung transfer factor (TLCO) and the transfer coefficient (KCO), diffusion impairment was calculated to be 65 and 98% respectively in HTX patients, 44 and 68 % in KTX patients and 32 and 68% in LTX patients. These changes were therefore shown to be significantly more common in patients after HTX than in the other two patient groups. ILD revealed by computed tomography was 5% after LTX, 12% after HTX and 24% after KTX, i.e. a significantly different occurrence was found in patients after LTX and KTX. In none of the groups was a significant correlation between diffusion impairment data and ILD shown. In the sclerodermia group ILD could be shown more often than in the transplanted patients but corresponded in quality. The data of the 642 patients after HTX showed a constant incidence of diffusion impairment independent of the posttransplant time. The analysis of exercise testing established in patients after HTX restricted cardiopulmonary function, of which ventilatory impairment was not the cause. The autopsy investigation of patients after HTX showed widening of the pulmonary interstitium in 56% and changes in the blood vessels in 94% of the cases investigated. The data studied show that diffusion impairment was present to a relevant extent in transplanted patients. This impairment has no causative correlation with the interstitial changes shown by computed tomography to be minimal. Therefore the data support the hypothesis of diffusion impairment in transplanted patients being caused mainly by vascular changes.