Browsing by Author "Ott, M."

The purpose of this study was to try to determine by means of contrast-enhanced MRI, a subset of patients with Graves' ophthalmopathy who will not respond to orbital radiotherapy. 54 patients with Graves' ophthalmopathy were treated with orbital radiotherapy (10 x 2 Gy) and symptom relief was recorded. MRI examinations prior to radiotherapy were retrospectively evaluated for enlargement, contrast enhancement and fibrotic changes in extraocular muscles and surrounding soft tissue. Imaging data were correlated with clinical features and response. Symptom relief was observed in 61% of patients but this could not be predicted by any of the MRI signs investigated. However, there is a trend for a better treatment reponse in patients who show contrast enhancement of extraocular muscles prior to orbital radiotherapy (p=0.08). MR1 could not adequately predict the efficacy of orbital radiotherapy in this group of patients. Clinical assessment of disease activity is still the most reliable method.

Purpose: High-dose therapy (HDT) is currently under investigation for patients with advanced Low-grade non-Hodgkin lymphoma (NHL). We report on the toxicity of a modified HDT that combines total-body irradiation (TBI) with involved-field irradiation (IF-RT) for patients with bulky disease or residual lymphomas >2 cm after induction chemotherapy. Patients and Methods: 41 patients received HDT which consisted of high-dose cyclophosphamide and fractionated TBI (6 x 2 Gy) followed by autologous stem cell transplantation. Eleven patients received IF-RT prior to TBI, three patients had already received another radiotherapy treatment prior to HDT. Results: After a medium follow-up of 19 months we observed an overall survival rate of 100%, and a relapse-free survival rate of 78%. Severe toxicity was observed only in one patient who developed a myelodysplastic syndrome, and another patient who showed signs of pneumonitis. About two thirds of the patients claimed minor toxicity of grade I-II according the LENT-SOMA scale, predominantly as a decrease in concentration, reduced sexual functioning, and musculo-skeletal pain. Correspondingly, Laboratory tests showed grade I-II changes of blood counts, Liver enzymes, hormone levels, and lung function. There was no excess toxicity in the patients who received IF-RT additional to TBI. Conclusions: HDT including TBI and prior IF-RT is feasible without excess morbidity. Careful follow-up is required to detect myelodysplastic syndrome or endocrine changes of ovarian or testicular function.

In recent years the interest in liver cell therapy has been increasing continuously, since the demand for whole liver transplantations in human beings far outweighs the supply. From the clinical point of view, transplantation of hepatocytes or hepatocyte-like cells may represent an alternative to orthotopic liver transplants in acute liver failure, for the correction of genetic disorders resulting in metabolically deficient states, and for late stage liver disease such as cirrhosis. Although the concept of cell therapy for various diseases of the liver is widely accepted, the practical approach in humans often remains difficult. An international expert panel critically discussed the recent published data on clinical and experimental hepatocyte transplantation and the possible role of stem cells in liver tissue repair. This paper aims to summarise the present status of cell based therapies for liver diseases and to identify areas of future preclinical and clinical research. (c) 2006 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Hepatocyte transplantation is regarded as a promising option to correct hereditary metabolic liver disease. This study describes a novel method involving regional transient portal ischemia (RTPI) in combination with hepatic irradiation (IR) as a preparative regimen for hepatocyte transplantation. The right lobules of rat livers (45% of liver mass) were subjected to RTPI of 30-120 min. Liver specimens and serum samples were analyzed for transaminase levels, DNA damage, apoptosis, and proliferation. Repopulation experiments involved livers of dipeptidylpeptidase IV (DPPIV)-deficient rats preconditioned with RTPI (60-90 min) either with or without prior partial hepatic IR (25 Gy). After reperfusion intervals of 1 and 24 h, 12 million wild-type (DPPIV positive) hepatocytes were transplanted into recipient livers via the spleen. RTPI of 60-90 min caused limited hepatic injury through necrosis and induced a distinct regenerative response in the host Twelve weeks following transplantation, small clusters of donor hepatocytes were detected within the portal areas. Quantitative analysis revealed limited engraftment of 0.79% to 2.95%, whereas control animals (sham OP) exhibited 4.16% (determined as relative activity of DPPIV when compared to wild-type liver). Repopulation was significantly enhanced (21.43%) when IR was performed prior to RTPI, optimum preconditioning settings being 90 min of ischemia and 1 h of reperfusion before transplantation. We demonstrate that RTPI alone is disadvantageous to donor cell engraftment, whereas the combination of IR with RTPI comprises an effective preparative regimen for liver repopulation. The method described clearly has potential for clinical application.

Polymerase chain reaction (PCR) assessment of clonal immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements is an important diagnostic tool in mature B-cell neoplasms. However, lack of standardized PCR protocols resulting in a high level of false negativity has hampered comparability of data in previous clonality studies. In order to address these problems, 22 European laboratories investigated the Ig/TCR rearrangement patterns as well as t(14; 18) and t( 11; 14) translocations of 369 B-cell malignancies belonging to five WHO-defined entities using the standardized BIOMED-2 multiplex PCR tubes accompanied by international pathology panel review. B-cell clonality was detected by combined use of the IGH and IGK multiplex PCR assays in all 260 definitive cases of B-cell chronic lymphocytic leukemia (n = 56), mantle cell lymphoma ( n 54), marginal zone lymphoma ( n 41) and follicular lymphoma ( n 109). Two of 109 cases of diffuse large B-cell lymphoma showed no detectable clonal marker. The use of these techniques to assign cell lineage should be treated with caution as additional clonal TCR gene rearrangements were frequently detected in all disease categories. Our study indicates that the BIOMED-2 multiplex PCR assays provide a powerful strategy for clonality assessment in B-cell malignancies resulting in high Ig clonality detection rates particularly when IGH and IGK strategies are combined.