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Dive into the research topics where Eckhart Weidmann is active.

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Featured researches published by Eckhart Weidmann.


AIDS | 2000

Virological and immunological effects of treatment interruptions in HIV-1 infected patients with treatment failure.

Miller; Caroline Sabin; Kurt Hertogs; Stuart Bloor; Javier Martinez-Picado; Richard T. D'Aquila; Brendan A. Larder; T Lutz; Peter Gute; Eckhart Weidmann; Holger F. Rabenau; Andrew Phillips; Schlomo Staszewski

ObjectiveTo analyse the immunological and virological effects of treatment interruptions in HIV-1-infected patients with treatment failure and multidrug-resistant virus. MethodsDrug susceptibility was assessed using Antivirogram and genotypic analysis was based on population and clonal sequencing for 48 patients who had interrupted treatment (⩾ 2 months). ResultsTreatment interruption resulted in viral load increases (mean 0.7 log10 copies/ml;P = 0.0001) and CD4 cell count decreases (mean 89 × 106 cells/l;P = 0.0001). A complete shift to wild-type virus at the phenotypic, genotypic and clonal level was observed in 28/45 patients. These patients differed from those that did not show a shift to wild type in baseline CD4 cell counts (192 versus 59 × 106 cells/l;P = 0.007) and in the relationship between baseline viral load and CD4 cell count (no correlation versus a significant negative correlation;P = 0.008). Response to re-initiation of treatment fell with increasing viral load [relative hazard (RH) 0.33;P = 0.001] and with increasing total number of drugs with reduced susceptibility (RH 0.51;P = 0.0003); it improved with the number of new drugs received (RH 2.12;P = 0.0002) and a shift to wild type (RH 5.22, P = 0.006). ConclusionsChanges in surrogate markers suggest that treatment provided benefit in spite of virological failure and resistant virus. Although patients with a shift to wild-type virus responded better in the short term to treatment re-initiation, the long-term effects are not known and the risk of immune deterioration needs to be carefully considered.


Annals of Oncology | 1998

High expression of bcl-2 mRNA as a determinant of poor prognosis in acute myeloid leukemia

T. Karakas; Ulrich Maurer; Eckhart Weidmann; Cornelius Miething; Dieter Hoelzer; Lothar Bergmann

BACKGROUND The bcl-2 oncoprotein is suggested to be directly involved in the emergence of drug resistance by disrupting or delaying the apoptotic program and promoting tumor survival. PATIENTS AND METHODS In order to define the clinical relevance of the bcl-2 mRNA expression in acute myeloid leukemia (AML) and its correlation to therapy outcome and prognosis, we analyzed 219 AML bone marrow (BM) samples, including 119 patients with de novo AML at presentation, 37 with AML following myelodysplastic syndrome (MDS), as well as 42 BM samples of AML in relapse and 21 in complete remission (CR) using RT-PCR. For performing quantitative measurements of bcl-2 mRNA, we developed a quantitative RT-PCR. RESULTS Bcl-2 mRNA was detectable in 133 of 156 (84%) patients at diagnosis and 40 of 42 (95%) at relapse. AML patients with high bcl-2 mRNA expression achieved lower CR rates than those with no or low expression. Concerning the long-term outcome, the overall (OS) and disease-free survival (DFS) was significantly worse in AML patients with high expression levels of bcl-2 mRNA. The three-year OS for all newly diagnosed AML patients was 49% and 10% (P = 0.028), respectively, and 71% and 15% (P = 0.0004) for patients < 60 years. Comparable significant differences were observed for the DFS. In AML following MDS and patients > 60 years, the bcl-2 expression was not associated with remission rate or survival. CONCLUSIONS The expression of bcl-2 mRNA may serve as a prognostic factor predicting remission outcome and long-term prognosis in AML.


AIDS | 1999

Virological response to protease inhibitor therapy in an HIV clinic cohort.

Schlomo Staszewski; Veronica Miller; Caroline Sabin; Amina Carlebach; Anna-marie Berger; Eckhart Weidmann; Eilke B. Helm; Andrew Hill; Andrew Phillips

OBJECTIVE New antiretroviral strategies aim to reduce plasma HIV RNA (viral load) to below the limits of detectability of assays with the objective of reducing viral replication in order to stop or reverse the pathogenic process and prevent development of drug resistance. First use of a protease inhibitor might offer the most realistic chance of achieving this aim. Our objective was to study the virological response to protease inhibitors in patients taking them for the first time. METHODS A total of 901 patients from a large outpatient clinic were followed a mean of 15 months from the time of starting a protease inhibitor until 1 May 1998. Viral load and CD4 cell count measurements were made on average every 34 days. RESULTS Overall there was a 79% [95% confidence interval (CI), 76-82] probability of the patients achieving a viral load < 500 copies/ml by 24 weeks after starting the protease inhibitor. In a multiple Cox regression model, those with lower initial viral load [relative hazard (RH), 0.72; P < 0.0001], higher CD4 cell count (RH, 1.07; P = 0.002), those starting other new drugs at same time as the protease inhibitor (RH, 1.46 for two versus none; P = 0.003), those who were antiretroviral-naive, and those using indinavir or nelfinavir were more likely to achieve such levels. In those 651 patients achieving viral load < 500 copies/ml within 24 weeks, there was an estimated 53% (95% CI, 51-55) probability of rebound of viral load to > 500 copies/ml by 52 weeks from the first undetectable value. Again, those who had started other new drugs at the same time as the protease inhibitor (RH, 0.57; P = 0.003 for starting two versus none) tended to experience a lower probability of viral load rebound, as did those with higher initial CD4 cell count (RH, 0.87 per 100 x 10(6)/l higher; P = 0.0007). Those who took saquinavir achieved less durable virological responses than those who took other protease inhibitors. CONCLUSIONS Starting protease inhibitor therapy with two other new antiretroviral drugs simultaneously with protease inhibitor therapy offers a better best chance of achieving sustained viral load < 500 copies/ml than starting fewer new drugs.


Leukemia & Lymphoma | 1999

Positron Emission Tomography (PET) for Staging and Evaluation of Response to Treatment in Patients with Hodgkin's Disease

Eckhart Weidmann; Bianca B. Aican; Andreas Hertel; Richard P. Balm; Kaiu Chow; Bernhard Knupp; Stefan Adams; Hör G; Dieter Hoelzer; Paris S. Mitrou

Forty two examinations utilizing F-18 FDG-PET were performed in 23 patients with Hodgkins disease to study for involved lymphoma regions and compared to conventional staging procedures. Twenty stagings were performed at diagnosis of untreated Hodgkins disease or at first relapse, and 22 restagings during and after chemoradiotherapy. At diagnosis in 5 of 20 patients PET and other procedures revealed different extranodal manifestations and in 3 patients established different clinical staging. PET seemed to be accurate in the assessment of lymphoma involvement in nodal sites. During follow up, in 10 out of 22 investigations different results and discrepancy were recorded, mostly due to the different extent of F-18-FDG metabolism in residual masses in lymphatic tissues compared to CT, X-ray or ultrasonography. The results indicate that PET may have advantages in the assessment of remissions in nodal sites. Less conclusive results were observed with regard to extranodal involvement or inflammatory disease. In conclusion PET may be sufficient for the staging of the majority of patients with Hodgkins disease and particularly for assessing remission status in nodal sites, but PET may have disadvantages in the evaluation of extranodal lymphoma and inflammatory disease.


Annals of Hematology | 1995

Lactate dehydrogenase-release assay: A reliable, nonradioactive technique for analysis of cytotoxic lymphocyte-mediated lytic activity against blasts from acute myelocytic leukemia

Eckhart Weidmann; Jürgen Brieger; B. Jahn; Dieter Hoelzer; Lothar Bergmann; Paris S. Mitrou

Treatment of patients in remission of acute myelocytic leukemia using immunotherapy with interleukin 2 is a new approach to prolonging remission duration in this disease. As an important mechanism for the pathophysiology of eradication of residual myelocytic blast populations, activation of cytotoxic effector lymphocytes has frequently been discussed. However, the associated immunological research has been complicated to some extent, because in conventional chromium 51-release assays, blast cells frequently fail to incorporate sufficient amounts of51Cr and/or spontaneously release high amounts of51Cr. Recently, we established a culture system which promotes the out-growth of cytotoxic T lymphocytes in bone marrow-derived mononuclear cells cultured in IL-2. To study cytotoxicity and the responsible mechanisms of the obtained T-cell lines and clones, we modified a previously described cytotoxicity assay, based on the release of lactate dehydrogenase (LDH-release assay) for use in cryopreserved blasts obtained from the bone marrow of patients with acute myelocytic leukemia. Using this assay, we were able to detect cytotoxicity of IL-2-activated peripheral blood lymphocytes from three healthy controls against a number of blast samples obtained from the bone marrow of patients with AML (up to more than 40% lysis at an effector target cell ratio of 20∶1). However, a minority of AML blasts seem to be resistant to lysis by IL-2-activated lymphocytes. In bone marrow-derived T-cell lines from patients with AML we detected lytic activity against autologous blasts in three of seven cases tested by LDH release, ranging from 29 to 63% at an effector target ratio of 10∶1. Additionally, T-cell clones with different phenotypes were established which were able to mediate cytotoxicity against autologous blast cells. Thus, cytotoxicity against freshly isolated blasts from patients with acute myelocytic leukemia can be analyzed reliably, reproducibly, and without the use of isotopes by the LDH-release assay.


The Journal of Infectious Diseases | 1999

CD4 Lymphocyte Count as a Predictor of the Duration of Highly Active Antiretroviral Therapy—Induced Suppression of Human Immunodeficiency Virus Load

Veronica Miller; Schlomo Staszewski; Caroline Sabin; Amina Carlebach; Carsten Rottmann; Eckhart Weidmann; Holger F. Rabenau; Andrew Hill; Alessandro Cozzi Lepri; Andrew N. Phillips

The association between CD4 cell count and duration of virus load suppression was investigated in 558 patients in the Frankfurt HIV Clinic Cohort who had begun highly active antiretroviral therapy and who had virus load declines to </=500 copies/mL. The Kaplan-Meier method estimated viral rebound in 42.5% of patients by 24 weeks and in 64.3% by 84 weeks. Risk of viral rebound was independently associated with baseline and changes from baseline CD4 cell count. The achieved CD4 cell count was the most important factor for prediction of viral rebound (relative hazard, 5.4 for an updated CD4 cell count of <20 vs. >500 copies/mL; P=.0001). Baseline virus load was not associated with virus load rebound. Lower baseline CD4 cell counts were associated with increased risk of viral rebound; however, this risk was significantly reduced in persons with low baseline CD4 cell counts who experienced substantial increases in CD4 cell counts during follow-up.


Leukemia | 2002

The coexpression of the apoptosis-related genes bcl-2 and wt1 in predicting survival in adult acute myeloid leukemia.

T. Karakas; Cornelius Miething; Ulrich Maurer; Eckhart Weidmann; Ackermann H; Dieter Hoelzer; Lothar Bergmann

The Wilms tumor gene wt1 and the protooncogene bcl-2 are upregulated in acute myeloid leukemia (AML) and are known to regulate or to inhibit the onset of apoptosis. Since wt1 has been shown to regulate the expression of bcl-2, we investigated the association of the expression of these genes and their prognostic relevance in AML. Leukemic blasts from the bone marrow of 152 patients with newly diagnosed AML were analyzed for bcl-2 and wt1 mRNA expression using RT-PCR and quantitative PCR. Therapy outcome was correlated with the level of bcl-2 and wt1 transcripts. Bcl-2-specific mRNA was detectable in 127/152 (84%) patients and wt1 mRNA in 113/152 (74%) patients with AML. In monocytic subtypes the frequency of bcl-2 and wt1 transcripts was significantly lower. The expression of bcl-2 mRNA was correlated significantly with that of wt1 mRNA (P < 0.0001). In AML patients <60 years, high expression of bcl-2 and wt1 was associated with a reduced rate of continuing complete remission (CCR, P = 0.002 and P = 0.005, respectively) and increased death rate (P = 0.0002 and P = 0.04, respectively) in contrast to patients >60 years, where the expression of bcl-2 or wt1 had no prognostic impact. Based on the coexpression of bcl-2 and wt1, we established a prognostic model defining three risk groups with significant differences in CCR rate (P = 0.01), overall survival (P < 0.04) and disease-free survival (P < 0.03). Thus, bcl-2 and wt1 mRNA expression are associated with response and long-term outcome in AMLs. The coexpression of these genes allows determination of prognostic groups with high predictive value for overall and disease-free survival.


Leukemia & Lymphoma | 2009

A novel regimen combining high dose cytarabine and bortezomib has activity in multiply relapsed and refractory mantle cell lymphoma - long-term results of a multicenter observation study.

Oliver Weigert; Eckhart Weidmann; Rudolf Mueck; Martin Bentz; Christoph von Schilling; Robert Rohrberg; Kathleen Jentsch-Ullrich; Wolfgang Hiddemann; Martin Dreyling

Salvage therapy for patients with mantle cell lymphoma (MCL) remains a challenge. The clinical course is characterised by increasing resistance to conventional chemotherapy and a dismal long-term outcome. On the basis of studies demonstrating synergy in vitro, eight heavily pretreated patients (median age 65 years) with advanced stage MCL were individually treated with a novel combination protocol consisting of the proteasome inhibitor bortezomib (1.5 mg/m2; Days 1 and 4), high-dose cytarabine (750–2000 mg/m2; Days 2 and 3) and dexamethasone (40 mg daily; Days 1–4). Rituximab (375 mg/m2) was added in patients not refractory to prior rituximab-containing regimens. Treatment was repeated in 3-week intervals or postponed until hematologic recovery for up to four planned cycles. Toxicity consisted mainly of Grade 3/4 hematotoxicity, which occurred in all patients. Median treatment interval was 31 days. Objective responses were observed in four (50%) of eight patients, including two complete remissions. Median progression free and overall survival were 5 and 15.5 months, respectively. The combination of bortezomib and a high-dose cytarabine-containing regimen has activity in heavily pretreated patients with relapsed or refractory MCL.


Biochemical Pharmacology | 2003

Synergistic effects of chemotherapeutic drugs in lymphoma cells are associated with down-regulation of inhibitor of apoptosis proteins (IAPs), prostate-apoptosis-response-gene 4 (Par-4), death-associated protein (Daxx) and with enforced caspase activation

Kai Uwe Chow; Daniel Nowak; Simone Boehrer; Martin Ruthardt; Andrea Knau; Dieter Hoelzer; Paris S. Mitrou; Eckhart Weidmann

Cytotoxic drugs mediate apoptotic tumor cell death by influencing key regulator proteins of programmed cell death. In clinical practice cytotoxic drug combinations are desired to potentiate tumor cell kill and to minimize side effects. Nevertheless, the molecular mechanisms underlying synergistic and antagonistic effects on tumor cells are still poorly understood. In order to elucidate these molecular mechanisms we established models of synergistic and antagonistic drug combinations within the same lymphoma cell lines. By combination index method we demonstrated that bendamustine in combination with either doxorubicin or mitoxantrone caused antagonistic effects on disruption of mitochondrial membrane potential as well as on the rate of apoptosis. In contrast the combination of bendamustine with cladribine acted synergistically on these parameters. By using the IC(50) (dosages causing 50% rate of apoptosis) the synergistic effect of the combination of bendamustine and cladribine was associated with an enhanced mitochondrial release of cytochrome c and Smac/DIABLO, by down-regulation of x-linked inhibitor of apoptosis (XIAP), cIAP1, Par-4 and Daxx as well as by a significantly increased activation of caspases-3, -6, -7, -8 and -9. At the same rate of apoptosis (IC(50)), the antagonistic combinations did not increase the release of cytochrome c or Smac/DIABLO, nor down-regulate the expression of XIAP, cIAP1, Par-4 and Daxx, nor increase the activation of caspases. The role of down-regulation of IAPs and of enforced caspase activation for synergism in this model was supported by the observation, that broad spectrum inhibition of caspases re-established expression of XIAP. Our study is the first to outline the molecular alterations caused by synergistic and antagonistic drug combinations within the same lymphoma cell model. The above described mechanisms were already assessable at a point where the effects of synergistic or antagonistic combinations could not yet be discriminated quantitatively by the level of apoptosis rate of the lymphoma cells.


Leukemia & Lymphoma | 1996

Peripheral T-cell Lymphomas Respond Well to Vincristine, Adriamycin, Cyclophosphamide, Prednisone and Etoposide (VACPE) and Have a Similar Outcome as High-Grade B-Cell Lymphomas

T. Karakas; Lothar Bergmann; H. J. Stutte; Elke Jäger; A. Knuth; Eckhart Weidmann; Paris S. Mitrou; Dieter Hoelzer

Peripheral T-cell lymphomas (PTCL) represent a heterogeneous group of T-cell malignancies including subentities with favourable (large cell anaplastic) or unfavourable (pleomorphic) prognosis. The clinical outcome of PTCL has been controversially discussed, but a worse prognosis than high-grade B-cell Non-Hodgkins lymphomas (NHL) has been postulated by most authors. In this report we summarize the results of a prospective comparative study investigating the therapy outcome of 27 patients (pts) with PTCL and 55 pts. with high grade B-cell NHL and give an overview of therapy studies in PTCL. The histological subtypes were 14 pleomorphic, 8 large-cell anaplastic (Ki-1+), 2 angioimmunoblastic (AILD) and 3 other PTCL. In three patients the PTCL was associated with non-tropical sprue (11%). Nineteen patients presented with an advanced stage of disease (stage III and IV, 70%), 17 (63%) pts. had B-symptoms. The patients were treated with vincristine 2 mg d1, adriamycin 25 mg/m2 d1-3, cyclophosphamide 800 mg/m2 d1, prednisone 60 mg/m2 d1-7 and etoposide 120 mg/m2 d1-3 (VACPE). In 77% of pts. with PTCL and 84% of patients with high-grade B-cell NHL a complete remission (CR) was achieved. 75% of the complete responders with PTCL and 70% with B-NHL are still in ongoing CR. The subgroup of large-cell anaplastic attained a CR in 88%. The median observation time is 44 months (1(+)-77+). The probability of 1-, 3- and 5-year overall and disease-free survival for the T-cell group were 76%, 54%, 48% and 76%, 62%, 62%, respectively according to Kaplan-Meier. There was no significant difference regarding the remission rate, the overall-, event-free or disease-free survival compared to high-grade B-cell lymphomas. In conclusion, the VACPE regimen is an effective and feasible regimen in the management of PTCL achieving complete remissions in a large proportion of patients.

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Dieter Hoelzer

Goethe University Frankfurt

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Paris S. Mitrou

Goethe University Frankfurt

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Lothar Bergmann

Goethe University Frankfurt

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Jürgen Brieger

Goethe University Frankfurt

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Kai U. Chow

Goethe University Frankfurt

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Simone Boehrer

Goethe University Frankfurt

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T. Karakas

Goethe University Frankfurt

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Daniela K. Schui

Goethe University Frankfurt

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Klaus Fenchel

Goethe University Frankfurt

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