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E Holler

Publications and source records attributed to E Holler.

At least 19 recordsLinked to original sources
PubMed2006

Thermal decomposition of fungal poly(beta,L-malic acid) and Poly(beta,L-malate)s.

The thermal decomposition of poly(beta,l-malic acid), poly(alpha-methyl beta,l-malate), and ionic complexes of the polyacid with alkyltrimethylammonium salts was studied by TGA, GPC, and FTIR and NMR spectroscopy. It was found that poly(beta,l-malic acid) depolymerized above 200 degrees C by an unzipping mechanism with generation of fumaric acid which is then partially converted in a mixture of maleic acid and anhydride. On the contrary, random scission of the main chain was found to happen in the thermal decomposition of poly(alpha-methyl beta,l-malate). On the other hand, ionic poly(beta,l-malate)s degraded through a well defined three-stage process, the first one being depolymerization of the poly(malate) main chain along with decomposition of the ionic complex. Decomposition of the previously generated alkyltrimethylammonium salts followed by unspecific cracking of the resulting nitrogenated compounds happened at higher temperatures. Mechanisms partially explaining the decomposition processes of the three studied systems were proposed according to collected data.

Chromatography, Gel↗
PubMed2006

Assessing the potential role of photopheresis in hematopoietic stem cell transplant.

The First International Symposium on Photopheresis in Hematopoietic Stem Cell Transplantation was held in Vienna, Austria with an educational grant from Therakos Inc. from 25 May to 27 May 2005. Three general issues were addressed: (1) pathophysiology of graft-versus-host disease (GvHD), (2) induction of immune tolerance and the immunology of phototherapy and (3) current standard treatment and prevention strategies of acute and chronic GvHD and the use of extracorporeal photopheresis (ECP). The objectives of the meeting were to open a dialogue among leading researchers in photobiology, immunology, and hematopoietic stem cell transplantation; foster discussions and suggestions for future studies of the mechanism of action of ECP in acute and chronic GvHD; and promote collaboration between basic scientists and clinicians. As can be seen from the summaries of the individual presentations, important advances have been made in our understanding of GvHD, including the use of photoimmunology interventions and the development of robust model systems. It is our expectation that data from photoimmunology studies can be used to generate hypotheses in animal models that can further define the mechanism of action of ECP and help translate the findings to clinical trials of ECP for the prophylaxis and treatment of both chronic and acute GvHD.

Graft vs Host Disease↗
PubMed2006

Replacement of calcineurin inhibitors with daclizumab in patients with transplantation-associated microangiopathy or renal insufficiency associated with graft-versus-host disease.

Transplantation-associated microangiopathy (TAM) or renal insufficiency (RI) after allogeneic hematopoietic stem cell transplantation is associated with a high mortality. As calcineurin inhibitors (CI) may contribute to TAM or RI, we evaluated the efficacy of replacing CI by daclizumab in patients with graft-versus-host disease (GVHD). Thirteen patients with GVHD-associated TAM and five patients with RI were treated with daclizumab 1 mg/kg intravenous (i.v.)/week, discontinuation of the CI and continuation of the remaining GVHD treatment. All patients had acute GVHD (steroid-sensitive (n=4), steroid-refractory (n=10)) or chronic GVHD (n=4) and were treated with CI before the start of daclizumab. Nine of 13 patients with TAM treated with daclizumab and discontinuation of CI achieved complete remission of TAM, two had stable disease, and one patient did not respond. Patients receiving daclizumab for RI without TAM showed stabilization (2/5) or improvement (3/5) of renal function. Four of 14 patients with acute GVHD achieved CR, two partial remission, eight patients did not respond and 11/14 died at a median of 39 days after start of the daclizumab. Our data demonstrate that replacement of CI by daclizumab can improve TAM and RI. However, mortality remains high in patients with acute GVHD.

Acute Disease↗
PubMed2005

Use of intrathecal prophylaxis in allogeneic haematopoietic stem cell transplantation for malignant blood diseases: a survey of the European Group for Blood and Marrow Transplantation (EBMT).

SUMMARY: A survey was carried out among EBMT centres to describe the current practice concerning intrathecal (i.t.) prophylaxis in allogeneic stem cell transplantation for malignant diseases in patients with no central nervous system (CNS) manifestations of the disease at any time. A total of 90 centres reported their practice: 42 centres (47%) never used pre-transplant i.t. prophylaxis as part of the conditioning, whereas 48 centres (53%) gave i.t. prophylaxis to selected groups. The main indications were acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), and lymphoma (53, 33, and 23% of all centres, respectively). Prophylaxis was usually given to all patients with ALL, but often restricted to high-risk patients in AML and lymphoma. Of the 90 centres, 29 (32%) gave prophylactic i.t. treatment after the transplantation, mainly for the same indications as pre-transplant. This survey illustrates the heterogeneity in the current practice of i.t. prophylaxis in allogeneic transplantation for malignant blood disorders in Europe. The documentation in the literature to support the use of i.t. prophylaxis as part of transplantation for malignant diseases in patients without preceding CNS involvement is sparse. Based on the rarity of isolated CNS relapse after allogeneic stem cell transplantation, EBMT does not recommend routine i.t. prophylaxis to patients without prior CNS involvement.

Antineoplastic Agents↗
PubMed2005

Dose-escalated treosulphan in combination with cyclophosphamide as a new preparative regimen for allogeneic haematopoietic stem cell transplantation in patients with an increased risk for regimen-related complications.

Treosulphan has recently demonstrated antileukaemic activity and potent haematopoietic stem cell toxicity. Dose-escalated treosulphan (3 x 12 or 3 x 14 g/m2) combined with cyclophosphamide (Cy) was chosen for a new preparative regimen before allogeneic haematopoietic stem cell transplantation in 18 patients (median age 44, range 19-64 years) with haematological malignancies, considered ineligible for other myeloablative preparative regimens. Pharmacokinetic studies demonstrated rapid treosulphan plasma clearance and a dose-dependent increase of its maximum plasma concentrations and area under the concentration-time curves. Rapid and sustained white blood cell and platelet recovery and full donor chimerism was attained in all evaluable patients. Nonhaematological regimen-related CTC grades 3-4 adverse events were transient and predominantly consisted of cardiac (28%), gastrointestinal (39%), and hepatic (39%) toxicities. The 1-year nonrelapse mortality was 22%. Principal causes of transplant-related lethal events were infections in three of four affected patients. Only one patient died from regimen-related cardiac toxicity. The 1-year relapse estimate is 22%, overall and progression-free survival estimates are 67 and 56%, respectively. In conclusion, this new treosulphan and Cy combination is an effective, comparatively well-tolerated myeloablative preparative regimen even in patients with an increased risk for regimen-related toxic complications.

Adult↗
PubMed2005

Treatment of steroid-resistant acute graft-versus-host disease with daclizumab and etanercept.

Steroid-resistant acute GVHD (aGVHD) following allogeneic hematopoietic stem cell transplantation (alloHSCT) continues to be associated with a high mortality. We report the results of a phase II study of treatment of steroid-resistant aGVHD with the IL-2 receptor antibody daclizumab combined with the TNF-receptor fusion protein etanercept. Treatment consisted of daclizumab 1 mg/kg given i.v. on days 1, 4, 8, 15, 22 and etanercept 16 mg/m(2) s.c. on days 1, 5, 9, 13, 17. A total of 21 patients (age 15-61 years) with steroid-resistant aGVHD after alloHSCT were included in the study. Donor types were HLA-matched related (n=6), HLA-matched unrelated (n=14), and HLA-mismatched unrelated (n=1). Eight patients achieved complete, and six showed partial remission of aGVHD. Seven patients did not respond. Four of 21 patients are currently alive with a median follow-up of 586 (185-1155) days. Three patients died due to relapsed malignancy. Treatment-related mortality was due to infectious complications (n=11) or organ failure due to aGVHD (n=3). In total, 12 patients developed subsequent chronic GVHD. In conclusion, the data demonstrate an acceptable response rate of the combination of daclizumab and etanercept in the treatment of steroid-resistant aGVHD. Nevertheless, long-term mortality due to infectious complications and chronic GVHD remains high.

Acute Disease↗
PubMed2005

Oligotide, a defibrotide derivative, protects human microvascular endothelial cells against fludarabine-induced activation, damage and allogenicity.

Fludarabine is a nonmyeloablative immunosuppressant increasingly used as a component of alternative reduced-intensity conditioning regimens prior to allogeneic stem cell transplantation (SCT). However, we have previously shown that 2-fluoroadenine 9-beta-D-arabinofuranoside (F-Ara) as the active metabolized form of fludarabine induces damage, activation and allogenicity in human microvascular endothelial cells (HMEC). We had also identified the pharmaceutic compound Defibrotide (DF), originally used in the treatment of veno-occlusive disease and thrombotic microangiopathy, as being protective against F-Ara-induced dysfunction of HMEC, importantly, without affecting the antileukemic effect of F-Ara. In the present report, we show that a recently developed derivative of DF, Oligotide, similarly downregulates F-Ara-induced activation and damage of HMEC as well as their antigenicity for allogeneic CD8+ T cells. In addition, Oligotide could also block F-Ara-mediated transendothelial migration of peripheral blood cells across the HMEC barrier. Taken together, these observations argue for a potential clinical use of both DF and Oligotide in pre transplant conditioning.

Antineoplastic Agents↗
PubMed2005

Protein C and procollagen III peptide levels in patients with hepatic dysfunction after allogeneic hematopoietic stem cell transplantation.

Veno-occlusive disease (VOD) is one of the most serious complications following hematopoietic stem cell transplantation (HSCT) and is associated with a high mortality. We conducted a large trial on the clinical significance of protein C (PC) and procollagen III peptide (PNPIII) levels, which have been described as possible diagnostic markers of VOD. In total, 350 patients undergoing allogeneic HSCT were included. PC and PNPIII levels were analyzed prior to conditioning and weekly until 8 weeks after the HSCT. Signs of VOD and other transplantation-related complications (graft-versus-host disease (GVHD), toxicity, microangiopathic hemolytic anemia, infection) were recorded weekly throughout the trial. Patients showed a significant drop of the PC levels in VOD (70.3 vs 96.3%, P<0.001) and with increasing severity of aGVHD. Steroids increased the PC levels (69.4% vs 109.4%, P<0.001). The highest PNPIII levels were registered in patients with VOD (mean 6.3 IU/ml). Patients with aGVHD showed an elevation of PNPIII, especially patients with hepatic aGVHD. PC levels during conditioning do not predict VOD (98.5 vs 76.5%, NS). Although PC and PNPIII may play a role in the pathogenesis of VOD they cannot discriminate between complications with jaundice and are only of limited help in the differential diagnosis of VOD.

Adolescent↗
PubMed2005

OKT3 muromonab as second-line and subsequent treatment in recipients of stem cell allografts with steroid-resistant acute graft-versus-host disease.

We retrospectively evaluated response to monoclonal antibody directed against CD3 (OKT3) treatment in 43 patients with steroid-resistant acute graft-versus-host disease (aGvHD) following allogeneic hematopoietic cell transplantation. Median duration of OKT3 therapy was 9 (range, 1-20) days. In all, 20 cycles were administered as second-line and 28 as third-plus line treatment. Side effects were mild to moderate. Overall response rate was 69 with 12% complete remissions and best response in skin involvement. Proportional reduction of concomitant steroids was higher in responding patients. Five patients (12%) achieved durable responses. Pharmacokinetic studies of OKT3 showed adequate plasma levels (> or = 1000 ng/ml) in 13 of 17 evaluable patients after a median of 6 (1-11) days on treatment. OKT3 became undetectable shortly after discontinuation of therapy. Median survival for all patients was 80 (2 to 2474+) days. There was a trend for better survival for patients on second-line vs third-plus line treatment (146 vs 46 days; P=0.07) and significant longer survival for patients with grade II when compared to those with grade III/IV aGvHD (206 vs 47 days; P=0.039). We conclude that salvage treatment with OKT3 shows considerable efficiency, however, sometimes of transient nature, and is well tolerated in patients with corticosteroid-resistant aGvHD.

Adolescent↗
PubMed2005

Interferon (IFN)-gamma is a main mediator of keratinocyte (HaCaT) apoptosis and contributes to autocrine IFN-gamma and tumour necrosis factor-alpha production.

BACKGROUND: Apoptosis of keratinocytes or intestinal epithelial cells is an important pathophysiological mechanism of organ damage during acute graft-versus-host disease. OBJECTIVES: To analyse in detail the mediators and their mutual interaction leading to keratinocyte apoptosis. METHODS: Experiments were performed using a keratinocyte cell line (HaCaT) and human skin explant cultures. RESULTS: Supernatants (SN) of major histocompatibility complex nonmatched mixed lymphocyte cultures (MLCs) induced apoptosis in HaCaT cells and also in keratinocytes from skin biopsies. Although both interferon (IFN)-gamma and Fas ligand (FasL) were detected in MLC-SN by enzyme-linked immunosorbent assay, the apoptosis-inducing capacity could be fully abrogated by neutralization of IFN-gamma, but not by neutralization of FasL. Recombinant (r) IFN-gamma induced HaCaT keratinocyte apoptosis in a dose- and time-dependent manner. Induction of HaCaT apoptosis by rFasL alone was induced only at higher doses than present in MLC-SN, but apoptosis was dramatically enhanced in the presence of rIFN-gamma. Further synergistic effects with IFN-gamma in the induction of apoptosis were also observed with agonistic antitumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptor 2 antibody, soluble TRAIL and TNF-alpha. However, in contrast to FasL and TRAIL, TNF-alpha alone did not induce HaCaT apoptosis. Interleukin-1beta and lipopolysaccharide did not enhance the apoptosis-inducing effect of IFN-gamma. Beside its apoptosis-inducing capacity in HaCaT cells, rIFN-gamma also induced autocrine IFN-gamma production, and combined treatment with IFN-gamma and TNF-alpha induced autocrine TNF-alpha production. Neutralization of autocrine IFN-gamma protected HaCaT cells from apoptosis. CONCLUSIONS: Taken together, our data suggest a central role for IFN-gamma in HaCaT keratinocyte apoptosis but also show the importance of co-acting mediators such as TNF-alpha, TRAIL and FasL, which potentiate the effect of paracrine and autocrine IFN-gamma and TNF-alpha release.

Apoptosis↗
PubMed2004

Reactivation of resolved hepatitis B virus infection after allogeneic haematopoietic stem cell transplantation.

Hepatitis B virus (HBV) reactivation after allogeneic haematopoietic stem cell transplantation (allo-HSCT) is well known in HBsAg-positive carriers but has only occasionally been reported in patients with resolved HBV infection. We investigated six allo-HSCT recipients with pretransplant anti-HBs and anti-HBc antibodies for serologic markers of HBV infection and for the presence of HBV-DNA in serum. Reverse seroconversion, that is, reappearance of HBsAg after a gradual loss of anti-HBs, but no severe liver damage was observed in three patients at 14, 22 and 12 months after HSCT, respectively. There was an increase in HBV-DNA concentration prior to reverse seroconversion. One patient was repeatedly HBV-DNA positive (10(2)-10(3) copies/ml) without reverse seroconversion. Sequencing of the HBsAg and precore region derived from the four HBV-DNA-positive patients showed no relevant mutations. In conclusion, this study demonstrated a high risk (50%) of reverse seroconversion in allo-HSCT recipients with resolved HBV infection. A highly sensitive HBV-DNA assay (TaqMan-PCR) allowed early identification of the individual patients at risk.

Adolescent↗
PubMed2003

Hematopoietic cell transplantation from related and unrelated donors after minimal conditioning as a curative treatment modality for severe paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disorder caused by a somatic mutation of the X-linked phosphatidylinositol glycan class A gene. Allogeneic hematopoietic cell transplantation (HCT) after high-dose conditioning is the only curative treatment; however, it is associated with high treatment-related mortality. Here, we report on allogeneic HCT for PNH after minimal conditioning. Seven adult patients with high-risk PNH underwent peripheral blood HCT from HLA-A-, -B-, -C-, -DRB1-, and -DQB1-matched related (n = 2) and unrelated (n = 5) donors. Conditioning included fludarabine 30 mg/m(2)/d on days -4 to -2 and 2 Gy of total body irradiation on day 0. After HCT, patients were given immunosuppressive therapy with oral cyclosporine starting on day -3 and mycophenolate mofetil starting on day 0. All 7 patients attained durable engraftment. After 28 days, a median of 77% (range, 53%-96%) T-cell donor chimerism was found in bone marrow and peripheral blood. T-cell chimerism increased to 91% (range, 76%-100%) on day +180 and to 100% in all surviving patients after 12 months. All 7 patients attained complete remissions of their disease. Four patients are alive 13 to 38 months after HCT. Three patients died of treatment-related mortality, 1 because of complications after acute pancreatitis and multiorgan failure, 1 because of infection related to chronic graft-versus-host disease (GVHD), and 1 because of bleeding after liver biopsy for late subacute/chronic GVHD. Allogeneic HCT from related and unrelated donors after minimal conditioning is a new and potentially curative option for patients with advanced PNH.

Adolescent↗
PubMed2002

Acute pneumatosis cystoides intestinalis following allogeneic transplantation -- the surgeon's dilemma.

Pneumatosis cystoides intestinalis (PCI) is still a poorly understood phenomenon, currently considered to result from primary mucosal insult from varying causes. We report a case of severe PCI in a patient with chronic GVHD after bone marrow transplantation (BMT) performed to treat secondary AML. Post BMT, the patient suffered acute intestinal and cutaneous GVHD, eventually developing intestinal and biopsy-proven cutaneous chronic GVHD, which necessitated continuous steroid therapy. Chronic pancreatitis associated with GVHD was diagnosed by explorative surgery in February 2000 on the basis of increasing epigastric discomfort, tumour marker (CA 125) increase and the CT finding of a suspicious mass in the pancreas. Readmission occurred in April 2000 for rapid onset of inferior abdominal pain with distinct peritoneal signs. Relaparotomy, deemed necessary on the grounds of both clinical and radiological findings, revealed marked PCI of the ascending and transverse colon and attached mesentery in an otherwise intact gastrointestinal tract. Post-operative reconvalescence was uneventful, with no clinical or radiological recurrence of PCI in the following 10 months. In the context of a review of the relevant literature, this case report illustrates the complex underlying pathophysiology, and difficulty in making a differential diagnosis and treating PCI.

Acute Disease↗
PubMed2002

The impact of antithymocyte globulin on short-term toxicity after allogeneic stem cell transplantation.

Antithymocyte globulin (ATG) is commonly used in allogeneic haematopoietic stem cell transplantation (HSCT). Little information is available, however, as to the optimal protocol for use and the side-effects occurring if ATG is administered in high daily doses (10-30 mg/kg). We report our experience with ATG Fresenius (ATG-F) in conditioning for allogeneic HSCT. During a period of 3 days, 47 patients received doses between 10 and 30 mg/kg either over 4 h preceded by 1-1.5 mg/kg prednisolone 30 min before the start of ATG-F (protocol A) or alternatively, over 12 h with 3-4 mg/kg prednisolone being administered before and 6 h after start of ATG (protocol B). During treatment with ATG-F, the side-effects observed included inflammation, disseminated intravascular coagulation, hyperdynamic circulation and renal dysfunction. Although these complications caused substantial morbidity, they were reversible within a few days. Side-effects were significantly more severe in patients treated according to protocol A than in those treated according to protocol B. As prolonged infusion of ATG-F does not reduce T cell clearance due to the long half-life of ATG-F, and since less cytokine release during conditioning might have beneficial long-term effects, we recommend administering ATG-F over 12 h preceded by high-dose steroid treatment.

Adolescent↗