Search PubMed⌕ Search

Biomedical subjects

N Schmitz

Publications and source records attributed to N Schmitz.

At least 19 recordsLinked to original sources
PubMed2006

Incidence and risk factors of central nervous system recurrence in aggressive lymphoma--a survey of 1693 patients treated in protocols of the German High-Grade Non-Hodgkin's Lymphoma Study Group (DSHNHL).

BACKGROUND: Central nervous system (CNS) relapse is a devastating and usually fatal complication of aggressive lymphoma. The extent of the disease, the proliferation rate and the sites of extranodal involvement have been discussed as risk factors. We analyzed the patients treated on protocols of the German High-Grade Non-Hodgkin's Lymphoma Study Group (DSHNHL) between 1990 and 2000, evaluated the rate and prognostic factors for CNS recurrence and developed a risk model trying to identify subsets of patients suitable for future prophylactic strategies. PATIENTS AND METHODS: From 1993 to 2000, 1399 patients [ 60 years irrespective of LDH] were randomized to receive six cycles of combination chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP)-21, CHOP-14 or six cycles of CHOP+etoposide (CHOEP)-21, CHOEP-14 in a 2x2 factorial study design in the NHL-B1/B2 studies. From 1990 to 1997, 312 patients<or=60 years with an elevated LDH were randomized to five cycles CHOEP+involved field (IF) radiotherapy or three cycles CHOEP followed by high-dose BCNU, etoposide, cytarabine and melphalan (BEAM) and autologous stem-cell transplantation (NHL-A study). RESULTS: A total number of 1711 patients were initially eligible for this study, of whom 18 patients had to be excluded due to primary CNS involvement. In the remaining 1693 assessable patients, 37 cases of relapse or progression to the CNS (2.2%) were observed. The protocol asked for an intrathecal (i.th.) prophylaxis in patients with lymphoblastic lymphoma only (n=17), but overall 71 patients (71 of 1693=4.2%) received prophylaxis by decision of the treating physicians. Multivariate Cox regression analysis identified increased LDH (P<0.001) and involvement of more than one extranodal site (P=0.002) as independent predictors of CNS recurrence in the NHL-B1/B2 study population. Treatment with etoposide also evolved as a prognostic factor because the risk of CNS failure was significantly reduced after CHOEP (P=0.017). Elderly patients presenting with both an elevated LDH and lymphoma involvement in liver, bladder or adrenals had an up to 15-fold risk of spread of the disease to the CNS. CONCLUSION: The incidence of CNS relapse in 1693 patients treated for aggressive lymphomas on DSHNHL protocols from 1990 to 2000 was low (2.2%), although CNS prophylaxis was administered to <5% of patients. Thus, a general prophylaxis for all patients is not warranted, the less so since the effectiveness of i.th. prophylaxis itself is judged controversially. Increased LDH and involvement of more than one extranodal site were confirmed as independent risk factors. A cumulative 20% incidence of CNS disease in certain prognostic subgroups of elderly patients may render these candidates for i.th. prophylaxis; however, this approach would imply a potential overtreatment of approximately 80% of these patients deemed at high risk.

Adolescent↗
PubMed2006

Successful autologous stem cell transplantation in a severely immunocompromised patient with relapsed AIDS-related B-cell lymphoma.

There is now evidence that the tolerability and response to systemic chemotherapy in HIV-infected patients with AIDS-related lymphoma (ARL) is significantly improved by highly active antiretroviral therapy. Here we report an severely immunocompromised AIDS patient with recurrent ARL who was successfully treated with autologous stem cell transplantation (ASCT). We also review the current literature of ASCT in HIV-infected patients.

Adult↗
PubMed2006

AML1 deletion in adult mice causes splenomegaly and lymphomas.

AML1 (RUNX1) encodes a DNA-binding subunit of the CBF transcription factor family and is required for the establishment of definitive hematopoiesis. AML1 is one of the most frequently mutated genes associated with human acute leukemia, suggesting that genetic alterations of the gene contribute to leukemogenesis. Here, we report the analysis of mice carrying conditional AML1 knockout alleles that were inactivated using the Cre/loxP system. AML1 was deleted in adult mice by inducing Cre activity to replicate AML1 deletions found in human MDS, familial platelet disorder and rare de novo human AML. At a latency of 2 months after induction, the thymus was reduced in size and frequently populated by immature double negative thymocytes, indicating defective T-lymphocyte maturation, resulting in lymphatic diseases with 50% penetrance, including atypical hyperplasia and thymic lymphoma. Metastatic lymphomas to the liver and the meninges were observed. Mice also developed splenomegaly with an expansion of the myeloid compartment. Increased Howell-Jolly body counts indicated splenic hypofunction. Thrombocytopenia occurred due to immaturity of mini-megakaryocytes in the bone marrow. Together with mild lymphocytopenia in the peripheral blood and increased fractions of immature cells in the bone marrow, AML1 deficient mice display features of a myelodysplastic syndrome, suggesting a preleukemic state.

Animals↗
PubMed2006

Allogeneic and autologous transplantation for haematological diseases, solid tumours and immune disorders: definitions and current practice in Europe.

The Accreditation Subcommittee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred since the first report was published in 1996. Haemopoietic stem cell transplantation today includes grafting with allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. The introduction of alternative therapies has challenged well-established indications such as imatinib for chronic myeloid leukaemia. An updated report with revised tables and operating definitions is presented here.

Europe↗
PubMed2005

Omega- and Omega+ production in central Pb + Pb collisions at 40 and 158A GeV.

Results are presented on Omega production in central Pb+Pb collisions at 40 and 158A GeV beam energy. For the first time in heavy ion reactions, rapidity distributions and total yields were measured for the sum Omega(-) + Omega(+) at 40A GeV and for Omega(-) and Omega(+) separately at 158A GeV. The yields are strongly underpredicted by the string-hadronic UrQMD model but agree better with predictions from hadron gas models.

Journal Article↗
PubMed2005

System-size dependence of strangeness production in nucleus-nucleus collisions at squareroot[sNN]=17.3 GeV.

Emission of pi+/-, K+/-, phi, and Lambda was measured in near-central C+C and Si+Si collisions at 158 AGeV beam energy. Together with earlier data for p+p, S+S, and Pb+Pb, the system-size dependence of relative strangeness production in nucleus-nucleus collisions is obtained. Its fast rise and the saturation observed at about 60 participating nucleons can be understood as the onset of the formation of coherent systems of increasing size.

Journal Article↗
PubMed2005

[Unilateral hyperlucent lung induced by a carcinoid tumor: comments on the differential diagnosis and mechanisms of hypoperfusion].

We report the case of a 35-year-old woman in whom a systematic thoracic x-ray led to the diagnosis of unilateral hyperlucent lung due to a carcinoid tumor obstructing the main left bronchus almost completely. Injected computed tomography permitted diagnosis of left lung hypoperfusion and visualization of the tumor. After enlarged inferior left lobar resection, normal perfusion was observed six months later on the isotopic lung perfusion scan. Other reported causes of unilateral hyperlucent lung are discussed as well as pathophysiological mechanisms of lung hypoperfusion and hypoxic vasoconstriction.

Adult↗
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

The role of allogeneic stem-cell transplantation in Hodgkin's disease.

The role of allogeneic stem cell transplantation is still controversial. Early results of allogeneic bone marrow transplantation after conventional conditioning indicated high transplant-related mortality (TRM) (> 50%) and disappointing survival (< 20%). The introduction of reduced-intensity conditioning (RIC) prior to transplantation has reduced TRM. Unfortunately graft-vs.-host disease, relapse rates and survival have not substantially changed. Modifications of allogeneic transplantation in patients with Hodgkin's disease should be restricted to prospective trials.

Disease-Free Survival↗
PubMed2004

Lambda and lambda production in central Pb-Pb collisions at 40, 80, and 158A GeV.

Production of Lambda and Antilambda hyperons was measured in central Pb-Pb collisions at 40, 80, and 158A GeV beam energy on a fixed target. Transverse mass spectra and rapidity distributions are given for all three energies. The Lambda/pi ratio at midrapidity and in full phase space shows a pronounced maximum between the highest BNL Alternating Gradient Synchrotron and 40A GeV CERN Super Proton Synchrotron energies, whereas the Lambda/pi ratio exhibits a monotonic increase.

Journal Article↗
PubMed2004

Evidence for an exotic S= -2, Q= -2 baryon resonance in proton-proton collisions at the CERN SPS.

Results of resonance searches in the Xi(-)pi(-), Xi(-)pi(+), Xi;(+)pi(-), and Xi;(+)pi(+) invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi(-)pi(-) baryon resonance with mass of 1.862+/-0.002 GeV/c(2) and width below the detector resolution of about 0.018 GeV/c(2). The significance is estimated to be above 4.2sigma. This state is a candidate for the hypothetical exotic Xi(--)(3/2) baryon with S=-2, I=3 / 2, and a quark content of (dsdsū). At the same mass, a peak is observed in the Xi(-)pi(+) spectrum which is a candidate for the Xi(0)(3/2) member of this isospin quartet with a quark content of (dsus[-]d). The corresponding antibaryon spectra also show enhancements at the same invariant mass.

Journal Article↗
PubMed2004

Reduced-intensity conditioning prior to allogeneic transplantation of hematopoietic stem cells: the need for T cells early after transplantation to induce a graft-versus-lymphoma effect.

In patients with poor-risk relapse of aggressive lymphoma, reduced-intensity conditioning followed by allogeneic PBSCT may have its limitations because of rapid regrowth of the tumor. We tried to address this problem by intermediate-intensity conditioning followed by allogeneic SCT. A total of 21 patients received fludarabine, busulfan and cyclophosphamide prior to allogeneic SCT. In the first 10 patients, GVHD prophylaxis by CD34+ selection of the grafts was employed (group I). The next 11 patients received nonmanipulated grafts and mycophenolat mofetil plus cyclosporinA (group II). In group I, no GVHD was observed. In contrast, patients in group II had a significant risk of acute GVHD (aGVHD) (six patients with grade II-IV acute GVHD). However, in group I, all surviving patients progressed within 9 months. In contrast, eight of nine surviving patients of group II remain in remission after a median observation time of 10.5 months (range 4-22 months). Survival differed significantly between the groups (P=0.004). Multivariate analysis identified intensive GVHD prophylaxis as important risk factor for survival. These results support the existence of a clinically relevant GVL effect in aggressive lymphoma. T-cell depletion (or CD34 selection) of grafts is not recommended in patients with poor-risk aggressive NHL.

Adolescent↗
PubMed2004

Lenograstim after autologous peripheral blood progenitor cell transplantation: results of a double-blind, randomized trial.

A phase III, randomized, double-blind, placebo-controlled, multi-center trial was conducted in order to compare the incidence of microbiologically defined infections occurring after high-dose chemotherapy (HDT) and ASCT in 98 patients given lenograstim (Granocyte) and 94 patients given placebo after transplantation. Hematopoietic recovery, the use of i.v. antibiotics, the numbers of red blood cell and platelet transfusions, the days spent in hospital, and the days on parenteral nutrition were also compared. The incidence of infections until neutrophil recovery was significantly less in patients who received lenograstim after HDT and ASCT as compared to patients who received placebo (66 of 98 vs 86 of 94 patients, P<0.001). Lenograstim also significantly reduced the use of i.v. antibiotics (P<0.001) and the median duration of i.v. antibiotic treatment (8 days vs 10 days, P=0.04), improved neutrophil recovery (absolute neutrophil count >0.5 x 10(9)/l: 11 days vs 15 days, P<0.001) and reduced the number of days spent in hospital (15 days vs 17 days, P<0.001). The administration of lenograstim after HDT and ASCT significantly reduces the incidence of microbiologically defined infections until neutrophil recovery. It also leads to less use of antibiotics and earlier discharge from hospital.

Adjuvants, Immunologic↗
PubMed2003

Gamma-irradiation of blood products following autologous stem cell transplantation: surveillance of the policy of 35 centers.

Blood products should be irradiated during allogeneic stem cell transplantation and before performing autologous stem cell harvest for prevention of acute transfusion-associated graft-versus-host disease (TA-GVHD). Usually, irradiation of all blood products is continued lifelong in the allogeneic setting. Up to now, no broadly accepted rules exist concerning autologous stem cell transplantation. We present here the results of an inquiry sent to 47 German transplantation centers regarding the transfusion policy following autologous stem cell transplantation. The results of 35 answering centers are included. Ten out of 35 centers offer irradiated blood products lifelong to their patients, mainly for the prevention of mistransfusion of non-irradiated blood components to allogeneic recipients. Twenty-two out of 35 centers administer irradiated blood products for a special time span after autologous stem cell transplantation. In most centers, this time span is from 3 to 6 months. Only few centers (4/35) expand this time span to 1-2 years after transplantation. A minority of centers (3/35) gave non-irradiated blood products to all of their patients or to patients not suffering from acute leukemia or after total body irradiation (TBI) containing preparative regimens. Most centers (19/35) deliver irradiated blood products irrespective of the conditioning regimen. Fifty-three percent of the centers decide to donate irradiated blood products not depending on immunological reconstitution. But in most centers some kind of hematological reconstitution is a major criterion for termination of irradiated blood products. Sixty-four percent of the centers made no difference in transfusion policy in regard to the underlying disease. No center experienced cases of proofed TA-GVHD. Guidelines should be worked out concerning transfusion policy after autologous stem cell transplantation.

Blood↗
PubMed2003

Reduced-intensity conditioning followed by allogeneic hematopoietic cell transplantation in myeloid diseases.

Within the past years, reduced or modified doses of chemotherapy or radiotherapy have been widely studied for conditioning before allogeneic hematopoietic cell transplantation in patients with myeloid leukemia not eligible for conventional transplantation. The main goal was to reduce the substantial treatment-related mortality in this patient population while preserving the potential curative graft-versus-leukemia effect. This review summarizes results of published trials using reduced-intensity conditioning (RIC) in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), chronic myeloid leukemia (CML), and myelofibrosis. In most of the published trials conditioning contained fludarabine (90-180 mg/m(2)) in combination with busulfan (4 x 10 mg/kg), melphalan (90-140 mg/m(2)), or 2-5 Gy total body irradiation (TBI). Peripheral blood hematopoietic stem cells from related or unrelated donors were used as graft source in most of the studies. Post-transplantation immunosuppression consisted of cyclosporine combined with methotrexate or mycophenolate mofetil. Although the majority of the patients were above the age of 50 years, early treatment-related mortality was rather low. Nevertheless, the rate of clinically significant graft-versus-host disease (GVHD) seemed to be comparable to conventional transplants in most of the protocols. The outcome differed between trials, but diagnosis and disease status pre-transplant significantly influenced outcome. In summary, this approach is feasible and provides access to the curative potential of allogeneic stem cell transplantation for patients with higher age or comorbidities. Since the majority of the reports included heterogeneous patient populations, mostly with a short follow-up, more and specifically randomized studies are needed to define the role of RIC before allogeneic hematopoietic cell transplantation.

Hematopoietic Stem Cell Transplantation↗
PubMed2003

Allogeneic stem cell transplantation after reduced-intensity conditioning in lymphoid malignancies.

Allogeneic stem cell transplantation (allo-SCT) is an effective therapeutic option for a wide range of hematological malignancies. The toxicity of the conditioning regimen and graft-versus-host disease (GVHD) occurring after the infusion of the graft remain the most important factors leading to high morbidity and mortality. Reduced-intensity conditioning regimens have recently been developed in an effort to reduce the toxicity associated with conventional allo-SCT while preserving the curative potential of the graft-versus-tumor (GVT) effect. Most patients with lymphoproliferative disorders are not ideal candidates for allo-SCT due to higher age at diagnosis, which together with the advanced stage of disease at the time of transplantation can lead to a high transplant-related mortality (TRM). Preliminary experience indicates that reduced-intensity allo-SCT is feasible in such patients. The immediate TRM is low in comparison with conventional procedures and overall results seem promising, thus indicating the existence of a GVT effect. Nevertheless, all series are still low in numbers and follow-up is too short to draw definitive conclusions. Acute and chronic GVHD remain a significant problem with incidences comparable to the conventional setting in some series. Thus, therapeutic strategies must be sought to decrease GVHD without abrogating the GVT effect.

Graft vs Host Disease↗