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Biomedical subjects

D Hoelzer

Publications and source records attributed to D Hoelzer.

At least 127 records · Page 7Linked to original sources
PubMed1998

[Growth factors in oncology: effectiveness and prospects].

The hematopoietic growth factors G-CSF and GM-CSF stimulate the proliferation and differentiation of myeloid precursor cells leading to an accelerated granulocytic regeneration after chemotherapy and to a shortened duration of "febrile neutropenia". Criteria for the clinical application should be defined which take the advantage for the comfort of the patient and the economic aspect into account. The American Society for Clinical Oncology has published recommendations for the treatment with hematopoietic colony-stimulating factors, which are useful with the exception of the proposal to reduce the chemotherapy dose with the goal to save expensive CSF treatment. The use of CSF for treatment of afebrile and uncomplicated neutropenia should be reduced.

Adult↗
PubMed1998

Correction of respiratory burst activity in X-linked chronic granulomatous cells to therapeutically relevant levels after gene transfer into bone marrow CD34+ cells.

Chronic granulomatous disease (CGD) is a disorder of the lymphohematopoietic system, whereby phagocytes of affected patients are unable to kill microorganisms. CGD is caused by a functional defect in the phagocytic nicotinamide adenine dinucleotide phosphatase (NADPH) oxidase (phox) enzyme complex, leading to a lack of microbicidal metabolites. As a therapeutic approach toward the predominant X-linked form of CGD, we have developed a bicistronic retroviral vector containing the coding sequences of gp91-phox and a cytoplasmically truncated version of the human low-affinity receptor for nerve growth factor (deltaLNGFR). Full reconstitution of superoxide-generating activity was achieved with this vector in a gp91-phox-deficient cell line. Using an optimized gene transfer protocol, up to 85% of the CD34+ cells obtained from the bone marrow of X-CGD patients were transduced. CD15+ cells differentiated in vitro from transduced X-CGD CD34+ cells showed correction of NADPH oxidase activity to 45-52% of normal levels whereas deltaLNGFR expression was found in 40-67% of the CD15+ cells. Moreover, immunoblots prepared from extracts of transduced CD15+ cells revealed gp91-phox protein levels similar to those found in neutrophils derived from normal CD34+ cells. Taking into consideration that superoxide production in only 5 to 10% of wild-type neutrophils is sufficient to protect X-CGD heterozygotes from serious infections, the results achieved in this study shows that for X-CGD patients a curative approach based on the genetic modification of hematopoietic stem/progenitor cells is feasible.

Antigens, CD34↗
PubMed1998

Piperacillin/tazobactam versus cefepime as initial empirical antimicrobial therapy in febrile neutropenic patients: a prospective randomized pilot study.

The objective of the presented prospective, randomized study was to compare the efficacy of empirical antimicrobial monotherapy with piperacillin/tazobactam (PIP/TAZ) to cefepime (CEFP) for treatment of infections in neutropenic patients. From a total of 102 febrile episodes 100 were evaluable. The most frequent microorganisms were gram-negative, documented in 22% vs. 24% of the febrile episodes (gram-positives 18% vs. 16%, fungi 2% vs. 4%). The response rate was similar with 22/51 (43%) of episodes treated with PIP/TAZ vs. 19/49 (39%) with CEFP. Of the different infection types classified at the end of the febrile episodes, patients with fever of unknown origin (FUO) and primary bacteremias showed the best initial responses with 25/44 (57%) and 11/22 (50%). Lower initial response rates were found in pneumonias with totally 3/13 (23%) and other clinically documented infections with 2/21 (10%), without any difference between both groups. Gram positive infections showed a higher response with PIP/TAZ than with CEFP (4/9 vs. 0/8), gram negative responded less frequently (3/11 vs. 7/13). The median time until persistent defervescence was equal in both groups (2.5 vs. 2 days), likewise the response rates after the different steps of therapy modifications (change to imipenem or ceftazidim, or addition of gentamycin, vancomycin or amphotericin B). Totally, 96% of febrile episodes responded in both therapy arms. Overall, we found no significant differences in efficacy between the two therapeutic regimens. In conclusion, PIP/TAZ as well as CEFP might be a sufficient initial therapy for febrile neutropenia, but further randomized trials with larger patient numbers are necessary.

Anti-Infective Agents↗
PubMed1998

Mechanism of gamma sigma T-cell-mediated inhibition of stem cell differentiation in vitro: possible relevance for myelosuppression in HIV-infected individuals.

We investigated whether gamma delta T cells contribute to the suppression of myelopoiesis in HIV infection. Freshly isolated gamma delta T cells from HIV seropositive patients suppressed CFU-GM growth in vitro. Preactivation of gamma delta T cells with IL-2 and/or IL-15 further reduced the number of CFU-GM. Natural killer cells and to a lower extent CD4+ and CD8+ cells also inhibited CFU-GM growth. In contrast to gamma delta T cells, this effect was not dependent on IL-15 or IL-2 preactivation. Moreover, no enhanced inhibitory effect of CD56+ and CD4+ cells was observed in HIV+ subjects compared to HIV- donors. The myelosuppressive effect of supernatants of gamma delta T cells could be inhibited by antibodies against IFN-gamma or TNF-alpha. Accordingly, we found increased numbers of TNF-alpha or IFN-gamma-secreting CD8+ gamma delta T cells in HIV+ patients. We conclude that the increased fraction of activated gamma delta T cells producing myelosuppressive cytokines might contribute to the dyshematopoiesis frequently observed in HIV-infected individuals.

Cell Differentiation↗
PubMed1998

Differential expression of bcl-2 and susceptibility to programmed cell death in lymphocytes of HIV-1-infected individuals.

The bcl-2 protooncogene encodes an inner mitochondrial membrane protein that blocks programmed cell death. There is now increasing evidence that regulation of bcl-2 expression is a determinant of life or death in normal lymphocytes. In this study, we examined bcl-2 expression in lymphocytes from human immunodeficiency virus type 1 (HIV-1)-infected and healthy subjects by flow cytometry. bcl-2 expression was detected in more than 97% of peripheral blood lymphocytes in both healthy and HIV-infected individuals. It was consistently observed that CD4+ lymphocytes from HIV-1-infected individuals with less than 200 CD4+ cells/microliter expressed significantly less bcl-2 than healthy controls. In contrast, bcl-2 expression in CD8+ lymphocytes of these patients was significantly enhanced. No significant alteration of bcl-2 expression was found when lymphocytes of healthy individuals were polyclonally activated in the presence of various regulatory cytokines. Cells undergoing apoptosis showed significantly lower bcl-2 expression than viable cells. Staining of apoptotic cells revealed that lymphocytes from HIV-1-infected subjects were characterized by an increased susceptibility to programmed cell death which was not restricted to a particular lymphocyte subset. Despite significantly different bcl-2 expression in CD4+ and CD8+ lymphocytes of HIV-1-infected individuals with less than 200 CD4+ cells/microliter, no difference could be observed concerning their susceptibility to undergo apoptosis. Therefore, we conclude that sensitivity or resistance to in vitro induction of apoptosis does not directly correlate with bcl-2 expression.

Adult↗
PubMed1998

L-tryptophan-related eosinophilia-myalgia syndrome possibly associated with a chronic B-lymphocytic leukemia.

A female patient presenting with B-CLL and coincident eosinophilia-myalgia syndrome (EMS) after ingestion of L-tryptophan is described. The manifestations of EMS disappeared completely during treatment with cyclophosphamide/prednisone. and there was an intermittent clinical remission of CLL with absence of the monoclonal B-cell population. A few years later, the B-CLL relapsed, but without sign and symptoms of EMS. Whereas other eosinophilic syndromes such as eosinophilic fasciitis, panniculitis, or cellulitis Wells have been found to occur in relation to malignant underlying diseases, only a single patient with malignant fibrous histiocytoma following EMS has been described. There are no reports about an increased occurrence of B-CLL or other non-Hodgkin's lymphomas combined with or following EMS or related to L-tryptophan itself. The variant types of eosinophilic syndromes occurring due to malignant disorders, the differentiation from EMS, and the possible association between B-CLL and L-tryptophan-related EMS are discussed.

Adult↗
PubMed1998

Growth factors in the treatment of acute lymphoblastic leukemia.

The safety of G-CSF and GM-CSF in adult and pediatric patients with ALL has been well established. In addition, prophylactic administration of G-CSF was shown to significantly accelerate neutrophil recovery in most clinical trials. This was associated with a substantially reduced incidence and duration of febrile neutropenia and of severe infections in selected high risk patients receiving multiple treatment cycles, whereas the clinical benefit appears to be negligible in patients at low risk of infectious complications. There is currently insufficient evidence to support the use of GM-CSF as an adjunct to treatment for ALL outside of clinical trials. Apart from patient characteristics and type of CSF, it has become evident that scheduling of growth factor administration in relation to the type of chemotherapy, and use of different study end points influence the clinical efficacy of HGF administration. Although no studies have so far shown that use of growth factors is associated with reduced mortality, higher complete remission rates or superior survival, improvements in other clinical endpoints, e.g. infection rate, duration of i.v. antibiotics, and length of hospital stays were frequently perceived as clinically important and felt to contribute substantially to the patient's quality of life. It will become increasingly important to select those patients likely to benefit from growth factor support and to identify additional predictive criteria. Scheduling of CSFs, e.g. early versus delayed and prophylactic versus interventional administration, the type of growth factor used and the duration of administration need to be optimized in the context of specific treatment protocols. Although myeloid growth factors presently can not be expected to have a major impact on overall treatment outcome in patients with ALL, they facilitate important incremental improvement; in supportive care when appropriately applied. As the remaining open questions are resolved, clinical benefits may be achieved consistently and with a favorable cost benefit ratio.

Cost-Benefit Analysis↗
PubMed1998

Prospective randomized study to compare imipenem 1.5 grams per day vs. 3.0 grams per day in infections of granulocytopenic patients.

The objective of this presented prospective randomized study was to compare the efficacy of empirical antimicrobial monotherapy with imipenem 3 x 0.5 g per day to 3 x 1.0 g per day for treatment of infections in neutropenic patients. A total of 192/220 febrile episodes were evaluable for clinical efficacy. The overall response rate was 53/93 (57%) vs. 57/99 (58%). Of the different infection types, fever of unknown origin (FUO) showed the best response, with defervescence in 29/41 (71%) and 36/42 (86%) cases, respectively (not significant). Unfavourable results were found in pneumonias [5/20 (25%) vs. 4/23 (17%)]. The median time until persistent defervescence was equal in both groups (2 days), likewise the median duration of imipenem therapy in responders (7 days). The most frequent micro-organisms were Gram-negative, documented in 22% of the febrile episodes in the lower dosage group vs. 17% of all episodes in the patients with imipenem 3.0 g per day (Gram-positives 17% vs. 14%, fungal 5% vs. 8%). In the lower dosage group, fever with abdominal symptoms occurred less frequently (8% vs. 15%), and significantly more patients tolerated imipenem without any side-effects (95.8% vs. 79.4%), especially regarding severe nausea/vomiting (2.1% vs. 11.8%). Of the initial non-responders, 35/40 (88%) vs. 41/42 (98%) were cured after therapy modification. There was no significant difference in the use of further antibiotics such as aminoglycosides, glycopeptides, ceftazidime or amphotericin B, except a marginally higher use of metronidazole in patients with imipenem 3.0 g per day (3% vs. 10%). Overall, we found no significant differences in efficacy between the two study groups, but more frequent side-effects with imipenem 3.0 g per day.

Adolescent↗
PubMed1998

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

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.

Drug Resistance, Neoplasm↗
PubMed1998

Graft-versus-leukemia effects in T lineage and B lineage acute lymphoblastic leukemia.

T and B lineage ALL cells express different levels of HLA-class II antigens, which may serve as targets for graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL). The object of this study was to determine whether GVL effects after HLA-identical sibling bone marrow transplantation differed in T and B lineage ALL. We studied 1132 patients with ALL of T lineage (n = 416) or of B lineage (cALLa+) (n = 716) transplanted in first (n = 605) or second (n = 527) remission with bone marrow from an HLA-identical sibling donor, between 1982 and 1992, and reported to the IBMTR by 165 teams. Cox proportional hazards regression models were used to determine the relative risk (RR) of relapse in patients with acute (grades II-IV) or chronic GVHD vs patients without GVHD. Acute and chronic GVHD were considered as time-dependent covariates. Patients transplanted in first and second remission were analyzed separately. GVHD decreased relapse risks to a similar extent in T and B lineage ALL. For first remission transplants, relative risks of relapse for patients with vs those without GVHD was 0.34 for T lineage ALL and 0.44 for B lineage ALL. Corresponding relative risks in second remission transplants were 0.54 and 0.61. This study confirms earlier findings of an antileukemia effect of GVHD in ALL. This effect was similar in T lineage and B lineage ALL, despite probable differences in HLA-class II antigen expression.

Adolescent↗
PubMed1998

Recombinant human granulocyte and granulocyte-macrophage colony-stimulating factor (G-CSF and GM-CSF) administered following cytotoxic chemotherapy have a similar ability to mobilize peripheral blood stem cells.

The availability of hematopoietic growth factors has greatly facilitated the mobilization and collection of peripheral blood stem cells (PBSC). It was the aim of this double-blind study to compare the PBSC-mobilizing efficacy of recombinant human G-CSF and GM-CSF when administered post-chemotherapy. Twenty-six patients with relapsed Hodgkin's disease were included in the study. Their median age was 31 years (range, 22-59) and 14 patients were males and 12 were females. Patients were pretreated with a median of eight cycles of cytotoxic chemotherapy, while 18 patients had undergone extended field irradiation. The patients received dexamethasone 24 mg days 1-7, melphalan 30 mg/m2 day 3, BCNU 60 mg/m2 day 3, etoposide 75 mg/m2 days 4-7, Ara-C 100 mg/m2 twice daily days 4-7 (Dexa-BEAM). Twelve patients were randomized to receive 5/microg/kg/day G-CSF and 14 patients to receive 5 microg/kg/day GM-CSF, both administered subcutaneously starting on day 1 after the end of Dexa-BEAM. Primary endpoints of the study were the number of CD34+ cells harvested per kg body weight on the occasion of six consecutive leukaphereses and the time needed for hematological reconstitution following autografting. Twenty-one patients completed PBSC collection, and six patients of the G-CSF group and nine of the GM-CSF group were autografted. No difference was observed with respect to the median yield of CFU-GM and CD34+ cells: 32.5 x 10(4)/kg vs 31.3 x 10(4)/kg CFU-GM, and 7.6 x 10(6)/kg vs 5.6 x 10(6)/kg CD34+ cells, for G-CSF and GM-CSF, respectively (U test, P= 0.837 and 0.696). High-dose chemotherapy consisted of cyclophosphamide 1.7 g/m2 days 1-4, BCNU 150 mg/m2 days 1-4, etoposide 400 mg/m2 days 1-4. All patients transplanted with more than 5 x 10(6) CD34+ cells/kg had a rapid platelet recovery (20 x 10(9)/l) between 6 and 11 days and neutrophil recovery (0.5 x 10(9)/1) between 9 and 16 days, while patients transplanted with less than 5 x 10(6)/kg had a delayed reconstitution, regardless of the kind of growth factor used for PBSC mobilization. In conclusion, our data indicate that in patients with Hodgkin's disease G-CSF and GM-CSF given after salvage chemotherapy appear to be not different in their ability to mobilize PBSC resulting in a similar time needed for hematological reconstitution when autografted following high-dose therapy.

Adult↗
PubMed1998

High rate of chromosome abnormalities detected by fluorescence in situ hybridization using BCR and ABL probes in adult acute lymphoblastic leukemia.

The value of dual-color fluorescence in situ hybridization (FISH) with BCR and ABL probes for the detection of the Philadelphia (Ph) translocation and of other alterations involving ABL and/or BCR was evaluated in adult acute lymphoblastic leukemia (ALL). One hundred and four patients were studied prospectively using interphase nuclei FISH, chromosome analysis (CA), and PCR assays for the chimeric BRC/ABL transcript. FISH detected a Ph translocation in 24 cases (23.1%), as was confirmed by CA and/or PCR. FISH revealed a false positive diagnosis of a Ph translocation in four cases (5% false positive rate). Among 54 cases with combined FISH, CA and PCR assays, FISH failed to establish a correct diagnosis in 3.7%, PCR in 5.6%, and CA in 7.4%. The combination of two screening methods led to discrepant results in 9.3% (FISH + PCR), 11.1% (FISH + CA), or 13% (CA + PCR) of the cases. In seven of 80 (8.8%) Ph-negative patients, gain of BCR and/or ABL was identified. Overall, FISH detected alterations of the BCR and/or ABL genes with an incidence of 29.8% of the current study. Due to the possibility of false positive diagnosis of a Ph translocation using dual-color FISH the combination with chromosome and/or RT-PCR analyses is recommended in adult ALL patients.

Adolescent↗
PubMed1998

Increase in Vdelta1+ gammadelta T cells in the peripheral blood and bone marrow as a selective feature of HIV-1 but not other virus infections.

Dysregulation of T-cell receptor (TCR) alphabeta bearing lymphocytes and an increase in Vdelta1+ gammadelta T cells are typical features of HIV-1 infection. However, the role of gammadelta T cells remains unclear. Therefore, peripheral blood mononuclear cells (PBMC) of 103 HIV-1-infected patients were investigated with respect to expression of Vdelta1. These results were compared to the Vdelta1 expression of bone marrow mononuclear cells (BMMC). In contrast to healthy controls, Vdelta1+ cells dominated among both PBMC and BMMC in HIV-1-infected patients. Analysis of the coexpression of CD25, CD8, HLA-DR and CD45RO revealed a high prevalence of Vdelta1/CD45RO and Vdelta1/HLA-DR double-positive PBMC only in HIV-1-infected patients but not in healthy donors. Furthermore, analysis of the gammadelta TCR repertoire in patients infected with hepatitis B virus, hepatitis C virus, herpes simplex virus (HSV)-1 and HSV-2 showed that the selective enhancement of Vdelta1+ cells was restricted to HIV infection and not observed in other virus diseases. Our data provide further support for the involvement of gammadelta T cells in immunosuppression and progression of HIV infection.

Adult↗
PubMed1998

Detection of karyotypic aberrations in acute myeloblastic leukaemia: a prospective comparison between PCR/FISH and standard cytogenetics in 140 patients with de novo AML.

In 140 patients with de novo acute myeloid leukaemia (AML) standard cytogenetics were compared with RT-PCR for the detection of t(8;21), t(15;17) and inv(16) and fluorescence in situ hybridization (FISH) for numerical aberrations of chromosomes 7, 8, X and Y. RT-PCR detected 18 cases with t(8;21), 12 with t(15;17) and seven with inv(16). In two cases with t(8;21), two with t(15;17) and four with inv(16) these aberrations had not been detected by standard cytogenetics. There were no false negative PCR results. In 12 patients with these chromosomal changes, standard cytogenetics revealed additional chromosomal aberrations. In 16 patients sole numerical aberrations of the chromosomes 7, 8, X or Y were found by FISH. In these patients the sensitivity of FISH and standard cytogenetics was comparable. In 87 patients no aberrations could be found by PCR and FISH whereas in 24 of these patients standard cytogenetics revealed an abnormal karyotype. These data recommend the combination of standard cytogenetics and molecular techniques to improve the sensitivity for the detection of genetic lesions in AML. Once chromosomal markers have been identified by combined analysis these markers could be used to monitor residual disease during/after chemotherapy, by RT-PCR and/or FISH.

Adult↗
PubMed1998

HFE codon 63/282 (H63D/C282Y) dimorphism in German patients with genetic hemochromatosis.

Genetic hemochromatosis (GH) is closely associated with genes of the major histocompatibility complex (MHC) on chromosome 6. Recently, a candidate gene for GH, with structural similarities to MHC class I genes, designated HLA-H and presently named HFE, has been cloned. The HFE gene is localized telomeric to the MHC and several reports have indicated that the HFE gene is mutated in GH patients. In the present study we have analyzed the relationship of HFE gene variants and disease manifestation in GH patients and family members. Fifty-seven patients with GH, 73 family members and 153 healthy blood donors were studied for the amino acid dimorphism at codon 63 (His63Asp=H63D) and codon 282 (Cys282Tyr= C282Y) of the HFE gene. The codon 63 and 282 dimorphism were defined by PCR amplification of genomic DNA samples and restriction enzyme digestion using RsaI/SnaBI for C282Y and BclI/MboI for H63D. Ferritin, transferrin serum levels and total iron-binding capacity were determined prior to therapeutic intervention. The Tyr-282 substitution occurred in 53 (93%) of patients compared with 8 (5.2%) of controls (OR=169, P<0.0001). Fifty-one (90%) patients were Tyr-282 homozygous. In contrast, the Asp-63 substitution was present in 5 (8.8%) of the patients compared with 34 (22%) of controls (OR=0.39, P=NS) with none of the patients being homozygous. In Tyr-282 homozygous GH patients serum ferritin levels, transferrin saturation, liver iron and liver iron index were elevated significantly compared to Tyr-282-negative patients, whereas no difference was observed between Tyr/Cys-282 heterozygous and Tyr-282-negative patients.

Aspartic Acid↗
PubMed1997

A randomized, double-blind, placebo-controlled, phase III study of filgrastim in remission induction and consolidation therapy for adults with de novo acute myeloid leukemia. The International Acute Myeloid Leukemia Study Group.

The safety and efficacy of filgrastim as an adjunct to acute myeloid leukemia (AML) induction and consolidation therapy was assessed in this prospective double-blind, randomized, placebo-controlled, multicenter trial. A total of 521 consecutive de novo AML patients aged 16 or more years were randomized to receive filgrastim (5 microg/kg/d subcutaneously) or placebo after standard induction as well as consolidation chemotherapy. Blinded study drug was given from 24 hours after chemotherapy until the absolute neutrophil count was >/=1.0 x 10(9)/L for 3 consecutive days. The overall complete remission rate was 68%. After a median follow-up of 24 months (range 5 to 40) the median disease-free survival was 10 months (95% confidence interval [CI], 8.7 to 10.8) and the median overall survival was 13 months (95%CI, 12.2 to 14.6). These did not differ between treatment groups. Patients receiving filgrastim experienced neutrophil recovery 5 days earlier after induction 1 than those receiving placebo (P < .0001). This was accompanied by reductions in the duration of fever (7 v 8.5 days; P = .009), parenteral antibiotic use (15 v 18.5 days; P = .0001), and hospitalization (20 v 25 days; P = .0001). Similar reductions were seen after induction 2 and the consolidation courses. There was a significant reduction in the number of patients requiring systemic antifungal therapy in the filgrastim group during induction treatment (34% v 43%; P = .04). In conclusion, filgrastim is safe in that it had no negative impact on the prognosis of the AML patients. In addition, it effectively reduced the duration of neutropenia, leading to significant clinical benefits by reducing the duration of fever; requirement for parenteral anti-infectives, specifically amphotericin B; and the duration of hospitalization.

Adolescent↗