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Biomedical subjects

W Hiddemann

Publications and source records attributed to W Hiddemann.

At least 379 records · Page 21Linked to original sources
PubMed1989

Detection and separation of intracellular 1-beta-D-arabinofuranosylcytosine-5-triphosphate by ion-pair high-performance liquid chromatography.

An ion-pair high-performance liquid chromatographic method, using a reversed-phase C18 column, was developed to provide an isocratic, sensitive, fast and reproducible separation of intracellular 1-beta-D-arabinofuranosylcytosine-5-triphosphate and its measurement at a low limit of 5 pmol by ultraviolet absorbance at 280 nm with a coefficient of variation lower than 10%. A rapid separation is achieved by using a backflush procedure at 16 min and the retention time is 14 min.

Arabinofuranosylcytosine Triphosphate↗
PubMed1989

Mitoxantrone and high-dose cytarabine as salvage therapy for refractory non-Hodgkin's lymphoma.

Mitoxantrone (Novantrone, NO) and high-dose cytarabine (Ara-C, AC) have each been shown in monotherapy trials to be active in non-Hodgkin's lymphoma (NHL). In the current study, a combination of the two drugs (NOAC) was administered to 31 patients with advanced NHL refractory to modern sequential chemotherapy regimens. Ara-C was administered at 3 g/m2 as a 3 hour infusion every 12 hours on day 1 (2 doses) and mitoxantrone at 10 mg/m2/day on days 2 and 3. Of the 18 patients with high-grade malignant NHL, six have attained a complete remission (CR) and two, a partial remission (PR). One CR and 5 PRs were achieved among the other 13 patients with intermediate or low-grade NHL. The median time to relapse (TTR) of patients achieving CR was 7 months with a range from 4 to 17 months. Myelosuppression with subsequent infections was the major toxicity of this regimen. The median duration of severe neutropenia (less than 0.5/nl) was 9 days with a range of 0 to 27 days and the median duration of severe thrombocytopenia (less than 20/nl), 5 days with a range of 0 to 35 days. Infectious complications during cytopenia was seen in 45.3% of the courses administered and fever of unidentified origin was seen in 42.3%. About 63% of the patients were hospitalized for intravenous antibiotic or antimycotic treatment. Other side effects were mild and included nausea, stomatitis, and transient tachycardia of greater than 100/min. Thus, this regimen was active in refractory NHL with poor prognosis, and the toxic side effects were not excessive. Evaluation of the activity of this regimen at higher dose levels of Ara-C is warranted.

Adolescent↗
PubMed1989

Flow cytometric DNA analysis of bone tumors.

Flow cytometric DNA analysis was performed in a total of 203 bone tumors, benign and malignant. In more than 80% of cases the material studied was paraffin-embedded tumor tissue, mainly from the archives of the Bone Tumor Registry of Westphalia in Münster. Compared with ethanol-fixed fresh tumor samples, the variation coefficient in DNA histograms of the stored material was increased by a factor of 1.2-1.5, which means that resolution was decreased and that, in many cases, accurate cell cycle analysis was not feasible. However, the results of cell cycle analysis in bone tumors, even if performed on optimally fixed specimens, have to be evaluated with caution and full reference to the corresponding histological slides, since these histograms are apt to show various superpositions from the inflammatory infiltrate. The assessment of DNA ploidy is unimpaired if, in agreement with most researchers today, deviations smaller than +/- 10% from the diploid standard are still defined as DNA diploid, peridiploid, or pseudodiploid. The coefficient of variation should be kept as low as possible. If it is between 10% and 15%, the near-diploid stemlines with DNA indices of 0.9 or 1.1 may be hard to delineate. On account of the particularly marked regressive changes, the resolution of DNA histograms was most strongly impaired in chondromatous tumors, whereas it was mostly excellent in highly cellular viable tumor tissue, such as that from Ewing's sarcoma or osteoblastoma. On the whole, there was a distinct correlation between DNA ploidy and the biological behavior of bone tumors (Table 8). The highest rates of DNA aneuploidy were found in highly malignant OSs (18/21) and FSs (14/16), thus reflecting their poor prognosis. Of six juxtacortical OSs, three well-differentiated parosteal OSs and two periosteal OSs were DNA diploid, whereas one highly malignant surface OS and five highly malignant extraskeletal OSs, all DNA aneuploid, corresponded fully to the medullary OSs. Judging by preliminary results, adjuvant preoperative chemotherapy (COSS 80/82: Bösing et al. 1987) may reduce the rate of DNA aneuploidy and, consequently, of stem cell heterogeneity in general. A selective destruction of those stemlines that respond particularly to chemotherapy appears probable. In contrast to their high malignancy, Ewing's sarcomas showed an unexpectedly low proportion of DNA aneuploid stemlines (14/24). The comparatively favorable prognosis of MFH of bone is reflected in a lower rate of aneuploidies (2/10), which is also rather low (probably too low) when compared to our own data from soft tissue MFH (9/19).(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Neoplasms↗
PubMed1989

Accidental overdose of mitoxantrone in three patients.

Mitoxantrone is a new effective antineoplastic agent with activity against a wide range of tumors. Compared with the anthracycline drugs doxo- and daunorubicin, it exhibits a clearly lower toxicity and, most importantly, a reduced cardiotoxicity. The analysis of the side-effects recorded after accidental overdosage of the drug gives additional insight into its tolerability. Here we describe our observations in three patients who inadvertently received 100 mg m-2 (two pts) and 183 mg m-2 (one pt) as single slow bolus injections. The main side-effects were moderate nausea and vomiting, shaking chills, and profound but reversible neutro- and thrombocytopenia. There was no immediate cardiac toxicity. One patient with extensive previous daunomycin exposure developed congestive heart failure after 4 months. Two patients were not evaluable for late cardiac complications because of early death due to tumor progression.

Adult↗
PubMed1989

What's new in malignant tumors in acquired immunodeficiency disorders?

An increased incidence of malignant tumors has long been recognized in patients with primary immune defects such as the X-linked lympho-proliferative syndrome or the Wiskott Aldrich syndrome and has recently become a major concern also in cases with acquired immunodeficiency. The latter may be induced by cytostatic therapy for cancer, extended immunosuppression following organ transplantation or HIV infection. The spectrum of secondary cancers is, however, different within these three groups of secondary immune defects with acute myeloid leukemia being the most common malignant disease after cytostatic therapy, with skin or lip cancer followed by non-Hodgkin's lymphoma as the prevalent malignancies after organ transplantations and Kaposi sarcoma and non-Hodgkin's lymphoma as the predominant cancers associated with HIV infection. The pathogenesis of Kaposi sarcoma and non-Hodgkin's lymphoma is possibly related to viral infections by cytomegalovirus and Epstein-Barr virus inducing an increased proliferation and possibly the coactivation of transforming genes of oncogenic potential. In AIDS patients Kaposi sarcoma is diagnosed in up to 40% of homosexual men while the other risk groups are less frequently involved. 4-10% of HIV infected patients experience non Hodgkin's lymphoma predominantly of B-cell type and intermediate or high grade malignancy with frequent extranodal manifestations. Other types of tumors occur at a substantially lower frequency and are not clearly related to the HIV infection. The overall survival of patients suffering from malignant tumors in the state of immunodeficiency is poor and the possibilities for therapeutic intervention are limited by the risk of accelerating the pre-existing suppression of defense mechanisms.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Age related randomized comparison of sequentially applied high-dose versus intermediate dose cytosine arabinoside in combination with mitoxantrone (S-HAM) in the treatment of relapsed and refractory acute myeloid leukemia: study design and preliminary results.

In a prospective randomized trial, the pending question was addressed whether Cytosine arabinoside (Ara-C) should be applied at high or intermediate dose to patients with relapsed or refractory acute myeloid leukemia. Based upon the previously established regimen of the sequential application of Ara-C and Mitoxantrone (S-HAM) patients below 60 years of age were randomized to receive Ara-C at either 3.0 g/m2 vs 1.0 g/m2 per dose while older patients were randomly assigned to either 1.0 g/m2 or 0.5 g/m2 Ara-C. At the present early stage 51 patients have entered the study and 37 are currently evaluable for response and toxicity. Complete remissions were achieved in 14 of 28 patients below 60 years of age and in 3 of 8 older cases. Predominant side effects consisted of nausea and vomiting, diarrhea and stomatitis. Further recruitment of patients and longer follow-up is required for the assessment of the various treatment arms.

Age Factors↗
PubMed1989

Acute myeloid leukemia: analysis of ras gene mutations and clonality defined by polymorphic X-linked loci.

In vitro DNA amplification and synthetic oligonucleotide hybridization was used to analyze 57 acute myelocytic leukemias (AML) for the presence of ras gene mutations. We demonstrated mutated alleles in 19% of primary AMLs (10/51) as well as in five of six secondary leukemias. Mutations occurred predominantly at N-ras codons 12, 13, or 61 (13 cases) and twice at Ki-ras codons 12 and 13. Ras gene mutations were preferentially associated with an M4 morphology according to the FAB (French-American-British) classification, but no particular correlation was observed with respect to clinical parameter (sex, age, course of disease) or immunophenotype and karyotype. Mutated ras alleles were absent in nine mutation-positive cases analyzed during remission. However, a more complex pattern emerged from the five patients analyzed in relapse exhibiting identical ras mutations in three cases, absence of a mutated allele in one patient, and acquisition of a N-ras mutation in yet another case, in which no mutation had been detected initially. Moreover, restriction fragment length polymorphisms (RFLP) of the X-chromosome genes hypoxanthine phosphoribosyl transferase (HPRT) and phosphoglycerate kinase (PGK) were studied in 19 of the AML patients. Nine cases (47%) were heterozygous for BglI or BamHI RFLPs at the PGK or HPRT loci, respectively, and therefore suitable for clonal analysis investigating X-chromosome inactivation. All of the patients exhibited a monoclonal leukemic cell population at presentation. In addition, five of seven cases studied in remission showed reemergence of a polyclonal pattern. However, two children exhibited persistence of monoclonal hematopoiesis despite complete clinical/hematological remission and a corresponding loss of a mutated ras allele in one of the patients. These data indicate the value of molecular genetic approaches for evaluation of the heterogeneous nature of remission and relapse in AML.

Adolescent↗
PubMed1988

[Clinical course and risk factors in patients with generalized mycoses].

A retrospective analysis of the clinical course of disseminated fungal infections in 32 patients revealed 25 cases of candidiasis, 5 patients with aspergillosis, and 2 with mixed fungal infections. All patients had undergone cytostatic therapy for malignant hematological diseases as the predisposing risk factor for fungal infection. 30 patients had severe granulocytopenia (less than 500/cmm). In addition, 30 patients had received broad spectrum antibiotics and 16 had been treated with corticosteroids. 17 of 32 patients were treated systemically with antimycotic drugs for proven fungal infection. No antimycotic agents were given to 15 patients because fungal infections were diagnosed only on post mortem examination. 19 patients succumbed to overwhelming disease, including 5 in spite of antimycotic therapy. Patients in whom systemic candidiasis was detected after recovery of granulocytopoeisis had a better prognosis than patients who developed systemic fungal infections during the period of ongoing severe granulocytopenia.

Adult↗
PubMed1988

High-dose cytosine arabinoside and mitoxantrone: preliminary results of a pilot study with sequential application (S-HAM) indicating a high antileukemic activity in refractory acute leukemias.

In an attempt to further improve on the encouraging results achieved by high-dose cytosine arabinoside (HD AraC) and mitoxantrone (HAM) in refractory acute leukemias, a timely modified sequential schedule of both drugs was developed (S-HAM) and applied to 13 patients with far advanced acute leukemias, 8 of whom had been treated with the original HAM protocol before. Based on the cell kinetic and pharmacokinetic rationale outlined by Capizzi et al., HD AraC 3 g/m2 was applied every 12 h on days 1 and 2 followed by mitoxantrone 10 mg/m2/day on days 3 and 4. After 3 days without therapy the identical sequence was repeated on days 8 and 9 (HD AraC) and 10 and 11 (mitoxantrone), respectively. Of the 13 patients 9 (69%) achieved a complete remission, 2 were resistant and 2 were early deaths. Six of the 8 patients with prior HAM treatment obtained a further complete remission with S-HAM. In 2 of these patients a longer remission was induced by S-HAM than by the preceding original HAM treatment. Although these data are preliminary and need confirmation on larger numbers of patients, they strongly suggest a high antileukemic activity of the S-HAM protocol which may even be superior to the previously used HAM regimen.

Adolescent↗
PubMed1988

Ambiguous phenotypes and genotypes in 16 children with acute leukemia as characterized by multiparameter analysis.

Ambiguous phenotypes and genotypes were observed in 16 children with acute leukemia. Surface marker, cytogenetic, molecular genetic, and DNA flow cytometric analyses as well as standard morphologic and cytochemical studies were used to divide the patients into three groups. The first group comprised five children with acute leukemia whose blast cells were morphologically lymphoid, while immunophenotyping disclosed simultaneous expression of early pre-B cell and myeloid features. Molecular genetic studies showed evidence of heavy-chain immunoglobulin (Ig) gene rearrangements in all patients. Cytogenetic data, available in three of these children, revealed t(4;11). In five of the 16 patients, morphologic and surface marker analyses indicated the coexistence of two separate cell populations, one with myeloid and the other with early pre-B cell features. Further evidence of B cell commitment in these patients was provided by demonstration of Ig heavy-chain gene rearrangements in all five patients. Surprisingly, one of the five patients showed oligoclonal Ig heavy-chain as well as monoclonal gene rearrangement for the beta chain of the T cell receptor (beta-TCR). The last group consisted of four cases with otherwise typical acute lymphoblastic leukemia (ALL), early pre-B cell phenotype, and coexpression of myeloid or T cell-associated antigens, and two children with unequivocal acute myeloid leukemia (AML) and coexpression of T cell antigens. Gene rearrangement of Ig heavy-chain could be demonstrated in five of six patients, additional Ig light-chain gene rearrangement in two children with ALL, and bigenotypic features (Ig heavy-chain and beta-TCR gene rearrangement) in one patient. In none of the 16 patients did flow cytometry disclose clonal abnormalities of leukemic cell DNA content. Based on these findings, we suggest that malignant transformation in the first and second group of patients took place at a stage ontogenetically close to the pluripotent stem cell, whereas ambiguous phenotypes in the third group resulted from aberrant gene expression or insufficient reagent specificity.

Acute Disease↗
PubMed1988

Human recombinant granulocyte macrophage colony stimulating factor (GM-CSF) treatment of patients with acute leukemias in aplasia and at high risk of early death.

In the first clinical study on GM-CSF in acute leukemias continuous infusion of the growth factor is given to patients in aplasia and at high risk of early death due to age over 65 years and/or intensive chemotherapy for resistance or relapse. Among 6 patients (4 AML, 2 ALL) receiving a total of 7 courses two died too early to contributing adequate data. Three patients and 4 courses showed earlier neutrophil recovery than related control groups and a fourth patient with secondary AML showed a neutrophil recovery time in the normal range, but much shorter than her platelet and reticulocyte recovery. No evidence was obtained so far for leukemic regrowth in these patients including blood and bone marrow cytology, monitoring of DNA aneuploidy by flow cytometry and clonogenic cells by colony assays. Thus, GM-CSF may be useful for rescue after intensive chemotherapy of AML and ALL and may not necessarily increase the risk of leukemia progression.

Aged↗
PubMed1987

Tumor heterogeneity in osteosarcoma as identified by flow cytometry.

Measurements of the cellular DNA content by flow cytometry were carried out in 25 untreated osteosarcomas to identify the frequency of DNA aneuploidies and heterogeneous DNA stemlines in relation to histopathology. Analyzing multiple specimens from each single tumor (2-16; median, 4), highly malignant osteosarcomas were found to express DNA aneuploidies in 18 of 21 cases (86%) with multiple aneuploid DNA stemlines in 10 cases (48%). In three paraosteal osteosarcomas, no DNA aneuploidy was detected and a significantly lower proportion of cells in S-phase was observed as compared to the highly malignant osteosarcomas (mean 8.6% vs. 18.8%; P less than 0.05). Like in the paraosteal osteosarcomas, no DNA aneuploidy and a low fraction of cells in S-phase was found in the predominant cell population of one of the very rare sclerosing small cell osteosarcomas, which also revealed a second DNA stemline with a DNA index of 2.0. These results demonstrate a high degree of DNA stemline heterogeneity in highly malignant osteosarcomas. The data emphasize the usefulness of DNA measurements for the characterization of bone tumors and indicate the possibility of discriminating highly malignant from low-grade osteosarcomas.

Aneuploidy↗
PubMed1987

Postinduction and preremission chemotherapy alternatives for adult AML: three multicenter studies of the AML Cooperative Group.

Major chemotherapeutic alternatives for AML have been implemented and compared in three multicenter studies, including a total of 877 adult patients of all ages. The results strongly suggest that myelosuppressive postinduction treatment is a prerequisite for the achievement of long-term remissions. In addition, it was possible to establish an important antileukemic effect of monthly maintenance chemotherapy. Initial results from an intensive two-course preremission therapy concept revealed good practicability and acceptable toxicity, as well as promising response and remission durations by this new approach.

Antineoplastic Combined Chemotherapy Protocols↗