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Biomedical subjects

G Heil

Publications and source records attributed to G Heil.

At least 73 records · Page 4Linked to original sources
PubMed1991

Ultrastructural demonstration of peroxidase expression in acute unclassified leukemias: correlation to immunophenotype and treatment outcome.

The lineage affinity of 57 cases of acute unclassified leukemias (AUL) was reevaluated by ultrastructural analysis of peroxidase expression (POEM) in combination with immunophenotyping and analysis of immunoglobulin gene configuration. Twenty-three cases of myeloid and three cases of megakaryocytic differentiation were identified by detection of ultrastructural myeloperoxidase (UMPO) and platelet peroxidase (UPPO). No significant correlation was noted between myeloid marker expression and POEM positivity, whereas presence of CD 19 or CD 24 antigen significantly correlated with POEM negativity (P = .001 and .023, respectively). Ig gene rearrangements including oligoclonal patterns were also recorded in 8 of 14 UMPO+ patients tested. Fourteen UMPO+ patients responded poorly to an ALL/AUL chemotherapy regimen with a low complete remission (CR) rate of 29% and a short median remission duration (MRD) of 5 months. The POEM- patients proved very heterogenous with respect to immunophenotype and Ig gene rearrangement. Seventeen of 21 patients tested had Ig gene rearrangements, including oligoclonal patterns. Combined data suggest that a proportion of these cases probably derive from a very immature lymphoid progenitor cell, particularly because 15 POEM- AUL patients showed a response to ALL/AUL chemotherapy comparable to that observed in patients with definitive acute lymphoblastic leukemia (ALL) (CR rate 80%, MRD 20 months). Thus, ultrastructural analysis of peroxidase expression can provide decisive prognostic information in AUL patients.

Acute Disease↗
PubMed1990

Treatment of relapsed acute lymphocytic leukemia in adults.

Thirty-three patients with ALL/AUL in first relapse were treated with an induction of prednisone, vindesine, daunorubicin, Erwinia asparaginase, i.t. MTX (phase I), high-dose cytarabine, and etoposide (phase II). Twenty-one (64%) achieved a complete remission, one a partial remission. Side effects of induction-phase I were predominantly hematological with subsequent infections and gastrointestinal toxicity. In phase II some patients had additional cutaneous, ocular, and hepatic toxicity. The treatment efficiently induced remissions with tolerable toxicity in relapsed ALL. The disease-free survival, however, needs to be improved.

Adolescent↗
PubMed1990

Aggressive polychemotherapy for acute myelofibrosis.

Acute myelofibrosis is a rare and still ill-defined disease. Based on morphological observation, immunophenotyping and ultrastructural analysis, we support the assumption that acute myelofibrosis is a malignant disorder mainly of the megakaryocytic lineage and is closely related to acute megakaryocytic/blastic leukaemia. Consequently, the 11 patients reported here were treated with aggressive polychemotherapy with combinations including daunorubicin and cytosine arabinoside and 6-thioguanin or VP16-213. 4 complete remissions, 2 partial remissions and 1 minor response were observed. Duration of aplasia was not significantly prolonged. These findings indicate that the use of aggressive polychemotherapy is feasible in acute myelofibrosis and results in a significant number of remissions.

Acute Disease↗
PubMed1990

[The detection of the pathogenicity of Listeria using permanent cell lines as an alternative for animal studies].

Culture filtrates of 38 strains of Listeria (L.) monocytogenes and of 4 strains of L. ivanovii were all cytotoxic for the vero cell line. Culture filtrates from 35 strains of L. innocua, 12 strains of L. seeligeri, 5 strains of L. welshimeri and 4 strains of L. grayi showed no cytotoxicity for the continuous cell line vero. The use of continuous cell lines permits to distinguish between pathogenic and non-pathogenic Listeria strains and seems to be a suitable method to replace the mouse pathogenicity test or the fertilized hen's eggs test.

Animal Testing Alternatives↗
PubMed1990

Treatment of refractory acute lymphoblastic leukemia in adults with high dose cytosine arabinoside and mitoxantrone (HAM).

In a clinical phase II study the combination of high dose cytosine arabinoside and mitoxantrone (HAM) was applied to 24 patients with refractory acute lymphoblastic leukemia (ALL). All patients had received a standardized first line treatment and were considered refractory against conventional chemotherapy as defined by nonresponse to induction treatment (n = 8), nonresponse to an alternative salvage regimen at first relapse (n = 9), second and third relapses (n = 5) and relapse after bone marrow transplantation (n = 2). Therapy consisted of HD-araC 3 g/m2 q 12 hr days 1-4 and mitoxantrone 10 mg/m2/d days 2-5 or 2-6. Twelve of the 24 patients (50%) achieved a complete remission (CR), one patient had a partial remission, and five patients were nonresponders. Five patients died in aplasia due to infections, one additional patient succumbed to HD-araC related CNS toxicity. Nonhematologic side effects consisted predominantly in infection, nausea and vomiting, mucositis and diarrhea. Recovery of blood counts occurred at a median of 28 days from the onset of treatment; the median time to CR was 33 days. Three of the 12 responders underwent subsequent bone marrow transplantations and one is alive disease free at 40+ months. The median remission duration for the remaining nine patients is 3.5 months, with one case in ongoing CCR at 36+ months; the median survival time is 5 months. Considering the selection of a highly unfavorable group of patients, these data demonstrate a significant antileukemic activity of HAM in refractory ALL and support its application as consolidation treatment during first line ALL therapy.

Adolescent↗
PubMed1989

Use of bioassay methods to evaluate mutagenicity of ambient air collected near a municipal waste combustor.

An ambient air sampling study was conducted around a municipal waste combustor; a primary goal was to develop procedures and methods to evaluate the emissions of organic mutagens resulting from incomplete combustion of municipal waste. The products of incomplete combustion from incineration include complex mixtures of organics, particularly polycyclic aromatic compounds, which are present after atmospheric dilution and cooling in emissions as semi-volatile or particle bound organic compounds. Combustion emissions are generally recognized as a potential cancer risk since they contain many carcinogenic and mutagenic polycyclic aromatic hydrocarbons. Analyzing such a complex mixture for the presence of even a few selected chemicals is difficult and provides risk information on only a fraction of the chemicals present. Bioassay methods, however, may be directly applied to evaluate the mutagenic and potential carcinogenic activity of the complex organics from combustion emissions. The Salmonella (Ames) assay was used to determine the mutagenicity associated with particles from ambient air collected near a municipal waste combustor. Dose-response data was generated, and mutagenicity concentrations were calculated to demonstrate the utility of bioassay in assessing the potential impact of emissions from municipal waste combustion. This phase of study quantified mutagenicity concentrations in ambient air but did not detect organic mutagens that could be attributed to incinerator emissions.

Air Pollutants, Occupational↗
PubMed1989

[The occurrence of Clostridium difficile in fecal samples of dogs and cats].

Fecal samples of 150 dogs and 175 cats originating from different veterinary practices were investigated for assessing the occurrence of Clostridium (Cl.) difficile by using a selective medium for cultural isolation. From dogs without enteric symptoms 7 (9.3%) of 75 samples were positive for Cl. difficile, with 2 strains being cytotoxic for bovine embryonic lung fibroblast cells, which could be neutralized by Cl. difficile-antitoxin. In samples of 75 dogs with enteric symptoms Cl. difficile could be isolated in 2 cases (2.7%). In cats 9 (9%) of 100 fecal samples deriving from animals without enteric symptoms contained Cl. difficile, while in 75 cats with enteric symptoms, the isolation rate was 6.7% (5 strains). Of either group only 1 Cl. difficile-strain showed cytotoxicity for tissue culture. The results of this study allow to conclude, that in contrast to the significance for man Cl. difficile is neither for dogs nor for cats an important enteric agent. However these pets can harbour and shed strains of Cl. difficile, even cytotoxigenic ones, in faeces. In view of these findings the possibility of occasional human infections by household dogs or cats needs attention and further investigation.

Animals↗
PubMed1989

Phenotypic and genotypic heterogeneity in infant acute leukemia. I. Acute lymphoblastic leukemia.

We have studied the immunophenotypic and genotypic features in 35 infants aged less than 1 year with acute lymphoblastic leukemia (ALL) or acute undifferentiated leukemia (AUL). A CD10 (common ALL antigen)-negative, CD19-positive pre-pre-B ALL phenotype was observed in 24 infants. Seventeen of them had blast cells coexpressing myeloid-associated markers such as CD15A (VIM-D5, MZ17) and/or VIM-2, but neither myeloperoxidase nor platelet peroxidase was detected in five of these cases analyzed by electron microscopy. Five patients showed a typical common ALL, five a pre-B ALL phenotype, and one infant was unclassifiable by surface-marker and morphologic analysis. Cytogenetic data, available in 21 of these patients, revealed chromosomal abnormalities involving 11q23 in 10 infants with a CD10-negative pre-pre-B ALL. Immunoglobulin (Ig) and T cell receptor (TCR) gamma, beta and delta gene analysis of 31 infants showed Ig heavy-chain gene rearrangement in all but one patient with evidence for clonal evolution in six and kappa-light-chain rearrangement in three infants. TCR beta-chain and TCR gamma-chain rearrangement occurred in six and five patients respectively, while TCR delta-chain rearrangement was identified in 15 patients. Our data indicate that ALL in infancy may present with heterogeneous immunophenotypic and genotypic features. The high frequency of coexpression of B-lineage and myeloid surface markers as well as of chromosomal rearrangement involving 11q23 suggests that the clonogenic cell of infant ALL may relate to a multipotent progenitor cell in most cases.

Antibodies, Monoclonal↗
PubMed1988

Induction of myeloperoxidase in five cases of acute unclassified leukaemia.

For further analysis of their lineage affinity the differentiation capacity of five cases of acute unclassified leukaemias were studied in vitro using 5 nM 12-O-tetradecanoyl-phorbol-13-acetate as an inducing agent. After 4 d in vitro a co-expression of both myeloid and early B-lymphoid or myeloid and early T-lymphoid antigens on the same population of cells was found. While ultrastructural analysis of the blasts prior to culture revealed the morphology of undifferentiated blasts without any specific endogenous peroxidase activity, the cultured blasts displayed monoblastic features and myeloperoxidase activity after 4 d in vitro. Since this type of peroxidase is highly specific for the myelomonocytic lineage the data indicate myelomonocytoid differentiation of all five cases studied. The co-expression of lymphoid as well as myeloid antigens and myeloperoxidase by the same blasts after culture could be indicative of bilineage differentiation capacity characterizing the original blasts as bipotential progenitor cells.

Acute Disease↗
PubMed1988

[Induction and intensive combined therapy of acute myeloid leukemia in adults].

In a prospective multicenter study the efficacy and toxicity of an induction therapy with daunorubicin, cytosine-arabinoside and VP 16-213, followed by an intensified consolidation with high-dose cytosine-arabinoside and daunorubicin, is evaluated in adult patients with acute myelogenous leukemia. The upper age limit for inclusion in the study was 50 years. Within the first two years of this study 91 patients were enrolled. In 84 patients who have finished the remission induction therapy the rate of complete remissions is 67%. The median survival time of all patients is 22 months and the probability of survival is 46% after 24 months. So far 34 patients in complete remission have been given one or two courses of the intensified consolidation therapy with high-dose cytosine-arabinoside and daunorubicin. The probability of relapse-free survival in these patients is 46% after 22 months and the median remission duration is 20 months.

Adolescent↗
PubMed1988

[Intensive combined therapy for high-risk ALL patients].

In the risk-adapted multicenter trial (02/84) for adult ALL the effectiveness of a consolidation therapy consisting of VM26 and Ara-C for high-risk patients was tested. Out of a total of 442 patients in the study, 79.2% achieved a complete remission. For the 182 high-risk patients the median remission duration is 17 months and the probability of being in continuous complete remission (CCR) is 34%. Improved results were found for elderly ALL patients between 35 and 65 years of age, whose median remission duration and CCR rate are 19 months and 40% respectively, compared to 15 months and 26% in the former study 01/81. The consolidation therapy has apparently also benefited patients with the immunological subtype c-ALL, for whom the CCR rate at 3 years is 53% in comparison to the previous value of 34%.

Adolescent↗