Search PubMed⌕ Search

Biomedical subjects

H Zankl

Publications and source records attributed to H Zankl.

At least 37 records · Page 2Linked to original sources
PubMed1991

Characterization of marker chromosomes in Namalva cells by chromosomal in situ suppression (CISS) hybridization and R-banding.

Chromosomal in situ suppression (CISS) hybridization was used to investigate the distribution of material of chromosomes 1 and 5 present in marker chromosomes of Namalva cells. The Namalva cell line, established from a Burkitt's lymphoma, exhibits a highly variable female karyotype with a large number of marker chromosomes. Libraries from sorted human chromosomes 1 and 5 were used to delineate material of these chromosomes present in the Namalva karyotype. We used the DAB/peroxidase reaction and reflection contrast microscopy for detection of biotinylated hybrid molecules. Identification of chromosomes was achieved by fluorescent R-banding after CISS hybridization, which allowed the assignment of hybridized regions to the particular marker chromosomes. After CISS hybridization with a chromosome I library, the normal chromosome I was labelled as well as a large marker MI and the long arm of marker M3. Using a chromosome 5 library it could be shown that the distal part of the long arm of one chromosome 5 was translocated to marker M2. The normal chromosome 5 was completely labelled. The present investigation demonstrates the advantage of combining CISS hybridization and banding for the identification of complex, rearranged tumor karyotypes.

Burkitt Lymphoma↗
PubMed1991

Adriamycin-induced sister chromatid exchange and chromosomal aberrations in Down's syndrome lymphocytes.

Blood samples from six Down's syndrome (DS) and six age- and sex-matched controls were cultured for 72 h in the presence of BrdUrd. Lymphocytes were then analysed at their second mitosis for sister chromatid exchange (SCE) and at their first mitosis for chromosome aberrations. Treatment with adriamycin (30 and 60 ng) showed a significant increase in frequency of SCE and chromosome aberrations in DS lymphocytes compared to normal lymphocytes at initiation of culture. Cells treated with adriamycin (ADR) for the last 24 h also showed a significant increase in SCE in DS lymphocytes compared to normal lymphocytes. A significant increase in chromatid-type aberrations was also recorded in DS lymphocytes after both treatments cultured for the last 24 h.

Cell Cycle↗
PubMed1991

Mechanism of action of the urinary bladder carcinogen N-nitrosobutyl-3-carboxypropylamine.

The carcinogenic action of N-nitrosodibutylamine in the urinary bladder is related to omega-oxidation of a butyl chain. N-Nitrosobutyl-4-hydroxybutylamine and its proximate metabolite N-nitrosobutyl-3-carboxypropylamine (NBCPA) selectively induce urinary bladder tumours in different animal species. The mechanism by which NBCPA exert its carcinogenic action is not known. We found a small but significant dealkylation of NBCPA with microsomes from rat liver or pig urinary bladder, which could be inhibited by SKF 525A. NBCPA was not mutagenic to Salmonella typhimurium (with or without external metabolizing systems from rat liver or pig urinary bladder) and did not induce DNA strand breaks in tumour cell lines (with or without external activation) or primary cells (rat hepatocytes, pig urinary bladder epithelia). Significant induction of sister chromatid exchange and micronuclei, however, was observed in human tumour cells. N-Nitrosoureas that generate the same electrophiles as NBCPA after alpha- or via beta-oxidation (N-butyl-N-nitrosourea, N-3-carboxypropyl-N-nitrosourea and N-2-oxopropyl-N-nitrosourea) induced single-strand breaks in Namalva cells, the oxopropyl compound being more potent than the butyl or carboxypropyl compounds. Our data suggest that NBCPA is activated via alpha-oxidation in the urinary bladder, even though the activation rate in vitro is so low that a positive response is not detectable by classical short-term tests. Provided that beta-oxidation to a highly genotoxic agent proceeds at an adequate rate, it might also be a relevant activation pathway.

Animals↗
PubMed1990

Use of a centromere-specific DNA probe (p82H) in nonisotopic in situ hybridization for classification of micronuclei.

The DNA probe p82H was used to visualize centromeric DNA in micronuclei (MN) of human cells. Slides prepared from cultures treated by the aneugen (causing aneuploidy) colcemid showed significantly more MN with centromeric signals than those treated by the clastogen (causing chromosome breakage) bleomycin. These results indicate that in situ hybridization with the alphoid p82H DNA probe is a suitable method with which to distinguish between MN containing whole chromosomes and acentric fragments, and hence allows one to discriminate between the clastogenic and aneugenic effects in MN formation.

Aneuploidy↗
PubMed1990

Platelet-tumor cell interaction.

Several reports have appeared with regard to the potential role of platelets in tumor cells metastasis. Our in vitro studies with colon tumor cells in normals and in patients give some evidence against platelet aggregation as the determinant factor in tumor cell invasion and metastasis. Dimethylhydrazine induced colon tumors in Wistar rats demonstrate characteristic features of tumor cell dissociation in the invasion line and changes in intercellular adhesion.

Actin Cytoskeleton↗
PubMed1989

Investigations on organ-specific metabolism and genotoxic effects of the urinary bladder carcinogen N-nitrosobutyl-3-carboxypropylamine (BCPN) and its analogs N-nitrosodibutylamine (NDBA) and N-nitrosobutyl-4-hydroxybutylamine (4-OH-NDBA).

N-Nitrosodibutylamine (NDBA) and its omega-oxidized metabolites N-nitrosobutyl-4-hydroxybutylamine (4-OH-NDBA) and N-nitrosobutyl-3-carboxypropylamine (BCPN) are potent urinary bladder carcinogens. To study putative organ specific activation of BCPN, its alpha-oxidation by liver and urinary bladder microsomal fractions was investigated in comparison to NDBA and 4-OH-NDBA. Additionally, induction of DNA single strand breaks (SSB) was monitored in hepatocytes and in a human lymphoblastoid cell line (Namalva) in the presence and absence of external metabolic activation, including N-nitroso-t-butyl-n-butylamine as a negative control. BCPN was alpha-hydroxylated and dealkylated at both alkyl chains in small rates (about 1 nmol x mg protein-1 x 60 min-1) by microsomes from rat liver and pig urinary bladder epithelium. NDBA and 4-OH-NDBA were dealkylated at similarly low rates by pig urinary bladder microsomes, in strong contrast to the high debutylation rates observed for rat liver microsomes. Correspondingly, SSB induction by NDBA and 4-OH-NDBA was observed in Namalva cells with NDBA and 4-OH-NDBA in the presence of PB-induced rat liver microsomes but not with urinary bladder microsomes or without external activation. BCPN did not induce DNA-damage in Namalva cells (with or without external activation) or in rat hepatocytes. Significant induction of sister chromatid exchanges (SCEs) and micronuclei, however, was observed in Namalva cells after incubation with NDBA and BCPN. Our data suggest activation of BCPN via alpha-oxidation in the urinary bladder, even though activation rate in-vitro is so low that a positive response is not detectable by several short-term tests.

Animals↗
PubMed1989

Increased mutagenicity of N-nitrosodiethanolamine in human lymphocyte cultures after activation by alcohol dehydrogenase.

The effect of alcohol dehydrogenase (ADH/NAD) from yeast and horse liver was tested on the induction of chromosomal mutations and sister chromatid exchanges (SCE) by N-nitrosodiethanolamine (NDELA) in human lymphocyte cultures. BrdUrd (27 micrograms) was added 24 h after starting the cultures to allow visualisation of SCE. ADH/NAD and NDELA were added 24 h later in different concentrations. No significantly higher level of numerical or structural chromosome aberrations was observed. However, the SCE frequency per cell was significantly increased by adding NAD (31.25 mumol and 62.5 mumol). The exclusive addition of 220 units ADH from yeast as well as 1.8 units ADH from horse liver also raised the number of SCE highly significantly. The combination of NAD and ADH was more effective than each substances alone in the yeast but not in the horse liver system. NDELA in a range of 12.5-62.5 mumol, given to cultures with ADH/NAD from yeast, additionally increased the SCE frequencies in a dose-dependent way. Similar results were found in cultures containing ADH/NAD from horse liver and 6.25-31.25 mumol NDELA, but the total numbers of SCE were distinctly higher. These results indicate that NDELA is strongly activated by ADH from yeast but even more by ADH from horse liver.

Alcohol Dehydrogenase↗
PubMed1988

Tetraploidy and Y chromosome loss in acute mixed-lineage leukemia.

An unusual case of acute leukemia with mixed phenotype was followed up from diagnosis to death for about 12 months. The first cytogenetic examination revealed about 80% of the bone marrow cells in the diploid and 20% in the tetraploid range. After two courses of induction therapy, complete remission was achieved within 2 months. At this time the tetraploid cells were reduced to 3%, but 50% of the mitoses showed a Y chromosome loss, while the other mitoses had a diploid karyotype. Early intensification therapy was given 6 weeks later with slow recovery of blood counts. After four months a sharp decrease of the number of Y-missing mitoses was observed, while the marrow remained in full remission. Two months later a relapse occurred and the patient died. At this time the -Y clone had dropped to 2% and the tetraploid clone was totally absent. We conclude from these findings that the diploid clone was the most malignant one, whereas the -Y cells were probably not directly involved in the leukemic process.

Chromosome Banding↗
PubMed1988

Cytogenetic effects of N-nitrosodiethanolamine (NDELA) and NDELA-monoacetate in human lymphocytes.

The mutagenicity of N-nitrosodiethanolamine (NDELA) and NDELA monoacetate was tested in vitro on lymphocytes of two healthy probands by determining the frequencies of chromosome aberrations, micronuclei and sister chromatid exchanges (SCE). A dose-dependent increase was found in all three test systems for NDELA as well as its monoacetate. The SCE test proved to be most sensitive for the genotoxic effect of NDELA because the differences to the control cultures had already become significant at 250-625 mumol/culture (26.6-65.4 mM). However, NDELA monoacetate showed a higher reactivity in the micronuclei and chromosome aberration test: significantly increased values were found even at 12.5 mumol (1.3 mM), whereas in the SCE test the differences became significant at the 25-mumol (2.7 mM) level. NDELA caused significantly increased rates of micronuclei and chromosome aberrations only at the highest test levels (625-1250 mumol; 65.4-127.6 mM). The results indicate important differences in the genotoxic effects of the two compounds, which might be explained by different lipophilicity and/or special activation processes.

Carcinogens↗
PubMed1986

Acute myelomonocytic leukemia (M4) with eosinophilia: problems concerning chromosome 16 abnormality.

A case of acute myelomonocytic leukemia is reported which was hematologically classified as M4 (FAB), because the patient had a high count of immature eosinophils with typical histochemical features in the bone marrow. An abnormal chromosome #16 was found besides a trisomy 22 or a monosomy 18 in part of the cultured bone marrow cells and unstimulated blood cells but not in directly prepared bone marrow. The structural aberration of chromosomes #16, which was demonstrated best by CBG-banding, was more likely due to a partial deletion of the long arm than to an inversion. The difficulties involved in correct cytogenetic diagnosis of such cases are discussed.

Bone Marrow↗
PubMed1985

SCE frequency and lymphocyte proliferation in a Down's syndrome mosaic developing an acute lymphoblastic leukemia.

Sister chromatid exchange and cell proliferation time were examined by differential chromatid staining in a Down's syndrome, mosaic case suffering from acute lymphoblastic leukemia. The SCE frequency in stimulated blood lymphocytes had already increased before treatment was started. The therapy was correlated with a further SCE increase in the trisomic cells but not in the normal ones. The trisomic cells showed a shortened cell cycle time in the remission phase, as well as during therapy. In both cell lines, a very similar slow down in cell proliferation was observed after treatment, as indicated by a high number of mitoses from the first and second mitotic cycle. The results indicate that the trisomic cells are more sensitive to the mutagenic effect of the antileukemic treatment than are normal cells.

Cell Cycle↗
PubMed1985

Long term cultivation of Namalva cells for interferon production: stable cytogenetic markers for identification of cells in spite of drastic chromosomal variation.

Namalva cells were propagated continuously over a period of up to 18 months. During this period the chromosomal status of the cell populations were investigated cytogenetically. The ability of the cells to produce interferons after induction with Sendai virus was monitored. In contrast to the drastic chromosomal variation observed, interferon production was remarkably stable. Comparison of the various cytogenetic data revealed the presence of marker chromosomes and chromosomal constellations which were excluded from the drift. Some of these are useful for unequivocal identification of Namalva cells during long term cultivation.

Cells, Cultured↗
PubMed1985

Clonal analysis of diversity in the BSp73 rat tumor.

By implantation of BSp73 ascites cells in a subcutaneous site and subsequent subcutaneous passage of either the local tumor node or metastatic lung tissue, variants were obtained which differed with respect to morphology and to metastatic capacity. The highly metastasizing variant ASML showed spherical morphology in culture, while the nonmetastatic variant AS showed adhesion and spreading. Upon cloning it was observed that colonies with fully expressed morphotypes were readily obtained from solid tissue of both variants. Parental ascites as well as the tumor line derived from the primary solid tumor gave rise to stable expression of either morphotype only after prolonged culturing. Mixing of established clones did not result in an interclonal adaptation of growth rates in vivo. Further characterization of variants AS and ASML revealed marked differences in the outer cell surface. Adhesion of AS cells onto plastic was found to be mediated by fibronectin, laminin and 4 out of 5 collagen types. ASML cells showed adhesion only with collagen type III at higher concentrations. Cytogenetic analysis revealed that the adaptation of BSp73 cells to ascitic growth ultimately led to an increase in chromosome numbers, and this was conserved in ASML cells (modal number 63, range 49-74). AS cells on the other hand showed a modal number of 47 (range 45-49). The chromosome count distribution was rather narrow in ascites cells in vivo, but it was very broad in clones derived thereof, indicating that diversity was obtained in culture rather than in vivo. The data are compatible with the assumption that the nonmetastatic variant was not preexisting in BSp73 ascites but represents a stable phenotype which infrequently arises in a particular microenvironment by chromosome loss from a hyperdiploid parental population.

Animals↗
PubMed1983

Sister chromatid exchange and lymphocyte proliferation in a Down syndrome mosaic.

The number of SCE was compared in the normal and trisomic cell lines of a trisomy 21 mosaic case. It was found that in the trisomic cells the SCE-frequency was twice as high as in the normal cells. The mitoses with high numbers of SCE (above 10) were increased 4-5 fold. Differential chromatid staining also allowed us to determine the mitotic cycle of the mitoses. The percentage of mitoses from the fourth or a later mitotic cycle was significantly higher in the trisomic cell line than in the normal one. From this result, it can be concluded that the cell cycle time was distinctly shortened in the cells with trisomy 21.

Cells, Cultured↗
PubMed1982

Cocultivation studies with cells of patients bearing fragile X chromosomes.

Fourteen cocultivation studies were carried out with cells of our patients with fragile X, one obligate and two possible female heterozygotes, two female controls, and a rabbit. In all cocultivations the number of fragile X chromosomes was sharply reduced in the patient cells. The strongest effect was causes by the animal cells. A distinct difference between the two controls in the reducing ability was observed. No such difference was found between the obligate and possible heterozygotes on the one hand and the controls on the other. To test the influence of the residual serum in the mixed blood cultures, the serum of a patient's blood sample was replaced by the serum of a control. The frequency of fragile X chromosomes was not decreased by this procedure. Therefore a soluble factor is supposed to exist which is produced by normal or heterozygote cells in culture and which reduces the expression of fragile sites in patient cells.

Animals↗
PubMed1982

Cytogenetic studies on the nucleolar organizer region [NOR] activity in meningioma cells with normal and hypodiploid karyotypes.

The association pattern and NOR silver staining of the acrocentric chromosomes was studied in normal and hypodiploid cell lines of four meningioma patients. In three cases the hypodiploid cells showed a more increased association frequency or NOR silver staining or both than the normal ones, indicating a compensatory mechanism between the NORs. Chromosomes #14 seemed to be more frequently involved in this phenomenon than other acrocentric chromosomes. From the silver staining results it was concluded that in meningioma cells, chromosomes #22 which bear active as well as inactive NORs were missing. The compensation between the NORs was probably only activated if an active NOR was lost.

Cell Line↗