Michael Nüsse | Goethe-Universität Frankfurt am Main (original) (raw)

Books by Michael Nüsse

Meno con il sostegno della Deutsche Forschungsgemeinschaft. Gruppi selezionati di grandi bronzi r... more Meno con il sostegno della Deutsche Forschungsgemeinschaft. Gruppi selezionati di grandi bronzi romani dall'Italia settentrionale, rinvenuti a Brescia (Brixia), Cividate Camuno (Civitas Camunnorum) e Verona (Verona), vengono esaminati in maniera sistematica con l'apporto di studiosi dalle diverse competenze scientifi che e con l'impiego di metodi innovativi, che combinano indagini archeologiche, tecnologiche e archeometriche. L'analisi delle opere riguarda sia la documentazione dello stato di conservazione e la ricostruzione della tecnica di fabbricazione, sia l'inquadramento formale e iconografi co dei bronzi e l'interpretazione del loro signifi cato e della loro funzione alla luce degli specifi ci contesti di collocazione originaria. La somma dei risultati ha consentito una valutazione complessiva delle peculiarità tecniche e artistiche della statuaria romana in bronzo nei centri presi in considerazione, anche in raffronto alle testimonianze dell'Italia centrale e meridionale.

Papers by Michael Nüsse

Cell and tissue kinetics

Nocodazole, a temporary inhibitor of microtubule formation, has been used to partly synchronize E... more Nocodazole, a temporary inhibitor of microtubule formation, has been used to partly synchronize Ehrlich ascites tumour cells growing in suspension. The gradual entry of cells into mitosis and into the next cell cycle without division during drug treatment has been studied by flow cytometric determination of mitotic cells, analysing red and green fluorescence after low pH treatment and acridine orange staining. Determination of the mitotic index (MI) by this method has been combined with DNA distribution analysis to measure cell-cycle phase durations in asynchronous populations growing in the presence of the drug. With synchronized cells, it was shown that in the concentration range 0.4-4.0 micrograms/l, cells could only be arrested in mitosis for about 7 hr and at 0.04 microgram/ml, for about 5 hr. After these time intervals, the DNA content in nocodazole-blocked cells was found to be increased, and, in parallel, the ratio of red and green fluorescence was found to have changed, showing entry of cells into a next cell cycle without division (polyploidization). It was therefore only possible to partially synchronize an asynchronous population by nocodazole. However, a presynchronized population, e.g. selected G1 cells or metabolically blocked G1/S cells, were readily and without harmful effect resynchronized in M phase by a short treatment (0.4 microgram/ml, 3-4 hr) with nocodazole; after removal of the drug, cells divided and progressed in a highly synchronized fashion through the next cell cycle.

Molecular toxicology

For a possible detection of aneuploidy induction by chemicals and ionizing radiation, fluorescein... more For a possible detection of aneuploidy induction by chemicals and ionizing radiation, fluorescein-bound antikinetochore antibodies (CREST-scleroderma antibodies) were used to discriminate between micronuclei deriving from acentric fragments or from chromosome loss induced in Chinese hamster cells. The cells were treated with aphidicolin, adriamycin, Hoechst 33258, colcemid, the alkylating agent diethyl sulfate, and ionizing radiation. The frequency of micronucleated cells, the fraction of kinetochore-positive and -negative micronuclei per cell, and the fraction of kinetochore-positive micronuclei was measured using immunofluorescence staining of kinetochores in micronuclei. Of the micronuclei and fragmented nuclei induced by colcemid, 99% contained kinetochores, whereas ionizing radiation induced only 4% of kinetochore-positive micronuclei. The other drugs induced variable, in some cases also cell-cycle-dependent, fractions of kinetochore positive micronuclei. With this technique a discrimination between clastogenic effects and effects that occur at the level of spindle formation of the agent studied seems to be possible. Flow karyotyping was used to study the induction of stable homogeneous and numerical aberrations in diploid Chinese hamster cell clones that had survived a dose of 15 Gy gamma-radiation. All analyzed clones showed deviations in their flow karyotypes: the mean number was 9.2 deviations per clone, compared to 1.1 deviations per clone in unirradiated control clones.

Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for AIDS. Enter your ... more Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for AIDS. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your ...

International Journal of Radiation Biology

In this report, in situ hybridization with whole chromosome painting probes was used to paint rad... more In this report, in situ hybridization with whole chromosome painting probes was used to paint radiation-induced micronuclei (MN) in three lymphoblastoid cells lines to investigate the frequency of radiation-induced MN. The results obtained for four different chromosomes showed that there was a significant deviation of the numbers of signal-positive MN from that expected on the basis of DNA proportionality. Restriction of the analysis to three chromosomes showed that the deviations arose primarily from chromosome 7, which was underrepresented in the numbers of signal-positive MN in the group of chromosomes studied.

Carcinogenesis

Glucosinolates (GL) can inhibit, retard or reverse experimental multistage carcinogenesis. When b... more Glucosinolates (GL) can inhibit, retard or reverse experimental multistage carcinogenesis. When brassica plant tissue is broken, GLs are hydrolyzed by the endogenous enzyme myrosinase (Myr), releasing many products including isothiocyanates (ITC). Synthetic ITCs like sulforaphane exert chemopreventive effects against chemically induced tumors in animals, modulating enzymes required for carcinogens' activation/detoxification and/or the induction of cell-cycle arrest and apoptosis in tumor cell lines. To investigate the chemopreventive potential of ITCs while reproducing the circumstances of dietary contact with sulforaphane, we studied proliferation, apoptosis induction and p53, bcl-2 and bax protein expression in Jurkat T-leukemia cells by sulforaphane, the ITC generated in situ in a quantitative manner by Myr starting from glucoraphanin (GRA). Jurkat cells were treated with different doses of GRA-Myr mixture. Effects on cell growth or survival were evaluated by counting trypan blue-excluding cells. Cell-cycle progression, apoptosis and expression of p53, bax and bcl-2 proteins were analyzed by flow cytometry. Results were analyzed by two-sided Fisher's exact test. Sulforaphane, but not GRA, caused G 2 /M-phase arrest (P ϭ 0.028) and increase of apoptotic cell fraction (P Ͻ 0.0001) in a time-and dose-dependent manner. Necrosis was observed after prolonged exposure to elevated sulforaphane doses. Moreover, it markedly increased p53 and bax protein expression, and slightly affected bcl-2 expression. These findings indicate that sulforaphane but not the native GL GRA can exert both protective and toxic effects inhibiting leukemic cell growth. Sulforaphane therefore deserves study as a potential chemopreventive/ chemotherapeutic antileukemic agent.

Methods in Cell Biology, 1994

Methods in Cell Biology, 1990

Cytometry, 1999

The detection of DNA-incorporated bromodeoxyuridine (BrdUrd) in mammalian cells is a well-known a... more The detection of DNA-incorporated bromodeoxyuridine (BrdUrd) in mammalian cells is a well-known and important technique to study cell cycle. The use of TO-PRO-3 for detection of BrdUrd substitution of DNA by dual-laser flow cytometry has been investigated. Fluorescence enhancement of TO-PRO-3 in BrdUrd-labeled cells is registered in combination with the fluorescence emission of the intercalating dye propidium iodide (PI) as a total DNA stain to give bivariate DNA/BrdUrd histograms. By the low concentration of only 0.3 mircoM TO-PRO-3, BrdUrd detection is optimized, and undisturbed total DNA content by PI can be detected as well. TO-PRO-3 is excited by a red HeNe laser and PI by an argon ion laser. In order to understand the binding of TO-PRO-3, energy transfer from PI to TO-PRO-3 has been measured as well as the influence of an external DNA binding dye such as Hoechst 33258 with Adenine-Thymine (AT) binding specificity. Cell cycle studies of human SCL-2 keratinocytes and mouse 3T3 c...

Cytometry, 1995

The effects of the tear gas 2-chlorobenzylidene malonitrile (CS) on mammalian cell proliferation ... more The effects of the tear gas 2-chlorobenzylidene malonitrile (CS) on mammalian cell proliferation were studied in detail using bromodeoxyuridine/Hoechst flow cytometry. In synchronized (G0/G1-phase) Chinese hamster embryo (CHE) cells, exposure to CS (60 microM) caused a permanent arrest in the G0/G1 phase in 50% of the cells and a delayed G0/G1 phase exit. In asynchronously growing CHE cells, the CS-induced cell kinetic perturbations varied with the cell cycle stage during treatment. While G1-phase cells showed a delayed progression through S and G2/M phases, S-phase cells were mainly inhibited in the G2/M compartment of the first cell cycle. In contrast, CS-treated, asynchronous, amniotic fluid-derived, fibroblast-like (AFFL) cells exhibited a prolonged transit through the G2/M phase of the first cell cycle regardless of the cell cycle stage during treatment. This indicates that the induced cytotoxicity of CS is a function of both the cell cycle phase and the particular type of cells.

British journal of cancer, 1986

Unfed plateau-phase cultures of Chinese hamster V79-cells were treated for 1 h with various amoun... more Unfed plateau-phase cultures of Chinese hamster V79-cells were treated for 1 h with various amounts of adriamycin in the range between 0 and 10 micrograms ml-1 and subsequently either immediately trypsinized and plated to assay for survival, or reincubated in medium collected from replicate plateau-phase cultures and returned to the incubator for various periods of time before plating. Significantly less killing was observed, for the same adriamycin dose, in cells treated in the plateau-phase and plated immediately thereafter as compared to cells treated while actively growing. When cell trypsinization and plating was delayed for up to 22 h, a significant increase in killing was observed, and the survival curve obtained approached that observed after treatment with adriamycin of growing cells. Initially almost exponential kinetics were observed for this potentiation of adriamycin-induced cell killing with a t37 of approximately 2 h. Cell survival was still decreasing after 22 h of p...

Cytometry, 1989

Mitotic cells could be well discriminated from the cells in the G1-, S- and G2-phases of the cell... more Mitotic cells could be well discriminated from the cells in the G1-, S- and G2-phases of the cell cycle using pulse labeling of S-phase cells with bromodeoxy-uridine (BrdUrd) and staining of the cells for incorporated BrdUrd and total DNA content. Unlabeled G2- and M-phase cells could be measured as two separate peaks according to propidium iodide fluorescence. M-phase cells showed lower propidium iodide fluorescence emission compared to G2-phase cells. The fluorescence difference of M- and G2-phase cells was caused by the different thermal denaturation of their DNA. Best separation of M- and G2-phase cells was obtained after 30-50 min heat treatment at 95 degrees C. Mitotic index could be measured if no unlabeled S-phase cells were present in the cell culture. With additional measurements of 90 degree scatter and/or forward scatter signals, mitotic cells could be clearly discriminated from both unlabeled G2- and S-phase cells. The correct discrimination (about 99%) of mitotic cells...

Mutation research, 1992

Resistance to phosphonacetyl-L-aspartate (PALA) is caused by CAD gene amplification. The marker c... more Resistance to phosphonacetyl-L-aspartate (PALA) is caused by CAD gene amplification. The marker chromosome of a PALA-resistant cell line containing a homogeneously staining region with amplified CAD gene was introduced into PALA-sensitive Chinese hamster cells by microcell-mediated chromosome transfer. Two monochromosomal hybrids containing the marker chromosome in addition to the normal chromosome complement of sensitive cells and 1 tetraploid hybrid containing the complete genomes of donor (resistant) and recipient (sensitive) cells were studied in detail. It was shown that (i) the presence of the marker chromosome was both a necessary and a sufficient condition for the expression of the PALA-resistant phenotype; (ii) the marker chromosome underwent rearrangements in the monochromosomal hybrids, with preferential loss of non-amplified chromosomal regions, while it was not rearranged in the tetraploid hybrid; (iii) unlike the original PALA-resistant cells obtained after long-term s...

Cell and tissue kinetics

Molecular toxicology

International Journal of Radiation Biology

Carcinogenesis

Methods in Cell Biology, 1994

Methods in Cell Biology, 1990

Cytometry, 1999

Cytometry, 1995

British journal of cancer, 1986

Cytometry, 1989

Mutation research, 1992

Mutation Research/Reviews in Genetic Toxicology, 1996

1. Mutat Res. 1996 Nov;366(2):163-9. Micronuclei: a biological indicator of radiation damage. Mül... more 1. Mutat Res. 1996 Nov;366(2):163-9. Micronuclei: a biological indicator of radiation damage. Müller WU, Nüsse M, Miller BM, Slavotinek A, Viaggi S, Streffer C. Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, Germany. ...

Cytometry, 1981

Radiation-induced progression delay in Sphase and Gz-block, both depending on time of irradiation... more Radiation-induced progression delay in Sphase and Gz-block, both depending on time of irradiation in the cell cycle, were measured in synchronized Ehrlich ascites tumor cells in vitro using flow cytometric analysis of DNA content in single cells. Similar results could be obtained by the BrdUrd-Hoechst 33258 technique after irradiating asynchronous cells. BrdUrd replaces thymidine in newly synthesized DNA which is not stainable by the thymidine-specific dye Hoechst 33258. The temporal development of the fluorescence distributions after addition of BrdUrd to the medium has been measured in the flow cytometer. In asynchronous cells the mean durations of the cell cycle phases and their perturbations after irradiation could be calculated, and the data agreed with the results in synchronized cells. Division delay after irradiation consists of a small progression delay in S-phase and a block in Gz-phase. Both effects depend on time of irradiation during the cell cycle with delay in S-phase increasing in irradiated late S-cells and G2-block increasing in irradiated Gz-cells. Data from both types of experiments were used with a simple model describing the fractions of cells in the cell cycle phases after irradiation had been applied.

Cytometry, 1984

Exposure of mammalian cells to either ionizing radiation or mutagenic and carcinogenetic substanc... more Exposure of mammalian cells to either ionizing radiation or mutagenic and carcinogenetic substances can induce chromosome aberrations. These aberrations in turn may give rise to micronuclei which can be found in cells during the interphase after division. A two-step method is presented that allows separation of micronuclei from cell nuclei. They can then be measured and analysed according to their DNA content in a flow cytometer. The method involves an initial detergent t,reatment of rells followed by a second treatment with sucrose and citric acid. Micronuclei with DNA content larger than 2% of the G1-nuclei can be measured. The method is tested and compared with microscopic observations of micronucleated cells in irradiated, asynchronous, and synchronized Ehrlich ascites tumour cells growing in vitro. The agreement between the flow cytometric technique and microscopic observations is excellent when the dose-dependent number of micronuclei per cell is taken into consideration.