Leo Wollweber

Leibniz Institute on Aging - Fritz Lipmann Institute (FLI)

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R Stracke

Leibniz Institute on Aging - Fritz Lipmann Institute (FLI)

Alexander Rapp

Technical University of Darmstadt

Jörg‐Hermann Ozegowski

Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie e. V. - Hans-Knöll-Institut (HKI)

K. Augsten

Institute of Molecular Biology

Karl Otto Greulich

Friedrich Schiller University Jena

Michael Hausmann

Ben-Gurion University of the Negev

Stefan Vettermann

Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie e. V. - Hans-Knöll-Institut (HKI)

Detlev Behnke

Dartmouth–Hitchcock Medical Center

Birgit Perner

Leibniz Institute on Aging - Fritz Lipmann Institute (FLI)

Karl‐Otto Greulich

Heidelberg University

Cooperative Institutions

Friedrich Schiller University Jena

Institute of Molecular Biology

Institute of Molecular Biotechnology

Jena University Hospital

Leibniz Institute on Aging - Fritz Lipmann Institute (FLI)

Heidelberg University

Schiller International University

Leibniz Association

Czech Academy of Sciences, Institute of Microbiology

Charité - Universitätsmedizin Berlin

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Kinetics and Regulation of Erythrogenic Toxins Type A and C During Growth of Streptococcus Pyogenes

Zentralblatt für Bakteriologie (1996)

Jörg‐Hermann Ozegowski Leo Wollweber Stefan Vettermann Peter‐Jürgen Müller Elisabeth Günther

Streptococcus Pyogenes

Isoleucine

Interphase

10.1016/s0934-8840(96)80061-2

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Citations (4)

Steroid‐1‐dehydrogenases in nocardioform bacteria studied by electrophoresis and immuno blotting techniques

Journal of Basic Microbiology (1990)

G. Kaufmann G. Schumann Leo Wollweber E. Hüller P. Atrat

Abstract Fifteen nocardioform bacteria strains, capable of transforming steroid compounds were investigated with regard to their range of inducible steroid‐1‐dehydrogenase (St1DH) 1 activities. The St1DHs of these bacteria were compared due to their immuno reactivity in Western blot experiments with a rabbit antiserum raised against the purified St1DH of Rhodococcus rhodochrous 7030. Four strains exhibited a strong immuno reactivity, irrespective of differences in the electrophoretic mobility of the enzymes. Fivestrains revealed significantly diminished reactivities, and in five strains with a very low St1DH content, no reactivity was found. One strain, designated as Nocardia spec. 7151, exhibited a high, inducible St1DH activity, but no immuno reaction was found. The absence of immuno reactivity is discussed in connection with the considerably diminished electrophoretic mobility of this enzyme.

Reactivity

Strain (injury)

10.1002/jobm.3620300608

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Citations (10)

Variations in Cell Surfaces of Estrogen Treated Breast Cancer Cells Detected by A Combined Instrument for Far‐Field and Near‐Field Microscopy

Analytical Cellular Pathology (2002)

Petra Perner Alexander Rapp Cathrin Dressler Leo Wollweber J. Beuthan

The response of single breast cancer cells (cell line T-47D) to 17beta-estradiol (E(2)) under different concentrations was studied by using an instrument that allows to combine far-field light microscopy with high resolution scanning near-field (AFM/SNOM) microscopy on the same cell. Different concentrations of E(2) induce clearly different effects as well on cellular shape (in classical bright-field imaging) as on surface topography (atomic force imaging) and absorbance (near-field light transmission imaging). The differences range from a polygonal shape at zero via a roughly spherical shape at physiological up to a spindle-like shape at un-physiologically high concentrations. The surface topography of untreated control cells was found to be regular and smooth with small overall height modulations. At physiological E(2) concentrations the surfaces became increasingly jagged as detected by an increase in membrane height. After application of the un-physiological high E(2) concentration the cell surface structures appeared to be smoother again with an irregular fine structure. The general behaviour of dose dependent differences was also found in the near-field light transmission images. In order to quantify the treatment effects, line scans through the normalised topography images were drawn and a rate of co-localisation between high topography and high transmission areas was calculated. The cell biological aspects of these observations are, so far, not studied in detail but measurements on single cells offer new perspectives to be empirically used in diagnosis and therapy control of breast cancers.

10.1155/2002/132504

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Citations (9)

[Effect of preparation procedures on the calculation of average cell volumes from stereological data].

PubMed (1980)

Leo Wollweber Fritsch Rs R Stracke U Gothe

The shrinkage of peritoneal cell during the electron microscopical preparation was investigated by means of a special device. Independently of the procedure of fixation after critical point drying the cells exhibit only 54 to 59% of the original diameter (residual volume about 18%). The reduction of cell diameter after Epon embedding is about 25%, corresponding to a residual volume of 40%.

Stereology

Shrinkage

Residual volume

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E. Kurstak, Enzyme Immundiagnosis. X + 235 S., 56 Abb., 13 Tab. Orlando—San Diego—New York—Austin—Boston—London—Sydney—Tokyo—Toronto 1986. Academic Press. $ 34.95. ISBN: 0‐12‐429 745‐5

Journal of Basic Microbiology (1988)

Leo Wollweber

10.1002/jobm.3620280814

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Lectin binding sites and anionic components related to differentiation in the prenatal rat cerebral cortex.

PubMed (1985)

Gert Brückner L.D. Muller Leo Wollweber R. Samtleben D Biesold

The location of lectin binding sites and of anionic components was studied in the embryonic rat cerebral cortex after the formation of the cortical plate at embryonic day 18. The cortical layers advanced in differentiation, i.e. the sub-plate region and the marginal zone, showed a predominant staining with peroxidase conjugates of wheat germ agglutinin (WGA), peanut agglutinin (PNA), and after immunocytochemical detection of PNA binding sites. This pattern was obtained also with the colloidal iron hydroxide staining method. In contrast to this, the binding of concanavalin A and of succinylated WGA did not reveal a prevalent staining of the sub-plate region and the marginal zone. The further histochemical analysis of the substances responsible for the selective staining of these layers was performed by lipid extractions and by enzymatic treatment of the tissue sections with trypsin, hyaluronidase or neuraminidase prior to the binding of lectins or colloidal iron. The results obtained indicated high concentrations of sialylated galactosylglycoproteins in coexistence with glycosaminoglycans. Electron microscopy was performed with peroxidase conjugates of WGA and PNA. Binding sites of both of the lectins in the sub-plate region and in the marginal zone were located mainly at cell surfaces of the different cellular structures. The most intensive binding of WGA and PNA was detected at the surface membranes and at intracellular material of amoeboid microglial cells and astrocyte-like cell processes. It can be concluded that in distinct brain areas during early differentiation specific glycoproteins in coexistence with glycosaminoglycans are situated at, or associated with cell surfaces in high concentrations. The identical histochemical features previously described in mesenchymal tissues suggest that these glycoconjugates might be related to common morphogenetic processes in which non-neuronal cells of brain and body are specifically involved.

Peanut agglutinin

Soybean agglutinin

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Citations (23)

Effect of several fixatives on the density of concanavalin A binding sites of murine peritoneal macrophages determined by fluorescence microscopy and X-ray microanalysis.

PubMed (1986)

Th. Peschke A. Gabert Leo Wollweber K. Augsten

The influence of various fixatives (glutaraldehyde, formaldehyde, OsO4) on the retention of antigenicity of peritoneal macrophages was studied by means of fluorescence microscopy, scanning electron microscopy, and X-ray microanalysis. After fixation with formaldehyde the Concanavalin A (Con A) binding sites were found to be highest, whereas the fixation with OsO4 results in loss of many binding sites. The fluorescence microscopic investigations of glutaraldehyde fixed cells is impaired by fixative induced fluorescence. Therefore X-ray microanalytical determinations show better results for these cells than fluorescence microscopic measurements. On contrary to direct labelling method the number of unspecific Con A binding sites on peritoneal macrophages labelled with the sandwich method is negligible.

Glutaraldehyde

Fixative

Microanalysis

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Citations (6)

The distribution of the tail moments in single cell gel electrophoresis (comet assay) obeys a chi-square (χ2) not a gaussian distribution

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis (1998)

Eckhard Bauer Rolf-Dieter Recknagel Ursula Fiedler Leo Wollweber Claudia Bock

Comet Assay

10.1016/s0027-5107(97)00246-7

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