Biomedical subjects
Publications and source records attributed to J C Stockert.
After treatment with Alcian blue at high temperatures, nuclei from chicken blood smears showed an intense staining reaction, which proved to be dependent on the DNA content of chromatin. The possibility that interactions between the phthalocyanine chromophore and unpaired bases accounts for this temperature-dependent staining of chromatin is briefly discussed.
After treatment with neutral red at low concentrations (10(-6), 10(-5) M), the chromatin of chicken erythrocytes shows an intensive red fluorescence, which is reduced or practically abolished when nuclei become stained by using the dye at concentrations higher than 10(-4) M. Both the fluorescence and staining reactions are dependent on the DNA content of chromatin. Neutral red fluorescence of nuclei increases considerably after treatment with inorganic cations (Al3+, Ba2+), while previous treatments with methylene blue reduce the fluorescence intensity. The possibility that chromatin fluorescence depends on the intercalative binding of neutral red is suggested.
Treatments of chicken blood and Ehrlich ascites tumor smears with hematoxylin solutions give a fluorescence reaction in chromatin, basophilic cytoplasm and leukocyte granules. In these structures the fluorescence emission increases upon dye aging and prolonged staining times. We present a preliminary spectral analysis suggesting the possibility to employ hematoxylin as a fluorochrome.
Semithin and thin sections of glutaraldehyde-fixed, epoxy resin-embedded animal tissues were treated with solutions of oxidized p-phenylenediamine (PPD). This method is suitable to reveal the general morphology of tissues in light microscopy, showing a high staining degree in some polyanion containing components. Posttreatments of thin sections with gold chloride solutions give considerable electron opacity in PPD positive structures.
Treatment of cell smears, paraffin, and Epon tissue sections with aqueous solutions of curcumin results in a green fluorescence reaction in chromatin under violet-blue excitation which is abolished after extraction procedures with DNase and TCA. The selective fluorescence characteristics of curcumin support the possibility of employing this dye as a new fluorochrome.
Aqueous solutions of a yellow and highly fluorescent derivative from dimethyl-POPOP, obtained by treating a chloroform solution of this oxazole scintillator with dimethylsulfate, induce a strong blue-green or yellow-green fluorescence in chromatin DNA under ultraviolet (365 nm) or violet-blue (436 nm) excitation, respectively. It is suggested that this new and selective fluorescence reaction could originate from binding of the oxazolium derivative into the minor groove of DNA.
The structure of specific granules from horse eosinophil leukocytes is still largely unknown. In this work, electron microscopical studies of horse eosinophils reveal that the large cytoplasmic granules contain an external membrane, a matrix of less density, and a dense (non crystalline) core. Round vacuolar inclusions of matrix materials were often observed within the cores. Horse eosinophil granules showed a considerable heterogeneity, and three morphological types could be identified according to structural features of the core and matrix.
Treatment of chicken blood smears and semithin sections from Epon-embedded mouse tissues with aqueous solutions of the 3-aminonaphthalimides FA-142, FA-2043, and FA-2143 induced a strong green-yellow fluorescence of chromatin under violet or violet-blue excitation. Chromatin emission was abolished by previous DNase or hot TCA treatment. The use of 3-methoxy (FA-655) and 3-nitro derivatives (M-4212 and M-12210) resulted in very weak fluorescence of chromatin. Absorption maxima at 346 and 408 nm and an emission peak at 570 nm were observed for the free compound FA-142. Fluorescence properties open new and interesting applications for some of these antitumoral and DNA-intercalating naphthalimides.
The technique of osmium tetroxide fixation followed by a treatment with p-phenylenediamine was applied to mouse testes in order to analyze pachytene nuclei. Observation of Epon semithin sections (0.25--0.5 micrometer) in conventional electron microscopy revealed the presence of positively stained synaptonemal complexes surrounded by unstained chromatin. The present results show that by using this method a suitable contrast and resolution can be achieved for semithin sections, which facilitates the topographical study of synaptonemal complexes.