Microscopica acta最新文献

After staining with thionin at low concentration (less than 10(-5) M), the masses of condensed chromatin in chicken erythrocyte nuclei show a red fluorescence under green excitation, which is abolished when they become stained by using concentrations higher than 10(-4) M. The possibility that intercalative binding of a hydrophobic component from the dye solution into DNA accounts for this fluorescence reaction in chromatin is briefly discussed.

The construction of a microscope perfusion respirometer (MPR) for simultaneous recording of cellular respiration and microscopic morphology is described. All light microscope techniques for living cells (e.g. phase contrast, differential interference contrast (DIC), fluorimetry) can be applied to the monolayer cells grown on a coverslip. The main constituents of the MPR are a) a precision operating perfusion pump (constant volume output), b) a modified Dvorak-Stotler perfusion chamber, c) a special holder for the Clark-type oxygen probe, d) gas-tight connections of stainless steel tubing with dead volume-free fittings, and e) a temperature control unit. The cell material, established XTH (Xenopus laevis tadpole heart) cell is characterized. Examples of operation are presented, concerning a) normal respiration, b) respiration during uncoupling of oxidative phosphorylation by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), and c) lactate production under anoxia. The corresponding mitochondrial in situ-morphology is demonstrated on photomicrographs. Details of construction and application are discussed. This new technique is supposed to extend the use of cell cultures instead of animal experiments in pharmaceutical routine tests.

Apart from the applicability of the tannic acid-phosphomolybdic acid-Levanol-Fast Cyanine 5RN method for the identification of muscle myosins in Carnoy-fixed tissues, this technique can also be applied on tissue sections fixed with formalin or carbodiimide. The use of carbodiimide as a fixative offers, in general, a superior staining of the tissues with safranine and Levanol. Using a slightly modified procedure, reduction of staining time in Levanol, moreover, allows a differentiation between cells containing different amounts of myosin. This is illustrated by means of a number of rat tissues.

Four antidiarrheal drugs (China clay, bentonite, pectin, Kaoprompt H) are fed to mice by a gastric probe. Eight hours later, samples are taken from small intestine and colon to study the behaviour of the drugs in the gut. Any interactions with the brushborder of the villi at best are possible in the case of pectin. The viscosities of the suspended drugs depending on selected steps of pH are tested. The results are supporting the histological findings. The mechanical effects which may be put on the gut by the drugs are discussed.

Veneous blood-citrate samples of patients with infectious mononucleosis were stained with DAPI, a newer fluorochrome (4',6-diamidino-2-phenylindole) to demonstrate the "large atypical lymphocytes" associated with this disease. As a result of the capacity of DAPI to stain DNA and certain acid mucopolysaccharides, a rapid detection of the pathognomonic white blood cells could be achieved. Most of them revealed the well known indented or lobulated nuclei and vacuolated (foamy) cytoplasm. Others exhibited kidney-shaped nuclei, often filled with yellow-fluorescent tiny granula. In our view, the rapid, specific and sensitive DAPI-technique for detecting pathognomonic blood cells in patients with infectious mononucleosis can be considered an improved microscopic method.

The aim of this investigation is to develop the best approximation procedure for calculating the volumes of the perikarya of oriented cortical neurons. About 1119 nerve cells (area 6 after Brodmann) were identified. The medial cross section (projection area) and the maximal diameter of each cell was measured. The calculation is based on stereometrical models (sphere/cone/ellipsoid). The volume of a sphere of equal projection area has to be corrected for the actual shape of the cell type concerned (conical for pyramidal cells and ellipsoidal for granule and spindle cells). The correction factors are obtained by two different types of graphs. The procedure suggested depends on the available equipment. When working with systems which store only the projection area, the factor obtained for granule cells (0.9) should be used for all cells up to a projection area of 120 microns 2. Larger cells should be corrected by the factor derived for pyramidal cells (0.85). In connection with systems which provide the maximal diameter as well, the correction factors can be worked out by estimating the axial ratio of the neurons. Advanced systems like the Videoplan are able to calculate factors for individual cells.

When reconstructing the volumes of organs, or other individual bodies, the areas of these structures are usually determined with the help of serial sections and the volume thus estimated. The actual number of serial sections that have to be taken into account, whilst arranging such a study, is of great importance. This present paper shows that about 20 equidistant sections are sufficient in order to determinate the volume, even that of extremely irregular formed bodies, whereby the error will not exceed 5%.

Using the naphthol AS-D-chloroacetate esterase method and the indirect immunoperoxidase technique we tried to stain selectively granulocytes in the lung and in the liver. For the immuno technique we used an antibody raised in rabbits against dog granulocytes, which were prepared by a new separation technique. Comparing the two staining methods we found the immunoperoxidase to be superior at least for quantitative evaluation. In a pilot study with polytraumatized dogs versus controls we could detect a more pronounced leucostasis within the trauma group. This was similar to a parallel study which used radioactive labeled granulocytes where a significant increase could be shown. Granulocytes, at least in part, seem to be important for cellular changes within the "lung in shock".