Acta histochemica. Supplementband最新文献

We investigated the proliferation of urothel of the rat after unilateral nephrectomy and application of DBN with drinking water in various doses. We controlled the measurement of proliferation with 3H-thymidine. The important results of our experiments with DBN-application and unilateral nephrectomy were: 1. the tumour-incidence is higher and 2. the tumour-appear is earlier than in experiments with only DBN.

The investigations are carried out in 29 human fetal pancreases between the 10th and 19th week of age. Mitosis restricted to the duct epithelium in the 10th to 13th week. In the 14th week start the mitotic activity in the islet parenchyma. The mitotic activity decreased from the 10th to the 13th week, increased to the 15th week and decreased once more to the 19th week.

Two Triton-X-100-insoluble cytoskeletal fractions were prepared from washed human blood platelets by centrifugation: a low speed sediment (TP) and a fraction recovered as ultracentrifugation pellet (UP). Glycoproteins associated with both fractions prior to and after different times of thrombin activation were analyzed by electrophoretic techniques. In the TP fraction of unstimulated platelet the major membrane glycoproteins (GP) Ib and Ia were detected. After thrombin stimulation there is a rapid increase of GPs Ia, Ib, IIIb and a Mr 250,000-GP and a slower appearance of GPs IIb and IIIa in this fraction. The UP fraction contains mainly GPs Ib, Ia, IIb, IIIa and a Mr 250,000-GP. Thrombin activation does not cause any significant changes in the glycopeptide pattern of this fraction.

Traumatic haemorrhagic shock in male rats caused an increase of cytoskeletal, especially filaments, in the numerous endothelial cells of the mesenteric microvessels during an examination period of 15 minutes to 2 hours. The filaments become ultrastructurally visible especially in endothelial cells with an enhanced "activity", in case of attachment of cells and in narrow capillaries with stasis. Additional investigations of these findings with other results will be carried out.

We report on the use one-parameter DNA flow cytometry in the evaluation of the proliferation kinetics of malignant tumors. We emphasize the need of a background correction of the histograms in cases where the S-phase portion is used as a prognostic parameter for patients with malignant tumors. Flow cytometric investigations during the last 12 years with many thousand samples of human malignant tumors have shown that the described methodology can be used routinely as "assistant diagnosis" for a distinct group of tumors. These tumors comprise carcinomas of the breast and the ovaries and probably also of the endometrium. Regarding the relevance of the method for oropharyngeal squamous carcinomas, gliomas and meningiomas we have to await longterm results. In contrast, at present the method does not seem to be applicable for colorectal carcinomas and it is apparently not suitable for stomach carcinomas. It is also questionable whether data on proliferation kinetics gained in human tumors transplanted to nude mice can be as a basis in chemotherapeutic treatment of patients from whom the tumor originated.

DNA content was measured by means of Feulgen cytophotometry in myocyte nuclei of sinoatrial und atrioventricular nodes, Purkinje cells, left and right atria and ventricles from normal and hypertrophied human hearts both on 12 microns sections and on squash preparations of myocardial tissue. In contrast to ordinary atrial and ventricular myocytes of normal and hypertrophied adult hearts, which contain mostly polyploid nuclei, the DNA content in 74 to 88.5% of myocyte nuclei from sinoatrial and atrioventricular nodes does not exceed 2 c. Unlike nodal myocytes in Purkinje cells of hypertrophied adult heart there are 97 to 99.5% of polyploid nuclei, 49 to 88% of them displaying octaploid and higher DNA values. Myocytes of highly hypertrophied atria contain nuclei of considerably higher ploidy level than those of normal atria. Percentage of binucleated cells show a 4-fold increase in hypertrophied atria compared with normal ones. The total area of nucleoli per nucleus is proportional to the degree of ploidy. Number of sex chromatin bodies counted simultaneously with DNA measurements on sections of atrioventricular node and on squash preparations of atria and ventricles is correlated with ploidy level. Judging by correlations between the number of sex chromatin bodies and DNA content in nuclei, on one hand, and between the total area of nucleoli per nucleus and the degree of ploidy, on the other, the mitotic endoreduplication (true polyploidization) is responsible for the increased DNA content in nuclei of conductive system, atrium and ventricle.

Visualization of rIFN-alpha 1 and -alpha 2 receptors on MDBK-cells was done by means of a two step method with gold-labelled monoclonal anti IFN-antibodies in the SEM. This binding showed a marked dependency from the temperature, concentration of the rHu-IFN, prefixation of the MDBK-cells, and time of incubation. This results are in agreement with findings of classical virological methods. By means of SEM was shown that the distribution and amount of the IFN-receptors on MDBK-cells depends strongly on the cell cycle and that not each was labelled. The results were discussed in connection with structural-functional alterations of the cytoskeleton.

In the present study the influence of the embedding technique on the dye-substrate-interaction of the Feulgen reagent has been investigated. Pieces of rat liver and of human lung tumours were fixed in formaline, Carnoy's or Bouin's solution or in SuSa and embedded in paraffin (P) or in glycolmethacrylate (GMA). Sections were stained with the pararosaniline-Feulgen-reagent. Mean optical density (MOD) of cell nuclei was measured with an image analyzer. GMA required longer times for hydrolysis and staining than P. the plateau phase of acid hydrolysis was longer in GMA. In general MOD was significantly lower in GMA than in P. The ratio of MOD of lymphocyte nuclei versus diploid basal cell nuclei in lung tissue was 0.97 in GMA and 0.88 in P, respectively. We presume that cross-linking of GMA monomers during polymerization stabilizes hydrolysed DNA. Steric factors are responsible for the slow diffusion of the dye-molecule. The influence of the embedding medium on the stoichiometry of the Feulgen stain has to be carefully considered for statistical evaluation of DNA-histograms.

Influenza C virus uses 9-O-acetyl-N-acetylaneuraminic acid (9-O-acetyl-Neu5Ac) as a receptor determinant for attachment to cells. The virus contains an acetylesterase which releases acetyl residues from position C-9 of sialic acid thereby inactivating the receptors. A synthetic sialic acid analogue, 9-N-acetyl-Neu5Ac, was attached to cell surface glycoconjugates by purified sialyltransferase and analyzed for its ability to substitute the 9-O-acetylated sialic acid. Erythrocytes which have been modified to contain either 9-O-acetyl-Neu5Ac or 9-N-acetyl-Neu5Ac were agglutinated by influenza C virus to the same titer. However, in contrast to the 9-O-acetyl group the 9-N-acetyl residue is resistant to cleavage by the viral acetylesterase. This characteristic property (recognition as a receptor determinant by influenza C virus, but resistance against the action of the receptor-destroying enzyme) makes this synthetic analogue a valuable tool to analyze the role of the receptor-destroying enzyme for an influenza C virus infection.