Search PubMed⌕ Search

Biomedical subjects

G Kiefer

Publications and source records attributed to G Kiefer.

At least 55 records · Page 3Linked to original sources

DNA content of mycosis fungoides cells.

DNA content of mycosis infiltrate cells was measured in 5 patients with the Feulgen cytophotometric method in the plaque and tumor stages. In addition, the infiltrate cells were differentiated cytochemically into histiocytes and atypical lymphoid cells with NaF-sensitive naphthol-AS-D-acetate esterase. In no case was an aneuploid stem line demonstrated. However, increasing duration of the tumor stage was associated with a larger proportion of tetraploid and octoploid cells. The DNA histograms also exhibited a local proliferation of atypical lymphoid cells. This proliferation was arrested by cytostatic therapy. Comparison with semi-thin-sections of tumor tissue showed that the mycosis fungoides cells are atypical lymphoid cells. These DNA measurements do not contradict the concept of limited aneuploidy, as reported in cytogenic studies. Thus mycosis fungoides fits in with the DNA distribution pattern in the group of lymphomas.

Adult↗

Comparative studies of the incorporation inhibition of radioactive nucleotides and amino acids in vitro under the influence of adriamycin, bleomycin, and sodium arsenate.

The incorporation of 14C-marked nucleotides and amino acids into the nucleic acids and into the cellular protein of PHA-stimulated human lymphocytes was inhibited variably by increasing doses of Adriamycin, Bleomycin and Na2HAsO4. The findings, which were obtained with the aid of the liquid scintillation counter and partly by means of 14C-thymidine-marked autoradiographies shows clearly that Adriamycin causes the strongest incorporation inhibition. In contrast to this, the inhibition caused by Bleomycin and arsenate is considerably less destructive. It was shown by means of cytophoto metrical examinations that Adriamycin is capable of fixing cells in the G2 phase and in the S phase. Cells react similarly to Bleomycin and arsenate. The differential inhibition of nucleic acid and protein metabolism induced by Adriamycin, Bleomycin and arsenate is correlated with a varying responsiveness of lymphocytes to the cytostatically effective substances.

Arsenates↗

DNA and the cell cycle.

The cell cycle and its significance for pathology is reviewed. The molecular basis and questions of regulation in the cell cycle are discussed, along with deviations from the normal cycle in the form of polyploidy formation and aneuploidy in tumor cells. Automated prescreening processes may play a role in the future in daily routine diagnosis. Methods of cytophotometry with the possibility for objective pattern recognition will become significant in pathology in many ways, both in research and in routine work.

Aneuploidy↗

[Fumaric acid monoethylester: Effect on DNA-synthesis and preliminary findings in experimental studies in animals (author's transl)].

The incorporation of 14C-Thymidin into DNA of cultured human lymphocytes is depressed by added fumaric acid monoethylester (FSME) depending on the dosage of FSME. The decreased radioactivity in DNA as measured by scintillation counting is paralleled by a concomitant decrease in the labelling index in autoradiograms. Decreasing radioactivity is therefore due to a lower number of DNA synthesizing cells. No selective inhibition of proliferation during one of the cell cycle phases was observed. Especially a G2-block known from other cytostaties is absent. A mean dosis of 6.88 mg FSME per g body weight administered intraperitoneally is lethal to mice. The animal die from diffuse necroses of heart muscle cell. Alterations of other organs are less prominent. At lower doses of FSME the morphology of the organs investigated is altered to a smaller degree.

Animals↗

Mitochondriosis of the hepatocytic cytoplasm in rachitic rat liver after calcitonin-treatment (a cytophotometric and morphometric study).

A calcium-rich rachitogenic vitamin-D deficiency and additional doses of calcitonin cause serious changes in cell structure and metabolism, which can be demonstrated by cytophotometry and morphometry. The experiments were made with 9 male juvenile Wistar rats. 6 animals were kept on a vitamin-D deficient diet for 6 weeks and 3 of these animals got injections with salmon-calcitonin S.C. during the last 14 days every second day. The remaining 3 animals, fed with altromin-R standard diet were kept for control purposes only. The morphometric analysis of the liver parenchymal cells was based on the statements by Weibel and the cytophotometric examinations were made according to the Sandritter technique. As a consequence of the altered metabolic condition a great volume reduction of cells and cell nuclei is found in the animals with vitamin-D deficiency, which were treated with calcitonin. In comparison with the control animals the hepatocytes show hardly any tetraploid nuclei, which points to an inhibited polyploidization. The cytoplasm shows an oncocytic transformation with megamitochondria. As reason for this mitochondriopathy an extreme and abnormal growth as well as a mutation of the mitochondrial genom are under discussion. Furthermore the total endoplasmic reticulum (volume and membrane surface), the peroxisomes and the ribosomes are strongly reduced. Due to the serious cell injury the other organelles are also reduced in number and volume, which points to a chronic hypocalcemia.

Animals↗

[Influence of hypothyreodism on the quantitative Karyo- and cytoarchitecture of rat hepatocytes. (A morphometrical and cytophotometrical study on rat hepatocytes 3 weeks after thyreoidectomy) (author's transl)].

INTRODUCTION: Thyroid hormoned influence the quantitative cytoarchitecture of hepatocytes by stimulating the membrane synthesis of mitochondria and ergastoplasm. The cellular and nuclear changes produced by thyroidectomy were analysed cytophotometrically and morphometrically. MATERIAL AND METHODS: 21 days after thyroidectomy the liver tissues of 10 male Wistar rats were examined. 5 sham-operated animals served as controls. All rats received Altromin-R-standard diet. The cytophotometric analysis is based on the method described by Sandritter. The morphometric study was carried out following Weibel's methods. RESULTS AND DISCUSSION: As a consequence of the changed cellular metabolism, smaller hepatocytes and nuclei (but larger nucleoli) are found in the hypothyroid rats. As compared with controls, hepatocytes hardly show tetraploid nuclei, which is due to inhibited polyploidisation. The mitochondrial content has become considerably smaller in the hypothyroid hepatocytes. The cristal membranes, the mitochondrial and peroxysomal volume per hepatocyte show a similar reaction pattern, which is considered to be a sign of reduced cellular metabolism. The volume loss of the ergastoplasm confirms this assumption.

Animals↗