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Biomedical subjects

N Freudenberg

Publications and source records attributed to N Freudenberg.

30 records · Page 2Linked to original sources
PubMed1977

Effect of endotoxin-induced shock on the reticuloendothelial system. Phagocytic activity and DNA-synthesis of reticuloendothelial cells following endotoxin treatment.

There was a marked decrease in the RES phagocytic activity during the first 12 hours after injection of high concentrations of endotoxin in rats. Phagocytic activity then increased considerably, reaching maximum values on days 3 to 5 and it was still higher than in control animals 20 days later. Parallel studies on 3H thymidine incorporation showed a significant increase in the rate of DNA-synthesis of reticulum cells of the liver during the 5 days period following endotoxin injection. Peak values were obtained on day 2 when the number of labelled cell were 50 times higher than in the controls. A likely reason for the increased DNA-synthesis is a repair of RES following endotoxin induced damage but it may also represent an endotoxin induced proliferation of reticulum cells that may at least partly account for the enhanced phagocytic activity.

Animals↗
PubMed1976

Characterization of cells of the normal aortic endothelium of adult rats and changes due to endotoxin shock. I. Communication: light microscopy, autoradiography, DNA cytophotometry, and enzyme histochemistry.

Aortic endothelium of normal and endotoxin treated rats was investigated in "Häutchen" preparations by light microscopy, autoradiography, DNA cytophotometry, and enzyme histochemistry. In the endothelium of control rats the following cell populations were found: 1. Endothelial cells (90% of all cells in endothelium), characterized by the alignment of the longitudinal axis of their nuclei, their light microscopic morphology, their DNA content resp. DNA synthesis, and by their enzymatic activity; 2. mononuclear cells (10% of all cells in endothelium), identified as mature blood monocytes, mononuclear phagocytes (macrophages), and as lymphocytes; 3. granulocytes (less than 1% of all cells in endothelium). The presence of mononuclear cells and granulocytes in the normal endothelium appears to be the expression of a physiological repair process in endothelium. After endotoxin application one can observe an endothelial damage and then a repair process. During the repair of endothelium the following processes occurred: An increase of DNA synthesis particularly of endothelial cells, an aggregation of platelets on the endothelial surface, an increase in number of granulocytes and at last an increase in number of activated mononuclear cells. Participation of mononuclear cells in the physiological as well as in the pathological repair process of endothelium was shown by the present investigation. The process of transformation of mononuclear cells into endothelial cells is discussed at the same time.

Animals↗
PubMed1976

[Significance of digital examination in early diagnosis of prostate carcinoma (author's transl)].

Digital palpation of the prostate is not suitable for positive differentation between benign and malignant lesions of the prostate. Whenever a conspicuous finding is observed during a physical examination of the prostate a fine needle aspiration cytology is mandatory for eluidation of the disease. This procedure is simple and inexpensive, has a low rate of complications and high diagnostic validity.

Adenocarcinoma↗
PubMed1975

Mycosis fungoides with marked brain involvement--a case report.

The clinical course of a patient with mycosis fungoides, which could be confirmed histologically in the premycotic stage, 2 years after the onset of the disease is reported. The disease led to death after a further 3 years, during which the infiltrative and tumorous stage had appeared. At autopsy, apart from the skin changes typical for mycosis fungoides, involvement of the pia mater, plexus chorioideus, cerebrum and cerebellum was established. This constituted the only manifestation of the disease in the internal organ systems. There were no detectable neurological defects.

Adolescent↗
PubMed1975

The effect of endotoxin shock on the aortic endothelium of young rats.

Aortic endothelium of normal and endotoxin treated rats (endotoxin shock) was investigated in "Häutchen" preparations by light microscopy, autoradiography, and DNA cytophotometry. In the edothelium of control animals two cell populations were found: 1. endothelial cells which were subdivided into four groups according to their different nuclear morphology and DNA contents, 2. monocytoid cells which were taken for monocytes. In the endothelium of treated animals distinct damages of endothelial cells occurred during the period of 7 hours and 2 days after endotoxin application. Small groups of leukocytes were found in the surroundings of the damaged cells. A great number of monocytoid cells was found in the endothelial layer between the second and third day after endotoxin treatment. The monocytoid cells increased the total number of cells/mm2 on the aortic surface by one third. At the same time the maximum of DNA-synthesis of endothelial cells and monocytoid cells was reached (31-fold compared with controls). This cell proliferation is attributed to the following mechanisms: 1. repair process at sites of cell injury, 2. mitogenic effect of endotoxin. In the period between the 13th and 23rd day after endotoxin treatment all changes in the aortic endothelium returned to normal.

Animals↗
PubMed1975

Experimental investigations into the pathogenesis of endocarditis due to shock.

Generalized Shwartzman reaction (GSR) was induced in rabbits by two intravenous injections of endotoxin 24 hours apart. Consumption coagulopathy was found in all cases. Histological investigations showed an abacterial endocarditis (thrombotica or verruccosa simplex), comparable to the one seen in humans after shock, in 69% of the treated animals. Biopsies of mitral valve were investigated by electron microscopy. In the early stage of GSR the valvular alterations were characterized by an oedema of the entire valve, an increase in the number of microvesicles in the endothelial cytoplasm, and a marked enlargement of endothelial cell surface by numerous cytoplasmic projections. At a later stage autophagic vacuoles, often showing a destruction of their membranes, and degenerative changes in cytoplasmic organelles occurred in many cells of the valve. On the other hand there were cells in the endothelium, which presented a distinctly increased number of Golgi complexes and of cisternae of rough endoplasmic reticulum. In other regions ruptures of endothelial plasmalemma, as well as hemorrhages into the valvular stroma were observed. Thus predestined loci for thrombogenesis were formed. In conjunction with these structural changes three factors may be involved in the formation of endocarditis due to shock: 1. hypercoagulability in the course of consumption coagulopathy, leading to precipitation of fibrin and platelets in the circulating blood; 2. turbulences of the blood flow, which are produced by the closure of the heart valves, and favour thrombogenesis on valves: 3. direct changes of the endocardium during endotoxemia. Quantitative changes in the different compartments of intracytoplasmic organelles in many cells of the endothelium during the later stage of GSR are discussed.

Animals↗
PubMedDate not supplied

Immunocytochemical analysis of ascitic fluid due to cirrhosis. A contribution to understanding the origin of markedly atypical cells.

In some cases of ascitic fluid due to cirrhosis, benign mesothelial clusters may be observed, accompanied by markedly atypical cells that have been proposed to be abnormal macrophages, mesothelial cells or necrotic cells of hepatic origin. The aim of this study was to determine the origin of these cells with the use of a panel of monoclonal antibodies (MAbs) against cell surface antigens. Furthermore, the lymphocyte subpopulations were analyzed for a possible correlation with the presence of abnormal cells. Markedly atypical cells were found in 4 of 12 cases. They showed no phagocytosis of latex particles and were negative for MAbs My4 (CD14), HLE-1 (CD45), Leu M1 (CD15), CEA 3-13 and HEA-125. They reacted positively with BMA-120 and HLA-1. This staining pattern demonstrated the mesothelial origin of the markedly atypical cells. The profile of the lymphocyte subpopulations in the cases with markedly atypical cells was not different from the other cases. We propose that these cells are abortive cluster formations of mesothelial cells.

Adult↗