Experimentelle Pathologie最新文献

Myocardial mitochondria of the left ventricle of 16 adult, 6-month-old, male Wistar rats, 11 of which were trained animals which had undergone different periods of swimming (45, 180, 360 hours) of different load(½ up to a maximum of 5 hours per day) and 5 of which were coeval untrained controls, were subjected to a morphometric analysis. No significant differences were observed in the volume and surface density of the mitochondrial cristae between the former and the latter animals. This result is attributed to the dilution effect as a result of an increase in the proportion of the volume of the mitochondria. For this reason only the “specific” surface values in relation to the mitochondrial volume can be regarded as representative parameters for assessing the surface capacity of the inner membranes as a structural equivalent of mitochondrial metabolism. The specific volume and surface density of the mitochondrial cristae increases by 101% and 25% respectively after 45 hours of training. Given a uniform training load, the changes recede as a sign of the completed adaptation of the mitochondria. The surface of mitochondrial cristae per unit myofibrillar volume (cristae/myofibrils ratio) is statistically unchanged during 45–180 hours of exercise indicating a proportional increase of ATP-synthesizing structures in the hypertrophied heart. The significant reduction in respiratory membrane capacity after 360 hours of intensive physical load is interpreted as an effect of overadaptation.

Intrarenal injection of a crude E. coli extract (endotoxin-antigen-complex) induced malakoplakia in rats. Beside the granulation tissue the proximal tubular epithelium showed a strong phagolysosomal response — especially in two-three weeks —, thus becoming very similar to the Hansemann cells of the malakoplakia granulation tissue. This malakoplakia alteration of the epithelium if very severe sometimes led to necrosis or it was segregated inside the epithelial cells. Later on an atrophy of the tubules developed similar to the atrophy of different etiology, but the remaining cells often contained a striking number of residual bodies. It is suggested that the tubular granulated cells of megalocytic interstitial nephritis regarded as identical with renal cortical malakoplakia also have a tubular epithelial origin.

DDVP is an organophosphate pesticide whose neurotoxicity, in the form of cholinesterase inhibition, is well-known. Rats, weighing 200–225 g were given intraperitoneal injections of 3 mg/kg. DDYP daily for 10 days. Following perfusion-fixation, ultrathin sections of the cerebellum and spinal cord were examined with an electron microscope. A large number of electron-dense bodies exhibiting electron-lucid vacuoles were discernible in the perikarya of cerebellar neurons. Aggregations of mitochondria were also seen. Myelin-figures in dendrites and axons of the spinal cord were detected. Evidence of oedema was evident in the spinal cord.

The response to artificial endotoxinemia was studied in adult dogs. Granulocyte-macrophage colony stimulating activity (CSA) in lung tissue and blood was measured along with the number of circulating granulocytes and myeloid committed stem cells (colony forming units, CFUc). Acute endotoxinemia induced a measurable CSA increase in lung tissue before being detectable in blood. Granulocytes, rapidly removed from the circulation, showed no release of CSA during sequestration. These experiments demonstrate that the process of endotoxin recognition and subsequent transition into a myelopoietic stimulus is mediated by cells belonging to tissue; mature granulocytes, involved in the defence against bacterial infection, do not release activity that promotes growth of immature myeloid cells.

In vitro hepatic synthesis of lipids starting from l-¹⁴C-acetate was studied in rats made diabetic by subcutaneous alloxan administration (175 mg/kg b.w.). A second group of diabetic rats was treated with lente insulin.

In the alloxan-treated rats, a decrease was observed in hepatic incorporation of l-¹⁴C-acetate into phospholipids, triglycerides and esterified cholesterol; there was an increased incorporation into nonesterified fatty acids (NEFA) and free cholesterol.

Insulin administration restored lipid synthesis values to normal.

On histologic examination, an intranuclear glycogenesis was observed in the hepatocytes of the alloxan-treated rats, along with severe hepatic necrosis; the latter however, only in rats sacrified on the 3rd day. Hepatic steatosis with small, medium and large droplets was present in the insulin-treated rats; signs of cellular degeneration were less evident.

Cultivated normal and transformed fibroblasts of the mouse (short-term cultures of lung fibroblasts and L-cells) have been implanted onto the chorioallantoic membrane of the chick embryo (CAM). Both cell types formed macroscopically visible nodules on the CAM where they induced a weak angiogenic reaction. Labelling of the cells with activated charcoal or 3H-thymidine gave evidence of their invasion into the CAM mesoderm, where they induced the formation of new capillaries. The successive multiplication of the cells led to the formation of tumours, resp. tumour-like cellular accumulations in the hypertrophied mesoderm of the CAM. Treatment of L-cells with the protease-inhibitor Contrykal reduced the invasive properties of the cells. The results presented clearly demonstrate invasive and angiogenic properties of the normal and malignantly transformed cell cultures of the mouse used in our experiments.

The effect on antigen uptake and digestion in macrophages and polymorphonuclear leukocytes (PMNL) of 2 compounds of a series of benzimidazole nitrogen mustard derivatives has been investigated by ultra structural quantitative stereological techniques in order to enlighten some mechanisms of the immunosuppressive effect of especially one of the chemicals. One compound, ZIMET 3393 (Cytostasan®), is a powerful cancerostatic with only moderate immunosuppressive side effects while ZIMET 3164 proved an effective immunosuppressant with low cytostatic action.

Results of a recent study (Fritsch and Gothe 1979) have lent support to the hypothesis that immunosuppression can be induced by an inhibition of antigen processing by macrophages through a membrane-stabilizing effect of the chemicals under investigation. It can be shown in the present study that in the case of ZIMET 3164 an increased competitive antigen phagocytosis and digestion takes place in PMNL. This alternative pathway of antigen processing is suggested to be ineffective with respect to enhancement of immune responses compared with that through macrophages, thus providing an additional possible mechanism of chemical immunosuppression.

By means of modelling arthritis by horseradish peroxidase it was possible to reproduce a process corresponding to immune synovitis. A considerable reduction of immunomorphological phenomena in joints, lymphoid tissue, heart, liver and kidneys was favoured by application of lymphoid tissue extracts. Comparison between the extracts of spleen and lymph nodes showed a more pronounced effect of spleen extract.

The present study is concerned with the interaction of rat endo- and mesothelium with homologous erythrocytes under various conditions of pretreatment and incubation. Its findings show rat endo- and mesothelial cells

• a)

  nonadhesive to native or pretreated erythrocytes irrespective of the presence of gamma-globulin in the medium,

• b)

  devoid of primary or cryptic receptors sensitive to the Fc segment of the IgG molecule, and

• c)

  provided with binding sites at the oxidized glycocalyx which together with receptor groups of modified erythrocytes share the same class of IgG.

The object of the study was the cerebral cortex of newborn rat. Tissue samples for examination were collected from the 2nd to the 8th hour after birth. Experimental material was the tissue of control animals and newborns whose mothers had been treated with both ethanol and pyrazole throughout gestation, and also with either ethanol or pyrazole alone. Ethanol and pyrazole were administered by gastric tube, ethanol at doses of 8.0 g/kg body weight, pyrazole at doses of 36 mg/kg body weight. The results indicate that ethanol ingested by the mother during gestation inhibits cell maturation in the cerebral cortex, whereas the combined administration of ethanol and pyrazole produces a highly toxic action. Its morphological exponent are symptoms which support the diagnosis of encephalitis congenita symptomatica toxica.