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Biomedical subjects

I E Richter

Publications and source records attributed to I E Richter.

At least 19 recordsLinked to original sources
PubMed1979

Effect of cutaneous human or mouse burn toxin on the metabolic function of isolated liver cells.

Studies on isolated perfused rat livers 5 days after either a sublethal burn or an i.p. injection of human/mouse burn toxin showed a significant inhibition of the glucose/urea synthesis and the ATP production concomitantly with ultrastructural mitochondrial damages. A direct specific effect of these burn toxins on enzymatically isolated liver parenchyma cells was found either after direct incubation of the isolated cells with the compound or 5 days after injection of the toxin to the animals followed by the isolation of the cells. Control experiments were performed with the "native" non-toxic precursor from normal skin. Liver cells of rats pretreated with the toxin showed an 100% increase of the amino-acid release while this increase was 70% after direct toxin incubation. Glycogen synthesis from lactate, alanin and fructose was significantly decreased in both toxin groups while the glucose synthesis was not altered. The degree of the inhibition of the glycogen synthesis was directly correlated to the number of ATP-dependent metabolic steps. A disturbance of the oxygen transfer system by structural damages of the mitochondria seems to be the basic mechanism for these specific metabolic alterations due to ultrastructural mitochondrial damages.

Adenosine Triphosphate↗
PubMed1977

[Observations of the surface of the articular cartilage after treatment with hyaluronidase (author's transl)].

1. The articular surfaces of the femoral head of rats have been studied by scanning electron microscopy after in vitro treatment with hyaluronidase. 2. The cartilage surface has been digested mildly by the buffer medium (control). 3. The matrix of the cartilage has selectively been removed by the hyaluronidase. 4. Chondrocytes have been seen on the surface after treatment with hyaluronidase for a longer period. 5. We discuss the result of enzymatic digestion.

Animals↗
PubMed1977

[The pros and cons of haemoperfusion (author's transl)].

6 patients with severe self-poisoning were treated by charcoal-haemoperfusion in our centre up to now. In four of them (all suffering from sleeping drug overdosage) the treatment was successful. Two patients with intoxications by agrochemicals died in spite of haemoperfusion. Side effects of haemoperfusion were drops of blood pressure and platelet count, depletion of immune bodies, and adsorption of remedies. Up to now, the indication for haemoperfusion has to consider these secondary actions of encapsulated charcoal as inevitable.

Arteries↗
PubMed1976

Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema.

The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.

Animals↗
PubMed1976

[The fine structure of liver sinusoids after perfusion fixation with various pressures. A transmission and scanning electron microscopic study (author's transl)].

The fixation of rat liver by perfusion with glutaraldehyde with different pressures has been investigated. For this study adult male albino rats were used. Rat livers were fixed by perfusion through the abdominal aorta according to the method of FORSSMANN et al. (1967). Perfusion pressures varied from 30 to 210 mmHg. A continuous complete endothelial lining of liver sinusoids could be visualized with TEM and SEM after fixation with perfusion pressures lower than 100 mmHg. Three different regions could be noticed in the endothelial cell: 1. prominent nucleous region, 2. compact cytoplasmic processions containing mitochondria and ergastoplasma, 3. delicate fenestrated cytoplasmic areals. As a rule the fenestrations were localized in groups, s.c. sieve plates. After perfusion fixation with pressures above 100 mmHg the endothelial lining of liver sinusoids appeared similar to a wide-meshed net. The sieve plates were destroyed, and numerous defects could be found in the endothelial cells. Hepatocytes showed vacuoles which seem to be due to invagination of the cellular membrane. For the development of artifacts even with physiological perfusion pressures in the aorta (110 mmHg), the content of procaine in the rinsing solution is responsible. Eliminating the function of arteriols leads to unphysiological pressure effects in the sinusoids.

Animals↗
PubMed1976

[On the influence of hypoxia on the sinus endothelial cells of rat liver. A scanning and transmission electron microscopic investigation (author's transl)].

Fine structural alterations of liver sinusoids in young and adult albino rats breathing 6% oxygen in nitrogen at normal atmospheric pressure for periods from 3 to 30 h were described by use of TEM and SEM. After short-term hypoxia the fenestrated areas of endothelial cells were partially destroyed. After long--term hypoxia wide gaps could be visualized in the endothelium, too. In the liver specimens of all hypoxic animals electron lucent membrane bounded blebs arose from the endothelial lining. Cytoplasmic protrusions of hepatocytes bulged into the sinusoidal lumen. In the space of Disse and the sinusoidal lumen bleblike corpuscles and parts of cytoplasmic membrane being discharged from liver cell vacuoles could be observed. The find structure of liver sinusoids in hypoxia was very similar in young and adult albino rats. The findings suggest a discharge of metabolites and cellular components from endothelial cells and hepatocytes in a state of energetic insufficiency by forming cellular blebs and protrusions. It was supposed, that the combined effects of hypoxia and shearing of circulating blood were responsible for the development of holes and gaps in the endothelial lining.

Animals↗
PubMed1976

[The structure of meningeal granules based on light- and scanning electron microscopic studies].

The granula meningica of man (medium and advanced age) were investigated by means of light microscopy and scanning electron microscopy. We established the following: 1. The endothel of the sinus durae matris of man only seldom shows the blind tubes of endothel which were described by Andres (1967)1 after investigations made in cats and dogs. 2. a) There are no tube systems lined with mesothelial cells in the tissue of the granula meningica. Usually the cellcords and cellclusters are solid. Only in exceptional cases do they have a cavity. b) There are wide spaces between the collagen fibrebundles. These spaces are filled with a thinly liquid amorphous ground substance. We observed many free cells there (especially macrophages). 3. The construction of the connective tissue of the granula meningea lead us to conclude, that they are capable of changing their volume and shape considerably. The possible functional consequences of these results were discussed.

Aged↗
PubMed1975

[Experimental investigations on cell resorption from the peritoneal cavity by use of the scanning electron microscope (author's transl)].

1. It is well known that microscopically small particles may be absorbed from the peritoneal cavity via the large lymphatic vessels. The present experiments were carried out in order to elucidate the site of the absorption. In addition, the role of transperitoneal transport of neoplastic cells as a possible cause of cancer metastases was studied. 2. The peritoneal surface of 40 rats and mice was studied with the scanning electron microscope (diaphragm, lateral abdominal wall). The investigations were carried out in 8 rats and 3 mice 24 hrs following the intraperitoneal injection of washed homologous erythrocytes and in 20 rats and 5 mice 24 hrs after the intraperitoneal injection of Ehrlich ascites tumor cells. 2 rats and 2 mice served as controls. 3. In the control animals no stomata could be shown in the peritoneum of the diaphragm or in the lateral abdominal wall. 4. The i.p. injection of erythrocytes was followed by the appearance of stomata in the peritoneal surface of the diaphragm, and absorption of erythrocytes could be demonstrated. No stomata were found in the peritoneum of the lateral abdominal wall. 5. Tumor cells were found in the stomata following the i.p. injection of ascites tumor cells. It is concluded that a lympho-hematogenous spread of tumor cells seems probable at least in the early stage of tumor infiltration of the peritoneum. This stage is followed by implantation of the tumor cells on the peritoneum.

Absorption↗