Search PubMed⌕ Search

Biomedical subjects

R Hildebrand

Publications and source records attributed to R Hildebrand.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Contribution of Würzburg anatomy to the development of microscopic anatomy studies (1847 Kölliker--Petersen 1940)].

Under K olliker 's direction the Department of Anatomy of the University of W urzburg had developed into a centre in histological science influencing strongly education in microscopical anatomy. K olliker 's textbooks, lectures, demonstrations, and courses became a model for teaching histology not only in Germany but in foreign countries, too. St ohr improved K olliker 's methods developing and adopting modern ways in teaching. With Braus and Petersen a new concept was introduced into anatomy delineated in Petersen's histological textbook for the microscopical anatomy in particular. The description of the organism in its living entirety organized in living elements is regarded as the general task when investigating living systems.

Anatomy↗
PubMed1984

[Note on the smoothing of time series].

For smoothing of time series instead of the method introduced by Kulenkampff and Kolb as a simple mathematical procedure weighted moving averages are proposed.

Animals↗
PubMed1983

Karyometric investigation on circadian rhythmic changes in the periportal and perivenous zones of the acinus of the rat liver.

In untreated adult male albino rats changes in nuclear volume within the periportal and the perivenous zones of the liver acinus were measured during a full day and night cycle. Only the perivenous zone displayed circadian rhythmic changes as expressed in the sinus-like course of the nuclear volume-distribution graph (polynomial) with a maximum between 16.00 h and 18.00 h and a minimum at 8.00 h. In all groups studied zonal heterogeneity of the means of nuclear volume and the percent-distribution graphs of nuclear volume classes were retained during the full cycle. Within each zone, however, distribution curves of nuclear volume classes were homogeneous indicating an equally directed trend in time-dependent changes in nuclear volume.

Animals↗
PubMed1983

Microbiochemical approach to liver cell heterogeneity around terminal hepatic venules.

Using lyophilized cryostat sections of liver the activities of alanine aminotransferase, lactate dehydrogenase, and pyruvate kinase were measured using a Lowry technique in the first layer of hepatocytes adjacent to terminal hepatic venules and in the residual parenchymal of the perivenous zone of the acinus in normally fed adult male Wistar rats. Alanine aminotransferase was homogeneously distributed in the two areas measured (ratio hepatocytes adjacent to terminal hepatic venules/residual parenchyma of the perivenous zone: 1.05). Enzyme activities of the lactate dehydrogenase were significantly lower in the hepatocytes adjacent to terminal hepatic venules (ratio: 0.65) and those of the pyruvate kinase significantly higher (ratio: 1.12) than in the residual parenchyma of the perivenous zone indicating liver cell heterogeneity in this zone of the liver acinus.

Alanine Transaminase↗
PubMed1983

[F. V. Raspail, founder of histochemistry and pioneer of the cell theory, reflected in contemporary medals].

Contemporary medals on F. V. Raspail are not related to the pioneering scientist, founder of histochemistry and pioneer of cell theory. They show the politician Raspail on cheap coinage popular as a souvenir and sign of political following. Raspail's personality and political mind made science and politics inseparable for him. For the general public Raspail first of all was a political man.

Cell Biology↗
PubMed1980

[Efficient measurement of cell nuclear volume].

The construction of a size sheet transilluminated from beneath for Eichner's method of nuclear measurements is described. By its equal adequate illumination the apparatus enables a timesparing and exact recording of data.

Cell Nucleus↗
PubMed1977

[Morphokinetic reactions in the thyroid, parathyroid, and tracheal glands of the albino rat after anaesthesia with thiobutabarbitone sodium and diethyl ether (author's transl)].

A significant decrease was observed in nuclear volume of the follicular cells of the thyroid gland and the cells of the parathyroid of albino rats subjected to ether anaesthesia, in contrast to generally unchanged nuclear size in animals anaesthetized by thiobutabarbitone sodium. It is suggested that ether exerts its depressant influence mainly by direct action on the function of the follicular cells of the thyroid. Thiobutabarbitone Sodium probably influences thyroid function especially by its antithyroid-drug effects, which have been reported by other authors. The highly significant increase of nuclear volume in the tracheal glands during ether narcosis is referred to the mucous secretion activating stimulus of ether vapors.

Anesthesia↗
PubMed1977

[Quantitative morphological investigation of the effect of thiobutabarbitone sodium anaesthesia on the endocrine and exocrine pancreas of the albino rat (author's transl)].

In respect of controls the beta-cells of the Islets of Langerhans in fed rats showed a significant decrease in nuclear volume after 40 min of anaesthesia with Thiobutabarbitone Sodium in a double-maximum-load dose. The alpha-cells and the cells of the exocrine pancreas do not show such alteration. The reduction in beta-cell acitivity is referred to a time and dose dependent effect of narcosis on the metabolism of the beta-cells and possible membrane phenomena. According to the morphological picture the otherwise missing signs of impaired function of the cells indicate a peripheral disturbance of glucose utilization during nacrosis. The blood-sugar levels support the proposed explanation.

Anesthesia↗
PubMed1976

Comparative electron-microscopic studies on the conus papillaris and its relationship to the retina in night and day active geckos.

The ultrastructure of the capillary endothelium of the conus papillaris within the vitreous body was studied in night, day, and mixed (night and day) active geckos (Homopholis wahlbergi, Gekko gecko, Pachydactylus bibronii, Tarentola mauritanica, Lygodactylus conraui, Phelsuma guimbeaui, Phelsuma madagascariensis). Capillary endothelial cells were poorly developed in night and mixed active animals, whereas in day active animals they were highly organized. In particular the number and height of the luminal and basal microvilli and the frequency of micropinocytotic vesicles were distinctly increased in day active geckos. It is assumed that these structural mechanisms improve the transendothelial transportation capacity of metabolic substances. When the thickness of the retinal layers was compared, we found that the inner retinal layers of those geckos in which the conus capillaries were poorly developed, were approximately 60% of the thickness of the inner retina in the day active geckos. The results indicate that the structural organization of conal endothelial cells is related primarily to the retinal structure rather than to the animals' daytime behavior. Furthermore, our observations support the theory that the conus papillaris of lizards, like the pecten oculi of birds, has a primary function in the nutrition of the avascular retina and/or is involved in the exchange of fluid in the vitreous.

Animals↗
PubMed1976

[Morphokinetic reactions in the adrenal gland of the albino rat after anaesthesia with inactin (author's transl)].

A marked decrease in the nuclear size in the adrenal medulla and a slight increase in the nuclear volume of the zona glomerulosa was found in the Inactin anaesthetized Wistar rat. The nuclear volumes in the zona fasciculata did not show any alteration. The influence on the activity of the cells in the adrenal medulla is supposed to be due to a depression in the central nervous system by Inactin. The slight activation of the zona glomerulosa is attributed to stimulation of the renin-angiotensine-system by an Inactin induced change in renal function. A failing dose dependent effect is taken as a sign of compatibility of the administered drug.

Adrenal Glands↗
PubMed1976

[Quantitative morphological investigation of the effect of ether anaesthesia on the kidney of the rat (author's transl)].

In the proximal and distal convoluted segments and the collecting tubule of the kidneys of 24 male albino rats, type Wistar TNO W 70 SPF, the nuclear volume was measured after the animals had been anaesthetized with ether for 15, 40 and 80 min. In contrast to nontreated controls there was a decrease in average nuclear size of 12.6% and 11.1% after 15 and 40 min in the proximal convoluted segment. Changes in nuclear size could not be detected in the distal convoluted segment and in the collecting tubules. While the decrease in the nuclear volume in the proximal convolution is considered to be a direct effect of ether, the enhanced reabsorption of sodium mentioned in other studies could be explained by an alpha-receptor mediated transport effect of the narcotic agent.

Anesthesia, Inhalation↗