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R Hildebrand

Publications and source records attributed to R Hildebrand.

At least 19 recordsLinked to original sources
PubMed1992

[Microscopic anatomy from the viewpoint of the macroscopic anatomist: the Vienna anatomist Joseph Hyrtl and his microscopic injection specimen].

Mainly due to an intellectual opposition to microscopy the promising early investigations in this field had come to an untimely end resulting in a neglect of the microscope during the 18th century. In this situation micro-injected specimens were to become an important link on the way to the microscopical science of histology establishing in the first half of the 19th century. Starting without optical instrumentation on the solid grounds of visual experience injected vessels and ducts provided a pathway from well known macroscopical into unknown microscopical dimensions. Without changing their level of perception anatomists could look through a microscope with macroscopist's eyes. Under this aspect Joseph Hyrtl's specimens are not part of a systematic microscopic anatomy or histology but technically demanding preparations to study body morphology and function by comparative anatomy.

Anatomy↗
PubMed1992

[Anatomy and revolution of the human image].

In Bourgery's and Jacob's "Traité complet de l'anatomie de l'homme", Paris 1831-1854, the révolution Davidienne had been introduced into the plates of anatomical atlasses. Unlike the Vesalian tradition of representation this demarcation against an old world provided a new picture of man in medical illustration. The cultural development taking us to this point is discussed against the background of converging movements in art and medicine in late 18th century France evolving sovereign man as a modern individual.

Anatomy↗
PubMed1989

[The Würzburg anatomist Albert von Koelliker and his relations with Camillo Golgi and Santiago Ramón Cajal].

The great anatomist Albert von Koelliker (1817-1905) from Würzburg played an essential role in the histology of nervous tissue and in the development of the neuron theory in particular. He was among the first to appreciate the silver chromate method for staining nerve cells developed by Camillo Golgi and to accept and confirm the results of the neurohistological investigations presented by Santiago Ramón y Cajal with a modified technique of the Golgi method. Koelliker gave his unstinted support to both scientists whom he introduced into the international scientific community of the late 19th century. Though in the controversy about the organization of the nervous tissue Koelliker supported Cajal's view of a neuronal organization in contrast to Golgi's idea of a reticular organization, he remained a close friend to both scientists and even went all out for a nomination of Golgi for the Nobel-Prize for Physiology or Medicine.

Anatomy↗
PubMed1988

The cranial nerves as living morphotic entities--Friedrich Arnold's Icones nervorum capitis, Heidelberg 1834.

Friedrich Arnold's neuroanatomical treatise Icones nervorum capitis published in its first edition in Heidelberg 1834 ranks scientifically and iconographically among the most brilliant works of 19th century anatomical literature. Consonant with Arnold's conceptions the lithographed engravings depict the cranial nerves as living, morphotic entities comprising their topographical origin and periphery in a distinctness and beauty never been seen before.

Anatomy↗
PubMed1986

Image analysis of the histochemical demonstration of glucose-6-phosphatase activity in rat liver.

Activities of histochemically demonstrated glucose-6-phosphatase were quantified by computerized densitometry using image analysis in livers of female adult Wistar rats fed ad libitum and fasted 22 h before sacrifice. Mean optical densities along the path between small portal tracts and efferent hepatic venous branches and enzyme activities obtained from biochemical assays exhibited a strong positive correlation. The gradients of high periportal to lower perivenous glucose-6-phosphatase activities were analysed by profiles of optical density along these distances. Mapping optical densities in an image of equidensity range provided information on the distribution pattern of hepatic glucose-6-phosphatase over an extended two-dimensional area. This visualisation of histochemical enzyme reaction based on quantitative data supports the approach of sampling across the entire protal----hepatic venous distance disregarding parenchymal zonation. Utilities provided by computer assisted image analysis will have some bearing for further adequate quantitative description of liver function and structural make up.

Animals↗
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↗
PubMed1976

[Investigation on the morphokinetic reactions of the rat liver to ether anaesthesia of different length (author's transl)].

The nuclear volumes were measured in the central, intermediate and peripheral zone of the classic liver lobule of adult male albino rats exposed to ether anaesthesia lasting 15, 40 and 80 min. Related to control animals there was a significantly lower nuclear size after a 40 min duration of narcosis and a significant higher volume after 80 min in the central part of the lobule. With a slight but not significant decrease of nuclear volume in the intermediate zone after 15 min and a significant increase after 80 min respectively, the peripheral lobular region constantly showed significantly smaller nuclei. But here, too, a disappearance of decrease was recorded after 80 min. The interpretation of the data is based upon a typical distribution of cell organelles, enzymatic pathways, and metabolites in the different zones of the hepatic lobule. The intensity of reaction and appearance of diminution in nuclear volume, indicating a functional depression and probably accentuated by a circular dependent low O2-tension of tissue, is interpreted in connection with different local concentrations of ether. An improvement of the blood flow by augmental local metabolites and an increased arterial influx presumably support the recovery and favour a concentration-dependent induction of microsomal enzymes in the central part of the lobule especially.

Anesthesia, Inhalation↗