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Biomedical subjects

S Tilgner

Publications and source records attributed to S Tilgner.

At least 19 recordsLinked to original sources
PubMed1991

[Postnatal cellular pleomorphosis in retinal pigment epithelium].

Selected features of cell morphology of the retinal pigment epithelia (RPE) were compared in newborn (42 eyes) and adult albinotic rats (34 eyes) at the age of 9 months. The RPE of newborn rats was found to consist of nearly homeomorphous, hexagonal, mononucleate, and relatively small cells (monomorphism). Minimal regional differences were found to exist. In adult albinotic rats the density of the RPE cell population was found to be considerably reduced, but the cells and nuclei were generally enlarged. A high percentage of RPE cells was found to contain two nuclei, and as a rule there were always some cells with three, four or even more nuclei. The picture of the cell mosaic was characterized by marked pleomorphism with regionally determined graduation. Pleomorphous changes were more pronounced in the central than in the more peripheral areas. The genesis and dynamics of cellular pleomorphism are also discussed.

Animals↗
PubMed1990

[Retino-hypothalamic pathways in vertebrates].

Forty years ago Hollwich (1948) introduced the conception of an "energetic portion of the visual pathway". Contributions to this conception of a direct connection of the retina with the hypothalamus accumulated since then and summarized here in tabular form give rise to the following conclusions: In fish the main hypothalamic termination of retinofugal axons is the nucleus hypothalamicus opticus. It may pass for the suprachiasmatic nucleus of fishes. In amphibians retino-hypothalamic fibres project to the area praeoptica. In reptiles retinofugal fibres innervate hypothalamic neuronal populations called either Nucleus suprachiasmaticus or Nucleus praeopticus. In birds retinohypothalamic axons project to a circumscribed anterior hypothalamic area termed "suprachiasmatic nucleus" by some authors. In mammals at last the main part of the retinohypothalamic tract terminates in the suprachiasmatic nuclei, especially favouring their caudal and ventrolateral parts. The interneuronal connections are axo-dendritic synapses of the Gray Types-I and II. Connections of retinal neurons, especially with suprachiasmatic hypothalamic nuclei or their homologues, are by now well established facts. They represent relatively constant and phylogenically stable components of the centripetal retinal projection. These projections are probably in all, certainly in most of the vertebrates bilateral. Some former but also newer methods of research (Stumpf and Sar, 1975) also depicted optic fibers which terminate in hypothalamic sites apart from the nucleus suprachiasmaticus and the area hypothalamica anterior (Conrad and Stumpf, 1975). A review of the literature on the existence of nerve fibers directly connecting the retina with the hypothalamus is tabulated.

Animals↗
PubMed1977

[Experimental allergic chorioretinitis. Appearance and behavior of complement-fixing anti-ROS antibodies in the sera following immunization with retinal antigens (author's transl)].

The authors studied the appearance and behavior of complement-fixing anti-ROS antibodies in the sera of GrCh rabbits following one or two intracutaneous injections of retinal antigens emulsified in Freund's complete adjuvant (KFA). Fourteen different antigenic preparations from heterologous, homologous, and autologous retinal components incorporated in KFA were tested and compared. Apart from the supernatant of a centrifuged homogenized preparation of homologous retina, all immunogens generally induced anti-ROS antibodies. The antibody titers (reciprocal values) reached a maximum 4 to 8 weeks post injection, at only low levels. The changes in antibody concentrations showed some relationship to the quality and dose of the immunogens. Anamnestic effects following reinjection reached maximum values within as little as 5 to 14 days. Animals not developing chorioretinitic lesions showed higher antibody titers more frequently than rabbits with clinically confirmed disease. Provided there is sufficient relevance of the humoral reactions observed, the complement-fixing antibodies we found in our experiments are more likely to have protective than pathogenic functions.

Animals↗
PubMed1977

[Genetic differences in the eye manifestation of adjuvant arthritis in the rat. II. Histological investigations (author's transl)].

Hooded rats react to intracutaneous injections of complete Freund's adjuvant with an adjuvant disease, which is externally perceivable by massive polyarthritis, by skin and ear nodules, and by other known symptoms. In contrast to Wistar rats, however, they show no tendency to develop clinically or histologically provable eye manifestations such as an uveitis anterior (adjuvant uveitis). This fact has been connected with the genetic differences between the two strains of rats.

Animals↗
PubMed1977

[To some aspects of iris morphology in vertebrates (author's transl)].

The multiplicity of colorations and patterns in the irides as well as the pupillary polymorphism in vertebrates are impressing. They show the iris as an ocular part especially inclined to evolutional modifications. Species from different classes of vertebrates not uncommonly show very similar characteristics of iris morphology provided their mode of life is comparable with regard to relevant factors. On the other hand there exist many examples of very differing iris characteristics in spite of seemingly well corresponding habits of life. These cases often enough pose problems concerning the biological value of a specific variant form. They point however to a multifactorial conditioning of these phenotypic characteristics indicating simultaneously possibilities to create identical effectivities by differing means.

Amphibians↗