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Biomedical subjects

K Theiler

Publications and source records attributed to K Theiler.

At least 19 recordsLinked to original sources

[Hereditary drusen in Bruch's membrane].

The left eye of a 71-year-old patient who had suffered from choroiditis guttata was removed immediately after death by enucleation. Histopathological studies revealed numerous nodular (hard) drusen, a wide variety of senile alterations of the pigment epithelium and Bruch's membrane, and the presence of multiple corpora arenacea in the subarachnoid space of the optic nerve. A new hypothesis concerning the development of hereditary drusen is advanced, postulating a disturbance of the lysosomal enzyme/inhibitor balance.

Aged

Low set ears (Lse), a new mutation of the house mouse.

A new dominant mutation, low set ears (Lse), in the mouse may be indicative of a mammalian branchial arch syndrome. This developmental anomaly of the external ear is accompanied by eye defects, retarded growth and shortened lifespan. The ear defect can be identified in 13-day embryos. Further studies will determine the effects of the Lse gene on other systems.

Animals

Development of rib-vertebrae: a new mutation in the house mouse with accessory caudal duplications.

The new recessive mutation rib-vertebrae (rv) causes fusions of lower ribs and malformations of vertebrae, which results from disturbed somite arrangement. In addition, duplications of the caudal neural tube and sometimes unilateral suppression of kidney formation can be observed. The new mutation is compared with the six already known mutations in mice with "Wirbel-Rippen-Syndrome" and with a similar syndrome in man. From the various effects of the rv-gene observed, it is suggested that the gene causes abnormal inner and outer surface formation, producing manifold secondary effects.

Animals

Studies on hereditary retinal degeneration. The rd gene in the mouse.

Stearic, oleic, linoleic, arachidonic, and docosahexaenoic acids can be detected regularly in the eyes and retinae of mice. During the period of maturation of the outer segments of the rod, the amount of each fatty acid increases, the most striking feature of which is the accumulation of docosahexaenoic acid in the retina, which might reflect the growth of rod outer segments. In rd/rd mice, fatty acid synthesis is reduced and the change characteristic of docosahexaenoic acid is absent. Analysis of the structure of outer segment disc membranes by the freeze fracturing technique, however, shows that the structure of the membrane is probably not affected by the rd gene.

Animals

Development of velvet coat (Ve/Ve), another early lethal mutation in the house mouse.

A new semidominant mutation in the house mouse, velvet coat (Ve), is described. Ve homozygotes, recognizable on day 5 of gestation by their deficiency of ectodermal cells, never produce mesoderm and are resorbed by days 9-10. Primary Ve action may occur during the formation of the blastocyst or during determination and differentiation of the inner cell mass, or both. Accordingly, Ve/Ve embryos may provide a useful model for investigating primary gene action during blastocyst formation and subsequent differentiation.

Animals

Development of Dickie's small eye, a mutation in the house mouse.

A new semidominant mutation in the laboratory mouse, Dickie's small eye (Dey), is described. It is localized on chromosome 2. Heterozygotes show reduced body size, small eyes with coloboma, small or lacking lens with cataract, abnormal folding of the retina and reduction of the pigment layer. The anterior chamber is usually missing. Homozygotes apparently die early in pregnancy.

Animals

A new allele of ocular retardation: early development and morphogenetic cell death.

The inheritance and some developmental effects of a new allele of ocular retardation (orJ) are described. Affected animals or 12 days of gestation, show reduced cell death in the eye cup and thickening of the inner wall of the optic fissure. At 11 to 13 dyas of gestation orJ/orJ eyes grafted to the testis do not produce retina as their orJ+ littermates do. Adult animals have small eyes with closed lids, abnormal retinal layers, and no optic nerve.

Alleles

[On aplasia of the optic nerve (author's transl)].

The occurrence of aplasia and hypoplasia of the optic nerve in man and in mammals is described. A secondary aplasia may result from additional malformations of the central nervous system. Primary aplasia may be studied in mutants of the house mouse, which show that not only the blood vessels, but also changes in time and location of the physiologic cell necrosis may be important.

Abnormalities, Drug-Induced