[X-ray-induced cataract as a model for investigating cataractogenesis (author's transl)]. / Die Röntgenkatarakt. Ein Modell zur Untersuchung der Kataraktogenese.

X-rays are known to be a true cataractogenic agent. Since they can be accurately dosed and directed they are particularly suitable for inducing experimental cataracts. By means of ionizing rays, lesions are induced in various lens segments. Both the extent of the damage as well as the latency period until it becomes manifest are highly age-dependent. Since lens changes effected by ionizing rays are in many respects, similar to age-related changes, experimental cataracts induced by X-rays provide suitable models for investigating processes involved in the multifactorial genesis of senile cataract.

[Image characteristics of the computer tomograph (author's transl)]. / Abbildungseigenschaften der Computertomographie. II. Räumliches Auflösungsvermögen, Dichteauflösung und Partial-Volume-Effekt bei kugelförmigen Objekten verschiedenen Durchmessers.

In the present paper the images produced by spheres of varying diameter (d = 4,6,8,10 mm) embedded in a homogeneous substance of varying densities (H' = 3,48,93,137 Hounsfield units) as produced by computer tomography were studied. Measurements show that for each sphere diameter there is a minimum contrast between the substance of the sphere and its surroundings which must exist in order to show this sphere by computer tomography. It was also shown that the partial volume effect is of significance for the attenuation of the spheres. The effect of the position of the spheres within the slices to be imaged was studied. The results clearly indicate that in the investigation of small tissue changes in the body, the thickness of the slice and patient displacement should be kept as small as possible.

[Influence of radiation-induced electrolytic shifts upon the metabolism: VII. On the question of equivalence of K+-loss and Na+-uptake (author's transl)]. / Uber den Einfluss strahlenbedingter Elektrolytverschiebungen auf den Stoffwechsel. VII. Zur Frage der Aquivalenz von K+-Verlust und Na+-Aufnahme.

Irradiated and nonirradiated yeast cells in three different metabolic conditions were incubated with four different culture mediums at various K+/Na+-concentrations and with or without glucose. The losses of K+ and the incorporation of Na+ are analysed after five hours and represented as balance values. Equivalent shifts appear in metabolic stagnation but not with metabolizing cells. The balance values nevertheless are equal in irradiated and in nonirradiated samples. This means that the radiation-induced additional exchange always is equivalent. This finding indicates a membranous modification as cause of radiation-induced electrolytic shifts.