Ultrasonic induction of sister chromatid exchanges in human lymphocytes.

We analyzed sister chromatid exchange (SCE) frequencies as an indicator of DNA damage induced in human lymphocytes by 'real-time' ultrasound. A range of exposure times and intensities was tested in a series of blind, randomized, in vitro experiments under spatial and sonographic conditions simulating exposure of a gravid abdomen and uterus. Our studies showed small but consistent effects of ultrasound on SCE frequencies, for each experiment.

[Possibilities and limits for palsied children in the general polytechnical school (author's transl)].

Some children with cerebral palsy attend the ten-form general polytechnical school. To this end, several prerequisites have to be fulfilled and other essential arrangements to be developed in cooperation with specially trained teachers. The learning conditions have to be fitted to the improving abilities of children during the educational process.

Comparative studies on the metabolism of oestradiol in the brain, the pituitary and the liver of the rat.

Radioactive oestradiol was incubated with homogenates of hypothalamus, pituitary and liver and slices of cortex, hippocampus, hypothalamus, pituitary and liver of ovariectomized rats. 2- and 4-substituted oestrogens were the main metabolites in the brain and were found in the same proportions. In the liver only the 2-substituted oestrogens were the main metabolites, while the 4-substituted ones were of minor quantitative importance.

The haemolytic effect of phallolysin.

Phallolysin from the toadstool, Amanita phalloides, is a basic protein that causes direct haemolysis of red cells. The dose-response curve is steep; the pH optimum is in the weakly acid range. The rate of haemolysis increases with the concentration of the lysin, the optimal temperature is 20 degrees C.