Enzyme replacement in Tay-Sachs disease.

Enzyme replacement therapy was attempted with two Tay-Sachs-diseased individuals--a 14-month-old child and a 7-week-old infant. Treatment consisted of repeated weekly intrathecal injections of pure hexosaminidase A. Injection of this enzyme resulted in almost complete disappearance of GM2 from the serum, but did not bring about dissolution of the GM2 membranous cytoplasmic bodies in the brain, as detected by electronmicroscopy.

Affiliation before and after child delivery as a function of repression-sensitization.

A group of 177 women were asked, before and after child delivery, to state their preference for being alone or with other women. They were also asked to rank their level of anxiety. After delivery they filled out the Repression-Sensitization Scale of Byrne, Barry & Nelson (1963).

A survey of amniocentesis in 925 patients at high risk of fetal genetic disorder.

Over a nine-year period, 925 pregnancies at an Israeli medical centre were selected for investigation by amniocentesis for genetic reasons. In only 30 pregnancies did failure of laboratory methods or difficulty with amniocentesis lead to a lack of results with which to assess the normality of the fetus. The information obtained by examination of the amniotic fluid in the other 895 pregnancies is presented and discussed.

Genetic and environmental correlations between brain weight and maze learning in inbred strains of mice and their F1 hybrids.

The relationships among body weight, cerebellum weight, cerebrum weight, maze-learning ability in a double T-maze, and discrimination learning in a Y-maze were studied in six inbred strains of mice and some of their F1 hybrids. The subjects were 131 male albino mice from 14 genotypic groups: five inbred groups and nine groups of crossbred offspring. Intra- and intergroup correlations were computed between all possible pairs of the anatomical and behavioral traits.

Prenatal diagnosis of Tay-Sachs genotypes.

Hexosaminidase activity was determined in cultured and uncultured amniotic fluid cells taken from seven pregnant women who had previously given birth to infants with Tay-Sachs disease. Complete deficiency of hexosaminidase A was found in one case, indicating a Tay-Sachs fetus. The diagnosis was confirmed on examination of various tissues after therapeutic abortion.