Comparisons of dermatoglyphic patterns in monochorionic and dichorionic monozygotic twins.

The data presented here indicate that different influences affect dermatoglyphic pattern development in MC-MZ and DC-MZ twins. Only five of 84 variables had significant mean differences but their clustering suggested a real difference in mean placement of the atd angle. Nineteen of 84 variables had significantly different within-pair mean squares for the two twin types.

[A new method for elimination of artifacts produced by collimator septum effect in gamma-camera images (author's transl)].

Collimator artifacts may be present within the images produced by collimators whose septal width approaches the inherent resolution of the gamma-camera system. As the inherent resolution of the gamma-camera is improved, collimator artifacts become more prominent. The purpose of this study is to eliminate collimator artifacts from gamma-camera images.

Antileukemic principles isolated from euphorbiaceae plants.

Extracts of Euphorbia esula L. and Croton tiglium L., two members of the Euphorbiaceae which have been used widely in folk medicine for treating cancers, showed antileukemic activity against the P-388 lymphocytic leukemia in mice.

Chromosome aberrations induced in vitro by low doses of radiation: nondisjunction in lymphocytes of young adults.

Epidemiological studies suggest radiation exposure as a cause of meiotic non-disjunction in humans, but experimental evidence with cytological proof has been lacking. Our results indicate that mitotic nondisjunction of lymphocyte chromosomes can also be induced by exposure to a low dose of radiation. Abnormal segregation can be induced not only when the cells are irradiated but also when nonirradiated cells are incubated with irradiated cell-free plasma or serum.

Radiation-induced chromosome aberrations in mouse spermatocytes and oocytes.

ICR/Swiss males and females were exposed to 300 R whole-body gamma irradiation. The frequency of aberrations in metaphase I chromosomes recovered from oocytes cultured in vitro was compared with those recovered from spermatocytes irradiated in pachytene and diplotene. The ability of oocytes collected 1 day postirradiation to mature in vitro was not affected, but significantly fewer oocytes cultured 5 days after irradiation matured.

Identification of triploid genome by fluorescence microscopy.

Fluorescence markers on chromosome numbers 3, 13, and 14 gave cytological evidence of the paternal origin of the extra haploid set in a premature triploid infant with XXY sex chromosome complement. The mother had discontinued the use of oral contraceptives 13 months prior to conception. It is not possible to tell whether the mechanism involved was fertilization by dispermy or by a diploid sperm.