Biomedical subjects

F M Barrett

Publications and source records attributed to F M Barrett.

12 recordsLinked to original sources

PubMed1988

Ultrastructural localization of phenoloxidases in cuticle and haemopoietic tissue of the blowfly Lucilia cuprina.

The ultrastructural localization of two types of biochemically characterized phenol oxidase activity is described in the larva of the sheep blowfly, Lucilia cuprina. Cuticular tyrosinase activity (enzyme A) is seen in epicuticular filaments and procuticle. Procuticle activity can be detected only after a presumed process of activation takes place in damaged cuticle. By using either the dopamine reaction or inducing melanization by hot-water treatment, tyrosinase is readily shown in haemopoietic tissue which, in L. cuprina, occurs subdermally as well as being associated with the dorsal vessel. The adaptation of the diaminobenzidine technique, used to stain laccase in electrophoretic gels, to ultrastructural cytochemistry has made it possible to demonstrate enzymic activity probably due to laccase (enzyme B). The laccase activity is present in the inner epicuticle of late wandering third instar larvae (about to pupariate) but is not present in the epicuticle of younger larvae.

3,3'-Diaminobenzidine↗

PubMed1980

Sexual experience, birth control usage, and sex education of unmarried Canadian university students: changes between 1968 and 1978.

Changes in coital experience, birth control usage, and sex education between 1968, 1971, 1974, and 1978 were studied in unmarried Canadian university students. The percentage of coitally experienced females increased from 32% in 1968 to 58% in 1978 and of males from 40% to 62%. There was no significant change between 1974 and 1978 for either sex, nor were there sex differences in coital experience in either year. Coitally experienced females were more likely to have had intercourse in the 3 months preceding both 1974 and 1978 surveys, but otherwise there were no sex differences in coital frequency, lifetime number of coital partners, or age at first intercourse. Religion was a more reliable indicator of coital experience in 1968 than in 1978. Males were more likely than females to report postpubertal sexual contacts which they classified as homosexual (16.5% vs. 7%) whereas 12-13% of both sexes reported no sexual contacts of any kind with another person. Contraceptive risk-taking was high at first intercourse and among those having infrequent coitus. However, both this group and more coitally active students were less likely to take such risks in 1978 than in 1968, almost entirely because of increased pill use. Coitally experienced vs. inexperienced students differed in their ranking of the major influences on their knowledge and attitudes about sex.

Abortion, Induced↗

PubMed1977